Remote generation of electrical signal in tissue for leadless neurostimulation.
Every organ in the body can be influenced by a nerve. Stimulation of tissue within the body by electrical energy sources connected to electrode/lead wire systems is becoming a new powerful means for treatment of numerous diseases. The use of lead wires is associated with significant problems such as complications due to infection, lead failure, and electrode/lead dislodgement. The use of leads to accomplish tissue stimulation also limits the number of accessible locations in the body, as well as the ability to stimulate tissue at multiple sites (multisite stimulation). For instance, the treatment of epilepsy may require a minimum of perhaps 5 or 6 stimulation sites. Other diseases, such as Parkinson's disease, may benefit from more stimulation sites than the two utilized in current systems.
We have experimentally demonstrated in the model studies that the TRA ultrasound focusing system may remotely generate several volts electrical signal in a piezotransducer embedded in the tissue. Wireless neurostimulator devices activated by the TRA ultrasound focusing system can be used for treatment of illnesses in many parts of the human body by sending necessary signals to a nerve controlling certain organ or function in the body. The neurostimulators based on our propritary wireless TRA technology may be applicable for treatment for a great variety of diseases such as epilepsy, depression, post-stroke paralysis, migraines, sleep apnea, angina, obesity, impotence, digestive tract disorders, bladder incontinence, obsessive-compulsive disorder, chronic pain, Alzheimer's disease and other brain ailments. Another application of the technology may be energizing implanted miniature drug pumps. In this way, a patient could be dosed exactly when needed and at the precise site where the medication is most effective. This could reduce dosages by a thousandfold and avert side effects.
The technology encompasses a method of TRA focusing with remote feedback from the focal point in the form of electromagnetic waves generated by a miniature piezotransducer implanted in the target area and affected by the primary acoustic wave. Once the primary acoustic wave transmission causes energizing of such piezoelectric transducer, it generates an electromagnetic signal reproducing exactly the waveform of the received acoustic wave, which is then received by an external receiving antanna. This received signal is then used by an external ultrasound system to “home-in” the acoustic waves on the implanted miniature piezotransducer using Time-Reversal principles.