SYSTEM AND METHOD FOR MAPPING ACTIVITY IN PERIPHERAL NERVES

• US 20110046506A1
• Filed: 08/20/2010
• Published: 02/24/2011
• Est. Priority Date: 08/20/2009
• Status: Active Grant

• Current Assignee: Case Western Reserve University
• Original Assignee: Case Western Reserve University
• Inventors: Wodlinger, Brian, DURAND, DOMINIQUE M.
• Granted Patent: US 9,636,239 B2
• Time in Patent Office: Days
• US Class Current: 600/547
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/388 Nerve conduction study, e.g. detecting action potential of peripheral nerves
• CPC Class Codes: A61B 5/4029 for evaluating the peripheral nervous systems A61B5/24 takes precedence
• CPC Class Codes: A61B 5/4041 Evaluating nerves condition
• CPC Class Codes: A61B 5/4064 Evaluating the brain A61B5/031, A61B5/369, A61B5/14553 take precedence
• CPC Class Codes: A61F 2/72 Bioelectric control, e.g. myoelectric
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/36003 of motor muscles, e.g. for walking assistance
• CPC Class Codes: A61N 1/36103 Neuro-rehabilitation; Repair or reorganisation of neural tissue, e.g. after stroke
• CPC Class Codes: G06F 30/20 Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30

Abstract

Systems and methods are provided for controlling an entity in response to activity in a peripheral nerve comprising a plurality of fascicles. A multicontact electrode assembly is configured to record activity from the peripheral nerve. A processing component includes a sensor mapping component configured to quantify activity associated with a proper subset of the plurality of fascicles, an evaluation component configured to determine an adjustment of the status of the controlled entity from the quantified activity of the proper subset of the plurality of fascicles, and a controller configured to provide a control signal, representing the adjustment of the status of the controlled entity, to the controlled entity.

Claims

1. A system for controlling an entity in response to activity in a peripheral nerve comprising a plurality of fascicles comprising:

a multicontact electrode assembly configured to record activity from the peripheral nerve;

a processing component comprising;

a sensor mapping component configured to quantify activity associated with a proper subset of the plurality of fascicles;

an evaluation component configured to determine an adjustment of the status of the controlled entity from the quantified activity of the proper subset of the plurality of fascicles; and

a controller configured to provide a control signal, representing the adjustment of the status of the controlled entity, to the controlled entity.

2. The system of claim 1, the sensor mapping component being configured to map the recorded activity at the peripheral nerve as a representation of a cross section of the peripheral nerve, such that the activity at individual fascicles of the nerve can be determined.

3. The system of claim 2, the sensor mapping component being configured to map the recorded activity at the peripheral nerve as a representation comprising a temporal component, such that at least one of the direction and the speed of the neural activity can be determined.

4. The system of claim 2, the sensor mapping component being configured to represent the activity measured at the multi-contact electrode as a vector of voltages and multiply the vector of voltages by a transformation matrix representing the spatial sensitivity of the peripheral nerve.

5. The system of claim 4, the sensor mapping component being configured to construct a filter associated with at least one fascicle as a linear combination of a plurality of vectors from the transformation matrix.

6. The system of claim 1, the sensor mapping component being configured to quantify activity from at least two fascicles and determine a custom filter for a given fascicle from the quantified activity for the at least two fascicles.

7. The system of claim 1, the controlled entity comprising at least one of an external assistive device, and implanted medical device, and a prosthetic limb, the controller comprising an interface for providing a command to the controlled entity in an appropriate format.

8. The system of claim 7, the evaluation component configured to determine an event class associated with a given command from the quantified activity and provide the command according to the determined event class.

9. The system of claim 1, the controlled entity comprising the peripheral nerve, and the controller being configured to produce a stimulation pattern for the multicontact electrode assembly.

10. The system of claim 9, wherein the evaluation component is configured to monitor reflex activity in the peripheral nerve in response to the stimulation pattern.

11. The system of claim 1, the controlled entity comprising a second peripheral nerve, and the controller being configured to produce a therapeutic stimulation pattern for a second multicontact electrode assembly.

12. A method for modeling a spatial sensitivity of a multicontact electrode assembly comprising:

determining respective sets of voltages for a plurality of contacts associated with the multicontact electrode assembly, each set of voltages representing the voltages at a plurality of locations on a test model when a known voltage is applied to its associated contact; and

determining, from the sets of voltages for the plurality of contacts, a set of weights representing each location on the test model, such that a given set of weights represents the presence of an ideal point source at the location associated with the set of weights given the measured sets of voltages.

13. The method of claim 12, wherein determining a set of weights representing each location on the test model comprises calculating the set of weights in a linear least squares optimization, with the sets of voltages for the plurality of contacts utilized as predictor variables and a delta function, representing the ideal point source, utilized as a response variable.

14. The method of claim 12, further comprising concatenating the sets of weights into a transformation matrix, such that the product of the transformation matrix and a set of clinical voltages measured at the multicontact electrode assembly provides an expected spatial distribution of voltage across the plurality of locations.

15. The method of claim 12, wherein the test model is simulated as a homogenous epineurium immersed in saline.

16. A method for sensing activity within a peripheral nerve, said method comprising:

contacting a multi-contact electrode assembly with the peripheral nerve;

recording a voltage at a plurality of contacts associated with the multicontact electrode assembly as a set of voltages; and

multiplying the set of voltages by a transformation matrix to provide a voltage at each of plurality of locations on the peripheral nerve.

17. The method of claim 16, further comprising:

locating a position of at least one of a plurality of fascicles in the peripheral nerve according to the voltage determined at the plurality of locations;

determining a set of weights associated with the position of the at least one fascicle, representing a relative voltage at each of a set of the plurality of locations associated with the at least one fascicle; and

constructing a filter associated with the at least one fascicle as a linear combination of a plurality of vectors from the transformation matrix, each vector being associated with one of the plurality of locations associated with the at least one fascicle and each vector being weighted in the linear combination by a weight from the set of weights that represent its associated location.

18. The method of claim 16, wherein recording a voltage each of a plurality of contacts associated with the multicontact electrode assembly comprises recording a first set of voltages when a first source is active and determining a second set of voltages when a second source is active, the method further comprising constructing a filter, configured to increase an accuracy of measurement when the first source is active, from the first set of voltages and the second set of voltages.

19. The method of claim 16 further comprising:

repeating the steps of recording a voltage from a plurality of contacts and multiplying the set of voltages by a transformation matrix as to provide the voltage at a plurality of locations on the peripheral nerve over a period of time.

20. The method of claim 16, further comprising controlling at least one of a medical implant, a prosthetic limb, an external assistance device, the multicontact electrode assembly, or a different multicontact electrode assembly.