ADDRESS

4th floor

Merz Court 

Newcastle Univeristy 

NE1 7RU, UK

CONTACT INFORMATION

Merz Reception

E-mail: merz.reception@newcastle.ac.uk

Address: 3rd floor, Merz Court,

School of Engineering,

Newcastle University, NE1 7RU, UK

Copyright © by Neuroprosthesis lab | Newcastle University

Retinal Prosthesis

Blindness – a major societal problem

According to the World Health Organization (WHO) in 2014, there are 39 million blind people worldwide. The impact on the individual is severe and makes fulfilling their hopes and dreams in love and career much more difficult. Pharmaceutical, stem cell, and gene therapy methods are all progressing, but there are two key conditions which are suitable for neuroprosthetic treatment:

 

 

1. Retinitis Pigmentosa (Prev: 1:3000) is a condition which stops light-sensing photoreceptors in the eye from functioning but leaves the communication cells to the brain intact. So if a neuroprosthetic system can stimulate remaining cells in the retina, it could restore vision.

 

 

2. Glaucoma: (Prev: 3.5%): Is a condition which eventually cuts the optic nerve, thus preventing signals from the eye reaching the brain. As such, for a neuroprosthetic system to restore sight, it would need to intervene directly in the visual brain – either the visual part of the thalamus (LGN) or the Visual Cortex.

The neuroprosthesis lab is working on solutions to both forms which can be tackled via neuroprosthetic systems. Our solutions centre on the optogenetic method – arising from the 2003 discovery that it is possible to make nerve cells light sensitive with genetic means. We hope that this can get around one of the primary challenges in with electrical approaches: By stimulating ON (positive) and OFF (negative) pathways simultaneously – you pass very little net information to the visual system. In contrast, using genetic methods together with advanced optoelectronics, it is possible to target specific sub-circuits and (hopefully) bring back a much better level of visual return.

 

Optogenetic Retinal Prosthesis.

The basic concept of any visual prosthesis is to acquire the visual scene through an imaging device, process it in a way to best communicate with the human visual system and then stimulate the remaining nervous tissue.  In the case of optogenetic retinal prosthesis – there are two primary aspects:

 

1. A gene therapy: Which would photosensitize a remaining cell layer – most probably either the bipolar cells (processing cells in the eye) or the retinal ganglion cells (communication cells projecting to the brain).

2. An optoelectronic headset: Which acquires the visual scene, performs processing to mimic the processing of the eye and then transmit optical information to the new photosensitized cell layers.

As an engineering neuroprosthetics team, we have focussed on the development of the headset, while others are engaged in clinical trials for the gene therapy aspect. Our Newcastle optogenetic retinal prosthesis headset captures the scene using standard cameras, though we have also explored integrating infrared in particular. The scene is then processed via a video processor, first to simplify the scene to be presented, and then to provide retinal processing. The videoprocessor then engages with a custom OptoNeuro stimulator chip via a microcontroller. Our OptoNeuro device has been designed to provide a custom (7x7mm) 90x90 microdisplay to provide and high-intensity stimulus on the retina. Efficacy has been proved in biological retina as per our publications below.

The basic concept of any visual prosthesis is to acquire the visual scene through an imaging device, process it in a way to best communicate with the human visual system and then stimulate the remaining nervous tissue.  In the case of optogenetic retinal prosthesis – there are two primary aspects:

 

1. A gene therapy: Which would photosensitize a remaining cell layer – most probably either the bipolar cells (processing cells in the eye) or the retinal ganglion cells (communication cells projecting to the brain).

2. An optoelectronic headset: Which acquires the visual scene, performs processing to mimic the processing of the eye and then transmit optical information to the new photosensitized cell layers.

As an engineering neuroprosthetics team, we have focussed on the development of the headset, while others are engaged in clinical trials for the gene therapy aspect. Our Newcastle optogenetic retinal prosthesis headset captures the scene using standard cameras, though we have also explored integrating infrared in particular. The scene is then processed via a video processor, first to simplify the scene to be presented, and then to provide retinal processing. The videoprocessor then engages with a custom OptoNeuro stimulator chip via a microcontroller. Our OptoNeuro device has been designed to provide a custom (7x7mm) 90x90 microdisplay to provide and high-intensity stimulus on the retina. Efficacy has been proved in biological retina as per our publications below.

Concepts in Visual prosthetics:

In the near future, it is unlikely that we will see a perfect return of all vision. However, we can consider ways to make prosthetics more function.

 

In the “song of the Machine” video project (together with the brilliant Superflux design team), we explored how super-vision such as infrared and ultraviolet could either help or simply provide new and interesting ways of viewing the world.

Completed Projects:

  1. 2008-2011 Retinal prosthetics: a novel opto-bionic approach to the restoration of functional vision EPSRC (EP/F029241/1)

  2. 2010-2014 OptoNeuro – a platform for OPTOgenetic NEURal StimulatiOn European commission (216344044)

Neuroprosthetic lab papers in this domain:

  1. Ahmed Soltan, John Barrett, Pleun Maaskant, Niall Armstrong, Walid Al Atabany, Lionel Chaudet, Mark Neil, Evelyne Sernagor, Patrick Degenaar, "A Head Mounted Device Stimulator for Optogenetic Retinal Prosthesis," Journal of Neural Engineering, vol. 15, no. 6, p. 065002, 2018.

  2. Soltan, Ahmed and Zhao, Hubin and Chaudet, Lionel and Neil, Mark and Maaskant, Pleun and Degenaar, Patrick, "An 8100 pixel optoelectronic array for optogenetic retinal prosthesis," in Biomedical Circuits and Systems Conference (BioCAS), 2014 IEEE, Louzane, 2014.

  3. Ahmed Soltan, Passetti G, Maaskant P, Degenaar P., "High-density μLED array for retinal prosthesis with a eye-tracking system.," in Biomedical Circuits and Systems Conference (BioCAS), 2016.

  4. Ahmed Soltan and McGovern, Brian and Drakakis, Emmanuel and Neil, Mark and Maaskant, Pleun and Akhter, Mahbub and Lee, Jun Su and Degenaar, Patrick, "High Density, High Radiance µLED Matrix for Optogenetic Retinal Prostheses and Planar Neural Stimulation," IEEE Transactions on Biomedical Circuits and Systems, vol. 2, no. 11, pp. 347--359, 2017.

  5. McGovern, Brian and Berlinguer Palmini, R and Grossman, Nir and Drakakis, E and Poher, Vincent and Neil, MAA and Degenaar, Patrick, "A new individually addressable micro-LED array for photogenetic neural stimulation," Biomedical Circuits and Systems, IEEE Transactions on, vol. 4, no. 6, pp. 469-476, 2010.

  6. Al-Atabany, Walid and McGovern, Brian and Mehran, Kamyar and Berlinguer-Palmini, Rolando and Degenaar, Patrick, "A processing platform for optoelectronic/optogenetic retinal prosthesis," Biomedical Engineering, IEEE Transactions on, vol. 60, no. 3, pp. 781-791, 2011.

  7. Al-Atabany, Walid I and Memon, Muhammad A and Downes, Susan M and Degenaar, Patrick, "Designing and testing scene enhancement," Biomed. Eng. Online, vol. 9, pp. 1--25, 2010.

  8. Chaudet, Lionel and Neil, Mark and Degenaar, Patrick and Mehran, Kamyar and Berlinguer-Palmini, Rolando and Corbet, Brian and Maaskant, Pleun and Rogerson, David and Lanigan, Peter and Bamberg, Ernst and others, "Development of optics with micro-LED arrays for improved opto-electronic neural stimulation," in Optogenetics: Optical Methods for Cellular Control: International Society for Optical Engineering., San Francisco, CA, USA, 2013.

  9. Grossman, Nir and Nikolic, Konstantin and Toumazou, Christofer and Degenaar, Patrick, "Modeling study of the light stimulation of a neuron cell with channelrhodopsin-2 mutants," Biomedical Engineering, IEEE Transactions on, vol. 58, no. 6, pp. 1742--1751, 2011.

  10. Degenaar, Patrick and Grossman, Nir and Memon, Muhammad Ali and Burrone, Juan and Dawson, Martin and Drakakis, Emmanuel and Neil, Mark and Nikolic, Konstantin, "Optobionic vision—a new genetically enhanced light on retinal prosthesis," Journal of neural engineering, vol. 6, no. 3, p. 035007, 2009.