Heart monitors and processes with accelerometer motion artifact cancellation, and other electronic systems

Abstract

A heart monitor includes a single chest accelerometer (210), an analog signal conditioning and sampling section (215) responsive to said accelerometer to produce a digital signal substantially representing acceleration, and a digital processor (220) operable to filter the acceleration signal into a signal affected by body motion and to cancel the body motion signal from the acceleration signal, thereby to produce an acceleration-based cardiac-related signal. Other processes and electronic systems are also disclosed.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This application is related to U.S. patent applications as follows:[0002]This application is related to U.S. patent application “Motion / Activity, Heart-Rate and Respiration From a Single Chest-Worn Sensor” Ser. No. 12 / ______ (TI-68552) filed Aug. 24, 2010 simultaneously herewith, for which priority is claimed under 35 U.S.C. 120 and all other applicable law, and which is incorporated herein by reference in its entirety.[0003]This application is related to U.S. patent application “Estimation Of Blood Flow And Hemodynamic Parameters From A Single Chest-Worn Sensor, And Other Circuits, Devices And Processes” Ser. No. 12 / ______ (TI-68553) filed Aug. 24, 2010 simultaneously herewith, for which priority is claimed under 35 U.S.C. 120 and all other applicable law, and which is incorporated herein by reference in its entirety.[0004]This application is related to provisional U.S. patent application “Motion Artifact Cancellation to Obtain Heart So...

AI Technical Summary

Benefits of technology

[0032]Generally, and in a further form of the invention, an electronic signal processing system includes a streaming data interface, a nonvolatile memory holding instructions representing a filtering process and coefficients, and an electronic processor coupled to the nonvolatile memory to operate in accordance with the instructions, the processor having an input coupled to the streaming data interface for a streaming data signal including noise and operable to digitally electronically execute a smoothing-filter-based procedure on the streaming data signal by a multiply-accumulation with at least some of the coefficients stored in the nonvolatile memory, the coefficients and procedure of a type adapted to reduce the noise and to largely remove slow variations thereby to produce a residue stream, the streaming data interface having an output for a signal based on the residue stream.

Problems solved by technology

Most current solutions for heart rate monitoring involve cumbersome equipment, such as heart rate recording belts to be worn around the chest, electrocardiogram (ECG) electrodes and leads, and in most cases electrical contact to the skin.

However, such methods remain obtrusive, and are not optimal for long-term and ambulatory monitoring.

Current solutions for not only heart rate monitoring but also respiration monitoring are believed to involve cumbersome and expensive equipment e.g., respiration and heart rate monitoring belts to be worn around the chest, spirometers and canulas to be worn around the mouth and nose, and electrocardiogram (ECG) electrodes and leads to be taped on the body.

Not only are these solutions obtrusive and expensive, but may also be too restrictive to be well-suited for ambulatory monitoring.

Noise mixed with signals received by the sensors used in heart monitoring, respiration monitoring, body motion and other monitoring applications can adversely affect the accuracy of each type of signal.

Such arrangements are very difficult to establish in a real setting and can cause poor rejection of the motion signal and body motion artifacts.

Some conventional single-channel de-noising techniques reinforce all major signal peaks and fail to distinguish body motions from heart sounds.

Hemodynamic data also challenge the art to find methods and devices for obtaining, isolating, determining and monitoring more simply, economically and more efficiently.

Most current solutions for the measurement of blood flow and other hemodynamic parameters are believed to involve cumbersome and expensive equipment e.g., Impedance Cardiography (calls for electrodes to be connected on the skin), Doppler Echo Cardiography, Continuous Blood Pressure Monitoring etc.

Not only are these solutions obtrusive and expensive, but may also be too restrictive to be well-suited for ambulatory monitoring applications.

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