NeuroEngineering Laboratory, Department of Electronic and Electrical Engineering, The University of Melbourne, Melbourne, Vic. 3010, Australia.
IEEE Trans Biomed Eng. 2012 Feb;59(2):339-45. doi: 10.1109/TBME.2011.2171961. Epub 2011 Oct 17.
In order to develop retinal implants with a large number of electrodes, it is necessary to ensure that they do not cause damage to the neural tissue by the heat that the electrical circuits generate. Knowledge of the amount of power that induces thermal damage will assist in development of power budgets for implants, which has a significant effect upon the design of the prostheses circuitry. In this study, temperatures were measured at multiple locations on the retina while the retina was heated in cadaver and in vivo preparations using a variety of prosthesis implantation sites. A finite element thermal model of the cat eye was also created and validated by the cadaver and in vivo tests, allowing for a much larger spectrum of thermal influences to be evaluated without additional animal experimentation. To ensure that retinal tissue temperatures are not increased by more than 2 °C, a 5 mm × 5 mm, suprachoroidally implanted heating element must not dissipate more than 135 mW (5.4 mW/mm (2)).
为了开发具有大量电极的视网膜植入物，有必要确保它们不会因电路产生的热量而对神经组织造成损害。了解引起热损伤的功率量将有助于为植入物制定功率预算，这对假体电路的设计有重大影响。在这项研究中，使用各种假体植入部位，在尸体和体内准备过程中，在视网膜的多个部位测量了温度。还创建了猫眼的有限元热模型，并通过尸体和体内测试进行了验证，从而可以在无需进行额外的动物实验的情况下，评估更大范围的热影响。为了确保视网膜组织温度不会升高超过 2°C，必须将 5mm×5mm 的脉络膜上植入式加热元件的耗散功率限制在 135mW 以内（5.4mW/mm²）。
