Ultra Low Power Implantable Platform for Next Generation Neural Interfaces

半个多世纪以来，科学家们一直在记录清醒的动物大脑中神经元产生的微小电位，这些动物正在进行特定的行为，他们使用了大量耗电的设备。这些实验对大脑如何将感官信息表示和转化为控制有目的运动的信号产生了深刻的见解，并揭示了这个复杂系统如何受到神经损伤和疾病的影响。然而，直到最近，神经科医生可用的治疗途径一直局限于全身药物应用和神经外科损伤等粗略干预，近年来，已经开发出小型电子设备，通过植入神经系统的小电极传递特定模式的刺激。脑深部电刺激器和脑深部植入物等设备已经帮助了全世界成千上万的患者。下一代神经植入物将使用类似的电极来检测神经元的活动，为目前临床负担沉重的疾病的新疗法铺平道路。例如，通过利用大脑运动区神经元的活动来控制肌肉的电刺激，有可能使脊髓损伤瘫痪的患者恢复自主运动。然而，尽管电极技术取得了相当大的进步，但我们在单个神经元水平上将数字微电子器件与大脑连接起来的能力目前受到严重限制。每个电极都能检测到附近多个细胞发出的信号，它们产生的微小而短暂的“尖峰”事件在背景噪声下很难区分。为了解决这个问题，我们组建了一个跨学科的团队，他们在三个关键领域拥有专业知识：检测和分类尖峰事件所需的计算算法，执行实时、可靠尖峰识别的低功率集成电子器件，以及使用神经植入物记录大脑长期活动的技术，以评估现实世界的表现。其目的是提供一种平台技术，该技术将来自电极的原始信号转换为适合于传统数字微电子后续处理的识别尖峰事件流，并适合于并入一系列无线植入式设备。这种技术的可用性将彻底改变治疗各种神经系统疾病的设备的发展。

For over half a century scientists have recorded the tiny electrical potentials generated by neurons in the brains of awake animals performing specific behaviours, using large racks of power-hungry equipment. These experiments have yielded profound insights into how sensory information is represented and transformed by the brain into the signals that control purposeful movements, as well as revealing how this complex system is affected by neurological injuries and disease. However, until recently the therapeutic avenues available to neurologists have been limited to gross interventions such as systemic drug applications and neurosurgical lesions.In recent years, small electronic devices have been developed that deliver specific patterns of stimulation via small electrodes implanted in the nervous system. Devices such as Deep Brain Stimulators and Cochlear Implants have helped many thousands of patients worldwide. The next generation of neural implants will use similar electrodes to detect the activity of neurons, paving the way for new treatments for conditions that currently weigh a heavy clinical burden. For example, by using the activity of neurons in motor areas of the brain to control electrical stimulation of muscles, it is possible that voluntary movements could be restored to patients paralysed by spinal cord injuries. However, despite considerable advances in electrode technologies, our ability to interface digital microelectronics with the brain at the level of individual neurons is at present severely limited. Each electrode detects the signal from multiple cells in its vicinity, and the small, brief 'spike' events they generate can be hard to distinguish beneath the background noise.To solve this problem we have assembled a cross-disciplinary team with expertise in three key areas: the computational algorithms required to detect and sort spike events, low power integrated electronics to perform real-time, reliable spike identification, and the techniques to record long-term activity from the brain using neural implants in order to evaluate real-world performance. The aim is to deliver a platform technology that will convert the raw signal from electrodes into a stream of identified spike events suitable for subsequent processing by conventional digital microelectronics, and be suitable for incorporation into a range of wireless, implantable devices. The availability of such a technology would revolutionise the development of devices to treat a wide variety of nervous system disorders.