In an exemplary embodiment, the simultaneous intensity control of the individual current circuits is to be effected while avoiding undesired intensity deviations in the current circuits such as occur because of nonuniformity of multiple potentiometers, for example. Expediently, the signal frequencies are digitally generated. According to the disclosure, in every output current circuit a transistor is connected-in, which is switched between a conducting and a nonconducting condition so that the collector output exhibits either a zero value or an operating voltage value, all switching transistors being activated on the collector side via a common control element from a single voltage source. In the through-connected state, the collector voltages of the switching transistors have the same value, respectively, which can be synchronously varied in dependence upon the setting of common control element.
A multiple site drug iontophoresis electronic device configured for controlling infusion of ionic drugs into a patient through a plurality of electrode pairs. The device includes a plurality of electrode driver channels wherein each driver channel includes an electrode output configured for electrical connection to at least one of the plurality of electrode pairs through lead wires. Each driver channel is electrically isolated from the other driver channels and includes an independent current sink which controls current intensity through the electrode output. A common controller operates the driver channels as a function of treatment parameters supplied by the patient.
Apparatus for multi-channel transverse epidural spinal cord stimulation uses a multi-channel pulse generator driving a plurality of electrodes mounted near the distal end of a lead. These electrodes are mounted in one or more lines, generally perpendicular to the lead axis, and have a planar surface along one surface of the lead. The lead is implanted adjacent to spinal cord dura mater with the electrodes transverse and facing the spinal cord. Pulses generated by the pulse generator for each channel are normally simultaneous, of equal amplitude and of equal duration, however the pulse generator is arranged such that pulses for each channel can selectably alternate in time, can selectably be of unequal amplitude, or both. The changes in pulse timing and magnitude permit shifting the electrical stimulation field and the resulting paresthesia pattern after installation to accommodate improper lead placement or postoperative dislocation and to minimize unwanted motor responses.
The present invention involves a method of treating a patient by providing a signal that is exponential in character to the patient. The signal includes a relatively low-frequency, constant amplitude, periodic-exponential first component. Further, the signal preferably includes a relatively high-frequency, periodic-exponential second component.
The present invention provides an electrotherapeutic apparatus that produces a signal that, upon application to a patient, is exponential in character. The signal includes a relatively low-frequency, constant amplitude, periodic-exponential signal for muscle stimulation. Further, the signal preferably includes a relatively high-frequency, periodic-exponential signal for sensory stimulation.
Apparatus for multi-channel transverse epidural spinal cord stimulation uses a multi-channel pulse generator driving a plurality of electrodes mounted near the distal end of a lead. These electrodes are mounted in one or more lines, generally perpendicular to the lead axis, and have a planar surface along one surface of the lead. The lead is implanted adjacent to spinal cord dura mater with the electrodes transverse and facing the spinal cord. Pulses generated by the pulse generator for each channel are not simultaneous but are selectively offset in time and may be of equal or varying amplitude and of equal or varying duration. When the pulses given by the stimulator channels are offset in time and have sufficient amplitude and duration, overlapping areas of stimulation of the spinal area can be obtained. In the overlapping areas of stimulation, the frequency of stimulation is double the frequency of the pulses given by the each stimulator channel separately. Changes in pulse duration and magnitude permit shifting the electrical stimulation field and the resulting paresthesia pattern after installation to accommodate improper lead placement or postoperative dislocation and to minimize unwanted motor responses.
