Method and apparatus for an automatic setup of a multi-channel nerve integrity monitoring system

• US 6,181,961 B1
• Filed: 12/16/1998
• Issued: 01/30/2001
• Est. Priority Date: 12/16/1997
• Status: Expired due to Term

• Current Assignee: Richard L. Prass
• Original Assignee: Richard L. Prass
• Inventors: Prass, Richard L.
• Primary Examiner(s): Schaetzle, Kennedy
• Application Number:
  US09/212,380
• Time in Patent Office: 776 Days
• Field of Search: 607/2, 607/30, 607/48, 607/50, 607/51, 607/52, 607/59, 607/62, 607/140, 600/383, 600/547
• US Class Current: 600/547
• CPC Class Codes: A61B 2505/05 Surgical care
• CPC Class Codes: A61B 2560/029 adapted for auto-initiation
• CPC Class Codes: A61B 2562/063 in a linear array
• CPC Class Codes: A61B 2562/222 Electrical cables or leads therefor, e.g. coaxial cables or ribbon cables
• 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 5/4041 Evaluating nerves condition
• CPC Class Codes: A61B 5/4821 Determining level or depth of anaesthesia A61B5/1106 takes precedence
• CPC Class Codes: A61B 5/4893 Nerves
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes

Abstract

The invention provides a method and apparatus for connecting multiple electrodes into the receiving or head box portion of the nerve integrity monitor. The invention provides patient connection electrodes, their transmission lines and a manner by which these components may communicate to the main monitoring unit to actuate automatic setup functions and instructions. The “off-line” setup and diagnostic instructions are automatically initiated and annunciated to the main portion of the intraoperative nerve integrity monitor. The setup and diagnostic instructions are then automatically executed. The invention also provides patient connection electrodes with improved resistance to the deleterious effects of spurious electromagnetic artifacts. The invention is particularly applicable for use in monitoring facial electromyograhic (EMG) activity during surgeries in which a facial motor nerve is at risk due to unintentional manipulation, although it will be appreciated that the invention has broader applications and can be used in other neural monitoring procedures.

Claims

1. An apparatus for use in a nerve integrity monitoring system, comprising:

a plurality of electrodes connected to a transmission line that carries multiple data channels;

an impedance detection device that measures impedances during setup functions from the electrodes; and

a controller/interface that modifies parameters and outputs setup instructions to the nerve integrity monitoring system based upon input received from an operator and output received from the impedance detecting device.

2. The apparatus of claim 1, wherein the status of each electrode is detected by the impedance detection device and forwarded to the controller/interface, the controller interface determining a particular procedure to be performed by an operator of the nerve integrity monitoring system.

3. The apparatus of claim 2, wherein the impedance detection device determines the status of each electrode based on the whether each electrode is open, shorted, or registers a specific predetermined resistance.

4. The apparatus of claim 3, wherein when the impedance detection circuit measures zero impedance for an electrode that is shorted, the controller/interface initiates automatic setup functions.

5. The apparatus of claim 1, wherein one of the plurality of electrodes comprises a single patient ground electrode.

6. The apparatus of claim 1, wherein the plurality of electrode comprises at least three additional pairs of monitoring electrodes.

7. The apparatus of claim 1, further comprising:

a digital stimulator that receives setup instructions and parameters from the controller/interface based upon the pattern of impedances measured by the impedance detection device.

8. The apparatus of claim 1, further comprising:

a memory that stores a plurality of sets of setup instructions.

9. The apparatus of claim 8, wherein the impedance measurements received from the electrodes are communicated to the controller/interface, the controller/interface actuating an automatic setup of stimulus, recording and quantitative assessment parameters using one of the sets of setup instructions stored in the memory.

10. The apparatus of claim 9, wherein the memory is a non-volatile memory.

11. The apparatus of claim 1, further comprising:

a display device that displays diagnostics and setup parameters.

12. The apparatus of claim 11, wherein the impedance detection device measures the impedance of the electrodes and sends the impedance measurements to the display device for display.

13. The apparatus of claim 1, further comprising:

a speaker that audibly outputs diagnostic and setup information.

14. The apparatus of claim 1, further comprising, wherein patient information is transmitted from the electrodes to the a recording section of the nerve integrity monitoring system for storage in a memory.

15. The apparatus of claim 1, wherein when the nerve integrity monitoring system performs a diagnostic sequence, the controller/interface informs the operator and nerve integrity monitoring system of errors detected by the impedance detection device.

16. The apparatus of claim 15, wherein the errors detected include impedance mismatches and electrode disconnection among recording electrodes.

17. The apparatus of claim 15, further comprising:

an adapter that converts a single connection between the electrodes and the transmission line into a plurality of connections.

18. The apparatus of claim 15, wherein the impedance detection device immediately performs the electrode status check upon connection of the electrodes to the transmission line.

19. The apparatus of claim 1, wherein the electrodes are attached to a connector such that they make a single connection to the transmission line.

20. A method for operating a nerve integrity monitoring system, comprising:

connecting a plurality of electrodes to a transmission line that carries multiple data channels;

measuring impedances during setup functions from the electrodes; and

modifying parameters and outputting setup instructions to the nerve integrity monitoring system based upon input received from an operator and output received from the impedance detecting device.