Visual implant

The problem it addresses

Visual prostheses aim to restore some form of sight by electrically stimulating the nervous system in patterns. The finer and more numerous the contacts, the more detailed the pattern could in principle be. But very small electrodes must still be able to pass enough current, safely, to stimulate tissue.

What the patent describes

The patent describes a visual implant built from an array of micro-electrodes, including at least two stimulation electrodes. Each electrode has a conducting core surrounded by insulation, with a layer of metal or metal-oxide nanostructures on its front tip, where it contacts the target tissue. An integrated circuit controls the pattern of stimulation current delivered through the array.

The description explains the approach in more detail: narrow, glass-insulated metal microwires with nanostructured tips, driven by an integrated circuit of the kind used to control the pixels of a display. It discusses stimulating several electrodes at once in patterns, deriving stimulation patterns from images, optional sensing electrodes (for example, for glucose or pH), and wireless power.

Why it matters

The invention combines two ideas: electrodes fine enough to be packed densely with limited disturbance to tissue, and tips engineered to carry stimulation current efficiently. Our peer-reviewed work on jULIEs later showed, in mice, that single nanostructured glass–metal fibres could stimulate nearby neurons. Read our article on that paper.

What a patent is, and is not

A granted patent records that an invention was disclosed and examined for novelty. It is not evidence that a visual implant has been built, tested in people or shown to restore vision. The rights in this patent are assigned to The Francis Crick Institute Ltd.