Surgery – Diagnostic testing – Sensitivity to electric stimulus
Reexamination Certificate
2000-04-06
2001-11-06
Winakur, Eric F. (Department: 3736)
Surgery
Diagnostic testing
Sensitivity to electric stimulus
C600S587000, C607S048000
Reexamination Certificate
active
06312392
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to nerve locators and evaluators. More specifically, the present invention relates to a bipolar nerve locator and evaluator. Still more specifically, the present invention relates to a bipolar nerve locator and evaluator that includes a pressurized gas source for removing blood and fluid from the operative field as well as between the electrical leads and further which includes a fiber optic light source.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 4,962,766 discloses a nerve locator and evaluator which is used in surgical procedures. An AC energizing current is transmitted through an electrical lead to the patient. High and low settings are available and the device is equipped with an auditory signal to alert the surgeon when current is flowing through the patient's body.
However, despite the progress provided by the device disclosed in U.S. Pat. No. 4,962,766, the device has been found to be unsatisfactory for a number of reasons. First, the device is mono-polar and is equipped with a single electrode at the evaluation tip. As a result, the device requires a secondary ground wire that exits the back end of the handpiece. The ground wire attaches the patient's body with a conductive patch or needle electrode. This arrangement is problematic because the needle can fall out or the patch can peel off during the procedure. Further, the ground wire can extend across the surgical area and become entangled with other instruments during the surgical procedure. Consequently, the ground wire can become dislodged and the device temporarily inoperable during surgery. As a result, there is a need for an improved nerve locator and evaluator which does not require the employment of a ground wire or lead.
Still further, the tip of the device disclosed in U.S. Pat. No. 4,962,766 is applied directly to the patient. Because it is employed during a surgical procedure, excessive amounts of blood and fluid are typically present. The blood and fluid makes it difficult for the surgeon to see the exact area where the distal tip of the device is being applied. Consequently, it can be difficult for the surgeon to make visual contact with the nerve that is being located or stimulated because of the presence of the blood and fluid. In addition to enhancing the surgeon's visualization of the nerve under investigation, removal of blood and fluid would also be important to electrically isolate the nerve prior to location or evaluation and further to prevent any electrical shunting of current applied to the nerve. As a result, there is a need for an improved nerve locator and evaluator which has a built-in mechanism for removing excess blood and fluid from an area under observation or investigation.
Similarly, the device disclosed in U.S. Pat. No. 4,962,766 is not equipped with any sort of a light source to assist the surgeon in viewing the distal end of the instrument tip. As a result, there is a need for an improved nerve locator and evaluator that is equipped with a built-in illumination means.
Finally, while the device disclosed in U.S. Pat. No. 4,962,766 has high and low current settings, the device does not incorporate preset evaluation parameters which allow for locating and evaluation. As a result, there is a need for an improved nerve locator and evaluator with predetermined settings for frequency, evaluation pulse duration and amplitude for the separate operations of nerve evaluation and nerve location.
SUMMARY OF THE INVENTION
The present invention satisfies the aforenoted needs by providing a hand-held combination surgical nerve evaluator and locator that does not require a separate ground lead or connector. The device of the present invention is a bipolar device and utilizes two electrical leads in the probe, one of which serves as a return or a ground lead. In an embodiment, the hand-held combination surgical nerve evaluator and locator of the present invention also includes a pressurized gas source for clearing blood and fluids away from the area between the distal tips of the two electrical leads as well as the operative field. In an embodiment, the surgical nerve evaluator and locator of the present invention also includes a built-in light source in the form of a fiber optic light guide. Still further, in an embodiment, the surgical nerve evaluator and locator of the present invention also includes two predetermined settings, one for nerve location and one for nerve evaluation.
In an embodiment, the present invention provides a hand-held combination surgical nerve evaluator and locator that comprises a handpiece that comprises a housing that accommodates a circuit board connected to a DC voltage source. The circuit board also comprises a pulsed current source. The pulsed current source is connected to a first electrical lead. The housing is also connected to a second electrical lead. The first and second electrical leads extend outward from one end of the housing in a parallel and spaced-apart fashion.
The circuit board and pulsed current source are connected to a nerve evaluation switch and a nerve location switch. Movement of the nerve evaluation switch to an activation position causes a first pulsed current to be generated by the pulsed current source and transmitted to the first electrical lead. The first pulsed current has a nerve evaluation frequency, a nerve evaluation pulse duration and a nerve evaluation amplitude.
In contrast, movement of the nerve location switch to an activation position causes a second pulsed current to be generated by the pulsed current source and transmitted to the first electrical lead. The second pulsed current has a nerve location frequency, a nerve location pulse duration and a nerve location amplitude.
The nerve evaluation frequency is less than the nerve location frequency. The nerve evaluation pulse duration is less than the nerve location pulse duration. The nerve evaluation amplitude is less than the nerve location amplitude.
In accordance with the present invention, the second electrical lead serves as a return electrical lead or a ground.
In an embodiment, the nerve location frequency ranges from about 5 to about 9 Hz.
In an embodiment, the nerve pulse duration ranges from about 300 to about 700 &mgr;sec.
In an embodiment, the nerve location amplitude ranges from about 700 to about 1100 ma.
In an embodiment, the nerve evaluation frequency ranges from about 1 to about 3 Hz.
In an embodiment, the nerve evaluation pulse duration ranges from about 150 to less than 300 &mgr;sec.
In an embodiment, the nerve evaluation amplitude ranges from about 150 to about 250 ma.
In an embodiment, the nerve location frequency is about 7 Hz; the nerve location pulse duration is about 500 &mgr;sec; the nerve location amplitude is about 900 ma; the nerve evaluation frequency is about 2 Hz; the nerve evaluation pulse duration is about 250 &mgr;sec; and the nerve evaluation amplitude is about 200 ma.
In an embodiment, the device of the present invention further comprises a compressed gas source located within the housing and that is connected to the circuit board. The device further comprises a cannula connected to the compressed gas source. The cannula, the first electrical lead and the second electrical lead all comprise distal ends. The cannula extends outward from the end of the housing and between the first and second electrical leads. Movement of either the nerve location switch or the nerve evaluation switch to an activated position causes the compressed gas source to communicate pressurized gas through the cannula and between the distal ends of the first and second electrical leads.
In an embodiment, the compressed gas source is a pump.
In an embodiment, the pump is selected from the group consisting of a solenoid pump, a diaphragm pump, a rotary pump and a vane pump.
In an embodiment, the compressed gas source is a canister of compressed or liquid carbon dioxide.
In an embodiment, the compressed gas source is a canister of compressed or liquid air.
In an embodiment, the compressed gas sour
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Winakur Eric F.
Wingood Pamela
LandOfFree
Bipolar handheld nerve locator and evaluator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bipolar handheld nerve locator and evaluator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bipolar handheld nerve locator and evaluator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2607018