Summary form only given. Biomedical application will be one of the most important applications in VLSI design field near future, and this special session informs you the hottest biomedical applications related to artificial vision systems and brain machine interface. We invite three speakers Prof. Ohta from Japan, Prof. Suaning form Australia, Prof. Wu from Taiwan, and a keynote speaker Dr. Torres-Martinez from France as leading authorities of this field to have panel discussion. Attendee will enjoy the information of the state of the art of this area all over the world and get information for difficulties and challenging to develop biomedical application systems and biomedical application itself.

Advancement of retinal neuro-prosthesis technologies has reached a point where multiple devices are now available clinically as a therapeutic treatment for degenerative disorders of the retina. Reported outcomes have typically fallen short of patient and researcher expectations, and true restoration of vision remains an elusive objective. Here, the state of the art in visual prostheses is explored from the perspective of stimulus delivery, and solutions for outstanding challenges are proposed and analyzed.

Delay elements are used in integrated circuits (ICs) to meet design specific timing requirements. Delays are often generated by increasing the input transition times. For long delays, such a signal generally results in prolonged short-circuit current either within the delay element itself or at the subsequent stage, elevating the overall power consumption of the system. In this paper, a novel CMOS semi-static threshold triggered delay element architecture is proposed, that can also be configured to work with other conventional delay elements, to minimize the short-circuit current over a wide delay range resulting in a predictable output delay and reduced power consumption. The semi-static threshold-triggered delay element is fabricated in a commercial 0.35 μm CMOS technology and comparative results show significant improvements in operating range and power consumption over other well-known delay elements.

In this paper, we investigate a passive charge recovering stimulation strategy that can potentially halve the stimulation power consumption in implantable neuro-stimulators. We propose a simple circuit implementation and an electrode-tissue interface model and use this to simulate average electrode currents and electrode resting potentials over a range of stimulation and electrode parameters. We compare said measures with same for a capacitively coupled stimulation strategy and a post-stimulation electrode shortening strategy finding that the passive charge recovering strategy is comparable to post-stimulation shortening. The simulations are confirmed with in-vitro measurements in physiological saline.

The state of the art of biological-machine systems integration (BMSI) with an emphasis on neural interfacing is reported. The goal of BMSI from a medical viewpoint is to effectively replace or facilitate activation of, or recording from, neural elements in a part of the nervous system. BMSI will be firstly examined from a generic level whereby the current technologies for noninvasive and invasive neural recording and neural stimulation will be detailed. A case study in the area of visual neuroprosthesis will be presented to elucidate the current and future issues facing BMSI. This will include a discussion on biocompatibility, design of stimulating electrodes, the implanted microelectronic neurostimulator, and parallelization of stimulus encoding and delivery.

In this paper, we discuss system architectures, design challenges and circuit implementation principles for intraocular epiretinal neuro-stimulators to be used as part of vision prostheses in partially restoring vision to the blind. Our unique hexagonal electrode placement allows focused simultaneous stimulation which allow the electrode count to scale. A new dual-channel transcutaneous inductive link is used to transfer power and data efficiently to the implant, and a new dual-voltage power rectifier provides two implant supplies without the need for a DC-DC converter. Low-power designs of current stimulators and ECAP amplifiers are also outlined in the paper.