Apparatus and methods for assessment of neuromuscular function

• US 5,976,094 A
• Filed: 02/12/1998
• Issued: 11/02/1999
• Est. Priority Date: 07/01/1997
• Status: Expired due to Term

• Current Assignee: Neurometrix, Inc.
• Original Assignee: Neurometrix, Inc.
• Inventors: Gozani, Shai N.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US09/022,990
• Time in Patent Office: 628 Days
• Field of Search: 600/483, 600/545, 600/546, 128/905
• US Class Current: 600/483
• CPC Class Codes: A61B 2505/05 Surgical care
• 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 5/1106 to assess neuromuscular blockade, e.g. to estimate depth of anaesthesia
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/395 Details of stimulation, e.g. nerve stimulation to elicit EMG response
• CPC Class Codes: A61B 5/4041 Evaluating nerves condition
• CPC Class Codes: A61B 5/6824 Arm or wrist
• CPC Class Codes: A61B 5/6825 Hand
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives

Abstract

Apparatus and methods are provided for the assessment of neuromuscular function. Using an apparatus of the invention, stimuli are applied to a nerve that traverses the wrist of an individual. The stimuli are applied at a point that is proximal to the wrist. Stimulation of the nerve causes a muscle innervated by that nerve to respond. The muscle response generates a myoelectric potential, which is detected by an apparatus of the invention at a point that is proximal to the wrist. The delay between stimulation of a nerve and detection of a muscular response to that stimulation is processed to indicate an assessment of neuromuscular function. For example, a sufficient delay between application of stimulus and muscle response may indicate the presence of Carpal Tunnel Syndrome.

Claims

1. An electrode configuration for assessing a physiological function in an arm and a hand of an individual, comprising:

(a) a stimulation electrode adapted for applying a stimulus proximal to a wrist of said individual; and

(b) a detection electrode in a fixed relationship with respect to said stimulation electrode and adapted for detecting proximal to said wrist a myoelectric potential generated by a muscle in said hand of said individual in response to said stimulus,

wherein a physiological function is evaluated in response to said stimulus and said myoelectric potential, and wherein said electrodes are sized and shaped for positioning on an anterior aspect of said arm of said individual proximal to said wrist.

2. The electrode configuration of claim 1, further comprising a temperature sensor for detecting a temperature of skin underlying said electrode configuration, wherein said physiological function evaluation is adjustable in response to said skin temperature.

3. The electrode configuration of claim 1, further comprising a reference electrode in electrical communication with said detection electrode and producing a reference potential.

4. The electrode configuration of claim 1, further comprising an electrode housing, wherein said stimulation electrode and said detection electrode are housed in said electrode housing so that a surface of each of said stimulation electrode and said detection electrode contacts skin of said individual underlying said electrode housing when said housing is located on said arm of said individual.

5. The electrode configuration of claim 4, further comprising an attachment mechanism for securing said electrode housing to said arm of said individual, wherein said electrode housing is adapted for placement on said arm of said individual proximal to said wrist.

6. The electrode configuration of claim 4, further comprising a second stimulation electrode, said second stimulation electrode being in a fixed relationship with respect to said stimulation electrode and said detection electrode, and being adapted for producing a stimulus and for applying said stimulus proximal to said wrist of said individual.

7. The electrode configuration of claim 6, wherein said stimulation electrode and said second stimulation electrode are positioned substantially at a center of said electrode housing.

8. The electrode configuration of claim 6, wherein said stimulation electrode and said second stimulation electrode are arranged within said electrode housing such that, when said electrode housing is placed on said anterior aspect of said arm, one of said stimulation electrodes is located immediately proximal to said wrist and the other of said stimulation electrodes is located at a position more proximal from said wrist.

9. The electrode configuration of claim 4, further comprising a second detection electrode, said second detection electrode being in a fixed relationship with respect to said stimulation electrode and said detection electrode and being adapted for detecting proximal to said wrist a myoelectric potential, whereby said myoelectric potential is generated by a muscle in a hand of said individual in response to said stimulus.

10. The electrode configuration of claim 9, wherein said detection electrode and said second detection electrode are arranged within said electrode housing such that, when said electrode housing is placed on said anterior aspect of said arm, one of said detection electrodes is located near a medial side of said arm and the other of said detection electrodes is located near a lateral side of said arm.

11. The electrode configuration of claim 4, wherein said electrode housing comprises a connector adapted for creating an electrical communication between each of said stimulation electrode and said detection electrode with a controller.

12. The electrode configuration of claim 4, wherein said electrode housing is disposable.