METHOD OF ESTIMATION OF THE HEMODYNAMIC STATUS AND CAPACITY OF EFFORT FROM PATIENTS WITH CARDIOVASCULAR AND PULMONAR DISEASES
20230404413 · 2023-12-21
Inventors
Cpc classification
A61B2576/02
HUMAN NECESSITIES
G16H50/20
PHYSICS
A61B5/7264
HUMAN NECESSITIES
A61B5/0075
HUMAN NECESSITIES
G16H50/30
PHYSICS
A61B5/02055
HUMAN NECESSITIES
A61B5/4848
HUMAN NECESSITIES
A61B5/029
HUMAN NECESSITIES
G16H50/70
PHYSICS
A61B5/4809
HUMAN NECESSITIES
A61B5/1121
HUMAN NECESSITIES
International classification
A61B5/0205
HUMAN NECESSITIES
A61B5/029
HUMAN NECESSITIES
A61B5/00
HUMAN NECESSITIES
G16H50/30
PHYSICS
G16H50/20
PHYSICS
G16H50/70
PHYSICS
Abstract
The invention described herein is a method that can predict: according to a Modality A, the effort capacity of a human individual as an expression of distance walked by the individual if subjected to a 6MWT; and according to Modality B, the hemodynamic state of the patient as an expression of CI and SVR. The method is comprised of four steps: (1) capturing a series of thermal images of the face and hands of a human individual, according to the modality; (2) applying established temperature values for a series of specific spots from the face and the hands, according to the modality; (3) selecting general additional parameters, from the patient and the environment; and (4) implementing algorithms discovered through the ML technique, through which the previously mentioned parameters are analyzed
Claims
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10. A non-invasive diagnostic method of diagnosing cardiovascular performance by clinical testing to determine the hemodynatnic state and the effort capacity of an individual subjected to trial, the method comprising the steps of: capturing thermal images utilizing an infrared thermographic camera from one of a) a face and a hand of the individual, and b) a front and lateral side of the face of the individual; entering the thermal images on a magnetic medium to be analyzed; on the captured thermal images, determining temperature values of a series of specific preselected points in established regions of the individual; analyzing said temperature values through a library of code and software of the infrared thermographic camera, which allows an interpretation of infrared color spectrum and translation into temperature in degrees centigrade; entering on a magnetic medium additional data consisting of general parameters of the individual and the environment in which the method is taking place; and analyzing the acquired data obtained through the previous steps by means of predictive Machine Learning (ML) techniques in order to predict the results of: i) a distance walked by the individual if subjected to a Six-Minute Walk Test (6MWT), or ii) a Cardiac index (CI) and Systemic Vascular Resistance (SVR) of the individual if subjected to hemodynamic monitoring with Swan-Ganz catheter, if the individual is subjected to either of tests i) and ii).
11. The method of claim 10, wherein the temperature values are determined through thermal images from the front and the lateral side of the individual's face, and the palm of the individual's hand.
12. The method of claim 11, wherein the temperature values are determined from the captured thermal images in regions of the front and lateral side of the individual's face selected from a left eye, a right eye, a nose, an interciliar region, a dihedral angle formed by the nose and the infraorbital region, an ear canal and a pinna, and in regions of the individual's palm of a hand selected from a wrist, a central region of the palm and fingertips.
13. The method of the claim 12, wherein only a hottest point and a coldest point of each region are considered to determine the temperature values.
14. The method of the claim 13, wherein the hottest points are elected from the left eye (Oi), the right eye (Od), a tip of the nose (Na), the dihedral angle formed between the nose and infraorbital region (ADEC), the ear canal (Ca), and the pinna (Pa), the wrist, the central region of the palm of the hand and the fingertips.
15. The method of the claim 13, wherein the coldest points from the nose (NRF) and the interciliar regions (ICF).
16. The method of claim 1.3, wherein when the 61MWT is predicted, thermal gradients are established a) between the temperature values of the right eye and the nose (NO gradient), b) between the temperature values of ear canal and the pinna (CP gradient), and c) between the temperature values of distinctive points of the hand.
17. The method of claim 13, wherein when the CI and SVR are predicted, thermal averages are established a) between the ICF, the NRF and the ADEC, b)at the OP, and c) between ADEC and ICF.
18. The method of the claim 10, wherein the general parameters from the individual are at least one of a gender, a size, a weight and a cardiac frequency, a blood pressure, a functional class, a vasodilator drugs the patient is taking and an oxygen saturation.
19. The method of the claim 10, wherein the general parameters from the individual are at least one of a gender, a use of intravenous vasoconstrictor or vasodilator drugs, an awake or an asleep state, and an approximative value of central venous pressure (PVC) in the right atrial.
20. The method of the claim 10, wherein the additional general parameters from the individual are at least one of gender, use of intravenous vasoconstrictor or vasodilator drugs, awake or asleep state, and an approximative value of central venous pressure (PVC) in the right atrial.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0026] The features and advantages of the present invention will become more readily apparent from the following detailed description of the invention in which like elements are labeled similarly and in which:
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DETAILED DESCRIPTION OF THE INVENTION
[0047] With the purpose of avoiding the inconvenience of previous methods, a methodology consisting of two modalities is proposed: [0048] Modality A: estimation of the patient's effort capacity [0049] Modality B: estimation of the patient's hemodynamic state
[0050] Based on the previously stated physiological concept, we understand that the higher the cardiovascular performance, the higher temperature of specific spots on the skin of the face or the extremities. These spots can be found further away from the heart. Since these spots have terminal blood circulation, they are called distal or acral regions. Examples of distal regions are: extremities of the fingers, ears or nose.
[0051] Consequently, we can infer the following: [0052] 1. The temperature of these distal regions can be directly related to the CO and the effort capacity, and inversely related to the SVR of the patient. [0053] 2. When comparing the temperature of the distal regions with respect to the proximal regions, a thermal gradient can be established. This thermal gradient between such areas could be inversely proportional to the CO and the effort capacity, and directly proportional to the SVR, since the higher the SVR, the worse the blood circulation.
[0054] The register of the temperature in the different spots of interest on the skin from the patients can be obtained through the capture of thermal photos, taken by any thermographic of infrared camera. This camera is a device that, based on the emission of infrared media from the electromagnetic spectrum from the detected bodies, creates luminous images visible to the human eye, i.e. thermal photographs.
[0055] To put the invention into practice, two types of study were needed. The first one served the purpose of predicting the effort capacity, and the second one that of predicting hemodynamic behavior. Both studies had the purpose of finding which thermal spots and the thermal gradients were related to the aforementioned cardiovascular behaviors.
First Research
[0056] Patients with Pulmonary Hypertension (PH) were analyzed via the use of thermal pictures. PH is a disease that produces heart failure and healthy subjects served as a comparative. After the capturing of the thermal photos, the subjects underwent a 6MWT and the distance completed was measured. The professional in charge of the analysis of the thermal images was unaware (blind) with regards to the results of the 6MWT.
[0057] All of the testing was completed under controlled conditions with regards to temperature, humidity and luminosity, as well as being performed in the same physical place, which served the purpose of ensuring no significant variation in the aforementioned environmental parameters. The devices employed in the testing were a FLIR ONE thermal camera, attached to a SAMSUNG A5 cellphone. Employing the use of the thermal camera, three captures of thermal images were taken of the fact from the frontal view, along with three captures from the profile and three more from the palm of the right hand. An average of the thermal values of each of the three images obtained per region was calculated with the purpose of reducing the margin for error with regards to measurement. Every image was taken keeping the distance between the camera and the region of interest to lesser than 30 cm.
[0058] The subjects undergoing the testing had to remain resting in a sitting position in a chair for at least 15 minutes, away from any source of extreme temperatures such as heaters, fridges, fans, air conditioning and the like. The subjects were not able to wear contact lenses, glasses, facial or ear piercings, rings or bracelets, nor any type of adornment that could interfere with the measurement of the skin temperature.
[0059] Subjects with skin damage, infections in the breathing area or in their ears, untreated thyroid gland disease or any kind of acute infection were excluded, since these conditions could modify the temperature.
[0060] After the capture of the images, the subjects were put under testing and the 6MWT following the recommendations present in any international guidelines that describe and validate such testing, and the distance completed in this test was measured.
[0061] The test was experimental and transversal, recruiting patients in a prospective way. 55 cases were analyzed, 39 patients with PH and 16 healthy subjects. The average age of said subjects/patients was 45.7415.5 years and 84% of the patients were women. Consecutive patients were included, i.e. without going through selection, and the PH diagnosis was defined by international criteria for precapillary PH by right cardiac catheterization. The images obtained were analyzed through a library of code and software provided by the supplier of the thermal camera, which allows for the interpretation of the infrared color spectrum and translation into temperature in degrees centigrade.
[0062] Higher temperatures were registered in the following regions: eyes, right auditive conduct and the Pterion region, whereas the lowest temperatures were obtained in the nasal region and the right auditive pavilion.
[0063] Regarding the palm of the hand, the registered temperatures were higher in the following regions: wrist, center of the palm and fingertips.
[0064] The thermal gradients (TG) were established between NO and CP. The comparative was performed between the TG from PH patients and the TG from the control group.
[0065] Moreover, anthropometric data was registered, such as age, type of disease for the group of PH patients, arterial pressure and oxygen saturation. Whether the patients were taking any medication that could generate cutaneous vasodilation was also taken into account.
[0066] The numeric variables were expressed as mean and DS. The TG's were compared with the Student Test. Then the Pearson correlation was applied between TG and the distance walked during the 6MWT. A p<0.05 was considered significant.
[0067] The following results were obtained in relation to the distance walked in the 6MWT: 386151 versus 53388 mts (<0.001) for PH and controls, respectively. See Chart 1 below:
TABLE-US-00001 Pre 6MWT Post 6MWT PH PH Areas or regions patients CONTROLS p patients CONTROLS p FACE, Right eye 37.3 2.5 37 3.2 0.65 35.1 2.3 35.6 2.9 0.41 FRONT Nose 30.6 3.4 31.6 3.6 0.21 27 3.5 28.2 3.5 0.20 ( C.) Thermal 6.7 2 5.6 2.6 0.05 8 2.3 7.6 2 0.42 Gradient RE-N FACE, Ear Canal 38.1 1.6 38.1 2.2 0.99 36.4 2.3 36.9 2 0.35 SIDE External Ear 31 2.4 31.3 2.8 0.62 27.8 3 29.5 2.7 0.01 ( C.) Thermal 7.2 1.5 6.9 1.8 0.47 8.6 1.5 7.5 2.7 0.02 Gradient EC- EE PALM OF Central Area 34.4 2.9 35.2 2.5 0.33 31.5 3.2 33.1 3.2 0.09 THE 1 finger 29.5 4.6 32 4 0.06 25.3 4.6 29.3 5.3 0.008 RIGHT 2 finger 28.9 4.4 31.6 4.2 0.04 24.5 4.6 28.9 5.3 0.003 HAND 3 finger 29 4.5 31.1 3.9 0.12 24.4 4.9 28 5.4 0.02 ( C.) 4 finger 28.8 4.4 31 4.4 0.10 24 4.6 28.1 5.8 0.009 5 finger 28.8 4.5 31 4.5 0.12 23.9 4.6 28.1 6.1 0.009
[0068] Chart 1 shows the thermal differences between PH and controls, registered before performing the 6MWT. For a better understanding and evaluation of the method, several thermal images were taken after the 6MWT.
[0069] The subjects with PH present a lower temperature in the distal regions in comparison with the healthy controls. Although some thermal differences between both groups can be quantified, some differences were meaningful while others were not. At first approach, this could be explained by the limited number of the sample.
[0070] When taking into account the total number of individuals in the test, i.e. those with PH and healthy people, a clearly established and meaningful thermal gradient was found, which proves that distal regions show a lower temperature than the central regions. See Chart 2 below:
TABLE-US-00002 Regions Basal (pre 6MWT) Final (Pos 6MWT) Com- Coefficient Coefficient pared IC 95 p IC 95 p Wrist vs 0.99 0.88-1.1 <0.001 1.02 0.9-1.15 <0.001 RCP RCP vs 1.39 1.2-1.6 <0.001 1.42 1.22-1.62 <0.001 PTD
[0071] Chart 2 shows the figures for the beta coefficients when comparing the three regions before the 6MWT and when completed; wrist vs. central region of the front of the hand (RCP), and RCP vs. Five Fingers Temperature Average (PTD).
[0072] The temperature registered in the palm of the hand before the 6MWT showed a thermal gradient descending through the distal regions, with the temperature of the wrist at 35.22.7 C., superior to the temperature of the central region from the palm of the hand, 34.82.9 C., and the registered average temperature of the five fingers, 29.84.6 C. This gradient of temperature, from proximal to distal, was in turn evident when finishing the exercise: wrist 32.42.8 C.; central region 32.13.2 C.; average of the five fingers 25.75 C. All the differences were statistically significant (p<0.001).
[0073] A correlation was determined between the TG and the 6MWT (see
[0074] Consequently, the following was established: (1) the existence of thermal gradients with descending temperature through the distal regions; (2) the existence of a link between thermal gradients and meters walked by the patients during the 6MWT, which explains that, the higher the thermal gradient, the lower the distance completed during the 6MWT; and (3) it was observed that the value of these thermal spots and their behavior during physical exertion is different between ill subjects and healthy ones.
Second Research
[0075] A prospective test was performed on patients hospitalized in Critical Care Units, who had to be monitored in an invasive way by the use of Swan-Ganz catheter.
[0076] The age average was 58 years, 70% were men, 28% were sedated and on mechanical respiratory assistance (MRA). 41.6% were taking endovenous vasoconstricting drugs, such as norepinephrine, epinephrine and/or vasopressin; 25% were taking vasodilating drugs, such as milrinone, dobutamine and/or sodium nitroprusside; 25% were taking both types of drugs, and 8.3% none of the aforementioned.
[0077] Hemodynamic measurements were performed through Swan-Ganz and the thermodilution method; at the same time, facial thermal images were taken. In every thermal test of the face, i.e. the capture of three images at the same time, the central venous pressure in the right auricle (PVC), the pulmonary interlocking pressure (Pw), systemic average arterial pressure (TAM), cardiac frequency (CF), cardiac minute volume (CMV), cardiac index (CI) and systolic work index of the right/left ventricle (SWIRV, SWILV) were registered.
[0078] Thermal images from the front of the patients' face were obtained at a distance of 10 cm and the best links between thermal spots and gradients were researched, along with the majority of the hemodynamic variables already mentioned. The tested thermographic variables were correlated with the Pearson and the Spearman Tests. p<0.05 was considered to be a statistically significant value.
[0079] Correlations with significant statistical value were found for both Spearman and Pearson tests between CI and SVR with different thermal spots, but not for other hemodynamic variables, except for that of the PVC.
[0080] It was found that these correlations between spots and gradients with CI and SVR had different results and, unexpectedly, we found that they depended mainly on the state of the patient being tested: awake versus sedated, receiving vasodilating drugs vs. vasoconstrictors; with a high vs. low PVC and also according to the gender. See Charts 3, 4 and 5 below:
TABLE-US-00003 Correlation by means of the Pearson Test of the Cardiac Index with different points and thermal gradients CVP r2- r2- Total r2- r2- r2- Total Temperature popu- r2- Sleep- Vaso- Vaso popu- points lation p Awake p ing p dilators p constrictors p lation p OP 0.26 0.13 0.13 0.5 0.74 0.02 0.06 0.8 0.36 0.15 0.33 0.054 OP4 0.29 0.08 0.18 0.37 0.74 0.02 0.09 0.7 0.4 0.11 0.33 0.047 ICF 0.42 0.012 0.28 0.16 0.8 0.008 0.13 0.5 0.63 0.006 0.42 0.012 ADEC 0.41 0.014 0.4 0.04 0.68 0.04 0.36 0.14 0.48 0.05 0.35 0.035 NRF 0.37 0.027 0.43 0.028 0.75 0.018 0.29 0.23 0.51 0.037 0.37 0.029 NPC 0.33 0.05 0.38 0.05 0.44 0.23 0.36 0.14 0.31 0.22 0.2 0.24 NPF 0.31 0.06 0.36 0.06 0.45 0.22 0.35 0.15 0.29 0.25 0.22 0.19 Pr ADEC-ICF 0.42 0.01 0.35 0.07 0.76 0.017 0.25 0.3 0.57 0.016 0.4 0.017 Pr ICF-NRF 0.42 0.013 0.4 0.04 0.79 0.011 0.25 0.31 0.58 0.014 0.41 0.013 Pr ADEC-NRF 0.4 0.016 0.44 0.023 0.72 0.027 0.33 0.17 0.52 0.032 0.38 0.024 Pr3 ADEC- 0.42 0.011 0.41 0.034 0.76 0.017 0.28 0.24 0.56 0.018 0.4 0.015 ICF-NRF Sumatoria 0.39 0.017 0.33 0.09 0.76 0.016 0.18 0.46 0.57 0.01 0.4 0.011 X1 Gr OP-ADEC 0.35 0.039 0.5 0.009 0.35 0.35 0.59 0.009 0.22 0.38 0.09 0.58 Gr OP-ICF 0.41 0.014 0.41 0.037 0.22 0.57 0.25 0.3 0.48 0.05 0.25 0.13 Gr OP-NRF 0.29 0.08 0.42 0.03 0.59 0.09 0.32 0.19 0.4 0.1 0.24 0.16 Gr OP-Pr 0.45 0.006 0.53 0.005 0.03 0.9 0.56 0.01 0.42 0.09 0.21 0.23 ADEC-ICF Gr OP-Pr ICF- 0.36 0.03 0.44 0.023 0.42 0.25 0.33 0.17 0.49 0.046 0.27 0.11 NRF Gr OP-Pr 0.33 0.049 0.47 0.015 0.21 0.57 0.42 0.08 0.4 0.1 0.21 0.21 ADEC-NRF Gr3 OP-Pr 0.38 0.022 0.48 0.013 0.25 0.5 0.42 0.08 0.47 0.056 0.25 0.15 ADEC-ICF- NRF Correlation by means of the Spearman Test of the Cardiac Index with different points and thermal gradients CVP r2- r2- Total r2- r2- r2- Total Temperature popu- r2- Sleep- Vaso- Vaso popu- points lation p Awake p ing p dilators p constrictors p lation p OP 0.16 0.34 0.13 0.52 0.83 0.005 0.04 0.88 0.33 0.19 0.37 0.027 OP4 0.22 0.2 0.2 0.31 0.81 0.007 0.08 0.74 0.35 0.16 0.38 0.021 ICF 0.3 0.07 0.17 0.38 0.79 0.01 0.006 0.97 0.64 0.005 0.42 0.011 ADEC 0.3 0.07 0.33 0.09 0.81 0.007 0.28 0.25 0.45 0.06 0.34 0.044 NRF 0.32 0.058 0.38 0.054 0.81 0.007 0.2 0.41 0.49 0.04 0.4 0.016 NPC 0.28 0.09 0.35 0.07 0.55 0.11 0.38 0.11 0.26 0.3 0.24 0.15 NPF 0.2 0.11 0.34 0.08 0.59 0.09 0.35 0.15 0.24 0.34 0.26 0.12 Pr ADEC-ICF 0.29 0.08 0.24 0.23 0.85 0.0039 0.12 0.6 0.58 0.013 0.4 0.016 Pr ICF-NRF 0.28 0.09 0.31 0.12 0.85 0.0039 0.13 0.58 0.53 0.027 0.43 0.01 Pr ADEC-NRF 0.31 0.06 0.35 0.07 0.81 0.007 0.18 0.46 0.48 0.051 0.37 0.029 Pr3 ADEC- 0.31 0.06 0.33 0.09 0.85 0.0039 0.15 0.53 0.55 0.021 0.41 0.014 ICF-NRF Sumatoria 0.29 0.08 0.22 0.27 0.85 0.0039 0.04 0.86 0.61 0.009 0.45 0.0068 X1 Gr OP-ADEC 0.35 0.039 0.47 0.014 0.3 0.42 0.65 0.0037 0.26 0.3 0.11 0.5 Gr OP-ICF 0.27 0.11 0.26 0.18 0.01 0.96 0.01 0.93 0.35 0.16 0.2 0.27 Gr OP-NRF 0.33 0.053 0.41 0.034 0.37 0.32 0.29 0.23 0.44 0.07 0.31 0.06 Gr OP-Pr 0.39 0.019 0.42 0.03 0.1 0.79 0.46 0.054 0.41 0.09 0.18 0.28 ADEC-ICF Gr OP-Pr ICF- 0.33 0.055 0.38 0.054 0.15 0.69 0.23 0.35 0.4 0.1 0.34 0.044 NRF Gr OP-Pr 0.38 0.024 0.48 0.013 0.08 0.82 0.41 0.08 0.4 0.1 0.28 0.1 ADEC-NRF Gr3 OP-Pr 0.37 0.027 0.44 0.025 0.11 0.76 0.37 0.12 0.43 0.07 0.3 0.07 ADEC-ICF- NRF
[0081] Chart 3 shows the correlation between the Person Test and the Spearman Test of the Cardiac Index with different thermal spots and gradients, such as: OP4, the average of the hottest spots on each eye, ICF, temperature of the coldest spot in the interciliar region; ADEC, the highest temperature of the region of the dihedral angle formed between the nose and the infraorbitrary region; NRF, the coldest temperature of the region of the root of the nose; NPC, hottest temperature of the region of the tip of the nose; NPF, the coldest temperature of the region of the tip of the nose; Pr ADEC-ICF, the thermal average between both spots; Pr ADEC-NRF, the thermal average between both spots; Pr3 ADEC-ICF-NRF, thermal average between the three spots; Sum X1, the sum of the temperature of the five thermal spots from the face; ICF, the hottest interciliar spot, average interciliar temperature, NRF and average temperature of the root of the nose; Gr, the thermal gradient between both spots; r2 Awake, correlation value in waking patients; r2-MRA, correlation value in patients with mechanical respiratory assistance; r2 VD or nothing, correlation value in patients with vasodilating drugs or without any kind of drug; r2 VC or both, correlation value in patients with vasoconstrictor drugs or VC plus VD; CVP, central venous pressure.
TABLE-US-00004 Pearson's Test Blood CVP-Blood Wedge Temperature Pressure Pressure Pressure Heart Rate LVSWI RVSWI points r2 p r2 P r2 p r2 p r2 p r2 p OP 0.22 0.19 0.02 0.86 0.18 0.31 -0.06 0.72 0.04 0.82 0.11 0.55 OP4 0.22 0.19 0.02 0.88 0.17 0.32 0.07 0.66 0.06 0.74 0.12 0.53 ICF 0.2 0.24 0.03 0.85 0.15 0.4 0.08 0.62 0.11 0.57 0.13 0.48 ADEC 0.1 0.54 0.08 0.63 0.12 0.49 0.12 0.49 0.17 0.37 0.19 0.3 NRF -0.06 0.75 0.22 0.18 0.09 0.58 0.05 0.74 0.02 0.89 0.04 0.8 NPC -0.05 0.75 0.14 0.41 NPF -0.08 0.64 0.17 0.31 Pr ADEC-ICF 0.15 0.36 0.05 0.63 0.14 0.43 0.1 0.54 0.14 0.46 0.17 0.37 Pr ICF-NRF 0.04 0.82 0.16 0.34 0.13 0.48 0.07 0.68 0.06 0.75 0.08 0.65 Pr ADEC-NRF 0.0006 0.99 0.18 0.29 0.11 0.5 0.08 0.63 0.08 0.66 0.11 0.57 Pr3 ADEC- 0.06 0.73 0.14 0.4 0.13 0.47 0.08 0.61 0.09 0.62 0.15 0.57 ICF-NRF Sumatoria X1 0.13 0.43 0.08 0.61 0.15 0.4 0.04 0.79 0.04 0.83 0.07 0.68 Gr OP-ADEC 0.22 0.19 0.23 0.17 0.1 0.57 0.13 0.45 0.28 0.13 0.19 0.31 Gr OP-ICF 0.019 0.91 0.13 0.42 0.03 0.8 0.06 0.7 0.14 0.44 0.05 0.77 Gr OP-NRF 0.24 0.15 0.32 0.06 0.003 0.98 0.02 0.86 0.0012 0.99 0.02 0.88 Gr OP-Pr 0.25 0.38 0.22 0.19 0.08 0.63 0.12 0.43 0.25 0.17 0.14 0.44 ADEC-ICF Gr OP-Pr ICF- 0.21 0.23 0.3 0.07 0.01 0.94 0.04 0.8 0.04 0.81 0.007 0.97 NRF Gr OP-Pr 0.25 0.13 0.32 0.06 0.03 0.86 0.06 0.72 0.08 0.67 0.03 0.87 ADEC-NRF Gr3 OP-Pr 0.23 0.18 0.31 0.07 0.03 0.83 0.06 0.69 0.11 0.57 0.04 0.83 ADEC-ICF- NRF
[0082] Chart 4 shows the correlation between the Pearson Test for different hemodynamic variables, namely: TAM, systemic arterial pressure; TAM-CVP, pressure gradient between both of them; Pw, pulmonary artery occlusion pressure; CF, cardiac frequency; LVSWI, left ventricle systolic work index; SVRWI, right ventricle systolic work index.
TABLE-US-00005 Pearson's test Systemic Vascular Resistance Temperature r2-Total r2- points population p r2-Awake p Sleeping p OP 0.29 0.08 0.025 0.9 0.91 0.0006 OP4 0.31 0.06 0.05 0.8 0.91 0.0006 ICF 0.35 0.036 0.07 0.73 0.93 0.0002 ADEC 0.44 0.008 0.28 0.16 0.89 0.0012 NRF 0.35 0.037 0.28 0.16 0.91 0.0008 NPC 0.45 0.0064 0.42 0.031 0.73 0.024 NPF 0.44 0.007 0.44 0.025 0.69 0.036 Pr ADEC-ICF 0.41 0.014 0.18 0.37 0.93 0.0002 Pr ICF-NRF 0.37 0.025 0.22 0.28 0.93 0.0002 Pr ADEC-NRF 0.4 0.016 0.29 0.14 0.9 0.0008 Pr3 ADEC-ICF-NRF 0.4 0.016 0.24 0.23 0.93 0.0003 Suma X1 0.37 0.03 0.14 0.47 0.91 0.0007 Gr OP-ADEC 0.32 0.053 0.45 0.021 0.19 0.61 Gr OP-ICF 0.17 0.32 0.11 0.57 0.12 0.75 Gr OP-NRF 0.24 0.16 0.31 0.12 0.62 0.07 Gr OP-Pr ADEC- 0.3 0.07 0.35 0.07 0.023 0.95 ICF Gr OP-Pr ICF-NRF 0.25 0.14 0.28 0.16 0.36 0.33 Gr OP-Pr ADEC- 0.28 0.09 0.37 0.06 0.32 0.39 NRF Gr3 OP-Pr ADEC- 0.28 0.09 0.34 0.08 0.24 0.52 ICF-NRF Spearman's Test Systemic Vascular Resistance Temperature r2-Total r2- points population p r2-Awake p Sleeping p OP 0.22 0.19 0.13 0.51 0.82 0.0058 OP4 0.25 0.14 0.16 0.42 0.85 0.0037 ICF 0.22 0.18 0.017 0.93 0.9 0.0009 ADEC 0.32 0.053 0.26 0.19 0.82 0.007 NRF 0.33 0.051 0.28 0.16 0.82 0.007 NPC 0.44 0.0087 0.45 0.019 0.58 0.09 NPF 0.4 0.016 0.44 0.023 0.43 0.24 Pr ADEC-ICF 0.27 0.11 0.12 0.56 0.92 0.0005 Pr ICF-NRF 0.28 0.09 0.19 0.33 0.92 0.0005 Pr ADEC-NRF 0.32 0.056 0.25 0.21 0.82 0.007 Pr3 ADEC-ICF-NRF 0.32 0.06 0.21 0.29 0.92 0.0005 Suma X1 0.26 0.12 0.11 0.58 0.92 0.0005 Gr OP-ADEC 0.3 0.07 0.4 0.039 0.28 0.46 Gr OP-ICF 0.08 0.6 0.004 0.98 0.16 0.67 Gr OP-NRF 0.28 0.09 0.31 0.11 0.4 0.28 Gr OP-Pr ADEC- 0.26 0.12 0.27 0.17 0.016 0.96 ICF Gr OP-Pr ICF-NRF 0.25 0.13 0.26 0.19 0.18 0.63 Gr OP-Pr ADEC- 0.32 0.06 0.38 0.052 0.06 0.86 NRF Gr3 OP-Pr ADEC- 0.29 0.08 0.32 0.11 0.26 0.6 ICF-NRF
[0083] Chart 5 shows the correlation between Pearson Test and Spearman Test for the Systemic Vascular Resistance (SVR).
[0084] Thus, it was found that only a few thermal spots of the face can suitably predict the hemodynamic variables of interest, i.e. CI and SVR, the same occurs with the thermal gradients. Likewise, it was found that the thermal spots and gradients to be taken into account will be different according to the specific situation of the patient: whether the patient is asleep or awake, under the influence of vasodilating or vasoconstrictor drugs, the PVC values and gender of the patient.
[0085] In conclusion, it could be said that specific thermal spots and gradients exist in the face of the patients and these spots and gradients are directly and indirectly correlated with CI and SVR.
[0086] Both the aforementioned FIRST and SECOND investigations prove the existence of specific spots on the skin of the face and the hand, as well as thermal gradients, which are related to cardiovascular performance. The best and highest correlations as valuated by the Spearman and Pearson Tests were employed for the computational algorithms, based on ML techniques for the development of the two modalities of the invention.
Function, Modality A
[0087] The invention described herein, by capturing thermal images from the face and the hand of the patient with any camera that can measure infrared radiation, allows for the prediction of the distance (in meters) which would be completed by the patient if subjected to a 6MWT. This method (6MWT) could be considered as a surrogate for detailed assessment of the reaction of the respiratory, cardiovascular, metabolic, musculoskeletal and neurosensorial systems of the patient subjected to the strain caused by physical exercise. As a consequence, it is one of the most utilized tools for this purpose in individuals with cardiac and respiratory diseases.
[0088] With the object of replacing tests such as the aforementioned, and with the purpose of reducing the time taken for testing the patient without the necessity for specialized personnel and with the capacity to perform it at any time or place, the invention evaluates a series of thermal parameters which, along with other general data from the patient, brings high-correlativity results in a simple and immediate fashion.
[0089] The computational algorithm analyses an average of three thermal photos from the front and profile of the face and the palm of the hand of the patient to be tested.
[0090] Hot and cold spots identified in the thermal images are employed. These thermal spots were located and studied following scientific investigation of the aforementioned first and second modalities. The thermal data of spots and gradients is integrated for the analysis along with data of clinical and non-clinical values also previously tested and selected, such as age, gender, size, weight, cardiac frequency, oxygen saturation, PH type, humidity and room temperature.
[0091] The thermal spots employed are the following: [0092] Head, front: the hottest spot in both ocular regions and the coldest spot of the nasal region. [0093] Head, profile: the hottest spot obtained from the area of the external auditive conduct, hottest spot in the Pterion region and the coldest obtained spot from the auricular pavilion.
[0094] Palm of the hand: hottest spot of the wrist, hottest spot of the center of the palm, hottest spots from the five fingertips.
[0095] The program employs a predictive model, which was developed employing ML techniques that allow us to establish the distance that could be walked by the patient if subjected to a 6MWT, expressed in meters.
[0096] In this case, after analyzing and employing several algorithms, the final algorithm selected to analyze the data and predict new entries was Fast Tree Regression Binary. With this algorithm it was possible to obtain the best result from the set of analyzed data.
[0097] The tool and library employed to perform these calculations was Microsoft ML (ML.NET Model Builderhttps://dotnet.microsoft.com/apps/machinelearning-ai/ml-dotnet/model-builder). This tool and library allow an agile analysis with Visual Studio, since it contains tools which allow us to obtain faster results with the available algorithms. The best result was obtained with the following parameters: [0098] Number of leaves: 7 [0099] Minimum Example Count Per Leaf: 10 [0100] Number of Trees =100 [0101] Learning Rate: 0.1602678f [0102] Shrinkage: 0.6471589f [0103] Bagging Example Fraction: 0 [0104] Best Step Ranking Regression Trees: true
[0105] These parameters are normally provided by the library, but in some cases, we've modified them in order to obtain a better prediction. These are the libraries used to develop these modules: [0106] Microsoft.ML, version: 1.3.1 [0107] Microsoft.ML.FastTree, version: 1.3.1
[0108] This is the main piece of code to resolve this module (to see with a better format, see the
TABLE-US-00006 public static IEstimator<ITransformer> BuildTrainingPipeline (MLContext mlContext) { / / Data process configuration with pipeline data transformations var inputColumnNames = ColumnNames ForModel Input ( ); var dpp = mlContext.Transforms.Conversion.ConvertType (new[ ] { new InputOutputColumnPair (HTA, HTA), new InputOutputColumnPair (HTA_DBT, HTA_DBT), new InputOutputColumnPair (DBT, DBT), new InputOutputColumnPair (IFDE_5, IFDE_5), new InputOutputColumnPair (PG, PG), new InputOutputColumnPair (BLOQ_CA, BLOQ_CA), new InputOutputColumnPair (IECA_ARA2, IECA_ARA2) }) .Append (mlContext.Transforms.Categorical.OneHotEncoding (new [ ] { new InputOutputColumnPair (Sexo, Sexo), new InputOutputColumnPair (SujetoDeEstodio, SujetoDeEstodio), new InputOutputColumnPair (TipoHP, TipoHP), new InputOutputColumnPair (ERA, ERA) })) .Append (mlContext.Transforms.Concatenate (Features, inputColumnNames)); / / Set the training algorithm var trainer = mlContext.Regression.Trainers.FastTree (new FastTreeRegressionTrainer.Options ( ) { NumberOfLeaves = 7, MinimumExampleCountPerLeaf = 10, NumberOfTrees = 100, LearningRate = 0.1602678f, Shrinkage = 0.6471589f, LabelColumnName = CF, FeatureColumnName = Features, BaggingExampleFraction = 0, BestStepRankingRegressionTrees = true, / /un poco mejor }); var trainingPipeline = dpp.Append (trainer); return trainingPipeline; }
[0109] The obtained model was employed to evaluate data from new testing. It can be employed for applications in different platforms, such as mobile devices, the web, etc. By uploading the aforementioned data, an immediate result is obtained (see
Function, Modality B
[0110] By employing the same principle as explained previously, the invention can estimate the CI and the SVR of a patient, when knowledge of the hemodynamic state is required, without resorting to an invasive method such as, for example, the Swan-Ganz catheter.
[0111] The thermal spots of reference were found through testing hospitalized patients in a Critical Care Unit. They required invasive hemodynamic monitoring employing the Swan-Ganz catheter, and more than 17 thermal spots of their faces were tested, along with averages of 7 anatomic regions, 3 different ways of averaging the distinctive thermal spots and 15 distinctive thermal gradients.
[0112] The thermal values that showed a better result when correlated with the CI and the SVR obtained through Swan-Ganz were integrated for analysis along with data from clinical and non-clinical values, already tested in anticipation and selected throughout the trials and research previously mentioned. This additional data encompasses: gender; exact PVC value as measured by a central venous catheter or approximation, demonstrated through the display of the external jugular vein ingurgement; usage or not of vasodilating or vasoconstrictor intravenous drugs; waking state of the patientwhether the patient is awake or pharmacologically asleep; humidity and room temperature.
[0113] The thermal spots employed in the computational algorithm for prediction are: the spot with the highest temperature in the interciliar region (ICF), the spot with the lowest temperature in the region of the root of the nose (NRF), the spot with the highest temperature of the inferior part of the dihedral angle, formed by the nasal wing and the infraorbitrary region (ADEC), and the averages and gradients between them.
[0114] The Modality B of the invention avoids the employment of invasive methods such as a catheter in a pulmonary artery, intra-arterial catheters, etc., that imply risks for the patient and are complex in their implementation, since they demand expertise and experience from the professionals. The Modality B is a fast and simple method that doesn't demand qualified personnel; moreover, it is harmless since it is a non-invasive method. It can be performed at any moment, anywhere.
[0115] The Modality B employs thermal and non-thermal data (as previously explained), integrating them in two predictive models which are different from those of Modality A, which were developed employing ML techniques.
[0116] Utilizing the same tools for analysis as Modality A, a new data set was considered. In this case a classifying algorithm was employed for the analysis of prediction of the new data set.
[0117] In this set of data, the objective was to predict the Cardiac Index and Systemic Vascular Resistance. It is worth mentioning that both variables to be predicted were calculated as binary variables; the cut-off points taken into account were: CI 2.5 liters/min/m.sup.2 and SVR 1000 dines/sec.cm.sup.5.
[0118] For the first step, Cardiac Index, the algorithm that provided the best results was One-Versus-All (OVA). This algorithm, with the libraries employed, required a standardized parametrization, describing the data entry and the data to be predicted.
[0119] For the second case, Systemic Vascular Resistance, the algorithm that got closer to predicting the results was Light Gbm.
[0120] These are the libraries used to develop these modules: [0121] Microsoft.ML, version: 1.5.0-preview [0122] Microsoft.ML.FastTree, version: 1.5.0-preview [0123] Microsoft.ML.LightGBM, version: 1.5.0-preview
[0124] These are the two main pieces of code to resolve these modules: [0125] For One-Versus-All (OVA). This is the main piece of code to resolve this module (to see with a better format, see the
TABLE-US-00007 public static IEstimator<ITransformer> BuildTrainingPipeline (MLContext mlContext) { // Data process configuration with pipeline data transformations var dpp = mlContext.Transforms.Conversion.MapValueToKey (Y_IC_Binario, Y_IC_Binario) .Append(mlContext.Transforms.Concatenate (Features, new [ ] { X_Sexo, X_PVC, X_Drogas_Binario, X_1_vs_2, X_OP, X_ICF, X_ADEC, X_NRF, X_Pr3_ADEC_ICF_NRF, X_Gr_OP_ADEC, X_Gr_OP_PrADEC_ICF })) .AppendCacheCheckpoint (mlContext); // Set the training algorithm var trainer = mlContext.MulticlassClassification.Trainers.OneVersusAll (mlCon text.BinaryClassification.Trainers.FastTree (labelColumnName: Y_IC_Binario, featureColumnName: Features) , labelColumnName: Y_IC_Binario) .Append (mlContext.Transforms.Conversion.MapKeyToValue (Predict edLabel, PredictedLabel)); var trainingPipeline = dpp.Append (trainer); return trainingPipeline; }
[0126] For Light Gbm. This is the main piece of code to resolve this module (to see with a better format, see the
TABLE-US-00008 public static IEstimator<ITransformer> BuildTrainingPipeline (MLContext mlContext) { // Data process configuration with pipeline data transformations var dpp = mlContext.Transforms.Conversion.MapValueToKey (Y_RVS_Binario, Y_RVS_Binario) .Append(mlContext.Transforms.Concatenate (Features, new [ ] { X_Sexo, X_PVC, X_Drogas_Binario, X_1_vs_2, X_OP, X_ICF, X_ADEC, X_NRF, X_Pr3_ADEC_ICF_NRF, X_Gr_OP_ADEC, X_Gr_OP_PrADEC_ICF })); / / Set the training algorithm var trainer = mlContext.MulticlassClassification.Trainers .LightGbm (labelColumnName: Y_RVS_Binario, featureColumnName: Features) .Append (mlContext.Transforms.Conversion .MapKeyToValue (PredictedLabel, PredictedLabel)); var trainingPipeline = dpp.Append (trainer); return trainingPipeline; }
[0127] By doing so, it allows us to establish (1) CI and (2) SVR from the patient to be tested in a simple, safe and immediate way.
[0128] Obtained resultsThe demonstrated value of the technology in different health care environments and different interested parties, as appropriate.
[0129] Modality A: a prospective validation was performed, 6MWT versus invention, Modality A, in controls and patients with Pulmonary Hypertension (PH); 121 cases. The multiple lineal regression analysis showed a statistically significant R square (See
[0130] The Bland-Altman plot showed a good agreement between the 6MWT and invention, Modality A. Sensitivity 91.3%, specificity 89.8%, PPV 67.7% and NPV 97.7%.
[0131] In patients who walk less than 440 meters, the area under the ROC curve shows a compelling diagnostic performance of the test and high accuracy (ROC curve=0.9497). (Refer to
[0132] This is important, because the value of 440 meters is a breakpoint between a good and a bad prognosis for patients with PH.
[0133] When the predictive power of the invention, Modality A is compared versus the Gibbons equation, which is based on age, weigh, high, gender, which is usually used to predict walking distance in healthy people, it was found that in healthy patients, the correlation was very similar to that shown in the Gibbons plot. (Refer to
[0134] However, when patients with PH are analyzed and the predictive equation of Gibbons is applied, then the correlation is less accurate. In contrast, when the invention is used, Modality A, the correlation is much higher, being that of 0.66. (See
[0135] Modality B: The properties of the invention, Modality B, were calculated in values of sensitivity, specificity, negative predictive value and positive predictive value to detect heart failure, using the Swan-Ganz catheter and thermodilution as reference methods.
[0136] Sensitivity, Specificity, Positive Predictive Value, and Negative Predictive Value were calculated. The Receiver Operating Characteristic (ROC) curve of the aforementioned method was also plotted. Heart failure was defined as a CI<2.5 liter/min/m.sup.2 measured by thermodilution method and Swan-Ganz catheter. A value of p<0.05 was considered significant. A transverse-sectional and prospective recruitment study was conducted. 35 hemodynamic measurements were conducted in 18 patients who were under hospitalization in a Cardiovascular Critic Care Unit for different reasons which required invasive hemodynamic monitoring, using Swan-Ganz catheter.
[0137] The usual invasive hemodynamic variables were recorded including CI, SVR and PVC. The Modality B test was performed at the same time as each thermodilution measurement using a Swan-Ganz catheter.
[0138] The results were as follows: at the moment of taking measurements by Swan-Ganz, 52% of the patients suffered from cardiac insufficiency and 49% at the moment of employing the invention, Modality B. The invention, Modality B presented a Reliability (Accuracy)=72.2% for testing cardiac insufficiency. [0139] Sensitivity=72.2 (CI95% 51.5 to 92.8) [0140] Specificity=72.2 (CI95% 51.5 to 93.2) [0141] VPP=72.2 (CI95% 51.5 to 92.8) [0142] VPN=57 (CI95% 20.3 to 93.7) [0143] Area under the ROC curve 0.619 (See
Practical Implementation
[0144] It is a surrogate method to measure the hemodynamic state and the effort capacity of the patient, the result is immediate, easy to use at any time and any place, and it does not require skill in its use, which allows it to be used by any professional, nurse or health technician.
[0145] Its versatility would allow it to be used, under appropriate conditions, both in Critical Care Units, outpatient medical offices and even by the patient themselves at home subject to the availability of the right elements and under the right conditions.
[0146] It could avoid the need for the use of invasive methods and their complications by being used as a screening method in patients where there are doubts about whether or not to use invasive methods.
Additional Utilities
[0147] 1. The invention can be correlated to invasive methods, it can predict CI and SVR. But by modifying the employed computational algorithm it could predict the congestive state of a patient with cardiac failure in the right or left ventricle, since we find statistically significant correlations with the Pearson and Spearman Tests between certain thermal spots and gradients, with the PVC value measured through an invasive method such as Swan-Ganz catheter. [0148] 2. Considering the characteristics of the method and the physiological principle of its function, the invention could have its own predictive value for mortality or morbimortality, independently from that of the traditional testing methods, for example, the Cardiopulmonary Effort Test with measurement of oxygen consumption. For this purpose, it requires testing in a prospective trial with the appropriate sample quantity. [0149] 3. The computational algorithm for evaluation and analysis of thermal images can be used in telemedicine. This allows patients treated or studied in one place to be treated or tested elsewhere by another health care professional who is not physically present with the patient. This also allows patients to be evaluated at home and without medical presence, a method called selfie mode. [0150] 4. By means of testing of a larger number of individuals (patients), the invention could have a more suitable algorithm, which would allow it to predict an approximate value of CI and SVR as a continuous variable, and not only provide a dichotomous result of sick or healthy, high or low value.
IMPLEMENTATION EXAMPLES
Clinical Case 1; Patient L. G.:
[0151] Male, 71, undergoing hospitalization in Coronary Unit due to Cardiogenic Shock in context of valvular dilated myocardiopathy with severe left ventricle function deterioration. This required invasive hemodynamic management, with Swan-Ganz catheter and treatment with inotropes and vasodilators.
[0152] Measurements were made with the invention according to Modality B, prior to measurement by thermodilution with a Swan-Ganz catheter, at three different points in its evolution. (see
1.SUP.st .Measurement:
[0153] Data involved: room temperature 22 C., room humidity 57%; PVC Value 11 mmHg; Male; waking state; Vasoactive drugs employed: dobutamine and milrinone. [0154] Result according to the method of the invention, Modality B, patient with heart failure. [0155] Result according to the Swan-Ganz method: CI=1.85 liters/min/m.sup.2.
2.SUP.nd .Measurement:
[0156] Data involved: room temperature 22.1 C.; ambient humidity 55%; PVC value 7 mmHg; Male; Waking state; Vasoactive drugs used: dobutamine, milrinone and sodium nitroprusside. [0157] Result according to the method of the invention, Modality B: patient without heart failure. [0158] Result according to Swan-Ganz: IC=2.9 liters/min/m.sup.2.
3.SUP.rd .Measurement:
[0159] Data involved: room temperature 22.5 C.; ambient humidity: 58%; PVC Value 6mmHg; Male; Waking state; Vasoactive drugs used: dobutamine, milrinone and sodium nitroprusside. [0160] Result according to the method of the invention, Modality B: patient without heart failure. [0161] Result according to Swan-Ganz: CI=2.97 liters/min/m.sup.2.
Clinical Case 2; Patient H. B.:
[0162] 25-year-old female, carrier of Group 1 Pulmonary Hypertension, idiopathic, in functional class 2, NT-proBNP 839 pg/ml, with a weight of 63 kg and height of 165 cm. Treated with a specific combined therapy for Pulmonary Hypertension: sildenafil, macitentan and treprostinil. (See
[0163] Data involved according to the method of the invention, Modality A: Weight 63 kg.; Height165 cm; SexFemale ; Age25 years; PH Type: idiopathic; Functional Class 2; Treatment with 3 particular drugs; Oxygen saturation in blood 97% and Cardiac frequency 78min; Systolic Arterial pressure 112 mmHg, diastolic: 76 mmHg; Room temperature 24.7 C.; ambient humidity 61%.
Results
[0164] Predicted distance by Gibbons equation=554 m [0165] Real distance walked in 6MWT=450 m [0166] Predicted distance according to the method of the invention, Modality A=462 m
Clinical Case 3; Patient C. C. S.:
[0167] 62-year-old man, undergoing hospitalization in Coronary Unit due to Cardiogenic Shock in the context of post-operative cardiac surgery with severe left ventricular function deterioration. Invasive hemodynamic monitoring with Swan-Ganz catheter and treatment with inotropics and vasoconstrictors were required.
[0168] Measurements were taken with the invention according to Modality B, before proceeding with measurements by thermodilution with a Swan-Ganz catheter, in two different moments of its process. (See
1.SUP.st .Measurement:
[0169] Data involved: Room temperature 23.7; Ambient humidity 38%; PVC value 9 mmHg; male; state of pharmacological sedation in ARM; vasoactive drugs used: dobutamine, norepinephrine, epinephrine, phenylephrine, vasopressin and methyl blue. [0170] Result according to the method of the invention, Modality B, patient with heart failure. High SVR. [0171] Result according to Swan-Ganz: CI=2.1 liters/min/m.sup.2. SVR=1065 dines/sec.cm.sup.5.
2.SUP.nd .Measurement:
[0172] Data involved: room temperature 26.1; ambient humidity 26%; PVC value 11 mmHg; Male; State of pharmacological sedation in ARM; Vasoactive drugs used: norepinephrine and epinephrine. [0173] Result according to the method of the invention, Modality B, patient without heart failure. Reduced SVR. [0174] Result according to Swan-Ganz: CI=3.5 liters/min/m.sup.2, SVR=657 dines/sec.cm.sup.5.