Abdo Ammar, Jayasinha Vianney, Spuhler Philipp S, Unlu M, Sahin Mesut
Department of Biomedical Engineering, New Jersey Institute of Technology, NJ, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:626-9. doi: 10.1109/IEMBS.2009.5334073.
Chronic tissue response to microelectrode implants stands in the way as a major challenge to development of many neural prosthetic applications. The long term tissue response is mostly due to the movement of interconnects and the resulting mechanical stress between the electrode and the surrounding neural tissue. Remotely activated floating micro-stimulators are one possible method of eliminating the interconnects. As a method of energy transfer to the micro-stimulator, we proposed to use a laser beam at near infrared (NIR) wavelengths. FLAMES of various sizes were fabricated with integrated silicon PIN photodiodes. Sizes varied from 120 (Width) x 300 (Length) x 100 (Height) microm to 200 x 500 x 100microm. Devices were bench tested using 850nm excitation from a Ti:Sapphire laser. To test this method, the voltage field of the FLAMES was experimentally tested in saline solution pulsed with a NIR laser beam. The voltage generated is around 196mV in peak at the cathodic contact as a response to a single pulse. When a train of laser pulses was applied at 100Hz, the peak voltage at the cathodic contact remained around 141mV suggesting the feasibility of this approach for applications with pulse frequencies up to 100Hz.
慢性组织对微电极植入物的反应是许多神经假体应用发展面临的主要挑战。长期的组织反应主要是由于互连部件的移动以及电极与周围神经组织之间产生的机械应力。远程激活的浮动微刺激器是消除互连部件的一种可能方法。作为向微刺激器传递能量的一种方法，我们提议使用近红外（NIR）波长的激光束。制造了各种尺寸的带有集成硅PIN光电二极管的FLAMES。尺寸范围从120（宽）x 300（长）x 100（高）微米到200 x 500 x 100微米。使用钛宝石激光器的850nm激发对器件进行了台架测试。为了测试这种方法，在用近红外激光束脉冲的盐溶液中对FLAMES的电压场进行了实验测试。作为对单个脉冲的响应，在阴极触点处产生的电压峰值约为196mV。当以100Hz施加一串激光脉冲时，阴极触点处的峰值电压保持在141mV左右，这表明这种方法对于高达100Hz脉冲频率的应用是可行的。
