An independently rate-adjustable multiple channel controller-transmitter for a nerve stimulator to be used in conjunction with an implanted stimulation pulse output unit includes a rate generating circuit (40,41,43,44) for producing asynchronous trigger signals of independently adjustable rate and width, a transmitting circuit (46,47,48,49) for generating bursts of RF energy at separate frequencies in response to the trigger signals, and a rate control circuit (50) for preventing excitation of the transmitting circuit by more than one trigger signal at a time. In the event that two or more trigger signals coincide at the transmitting circuit (46,47,48,49), the rate control circuit (50) blocks and delays the latter occurring trigger signals with only minor and insignificant effect on trigger signal rate.
A system for controlling bladder evacuation includes first and second implanted stimulation systems having electrodes respectively positioned on nerves controlling external sphincter and bladder functions, and an electronic control system which operates to generate and transmit electrical sphincter stimulation pulses to the first stimulation system. When it is desired to evacuate the bladder, a switch is closed causing the electronic control system to discontinue the external sphincter stimulation and, after a predetermined delay, to generate and transmit electrical bladder stimulation pulses to the second stimulation system. After a predetermined time, the bladder stimulation is automatically stopped. After another predetermined delay, the electronic control system resumes the generation and transmission of sphincter stimulation pulses to the first stimulation system.
A group of muscles, particularly the glutei, is stimulated electrically by the application of at least one pair of electrodes (18, 19; 20, 21) to the group and the supply of a symmetrically alternating voltage through the electrodes for equal periods of time (A) separated by intervals (B) of predetermined equal duration. In each period of time (A), the alternating voltage has a periodic behaviour with pulses of equal duration (PD) and alternating polarity symmetrical in adjacent half periods and separated by intervals (I) of equal duration. Each period (A) in which the alternating voltage is applied has a duration of between 0.5 and 1.5 s, and the intervals between the periods (A) are between 0.8 and 2 s long. The frequency of the alternating voltage is between 100 and 200 Hz, preferably 150 Hz. Each half period (T/2) in which the voltage is applied includes a pulse having a duration (PD) of between 40 and 60% of the half period.
A computer based system and methods for use with known neuromodulation systems to assist in the performance of pre-, intra- and post-operative procedures relating to the determination and optimization of a patient's therapeutic regimen. The system can use a computer database of information in connection with the pain map of an individual patient to aid the physician in making more accurate decisions regarding waveform and electrode configuration definition, as well as multi-electrode lead placement. The system can record and process patient responses to test stimulation patterns during the operation of placing the electrodes, so as to give the physician real-time information that can be used to effectively position the multi-electrode leads within the patient's body. The system also provides computer assisted post-operative presentation and assessment of stimulation settings, which utilizes, at least in one mode of operation, an iterative, systematic approach to determining one or more optimum stimulation settings.
A method and apparatus are provided for electrically stimulating muscle of individuals having little or no nerve damage so the muscle can be power contracted with little pain to the individual. A therapeutic current is applied to the muscle which includes alternating desensitizing and stimulus currents. The desensitizing current is a high frequency, low amplitude current to desensitize the muscle and the stimulus current is a low frequency, high amplitude current to stimulate the muscle. The currents alternate at a point where the amplitude and slope of the two currents are substantially identical to avoid abruptions in the current. An onset failure monitor circuit is also provided to detect an increase in skim/electrode impedance indicative of possible subsequent failure of the skin-electrode connection or electrode failure.
An electronic stimulation system is used to control pain over multiple regions of a patient's body. The system has one or more percutaneous leads, each having multiple electrodes, implanted within the patient's epidural space parallel to the axis of the spinal cord. The leads are connected to either a totally implanted system or a radio frequency system. The system is able to treat pain over different regions of a patient's body by "simultaneously" stimulating the patient with at least three different stimulation settings. "Simultaneous" stimulation involves sequentially stimulating the patient with the multiple stimulation settings such that the patient receives the cumulative effect of each stimulation setting, while not perceiving the transition from one stimulation setting to another.