Positioning system for a nerve stimulator needle

• US 20040059247A1
• Filed: 09/03/2003
• Published: 03/25/2004
• Est. Priority Date: 09/04/2002
• Status: Active Grant

• Current Assignee: William F. Urmey
• Original Assignee: William F. Urmey
• Inventors: Urmey, William F.
• Granted Patent: US 7,282,033 B2
• Time in Patent Office: Days
• US Class Current: 600/554
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/4893 Nerves
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 90/11 with guides for needles or instruments, e.g. arcuate slides or ball joints

Abstract

A target nerve or nerve plexus registration point is located utilizing a nerve stimulator needle positioned in a bore of a carrier. The carrier is configured with an electrically nonconductive smooth curved surface at a distal end of the bore. The needle tip is fixed in an operative cutaneous electrode position and the smooth curved surface of the carrier is forced against and compresses the epidermis, corium and subcutaneous tissue and traverses cutaneous surfaces to locate a target nerve or nerve plexus without physical penetration by the needle tip. The needle is then inserted at the located point, with or without the needle path being guided by the bore. In another embodiment, a subcutaneous portion of carrier is introduced and is pivoted about its introduction point to locate the target nerve.

Claims

1. A positioning system for cutaneously locating a target nerve or nerve plexus of a subject, the system comprising a carrier, a bore extending through the carrier, the bore having a proximal end and a distal end, the carrier having a surface with a smooth contour at the distal end of the bore, the surface being electrically nonconductive, a needle carried in the bore, the needle having a tip, the needle tip being selectively coupled to a current supply for eliciting a neurological response to current flow, the needle tip being in an operative cutaneous electrode position whereby current flow from the tip through the subject is assured when the surface is pressed against dermal layers of the subject without invasive penetration of the tip.

2. A positioning system as constructed in accordance with claim 1 wherein a portion of the carrier is in engagement with the needle to releasably maintain the needle tip in the operative cutaneous electrode position.

3. A positioning system as constructed in accordance with claim 2 wherein the needle includes a groove which is engaged by a portion of the carrier to releasably maintain the needle tip in the operative cutaneous electrode position.

4. A positioning system as constructed in accordance with claim 2 wherein the needle includes a hub and a shaft, the shaft being engaged by a portion of the carrier to releasably maintain the needle tip in the operative cutaneous electrode position.

5. A positioning system as constructed in accordance with claim 2 wherein the needle includes a hub and a shaft, the hub being engaged by a portion of the carrier to releasably maintain the needle tip in the operative cutaneous electrode position.

6. A positioning system as constructed in accordance with claim 2 wherein the portion of the carrier in engagement with the needle comprises a set screw.

7. A positioning system as constructed in accordance with claim 2 wherein the portion of the carrier in engagement with the needle comprises a pin.

8. A positioning system as constructed in accordance with claim 1 wherein the carrier includes an axial slot extending from the bore and the needle includes a radial arm, the slot including at least one notch formed along a longitudinal edge thereof, the notch being dimensioned to receive the radial arm to releasably maintain the needle tip in the operative cutaneous electrode position.

9. A positioning system as constructed in accordance with claim 1 wherein the bore comprises a first bore, the carrier having a second bore, the first bore and the second bore being coaxial, the second bore extending from the proximal end of the first bore, the needle including a proximal end and a distal end, the tip being positioned at the distal end of the needle and a hub being positioned at the proximal end of the needle, the second bore being dimensioned to receive the hub.

10. A positioning system as constructed in accordance with claim 1 wherein the carrier includes an axial slot extending from the bore and the needle includes a radial arm received in the slot, whereby the radial arm may be employed for advancing the needle into the subject after the target nerve or nerve plexus has been located.

11. A positioning system for locating a target nerve or nerve plexus of a subject, the system comprising a carrier, a bore extending through the carrier, the bore having a proximal end and a distal end, the carrier having a surface with a smooth contour at the distal end of the bore, the surface being electrically nonconductive, a needle carried in the bore, the needle having a tip, the tip being selectively coupled to a current supply, the tip having an operative position in proximity to the surface sufficient to assure current flow through the subject for eliciting a neurologic response which varies as a function of the position of the surface relative to the target nerve or nerve plexus.

17. A positioning system for locating a target nerve or nerve plexus of a subject constructed in accordance with claim 11 wherein the carrier includes a subcutaneous portion and a grip portion, the portions being cylindrical in shape and separated by a radial step, the bore extending through both portions, the grip portion having a larger diameter than the subcutaneous portion and the subcutaneous portion including the distal end of the bore.

12. A method of locating a target nerve or nerve plexus of a patient for the administration of an anesthetic blockade or other medical procedure, the method comprising the steps of:

a) providing a carrier having a bore and an electrically nonconductive smooth surface at an end of the bore,

b) placing a needle having a tip within the bore,

c) positioning the tip in proximity to the end of the bore,

d) coupling a current supply to the tip,

e) initiating current flow through the patient from the tip,

f) moving the end of the bore while maintaining current flow;

g) ascertaining a position of the carrier in registration with the target nerve or nerve plexus by eliciting a neurological response to current flow during step f) and

h) fixing the carrier at the ascertained position.

13. A method of administering an anesthetic blockade in accordance with claim 12 including the further steps of:

i) advancing the tip beyond the end of the bore and toward the target nerve or nerve plexus, and

j) detecting when the tip is properly positioned by observing when the maximal neural response is attained at the minimum current level.

14. A method of locating a target nerve or nerve plexus for the administration of an anesthetic blockade or other medical procedure in accordance with claim 12 wherein the step of f) is practiced while applying a compressive force against dermal layers of the patient.

15. A method of administering an anesthetic blockade in accordance with claim 14 including the further steps of:

i) advancing the tip beyond the end of the bore and toward the target nerve or nerve plexus, and

j) detecting when the tip is properly positioned by observing when the maximal neural response is attained at the minimum current level.

16. A method of administering an anesthetic blockade in accordance with claim 12 including the further steps of:

i) removing the carrier from the ascertained position, and

j) advancing a needle into the patient at the ascertained position.

20. A method of administering an anesthetic blockade in accordance with claim 12 wherein step f) is practiced in the absence of a coupling gel.

18. A method of administering an anesthetic blockade or other medical procedure to a patient, the method comprising the steps of:

a) providing a needle having a tip,

b) coupling a current supply to the tip,

c) initiating current flow through the patient from the tip by noninvasively contacting dermal layers of the patient with the tip,

d) varying the point of contact between the tip and the dermal layers,

e) ascertaining a point of contact in registration with a target nerve or nerve plexus by eliciting a neurological response to current flow during step d) and

f) advancing the needle into the patient at the ascertained point of contact.

19. A method of administering an anesthetic blockade or other medical procedure to a patient in accordance with claim 18 wherein step d) is practiced in the absence of a coupling gel.