The Implantable Microstimulator
In 1988, funded by the Foundation and a grant from the National Institute of Health, joint research began with Illinois Institute of Technology and Queens University in Canada, to develop a magnetically controlled and powered injectable neuromuscular stimulation device for impaired neural and muscular functions. This exciting technology has been transferred to Advanced Bionics Corporation who having worked with the Foundation has brought this technology to the public for the treatment of migraine headache and urinary incontinence.

Clinical Studies to Improve and Restore Function
THE FOUNDATION has repackaged the original magnetically controlled and powered microstimulator in a ceramic case (RFM). Although, not intended to be commercialized, the RFM is a useful research device for testing the safety and efficacy of such a device in the treatment stroke patients and other conditions.

In 2001 a feasibility clinical study was initiated at Brigham and Women’s Hospital in Boston with Dr. David White to determine if individuals suffering from sleep apnea could benefit from microstimulator therapy. Two patients have been implanted with the device proving that there is potential device has possibility.

In 2003 a study with stroke patients was initiated in England at the University of Southampton under the direction of Dr. Jane Burridge, using the same RFM microstimulator. Forty-five devices were implanted in subject with the intent to restoring function to paralyzed upper limbs. Between 5 and 7 microstimulators were implanted on the nerve or motor point of the affected muscles in each of seven patients to exercise the limb. The study demonstrated that exercising the paralyzed limb with these devices for 2 hours per day for 12 weeks, significantly reduced the severity of the spasticity in several of the patients, and partially reduced the severity of the spasticity in the remainder of the patients. All patients were partially paralyzed for over a year as a result of their stroke. Normally they would not have expected any improvement after this long period. Based on the results of this study, it is expected that if patients continue the use of the device to enhance the function of partially paralyzed limbs for daily activities they would all obtain significant improvements. It was also noted that partially paralyzed muscles in the same limb that were implanted with a microstimulator device did not show improvement. We may be able to improve all the affected muscles by implanting each with a microstimulator device.

New Product Development, the Injectable Microstimulator System
In the US alone, 4.6 million people suffer from stoke and as many as 30% of these patients are presently paralyzed. In 1999, more than 1,100 000 American adults reported difficulty with functional limitations, activities of daily living, etc, resulting from stroke (SIPP).

To address this need the R&D team at the foundation is developing a system of battery powered injectable microstimulators and microsensors, each of which can be controlled and monitored up to 100 times a second via radio communication. This system is intended to restore function to partially paralyzed limbs. For a stroke patient with partial paralysis, it will appear to as though he has regained control of the limb. The foundation hopes to make the process of injecting the devices a simple office procedure, reducing the cost of an out patient, surgical procedure.

In addition, to bring this technology to market, the Foundation and Bioness are working together on this, the next generation microstimulator. This exciting device will be powered by rechargeable batteries and will communicate with others like it through a wireless network. Together they will restore function to patients with severe neuromuscular impairments through coordinated sensing and stimulation. Through a joint Foundation and Bioness program, clinical investigators are being recruited to research the vast potential of these devices so that this exciting technology may be rapidly available to the public.