scholarly journals Acquisition of Neural Action Potentials Using Rapid Multiplexing Directly at the Electrodes

Micromachines ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 477 ◽  
Author(s):  
Mohit Sharma ◽  
Avery Gardner ◽  
Hunter Strathman ◽  
David Warren ◽  
Jason Silver ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Neural Recording ◽  
Frequency Noise ◽  
Electrode Arrays ◽  
Analog To Digital ◽  
Engineering Research ◽  
Cmos Integrated Circuit ◽  
In Vivo Experiments ◽  
High Impedance

Neural recording systems that interface with implanted microelectrodes are used extensively in experimental neuroscience and neural engineering research. Interface electronics that are needed to amplify, filter, and digitize signals from multichannel electrode arrays are a critical bottleneck to scaling such systems. This paper presents the design and testing of an electronic architecture for intracortical neural recording that drastically reduces the size per channel by rapidly multiplexing many electrodes to a single circuit. The architecture utilizes mixed-signal feedback to cancel electrode offsets, windowed integration sampling to reduce aliased high-frequency noise, and a successive approximation analog-to-digital converter with small capacitance and asynchronous control. Results are presented from a 180 nm CMOS integrated circuit prototype verified using in vivo experiments with a tungsten microwire array implanted in rodent cortex. The integrated circuit prototype achieves <0.004 mm2 area per channel, 7 µW power dissipation per channel, 5.6 µVrms input referred noise, 50 dB common mode rejection ratio, and generates 9-bit samples at 30 kHz per channel by multiplexing at 600 kHz. General considerations are discussed for rapid time domain multiplexing of high-impedance microelectrodes. Overall, this work describes a promising path forward for scaling neural recording systems to numbers of electrodes that are orders of magnitude larger.

scholarly journals Visceral pressure stimulator for exploring hollow organ pain: a pilot study

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Michael DeLong ◽  
Mauricio Gil-Silva ◽  
Veronica Minsu Hong ◽  
Olivia Babyok ◽  
Benedict J. Kolber
Keyword(s):  
Visceral Pain ◽  
Bladder Pressure ◽  
Abdominal Muscles ◽  
Analog To Digital ◽  
In Vivo Experiments ◽  
Digital Pressure ◽  
Hollow Organ ◽  
Specialized Hardware ◽  
And Control

Abstract Background The regulation and control of pressure stimuli is useful for many studies of pain and nociception especially those in the visceral pain field. In many in vivo experiments, distinct air and liquid stimuli at varying pressures are delivered to hollow organs such as the bladder, vagina, and colon. These stimuli are coupled with behavioral, molecular, or physiological read-outs of the response to the stimulus. Care must be taken to deliver precise timed stimuli during experimentation. For example, stimuli signals can be used online to precisely time-lock the stimulus with a physiological output. Such precision requires the development of specialized hardware to control the stimulus (e.g., air) while providing a precise read-out of pressure and stimulus signal markers. Methods In this study, we designed a timed pressure regulator [termed visceral pressure stimulator (VPS)] to control air flow, measure pressure (in mmHg), and send stimuli markers to online software. The device was built using a simple circuit and primarily off-the-shelf parts. A separate custom inline analog-to-digital pressure converter was used to validate the real pressure output of the VPS. Results Using commercial physiological software (Spike2, CED), we were able to measure mouse bladder pressure continuously during delivery of unique air stimulus trials in a mouse while simultaneously recording an electromyogram (EMG) of the overlying abdominal muscles. Conclusions This device will be useful for those who need to (1) deliver distinct pressure stimuli while (2) measuring the pressure in real-time and (3) monitoring stimulus on–off using physiological software.

scholarly journals Spontaneous and Perturbational Complexity in Cortical Cultures

2021 ◽  
Vol 11 (11) ◽  
pp. 1453
Author(s):  
Ilaria Colombi ◽  
Thierry Nieus ◽  
Marcello Massimini ◽  
Michela Chiappalone
Keyword(s):  
Cortical Neurons ◽  
Low Frequency ◽  
Initial Response ◽  
Moderate Increase ◽  
Electrode Arrays ◽  
In Vivo Experiments ◽  
Cortical Cultures ◽  
Cortical Slices

Dissociated cortical neurons in vitro display spontaneously synchronized, low-frequency firing patterns, which can resemble the slow wave oscillations characterizing sleep in vivo. Experiments in humans, rodents, and cortical slices have shown that awakening or the administration of activating neuromodulators decrease slow waves, while increasing the spatio-temporal complexity of responses to perturbations. In this study, we attempted to replicate those findings using in vitro cortical cultures coupled with micro-electrode arrays and chemically treated with carbachol (CCh), to modulate sleep-like activity and suppress slow oscillations. We adapted metrics such as neural complexity (NC) and the perturbational complexity index (PCI), typically employed in animal and human brain studies, to quantify complexity in simplified, unstructured networks, both during resting state and in response to electrical stimulation. After CCh administration, we found a decrease in the amplitude of the initial response and a marked enhancement of the complexity during spontaneous activity. Crucially, unlike in cortical slices and intact brains, PCI in cortical cultures displayed only a moderate increase. This dissociation suggests that PCI, a measure of the complexity of causal interactions, requires more than activating neuromodulation and that additional factors, such as an appropriate circuit architecture, may be necessary. Exploring more structured in vitro networks, characterized by the presence of strong lateral connections, recurrent excitation, and feedback loops, may thus help to identify the features that are more relevant to support causal complexity.

In vivo measurements with a 64-channel extracellular neural recording integrated circuit

2014 ◽  
Author(s):  
Manuel Delgado-Restituto ◽  
Alberto Rodriguez-Perez ◽  
Angela A. Darie ◽  
Angel Rodriguez-Vazquez ◽  
Cristina Soto-Sanchez ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Neural Recording ◽  
In Vivo Measurements

scholarly journals Fabrication of Subretinal 3D Microelectrodes with Hexagonal Arrangement

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 467 ◽  
Author(s):  
Hee Won Seo ◽  
Namju Kim ◽  
Sohee Kim
Keyword(s):  
Integrated Circuit ◽  
Microelectrode Array ◽  
3D Structure ◽  
Three Dimensional ◽  
Active Electrode ◽  
Prosthetic Devices ◽  
In Vivo Experiments ◽  
Hexagonal Arrangement

This study presents the fabrication of three-dimensional (3D) microelectrodes for subretinal stimulation, to accommodate adjacent return electrodes surrounding a stimulating electrode. For retinal prosthetic devices, the arrangement of return electrodes, the electrode size and spacing should be considered together, to reduce the undesired dissipation of electric currents. Here, we applied the hexagonal arrangement to the microelectrode array for the localized activation of retinal cells and better visual acuity. To provide stimuli more efficiently to non-spiking neurons, a 3D structure was created through a customized pressing process, utilizing the elastic property of the materials used in the fabrication processes. The diameter and pitch of the Pt-coated electrodes were 150 μm and 350 μm, respectively, and the height of the protruded electrodes was around 20 μm. The array consisted of 98 hexagonally arranged electrodes, supported by a flexible and transparent polydimethylsiloxane (PDMS) base, with a thickness of 140 μm. Also, the array was coated with 2 μm-thick parylene-C, except the active electrode sites, for more focused stimulation. Finally, the electrochemical properties of the fabricated microelectrodes were characterized, resulting in the mean impedance of 384.87 kΩ at 1 kHz and the charge storage capacity (CSC) of 2.83 mC·cm−2. The fabricated microelectrodes are to be combined with an integrated circuit (IC) for additional in vitro and in vivo experiments.

Printed Stretchable Liquid Metal Electrode Arrays for In Vivo Neural Recording

Small ◽  
2021 ◽  
Vol 17 (14) ◽  
pp. 2006612
Author(s):  
Ruihua Dong ◽  
Lulu Wang ◽  
Chen Hang ◽  
Zhen Chen ◽  
Xiaoyan Liu ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Metal Electrode ◽  
Neural Recording ◽  
Electrode Arrays ◽  
Liquid Metal Electrode

scholarly journals Commercialisation of CMOS Integrated Circuit Technology in Multi-Electrode Arrays for Neuroscience and Cell-Based Biosensors

Sensors ◽  
2011 ◽  
Vol 11 (5) ◽  
pp. 4943-4971 ◽  
Author(s):  
Anthony H. D. Graham ◽  
Jon Robbins ◽  
Chris R. Bowen ◽  
John Taylor
Keyword(s):  
Integrated Circuit ◽  
Electrode Arrays ◽  
Cmos Integrated Circuit ◽  
Circuit Technology

scholarly journals An Open-Source Wireless Electrophysiological Complex for In Vivo Recording Neuronal Activity in the Rodent’s Brain

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7189
Author(s):  
Alexander Erofeev ◽  
Dmitriy Kazakov ◽  
Nikita Makarevich ◽  
Anastasia Bolshakova ◽  
Evgenii Gerasimov ◽  
...  
Keyword(s):  
Open Source ◽  
Neuronal Activity ◽  
Ex Vivo ◽  
Electrode Arrays ◽  
Charging Station ◽  
In Vivo Experiments ◽  
The Brain ◽  
Schematic Diagrams

Multi-electrode arrays (MEAs) are a widely used tool for recording neuronal activity both in vitro/ex vivo and in vivo experiments. In the last decade, researchers have increasingly used MEAs on rodents in vivo. To increase the availability and usability of MEAs, we have created an open-source wireless electrophysiological complex. The complex is scalable, recording the activity of neurons in the brain of rodents during their behavior. Schematic diagrams and a list of necessary components for the fabrication of a wireless electrophysiological complex, consisting of a base charging station and wireless wearable modules, are presented.

scholarly journals The Argo: A 65,536 channel recording system for high density neural recording in vivo

2020 ◽  
Author(s):  
Kunal Sahasrabuddhe ◽  
Aamir A. Khan ◽  
Aditya P. Singh ◽  
Tyler M. Stern ◽  
Yeena Ng ◽  
...  
Keyword(s):  
Field Potential ◽  
Neural Recording ◽  
Simultaneous Recording ◽  
Recording System ◽  
Electrode Arrays ◽  
High Data ◽  
System A ◽  
Voltage Amplifier ◽  
Neural Recording System

AbstractHere we demonstrate the Argo System, a massively parallel neural recording system based on platinum-iridium microwire electrode arrays bonded to a CMOS voltage amplifier array. The Argo system is the highest channel count in vivo neural recording system built to date, supporting simultaneous recording from 65,536 channels, sampled at over 32 kHz and 12-bit resolution. This system is designed for cortical recordings, compatible with both penetrating and surface microelectrodes. We have validated this system by recording spiking activity from 791 neurons in rats and cortical surface Local Field Potential (LFP) activity from over 30,000 channels in sheep. While currently adapted for head-fixed recording, the microwire-CMOS architecture is well suited for clinical translation. Thus, this demonstration helps pave the way for a future high data rate intracortical implant.

Investigation of High Frequency Failures on a 0.35μm CMOS IC

1999 ◽  
Author(s):  
Alan Kennen ◽  
John F. Guravage ◽  
Lauren Foster ◽  
John Kornblum
Keyword(s):  
Failure Analysis ◽  
Failure Mechanism ◽  
Integrated Circuit ◽  
Metal Layer ◽  
Ion Beam ◽  
Stress Test ◽  
Design For Test ◽  
Interface Failure ◽  
Serial Interface ◽  
High Impedance

Abstract Rapidly changing technology highlights the necessity of developing new failure analysis methodologies. This paper will discuss the combination of two techniques, Design for Test (DFT) and Focused Ion Beam (FIB) analysis, as a means for successfully isolating and identifying a series of high impedance failure sites in a 0.35 μm CMOS design. Although DFT was designed for production testing, the failure mechanism discussed in this paper may not have been isolated without this technique. The device of interest is a mixed signal integrated circuit that provides a digital up-convert function and quadrature modulation. The majority of the circuit functions are digital and as such the majority of the die area is digital. For this analysis, Built In Self Test (BIST) circuitry, an evaluation board for bench testing and FIB techniques were used to successfully identify an unusual failure mechanism. Samples were subjected to Highly Accelerated Stress Test (HAST) as part of the device qualification effort. Post-HAST electrical testing at 200MHz indicated that two units were non-functional. Several different functional blocks on the chip failed electrical testing. One part of the circuitry that failed was the serial interface. The failure analysis team decided to look at the serial interface failure mode first because of the simplicity of the test. After thorough analysis the FA team discovered increasing the data setup time at the serial port input allowed the device to work properly. SEM and FIB techniques were performed which identified a high impedance connection between a metal layer and the underlying via layer. The circuit was modified using a FIB edit, after which all vectors were read back correctly, without the additional set-up time.

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