METHOD AND APPARATUS FOR MEASUREMENT OF NEURAL RESPONSE

• US 20140236042A1
• Filed: 05/11/2012
• Published: 08/21/2014
• Est. Priority Date: 05/13/2011
• Status: Abandoned Application

• Current Assignee: Saluda Medical Pty Ltd.
• Original Assignee: Saluda Medical Pty Ltd.
• Inventors: Parker, John Louis, Karantonis, Dean Michael
• Application Number:
  US14/117,145
• Publication Number:
  US 20140236042A1
• Time in Patent Office: Days
• US Class Current: 600/554
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/40 Detecting, measuring or recording for evaluating the nervous system A61B5/4806, A61B5/4821, A61B5/4824 take precedence
• CPC Class Codes: A61B 5/4041 Evaluating nerves condition
• CPC Class Codes: A61N 1/0456 Specially adapted for transcutaneous electrical nerve stimulation [TENS]
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/36135 using physiological parameters

Abstract

A method for estimating conduction velocity of a neural response. Measurements of the neural response are obtained from at least two electrodes which are at distinct locations along a neural pathway. A delay between the time of arrival of the neural response at each respective electrode is determined from the measurements. From the delay, and from knowledge of electrode spacing, a conduction velocity of the neural response is estimated.

Claims

1. A method for estimating conduction velocity of a neural response, the method comprising:

obtaining measurements of the neural response from at least two electrodes which are at distinct locations along a neural pathway;

determining a delay between the time of arrival of the neural response at each respective electrode; and

estimating from the delay, and from knowledge of electrode spacing, a conduction velocity of the neural response.

2. The method of claim 1 further comprising estimating, from the conduction velocity of the neural response, a proportion of fibre classes recruited to produce the neural response.

3. The method of claim 1 further comprising estimating, from changes in the conduction velocity of the neural response as detected from one measurement to a next measurement, a proportion of fibre classes recruited to produce the neural response.

4. The method of claim 2 further comprising using the estimated proportion of fibre classes recruited as an input to feedback control of an applied stimulus, in order to control the stimulus so as to preferentially recruit one or more desired fibre classes.

5. The method of claim 1, wherein the measurements of the neural response are obtained from locations both caudally of the stimulus site and rostrally of the stimulus site.

6. The method of claim 5 wherein a caudal conduction velocity and a rostral conduction velocity are each estimated from the measurements, and wherein the estimates are used as input to feedback control of the applied stimulus in order to effect differential control of fibre classes recruited in an evoked ascending volley as compared to fibre classes recruited in an evoked descending volley.

7. The method of claim 1 wherein the estimate of conduction velocity is used for feedback control of an applied stimulus in order to maintain stimulus efficacy during postural changes.

8. The method of claim 1 wherein the measurements of the neural response are obtained from at least three electrodes for each estimate of conduction velocity.

11. A method of claim 1 further comprising repeatedly measuring a neural conduction velocity over time and determining from said measurements whether changes in neural conduction velocity have occurred for diagnosing at least one disease which affects neural conduction velocity.

12. The method of claim 11 wherein the disease is diabetes mellitus, and wherein detection of a reduction in neural conduction velocity is used to trigger revision of a treatment schedule.

13. The method of claim 11 wherein the disease is central sensitization, the method further comprising obtaining a conduction velocity map of the spinal cord by progressively applying stimuli using each of a plurality of electrodes of an implanted electrode array, using spaced apart measurement electrodes to obtain a measure of the conduction velocity resulting from each stimulus site, and then mapping conduction velocity against location to indicate the location(s) at which central sensitization has occurred.

9. A device for estimating conduction velocity of a neural response, the device comprising:

at least two electrodes which are configured to be positioned at distinct locations along a neural pathway; and

a control unit configured to obtain measurements of the neural response from each electrode, the control unit further configured to determine a delay between the time of arrival of the neural response at each respective electrode, and the control unit further configured to estimate from the delay, and from knowledge of electrode spacing, a conduction velocity of the neural response.

10. The device of claim 9, wherein the device is configured for permanent implantation.