# US 11,992,336 B2 · Device, system and method for generating biofeedback > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,992,336 B2 - Document ID: US11992336B2 - Status: Granted - Kind: B2 - Application number: 16/474,857 - Filed: 2017-12-21 - Published: 2021-01-07 - Granted: 2024-05-28 - Earliest claimed: 2016-12-29 - Assignees: Thomas Mengden; Ait Austrian Institute of Technology GmbH - Applicants: Ait Austrian Institute of Technology GmbH; Thomas Mengden - Inventors: Thomas Mengden; Siegfried Wassertheurer - Web page: https://patentgrep.com/patent/US11992336B2 ## CPC - A61B 5/486: {Biofeedback (using electroencephalography [EEG] A61B5/375)} - A61B 5/02028: {Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction} - A61B 5/02125: {of pulse wave propagation time} - A61B 5/02405: {Determining heart rate variability} - A61B 5/029: Measuring blood output from the heart, e.g. minute volume - A61B 5/165: {Evaluating the state of mind, e.g. depression, anxiety} - A61B 5/4035: {Evaluating the autonomic nervous system} - A61B 5/4836: {Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence)} - A61B 5/7239: {using differentiation including higher order derivatives} - A61B 5/742: {using visual displays (displays for heart-related electrical signals, e.g. ECG, A61B5/339)} - A61B 5/002: {Monitoring the patient using a local or closed circuit, e.g. in a room or building (A61B5/0017 takes precedence)} - A61B 5/0261: {using optical means, e.g. infrared light} - A61B 5/0816: {Measuring devices for examining respiratory frequency (measuring frequency of electric signals G01R23/00)} - A61B 5/6803: {Head-worn items, e.g. helmets, masks, headphones or goggles} - A61B 5/6898: {Portable consumer electronic devices, e.g. music players, telephones, tablet computers} - A61B 5/7257: {using Fourier transforms} - A61B 2503/12: Healthy persons not otherwise provided for, e.g. subjects of a marketing survey - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract An apparatus for generating biofeedback, in particular during a relaxation exercise for lowering blood pressure, comprises at least one interface for receiving a pulse wave signal that represents a pressure pulse or volume pulse of a pulse wave in a blood circulation system as a function of time and an ECG signal. The apparatus comprises an evaluation device that is configured to determine a pulse transit time on the basis of the pulse wave signal and the ECG signal, perform an evaluation of a pulse wave form of the pulse wave signal and generate the biofeedback depending on the pulse transit time and/or the evaluation of the pulse wave form. The apparatus comprises an output interface for providing the biofeedback. ## Claims ### Claim 1 An apparatus for generating biofeedback, comprising: at least one interface for receiving a pulse wave signal, which represents a pressure pulse or volume pulse of a pulse wave in a blood circulation system as a function of time, and an ECG signal, the at least one interface being configured to synchronize data transmission and data acquisition between sensors that capture the pulse wave signal and the ECG signal, an evaluation device comprising an integrated semiconductor circuit that is configured to determine a pulse transit time on a basis of the pulse wave signal and the ECG signal, perform an evaluation of a pulse wave form of the pulse wave signal and generate the biofeedback depending on the pulse transit time and/or the evaluation of the pulse wave form, wherein the integrated semiconductor circuit of the evaluation device is configured to determine whether there is a change in blood pressure caused by vagus enhancement or sympathetic attenuation by comparison of the pulse wave form with a reference pulse wave form, and an output interface for providing the biofeedback and to indicate via the output interface whether there is a change in blood pressure caused by vagus enhancement or sympathetic attenuation which improves vegetative balance of a user of the apparatus, wherein the output interface is configured to output both the biofeedback and instructions for performing a relaxation exercise, wherein the instructions for performing the relaxation exercise are generated by the apparatus using a value of an adjustable parameter that depends on the pulse transit time and/or the evaluation of the pulse wave form. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein the evaluation device is configured to determine a mode of action underlying the change in blood pressure, a magnitude of the change in blood pressure and/or a change in pulse wave reflection by evaluating the pulse wave form. ### Claim 3 (depends on 1) The apparatus according to claim 1, wherein the evaluation device is configured to determine a change in afterload by evaluating the pulse wave form. ### Claim 4 (depends on 3) The apparatus according to claim 3, wherein the evaluation device is configured to output the change in afterload via the output interface. ### Claim 5 (depends on 3) The apparatus according to claim 3, wherein the evaluation device is configured to detect a change in at least one of the following variables in order to determine whether there is the change in blood pressure caused by vagus enhancement or sympathetic attenuation: duration of an early systolic phase; pressure in the early systolic phase; or duration of a late systolic phase. ### Claim 6 (depends on 1) The apparatus according to claim 1, wherein the evaluation device is configured to determine a change in cardiac pumping capacity by evaluating the pulse wave form. ### Claim 7 (depends on 1) The apparatus according to claim 1, wherein the evaluation device is configured to perform the respective determination of the pulse transit time and/or the respective evaluation of the pulse wave form for each cardiac cycle of a plurality of successive cardiac cycles. ### Claim 8 (depends on 7) The apparatus according to claim 7, wherein the apparatus is configured to output the respective biofeedback via the output interface for each cardiac cycle of the plurality of successive cardiac cycles. ### Claim 9 (depends on 1) The apparatus according to claim 1, wherein the biofeedback comprises at least one piece of information selected from the group consisting of: the change in blood pressure, blood pressure, cardiac pumping capacity, change in afterload, pulse wave reflection, or mode of action underlying the change in blood pressure. ### Claim 10 (depends on 1) The apparatus according to claim 1, wherein the output interface comprises an optical output unit, wherein the apparatus is configured to output the instructions for performing the relaxation exercise and the biofeedback at the same time via the optical output unit. ### Claim 11 (depends on 1) The apparatus according to claim 1, wherein the evaluation device is configured to determine the pulse transit time and/or at least one characteristic of the pulse wave form determined by the evaluation of the pulse wave form as a function of a parameter of the relaxation exercise. ### Claim 12 (depends on 1) The apparatus according to claim 1, wherein the apparatus is configured for generating the biofeedback during the relaxation exercise for lowering the blood pressure. ### Claim 13 A system, comprising: an apparatus for generating biofeedback, the apparatus comprising at least one interface for receiving a pulse wave signal, which represents a pressure pulse or volume pulse of a pulse wave in a blood circulation system as a function of time, and an ECG signal, the at least one interface being configured to synchronize data transmission and data acquisition between the pulse wave signal and the ECG signal, an evaluation device comprising an integrated semiconductor circuit that is configured to determine a pulse transit time on a basis of the pulse wave signal and the ECG signal, perform an evaluation of a pulse wave form of the pulse wave signal and generate the biofeedback depending on the pulse transit time and/or the evaluation of the pulse wave form, wherein the evaluation device is configured to determine whether there is a change in blood pressure caused by vagus enhancement or sympathetic attenuation by comparison of the pulse wave form with a reference pulse wave form, and an output interface for providing the biofeedback and to indicate via the output interface whether there is a change in blood pressure caused by vagus enhancement or sympathetic attenuation which improves vegetative balance of a user of the apparatus, wherein the output interface is configured to output both the biofeedback and instructions for performing a relaxation exercise, wherein the instructions for performing the relaxation exercise are generated by the apparatus using a value of an adjustable parameter that depends on the pulse transit time and/or the evaluation of the pulse wave form; and a sensor device which is couplable to said at least one interface of the apparatus and configured to detect the pulse wave signal and the ECG signal. ### Claim 14 (depends on 13) The system according to claim 13, wherein the sensor device comprises a first sensor for detecting the pulse wave signal and a second sensor for detecting the ECG signal. ### Claim 15 (depends on 13) The system according to claim 13, wherein the apparatus is configured for generating the biofeedback during the relaxation exercise for lowering the blood pressure. ### Claim 16 A method for generating biofeedback, comprising the steps of: receiving, by an apparatus, a pulse wave signal, which represents a pressure pulse or volume pulse of a pulse wave in a blood circulation system as a function of time, and an ECG signal by at least one interface, the at least one interface being configured to synchronize data transmission and data acquisition between sensors that capture the pulse wave signal and the ECG signal, determining, by the apparatus, a pulse transit time by evaluating the pulse wave signal and the ECG signal, evaluating, by the apparatus, a pulse wave form of the pulse wave signal to determine whether there is a change in blood pressure caused by vagus enhancement or sympathetic attenuation by comparison of the pulse wave form with a reference pulse wave form, generating, by the apparatus, the biofeedback depending on the pulse transit time and/or the evaluation of the pulse wave form, and outputting, by the apparatus, the biofeedback and instructions for performing a relaxation exercise and indicating via an output interface whether there is a change in blood pressure caused by vagus enhancement or sympathetic attenuation which improves vegetative balance of a user of the apparatus, wherein the instructions for performing the relaxation exercise are generated by the apparatus using a value of an adjustable parameter that depends on the pulse transit time and/or the evaluation of the pulse wave form. ### Claim 17 (depends on 16) The method according to claim 16, wherein the biofeedback is generated during the relaxation exercise for lowering the blood pressure. ### Claim 18 (depends on 17) The method according to claim 17, wherein the relaxation exercise comprises a breathing exercise. ### Claim 19 (depends on 16) The method according to claim 16, wherein the ECG signal is used both to determine the pulse transit time and to determine a heart rate variability. ### Claim 20 (depends on 16) The method according to claim 16, which is carried out by the apparatus for generating the biofeedback, the apparatus comprising: the at least one interface for receiving the pulse wave signal that represents the pressure pulse or volume pulse of the pulse wave in the blood circulation system as the function of time and the ECG signal; an evaluation device that is configured to determine the pulse transit time on the basis of the pulse wave signal and the ECG signal, perform the evaluation of the pulse wave form of the pulse wave signal and generate the biofeedback depending on the pulse transit time and/or the evaluation of the pulse wave form; and the output interface for providing the biofeedback.