Bi-level charge pulse apparatus to facilitate nerve location during peripheral nerve block procedures
First Claim
1. An electrolocation apparatus comprising a needle cannula having opposed proximal and distal ends and a lumen extending therebetween, said needle cannula being formed to define first and second conductors electrically insulated from one another;
- and a stimulator connected to the respective conductors on the needle cannula and operative to generate high and low charge pulses of electrical energy, and wherein said stimulator comprises a current source coupled to one of said respective conductors on said needle cannula;
path means, connected between the other of said respective conductors on said needle cannula and ground, for completing a current path passing through said needle cannula;
pulsing means, connected to said path means, for turning said current on and off to produce charge pulses through said needle cannula, said pulsing means comprising;
a transistor, connected between said needle cannula and said path means, for controlling charge conduction in said current path and through said needle cannula;
gating means, coupled to the base of said transistor, for providing base current thereto for turning conduction through said transistor on and off;
counter means, connected to said gating means, for determining the timing of the base current provided to said transistor by said gating means; and
means for controlling said counter means to regulate the timing of said base current in turning conduction of said transistor on and off to produce alternating high and low charge pulses across said needle cannula.
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Accused Products
Abstract
An electrolocation apparatus is provided for locating a nerve to which anesthesia may be delivered. The apparatus includes a needle assembly having an electrically conductive needle cannula non-conductive tube secured over the needle cannula, and a conductive plating on the tube. The conductors are connected to a stimulator that generates alternating high and low charge pulses with a constant low current level. The high charge pulses generate noticeable muscle twitches immediately after insertion of the needle into the patient. Muscle twitches responsive to the high charge pulses will peak in magnitude, and muscle twitches responsive to the low charge pulses will become observable as the needle approaches the targeted nerve, and will be indistinguishable from the muscle twitches responsive to the high charge pulses when the needle is in a position for administration of anesthetic.
494 Citations
7 Claims
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1. An electrolocation apparatus comprising a needle cannula having opposed proximal and distal ends and a lumen extending therebetween, said needle cannula being formed to define first and second conductors electrically insulated from one another;
- and a stimulator connected to the respective conductors on the needle cannula and operative to generate high and low charge pulses of electrical energy, and wherein said stimulator comprises a current source coupled to one of said respective conductors on said needle cannula;
path means, connected between the other of said respective conductors on said needle cannula and ground, for completing a current path passing through said needle cannula; pulsing means, connected to said path means, for turning said current on and off to produce charge pulses through said needle cannula, said pulsing means comprising; a transistor, connected between said needle cannula and said path means, for controlling charge conduction in said current path and through said needle cannula; gating means, coupled to the base of said transistor, for providing base current thereto for turning conduction through said transistor on and off;
counter means, connected to said gating means, for determining the timing of the base current provided to said transistor by said gating means; and
means for controlling said counter means to regulate the timing of said base current in turning conduction of said transistor on and off to produce alternating high and low charge pulses across said needle cannula. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- and a stimulator connected to the respective conductors on the needle cannula and operative to generate high and low charge pulses of electrical energy, and wherein said stimulator comprises a current source coupled to one of said respective conductors on said needle cannula;
Specification