Nerve stimulator output control needle with depth determination capability and method of use

Claim 2

A nerve stimulator needle apparatus comprising: a needle capable of carrying an electric current; a variable control mechanism which is operable to variably control the amplitude of an application of electric current to said needle during a procedure using said needle; a plurality of electrical connectors connected to said variable control mechanism and said needle which allows said variable control mechanism to remotely connect to a nerve stimulation device which is operable to provide a voltage to said variable control mechanism and to provide a current pulse to said needle having an amplitude which is controlled by said variable control mechanism; and a housing which holds said variable control mechanism, said plurality of electrical connectors and said needle, wherein an electrically resistive layer covers said needle, the resistance of said resistive layer changes with the length of said resistive layer, and an electrical trace from an electrical pin connector provides a voltage to said electrically resistive layer from said nerve stimulator device.

Claim 3

The nerve stimulator needle apparatus of claim 1 , wherein said needle is a hypodermic needle, said apparatus further comprising: an injection tube operably connected to said needle to provide a fluid to said needle.

Claim 4

The nerve stimulator needle apparatus of claim 2 , wherein said housing includes a fluid path, and said injection tube is connected to one end of said fluid path and said needle is connected to another other end of said fluid path.

Claim 5

The nerve stimulator needle apparatus of claim 1 , wherein said variable control mechanism includes a pressure sensitive switching mechanism which changes the amplitude of said current applied to said needle in relation to the amount of pressure applied to said pressure sensitive switching mechanism.

Claim 6

The nerve stimulator needle apparatus of claim 1 , wherein said variable control mechanism is operable to increase or decrease current to the needle.

Claim 7

The nerve stimulator needle apparatus of claim 1 , wherein said variable control mechanism is operable to control a rate of change of the current.

Claim 8

The nerve stimulator needle apparatus of claim 1 , wherein said housing further includes conductive traces which connect said variable control mechanism and said needle to said electrical connectors.

Claim 9

The nerve stimulator needle apparatus of claim 1 , wherein the variable control mechanism is operable to variably control the amplitude of an application of electric current to said needle during a procedure using said needle on a subject based on feedback from the subject.

Claim 10

The nerve stimulator needle apparatus of claim 1 , wherein said needle further includes an insulating layer between said electrically resistive layer and said needle.

Claim 11

A nerve stimulator needle apparatus comprising: a needle capable of carrying an electric current; a variable control mechanism which is operable to variably control the amplitude of an application of electric current to said needle during a procedure using said needle; a plurality of electrical connectors connected to said variable control mechanism and said needle which allows said variable control mechanism to remotely connect to a nerve stimulation device which is operable to provide a voltage to said variable control mechanism and to provide a current pulse to said needle having an amplitude which is controlled by said variable control mechanism; and a housing which holds said variable control mechanism, said plurality of electrical connectors and said needle, wherein said needle further includes an insulating layer between an electrically resistive layer and said needle.

Claim 12

A nerve stimulator needle apparatus comprising: a needle capable of carrying an electric current; a variable control mechanism which is operable to variably control the amplitude of an application of electric current to said needle during a procedure using said needle; a plurality of electrical connectors connected to said variable control mechanism and said needle which allows said variable control mechanism to remotely connect to a nerve stimulation device which is operable to provide a voltage to said variable control mechanism and to provide a current pulse to said needle having an amplitude which is controlled by said variable control mechanism; and a housing which holds said variable control mechanism, said plurality of electrical connectors and said needle, wherein said needle further includes an insulating layer between an electrically resistive layer and said needle.

Claim 13

A nerve stimulator apparatus comprising: a nerve stimulator device comprising: a voltage source; a controller; and a current source operable to produce an electrical current in response to said controller; and a needle unit remotely located from said nerve stimulator device and connected to said nerve stimulator device only by at least one electrical conductor, said needle unit comprising: a variable control mechanism which is operable to receive a voltage from said voltage source and to provide instructions to said controller to variably control the amplitude of said electrical current provided by said current source during a procedure using said needle unit; a needle capable of carrying said electric current from said current source having the amplitude controlled by said variable control mechanism; and a housing which holds said variable control mechanism and said needle, wherein said needle unit includes an electrically resistive layer covering said needle, wherein the resistance of said resistive layer changes with the length of said resistive layer, and an electrical trace from an electrical connector provides a voltage from said voltage source to said electrically resistive layer.

Claim 14

A nerve stimulator apparatus comprising: a nerve stimulator device comprising: a voltage source; a controller; and a current source operable to produce an electrical current in response to said controller; and a needle unit remotely located from said nerve stimulator device and connected to said nerve stimulator device only by at least one electrical conductor, said needle unit comprising: a variable control mechanism which is operable to receive a voltage from said voltage source and to provide instructions to said controller to variably control the amplitude of said electrical current provided by said current source during a procedure using said needle unit; a needle capable of carrying said electric current from said current source having the amplitude controlled by said variable control mechanism; and a housing which holds said variable control mechanism and said needle, wherein said needle unit includes an electrically resistive layer covering said needle, wherein the resistance of said resistive layer changes with the length of said resistive layer, and an electrical trace from an electrical connector provides a voltage from said voltage source to said electrically resistive layer.

Claim 15

The nerve stimulator apparatus of claim 11 , wherein said needle is a hypodermic needle, said apparatus further comprising: an injection tube operably connected to said needle to provide a fluid to said needle.

Claim 16

The nerve stimulator apparatus of claim 12 , wherein said housing includes a fluid path, and said injection tube is connected to one end of said fluid path and said needle is connected to another other end of said fluid path.

Claim 17

The nerve stimulator apparatus of claim 11 , wherein said variable control mechanism includes a pressure sensitive switching mechanism which changes the amplitude of said current applied to said needle in relation to the amount of pressure applied to said pressure sensitive switching mechanism.

Claim 18

The nerve stimulator apparatus of claim 11 , wherein said current source is operable to increase or decrease current in response to the operation of said variable control mechanism, and said variable control mechanism is operable to increase or decrease current to the needle.

Claim 19

The nerve stimulator apparatus of claim 11 , wherein the current source changes the amplitude of said current in response to the operation of said variable control mechanism and said variable control mechanism is operable to control the rate of change of the current.

Claim 20

The nerve stimulator apparatus of claim 11 , further comprising electrical connectors mounted to said housing, wherein the electric current is provided through said electrical connectors.

Claim 21

The nerve stimulator apparatus of claim 17 , wherein said housing further includes conductive traces which connect said variable control mechanism and said needle to said electrical connectors.

Claim 22

The nerve stimulator apparatus of claim 11 , wherein said needle unit further includes an insulating layer between said electrically resistive layer and said needle.

Claim 23

The nerve stimulator apparatus of claim 11 , wherein said controller includes a microprocessor, and said microprocessor determines the insertion depth of the needle according to the equation: L b =( R t −R a ) / r L where R a is the resistance of the portion of the needle protruding above a skin surface of a subject; R t is the resistance of the total length of the needle; r L is the resistance per unit length of the needle; and L b is the insertion depth of the needle.

Claim 24

The nerve stimulator apparatus of claim 20 , wherein the value R a is calculated from the ratio of the applied voltage to the resistive layer on the needle divided by the current detected by a return electrode attached to the surface of the skin of a subject.

Claim 25

The nerve stimulator apparatus of claim 11 , wherein the variable control mechanism is operable to variably control the amplitude of an application of electric current to said needle during a procedure using said needle on a subject based on feedback from the subject.

Claim 26

A nerve stimulator apparatus comprising: a nerve stimulator device comprising: a voltage source; a controller; and a current source operable to produce an electrical current in response to said controller: and a needle unit remotely located from said nerve stimulator device and connected to said nerve stimulator device only by at least one electrical conductor, said needle unit comprising: a variable control mechanism which is operable to receive a voltage from said voltage source and to provide instructions to said controller to variably control the amplitude of said electrical current provided by said current source during a procedure using said needle unit; a needle capable of carrying said electric current from said current source having the amplitude controlled by said variable control mechanism; and a housing which holds said variable control mechanism and said needle, wherein said needle unit further includes an insulating layer between an electrically resistive layer and said needle.

Claim 27

A nerve stimulator apparatus comprising: a nerve stimulator device comprising: a voltage source; a controller; and a current source operable to produce an electrical current in response to said controller: and a needle unit remotely located from said nerve stimulator device and connected to said nerve stimulator device only by at least one electrical conductor, said needle unit comprising: a variable control mechanism which is operable to receive a voltage from said voltage source and to provide instructions to said controller to variably control the amplitude of said electrical current provided by said current source during a procedure using said needle unit; a needle capable of carrying said electric current from said current source having the amplitude controlled by said variable control mechanism; and a housing which holds said variable control mechanism and said needle, wherein said needle unit further includes an insulating layer between an electrically resistive layer and said needle.

Claim 30

The method of locating nerves according to claim 24 , wherein the step of determining the needle insertion depth is performed according to the equation: L b =( R t −R a ) / r L where R a is the resistance of the portion of the needle protruding above a skin surface of a subject; R t is the resistance of the total length of the needle; r L is the resistance per unit length of the needle; and L b is the insertion depth of the needle.

Claim 31

The method of locating nerves according to claim 25 , wherein the value R a is calculated from the ratio of the applied voltage to the resistive layer on the needle divided by the current detected by the return electrode attached to the surface of the skin of a subject.

Claim 32

The method of locating nerves according to claim 24 , wherein the step of activating a variable control mechanism to provide a variably controlled current to said needle variably controls the current to said needle based on feedback from the subject.