A 108 dB DR Δ∑-∑M Front-End With 720 mV Input Range and >±300 mV Offset Removal for Multi-Parameter Biopotential Recording.

The recording of biopotential signals using techniques such as electroencephalography (EEG) and electrocardiography (ECG) poses important challenges to the design of the front-end readout circuits in terms of noise, electrode DC offset cancellation and motion artifact tolerance. In this paper, we present a 2-order hybrid-CTDT Δ∑-∑ modulator front-end architecture that tackles these challenges by taking advantage of the over-sampling and noise-shaping characteristics of a traditional Δ∑ modulator, while employing an extra ∑-stage in the feedback loop to remove electrode DC offsets and accommodate motion artifacts. To meet the stringent noise requirements of this application, a capacitively-coupled chopper-stabilized amplifier located in the forward path of the modulator loop serves simultaneously as an input stage and an active adder.

A Compact Quad-Shank CMOS Neural Probe With 5,120 Addressable Recording Sites and 384 Fully Differential Parallel Channels.

Large-scale in vivo electrophysiology requires tools that enable simultaneous recording of multiple brain regions at single-neuron level. This calls for the design of more compact neural probes that offer even larger arrays of addressable sites and high channel counts. With this aim, we present in this paper a quad-shank approach to integrate as many as 5,120 sites on a single probe.

Safety ensuring retinal prosthesis with precise charge balance and low power consumption.

Ensuring safe operation of stimulators is the most important issue in neural stimulation. Safety, in terms of stimulators' electrical performances, can be related mainly to two factors; the zero-net charge transfer to tissue and the heat generated by power dissipation at tissue. This paper presents a safety ensuring neuro-stimulator for retinal vision prostheses, featuring precise charge balancing capability and low power consumption, using a 0.

Required matching accuracy of biphasic current pulse in multi-channel current mode bipolar stimulation for safety.

In neural stimulation, a current mode stimulation is preferred to a voltage mode stimulation, as it has more control over injecting charge into tissue. A matched biphasic current pulse is often employed in current mode stimulation. For safe neural stimulation, in other words, to ensure zero-net charge transfer (charge balance) into tissue, it is required to utilise a precisely matched biphasic current pulse.

A precise charge balancing and compliance voltage monitoring stimulator front-end for 1024-electrodes retinal prosthesis.

In this paper, we present a precise charge balancing and compliance voltage monitoring stimulator front-end for 1024-electrode retinal prosthesis. Our stimulator is based on current mode stimulation. To generate a precisely matched biphasic current pulse, a dynamic current copying technique is applied at the stimulator front-end.