Electro-nerve stimulator systems and methods

Abstract

An electro-nerve stimulator system includes a pulse generator for generating current pulses with a transcutaneous patch and percutaneous needle for delivering current pulses to selected stimulation sites. The stimulator is a small battery operated external device that allows adjustment of stimulation levels and interfaces, via a connector, to the trans-percutaneous cable. The transcutaneous electrode is attached to the skin distal from the desired stimulated nerve site. A percutaneous needle is inserted close to the internal nerve site. Stimulation current pulses are designed to flow between the transcutaneous electrode and the internal percutaneous needle. The field generated at the needle site causes the nerve to fire.

1 . An apparatus for electro-nerve stimulation, the apparatus comprising: 
 a pulse generator,    a transcutaneous electrode electrically coupled to the pulse generator for delivering pulses from the pulse generator to a patient's skin, and    a percutaneous electrode electrically coupled to the pulse generator and having an end for insertion into a patient's body in proximity to an internal stimulation site to receive pulses from the transcutaneous electrode.    
     
     
         2 . The apparatus of  claim 1 , wherein the transcutaneous electrode includes a layer of a highly conductive metal.  
     
     
         3 . The apparatus of  claim 2 , wherein the highly conductive metal is silver.  
     
     
         4 . The apparatus of  claim 1 , wherein the pulse generator is a current source and generates current pulses.  
     
     
         5 . The apparatus of  claim 1 , wherein the pulse generator includes a DC blocking capacitor electrically coupled to the transcutaneous electrode.  
     
     
         6 . The apparatus of  claim 5 , wherein the pulse generator further includes a discharge path for the DC blocking capacitor.  
     
     
         7 . The apparatus of  claim 6 , wherein the discharge path includes an active circuit.  
     
     
         8 . The apparatus of  claim 7 , wherein the active circuit includes a switch for providing a momentary discharge path across the DC blocking capacitor and a switch activation means for activating the switch in synchronization with the current pulses.  
     
     
         9 . The apparatus of  claim 8 , wherein the discharge path includes a passive circuit.  
     
     
         10 . The apparatus of  claim 9 , wherein the passive circuit includes a resistor electrically coupled to the DC blocking capacitor to provide a discharge path for the DC blocking capacitor.  
     
     
         11 . The apparatus according to  claim 10 , wherein the DC blocking capacitor has a selected capacitance and the resistor has a selected resistance such that the time constant of the resistor coupled to the capacitor results in discharge of the capacitor between the pulses without causing substantial degradation of the pulses.  
     
     
         12 . The apparatus of  claim 5 , wherein the pulse generator further comprises 
 a battery for providing current,    oscillator circuit means electrically coupled to the battery for providing current pulses,    pulse shaping means electrically coupled to the oscillator circuit means for shaping the current pulses from the oscillator circuit means,    DC-DC step up voltage means electrically coupled to the battery and the DC blocking capacitor for changing a DC voltage provided by the battery, and    feedback control means electrically coupled to the percutaneous needle and to the pulse shaping means for adjusting the current.    
     
     
         13 . An apparatus for electro-nerve stimulation, the apparatus comprising: 
 a pulse generator having a first lead interface and a second lead interface,    a first lead wire having a first end and a second end, the first end being electrically coupled to the first lead interface of the pulse generator,    a transcutaneous electrode electrically coupled to the second end of the first lead wire for delivering current pulses from the pulse generator to a patient's skin,    a second lead wire having a first end and a second end, the first end being electrically coupled to the second lead interface of the pulse generator, and    a percutaneous electrode having a first end electrically coupled to the second end of the second lead wire, and having a second end for insertion into a patient's body in proximity to an internal stimulation site to receive pulses from the transcutaneous electrode.    
     
     
         14 . The apparatus of  claim 13 , wherein the transcutaneous electrode is fixedly coupled to the second end of the first lead wire.  
     
     
         15 . The apparatus of  claim 13 , wherein the transcutaneous electrode is removably and replaceably coupled to the second end of the first lead wire.  
     
     
         16 . The apparatus of  claim 14 , wherein the first end of the first lead wire and the first end of the second lead wire are configured to prevent concurrent coupling of the first lead wire to the second lead interface and of the second lead wire to the first lead interface.  
     
     
         17 . A percutaneous electrode for electro-nerve stimulation, comprising: 
 an electrically-conductive shaft member having a first end configured to receive nerve stimulating pulses and having a second end configured for insertion into a patient's body in proximity to an internal stimulation site, the second end of the shaft member terminating in an electrically conductive tip portion, and a portion of the second end of the shaft member proximate the tip portion being coated with an electrically-insulating layer to prevent substantial passage of pulses to tissue surrounding the stimulation site.    
     
     
         18 . The percutaneous electrode of  claim 17 , wherein the tip portion has a length of between about 0.5 mm to about 10 mm.  
     
     
         19 . The percutaneous electrode of  claim 17 , wherein the tip portion has a length of about 2 mm.  
     
     
         20 . The percutaneous electrode of  claim 17 , wherein the insulting layer is formed from a synthetic resin polymer.  
     
     
         21 . The percutaneous electrode of  claim 17 , further comprising a handle portion coupled to the first end of the shaft member for allowing manipulation of the needle by a user.  
     
     
         22 . A method for electro-nerve stimulation, comprising the steps of: 
 providing an apparatus for electro-nerve stimulation, the apparatus including 
 a pulse generator,  
 a transcutaneous electrode electrically coupled to the pulse generator for delivering pulses from the pulse generator to a patient's skin, and  
 a percutaneous electrode electrically coupled to the pulse generator and having an end for insertion into a patient's body in proximity to an internal stimulation,  
   placing the transcutaneous electrode on a patient's skin distal to the stimulation site,    penetrating the skin of a patient with the percutaneous electrode, and    advancing the percutaneous electrode into proximity with the stimulation site, and    activating the generator to generate pulses that traverse the internal stimulation site between the transcutaneous electrode and the percutaneous electrode.    
     
     
         23 . A kit for use with a pulse generator for electro-nerve stimulation, the kit comprising: 
 a first lead wire having a first end and a second end, the first end being electrically coupled to the first lead interface of the pulse generator,    a transcutaneous electrode electrically coupled to the second end of the first lead wire for delivering current pulses from the pulse generator to a patient's skin,    a second lead wire having a first end and a second end, the first end being electrically coupled to the second lead interface of the pulse generator, and    a percutaneous electrode having a first end electrically coupled to the second end of the second lead wire, and having a second end for insertion into a patient's body in proximity to an internal stimulation site to receive pulses from the transcutaneous electrode.    
     
     
         24 . A kit for use with a pulse generator for electro-nerve stimulation, the kit comprising: 
 a transcutaneous electrode electrically coupled to the pulse generator for delivering pulses from the pulse generator to a patient's skin, and    a percutaneous electrode electrically coupled to the pulse generator and having an end for insertion into a patient's body in proximity to an internal stimulation site to receive pulses from the transcutaneous electrode.