# US 10,765,377 B2 · Heartbeat-signal detecting device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,765,377 B2 - Document ID: US10765377B2 - Status: Granted - Kind: B2 - Application number: 15/548,286 - Filed: 2016-02-03 - Published: 2018-01-18 - Granted: 2020-09-08 - Earliest claimed: 2015-02-03 - Assignees: National University Corporation Tokai National Higher Education and Research System - Applicants: National University Corporation Tokai National Higher Education - Inventors: Tsutomu Kawabe; Mitsuhiro Shikida; Miyoko Matsushima - Web page: https://patentgrep.com/patent/US10765377B2 ## CPC - A61B 5/7278: {Artificial waveform generation or derivation, e.g. synthesizing signals from measured signals} - A61B 1/2676: {Bronchoscopes} - A61B 1/273: for the upper alimentary canal, e.g. oesophagoscopes or gastroscopes - A61B 5/024: Measuring pulse rate or heart rate - A61B 5/0245: by using sensing means generating electric signals, {i.e. ECG signals} - A61B 5/087: Measuring breath flow - A61B 5/6803: {Head-worn items, e.g. helmets, masks, headphones or goggles} - A61B 5/6852: {Catheters} - A61B 5/7257: {using Fourier transforms} - G01F 1/68: by using thermal effects - G01F 1/69: of resistive type - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME ## Abstract A heartbeat-signal detecting device, which is for detecting a heartbeat signal of a living body, includes: (a) a gas-flow sensor configured to detect a flow rate of exhalation and inhalation passing through a trachea of the living body; (b) a gas-flow calculation controlling portion configured to output a respiration signal that reflects a respiratory motion of the living body, based on a signal outputted from the gas-flow sensor; (c) a waveform analysis controlling portion configured to extract, from the respiration signal, frequency components which are in synchronization with a pulse of a heart of the living body superimposed on the respiration signal, and to output a heartbeat signal representing a heartbeat waveform of the living body; and (d) a heartbeat-signal evaluation controlling portion is configured to evaluate a functional abnormality or an anatomic abnormality of the heart, based on the heartbeat signal analyzed by the waveform analysis controlling portion. ## Claims ### Claim 1 A heartbeat-signal detecting device for detecting a heartbeat signal of a living body, said heartbeat-signal detecting device comprising: a gas-flow sensor configured to detect a flow rate of exhalation and inhalation passing through a trachea of the living body in a state in which an artificial respirator is not provided; a gas-flow calculation controlling portion configured to output a cyclic respiration signal that reflects a respiratory motion of the living body, based on a signal outputted from said gas-flow sensor; a waveform analysis controlling portion configured to extract, from the cyclic respiration signal outputted from said gas-flow calculation controlling portion, a plurality of frequency components which are in synchronization with a pulse of a heart of the living body superimposed on the cyclic respiration signal, and to output a heartbeat signal representing a heartbeat waveform of the living body, from the plurality of frequency components; and a heartbeat-signal evaluation controlling portion configured to evaluate a functional abnormality or an anatomic abnormality of the heart, based on the heartbeat signal analyzed by said waveform analysis controlling portion, wherein said gas-flow sensor is further configured to detect a flow speed of a gas passing through a tube, based on a change of an electric resistance of a heater element that is heated by electricity supplied thereto, the electric resistance being changed depending on the flow speed, said heater element being constituted by an electric resistance element whose electric resistance is changed depending on a temperature, said heater element being provided on an inner surface of a circuit substrate film which is disposed in said tube and which is spaced apart from said tube a predetermined space. ### Claim 2 (depends on 1) The heartbeat-signal detecting device according to claim 1, wherein said gas-flow sensor is provided in a mask covering a nose and a mouth of the living body, or an endotracheal intubation tube inserted into the trachea of the living body. ### Claim 3 (depends on 1) The heartbeat-signal detecting device according to claim 1, wherein the circuit substrate film is disposed along an inner wall surface of said tube and which is spaced apart from said inner wall surface by the predetermined space. ### Claim 4 (depends on 3) The heartbeat-signal detecting device according to claim 3, comprising: a gas-flow-speed measuring circuit including a bridge circuit that includes four resistance elements, each of one or two of said four resistance elements being constituted by said heater element; and wherein said gas-flow calculation controlling portion is configured to calculate the flow rate or the flow speed in accordance with a pre-stored relationship between the flow rate or the flow speed and an output signal of said gas-flow-speed measuring circuit that reflects a resistance value of said heater element, and based on the output signal of said gas-flow-speed measuring circuit. ### Claim 5 (depends on 1) The heartbeat-signal detecting device according to claim 1, wherein said waveform analysis controlling portion is configured to remove, from the cyclic respiration signal outputted from said gas-flow calculation controlling portion, the frequency components which are in synchronization with the pulse of the heart of the living body superimposed on the cyclic respiration signal, and output a ventilation component signal representing a lung capacity component originating from a thorax and a thoracic diaphragm of the living body. ### Claim 6 (depends on 1) The heartbeat-signal detecting device according to claim 1, wherein said waveform analysis controlling portion is configured to extract, by means of Fourier transform, the plurality of frequency components that are in synchronization with the pulse of the heart superimposed on the cyclic respiration signal outputted from said gas-flow calculation controlling portion, and to compose, by means of inverse Fourier transform, the heartbeat signal from the plurality of frequency components. ### Claim 7 (depends on 1) The heartbeat-signal detecting device according to claim 1, wherein: the cyclic respiration signal represents a cyclic change of the flow rate that is in synchronization with respiration of the living body, and the heartbeat waveform represented by the heartbeat signal has a fundamental frequency higher than that of a respiratory waveform represented by the cyclic respiration signal and is superimposed on the respiratory waveform represented by the cyclic respiration signal.