Electromyography system

Abstract

A method of determining relative neuro-muscular response onset value thresholds for a plurality of spinal nerves, comprising: depolarizing a portion of the patient's cauda equina; and measuring the current intensity level at which a neuro-muscular response to the depolarization of the cauda equina is detected in each of the plurality of spinal nerves. A method for detecting the presence of a nerve adjacent the distal end of at least one probe, comprising: determining relative neuro-muscular response onset values for a plurality of spinal nerves; emitting a stimulus pulse from a probe or surgical tool; detecting neuro-muscular responses to the stimulus pulse in each of the plurality of spinal nerves; and concluding that the electrode disposed on the distal end of the at least one probe is positioned adjacent to a first spinal nerve when the neuro-muscular response detected in the first spinal nerve is detected as a current intensity level less than or equal to a corresponding neuro-muscular response onset value of the first spinal nerve.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS [0001] The present application claims priority under 35 U.S.C. § 120 from the commonly owned and co-pending U.S. patent application Ser. No. 09 / 722,070 filed Nov. 24, 2000, the complete disclosure of which is hereby incorporated herein by reference in its entirety for all purposes. Additionally, the present application claims benefit under 35 U.S.C. § 119(e) from U.S. Provisional Application Ser. No. 60 / 167,416 filed Nov. 24, 1999, the entire contents of which are hereby expressly incorporated by reference into this disclosure as if set forth fully herein.TECHNICAL FIELD [0002] The present invention relates to electromyography (EMG) and to systems for detecting the presence of nerves during surgical procedures. BACKGROUND OF THE INVENTION [0003] It is important to avoid unintentionally contacting a patient's nerves when performing surgical procedures, especially when using surgical tools and procedures that involve cutting or boring through t...

AI Technical Summary

Benefits of technology

Enables precise detection and monitoring of nerve proximity, reducing the risk of nerve damage by providing timely warnings and adapting to changes in nerve sensitivity during surgery, thus enhancing safety and accuracy in minimally invasive procedures.

Problems solved by technology

However, avoiding inadvertent contact with these nerves is especially difficult due to the high nerve density in the region of the spine and cauda equina.

Unfortunately, a downside of such minimally invasive surgical procedures is that they tend to offer a somewhat reduced visibility of the patient's tissues during the surgery.

Accordingly, the danger of inadvertently contacting and / or severing a patient's nerves can be increased.

However, such systems cannot be used when initially penetrating into the tissue.

Moreover, such optical viewing systems cannot reliably be used to detect the location of small diameter peripheral nerves.

A disadvantage of such systems is that they rely on a visual indication, being seen as a “twitch” in the patient's body.

During precision minimally invasive surgery, uncontrollable patient movement caused by patient twitching, is not at all desirable, since such movement may itself be injurious.

Accordingly, such systems are quite limited, and are not particularly well adapted for use in minimally invasive surgery.

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