Artifact detection electrode

• US 7,310,546 B2
• Filed: 05/26/2006
• Issued: 12/18/2007
• Est. Priority Date: 11/06/2001
• Status: Expired due to Term

• Current Assignee: Richard L. Prass
• Original Assignee: Richard L. Prass
• Inventors: Prass, Richard L.
• Primary Examiner(s): Hindenburg; Max F.
• Assistant Examiner(s): Foreman; Jonathan
• Application Number:
  US11/441,481
• Publication Number:
  US 20060217610A1
• Time in Patent Office: 571 Days
• Field of Search: 600372-385, 600/544, 600/546, 600/509
• US Class Current: 600/373
• CPC Class Codes: A61B 5/0531 Measuring skin impedance
• 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 5/4821 Determining level or depth of anaesthesia A61B5/1106 takes precedence
• CPC Class Codes: A61B 5/4893 Nerves
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker

Abstract

An intraoperative neurophysiological monitoring system includes an adaptive threshold detection circuit adapted for use in monitoring with a plurality of electrodes placed in muscles which are enervated by a selected nerve and muscles not enervated by the nerve. Nerve monitoring controller algorithms permit the rapid and reliable discrimination between non-repetitive electromyographic (EMG) events and repetitive EMG events, thus allowing the surgeon to evaluate whether nerve fatigue is rendering the monitoring results less reliable and whether anesthesia is wearing off. An artifact detection electrode provides a reliably detectable impedance imbalance between the electrode leads and antenna-like qualities for enhanced detection of current and electromagnetic artifacts.

Claims

1. An artifact detection electrode for sensing neurophysiological signal artifacts in tissue structures, in the body, comprising:

a first electrode needle having an insulated proximal portion and a sharp, uninsulated distal portion;

a second electrode needle having an insulated proximal portion and a sharp, uninsulated distal portion;

an electrically conductive, first elongate wire lead having a proximal end, an intermediate portion and a distal end;

an electrically conductive, second elongate wire lead having a proximal end, an intermediate portion and a distal end;

said first elongate wire lead being electrically connected to said first electrode needle proximal portion at said first elongate wire lead distal end;

said second elongate wire lead being electrically connected to said second electrode needle proximal portion at said second elongate wire lead distal end;

said first elongate wire lead having a circuit element connected in series therewith along said intermediate portion of said first elongate wire lead; and

said first elongate wire lead intermediate portion and said second elongate wire lead intermediate portion being configured in a loop to define a recording field signal receiving antenna.

2. The artifact detection electrode of claim 1, said circuit element being a circuit element for creating a detectable impedance imbalance.

3. The artifact detection electrode of claim 1, said first elongate wire lead and said second elongate wire lead being twisted together distally and proximally of said loop, said loop being defined by segments of said first and second elongate wire leads which are not twisted together.

4. An artifact detection electrode for sensing neurophysiological signal artifacts in tissue structures, in the body, comprising:

a first electrode needle having an insulated proximal portion and a sharp, uninsulated distal portion;

a second electrode needle having an insulated proximal portion and a sharp, uninsulated distal portion;

a first elongate conductor having a proximal end, an intermediate portion and a distal end;

a second elongate conductor having a proximal end, an intermediate portion and a distal end;

said first elongate conductor being electrically connected to said first electrode needle proximal portion at said first elongate conductor distal end;

said second elongate conductor being electrically connected to said second electrode needle proximal portion at said second elongate conductor distal end;

said first elongate conductor having a circuit element connected in series therewith, said first elongate conductor having said circuit element connected in series in said first elongate conductor intermediate portion; and

said first elongate conductor intermediate portion and said second elongate conductor intermediate portion being configured in a loop to define a recording field signal receiving antenna.

5. An artifact detection electrode for sensing neurophysiological signal artifacts—

in tissue structures, in the body, comprising;

a first electrode needle having an insulated proximal portion and a sharp, uninsulated distal portion;

a second electrode needle having an insulated proximal portion and a sharp, uninsulated distal portion;

a first elongate conductor having a proximal end, an intermediate portion and a distal end;

a second elongate conductor having a proximal end, an intermediate portion and a distal end;

said first elongate conductor being electrically connected to said first electrode needle proximal portion at said first elongate conductor distal end;

said second elongate conductor being electrically connected to said second electrode needle proximal portion at said second elongate conductor distal end;

said first elongate conductor having a circuit element connected in series therewith, said first elongate conductor having said circuit element disposed in a connector body affixed to said proximal end of said first elongate conductor; and

said first elongate conductor intermediate portion and said second elongate conductor intermediate portion being configured in a loop to define a recording field signal receiving antenna.

6. An artifact detection electrode for sensing neurophysiological signal artifacts in tissue structures, in the body, comprising:

a first electrode needle having an insulated proximal portion and a sharp, uninsulated distal portion,

a second electrode needle having an insulated proximal portion and a sharp, uninsulated distal portion;

a first elongate conductor having a proximal end, an intermediate portion and a distal end;

a second elongate conductor having a proximal end, an intermediate portion and a distal end;

said first elongate conductor being electrically connected to said first electrode needle proximal portion at said first elongate conductor distal end;

said second elongate conductor being electrically connected to said second electrode needle proximal portion at said second elongate conductor distal end;

said first elongate conductor having a resistive circuit element connected in series therewith, said resistive circuit element being a fixed value resistor; and

said first elongate conductor intermediate portion and said second elongate conductor intermediate portion being configured in a loop to define a recording field signal receiving antenna.

7. An artifact detection electrode for sensing neurophysiological signal artifacts in tissue structures, in the body, comprising:

a first electrode needle having an insulated proximal portion and a sharp, uninsulated distal portion;

a second electrode needle having an insulated proximal portion and a sharp, uninsulated distal portion;

a first elongate conductor having a proximal end, an intermediate portion and a distal end;

a second elongate conductor having a proximal end, an intermediate portion and a distal end;

said first elongate conductor being electrically connected to said first electrode needle proximal portion at said first elongate conductor distal end;

said second elongate conductor being electrically connected to said second electrode needle proximal portion at said second elongate conductor distal end;

said first elongate conductor having a resistive circuit element connected in series therewith, said resistive circuit element being a variable resistance potentiometer; and

said first elongate conductor intermediate portion and said second elongate conductor intermediate portion being configured in a loop to define a recording field signal receiving antenna.

8. The artifact detection electrode for sensing neurophysiological signal artifacts of claim 7, said variable resistance potentiometer having an adjustment range of from zero ohms to approximately fifty thousand ohms.