APPARATUS, SYSTEM AND METHOD FOR PAIN MONITORING
20180310877 ยท 2018-11-01
Inventors
Cpc classification
G16H50/20
PHYSICS
A61B5/7264
HUMAN NECESSITIES
A61B5/02416
HUMAN NECESSITIES
A61B5/0075
HUMAN NECESSITIES
A61B5/4848
HUMAN NECESSITIES
A61B5/40
HUMAN NECESSITIES
A61B5/7278
HUMAN NECESSITIES
A61B5/318
HUMAN NECESSITIES
A61B5/11
HUMAN NECESSITIES
A61B5/398
HUMAN NECESSITIES
A61B5/7225
HUMAN NECESSITIES
A61B5/02055
HUMAN NECESSITIES
A61B5/746
HUMAN NECESSITIES
A61B2562/0219
HUMAN NECESSITIES
International classification
A61B5/00
HUMAN NECESSITIES
A61B5/0205
HUMAN NECESSITIES
A61B3/11
HUMAN NECESSITIES
Abstract
A nociception monitoring device including at least one sensor configured to sense at least three physiological parameters of a patient, and a computing unit configured to receive the at least three physiological parameters and to compute a nociception scale (NS) value, indicative of a nociception level of the patient, based on an analysis of the at least three physiological parameters and/or features derived therefrom.
Claims
1. A nociception monitoring device comprising: at least one sensor adapted to sense at least three physiological parameters of a patient, and a computing unit adapted to: receive said at least three physiological parameters from said at least one sensor; compute a nociception scale (NS) value based on an analysis of said at least three physiological parameters and/or features derived therefrom, wherein said NS value is indicative of a nociception level of the patient; and wherein said NS value is essentially unaffected by vasodilating and/or bradycardial effects caused by administration of an analgesic and/or an anesthetic to the patient.
2. The device of claim 1, wherein when said NS value crosses a first predefined threshold value a mild nociception level is identified; and wherein when said NS value crosses a second predefined threshold value a severe nociception level is identified.
3. The device of claim 1, wherein an essentially unaffected NS value is an NS value changed by less than 10 units.
4. The device of claim 1, wherein said patient is anesthetized or administered with an analgesic.
5. (canceled)
6. The device of claim 4, wherein said NS value enables differentiation between no nociception, mild nociception and/or severe nociception in said patient administered with said analgesic.
7. (canceled)
8. The device of claim 4, wherein said NS value provides regression of the nociception level into a numerical scale.
9. The device of claim 1, wherein said at least one sensor is selected from a biopotential sensor, a galvanic skin response (GSR) sensor, a plethysmography (PPG) sensor, an electrocardiograph (ECG), an electrooculograph (EOG), an electromyograph (EMG), a facial electromyograph (FEMG)/electroencephalograph (EEG), an electro-gastro-gram (EGG), a laser doppler velocimeter (LDV), a skin temperature sensor, an internal body temperature sensor, a respiration sensor, a capnograph, a pupil diameter monitor, a us blood pressure sensor, a three-axis accelerometer, a diffused correlation spectroscopy (DCS) sensor, an acoustics sensor, a bio-impedance sensor and a piezoelectric sensor, an audio sensor, motion sensing input device or any combination thereof.
10. The device of claim 9, wherein said at least one sensor is selected from a galvanic skin response (GSR) sensor, a plethysmography (PPG) sensor, a skin temperature sensor, and a three-axis accelerometer or any combination thereof
11. The device of claim 10, wherein said at least one sensor comprises at least a galvanic skin response (GSR) sensor and a plethysmography (PPG) sensor.
12. The device of claim 1, comprising at least three sensors; wherein said at least three sensors comprise at least a galvanic skin response (GSR) sensor, a plethysmography (PPG) sensor and a skin temperature sensor, or at least a galvanic skin response (GSR) sensor, a plethysmography (PPG) sensor and a three-axis accelerometer.
13. (canceled)
14. (canceled)
15. The device of claim 1, wherein said at least three parameters are selected from heart rate (HR), heart rate variability (HRV) monitor, amplitude of photoplethysmogram, skin conductance level (SCL), number of skin conductance fluctuations (NSCF), blood pressure, movement and any combination thereof.
16. (canceled)
17. (canceled)
18. (canceled)
19. The device of claim 1, wherein said NS value enables differentiation between no nociception and nociception with a sensitivity of above 80% at a specificity of at least 75%.
20. The device of claim 1, wherein said NS value enables differentiation between no nociception, and nociception with a sensitivity of above 85% at a specificity of at least 75%.
21. (canceled)
22. (canceled)
23. (canceled)
24. The device of claim 1, wherein said NS value enables differentiation between no nociception and mild nociception with a sensitivity of above 75% at a specificity of at least 75%.
25. A device for determining analgesic efficacy comprising: at least one sensor adapted to sense at least three physiological parameters of a patient before (A0) and after (A1) administration of an analgesics and before (S0) and after (S1) providing a noxious stimuli; and a computing unit adapted to: receive said at least three physiological parameters from said at least one sensor obtained for A0, A1, S0, S1 and/or combinations thereof; compute nociception scale (NS) values for A0, A1, S0, S1 and/or combinations thereof based on an analysis of said at least three physiological parameters and/or features derived therefrom, and determine the efficacy of said analgesic based on a comparison of the nociception scale (NS) values obtained at A0, A1, S0, S1 and/or combinations thereof.
26. The device of claim 25, wherein determining the efficacy of said analgesics comprises determining an efficient dose of said analgesics.
27. The device of claim 25, wherein said NS value is essentially unaffected by vasodilating and/or bradycardial effects of analgesics and/or anesthetics.
28. The device of claim 25, wherein said at least one sensor is selected from biopotential sensor, a galvanic skin response (GSR) sensor, a plethysmography (PPG) sensor, an electrocardiograph (ECG), an electrooculograph (EOG), an electromyograph (EMG), a facial electromyograph (FEMG)/electroencephalograph (EEG), an electro-gastro-gran (EGG), a laser doppler velocimeter (LDV), a skin temperature sensor, an internal body-temperature sensor, a respiration sensor, a capnograph, a pupil diameter monitor, a us blood pressure sensor, a three-axis accelerometer, a diffused correlation spectroscopy (DC S) sensor, an acoustics sensor, a bio-impedance sensor and a piezoelectric sensor, an audio sensor, motion sensing input device or any combination thereof.
29. The device of claim 25, comprising at least three sensors, wherein said at least three sensors comprise a PPG sensor, a GSR sensor and a three-axis accelerometer and/or a skin temperature sensor.
30. (canceled)
31. The device of claim 25, wherein said at least three physiological parameters are selected from heart rate (HR), heart rate variability (HRV) monitor, amplitude of photoplethysmogram, skin conductance level (SCL), number of skin conductance fluctuations (NSCF), arterial blood pressure, movement and any combination thereof.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] Some embodiments of the disclosure are described herein with reference to the accompanying figures. The description, together with the figures, makes apparent to a person having ordinary skill in the art how some embodiments of the disclosure may be practiced. The figures are for the purpose of illustrative discussion and no attempt is made to show structural details of an embodiment in more detail than is necessary for a fundamental understanding of the teachings of the disclosure.
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DETAILED DESCRIPTION
[0073] In the following description, various aspects of the disclosure will be described. For the purpose of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the different aspects of the disclosure. However, it will also be apparent to one skilled in the art that the disclosure may be practiced without specific details being presented herein. Furthermore, well-known features may be omitted or simplified in order not to obscure the disclosure.
[0074] The present disclosure relates generally to monitoring nociception/analgesia, specifically to nociception/analgesia monitoring during anesthesia and pain management.
[0075] According to some embodiments, there is provided a nociception/analgesia monitoring device configured to assess the nociception level of a patient.
[0076] According to some embodiments, the patient is administered with and/or under influence of an anesthetic and/or an analgesic. According to some embodiments, the assessment of the patient's nociception level is essentially unaffected by vasodilating and/or bradycardial effects caused by the drugs administered to the patient.
[0077] According to some embodiments, the assessment of the patient's nociception level includes identifying and/or distinguishing between mild nociception and severe nociception. According to some embodiments, the assessment of the patient's nociception level includes identifying and/or distinguishing between mild nociception, moderate nociception and/or severe nociception.
[0078] As referred to herein, the terms patient may relate to a subject undergoing nociception/analgesia monitoring. According to some embodiments, the patient may refer to a subject undergoing surgery or other potentially pain inducing medical intervention. According to some embodiments, the patient may refer to a subject administered with an anesthetic and/or an analgesic.
[0079] As used herein, the terms drug and medicament may be interchangeable and may refer to any medication administered to the patient. According to some embodiments, the drug is an anesthetic and/or analgesic. According to some embodiments, the drug is an opioid. According to some embodiments, the drug is a muscle relaxant. According to some embodiments, the drug is a beta-blocker. According to some embodiments, the drug is selected from remifentanil, fentanyl, propofol, isoflurane, desflutane, sevoflurane, halotane, ketamine, thiopental, rocuronium, lidocaine, atracurium, rapacuronium, NSAIDs, Nitros-Oxide. Each possibility is a separate embodiment.
[0080] According to some embodiments, the term nociception may refer to the encoding and processing of harmful stimuli in the nervous system, including physiological responses to surgical and other clinical noxious stimuli during unconsciousness. According to some embodiments, the terms nociception and pain may be used interchangeably. According to some embodiments, nociception may refer to a physiologic process and pain as a subjective phenomenon.
[0081] As used herein, the term analgesia may refer to the relief or reduction in pain perception, including the reduction or absence of a pain perception during a painful stimulus, e.g. pain caused during surgery. According to some embodiments, the terms pain monitoring, nociception monitoring, analgesia monitoring and pain assessment may be interchangeably used.
[0082] According to some embodiments, the term nociception level may refer to a continuous and/or incremental scale of pain ranging from no nociception to severe nociception (for example, but not limited to, a numerical scale from 0-10 or from 0-100). Additionally or alternatively, a nociception level may refer to a category of nociception, such as no nociception, mild nociception, severe nociception or any other suitable category defining a level of nociception.
[0083] According to some embodiments, the term no nociception refers to a patient presenting no physiological signals and/or neural processes indicative of nociception. According to some embodiments, as used herein no nociception may refer to a nociception scale value in the range of, for example, 0-20 out of a 0-100 numerical scale.
[0084] According to some embodiments, the term mild nociception refers to patients presenting mild deviations in physiological signals and/or neural processes, as compared to no nociception. According to some embodiments, as used herein, mild nociception may refer to a nociception scale value in the range of, for example, 20-50 out of a 0-100 numerical scale.
[0085] According to some embodiments, the term moderate nociception refers to patients presenting moderate deviations in physiological signals and/or neural processes, as compared to no nociception. According to some embodiments, as used herein, mild nociception may refer to a nociception scale value in the range of, for example, 40-70 out of a 0-100 numerical scale.
[0086] According to some embodiments, the term severe nociception refers to patients presenting pronounced deviations in physiological signals and/or neural processes, as compared to no nociception. According to some embodiments, as used herein, severe nociception may refer to a nociception scale value in the range of, for example, 60-100 out of a 0-100 numerical scale.
[0087] According to some embodiments, the monitoring device may include at least one sensor. As used herein the term at least one sensor may refer to 1, 2, 3, 4, 5, 6 or more sensors. Each possibility is a separate embodiment. According to some embodiments, the at least one sensor may be incorporated into a finger probe, a wristwatch, a wristband, a glove, a chest band or any other suitable element suitable for attachment to the subject, for example, to the subject's finger, wrist or chest.
[0088] According to some embodiments, the at least one sensor is selected from a bio-potential sensor, a galvanic skin response (GSR) sensor, a plethysmography (PPG) sensor, an electrocardiograph (ECG), an electrooculograph (EOG), an electromyograph (EMG), a facial electromyograph (FEMG)/electroencephalograph (EEG), an electro-gastro-gram (EGG), a laser doppler velocimeter (LDV), a skin temperature sensor, an internal body temperature sensor, a respiration sensor, a capnograph, a pupil diameter monitor, a blood pressure sensor, an accelerometer, a diffused correlation spectroscopy (DCS) sensor, an acoustics sensor, a bio-impedance sensor, a piezoelectric sensor, an audio sensor, motion sensing input device (e.g. an image/video recorder and/or analyzer) configured to, in conjunction with suitable software, identify body or facial spasms and or twitches, or any combination thereof. Each possibility is a separate embodiment.
[0089] According to some embodiments, the monitoring device may include at least a PPG sensor and a GSR sensor. According to some embodiments, the monitoring device may include at least a PPG sensor, a GSR sensor and a three-axis accelerometer. According to some embodiments, the monitoring device may include at least a PPG sensor, a GSR sensor and a skin temperature sensor. According to some embodiments, the monitoring device may include at least a PPG sensor, a GSR sensor, a skin temperature sensor and a three-axis accelerometer. According to some embodiments, the monitoring device may include at least a plethysmography (PPG) sensor, a skin temperature sensor and a three-axis accelerometer. According to some embodiments, the monitoring device may include at least a galvanic skin response (GSR) sensor, a skin temperature sensor and a three-axis accelerometer. According to some embodiments, the at least three sensors may include at least a galvanic skin response (GSR) sensor, a plethysmography (PPG) sensor and an electrocardiograph (ECG). According to some embodiments, the at least three sensors may include at least a galvanic skin response (GSR) sensor, a plethysmography (PPG) sensor and an electrooculograph (EOG). According to some embodiments, the at least three sensors may include at least an electrocardiograph (ECG), a skin temperature sensor and a three-axis accelerometer. According to some embodiments, the at least three sensors may include at least a galvanic skin response (GSR) sensor, a plethysmography (PPG) sensor and a facial electromyograph (FEMG)/electroencephalograph (EEG). According to some embodiments, the at least three sensors may include at least an electrocardiograph (ECG), a plethysmography (PPG) sensor and a facial electromyograph (FEMG)/electroencephalograph (EEG). According to some embodiments, the at least three sensors may include at least a galvanic skin response (GSR) sensor, a plethysmography (PPG) sensor and respiration sensor. It is understood that other combinations of sensor may also be envisaged and is within the scope of the disclosure.
[0090] According to some embodiments, the at least one sensor may be configured to sense at least three physiological parameters of the patient. As used herein the term at least three physiological parameters may refer to 3, 4, 5, 6 or more physiological parameters. Each possibility is a separate embodiment. However, according to some alternative embodiments, less than three parameters may be sensed, such as one or two parameters. According to some embodiments, the at least one sensor may be configured to sense a plurality of physiological parameters of the patient. As used herein the term plurality with regards to physiological parameters may refer to more than 5 physiological parameters, more than 10 physiological parameters or any other suitable number of parameters. Each possibility is a separate embodiment. As a non-limiting example, the monitoring device may include two sensors configured to sense at least three physiological parameters.
[0091] According to some embodiments, the at least three physiological parameters are indicative of a nociception level of the patient. According to some embodiments, the at least three physiological parameters may be obtained from a same sensor and/or from different sensors. According to some embodiments, the at least three physiological parameters may be selected from blood pressure, respiration, internal and/or surface temperature, pupil diameter, galvanic skin response, and signals received and/or extracted and/or derived from ECG, PPG, EOG, EGG, EEG, EMG, LDV, capnograph, accelerometer, audio, image and/or video identifying body or facial spasms and or twitches or any combination thereof. Each possibility is a separate embodiment.
[0092] According to some embodiments, the at least three physiological parameters may be selected from heart rate/pulse rate (HR/PR)), heart rate variability (HRV) monitor, amplitude of photoplethysmogram (PPGA), skin conductance level (SCL), number of skin conductance fluctuations (NSCF), blood pressure and movement. Each possibility is a separate embodiment. According to some embodiments, the at least three physiological parameters may at least include heart rate variability (HRV), amplitude of photoplethysmogram and movement. According to some embodiments, the at least three physiological parameters may at least include heart rate variability (HRV), arterial blood pressure and number of skin conductance fluctuations (NSCF). According to some embodiments, the at least three physiological parameters may at least include amplitude of photoplethysmogram, skin conductance level (SCL) and arterial blood pressure. According to some embodiments, the at least three physiological parameters may at least include heart rate, amplitude of photoplethysmogram, and movement. According to some embodiments, the at least three physiological parameters may at least include skin conductance level (SCL), EMG Spectral Entropy and arterial blood pressure. According to some embodiments, the at least three physiological parameters may at least include heart rate variability (HRV) monitor, amplitude of photoplethysmogram, skin conductance level (SCL) and number of skin conductance fluctuations (NSCF). According to some embodiments, the at least three physiological parameters may at least include heart rate (HR), amplitude of photoplethysmogram and respiration rate. According to some embodiments, the at least three physiological parameters may at least include skin conductance level (SCL), EEG coherence, amplitude of photoplethysmogram. According to some embodiments, the at least three physiological parameters may at least include skin conductance level (SCL), EEG Spectral Entropy and movement. It is understood that other combinations of parameters and combination of parameters may also be envisaged and are within the scope of the present disclosure. According to some embodiments, the at least three physiological parameters may refer to a derivative and/or features of the parameter, a moving average of the parameter, a value of the parameter or its derivative obtained during a moving window, derivatives of the parameter in time and the like. According to some embodiments, a derivative of the parameter may refer to any value derived from the parameter by filtering, averaging, and/or other mathematical or statistical processing.
[0093] According to some embodiments, the at least three physiological parameters include features derived from physiological signals obtained from the sensors. As used herein, the terms features, physiological features and extracted features may be interchangeably used and may refer to at least one or more physiological features that may be extracted and/or derived from sensor signals. The features may be quantitative or qualitative.
[0094] According to some embodiments, a plurality of features may be derived from the physiological parameters of the patient. As used herein the term plurality with regards to features may refer to more than 5 physiological parameters, more than 10 physiological parameters, more than 15 physiological parameters or any other suitable number of parameters. Each possibility is a separate embodiment.
[0095] According to some embodiments, the features may be derived using feature extraction techniques and may include combining a plurality of extracted features, for example, by non-linear regression techniques.
[0096] Within the context of the present invention the terms feature extraction, feature processing and signal processing may refer to the processes, manipulations and signal processing measures performed to analyze a physiological parameter. Non-limiting examples of suitable physiological features are depicted in table 1, below.
TABLE-US-00001 TABLE 1 physiological features Number of features Signal Feature Description 15 ECG Q/R/S/T/P Amplitude, moving average amplitude and variability of amplitude, amplitude of the Q/R/S/T/P pulse-an array that represent average and the location and the amplitude of the peak variability 15 ECG RR/PQ/PR/ The interval, moving average of interval and variability QT/RS of interval between each pulse or between internal pulse interval, waves, an array that represent the location of the value average and computed, a sthe first peak location and its relevant variability interval 1 ECG P wave Width of the P wave-an array that represent the location width of the P peak and P wave relevant width 1 ECG ST level The point of inflection after S wave, which defines beginning of ST segment. An array that represent the location and point amplitude. 5 ECG Q, R, S, T, P Derivative of the Amplitude amplitude change 5 ECG RR/PQ/PR/ Derivative of the pulses intervals QT/RS interval change 1 ECG ST level Derivative of the ST level change 1 ECG QRS width Derivatives of width of the QRS complex change 1 ECG Energy of Computing the energy of the residues after applying the ECG spectral cleaning and after applying auto regressive residues methods 1 ECG Number of Number of missing R-peaks for a certain time window missing R peaks 4 ECG R-R Power (area) of the VLF, LF, MF and HF frequencies Freq. Variability analysis of the interval variability between each pulse in a VLF, LF, MF given resolution as was defined above in Heart Rate and HF variability paragraph 1 ECG R-R Ratio between LF HRV power and HF HRV power Freq. Variability LF/HF 1 ECG RRI Wavelet analysis of the interval variability between each Freq. Variability pulse in a given resolution. wavelet analysis 1 ECG alpha Slope of HRV power spectrum Freq. 1 ECG beta Slope of the log of HRV PS Freq. 3 Respi- Upper peak The peaks value, moving average of interval and ratory values, variability of peaks amplitude. The peak represents the average, depth of respiration how deep we take a breath. variability 3 Respi- Lower Peak The lower peaks value, moving average of interval and ratory values, variability of peaks amplitude. The peaks represent the average, depth of breath release. variability 3 Respi- Respiratory The rate is 1/Peak to peak distance. The interval rate, ratory rate, average average rate and variability of the rate and variability 1 Respi- Spectrum Spectrum analysis of the respiratory signal ratory Analysis of the respiratory 1 Respi- Power (area) The area bellow the breath signal ratory 6 PPG PPG Peak An array that represents location and amplitude of Peak and Trough and Trough. Peak denotes a point of maximum blood Amplitude, volume in a finger; Trough denotes a minimum basal blood average and volume. Both amplitude, moving average of the amplitude variability and variability are calculated 1 PPG PPG An array that represents location and amplitude of a point maximum between onset injection and Peak where maximum rate of rate point blood volume increase is observed 1 PPG PPG dicrotic An array that represents location and amplitude of PPG notch dicrotic notch. 12 PPG PP/TT/NN/ Peak to peak, trough to trough, notch to notch, maximum MM/ rate to maximum rate, and other time intervals between intervals, points of interest in PPG beat. Both interval, moving average and average of the interval and variability are calculated-all variability representing the pulse rate 12 PPG /PT/PN/NT/ peak to trough, peak to notch, notch to trough, notch to NM intervals, maximum rate, and other time intervals between points of average and interest in PPG beat. Both interval, moving average of the variability interval and variability are calculated 5 PPG PP spectral Spectrum analysis of the Peak to Peak variability: HF, MF, analysis LF and VLF bands power, LF/HF ration 1 PPG Area Under An array that represents location and integral of single beat Curve of PPG signal (AUC) 1 PPG PPG Time analysis of the envelope of PPG signal. envelope-time (envelope-Peak-Trough of PPG signal) analysis 1 PPG PPG Spectral analysis of the envelope of PPG signal, envelope- (envelope-Peak-Trough of PPG signal) spectral 1 PPG PPG Wavelet analysis of the interval variability between each Variability pulse in a given resolution. wavelet analysis 1 ECG- Respiratory Correlation between the Respiration and the decrease/ Resp sinus increase in R-R interval arrhythmia 1 PPG- Respiratory Correlation between the Respiration and the decrease/ Resp sinus increase in PPG intervals arrhythmia 1 ECG- Pulse An array that represent the location and the delay BP Transition between R peak of ECG signal and Peak of Blood Pressure time signal. (PTT or rPTT) (Weiss, et al. 1980) 1 ECG- Pulse An array that represents the location and the delay PPG Transition between R peak of ECG signal and Peak of PPG time signal (PTT or rPTT). 1 PPG- Pulse An array that represents the location and the delay between PPG Transition two PPG signals located on the same arteriole in different time (PTT or rPTT). 1 CNIBP Average/ Average and variability (moving average and moving variability variability) mean aortic pressure (Pmean) 6 CNIBP CBP Peak, An array that represents location and amplitude of Peak and Trough and Trough. Peak denotes the systolic BP; Trough denotes amplitude, the diastolic. Amplitude, moving average amplitude and average and variability are calculated variability 1 CNIBP Blood onset An array that represents location and amplitude of a point ejection point after Trough where blood ejection is started (maximum second derivative) 1 CNIBP CBP An array that represents location and amplitude of a point maximum between onset injection and Peak where maximum rate of rate point blood volume increase is observed (middle of Anacrotic rise) 1 CNIBP CBP dicrotic An array that represents location and amplitude of CBP notch dicrotic notch. 15 CNIBP PP/PT/PN/ Peak to peak, peak to trough, peak to notch, notch to trough, NT/NM notch to maximum rate, and other time intervals between intervals, points of interest in BP beat. average and variability 1 CNIBP PP spectral Spectrum analysis of the Peak to Peak variability: HF, MF, analysis LF and VLF bands power, LF/HF ration 1 CNIBP Area Under An array that represents location and integral of single beat Curve of PPG signal (AUC) 1 CNIBP BP variability Wavelet analysis of the interval variability between each wavelet pulse in a given resolution. analysis 2 GSR Average/ Average and variability of perspiration (moving average variability and moving variability) Perspiration 1 GSR Peak Interval, The time interval between peaks, the moving average of the average and interval and the variability variability 1 GSR Peak Amplitude, moving average amplitude and variability of amplitude, amplitude of the GSR peaks comparing to the base band average, variability 1 GSR General area The area under each peak 1 GSR Phasic EDA, The first derivative of the GSR signal (EDA phasic), the amplitude moving average of the slopes (normal and absolute values)- average and mean phasic, and the variability of the slopes variability 1 GSR spontaneous The average number of spontaneous fluctuations (SF) in fluctuations an individual Count 1 GSR Spectral The amplitude of the highest peak in the spectrum analysis Analysis: Peak Amplitude 1 GSR Spectral The frequency of the highest peak in the spectrum analysis Analysis: Peak Frequency 1 GSR Spectral The power (integration of signal) in the different frequency Analysis: and specifically in 0.01-0.04 Hz Power 1 GSR difference The differences between the values of the highest peaks in between Peak the spectrum analysis of two different locations Amplitude 1 GSR GSR wavelet Wavelet analysis of the interval variability between each analysis pulse in a given resolution. 2 Temper- Average/ Average and variability of perspiration (moving average ature variability and moving variability) Temperature 1 Temper- Peak Interval, The time interval between peaks, the moving average of ature average and the interval and the variability variability 1 Temper- Peak Amplitude, moving average amplitude and variability of ature amplitude, amplitude of the temperature peaks comparing to the base average, band variability 1 Temper- derivative The first derivative of the temperature signal, the moving ature amplitude average of the slopes (normal and absolute values) and the average and variability of the slopes variability 1 Temper- Spectral The value of the highest peak in the spectrum analysis ature Analysis: Peak Amplitude 1 Temper- Spectral The frequency of the highest peak in the spectrum analysis ature Analysis: Peak Location 1 Temper- Spectral The power (integration of signal) in 0.01-0.04 Hz ature Analysis Power 1 Temper- Temperature Wavelet analysis of the interval variability between each ature wavelet pulse in a given resolution. analysis 2 EOG Average/ variability 4 EEG/ A, , , , Classical EEG frequency band definitions. EMG ratio between Frequency band Frequency range [Hz] the powers delta, 0.5-4-deep sleep (Sometimes is referred as 1-3.5) theta, 4-8-drowsiness (Sometimes is referred as 3.5-8) alpha, 8-14-relaxed but alert (sometimes is referred as 8-13) beta, 14-30-highly alert and focused (sometimes is referred as 13-30) gamma , 30-70-represent binding of different populations of neurons together into a network for the purpose of carrying out a certain cognitive or motor function (sometimes is referred as 36-100) 1 EEG/ Average/ EMG variability 1 EEG/ median/ The frequency at which the median power is reached EMG frequency 1 EEG/ mean/ The frequency at which the average power is reached EMG frequency 1 EEG/ Mean power The average power of the spectrum within epoch EMG 1 EEG/ Peak The frequency at which the power reaches its peak EMG frequency 1 EEG/ Spectral Edge The spontaneous EEG frequency below which x percent EMG Frequency of the power are located. Typically x is in the range 75 to 95. SEF has variously been used to estimate the depth of anesthesia. 1 EEG/ Approximate For details see (Bruhn, Ropcke and Hoeft 2000) EMG Entropy- 1 EEG/ BSR-Burst The burst suppression ratio is the proportion of the EMG Suppression suppression EEG in the analyzed epoch (usually one ratio minute):
[0097] According to some embodiments, the nociception/analgesia monitoring device includes a processor and/or other computing unit. According to some embodiments, the computing unit may be a computing circuity. According to some embodiments, the computing unit may be a remote processing unit such as, but not limited to, a mobile device, smartphone, tablet pc, miniaturized computing device, system on chip, a cloud or the like. According to some embodiments, the nociception/analgesia monitoring device may include an analog to digital (A2D) component. According to some embodiments, the A2D component may be included in the processing unit. According to some embodiments, the A2D component may be included in the (wearable) element attached to the subject, such as the finger probe, the wristwatch, the wristband, the chest band, the glove or the like. According to some embodiments, the A2D component may be included in the sensor. It is understood by one of ordinary skill in the art that inclusion of the A2D component in the wearable element and/or in the sensor may enable a direct transfer of data to remote computing units such as, but not limited to, a cloud. According to some embodiments, the computing unit may be located on or within the finger probe, the wristwatch, the wristband, the chest band, the glove or the like. According to some embodiments, the computing unit may be an external and/or adjunct computing device, such as, but not limited to, a mobile, smartphone, tablet, pc or any dedicated computing device. Each possibility is a separate embodiment. According to some embodiments, the computing unit may be a virtual processor, such as an internet enabled device (i.e. cloud computing).
[0098] According to some embodiments, at least part of the computation may be executed by a computation unit incorporated into the finger probe, the wristwatch, the wristband, the chest band, the glove or the like. According to some embodiments, at least part of the computation may be executed by an external and/or adjunct computing device (mobile, smartphone, tablet, pc or any dedicated computing device). According to some embodiments, at least part of the computation may be executed by a virtual processor. According to some embodiments, the entire computation may be executed by a computation unit incorporated into the finger probe. According to some embodiments, the entire computation may be executed by an external and/or adjunct computing device (mobile, smartphone, tablet, pc or any dedicated computing device). According to some embodiments, the entire computation may be executed by a virtual processor. According to some embodiments, the computation may be executed partially by the computation unit incorporated into the finger probe, the wristwatch, the wristband, the chest band, the glove or the like, partially by the adjunct computing device (mobile, smartphone, tablet, pc or any dedicated computing device) and or partially by a virtual processor.
[0099] According to some embodiments, the processor may be configured to receive the at least three physiological parameters from the at least one sensor, and to compute a nociception scale (NS) value based on an analysis of the at least three parameters and/or features derived therefrom. According to some embodiments, the processor may be configured to receive the at least three physiological parameters from the at least one sensor, and to compute a nociception scale (NS) value based on an integrative analysis of the at least three parameters and/or features derived therefrom.
[0100] According to some embodiments, the term nociception scale (NS) may refer to a multidimensional index of nociception obtained through a non-linear combination of nociception-related physiological parameters. According to some embodiments, the NS has been developed to correlate with a reference clinical score of nociception based on calculated opioid concentration and estimated stimulus strength (i.e., the combined index of stimulus and analgesia or CISA).
[0101] According to some embodiments, the non-linear regression combination of nociception-related physiological parameters may be made using techniques such as Nearest Shrunken Centroids (NSC), Classification and Regression Trees (CART), ID3, C4.5, Multivariate Additive regression splines (MARS), Multiple additive regression trees (MART), Nearest Centroid (NC), Shrunken Centroid Regularized Linear Discriminate and Analysis (SCRLDA), Random Forest, Boosting, Bagging Classifier, Stacking, AdaBoost, RealAdaBoost, LPBoost, TotalBoost, BrownBoost, MadaBoost, LogitBoost, GentleBoost, RobustBoost, bucket of models, ensemble learning algorithms, fuzzy logic, Support Vector Machine (SVM), kernelized SVM, Linear classifier, Quadratic Discriminant Analysis (QDA) classifier, Naive Bayes Classifier and Generalized Likelihood Ratio Test (GLRT) classifier with plug-in parametric or non-parametric class conditional density estimation, k-nearest neighbor, Radial Base Function (RBF) classifier, Multilayer Perceptron classifier, Bayesian Network (BN) classifier, multi-class classifier adapted from binary classifier with one-vs-one majority voting, one-vs-rest, Error Correcting Output Codes, hierarchical multi-class classification, Committee of classifiers, or the like, and any combination thereof. Each possibility is a separate embodiment.
[0102] According to some embodiments, the non-linear regression combination of nociception-related physiological parameters may be made using a random-forest algorithm. According to some embodiments, the non-linear regression combination of nociception-related physiological parameters may be made using a boosting framework and/or ensemble learning algorithms.
[0103] According to some embodiments, the term NS value may refer to a nociception value obtained for a specific patient, having reference to the NS index. According to some embodiments, the NS value is essentially unaffected by physiological changes resulting from administration of an anesthetic and/or analgesic and not from nociception. That is, administration of an anesthetic and/or administration of analgesic, in the absence of pain, does not cause significant changes in the computed NS value. As used herein, the term essentially with regards to an unaffected NS value may refer to an NS value which does not qualitatively change the assessment of the patient's nociception level. It is thus understood that the NS value is reflective of nociception per se and is not affected by changes in physiological parameters resulting from drug administration According to some embodiments, an essentially unchanged NS value may include small numerical changes in the NS value as a result of drug administration. According to some embodiments, an essentially unchanged NS value may include a less than 10 unit, less than a 5 unit, or less than a 2 unit change in the NS value as a result of drug administration, out of a 0-100 numerical scale. Each possibility is a separate embodiment.
[0104] According to some embodiments, the computing unit may be configured to filter and/or level out side effects and/or physiological changes (e.g. bradycardia and/or vasodilation) caused by administration of a medicament. According to some embodiments, computing the NS value may include leveling out physiological changes caused by drugs. As used herein, the term level out may refer to computing the NS value while taking into account a sufficient amount of parameters and or features derived therefrom in order for the NS value to be essentially unaffected by the physiological changes. According to some embodiments, computing the NS value may include filtering out physiological changes caused by medicaments independently of nociception. According to some embodiments, computing the NS value may include providing lower weights to parameters known to change as a result of drug administration. As a non-limiting example, heart rate related parameters and/or features derived therefrom may receive lower weights when the patient is administered remifentanil known to cause bradycardia. As another non-limiting example, photoplethysmogram related parameters and/or features derived therefrom may receive lower weights when the patient is administered propofol known to have vasodilating effects.
[0105] According to some embodiments, when the NS value crosses a predefined threshold value nociception is identified. According to some embodiments, when the NS value crosses a first predefined threshold value a mild nociception level is identified. According to some embodiments, when the NS value crosses a second predefined threshold value a moderate nociception level is identified. According to some embodiments, when the NS value crosses a third predefined threshold value a severe nociception level is identified.
[0106] According to some embodiments, the NS value enables differentiation between no nociception and nociception with a sensitivity of above 70% at a specificity of at least 70%. According to some embodiments, the NS value enables differentiation between no nociception, mild nociception, moderate nociception and/or severe nociception with a sensitivity of above 70% at a specificity of at least 70%. According to some embodiments, the NS value enables differentiation between no nociception, and severe nociception with a sensitivity of above 70% at a specificity of at least 70%. According to some embodiments, the NS value enables differentiation between no nociception and moderate nociception with a sensitivity of above 70% at a specificity of at least 70%. According to some embodiments, the NS value enables differentiation between no nociception and mild nociception with a sensitivity of above 70% at a specificity of at least 70%. According to some embodiments, the NS value enables differentiation between mild nociception and severe nociception with a sensitivity of above 70% at a specificity of at least 70%. According to some embodiments, the NS value enables differentiation between mild nociception and moderate nociception with a sensitivity of above 70% at a specificity of at least 70%. According to some embodiments, the NS value enables differentiation between moderate nociception and severe nociception with a sensitivity of above 70% at a specificity of at least 70%.
[0107] According to some embodiments, the NS value enables differentiation between no nociception and nociception with a sensitivity of above 70% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception, mild nociception, moderate nociception and/or severe nociception with a sensitivity of above 70% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception, and severe nociception with a sensitivity of above 70% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception and moderate nociception with a sensitivity of above 70% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception and mild nociception with a sensitivity of above 70% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between mild nociception and severe nociception with a sensitivity of above 70% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between mild nociception and moderate nociception with a sensitivity of above 70% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between moderate nociception and severe nociception with a sensitivity of above 70% at a specificity of at least 75%.
[0108] According to some embodiments, the NS value enables differentiation between no nociception and nociception with a sensitivity of above 75% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception, mild nociception, moderate nociception and/or severe nociception with a sensitivity of above 75% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception, and severe nociception with a sensitivity of above 75% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception and moderate nociception with a sensitivity of above 75% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception and mild nociception with a sensitivity of above 75% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between mild nociception and severe nociception with a sensitivity of above 75% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between mild nociception and moderate nociception with a sensitivity of above 75% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between moderate nociception and severe nociception with a sensitivity of above 75% at a specificity of at least 75%.
[0109] According to some embodiments, the NS value enables differentiation between no nociception and nociception with a sensitivity of above 80% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception, mild nociception, moderate nociception and/or severe nociception with a sensitivity of above 80% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception, and severe nociception with a sensitivity of above 80% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception and moderate nociception with a sensitivity of above 80% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception and mild nociception with a sensitivity of above 80% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between mild nociception and severe nociception with a sensitivity of above 80% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between mild nociception and moderate nociception with a sensitivity of above 80% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between moderate nociception and severe nociception with a sensitivity of above 80% at a specificity of at least 75%.
[0110] According to some embodiments, the NS value enables differentiation between no nociception and nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception, mild nociception, moderate nociception and/or severe nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception, and severe nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception and moderate nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception and mild nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between mild nociception and severe nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between mild nociception and moderate nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between moderate nociception and severe nociception with a sensitivity of above 85% at a specificity of at least 75%.
[0111] According to some embodiments, the NS value enables differentiation between no nociception and nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception, mild nociception, moderate nociception and/or severe nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception, and severe nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception and moderate nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception and mild nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between mild nociception and severe nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between mild nociception and moderate nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between moderate nociception and severe nociception with a sensitivity of above 85% at a specificity of at least 75%. According to some embodiments, the NS value enables differentiation between no nociception and severe nociception with a sensitivity of above 80% at a specificity of at least 84%. According to some embodiments, the NS value enables differentiation between mild nociception and severe nociception with a sensitivity of above 80% at a specificity of at least 84%. According to some embodiments, the NS value enables differentiation between no nociception, and nociception with a sensitivity of above 80% at a specificity of at least 84%. According to some embodiments, the NS value enables differentiation between no nociception and mild nociception with a sensitivity of above 80% at a specificity of at least 84%. According to some embodiments, the NS value enables differentiation between no nociception and severe nociception with a sensitivity of above 80% at a specificity of at least 84%. According to some embodiments, the NS value enables differentiation between mild nociception and severe nociception with a sensitivity of above 80% at a specificity of at least 84%.
[0112] According to some embodiments, the NS value enables differentiation between no nociception and severe nociception with a sensitivity of above 85% at a specificity of at least 84%. According to some embodiments, the NS value enables differentiation between mild nociception and severe nociception with a sensitivity of above 85% at a specificity of at least 84%. According to some embodiments, the NS value enables differentiation between no nociception, and nociception with a sensitivity of above 85% at a specificity of at least 84%. According to some embodiments, the NS value enables differentiation between no nociception and mild nociception with a sensitivity of above 85% at a specificity of at least 84%. According to some embodiments, the NS value enables differentiation between no nociception and severe nociception with a sensitivity of above 85% at a specificity of at least 84%. According to some embodiments, the NS value enables differentiation between mild nociception and severe nociception with a sensitivity of above 85% at a specificity of at least 84%.
[0113] According to some embodiments, the NS value computed for the patient may enable determining the amount and/or type of an analgesic required to reduce the NS value below a predetermined threshold value. According to some embodiments, the NS value computed for the patient may enable determining the amount and/or type of an analgesic required to maintain nociception levels within a desired target range. According to some embodiments, the NS value may trigger an output signal.
[0114] According to some embodiments, the output signal may include triggering an alarm and/or alert. According to some embodiments, the alarm and/or alert may be visual, audible, and/or physical. Each possibility is a separate embodiment. Non-limiting examples of visual alarms/alerts include a flashing light, a displayed message and/or icon and the like. Each possibility is a separate embodiment. According to some embodiments, the output may be visual, audio, tactile, virtual reality or otherwise noticeable. Non-limiting examples of audible alarms/alerts include a sound, a vocal instruction and the like. Each possibility is a separate embodiment. Non-limiting examples of physical alarms/alerts include vibration, shaking and the like. Each possibility is a separate embodiment. According to some embodiments, a different alarm (e.g. different sound, frequency, intensity or type of alarm/alert) may be triggered when the NS value crosses a first threshold value indicative of a first level of nociception (e.g. mild nociception) as compared to when the NS value crosses a second threshold value indicative of a second level of nociception (e.g. severe nociception). As a non-limiting example, when the NS value crosses the first threshold value a written message may be displayed whereas when the NS value crosses the second threshold value an audial alarm may be triggered. As another non-limiting example, when the NS value crosses the first threshold value an audial alarm at a first intensity may be triggered whereas when the NS value crosses the second threshold value the audial alarm may be triggered at a second intensity (e.g. louder).
[0115] According to some embodiments, the output signal may include displaying a written recommendation, for example, a recommendation suggesting that a change in nociception/analgesia management is required. According to some embodiments, the display may be visual, audio, tactile, virtual reality or otherwise noticeable. As a non-limiting example, an NS value representing mild nociception may trigger an output signal suggesting that a moderate increase in analgesic is needed, whereas an NS value indicating that the patient is suffering from severe pain may trigger an output signal indicating that a significant change in analgesic (type and/or amount) is needed. According to some embodiments, the output signal may trigger automatic adjustment of an analgesic dose. For example, an NS value below (or abovedepending on the scale) a predetermined threshold may automatically trigger a reduction in the dose of the analgesic administered, whereas an NS value above (or belowdepending on the scale) may automatically trigger an increase in the dose of the analgesic administered.
[0116] According to some embodiments, there is provided a method for determining a nociception level of a subject, the method including receiving at least three monitored physiological parameters of the patient and computing a nociception scale (NS) value based on an analysis of the at least three parameters and/or features derived therefrom. According to some embodiments, the analysis may include an integrative analysis of the at least three parameters and/or features derived therefrom. According to some embodiments, the method may include leveling out changes in physiological parameters caused by administration of drugs rather than nociception. As a non-limiting example, the method may include, directly or indirectly, leveling out changes in heart rate related parameters caused due to a drug's (e.g. remifentanil) bradycardial effect. According to some embodiments, when the NS value crosses a first predefined threshold value a mild nociception level is identified; and when the NS value crosses a second predefined threshold value a severe nociception level is identified. According to some embodiments, the method further includes triggering an alarm when the NS value crosses the first and/or second predefined threshold value, as essentially described herein.
[0117] According to some embodiments, there is provided a computer implemented software configured to determine a nociception level of a subject. According to some embodiments, the software may be configured to receive at least three monitored physiological parameters from at least one functionally connected sensor and to compute a nociception scale (NS) value based on an analysis of the at least three parameters and/or features derived therefrom. According to some embodiments, the analysis may include an integrative analysis of the at least three parameters and/or features derived therefrom. According to some embodiments, the software may be further configured to level out changes in physiological parameters caused by administration of drugs in a manner independent of nociception. As a non-limiting example, the software may be configured to, directly or indirectly, level out changes in plethysmography (PPG) related parameters caused due to a drug's (e.g. remifentanil) bradycardial effect and not due to changes in nociception. According to some embodiments, the software may be configured to trigger an alarm when the NS value crosses the first and/or second predefined threshold value, as essentially described herein.
[0118] According to some embodiments, there is provided a device for determining analgesic efficacy. According to some embodiments, the device includes at least one sensors configured to sense at least three parameters of a patient. According to some embodiments, the at least three parameters may be sensed before (A0) and after (A1) administration of an analgesic and before (S0) and after (S1) providing a noxious stimulus. It is understood to one of ordinary skill in the art that some measurements may represent combinations of A0, A1, S0 or S1. For example, A0 and S0 may be obtained from a measurement made before administration of the analgesic and before the noxious stimulus has been provided. Similarly, A0 and S1 may be obtained from a measurement made before administering a drug but after providing the noxious stimulus. For example, A1 and S0 may be obtained from a measurement made after administration of the analgesic but before the noxious stimulus; and A1 and S1 may be obtained from a measurement made after administration of the analgesic and after the noxious stimulus. It is further understood that the at least three parameters may be sensed before and after administering additional doses of analgesics (A2, A3 . . . An) and/or before and after providing additional noxious stimuli (S2, S3 . . . Sn).
[0119] As a non-limiting example, the at least three parameters may be sensed at a first time point t.sub.0, prior to administration of the analgesic and prior to providing a stimulus. At time point t.sub.1, an analgesic may be administered followed by a second measurement of the at least three parameters. It is understood by one of ordinary skill in the art that the time window between administration of the analgesic and the measurement of the at least three parameters may vary depending on the type of analgesic administered and may thus be determined accordingly. At time point t.sub.2, a noxious stimulus may be provided followed by a third measurement of the at least three parameters, typically simultaneously with or immediately after the stimulus.
[0120] As another non-limiting example, the at least three parameters may be sensed at a first time point t.sub.0, prior to administration of the analgesic and prior to providing a stimulus. At time point t.sub.1, a noxious stimulus may be provided followed by a second measurement of the at least three parameters, typically simultaneously with or immediately after the stimulus. At time point t.sub.2, an analgesic may be administered followed by a third measurement of the at least three parameters and, at time point t.sub.3, a second noxious stimulus may be provided followed by a third measurement of the at least three parameters, again typically either simultaneously with or immediately after the stimulus.
[0121] According to some embodiments, the device further includes a computing unit adapted to receive the at least three parameters from the at least one sensor obtained for A0, A1, S0 and S1 and/or combinations thereof. According to some embodiments, the computing unit is further configured to compute nociception scale (NS) values for A0, A1, S0 and S1 and/or combinations thereof based on an analysis of the at least three parameters and/or features derived therefrom. According to some embodiments, the analysis may include an integrative analysis of the at least three parameters and/or features derived therefrom.
[0122] According to some embodiments, the computing unit is further configured to determine the efficacy of the analgesic based on a comparison of the NS values obtained for A0, A1, S0 and S1 and/or combinations thereof. It is understood to one of ordinary skill in the art that in order for an analgesic to be considered efficient, the NS values obtained before administration of the analgesic and before the noxious stimulus (A0S0) should be unchanged or only mildly elevated after administration of the analgesic and after the noxious stimulus (A1S1). According to some embodiments, in order for an analgesic to be considered efficient, the change in the NS value between A0S0 and A1S1 should be less than 10 units out of a 0-100 numerical scale. According to some embodiments, in order for an analgesic to be considered efficient, the change in the NS value between A0S0 and A1S1 should be less than 5 units out of a 0-100 numerical scale. According to some embodiments, in order for an analgesic to be considered efficient, the change in the NS value between A0S0 and A1S1 should be less than 2 units out of a 0-100 numerical scale. According to some embodiments, in order for an analgesic to be considered efficient, the change in the NS value between A0S0 and A1S1 should be less than 1 unit out of a 0-100 numerical scale.
[0123] According to some embodiments, the noxious stimulus in absence of an analgesic (A0S1) may cause an at least 10 unit increase in the NS value out of a 0-100 numerical scale, as compared to before the noxious stimulus (A0S0). According to some embodiments, the noxious stimulus in absence of an analgesic (A0S1) may cause an at least 15 unit increase in the NS value out of a 0-100 numerical scale, as compared to before the noxious stimulus (A0S0). According to some embodiments, the noxious stimulus in absence of an analgesic (A0S1) may cause an at least 20 unit increase in the NS value out of a 0-100 numerical scale, as compared to before the noxious stimulus (A0S0). According to some embodiments, the noxious stimulus in absence of an analgesic (A0S0) may cause an at least 30 unit increase in the NS value out of a 0-100 numerical scale, as compared to before the noxious stimulus (A0S0), as compared to before the noxious stimulus (A0S0).
[0124] According to some embodiments, administration of the analgesic, in the absence of a noxious stimulus (A1S0), causes essentially no change in the NS value as compared to before the administration of the analgesic (A0S0). According to some embodiments, administration of the analgesic in the absence of a noxious stimulus (A1S0) causes essentially no change in the NS value as compared to before the administration of the analgesic (A0S0), such as less than 10 units, 5 units, 2 units or 1 units change in the NS value out of a 0-100 numerical scale. Each possibility is a separate embodiment.
[0125] According to some embodiments, the noxious stimulus may include tetanic stimulus, thermal (heat or cold) stimulus, pressure stimulus, touch (tickle, itch, crude, flutter, pressure) stimulus, electric stimulus, mechanical stimulus, proprioception stimulus, chemical stimulus or combinations thereof. Each possibility is a separate embodiment.
[0126] According to additional or alternative embodiments, the device may be configured to determine an efficient dose of an analgesic.
[0127] According to some embodiments, when determining an efficient dose of an analgesic, the at least three parameters may be sensed before and after administration of at least one dose of an analgesic and/or before and after providing a noxious stimulus.
[0128] According to some embodiments, when determining an efficient dose of an analgesic, the at least three parameters may be sensed before (A0) administration of an analgesic, after a first dose of an analgesic (A1) and after a second dose of an analgesic (A2) before (S0) and after (S1) providing a noxious stimulus. It is understood to one of ordinary skill in the art that some measurements may represent combinations of A0, A1, A2, S1 or S2, as essentially described above. It is further understood that any suitable number of doses may be tested and that the first and second doses are illustrative only.
[0129] According to some embodiments, in order for a dose to be considered efficient, the change in the NS value between A0S0and A1S1 or A2S1 should be less than 10 units, less than 5 units, less than 2 units or less than 1 units. Each possibility is a separate embodiment.
[0130] According to some embodiments, in order for a dose of an analgesic to be considered efficient, the NS value before and after a noxious stimuli should be essentially unchanged (i.e. enough to avoid nociception caused by the stimuli), while the NS value of a lower dose causes changes in the NS value, i.e. the dose is the lowest possible dose required to avoid nociception. According to some embodiments, in order for a dose to be considered efficient, the change in the NS value between A0S0 and A2S1 should be less than 10 units, less than 5 units, less than 2 units or less than 1 units, whereas the change in the NS value between A0S0 and A1S1 is larger than 1 unit, 2 units, 5 units 10 units, 20 units or 30 units. Each possibility and/or combination are separate embodiments.
[0131] According to some embodiments, there is provided a method for determining efficacy of an analgesic, the method including receiving at least three monitored physiological parameters before (A0) and after (A1) administration of an analgesic and before (S0) and after (S1) providing a noxious stimulus, computing nociception scale (NS) values for A0, A1, S0 and S1 and/or combinations thereof based on an analysis of the at least three parameters and/or features derived therefrom and determining the efficacy of the analgesic based on a comparison of the NS values obtained for A0, A1, S0 and S1 and/or combinations thereof, as essentially described herein. According to some embodiments, the analysis may include an integrative analysis.
[0132] According to some embodiments, there is provided a computer implemented software configured to determine efficacy of an analgesic. According to some embodiments, the software may be configured to receive at least three physiological parameters monitored before (A0) and after (A1) administration of an analgesic and before (S0) and after (S1) providing a noxious stimulus to compute a nociception scale (NS) value for A0, A1, S0 and S1 and/or combinations thereof and to determine the efficacy of the analgesic based on a comparison of the NS values obtained for A0, A1, S0 and S1 and/or combinations thereof, as essentially described herein.
[0133] According to some embodiments, there is provided a method for determining an optimal dose of an analgesic, the method including receiving at least three monitored physiological parameters before (A0) administration of an analgesic and after administration of a first (A1) and a second (A2) dose of an analgesic and before and after (S0) and after (S1) providing a noxious stimulus, computing nociception scale (NS) values for A0, A1, A2, S0 and S1 and/or combinations thereof based on an analysis of the at least three parameters and/or features derived therefrom and determining the optimal dose of the analgesic based on a comparison of the NS values obtained for A0, A1, A2, S0 and S1 and/or combinations thereof, as essentially described herein. According to some embodiments, the analysis may include an integrative analysis.
[0134] According to some embodiments, there is provided a computer implemented software configured to determine an optimal dose of an analgesic. According to some embodiments, the software may be configured to receive at least three physiological parameters monitored before (A0) administration of an analgesic and after administration of at least a first (A1) and a second (A2) dose of an analgesic and before (S0) and after (S1) providing at least one noxious stimulus, to compute a nociception scale (NS) value for A0, A1, A2, S0 and S1 and/or combinations thereof and to determine the optimal dose of the analgesic based on a comparison of the NS values obtained for A0, A1, A2, S0 and S1 and/or combinations thereof, as essentially described herein.
[0135] According to some embodiments, there is provided a computer implemented software configured to determine an optimal dose of an analgesic. According to some embodiments, the software may be configured to receive at least three physiological parameters monitored before and after administration of at least one dose of an analgesic and/or before and after providing at least one noxious stimulus, to compute corresponding nociception scale (NS) values and to determine the optimal dose of the analgesic based on the NS values obtained, as essentially described herein.
[0136] According to some embodiments, determining an optimal dose of an analgesic includes determining a nociception profile of the patient. According to some embodiments, the optimal dose of an analgesic may be customized to the specific patient.
[0137] According to some embodiments, there is provided a method for determining a nociception profile of a patient. According to some embodiments, the method may include computing a baseline nociception scale (NS) value of the patient, providing a first noxious stimuli to a patient, computing a first nociception scale (NS) value in response to the first noxious stimuli, providing a first dose of an analgesic to the patient, providing a second noxious stimuli to a patient, and computing a second nociception scale (NS) value in response to the second noxious stimuli. According to some embodiments, the first and second noxious stimuli may be identical. According to some embodiments, the first and second noxious stimuli may be different (e.g. different intensity and/or different type of stimuli). It is understood by one of ordinary skill in the art, that the method may include providing additional stimuli and/or additional doses of analgesic, thereby enhancing the resolution of the patient's nociception profile.
[0138] According to some embodiments, the operation of the stimulator (e.g. an electrical, thermal, mechanical, or other stimulator) may be automated and controlled by an internal or external processing unit. According to some embodiments, adjustments in the noxious stimulus provided (e.g. changes in the type of stimulus, and or changes in the length and/or frequency of a stimulus) may be automated. For example, the operation and/or changes in operation of the stimulator may be based on input signals automatically received by the processing unit. For example, the operation and or changes in operation of the stimulator may be based on a predefined operation program encoded into the stimulator. Additionally or alternatively, the dosages of analgesics may be automatically provided and/or adjusted based on control signals sent to an infusion pump providing the analgesic dosages to the patient. Before explaining at least one embodiment in detail, it is to be understood that aspects of the embodiments are not necessarily limited in their application to the details of construction and the arrangement of the components and/or methods set forth herein. Some embodiments may be practiced or carried out in various ways. The phraseology and terminology employed herein are for descriptive purposes and should not be regarded as limiting.
[0139] Reference is now made to
[0140] Reference is now made to
[0141] Reference is now made to
[0142] Reference is now made to
[0143] Reference is now made to
[0144] Reference is now made to
[0145] The following examples are presented in order to more fully illustrate some embodiments of the invention. They should, in no way be construed, however, as limiting the broad scope of the invention.
EXAMPLES
Example 1
Clinical Study #1
Ethics
[0146] The protocol was performed after approval was obtained from the local Human Ethics Committee (Commissie Medische Ethiek, Leiden University Medical Center, 2300 RC Leiden, The Netherlands) and was registered at www.clinicaltrials.gov under number NCT01912118. All patients gave oral and written informed consent before enrollment into the study. The study was performed from July 2013 to June 2014.
Patients
[0147] American Society of Anesthesiology class I, II or III patients (aged 18-80 years) of either sex, scheduled for elective surgery under general anesthesia, were recruited to participate in the study. Exclusion criteria included: inability to give informed consent, pregnancy or lactation, body mass index >35 kg/m2, perceived difficult intubation, planned rapid sequence intubation and use of beta-adrenergic receptor antagonists. Preoperative preparation was according to local protocol.
Study Design
[0148] In this prospective randomized study, patients received total intravenous anesthesia with propofol and remifentanil. Seventy-two patients were randomly assigned to one of six possible remifentanil target concentrations: 0 (propofol only, n=12), 1, (n=12), 2 (n=12), 3 (n=12), 4 (n=12) and 5 (n =12) ng/mL using a custom built remifentanil target controlled infusion pump (Remifusor, University of Glasgow, United Kingdom) programmed with the remifentanil pharmacokinetic data set published by Minto et al. Similarly, propofol was infused using a target controlled infusion system (Orchestra Base Primea, Fresenius Kabi, Zeist, The Netherlands) programmed with the propofol pharmacokinetic set of Marsh et al. The target was adapted such that prior to intubation or skin incision the bispectral index (BIS) of the electroencephalogram (BIS VISTA, Covidien, Dublin, Ireland) was maintained at 455 for at least 10-15 min. If needed a muscle relaxant (rocuronium 0.5 mg/kg) could be administered prior to intubation.
Data Collection
[0149] A finger probe containing a plethysmography (PPG) sensor, a galvanic skin response (GSR) sensor, skin temperature sensor and a 3-axis accelerometer was placed on the index finger of the subject's right hand (Medasense Biometrics, Ramat Yishai, Israel).
[0150] The signals from the probe were sampled at 50 Hz and recorded on a laptop and processed off-line using MatlabR2011b software (TheMathworks Inc., Natick, Mass.). The following variables were calculated from the finger probe heart rate (HR), heart rate variability (HRV), plethysmograph wave amplitude (PPGA), skin conductance level (SCL), and fluctuations in skin conductance and their derivatives. To measure the non-invasive beat-to-beat blood pressure, an appropriately sized finger cuff was applied to the mid-phalanx of the left index finger, which was connected to a Nexfin monitor (Edwards Lifesciences, Irvine, Calif.). See Ref. Martina et al. for an elaborate explanation of the Nexfin system and calculation of blood pressure. The beat-to-beat finger blood pressure was stored on disc for off-line analysis. Data were collected from the time of induction of anesthesia until approximately 3-5 minutes after incision. Specific events occurring during the study (start of induction, patient movement, intubation, incision) were logged to enable a direct link between stimulus and measurements.
[0151] Description of the Nociception Scale (NS)
[0152] The NS is based on a non-linear combination of nociception-related physiological parameters: heart rate (HR), heart rate variability (HRV at the 0.15-0.4 Hz band power), amplitude of the photo-plethysmograph wave (PPGA), skin conductance level (SCL), number of skin conductance fluctuations (NSCF), and their time derivatives. The NS was developed to correlate with a reference clinical score of nociception based on estimated opioid concentration and stimulus. A composite parameter was derived using a non-linear regression method, in which the physiological signals with their derivatives were used as predictor variables and the combined estimated opioid concentration and stimulus were used as the observed variable for the non-linear regression models. The estimated multiparameter composite derived from the regression analyses was scaled from 0 to 100 to produce the NS.
Data Analysis
[0153] The sample size was set to include 12 subjects per remifentanil treatment level i.e. 72 patients in total. Statistical and data analyses were performed using Matlab R2011b scientific software (The Mathworks Inc., Natick, Mass.). Three distinct stimuli were defined in each patient: a non-noxious event, incision (moderate noxious stimuli) and intubation (severe noxious stimuli). A non-noxious event was defined as a 1-min interval within a 5-min window of absence of noxious stimulation; intubation was defined as the time interval around the insertion of the orolaryngeal tube into the trachea and included the preceding laryngoscopy; incision was defined as the time interval around the surgical skin incision. For each stimulus, two parameter values were defined, one prior to stimulation (before) and one after stimulation (after), which were the average of data before and after the stimulus along a certain time interval. These time intervals were for the non-noxious stimulus the first (before) and last (after) 30 s of the 1-min non-noxious interval, for incision and intubation the 30-60 s prior to the stimulus (before) and the 10-180 s following the stimulus (after).
Statistical Analysis
[0154] 3 pain assessment indices were compared, namely NS, mean arterial blood pressure (MAP) and heart rate (HR). The following statistical tests were performed to compare the performance of NS, NS, MAP, MAP, HR and HR:
[0155] 1. Right-tailed paired t-test to assess whether the average reaction () of the three indices to stimulation are significantly greater than zero. Two-tailed unpaired t-test to assess whether the population values of the variables after stimulation were significantly different from values obtained before stimulation. Additionally the effect of stimulation on BIS was tested using paired and unpaired t-tests.
[0156] 2. Receiver operating characteristic (ROC) curves were constructed to assess the ability of the individual variables (absolute values and ) to discriminate between noxious and non-noxious events. Confidence intervals of the area-under-the-curves (AUC) were calculated using the method of Hanley and McNeil, which corrects for the use of correlated data.
[0157] 3. Repeated analysis of variance (RM-NOVA) to test the ability of each of the variables to grade noxious stimuli, i.e. to assess whether the variable values increased with an increasing stimulus strength: non-noxious stimulus<moderate noxious stimulus (incision)<intense noxious stimulus (intubation). In case of a significant main effect, a Scheffe's post-hoc multiple comparison test was applied to test between pairs non- noxious stimulus vs. intubation, non-noxious stimulus vs. incision and incision vs. intubation.
[0158] 4. For non-noxious stimuli and intubation, the Spearman correlation coefficient was calculated to quantify the relation between HR, MAP, NS and the remifentanil target concentration. This was done separately for time intervals before and after. A quadratic polynomial was fitted by least square analysis to the data. Values are presented as mean SD or mean (95% confidence interval, CI) unless otherwise indicated; p-values <0.05 were considered significant.
Results
[0159] Seventy-two patients participated in the study, as described. The data from 71 patients were used in the analysis. All patients completed the study without side effects. In about half of the patients, a muscle relaxant was administered before intubation. Prior to noxious stimulation (intubation/skin incision) BIS values were on average 45.09.0 (meanSD), 45.69.9, 47.29.1, 42.67.4, 44.78.0 and 47.09.8 in the 0, 1, 2, 3, 4 and 5 ng/mL remifentanil groups, respectively (RM-ANOVA: p>0.05; grand mean 45.58.8).
Response to Noxious Events
[0160] The effect of non-noxious stimuli, incision and intubation on BIS, HR, MAP and NS are given in
[0161] Incision had no effect on BIS and HR but caused increases in MAP and NS although, in contrast to MAP, the effects on NS were significant in both paired and unpaired t-tests: BIS 0.92 (1.2 to 3.3; ns), HR 1.3 (0.46 to 3.1; ns) min1, MAP 7.9 (1.9 to 13.0; paired t-test: p<0.001; unpaired t-test ns) mmHg and NS 8.0 (0.4 to 16.0; paired t-test: p<0.001; unpaired t-test p<0.001).
[0162] Comparing the three different stimuli, a significant pain response observed for HR, MAP and NS after (but not before) stimulation and A's: HR F(2,96)=9.4, p<0.001; HR F(2,96)=27, p<0.0001); MAP F(2,80)=28, p<0.001; MAP F(2,80)=19, p<0.0001; NDI F(2,96)=23, p<0.0001; NS F(2,96)=46, p<0.0001.
[0163] Post-hoc analysis showed that only NS (after stimulation) and NS graded the level of noxious intensity with non-noxious NS<incision NS<intubation NS. HR after stimulation and HR could not differentiate between non-noxious stimuli and incision (p=0.24). MAP could not discriminate between incision and intubation (p=0.07).
[0164] The ROC curves were calculated (n=71) for HR, MAP and NS (all after stimulation) and HR, MAP and NS and are shown in FIG. 7 and FIG. 8. ROC area-under the curve (AUC) sensitivity values at a specificity of 75% are shown in Table 2.
TABLE-US-00002 TABLE 2 ROC-AUC, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the NS, NS, HR, HR, MAP and MAP at a specificity of 75%. Variable AUC* Sensitivity Specificity PPV NPV HR 0.66 (0.56-0.75) 63% 75% 72% 65% MAP 0.73 (0.64-0.81) 63% 75% 75% 64% NS .sup.0.82 (0.75-0.89).sup. 73% 75% 75% 72% HR 0.84 (0.77-0.91) 84% 75% 78% 81% MAP 0.78 (0.70-0.86) 75% 75% 78% 72% NS 0.95 (0.91-99).sup.# 94% 75% 80% 92% Random 0.50 25% 75% 50% 50% classifier NS, MAP and HR given were obtained after noxious stimulation. *In parentheses the 95% confidence interval. .sup.p = 0.001 vs. HR; p = 0.036 vs. MAP. .sup.#p = 0.0003 vs. HR; p < 0.001 vs. MAP; p = 0.0001 vs. NS; p < 0.0001 vs. HR; p < 0.0001 vs. MAP.
[0165] NS outperformed all other variables in its ability to discriminate between noxious (intubation or incision) and non-noxious events with an AUC of 0.95 (95% CI 0.91 to 0.99). The NS AUC was significantly larger compared to all other variables (p=0.0003 vs. HR; p<0.0001 vs. MAP; p<0.0001 vs. HR; p=0.00004 vs. MAP). Moreover, NS after stimulation outperformed MAP and HR in classifying noxious stimuli (AUC 0.82, 95% CI 0.75 to 0.89, p=0.001 vs. HR; p=0.035 vs MAP). The NS outperformed HR and MAP and NS outperformed HR and MAP in terms of sensitivity, specificity and positive and negative predictive values for the detection of noxious stimuli (Table 1). For NS a cut-off value between noxious and non-noxious stimuli of 16 yielded a specificity and sensitivity of 80% and 73%.
[0166] These results show that NS can characterize the degree of pain experienced by a subject objectively as well as differentiate between different levels of pain.
Response to Intubation Under Different Remifentanil Target Concentrations
[0167] The effects of increasing concentrations of remifentanil on HR (n=57), MAP (n=50) and NS (n=57) before and after noxious stimulation are shown in FIG. 9 to FIG. 11. The NS before and after non-noxious stimulation showed no significant correlation to the remifentanil concentration (rS=0.047 and 0.024, p>0.05;
Example 2
Clinical Study #2
Ethics
[0168] This study was executed in accordance with the Declaration of Helsinki, in agreement with the guidelines for conducting a clinical investigation set forth in ISO 14155. Additionally, Israel-specific laws and regulations concerning the conduct of clinical studies with medical devices were followed.
[0169] The study was approved by the institutional review board (IRB) (IRB number: #0326-12) and amendments were reviewed and approved by the IRB and was commenced only after the approvals from the IRB were obtained. All requirements imposed by the IRB or regulatory authorities were followed.
[0170] Subjects were informed by the investigator of the possible benefits, risks, and outcomes of the use of the device. All subjects who were potential study candidates provided written signed and dated informed consent. The subjects received a signed copy of the informed consent form; the original was filed in the investigational site file.
Description of the Device and the Nociception Scale (NS)
[0171] The monitoring device includes a proprietary console and a finger probe. The console is connected to a PC that runs a user interface. The finger probe contains sensors acquiring the photo-plethysmogram (PPG), galvanic skin response (GSR), skin temperature, and a 3-axis accelerometer. By analyzing the recorded signals, the nociception scale is computed. The recorded signals and parameter trends, including the NS, are displayed on the user interface.
[0172] The NS is based on a non-linear combination of nociception-related physiological parametersheart rate (HR), heart rate variability (HRV, at the 0.15-0.4 Hz band power), photo-plethysmograph wave amplitude (PPGA), skin conductance level (SCL), number of skin conductance fluctuations (NSCF), and their time derivatives. The NS was developed to correlate with a reference clinical score of nociception based on calculated opioid concentration and estimated stimulus strength (i.e., the combined index of stimulus and analgesia or CISA). A composite parameter was derived from Random Forest analysis, a non-linear regression method, in which the physiological signals with their derivatives were used as predictor variables and the CISA was used as the observed variable for the non-linear regression models. The estimated multi-parameter composite derived from the regression analyses was scaled from 0 to 100 to produce the NS.
Selection of Study Population
[0173] Subjects were chosen according to the following criteria: Inclusion criteria: signed written informed consent, age 18-75 years, ASA physical status 1-3, elective surgery under general anesthesia. Exclusion criteria: pregnancy or lactation, history of severe cardiac arrhythmias, presence of neuromuscular disease, abuse of alcohol or illicit drugs, history of mental retardation, dementia, psychiatric disorders, allergy to the anesthetic drugs included in study protocol.
Study Design and Plan
[0174] The first part of the study was applied on all recruited subjects and was designed as within subject comparisons in different set-ups. The first set-up included a comparison of subjects' response to two identical experimental tetanic stimulations; the first with no analgesics and the second following a single bolus of opioids (active treatment self-control). The second set-up included comparison of subjects' response to two noxious clinical stimuli (intubation and first skin incision/trocar insertion) using a non-noxious period as reference. The second part of the study was designed to compare subjects' response to first skin incision/trocar insertion at two levels of Remifentanil. Subjects were randomized into one of two groups after intubation (dose comparison concurrent control; Randomized, double-blind).
Brief Description of Procedure
[0175] Subjects were randomized (equal distribution) to one of two groups of Remifentanil TCI (2 ng/ml or 4 ng/ml) base level. Randomization was performed using Matlab software. Remifentanil infusion was started after the time point of intubation.
[0176] In the operating room, subjects were connected to a standard subject monitor (CARESCAPE B650 GE healthcare, Helsinki, Finland (including ECG, NIBP, SPO.sub.2, End Tidal CO.sub.2, Surgical Pleth Index (SPI), and Entropy modules; and to the monitoring device disclosed herein.
[0177] Standard anesthesia protocol was used: [0178] a. After 1 mg bolus of midazolam, anesthesia was induced by incremental boluses of 50 mg propofol until subject clinically lost consciousness, and entropy (SE) dropped below 60. Before intubation 2 g/kg fentanyl and 1 mg/kg rocuronium were administered. [0179] b. After the time point of intubation, for the maintenance of analgesia throughout surgery, subjects were randomized to receive one of two levels of remifentanil TCI (2 ng/ml or 4 ng/ml). Both levels are accepted and used as standard of care. [0180] c. Rescue pain medication during surgery: boluses of 0.05 mg fentanyl upon anesthesiologist's decision. [0181] d. All subjects were administered 100 mg tramal approximately 20 minutes prior to end of surgery.
Nociceptive Stimulations
[0182] 1. Experimental noxious stimuli: After anesthesia induction with midazolam and propofol all subjects were subjected to two standardized and similar experimental stimuli (Tetanic stimuli, 60 mA, 100 Hz for 20 seconds) before and 3 minutes after a standardized bolus of 2 g/kg fentanyl. Tetanic stimuli level was chosen according to standards in the field of anesthesia and pain research. [0183] 2. Clinical noxious stimuli: Intubation and skin incision/first trocar insertion.
[0184] The list of stimuli and their expected nociceptive levels are detailed in table 3.
TABLE-US-00003 TABLE 3 Nociceptive stimuli Abbreviation Level of expected pain Stimulus TP1 Moderate-severe noxious Intubation stimulus TP2 Mild-moderate noxious First incision/trocar stimulus insertion TET1 Mild noxious stimulus Tetanic without analgesia TET2 Minor noxious stimulus Tetanic with analgesia TNP Non-noxious period Non-noxious period
Data Collection
[0185] 1. The subject's vital and physiological signals were recorded from the subject monitor by S/5TM Collect (GE healthcare, Helsinki, Finland) to an external PC. [0186] 2. The subject was connected with sensors to the monitoring device. The signals and the real time-derived nociception scale (NS) values were recorded to an external PC. [0187] 3. During anesthesia and surgery, the following events were noted on the Software event log: [0188] Noxious events defined by the PI. [0189] Dose and time of administration of medications including: analgesics, hypnotics, muscle relaxants, and any drug affecting the subject's hemodynamics. [0190] Clinical signs perceived to correlate to pain or arousal (movement, tearing, sweating, and spontaneous breathing when appropriate). [0191] Any other relevant data according to the anesthesiologist's judgment.
Statistical Analysis
[0192] The following nociception-related physiological parameters and indices collected in the trial were analyzed: [0193] Nociception Scale (NS) [0194] Physiological parameters: Heart Rate (HR), non-invasive blood pressure (NIBP), photo-plethysmograph amplitude (PPGA) (GE Datex Ohmeda, Helsinki, Finland). [0195] Surgical Pleth Index (SPI) (GE Datex Ohmeda, Helsinki, Finland).
[0196] For each subject the response around 4 noxious stimuli and 1 non-noxious stimulus was computed and analyzed.
[0197] The noxious/non noxious stimuli for analysis are as follows: [0198] First tetanic stimulation without analgesics (TET 1). [0199] Second tetanic stimulation following 2 g/kg fentanyl (TET2). [0200] Intubation (TP1). [0201] First incision/trocar insertion (TP2). [0202] Non-noxious period (TNP). TNP was annotated before first skin incision/trocar insertion and after intubation, with relation to a non-noxious marking such as cleaning and covering of the subject. A mandatory requirement was to have at least a 5-minute window around annotation (2.5 minutes before and 2.5 minutes after) with no nociception-related event annotation.
[0203] From each of the analyzed parameters three measures were extracted for comparison prior (Pre), after (Post), and during (Reaction) to each stimulus: [0204] Pre stimulus value of parameter: the average value of the parameter was calculated in a window of (60) to (30) seconds before stimulus. [0205] Post stimulus value of parameter: the average value of the parameter was calculated in a window of (+10) to (+80) seconds after the stimulus for all stimuli. [0206] Post-long stimulus value of parameter: for comparison between two levels of remifentanil after first skin incision/trocar insertion, the average value of the parameter was calculated in a window of (+10) to (+400) seconds (applied after TP2 only). [0207] Reaction () of parameter:
[0208] Statistical analyses were performed using IBM SPSS Statistics for Windows version 22.0 (IBM Corp., Armonk, N.Y.) and MATLAB R2014a scientific software (Mathworks, Inc., Natick, Mass., US). Descriptive statistics are presented for demographic data whereas continuous data are represented by a median and 25th-75th percentiles. Categorical data are presented by a count and percentage.
[0209] P-value of 0.05 is regarded as significant. A Bonferroni correction was applied to maintain a type one error over 8 comparisons, i.e., post and reaction values of the NS, HR, PPGA and SPI. Therefore p-value for significance is 0.05/8=0.00625. Hence throughout the report, for both primary endpoints analysis and for the first of the secondary endpoints, p-values of 0.00625 are regarded significant.
[0210] For the second of the secondary endpoints analysis a p-value of 0.01 is regarded significant, after Bonferroni correction, since only 5 nociception-related parameters are compared, i.e. NS, NIBP, HR, PPGA, and SPI (0.05/5=0.01).
Results
[0211] The analysis included 58 subjects: 37 males, 21 females. Mean subjects' age was 46.113.1 years, mean subjects' BMI was 29.57.5. Surgeries included: open and laparoscopic general and gynecological surgery, ear nose & throat surgery, neurosurgery and plastic surgery.
[0212] Response to clinical and experimental noxious stimuli
[0213] The response of NS and other parameters to clinical stimuli was investigated based on annotations of TP1, TP2 and TNP, per parameter/index. The median values and IQR (25th and 75th percentiles) of each parameter/index pre, post, and as a reaction to the clinical stimuli are presented in Table 4.
TABLE-US-00004 TABLE 4 Pre and post median [25th-75th percentile] values and the reaction to clinical and experimental stimuli, per parameter. NS HR PPGA* SPI Median [25%-75%] Median [25%-75%] Median [25%-75%] Median [25%-75%] TP1 pre 15.3 [4.2-23.1] 66.7 [60.2-74.3] 5.4 [4.3-7.7] 24 [19.8-27.6] TP1 post 36.2 [23.8-47.0] 79.9 [70.2-85.6] 3.7 [2.9-5.1] 42.5 [35.2-52.5] TP1 reaction 21.2 [10.8-30.2] 17.0% [8.0%-26.0%] 34.0% [[(45.8%)-(13.5%)] 20 [10.3-25.9] TP2 pre 4.8 [2.7-17.1] 61.5 [51.6-66.4] 4.9 [3.1-7.1] 26.7 [20.6-39.8] TP2 post 15.5 [7.2-29.1] 63.4 [53.0-68.1] 3.8 [2.3-5.5] 42.6 [28.2-54.6] TP2 reaction 5.2 [0.6-12.9] 2.2% [(1.4%)-5.0%] 18.0% [(36.1%)-(2.6%)] 7.9 [2.6-16.9] TNP pre 5.3 [2-12] 64 [52-69] 5 [3-7.5] 28 [21-39] TNP post 3.7 [2.1-7.4] 63 [52-68] 4.7 [2.9-7.6] 28 [19-37] TNP reaction 0.78 [(4.3)-1.2] 1.2% [(2.2%)-0] 0.25% [(7.4%)-6.6%] 0.16 [(2.3)-2.3] TET1 pre 30.1 [20.0-46.0] 77.7 [68.4-83.7] 1.7 [0.9-3.5] 51.7 [40.8-68.6] TET1 post 44 [31.8-53.8] 79.1 [68.9-88.5] 3.3 [1.8-4.9] 41.7 [33.6-46.9] TET1 reaction 9.5 [(2.5)-19.6] 0.2% [(5.4%)-8.3%] 78.5% [24.7%-138.7%] 14.5 [(22.1)-3.3)] TET2 pre 11.6 [4.9-28.4] 66.3 [58.8-74.6] 4.8 [3.5-5.8] 24.6 [22.5-38.0] TET2 post 18.8 [12.0-30.9] 68.8 [59.2-75.1] 4.8 [3.5-5.8] 27.8 [22.5-38.0] TET2 reaction 5.8 [(2.4)-15.8] 1.6% [(2.6%)-6.4%] 5% [(18.1%)-10.1%] 2.4 [(1.4)-7.0] *HR, SPI and NS are expected to rise in response to noxious stimuli while PPGA is expected to decrease in response to noxious stimuli.
[0214] The reaction of NS in response to intubation (TP1) and first incision/trocar insertion (TP2) was statistically significant (p<0.0001), increasing by a median reaction value of 21.2 and 5.2, respectively, and was non-significant around non-noxious period (TNP).
[0215] The reaction of HR was statistically significant only after TP1, increasing by a median reaction value of 17% (p<0.0001). The reduction of HR from a post median value of 64 BPM to 63 BPM around TNP was statistically significant, but with no clinical significance.
[0216] The reaction of PPGA and SPI in response to TP1 and TP2 was statistically significant (p<0.0001) and was non-significant around non-noxious period (TNP).
[0217] The values of NS and other parameters in response to experimental tetanic stimuli were also analyzed. The NS reaction to TET1 and TET2 was statistically significant (median reaction values 9.5 and 5.8; p=0.0006 and p=0.0051, respectively). HR did not change with statistical significance following both tetanic stimulations. SPI and PPGA's reaction in response to TET1 were opposite to expected, failing to recognize it as a noxious stimulus. SPI increased with statistical significance in response to TET2 (p=0.0025). PPGA changed non-significantly around TET2.
[0218] These result show that NS successfully reacted as predicted, changing with statistical significance after noxious clinical stimuli (TP1, TP2), while not reacting during non-noxious period (TNP). In addition, NS increased significantly in response to experimental tetanic stimuli, TET1 and TET2 (median rise of 9.5 and 5.8 points; p=0.0006, p=0.0051, respectively).
[0219] In the analysis testing the ability of parameters and indices to discriminate between noxious (TP1, TP2) and non-noxious stimuli (TNP), a predefined study outcome measure of AUC 0.8 was set. NS reached an AUC of 0.93 [CI 0.89-0.97], outperforming AUC of all other parameters/indices, including SPI, SPI, HR, HR, PPGA and PPGA (with the lower confidence interval for NS (0.89) being higher than the mean AUCs of those parameters). NS reached an AUC of 0.89 [CI 0.85-0.94], also higher than all other tested parameters/indices.
Discriminate Between Clinical Noxious Stimuli and Non-Noxious Periods
[0220] All 58 valid subjects were included in this analysis.
[0221] The AUC for NS and NS was 0.93 [CI 0.89-0.97]) and 0.89 [CI 0.85-0.94], respectively, higher than the predefined study outcome measure of 0.8.
[0222] Other tested parameters reached lower AUCs: HR (0.67 [CI 0.58-0.75]), HR (0.82 [CI 0.76-0.89]), PPGA (0.62 [CI 0.53-0.71]), PPGA (0.81 [CI 0.74-0.88]), SPI (0.73 [CI 0.65-0.81]), and SPI (0.88 [CI 0.83-0.93]).
[0223] The sensitivity achieved by NS (86.67% [CI: 78.64%-92.51%]) and NS (80.00% [CI 71.07%-87.17%]) was higher than all other individual parameters/indices tested at specificity of 84%, as listed below in descending order: HR 75.76% [CI 66.42%-83.59%], SPI 79.59% [CI 70.62%-86.83%]), PPGA 63.64% [CI 53.68%-72.80%]), HR 37.37% [CI 28.12%-47.35%]), SPI 42.86% [CI 33.24%-52.89%]) and PPGA 21.21% [CI 35.18%-54.91%]).
Grading the Response to Different Noxious Stimuli
[0224] A repeated measures model was applied for grading the response of the following parameters in the post stimuli window: NS, HR, PPGA and SPI. The model assumed a relation such that TP1 is more intense than TP2 and both are more intense than TNP. For each parameter, only subjects with full sets of annotations for all three stimuli were included in analysis: 44, 42, 42 and 41 subjects for NS, HR, PPGA, and SPI, respectively. A Friedman test was conducted to look for a significant statistical difference between TP1, TP2 and TNP. In case of p-value<0.00625 a post hoc test (Dunn-Sidak) was conducted to verify which of the two groups differ.
[0225] Based on the analysis presented in Table 5 below, both NS and NS were the only indices to successfully grade the response to clinical stimuli as expected: TP1>TP2>TNP.
TABLE-US-00005 TABLE 5 Grading the response to clinical stimuli TP1, TP2, TNP by post and reaction () values. Freidman test analysis. Post Reaction NS HR PPGA SP1 NS HR PPGA ASP1 Friedman <.00001 <.00001 .017 .0012 <.00001 <.00001 <.00007 <.00001 p-value TP1 vs 0.0013 <.00001 .61929 .92636 .00415 .0001 .92872 .10385 TP2 TP1 vs. <.00001 <.00001 .01361 .00185 <.00001 <.00001 .00016 <.00001 TNP TP2 vs. .0001 .99485 .22348 .1222 .00037 .03583 .00144 .00003 TNP *p-value < 00625 (after Bonferroni correction .05/8), a Post Hoc (Dunn-Sidak) test was conducted to verify which of the two groups differ. Significant p-values are in bold.
[0226] HR and HR successfully graded TP1>TP2 and TP1>TNP, but failed to grade TP2>TNP. PPGA failed to grade the three events. PPGA significantly graded TP1>TNP and TP2>TNP, but failed to grade TP1>TP2. SPI successfully graded TP1>TNP, but failed to grade TP2>TNP and TP1>TP2. ASPI successfully graded TP1>TNP and TP2>TNP, but failed to grade TP1>TP2.
[0227]
[0228] Different reaction to a noxious stimulus under different levels of analgesics
[0229] To assess the effect of two analgesic doses in response to TP2 (first incision/trocar insertion), subjects were randomized between two groups of remifentanil TCI: 2 ng/ml (low dose) and 4 ng/ml (high dose). There was no difference in demographic and other characteristics between groups. A post-long stimulus window of +10 to +400 seconds was chosen for this analysis aiming to include at least 4 trocar insertions and skin incision with underlying tissue separation. This was the only analysis allowing the inclusion of NIBP in the model due to the relatively long window allowing collection of a sufficient number of data points (sampled every 3-5 minutes). Post-long TP2 values were compared between the two groups of analgesia by Mann-Whitney U test, expecting a lower value in the higher analgesic dose.
[0230] The results are presented in table 6 below.
TABLE-US-00006 TABLE 6 Reflection of different levels of analgesics during noxious (post-long TP2) period. Comparison Pre post TP2 post- 2 vs. 4 Mann within dose Remifentanil TP2 pre long TP2 reaction Whitney test Wilcoxon dose Median Median Median Post-long sign rank ng/ml [25%-75%] [25%-75%] [25%-75%] p-value test NS 2 10.84 21.67 4.965 0.0069 0.0027 (abs) [3-17.72] [12.86-31.24] .sup.[1.17-14.97] 4 3.077 11.38 3.404 0.014 [2.171-8.646] [4.929-18.89] [(1.07)-10.11] HR 2 62.01 64.11 3.35% 0.27 0.073 (BPM, [54.59-68.87] [54.75-71.29)] [(.72%)-6.49%] %) 4 61.21 63.16 1.16% 0.47 [51.66-66.36] [52.2-66.83] [(3.07%)-2.39%] PPGA 2 4.411 4.071 (25.34%) 0.13 0.0009 (abs, %) [1.791-6.612] [1.206-5.191] [(103.2%)-(7.38%].sup. 4 4.998 4.189 (3.62%) 0.07 [3.15-7.628] [2.828-7.112] [(40.89%)-5.15%] SPI 2 35.71 48.76 8.294 0.027 0.001 (abs) [23.34-48-17] [30.62-62.72] .sup.[2.31-22.51] 4 24.91 33.14 3.562 0.03 [23.04-44.53] [(2.09)-13.27] NIBP 2 88 103.7 10% 0.16 0.0003 (mmHg, [84.28-96.05] [92.69-108.8] .sup.[4.2%-15.69% %) 4 83 92.92 3.8% 0.01 [74-101.8] 183.13-1021.sup. [(.067%)-11.93%] Statistical significance: p < 01 (after Bonferroni correction).
[0231] Only NS reached significance with a post-long stimulus median value of 21.67 (low dose) vs. 11.38 (high dose) (p=0.0069). A paired within-dose comparison of the reaction (ATP2) revealed a significant reaction in the low dose group combined with a non-significant reaction in the high dose group for NS, PPGA, SPI and NIBP. HR did not react significantly to TP2 at any analgesic dose, remaining between 61 and 64 BPM. These results shows the ability of the NS to identify nociception in patients administered with a below optimal dose of an analgesic as well as discriminating between different levels of nociception in correlation with the dose of the analgesic administered.
[0232] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms a, an and the are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms comprises or comprising, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, or components, but do not preclude or rule out the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.
[0233] Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as processing, computing, calculating, determining, estimating, or the like, refer to the action and/or processes of a computer or computing system, or similar electronic computing device, that manipulate and/or transform data represented as physical, such as electronic, quantities within the computing system's registers and/or memories into other data similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or display devices.
[0234] Embodiments of the present invention may include apparatuses for performing the operations herein. This apparatus may be specially constructed for the desired purposes, or it may comprise a general purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs) electrically programmable read-only memories (EPROMs), electrically erasable and programmable read only memories (EEPROMs), magnetic or optical cards, or any other type of media suitable for storing electronic instructions, and capable of being coupled to a computer system bus.
[0235] The processes and displays presented herein are not inherently related to any particular computer or other apparatus. Various general purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the desired method. The desired structure for a variety of these systems will appear from the description below. In addition, embodiments of the present invention are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the inventions as described herein.
[0236] The invention may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, and so forth, which perform particular tasks or implement particular abstract data types. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.
[0237] While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced be interpreted to include all such modifications, additions and sub-combinations as are within their true spirit and scope.