Bipolar handheld nerve locator and evaluator

Abstract

A hand-held disposable combination surgical nerve evaluator and locator is provided. The device includes a housing that serves as a handpiece and that accommodates a printed circuit board, a DC voltage source and a compressed gas source. Two pre-programmed settings are provided by way of a nerve evaluation switch and a nerve location switch. By choosing a nerve evaluation switch, a pulsed current is sent down one electrical lead that extends outward from the housing. A return electrical lead is provided that also extends outward from the housing in a parallel, but spaced-apart relationship from the other electrical lead. Compressed gas is delivered to the distal ends of the first and second electrical leads by a cannula that is connected to the compressed gas source. It will also be noted that the return or the second electrical lead can also serve as a cannula for the delivery of compressed gas. A fiber optic light guide may also be provided to illuminate the area around the distal ends of the two electrical leads. In a nerve evaluation mode, when the nerve evaluation switch has been activated, a pulsed current is delivered to the first electrical lead. Similarly, in a nerve location mode, a pulsed current is also delivered to the first electrical lead. However, the frequency of the pulsed current in the nerve evaluation mode is less than the frequency of the current in the nerve location mode, the pulse duration in the nerve evaluation mode is less than the pulse duration in the nerve location mode and the amplitude of the current in the nerve evaluation mode is less than the amplitude of the current in the nerve location mode.

1. A hand-held combination surgical nerve evaluator and locator comprising:
 a handpiece comprising a housing that accommodates a circuit board connected to a DC voltage source, the circuit board comprising a pulsed current source, the pulsed current source being connected to a first electrical lead, the housing also being connected to a second electrical lead, the first and second electrical leads extending outward from one end of the housing in a parallel and spaced-apart fashion, 
 the circuit board and pulsed current source being connected to a nerve evaluation on/off switch and a nerve location on/off switch, 
 movement of the nerve evaluation switch to an activation position causing a first pulsed current to be generated by the pulsed current source and transmitted to the first electrical lead, the first pulsed current having a nerve evaluation frequency, a nerve evaluation pulse duration and a nerve evaluation amplitude, 
 movement of the nerve location switch to an activation position causing a second pulsed current to be generated by the pulsed current source and transmitted to the first electrical lead, the second pulsed current having a nerve location frequency, a nerve location pulse duration and a nerve location amplitude, 
 the nerve evaluation frequency being less than the nerve location frequency, the nerve evaluation pulse duration being less than the nerve location pulse duration, and the nerve evaluation amplitude being less than the nerve location amplitude, 
 the second electrical lead serving as a ground. 
 
     
     
       2. The hand-held combination surgical nerve evaluator and locator of  claim 1  further comprising the nerve location frequency ranges from about 5 to about 9 Hz, the nerve location pulse duration ranges from about 300 to about 700 μsec, the nerve location amplitude ranges from about 700 to about 1100 ma mA, the nerve evaluation frequency ranges from about 1 to about 3 Hz, the nerve evaluation pulse duration ranges from about 150 to less than 300 μsec and the nerve evaluation amplitude ranges from about 150 to about 250 ma mA. 
     
     
       3. The hand-held combination surgical nerve evaluator and locator of  claim 1  further comprising a compressed gas source located within the housing and connected to the circuit board and a cannula connected to the compressed gas source, the cannula, the first electrical lead and the second electrical lead all comprising distal ends, the cannula extending outward from the one end of the housing and between the first and second electrical leads,
 movement of either the nerve location switch or the nerve evaluation switch to an activation position causing the compressed gas source to communicate pressurized gas through the cannula and between the distal ends of the first and second electrical leads. 
 
     
     
       4. The hand-held combination surgical nerve evaluator and locator of  claim 3  wherein the compressed gas source is a pump. 
     
     
       5. The hand-held combination surgical nerve evaluator and locator of  claim 4  wherein the pump is of a type selected from the group consisting of solenoid pump, diaphragm pump, rotary pump and vane pump. 
     
     
       6. The hand-held combination surgical nerve evaluator and locator of  claim 3  wherein the compressed gas source is a canister of compressed gas. 
     
     
       7. The hand-held combination surgical nerve evaluator and locator of  claim 6  wherein the compressed gas is selected from the group consisting of carbon dioxide, air, nitrogen and helium. 
     
     
       8. The hand-held combination surgical nerve evaluator and locator of  claim 1  further comprising a compressed gas source located within the housing and connected to the circuit board,
 and wherein the second electrical lead comprises a cannula connected to the compressed gas source, the first electrical lead and second electrical lead each comprising distal ends, the first electrical lead extending outward from the one end of the housing and through the second electrical lead, 
 movement of either the nerve location switch or the nerve evaluation switch to an activation position causing the compressed gas source to communicate pressurized gas through the second electrical lead and between the distal ends of the first and second electrical leads. 
 
     
     
       9. The hand-held combination surgical nerve evaluator and locator of  claim 8  wherein the compressed gas source is a pump. 
     
     
       10. The hand-held combination surgical nerve evaluator and locator of  claim 9  wherein the pump is of a type selected from the group consisting of solenoid pump, diaphragm pump, rotary pump and vane pump. 
     
     
       11. The hand-held combination surgical nerve evaluator and locator of  claim 5  wherein the second electrical lead comprises a distal end having at least one vent. 
     
     
       12. The hand-held combination surgical nerve evaluator and locator of  claim 1  further comprising a fiber optic light guide connected to the DC voltage source, the fiber optic light guide extending outward from the one end of the housing and along the first and second electrical leads. 
     
     
       13. The hand-held combination surgical nerve evaluator and locator of  claim 1  wherein the DC voltage source is a battery. 
     
     
       14. A method of locating a nerve in a patient comprising the following steps:
 providing a hand-held combination surgical nerve locator comprising a handpiece comprising a housing that accommodates a circuit board connected to the DC voltage source, the circuit board comprising a pulsed current source, the pulsed current source being connected to a first electrical lead, the housing also being connected to a second electrical lead, the second electrical lead serving as a ground, the first and second electrical leads extending outward from one end of the housing in a parallel and spaced-apart fashion, the circuit board and pulsed current source being connected to a nerve location switch, the housing also accommodating a compressed gas source which is connected to the circuit board and a cannula that is connected to the compressed gas source, the cannula, first electrical lead and second electrical lead all comprising distal ends, the cannula extending outward from the one end of the housing and between the first and second electrical leads, 
 engaging a patient with distal ends of the cannula and first and second electrical leads, 
 moving the nerve location switch to an activation position causing the compressed gas source to communicate pressurized gas through the cannula and between the distal ends of the first and second electrical leads thereby removing excess blood disposed between the first and second electrical leads and further causing a pulsed current to be generated by the pulsed current source and transmitted to the first electrical lead. 
 
     
     
       15. The method of  claim 14  wherein the compressed gas source is a pump. 
     
     
       16. The method of  claim 14  wherein the compressed gas source is a canister of compressed gas regulated by a switch. 
     
     
       17. The method of  claim 16  wherein the compressed gas is selected from the group consisting of carbon dioxide, air, nitrogen and helium. 
     
     
       18. The method of  claim 14  wherein the second electrical lead is the cannula connected to the compressed gas source. 
     
     
       19. The method of  claim 14  wherein the hand-held combination surgical nerve evaluator and locator further comprises a fiber optic light guide connected to the DC voltage source, the fiber optic light guide extending outward from the one end of the housing and along the first and second electrical leads,
 the method further comprising the step of illuminating and area around the distal ends of the cannula and first and second electrical leads with the fiber optic light guide. 
 
     
     
       20. The method of  claim 14  wherein the nerve location frequency ranges from about 5 to about 9 Hz, the nerve location pulse duration ranges from about 300 to about 700 μsec, the nerve location amplitude ranges from about 700 to about 1100 ma mA. 
     
     
       21. A method of evaluating a nerve in a patient comprising the following steps:
 providing a hand-held combination surgical nerve evaluator and locator comprising a handpiece comprising a housing that accommodates a circuit board connected to the DC voltage source, the circuit board comprising a pulsed current source, the pulsed current source being connected to a first electrical lead, the housing also being connected to a second electrical lead, the second electrical lead serving as a ground, the first and second electrical leads extending outward from one end of the housing in a parallel and spaced-apart fashion, the circuit board and pulsed current source being connected to a nerve evaluation switch, the housing also accommodating a compressed gas source which is connected to the circuit board and a cannula that is connected to the compressed gas source, the cannula, first electrical lead and second electrical lead all comprising distal ends, the cannula extending outward from the one end of the housing and between the first and second electrical leads, 
 engaging a patient with distal ends of the cannula and first and second electrical leads, 
 moving the nerve evaluation switch to an activation position causing the compressed gas source to communicate pressurized gas through the cannula and between the distal ends of the first and second electrical leads thereby removing excess blood disposed between the first and second electrical leads and further causing a pulsed current to be generated by the pulsed current source and transmitted to the first electrical lead. 
 
     
     
       22. The method of  claim 21  wherein the compressed gas source is a pump. 
     
     
       23. The method of  claim 21  wherein the second electrical lead is the cannula connected to the compressed gas source. 
     
     
       24. The method of  claim 21  wherein the hand-held combination surgical nerve evaluator and locator further comprises a fiber optic light guide connected to the DC voltage source, the fiber optic light guide extending outward from the one end of the housing and along the first and second electrical leads,
 the method further comprising the step of illuminating and area around the distal ends of the cannula and first and second electrical leads with the fiber optic light guide. 
 
     
     
       25. The method of  claim 21  wherein the nerve evaluation frequency ranges from about 1 to about 3 Hz, the nerve evaluation pulse duration ranges from about 150 to less than 300 μsec and the nerve evaluation amplitude ranges from about 150 to about 250 ma mA. 
     
     
       26. A hand-held combination surgical nerve evaluator and locator comprising:
 a handpiece comprising a housing that accommodates a circuit board connected to the a DC voltage source, the circuit board comprising a pulsed current source, the pulsed current source being connected to a first electrical lead, the housing also being connected to a second electrical lead, the first and second electrical leads extending outward from one end of the housing in a parallel and spaced-apart fashion, the housing also accommodating a compressed gas source connected to the circuit board and a cannula connected to the compressed gas source, the cannula, first electrical lead and second electrical lead all comprising distal ends, the cannula extending outward from the one end of the housing and between the first and second electrical leads, 
 the DC voltage source being connected to a fiber optic light guide that extends outward from the one end of the housing and along the first and second electrical leads, 
 the circuit board and pulsed current source being connected to a nerve evaluation switch and a nerve location switch, 
 movement of the nerve evaluation switch to an activation position causing a first pulsed current to be generated by the pulsed current source and transmitted to the first electrical lead, the first pulsed current having a nerve evaluation frequency, a nerve evaluation pulse duration and a nerve evaluation amplitude, 
 movement of the nerve location switch to an activation position causing a second pulsed current to be generated by the pulsed current source and transmitted to the first electrical lead, the second pulsed current having a nerve location frequency, a nerve location pulse duration and a nerve location amplitude, 
 movement of either the nerve location switch or the nerve evaluation switch to an activation position causing the compressed gas source to communicate pressurized gas through the cannula and between the distal ends of the first and second electrical leads and further causing the fiber optic light guide to illuminate the distal ends of the first and second electrical leads, 
 the nerve evaluation frequency being less than the nerve location frequency, the nerve evaluation pulse duration being less than the nerve location pulse duration, and the nerve evaluation amplitude being less than the nerve location amplitude, 
 the second electrical lead serving as a ground. 
 
     
     
       27. The hand-held combination surgical nerve evaluator and locator of  claim 26  wherein the second electrical lead is the cannula and the first electrical lead extends through the second electrical lead. 
     
     
       28. A cordless handheld nerve locator and evaluator device, the device comprising:
 first and second electrodes each having distal ends adjacent to each other and configured to be in contact with biological tissue;   a current source coupled to the first electrode and configured to generate an electrical stimulus; and   a control device configured to select operation of the current source in a first mode based solely on actuation of a first mode switch and a second mode based solely on actuation of a second mode switch, wherein   the current source is further configured to generate a first electrical stimulus in the first mode, the first electrical stimulus including a first frequency range, a first amplitude range, and a first pulse duration range,   the current source is further configured to generate a second electrical stimulus in the second mode, the second electrical stimulus including a second frequency range, a second amplitude range, and a second pulse duration range, and   the second frequency range is greater than the first frequency range, the second amplitude range is greater than the first amplitude range, and the second pulse duration range is greater than the first pulse duration range.   
     
     
       29. The device of claim 28, wherein the first electrode extends coaxially through at least a portion of the second electrode. 
     
     
       30. The device of claim 29, wherein the second electrode includes a cannula configured to direct gas flow to a region between the distal ends of the first and second electrodes. 
     
     
       31. The device of claim 30, wherein the cannula further comprises at least one vent configured to exhaust compressed gas flowing through the cannula. 
     
     
       32. The device of claim 30, wherein the cannula is disposed between the first electrode and the second electrode. 
     
     
       33. The device of claim 30, wherein the cannula is formed as the second electrode. 
     
     
       34. The device of claim 30, further comprising a gas source coupled to the cannula and configured to provide compressed gas in a region between the distal ends of the first and second electrodes. 
     
     
       35. The device of claim 34, wherein the control device is further configured to activate the gas source based on a selection of one of the first and second modes. 
     
     
       36. The device of claim 34, wherein the gas source contains a gas comprising any one of carbon dioxide, air, nitrogen, and helium. 
     
     
       37. The device of claim 34, wherein the gas source comprises a pump coupled to the cannula. 
     
     
       38. The device of claim 37, wherein the pump includes any one of a solenoid pump, diaphragm pump, rotary pump, and vane pump. 
     
     
       39. The device of claim 28, wherein the first mode includes a first current amplitude of 200 mA and the second mode includes a second current amplitude of 900 mA. 
     
     
       40. The device of claim 28, wherein the first mode includes a first pulse duration of 250 μs and the second mode includes a second pulse duration of 500 μs. 
     
     
       41. The device of claim 28, wherein the first mode includes a first frequency component of 2 Hz and the second mode includes a second frequency component of 7 Hz. 
     
     
       42. The device of claim 28, further comprising an optical light configured to provide illumination to at least a region between the distal ends of the first and second electrodes. 
     
     
       43. The device of claim 28, wherein the first mode includes a first frequency range from about 5 Hz to about 9 Hz. 
     
     
       44. The device of claim 28, wherein the first mode includes a first pulse duration range from about 300 μsec to about 700 μsec. 
     
     
       45. The device of claim 28, wherein the first mode includes a first amplitude range from about 700 mA to about 1100 mA. 
     
     
       46. The device of claim 28, wherein the second mode includes a second frequency range from about 1 Hz to about 3 Hz. 
     
     
       47. The device of claim 28, wherein the second mode includes a second pulse duration range from about 150 μsec to about 300 μsec. 
     
     
       48. The device of claim 28, wherein the second mode includes a second amplitude range from about 150 mA to about 250 mA. 
     
     
       49. The device of claim 28, further comprising a handheld housing configured to support at least one of the first and second electrodes. 
     
     
       50. The device of claim 50, wherein the housing includes a power source. 
     
     
       51. A method of locating and evaluating a nerve using a cordless handheld nerve locator and evaluator device, comprising:
 positioning the device to be in contact with biological tissue at a first position;   operating the device in a first mode to locate the nerve while the device is in contact with the biological tissue at the first position;   repositioning the device to be in contact with the biological tissue at a second position; and   operating the device in a second mode to evaluate the nerve while the device is in contact with the biological tissue at the second position, wherein   the device includes first and second electrodes each having distal ends adjacent to each other and configured to be in contact with the biological tissue, a current source coupled to the first electrode and configured to generate an electrical stimulus, and a control device configured to select operation of the current source in a first mode based solely on actuation of a first mode switch and a second mode based solely on actuation of a second mode switch,   the current source is further configured to generate a first electrical stimulus when operating the device in the first mode, the first electrical stimulus including a first frequency range, a first amplitude range, and a first pulse duration range,   the current source is further configured to generate a second electrical stimulus when operating the device in the second mode, the second electrical stimulus including a second frequency range, a second amplitude range, and a second pulse duration range, and   the second frequency range is greater than the first frequency range, the second amplitude range is greater than the first amplitude range, and the second pulse duration range is greater than the first pulse duration range.   
     
     
       52. The method of claim 51, further comprising
 flowing gas between the first electrode and the second electrode when operating the device in one of the first and second modes.   
     
     
       53. The method of claim 51, wherein operating the device in one of the first and second modes further includes illuminating the biological tissue.