Low-Power Photoplethysmogram Acquisition Integrated Circuit with Robust Light Interference Compensation

Abstract

To overcome light interference, including a large DC offset and ambient light variation, a robust photoplethysmogram (PPG) readout chip is fabricated using a 0.13-μm complementary metal–oxide–semiconductor (CMOS) process. Against the large DC offset, a saturation detection and current feedback circuit is proposed to compensate for an offset current of up to 30 μA. For robustness against optical path variation, an automatic emitted light compensation method is adopted. To prevent ambient light interference, an alternating sampling and charge redistribution technique is also proposed. In the proposed technique, no additional power is consumed, and only three differential switches and one capacitor are required. The PPG readout channel consumes 26.4 μW and has an input referred current noise of 260 pArms.

Film mood induction and emotion classification using physiological signals for health and wellness promotion in older adults living alone

“…A single‐supply, rail‐to‐rail input/output, precision operational amplifier implements a voltage‐controlled linear current source. On the other hand, PPG signals are measured through an optical plethysmogram technique, using a light‐emitting diode (LED), LED driver circuitry, and photo‐detector sensors (Kim, Kim, & Ko, ).…”

“…A single-supply, rail-to-rail input/output, precision operational amplifier implements a voltage-controlled linear current source. On the other hand, PPG signals are measured through an optical plethysmogram technique, using a light-emitting diode (LED), LED driver circuitry, and photo-detector sensors (Kim, Kim, & Ko, 2015). Although PPG acquisition and signal conditioning require several processing and complex circuits, there are commercial fully integrated analogue front ends and optical sensors suitable for PPG signals that simplify the hardware design.…”

Estimation of Mental Distress from Photoplethysmography

“…In a PPG acquisition and signal conditioning circuit there are several key elements: light emitting diode (LED), LED driver circuitry, photo-detector (PD), and PD signal conditioning circuitry [22]. Although it is possible to address the development of these elements from scratch, nowadays there are commercial fully-integrated analog front-ends and optical sensors suitable for PPG signals.…”

Reconfigurable Multiparameter Biosignal Acquisition SoC for Low Power Wearable Platform

“…Figure 7 shows an example configuration for PPG measurement [13]. The light-emitting diode (LED) controller controls the amount of light emitted from the LED.…”

“…For example, an electropotential (EP) mode is used in applications including electrocardiogram (ECG), electromyogram (EMG), and electroencephalogram (EEG) [3,4,5]; impedance (IMP) mode is used for applications including body fat based on body impedance analysis [6,7], respiration rate [8,9], and galvanic skin response [10]; electrochemical (EC) mode is used in applications including blood glucose monitoring [11]; and photoelectric (PE) mode is used in applications including photoplethysmography (PPG) [12,13] and blood oxygen saturation [14,15]. Moreover, recently, as the requirements on integrated multifunctional biosignal acquisition systems are increasing, some research on multiparameter biosignal acquisition in a single system on a chip (SoC) have been reported [16,17,18].…”