A CMOS Chip With Active Pixel Array and Specific Test Features for Subretinal Implantation

Rothermel, Albrecht; Liu, Liu; Aryan, Naser Pour; Fischer, Michael; Wuenschmann, Juergen; Kibbel, Steffen; Harscher, Alex

doi:10.1109/jssc.2008.2007436

Cited by 103 publications

(54 citation statements)

References 16 publications

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“…It includes an array of 40 × 40 pixels, analog and digital control circuitry, and peripheral devices for interconnection. (10) Each pixel cell has dimensions of 70 × 70 μm and includes a photodiode, an amplifier, biphasic current drivers, and a circular stimulation electrode (diameter 30 µm). The electrode material is reactively sputtered Iridium Oxide (SIROF), which is a highly recommended material for stimulation electrodes.…”

Section: Electrical Functionality Of the Cmos Chipmentioning

confidence: 99%

Functionality and Performance of the Subretinal Implant Chip Alpha AMS

Daschner¹,

Rothermel²,

Rudorf³

et al. 2018

Sensors and Materials

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Electronic retinal implants have been developed and are marketed as a therapeutic option for blind people suffering from degenerative retinal diseases such as retinitis pigmentosa. The functionality of subretinal implants depends heavily on the performance of the electronic interface to the retina. For the RETINA IMPLANT Alpha AMS device, this interface consists of a subretinally implanted chip that samples the retinal image, like a camera chip, and stimulates the adjacent retina simultaneously at the corresponding locations. The technical functionality of the RETINA IMPLANT Alpha AMS is described and compared with the outcome of two clinical trials over an observation period of one year. The discrimination of different grey levels observed in these clinical trials confirms that the sensitivity of the implanted CMOS chip can be varied over the range of relevant light intensities. We show that accelerated aging lifetime measurements of implant components in a laboratory environment match implant lifetimes observed during clinical trials for the predecessor device, the RETINA IMPLANT Alpha IMS. By using the same model for the current technically advanced device, the RETINA IMPLANT Alpha AMS, the predicted clinical lifetime of the implant is about 5 years.

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Section: Electrical Functionality Of the Cmos Chipmentioning

confidence: 99%

Functionality and Performance of the Subretinal Implant Chip Alpha AMS

Daschner¹,

Rothermel²,

Rudorf³

et al. 2018

Sensors and Materials

Self Cite

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“…Therefore, power is supplied in the form of AC voltage instead of DC voltage through non-hermetically sealed parts. Figure 13 shows an example of AC power delivery [14]. In this case, the AC power is delivered in a flexible lead from the main unit to a stimulator CMOS chip as shown in Fig.…”

Section: Ac Power Deliverymentioning

confidence: 99%

Stimulator Design of Retinal Prosthesis

Ohta

Noda

Shodo

et al. 2017

IEICE Trans. Electron.

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SUMMARY 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, and AC power delivery circuits were developed to address this issue. Electronic circuitry must be introduced in the stimulator to achieve the large number of electrodes required to obtain high quality of vision. The concept of a smart electrode, in which a microchip is embedded inside an electrode, is presented for future retinal prostheses with over 1000 electrodes.

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“…Most of them fall into the area of electrical stimulation, one of the fastest growing areas of medicine, improving the lives of hundreds of thousands of patients with various disorders [23]. Visual prostheses are perhaps the most striking example with clear space constraints for which the current protection methods are not suitable [29].…”

Section: Other Applications In Implanted Devicesmentioning

confidence: 99%

Silicone rubber encapsulation for an endoscopically implantable gastrostimulator

Lonys

Vanhoestenberghe

Julemont

et al. 2015

Med Biol Eng Comput

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Gastrointestinal stimulator implants have recently shown positive results in treating obesity. However, the implantation currently requires an invasive surgical procedure. Endoscopy could be used to place the gastric stimulator in the stomach, hence avoiding the riskier surgery. The implant then needs to go through the oesophagus and be located inside the stomach, which imposes new design constraints, such as miniaturization and protecting the electronic circuit against the highly acidic environment of the stomach. We propose to protect the implant by encapsulation with silicone rubber. This paper lists the advantages of this method compared to the more usual approach of a hermetic enclosure and then presents a method to evaluate the underwater adhesive stability of six adhesive/substrate couples, using repeated lap-shear tests and an elevated temperature to accelerate the ageing process. The results for different adhesive/substrate couples tested, presented on probability plots, show that FR4 and alumina substrates with MED4-4220 silicone rubber are suitable for a first implantable prototype. We then compare these with the predicted lifetimes of bonds between historical standard silicone rubber DC3140 and different substrates and describe the encapsulation of our gastrostimulator.

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A CMOS Chip With Active Pixel Array and Specific Test Features for Subretinal Implantation

Cited by 103 publications

References 16 publications

Functionality and Performance of the Subretinal Implant Chip Alpha AMS

Functionality and Performance of the Subretinal Implant Chip Alpha AMS

Stimulator Design of Retinal Prosthesis

Silicone rubber encapsulation for an endoscopically implantable gastrostimulator

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