Microprocessor-controlled multiplexed functional electrical stimulator for surface stimulation in paralyzed patients
First Claim
1. An electrical stimulation system, for coupling to a plurality of electrodes coupled to locations at the right and left side of a lower part of the body of a patient, said system comprising:
- pulse generator means for selectively outputting trains of pulses having selectively variable duration and pulse repetition frequency responsive to a control signal;
memory for storing operational instructions and data;
control means for selectively outputting said control signal responsive to said memory and to input commands;
pulse amplifier means for selectively amplifying pulse amplitude and power responsive to said control means;
multiplexer means for selectively multiplexing outputs of said pulse amplifier means from said pulse generator means and alternatively between selected ones of said electrodes responsive to said control means;
a battery power supply;
wherein said electrodes are wired in pairs as channels, wherein there are at least 4 channels, one adapted contact to the right quadriceps muscle, one to the left quadriceps muscle, one to the right common peroneal nerve and one to the left common peroneal nerve.
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Accused Products
Abstract
In accordance with the present invention, a functional electrical stimulation system enables upper-motor-neuron paraplegic patients and certain other paralyzed or partially paralyzed patients to stand and to take steps with the support of a walker in an independent fashion so that they are in control of the stimulation and, noting that they have very little or not sensation, that they still can obtain some feedback on the state of the system. In one embodiment, a compact and safe battery-operated stimulation system is provided that is of pocket size and that allows for non-invasive safe and controlled stimulation using skin surface electrodes.
The system of the present invention is a stimulation system for providing upper-motor-neuron paralyzed patients with capabilities of unbraced standing and unbraced walking, which consists of a single pulse power and amplifier that outputs various trains of stimulation pulses and which is totally under microprocessor generation and control, where the microprocessor'"'"'s microcomputer selectively performs multiplexing of the pulse trains and their selective alternate distribution to the various surface electrodes attached to the skin of the patient at the appropriate stimulation locations. It also controls pulse-width, pulse-duration, pulse-amplitude and pulse-shape.
Furthermore, the system can compute and activate (audible and/or visual) warning signals to warn the patient when the system is close to its maximal output. This would happen when muscle fatigue is such that no further increase in stimuli level can keep the patient upright. The system computes and outputs indications of the various stimuli levels to a visual display, and it provides automatic fail-safe and override capabilities to help ensure that the patient does not fall in case of major circuit or system failure or misactivation. This is a critical capability since this sytem will be used by paraplegics who lack sensation in their lower extremities.
51 Citations
95 Claims
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1. An electrical stimulation system, for coupling to a plurality of electrodes coupled to locations at the right and left side of a lower part of the body of a patient, said system comprising:
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pulse generator means for selectively outputting trains of pulses having selectively variable duration and pulse repetition frequency responsive to a control signal; memory for storing operational instructions and data; control means for selectively outputting said control signal responsive to said memory and to input commands; pulse amplifier means for selectively amplifying pulse amplitude and power responsive to said control means; multiplexer means for selectively multiplexing outputs of said pulse amplifier means from said pulse generator means and alternatively between selected ones of said electrodes responsive to said control means; a battery power supply; wherein said electrodes are wired in pairs as channels, wherein there are at least 4 channels, one adapted contact to the right quadriceps muscle, one to the left quadriceps muscle, one to the right common peroneal nerve and one to the left common peroneal nerve. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 95)
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53. An electrical stimulation system, for coupling to a plurality of electrodes coupled to locations at the right and left side of the lower part of the body of a patient, said system comprising:
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pulse generator means for selectively outputting trains of pulses having selectively variable duration and pulse repetition frequency responsive to a control signal; memory means for storing operational instructions and data; control means for selectively outputting said control signal responsive to said memory and to input commands; pulse amplifier means for selectively amplifying pulse amplitude and power responsive to said control means; multiplexer means for selectively multiplexing outputs of said pulse amplifier means from said pulse generator and alternatively between selected ones of said electrodes responsive to said control means; and
a battery power supply and a portable casing within which said system is mounted,wherein said pulse generator means and said control means are further characterized as comprising a single microcomputer, and an Analog to Digital Converter (ADC), wherein said microcomputer selectively outputs through said ADC a single pulse train to said pulse amplifier means, wherein said pulse amplifier means is comprised of a single pulse amplifier, wherein the output of the pulse amplifier means is multiplexed to distribute its output to at least 4 channels, wherein the multiplexer means is further comprised of solid state switch devices, wherein said control means switches modes of operation responsive to said input command means to provide a "stand" mode, a "take left step" mode, a "take right step" mode, and a "sit down" mode, wherein the levels of said pulse trains are ramped at an initial "stand" mode stand-up from an initial "sit-down" mode sit position, wherein at a subsequent "sit-down" mode the levels of said pulse trains decreases to zero in a ramp manner to avoid sudden cessation of power, wherein said microcomputer receives said input commands from both an external switching array mounted on a patient support device that is coupled by a coupling to said casing enclosing said microcomputer, pulse amplifier, ADC and multiplexer, and, from a switching array mounted on said casing, wherein switching input commands are coupled from said external array including two sets of switches, one mounted on the right side of patient'"'"'s support device and one mounted on the left side of same, wherein said right side switches include one step switch to select command of "take right step" and one level switch to select command of both increasing pulse level for right quadriceps and for increasing pulse level for producing a right step, wherein increasing of pulse level for right quadriceps is commanded by a single short pressing of said level switch, wherein each such pressing produces a fixed increment increase in pulse level, and wherein a long duration pressing of said level switch beyond a predetermined duration selects a command to increase level of pulse to the common peroneal nerve to produce a step, wherein said left side switches do the same respectively for the left quadriceps and left step, wherein switching to command sit down is performed by long duration pressing for a duration longer than some predetermined duration, of a selected switch, and wherein once said sit down has been commanded, said control means delays execution of sit down command for a different predetermined time duration. - View Dependent Claims (79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94)
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Specification