programmable stimulus generator and multielectrode array to investigate new electrical stimulation protocols for relief from seizure-like activity

对癫痫的研究表明，哺乳动物癫痫发作时的脑电活动可以通过施加电刺激来抑制。研究表明，对癫痫样活动的抑制随刺激频率的变化而变化；在低频率下，抑制作用缓慢，但刺激去除后效果持久，而在高频率下，缓解是立即的，但持续时间不长。这次合作已经证实了这些数据。该设备最初将用于研究大鼠海马组织对混合频率电刺激的癫痫样活动的反应。通过将一个以上的频率混合到电刺激信号中，预期可以观察到高频和低频的好处。这是一项重要的研究，因为“尽管通过在大脑中植入电极来刺激不受控制的癫痫已经进行了多年，但迄今为止所做的很少的临床研究尚未证实最初声称的治疗成功。刺激的最佳结构和最有效的刺激是未知的。”（《柳叶刀：神经病学》2004年第3卷，第111-118页）。这项研究将进一步了解抑制癫痫样发作活动背后的过程，并有助于完善类似电路的神经连接模型。该设备对于寻求使用“片上系统”技术开发具有集成预放大和/或模数转换硬件的电极阵列的长期项目也至关重要。这种设备的增强旨在显著提高信噪比。随着神经组织逐渐受到电极植入和电刺激的影响，这对神经研究界来说是一个重要的支持步骤。从本质上讲，我们正试图帮助电生理学家比目前更快地获得有用的数据。这对电气工程专业的学生来说是一个极好的机会，因为他们可以接触到一个令人兴奋的跨学科研究环境。

Studies of epilepsy have characterized the electrical activity associated with the onset of seizures in mammals and can be suppressed via the application of an electrical stimulus. It has been shown that the suppression of seizure-like activity varies with the stimulus frequency; at low frequencies the suppression is slow to take effect, but the effect is long-lasting after the stimulus is removed whereas at higher frequencies relief is immediate but does not last as long. This collaboration has already confirmed such data.    The equipment requested in this grant will initially be used to investigate the response of epileptic seizure-like activity in rat hippocampal tissue to a mixed-frequency electrical stimulus. By mixing more than one frequency into the electrical stimulus signal it is anticipated that the benefits of both high and low frequencies may be observed. This is an important study as "Although stimulation for uncontrolled epilepsy with electrodes implanted in the brain itself has been done for many years, the initial claims for therapeutic success have not been confirmed by the very few clinical studies that have been done so far. The best structures to stimulate and the most effective stimuli to use are unknown." ("The Lancet: Neurology", Vol. 3, 2004, pp.111-118). This investigation will take steps to understand the processes behind the suppression of epileptic seizure-like activity and help refine models of neural connectivity that resemble electrical circuits.    The equipment is also critical to longer-term projects that seek to use "system-on-chip" technology to develop electrode arrays with integrated pre-amplification and/or analog-digital conversion hardware. Such enhancements to this equipment are aimed at significantly improving signal/noise ratios. This is an important supporting step for the bresearch community as the neural tissue is gradually affected by the implantation of electrodes and the presence of the electrical stimulus. In essence we are trying help electrophysiologists to obtain useful data quicker than at present. This represents an excellent opportunity for electrical engineering students as they are exposed to an exciting interdisciplinary research environment.