An electrocardiogram system is provided. The system includes an array of sensors configured to generate electrical signals relating to cardiac activity. The system further includes a plurality of lead cables. Each lead cable includes a sensor terminal, an opposing sensor terminal, and an intermediate segment. The intermediate segment is interposed between the sensor terminal and the opposing sensor terminal. The array of sensors are electrically coupled to the sensor terminals. The intermediate segment is configured to carry the electrical signals from the sensor terminal to the opposing sensor terminal. The intermediate segment is enclosed by a non-conductive enclosure. The non-conductive enclosure having opposing linear surfaces and opposing lateral surfaces extending from the opposing linear surfaces. The opposing linear surfaces are parallel with respect to each other.

This disclosure provides cascaded reference circuits and low amplitude signal sensing circuits that are useful in wearable devices. Circuits for measuring electrovesselgram (EVG) and subdermal spectrogram (SSG) are provided, as well as methods for using these circuits to determine quantities and qualities of a person's moods, such as how much and what kinds of stress they experience. The provided devices are useful on limbs and appendages, such as in a smart watch that is worn on the wrist. Methods are provided for using the devices of this disclosure to privately alert wearers to an increase in bad stress in the moment when they can take actions to reduce their stress and physiological stress responses. These devices are useful for measuring and increasing the effectiveness of relaxation techniques. As a result of using methods and devices of this disclosure, people are healthier, they make more response-able decisions, and relationships improve.

A defibrillator having a pair of electrodes for delivering an artifact-compensated defibrillation shock and a method thereof is provided. The defibrillator can be deployed rapidly while administering a cardio-pulmonary resuscitation (CPR) on the patient. Upon detection of an end of the CPR operation, a correlation signal indicative of signal corruption is detected and analyzed rapidly to determine an appropriate energy level discharged across the pair of electrodes. Thereafter, a notification signal is sent to the user of the defibrillator prior to delivering the defibrillation shock to the patient. The artifact-compensated defibrillation shock is delivered if for a predetermined period of time no movement is detected.

One embodiment provides a system for determination and utilization of cardiac electrical asynchrony data. The system includes an analysis circuitry including a processor and a memory, the analysis circuitry configured to: obtain a plurality of sets of cardiac signals collected in at least two locations of a heart of a patient, the signals comprising at least one of surface electrocardiography signals and pseudo-surface ECG signals; detect one or more QRS complexes for each of the sets based on the cardiac signals for that set; obtain one or more cross-correlation signals, each of the cross-correlation signals being between at least two of the signal sets and being obtained using the detected QRS complexes from the signal sets; and calculate one or more asynchrony indices using one or more of the cross-correlation signals, each of the asynchrony indices being indicative of a level of asynchrony between the at least two locations.

An electrocardiogram (ECG) signal processing system is provided. The ECG signal processing system comprises an analog-to-digital converter (ADC) configured to convert an input analog ECG signal into a digital ECG signal, and a digital signal processing engine (DSPE) coupled to the ADC to receive the digital ECG signal. The DSPE is configured to decompose and reconstruct the digital ECG signal. A dynamic system clock source is coupled to the ADC and the DSPE for dynamic signal sampling, the dynamic system clock source clocking the ADC and the DSPE at a first frequency f1 to detect one or more first parameters of the input analog ECG signal and at a second frequency f2 to detect one or more second parameters of the input analog ECG signal.

A biological information measurement apparatus includes a phase/frequency comparison unit that outputs a deviation signal based on a phase difference between a biological signal and an oscillation signal; a loop filter; and a voltage controlled oscillation unit that generates the oscillation signal in accordance with the deviation signal that has passed through the loop filter. The apparatus further includes a CPU that estimates a SN ratio of the biological signal and analyzes a phase difference/frequency difference between the biological signal and the oscillation signal. A variable low pass filter is provided that selectively blocks a signal of a predetermined frequency band contained in the deviation signal that has passed through the loop filter and the CPU changes a cutoff frequency of the variable low pass filter based on the SN ratio and the phase difference/frequency difference.

A biological information measurement apparatus includes a phase/frequency comparison unit that outputs a deviation signal based on a phase difference between a biological signal and an oscillation signal; a variable loop filter that varies a cutoff frequency and a phase margin and that selectively blocks a signal of a predetermined frequency band contained in the deviation signal; and a voltage controlled oscillation unit that generates the oscillation signal in accordance with the deviation signal that has passed through the variable loop filter. The apparatus further includes a CPU that estimates a SN ratio of the biological signal and analyzes a phase difference/frequency difference between the biological signal outputted from the comparison unit and the oscillation signal. The CPU further changes a constant of the variable loop filter based on the SN ratio and the phase difference/frequency difference.

An adherent device to monitor a patient for an extended period comprises a breathable tape. The breathable tape comprises a porous material with an adhesive coating to adhere the breathable tape to a skin of the patient. At least one electrode is affixed to the breathable tape and capable of electrically coupling to a skin of the patient. A printed circuit board is connected to the breathable tape to support the printed circuit board with the breathable tape when the tape is adhered to the patient. Electronic components electrically are connected to the printed circuit board and coupled to the at least one electrode to measure physiologic signals of the patient. A breathable cover and/or an electronics housing is disposed over the circuit board and electronic components and connected to at least one of the electronics components, the printed circuit board or the breathable tape.

Devices and methods provide for the sensing of physiological signals during stimulation therapy by preventing stimulation waveform artifacts from being passed through to the amplification of the sensed physiological signal. Thus, the sensing amplifier is not adversely affected by the stimulation waveform and can provide for successful sensing of physiological signals. A common mode voltage is applied to the stimulation electrodes while sensing during a recharge period where the common mode voltage approximates the stimulation pulse being received at the sensing electrodes. This common mode voltage is determined based on measuring a common mode signal for at least one of the inputs of the amplifier or by deriving the proper common mode from monitoring the output signal of the amplifier to observe the elimination of artifacts during stimulation. Blanking switches may be used to blank the sensing of the peak of the recharge period should that peak be relatively large.

A front-end amplifier circuit for receiving a biological signal includes a signal channel. The signal channel amplifies the biological signal to generate a detection current and includes a capacitive-coupled transconductance amplifier. The capacitive-coupled transconductance amplifier amplifies the biological signal with a transconductance gain to generate a first current.