High Resolution Implantable Microsystem and Probe Design for Retinal Prosthesis
نویسندگان
چکیده
By a retinal prosthesis, the researchers have been able to stimulate a limited number of neurons (around 100) by biphasic current stimulus to reproduce an image spatially by multiplexing technique. For functional restoration of sight (visual acuity 20/80), we are to stimulate at least 2500 neurons/mm². We are far behind that target. The time required by biphasic current stimulus, the sequential stimulation by multiplexing technique, and the conventional probes used for stimulation limits our ability to stimulate large number of neurons and maintains the persistence of vision. To address this problem, we have designed high resolution donut probes and used them in designing neural implant chip (NIC) applying parallel multiplexing technique, which helped us stimulate large number of neurons. This paper presents the design of a donut probe and an implantable CMOS-based 5x5 array NIC to demonstrate that idea. This 5x5 array NIC is scalable to any larger array. It uses external clock, which makes it suitable for any data rate. The programmable biphasic width controller (BWC) used in this design is capable of generating various kinds of stimulus for stimulation. NIC doesn't need address to route the pixels, which reduces the data transmission overhead. 0.5 microm CMOS technology is used to fabricate NIC with donut probes. Test results verify our technique of increasing the resolution.
منابع مشابه
A Wireless and Batteryless Microsystem with Implantable Grid Electrode/3-Dimensional Probe Array for ECoG and Extracellular Neural Recording in Rats
This paper presents the design and implementation of an integrated wireless microsystem platform that provides the possibility to support versatile implantable neural sensing devices in free laboratory rats. Inductive coupled coils with low dropout regulator design allows true long-term recording without limitation of battery capacity. A 16-channel analog front end chip located on the headstage...
متن کاملFlexible Electrode Array for Retinal Stimulation
In this Work, ITO/PET (Indium Tin Oxide / Polyethylene Terephthalate) electrode structure which provides biocompatibility, mechanical stability and flexibility is fabricated. Flexible ITO/PET implantable electrode array for a retina has been developed. The electrode array is fabricated on a thin PET/ITO substrate and is encapsulated using, SU-8, an insulating material. PET substrate and SU-8 po...
متن کاملStudy of Power Supply System for Fully Implantable Retinal Prosthesis Chip
Recently, with the progress of an aging society, the number of people who have suffered from retinal diseases such as retinitis pigmentosa (RP) and agerelated macular degeneration (AMD) has been remarkably increasing. However, the proper medical treatments for such diseases have not been established yet. Due to strong demands on alternative medical treatments to restore visual sensation for bli...
متن کاملStimulator Design of Retinal Prosthesis
This study focuses on the design of electrical stimulator for retinal prosthesis. The stimulator must be designed such that the occurrence of electrolysis or any irreversible process in the electrodes and flexible lead is prevented in order to achieve safe stimulation over long periods using the large number of electrodes. Some types of biphasic current pulse circuits, charge balance circuits, ...
متن کامل