Design and Validation of a New PPG Module to Acquire High-Quality Physiological Signals for High-Accuracy Biomedical Sensing

Kao, Yu-Hsiang; Chao, Paul C.-P.; Wey, Chin‐Long

doi:10.1109/jstqe.2018.2871604

Cited by 49 publications

(34 citation statements)

References 33 publications

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“…The artifact-free raw PPG signal (Fig. 3, bottom) is dominated by a large DC offset while the AC signal amplitude comprises only about 1-10 % of the total scope [42], [43]. Depending on the ADC's resolution, typically ≥ 16 bit, the digital representation and storage of measurements requires a lot of memory.…”

Section: A Methods For Heart Rate Monitoringmentioning

confidence: 99%

Optimal Preprocessing of Raw Signals from Reflective Mode Photoplethysmography in Wearable Devices

Wolling

Wasala

Laerhoven

2021

2021 43rd Annual International Conference of the IEEE Engineering in Medicine &Amp; Biology Society (EMBC)

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The optical measurement principle photoplethysmography has emerged in today's wearable devices as the standard to monitor the wearer's heart rate in everyday life. This cost-effective and easy-to-integrate technique has transformed from the original transmission mode pulse oximetry for clinical settings to the reflective mode of modern ambulatory, wrist-worn devices. Numerous proposed algorithms aim at the efficient heart rate measurement and accurate detection of the consecutive pulses for the derivation of secondary features from the heart rate variability. Most, however, have been evaluated either on own, closed recordings or on public datasets that often stem from clinical pulse oximeters in transmission instead of wearables' reflective mode. Signals tend furthermore to be preprocessed with filters, which are rarely documented and unintentionally fitted to the available and applied signals.We investigate the influence of preprocessing on the peak positions and present the benchmark of two cutting-edge pulse detection algorithms on actual raw measurements from reflective mode photoplethysmography. Based on 21806 pulse labels, our evaluation shows that the most suitable but still universal filter passband is located at 0.5 to 15.0 Hz since it preserves the required harmonics to shape the peak positions.

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Section: A Methods For Heart Rate Monitoringmentioning

confidence: 99%

Optimal Preprocessing of Raw Signals from Reflective Mode Photoplethysmography in Wearable Devices

Wolling

Wasala

Laerhoven

2021

2021 43rd Annual International Conference of the IEEE Engineering in Medicine &Amp; Biology Society (EMBC)

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“…In this work, we have reused the optical skin model presented in [12]. This model considers a seven layer structure and it has been proven sufficiently accurate to model primary effects of photon-skin interactions [19], [20], [21]. As shown in [12], TracePro® is used to simulate the nonpulsatile (DC) and pulsatile (AC) components of the optical signal.…”

Section: Optical Module Optimizationmentioning

confidence: 99%

Ring-Embedded Micro-Power mm-Sized Optical Sensor for Accurate Heart Beat Monitoring

Boukhayma¹,

Barison²,

Haddad³

et al. 2021

IEEE Access

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This paper presents a wearable optical health monitoring device embedding a monolithic sensor chip with newly designed pixels, and an optical module optimized for photoplethysmography (PPG). The monolithic optical sensor at the heart of this device implements an array of novel pixels designed specifically for PPG and featuring a quantum efficiency (QE) as high as 85 %. The sensor readout chain, as well as the logic circuits, implements low power design techniques leading to only 60 µA current consumption at 122 Hz operation frequency, including digital communication. Thanks to the high QE and optical module optimization, medical grade PPG recordings are enabled with less than 10 µA emitter current. The optical sensor is embedded in an ergonomic ring device together with system electronics in order to enable in-field test of beat detection accuracy on 7 subjects. The ring device detects correctly 97.87 % of the beats on a total of 72.21 hours of recording. The inter-beat interval (IBI) estimation from these recordings features a mean absolute error (MAE) as low as 8.10 ms. This performance is achieved with less than 70 µA current consumption at the level of the PPG module.INDEX TERMS CMOS image sensor, heart beat detection, low power integrated circuit, monolithic optical detector, photoplethismography sensor, wearable electronics.

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“…For the simulation the tissue modelled by assuming the standard thicknesses of different layers under the skin, such as 0.1 mm to 0.14 mm for epidermis, 0.5 mm to 3 mm for dermis, and 3 mm to 50 mm for sub-cutis. The thickness of pulsating wrist artery is assumed as 2-2.2 mm (Pribadi et al 2020;Pandey et al 2019;Kao et al 2019). Typically, the optical properties of these layers are characterized by absorption l a and scattering l s coefficients and the anisotropy factor g. The absorption coefficient characterizes the average number of absorption events per unit path length of photons travelling in the tissue.…”

Section: Oled-opd Sensor Array Designmentioning

confidence: 99%

External temperature sensor assisted a new low power photoplethysmography readout system for accurate measurement of the bio-signs

Pandey

Chao

2020

Microsyst Technol

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This study presents an external temperature sensor assisted a new low power, time-interleave, wide dynamic range, and low DC drift photoplethysmography (PPG) signal acquisition system to obtain the accurate measurement of various bio signs in real-time. The designed chip incorporates a 2-bit control programmable transimpedance amplifier (TIA), a high order filter, a 3:8 programmable gain amplifier (PGA) and 2 9 2 organic light-emitting diode (OLED) driver. Temperature sensor is used herein to compensate the adverse effect of low-skin-temperature on the PPG signal quality. The analog front-end circuit is implemented in the integrated chip with chip area of 2008 lm 9 1377 lm and fabricated via TSMC T18 process. With the standard 1.8 V, the experimental result shows that the measured current sensing range is 20 nA-100 uA. The measured dynamic range of the designed readout circuit is 80 dB. The estimated signal to noise ratio is 60 dB@1 uA, and the measured input referred noise is 60.2 pA/Hz. The total power consumption of the designed chip is 31.32 lW (readout) ? 1.62 mW (OLED driver@100% duty cycle). The non-invasive PPG sensor is applied to the wrist artery of the 40 healthy subjects for sensing the pulsation of the blood vessel. The experimental results show that for every 1°C decrease in mean ambient temperature tends to 0.06 beats/min, 0.125 mmHg and 0.063 mmHg increase in hear rate (HR), systolic (SBP) and diastolic (DBP), respectively. Similarly, for every 1°C increase in mean ambient temperature tends to 0.13 beats/min, 0.601 mmHg and 0.121 mmHg increase in HR, SBP and DBP, respectively. The measured accuracy and standard error for the HR estimation are 96%, and-0.022 ± 2.589 beats/minute, respectively. The oxygen stauration (S p O 2) measurement results shows that the mean absolute percentage error is less than 5%. The resultant errors for the SBP and DBP measurement are-0.318 ± 5.19 mmHg and-0.5 ± 1.91 mmHg, respectively.

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Design and Validation of a New PPG Module to Acquire High-Quality Physiological Signals for High-Accuracy Biomedical Sensing

Cited by 49 publications

References 33 publications

Optimal Preprocessing of Raw Signals from Reflective Mode Photoplethysmography in Wearable Devices

Optimal Preprocessing of Raw Signals from Reflective Mode Photoplethysmography in Wearable Devices

Ring-Embedded Micro-Power mm-Sized Optical Sensor for Accurate Heart Beat Monitoring

External temperature sensor assisted a new low power photoplethysmography readout system for accurate measurement of the bio-signs

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