Recent advances in charge balancing for functional electrical stimulation

Sooksood, Kriangkrai; Ortmanns, Maurits

doi:10.1109/iembs.2009.5333181

Cited by 17 publications

(12 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Numerous charge-balancing techniques have been proposed in the past, most of which are only applicable to current stimulation [11]. The approach taken here is to monitor and integrate the stimulation current via a floating current sense resistor, programmable gain amplifier, and opamp in an integrator configuration (see Fig.…”

Section: Stimulator Architecturementioning

confidence: 99%

Towards a Switched-Capacitor based Stimulator for efficient deep-brain stimulation

Vidal

Ghovanloo

2010

2010 Annual International Conference of the IEEE Engineering in Medicine and Biology

View full text Add to dashboard Cite

We have developed a novel 4-channel prototype stimulation circuit for implantable neurological stimulators (INS). This Switched-Capacitor based Stimulator (SCS) aims to utilize charge storage and charge injection techniques to take advantage of both the efficiency of conventional voltage-controlled stimulators (VCS) and the safety and controllability of current-controlled stimulators (CCS). The discrete SCS prototype offers fine control over stimulation parameters such as voltage, current, pulse width, frequency, and active electrode channel via a LabVIEW graphical user interface (GUI) when connected to a PC through USB. Furthermore, the prototype utilizes a floating current sensor to provide charge-balanced biphasic stimulation and ensure safety. The stimulator was analyzed using an electrode-electrolyte interface (EEI) model as well as with a pair of pacing electrodes in saline. The primary motivation of this research is to test the feasibility and functionality of a safe, effective, and power-efficient switched-capacitor based stimulator for use in Deep Brain Stimulation.

show abstract

Section: Stimulator Architecturementioning

confidence: 99%

Towards a Switched-Capacitor based Stimulator for efficient deep-brain stimulation

Vidal

Ghovanloo

2010

2010 Annual International Conference of the IEEE Engineering in Medicine and Biology

View full text Add to dashboard Cite

show abstract

“…The passive ones rely on a large blocking capacitor (not feasible for fabrication on an integrated circuit) or eletrode shortening [9]. The last is not suitable for multielectrode applications in which one shortened electrode will harm nearby electrodes stimuly.…”

Section: Introductionmentioning

confidence: 99%

Direct Feedback Topology for Reducing Residual Voltage in Functional Electrical Stimulation

Teixeira

Rodrigues²,

Prior³

2015

Proceedings of the 28th Symposium on Integrated Circuits and Systems Design

View full text Add to dashboard Cite

Implantable functional electric stimulation (FES) systems are currently being investigated as treatment for some types of neural dysfunctions. For this purpose, several neural stimulator systems on a chip (SOCs) have been proposed for: deep brain stimulation (DBS), cochlear prosthesis, visual prosthesis (VP), and artificial limbs control. Two major and related issues in FES are the charge balancing and Faradaic currents. When stimulation currents have DC components, or if residual voltage persists accross electrodes, the accumulated electronic charge is converted into ionic species, thus feeding irreversible Faradaic reactions that damage electrodes and necrose tissues. This article introduces circuit solutions for balancing functional electrical stimulation whilst reducing residual voltages at electrodes. The circuit consists of four blocks: an ultra-low-power charge-redistribution digital-to-analog converter (CR-DAC), a feedback mechanism, a high-voltage H-bridge and a digital controller. To prove the effectiveness of the proposed topology a circuit is being designed in CMOS UMC130nm technology, and simulation results suggest that proposed technique allows to keep electrode voltage under safe limits, smaller than 28mV .

show abstract

“…Current-controlled stimulation features direct control over the electrode current [15] but do not provide any control over the electrode voltage, so that high electrode voltages can occur entailing unwanted electrochemistry, tissue damage, or electrode degradation. Mostly biphasic current pulses with opposite polarity in each phase are used, along with charge-balancing techniques to assure zero net charge transfer [16]. Charge balancing can be achieved using large blocking capacitors (several hundred nF) at the output of the stimulation circuit to block DC currents [17, 18].…”

Section: Introductionmentioning

confidence: 99%

Stimulation and Artifact-Suppression Techniques for In Vitro High-Density Microelectrode Array Systems

Shadmani

Viswam

Chen

et al. 2019

IEEE Trans. Biomed. Eng.

View full text Add to dashboard Cite

We present novel voltage stimulation buffers with controlled output current, along with recording circuits featuring adjustable high-pass cut-off filtering to perform efficient stimulation while actively suppressing stimulation artifacts in high-density microelectrode arrays. Owing to the dense packing and close proximity of the electrodes in such systems, a stimulation through one electrode can cause large electrical artifacts on neighboring electrodes that easily saturate the corresponding recording amplifiers. To suppress such artifacts, the high-pass corner frequencies of all available 2048 recording channels can be raised from several Hz to several kHz by applying a “soft-reset” or pole-shifting technique. With the implemented artifact suppression technique, the saturation time of the recording circuits, connected to electrodes in immediate vicinity to the stimulation site, could be reduced to less than 150 μs. For the stimulation buffer, we developed a circuit, which can operate in two modes: either control of only the stimulation voltage, or control of current and voltage during stimulation. The voltage-only controlled mode employs a local common-mode feedback operational transconductance amplifier with a near rail-to-rail input/output range, suitable for driving high capacitive loads. The current/voltage controlled mode is based on a positive current conveyor generating adjustable output currents, while its upper and lower output voltages are limited by two feedback loops. The current/voltage controlled circuit can generate stimulation pulses up to 30 μA with less than ±0.1% linearity error in the low-current mode, and up to 300 μA with less than ±0.2% linearity error in the high-current mode.

show abstract

Recent advances in charge balancing for functional electrical stimulation

Cited by 17 publications

References 9 publications

Towards a Switched-Capacitor based Stimulator for efficient deep-brain stimulation

Towards a Switched-Capacitor based Stimulator for efficient deep-brain stimulation

Direct Feedback Topology for Reducing Residual Voltage in Functional Electrical Stimulation

Stimulation and Artifact-Suppression Techniques for In Vitro High-Density Microelectrode Array Systems

Contact Info

Product

Resources

About