A Review of Methods for Non-Invasive Heart Rate Measurement on Wrist

Abstract

When evaluating general health condition on a patient, heart rate is an essential indicator as it is directly representative of the cardiac system state. Continuous measurement methods of heart rate are required for ambulatory monitoring involved in preliminary diagnostic indicators of cardiac diseases or stroke. The growing number of recent developments in wearable devices is reflective of the increasing demand in wrist-worn activity trackers for fitness and health applications. Indeed, the wrist represents a convenient location in terms of form factor and acceptability for patients. While most commercially-available devices are based on optical methods for heart rate measurement, others methods were also developed, based on various physiological phenomena. This review is focused on heart rate measurement methods located on forearm and more specifically on the wrist. For each method, the physiological mechanism involved is described, and the associated transducers for bio-signal acquisition as well as practical developments and prototypes are presented. Methods are discussed on their advantages, limitations and their suitability for an ambulatory use. More specifically, the superposition of motion artefacts over the signal of interest is one of the largest drawbacks for these methods, when used out of laboratory conditions. As such, artefact reduction techniques proposed in the literature are also presented and discussed.

Non-Invasive Physiological Monitoring for Physical Exertion and Fatigue Assessment in Military Personnel: A Systematic Review

“…The literature has evidenced how continuous methods of heart rate measurement are essential for preliminary diagnostic indicators of any form of cardiovascular risk (cardiac diseases or stroke) [78,79] resulting from intense, physically demanding situations. However, multiple factors can also influence increases in heart rate (stress, anxiety, body posture) without necessarily representing any health risk.…”

Real-Time PPG Signal Conditioning with Long Short-Term Memory (LSTM) Network for Wearable Devices

“…There are other methods of heart rate measurements, such as, for example, impedance-plethysmography, magneto-plethysmography, temperature-based methods, mechanical ballistocardiography, microwave ballistocardiography and ultrasound echocardiography. A review of these methods can be found in [ 6 ].…”

First Evaluation of the PTN-104 Plethysmographic Sensor for Heart Rate Measurement

“…Conventional non-invasive methods for cardiac activity measurement include electrocardiogram (ECG) and photoplethysmography (PPG). Both methods, although based on different concepts and measuring different phenomena, provide reliable results when used correctly [11], [12].…”

“…A simple plethysmographic device consists of a light source (usually red or near-infrared (NIR)) and a photodetector. The illuminated tissue is relatively transparent to NIR wavelengths and the level of absorption depends on hemoglobin, the oxygen transport protein that strongly absorbs NIR light [11], [12]. The variations in volume and photodetector response are related using the Beer-Lambert's law (1), which states that by illuminating tissue with an absorption coefficient α with a light source of intensity I0 and measuring the fraction of light received It, changes in thickness d can be assessed [14].…”

“…During the cardiac cycle, an increase in NIR light absorbance is seen during periods of high pressure (systole), while a decrease in NIR light absorbance is seen during periods of low pressure (diastole). As systolic and diastolic phases are synchronized with HR, based on that HR can be quickly indicated [11], [12]. PPG signal can be obtained by using a pulse oximeter.…”