Implantable Neuromorphic Vision Chips (Coursework Sample)

Implantable Neuromorphic Vision Chips
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Implantable Neuromorphic Vision Chips
Implantable electronics are used in contemporary times to improve on cardiac, cochlear and retinal prosthesis systems. Retinal prosthesis is replaces retinal function through the implants of analogue circuits which are integrated circuits. Implantable Neuromorphic Vision Chips perform four cell functions: photoreceptor, horizontal, bipolar and ganglion cells.
Horizontal cells simulation network with the other cells to provide noise immunity and high dynamic range of retinal vertebrae. They also form layers that transverse primary signals that enter the eye. The signal then enters the photoreceptor cells where it is transmitted to the bipolar cells. Bipolar cells are based in pairs and are situated beneath the retina. The latter provides a boundary between light and dark. The ganglion cells are in two groups; on-center and off-center. Bipolar terminals transmit synapses through excitatory synapses to the ganglion cells. Stimulus is generated from the ganglion cells to the optic nerve of the visual cortex (Chiang & Wu, 2004).
Iiso and Ismt currents are produced by photoreceptor and horizontal cells respectively to the bipolar cells. Bipolar cells operate with two positive current edges. The current is then converted to analogue voltage. The bipolar cells regulate the voltage of the extracted current to avoid ambiguity in the presence of noise or any other disturbances. The out put signal from the bipolar cells then enters the ganglion which generates the optical nerve impedance. Transistors exist in the vision chips to produce the correct current that is needed by the patient. Moreover, the biphasic pulses in the ganglion cells prevent accumulation of ion-charge in the tissues. The pulse duration is 300 microseconds and its frequency is 20 hz in the implantable Neuromorphic vision chips (Chiang & Wu, 2004).
Thus from the above, the retinal cells function has been improved through simulation. The function of the retina is enhanced through simulation by the Neuromorphic vision chips. The quality of the article is relevant as it explains how a Neuromorphic vision chip enhances retinal vision. The article describes in detail the cell functions of photoreceptor, horizontal, bipolar and ganglion cells. Further, it elaborates on how the implants improve the cell functions through simulation. The impulses flow from one cell to another is described in the article. The diagram enables the reader to track the signals from the time they enter the retina to the time that they reach the transistors to be discharged to the visual cortex.
However, the article is biased towards describing the signal interface of the ganglion cells than that of the other cells. It gives spatial information on what happens to the current or signal in the photoreceptors and the ganglion cells. There is also less information of the current in the biphasic stage. Despite this limitation of t...