In the United States, over 100,000 deep brain stimulation (DBS) devices have been implanted to date for treatment of basic tremor, Parkinson's disease and dystonia, and clinical trials are underway to evaluate indications for chronic pain, severe depression, migraines and dimentia. DBS devices belong to a class of devices called implantable electrical stimulators, and close to 1 Million of these devices are implanted annually. These devices use electrodes in contact with tissue to deliver electrical pulses to targeted cells, to elicit specific therapeutic responses. Devices must be replaced as batteries wear down, thus improvements in device efficiency will extend device lifetime and reduce the number of replacement surgeries. While effective in many cases, DBS shows limited effectiveness in others and also has side effects. Preclinical studies predict that DBS arrays comprised of many densely packed, small electrodes can precisely target brain stem region to improve therapy. In general, the neuromodulation industry has been evolving towards smaller, less invasive electrodes. Thus, there are strong clinical, engineering and power motivations for moving towards smaller electrodes. However, current electrode materials do not support small sizes without severely restricting the stimulus output. Hence, an improved electrode material will benefit present and future DBS systems. Platinum Group Coatings LLC has developed a cost-effective and materials-efficient process for applying an ultra-low impedance platinum-iridium alloy coating onto the contacts of DBS stimulator electrodes. If successful, this coating will enable next generation stimulation devices by allowing for significantly smaller electrodes to provide the same or enhanced performance. Additionally, this process will enable microfabricated leads on flex-circuit substrates. This phase-I research will perform a feasibility study of these coatings for the DBS device application. The objectives for phase I include deposition of a variety of PtIr films on clinical DBS electrodes, electrical and mechanical evaluation of the films, and long-term pulsing of modified electrodes. Standard electrochemical techniques and surgical implant methods (in a brain model) will be used for evaluation.
DBS devices belong to a class of devices called implantable electrical stimulators, and close to 1 Million of these devices are implanted annually. These devices use electrodes in contact with tissue to deliver electrical pulses to targeted cells, to elcit specific therapeutic responses. Improved electrode materials are proposed that will increase the lifetime of current implants and enable realization of a new generation of implants with advanced features which promise better patient outcomes.