2023 article

A Wireless Multimodal Physiological Monitoring ASIC for Injectable Implants

IEEE 49TH EUROPEAN SOLID STATE CIRCUITS CONFERENCE, ESSCIRC 2023, pp. 305–308.

By: L. Zhao*, R. Stephany*, Y. Han*, P. Ahmmed n, A. Bozkurt n & Y. Jia*

author keywords: injectable implant; multimodal sensing; ECG; PPG; temperature sensing; physiological monitoring
TL;DR: This paper presents a wireless multimodal physiological monitoring ASIC fabricated in a CMOS 180 nm process that is sized to be within the form factor of an injectable microchip implant and can measure electrocardiography, photoplethysmography, and body temperature. (via Semantic Scholar)
UN Sustainable Development Goal Categories
7. Affordable and Clean Energy (OpenAlex)
Source: Web Of Science
Added: November 13, 2023

This paper presents a wireless multimodal physiological monitoring ASIC fabricated in a CMOS 180 nm process. The application-specific integrated circuit (ASIC) is sized to be within the form factor of an injectable microchip implant and can measure electrocardiography (ECG), photoplethysmography (PPG), and body temperature. The low-power circuit design enables the ASIC to wirelessly receive the required power, 155.3 μW on average, via an inductive link. The ECG analog frontend (AFE) has input-referred noise (IRN) of 3.1 μVrms within 0. 3-1kHz. To measure PPG, the LED driver employs a switched-capacitor-based architecture as an energy-efficient and safe method to deliver current pulses in milliampere order to an LED. An integrator-based AFE amplifies the photodetector (PD) current with 47 pArms IRN within 0.1-10 Hz. Recorded physiological signals are digitized by a 10-bit successive approximation register (SAR) analog-to-digital converter (ADC) with an 8.79-bit effective number of bits (ENOB), followed by a backscatter-based data telemetry, which transmits data via intermediate-frequency (IF)-assisted load shift keying (LSK) modulation. The overall ASIC performance has been evaluated in vivo on anesthetized rats.