A Low Power Time Domain ECG Interface Based on Flexible a-IGZO TFTs
conference paper
This work presents a low power ECG interface for wearable applications, based on unipolar a-IGZO TFTs manufactured on a flexible substrate. The interface consists of a cascaded diode-connected load preamplifier followed by a reset integrator, which is used to convert the voltage signal to a pulse-width modulated (PWM) representation. The output is thus provided as a binary PWM waveform, which can be conveniently sent to a reader device using wireless communication and can be further converted to a digital representation using a simple counter. The flicker noise and the offset are eliminated using an approach similar to correlated double sampling. An input chopper is exploited to alternate the connection between the inputs of the preamplifier for each sample. The output signal is then extracted by subtracting two consecutive samples after conversion to the digital domain. In this way offset and low-frequency noise, which are correlated between the two samples, are effectively cancelled.
TNO Identifier
869350
ISBN
978-1-7281-0557-4
Publisher
Institute of Electrical and Electronics Engineers Inc.
Article nr.
8791321
Source title
Proceedings - 2019 8th International Workshop on Advances in Sensors and Interfaces, IWASI 2019, 8th International Workshop on Advances in Sensors and Interfaces, IWASI 2019, 13 June 2019 through 14 June 2019
Pages
205-209
Files
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