A 680 nA ECG Acquisition IC for Leadless Pacemaker Applications

Abstract

Abstract-A sub-ECG acquisition IC is presented for a single-chamber leadless pacemaker applications. It integrates a low-power, wide dynamic-range ECG readout front end together with an analog QRS-complex extractor. To save ASIC power, a current-multiplexed channel buffer is introduced to drive a 7 b-to-10 b self-synchronized SAR ADC which utilizes 4 fF/unit capacitors. The ASIC consumes only 680nA and achieves CMRR 90 dB, PSRR 80 dB, an input-referred noise of 4.9 in a 130 Hz bandwidth, and has rail-to-rail DC offset rejection. Low-power heartbeat detections are evaluated with the help of the ASIC acquiring nearly 20,000 beats across 10 different records from the MIT-BIH arrhythmia database. In the presence of muscle noise, both the average Sensitivity (Se) and Positive Predictivity (PP) show more than 90% when the input SNR 6 dB.

Silicon-Integrated High-Density Electrocortical Interfaces

“…For higher density, in some designs, a SAR ADC is shared by about 8-16 AFEs using a time multiplexer [54]. In doing so, power-efficient multiplexers [71] and time-interleaving sample-and-hold circuits in SAR ADCs have been demonstrated. Alternatively, a dedicated ADC per AFE channel has been also pursued due to its ease of integration with a larger number of channels [44], [66].…”

Feasibility of Successive Approximation Register ADC in Ultra Low Power Biomedical Applications

“…An ASIC for single chamber leadless pacemaker at ultra-low power (sub µW) consumption centered at high quality ECG signal acquisition and classification has been proposed to readout and extract the information from the ECG signal using QRS complex extractor in [21]. In order to reduce the consumption of power, feature extraction is performed in analog domain followed by digitization where an ADC converts both time domain ECG signal (ECGout) and feature extracted signal (FEout) before feeding the signals to DSP.…”

A 0.5 μA/Channel front-end for implantable and external ambulatory ECG recorders

“…Conventional bio-potential measurement systems use an analog to digital converter to convert the amplified input signal into a digital format. High-gain amplifiers, various filters and high-resolution ADCs are among the usual building blocks of conventional bio-potential systems and consume large area and high power, which both are critical in wearable and implantable devices [4]- [11], [18]. The large amount of data generated by the ADC is then analyzed by a processor, stored and finally the modulated signal is transmitted for further processing.…”