VARI-STIM® III Surgical Nerve Locator Instuctions for Use

English

English DEVICE DESCRIPTION The Vari-Stim® III Nerve Stimulator is a battery powered nerve locator with continuous output current adjustable to approximately 0.5mA, 1.0mA, and 2.0mA. A subcutaneous needle electrode (positive ground) is attached. The LED light is used to test the device. INTENDED USE / INDICATIONS FOR USE The device is intended for the stimulation of exposed motor nerves or muscle tissue to locate and identify nerves and to test nerve excitability. CONTRAINDICATIONS The device is not indicated for use when paralyzing anesthetic agents are being used as they will significantly reduce, if not completely eliminate, EMG responses to direct or passive neural stimulation. WARNINGS • Use 0.5 mA setting initially, this will help prevent over-stimulation of the nerve. • Limit nerve contact to 1 second maximum as indicated by the LED, as excessive pressure or prolonged locator contact with nerves may result in neural injury. • Due to variations in tissue impedance and, hence, current delivered, activation of the LED may not be always be achieved despite delivering current during surgery. Confirm functionality by touching the probe tip and needle electrode. • During surgery, a lit LED confirms delivery of current. If the LED is not activated intraoperatively, the device can be tested by touching the probe tip to the needle electrode. • This device is not designed to determine the degree of neural viability. • The device remains active whenever the needle electrode is in the patient. Do not leave the device unattended in the surgical field. • Do not use in the presence of any flammable material, there is a potential for ignition. • The device should not be used while a NIM™ EMG monitor is in use, as it will cause false positive responses. • Do not bend the probe tip as the device may become damaged and malfunction. • To ensure continued functionality, re-test after changing the current setting. • Excessive pressure or prolonged stimulator contact with the nerve could result in neural injury. • Improperly placed or bent needle electrodes, and attempts to straighten bent electrodes, increase the risk of the needle breaking off in the patient. • False negative responses (failure to locate the nerve) may result from neuromuscular fatigue from prolonged or repeated stimulation. • Contaminated single use electrodes and probes must be disposed of in an appropriate sharps container in accordance with user facilities policy. PRECAUTIONS • Medical Electrical Equipment needs special precautions regarding EMC and needs to be installed and put into service according to the EMC information provided in this Guide. • Portable and mobile RF communications equipment can affect Medical Electrical Equipment. • The Vari-Stim® III should not be used adjacent to or stacked with other equipment. If adjacent or stacked use is necessary, the Vari-Stim® III should be observed to verify normal operation in the configuration in which it will be used. INSTRUCTIONS FOR USE FUNCTIONALITY TEST: Touch the probe tip to the needle electrode. This will cause the LED light at the back of the housing to illuminate and verifies its functionality. The LED will turn off when the probe tip and needle electrode are separated. Do not attempt to use a unit that fails this test. SET-UP: Insert positive needle electrode anywhere into subcutaneous tissue. When probe contacts exposed tissue, the LED indicator at rear of the device will light. This assures that the circuit is completed through tissue. Muscle response occurs when the probe touches exposed nerve or muscle tissue. CURRENT ADJUSTMENT: Select output amperage by rotating the probe index until marker is aligned with desired output. The 0.5 mA setting should be used initially. If the normal innervated muscle does not respond, increase current setting as required. The amount of current used for nerve or muscle should be just enough to cause a response. The excitability of indirectly evoked muscle response by stimulation of corresponding motor nerve is substantially more sensitive than that of direct electrical muscle stimulation. RECOMMENDED STIMULATION TECHNIQUE: Use the Vari-Stim® III by gently touching the nerve for a brief moment, (less than 1 second) as indicated by the LED, and just long enough to see the normal instantaneous muscle response. Depending on stimulation technique, the probe contact period necessary should be approximately 0.1 s (second) and never more than 1 s (second). This device is not designed to determine the degree of viability of nerve or muscle. It is for identification of exposed motor nerves or muscle only. STERILITY The Vari-Stim® III is provided sterile and is intended for SINGLE PATIENT USE ONLY. DO NOT RESTERILIZE THIS PRODUCT. MEDTRONIC XOMED ASSUMES NO LIABILITY FOR PRODUCTS WHICH HAVE BEEN RESTERILIZED BY HEALTH CARE FACILITIES.

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Norsk Guidance and manufacturer’s declaration – electromagnetic immunity - Part 1 The Vari-Stim® III is intended for use in the electromagnetic environment specified below. The customer or the user of the Vari-Stim® III should assure that it is used in such an environment. Immunity test

EN 60601 test level

Compliance level

Electrostatic discharge (ESD) EN 61000-4-2

±6 kV contact

±6 kV contact

±8 kV air

±8 kV air

3 A/m

3 A/m

Power frequency (50/60 Hz) magnetic field EN 61000-4-8

Electromagnetic environment - guidance Floors should be wood, concrete, or ceramic tile. If floors are covered with synthetic material, the relative humidity should be at least 30 %. Power frequency magnetic fields should be at levels characteristic of a typical location in a typical commercial or hospital environment.

Guidance and manufact urer’s declaration – electromagnetic emissions The Vari-Stim® III is intended for use in the electromagnetic environment specified below. The customer or the user of the Vari-Stim® III should assure that it is used in such an environment. Emissions test

Compliance

Electromagnetic environment - guidance

RF emissions CISPR 11

Group 1

The Vari-Stim® III uses RF energy only for its internal function. Therefore, its RF emissions are very low and are not likely to cause any interference in nearby electronic equipment

RF emissions CISPR 11

Class B

Harmonic emissions EN 61000-3-2

N/A

Voltage fluctuations EN 61000-3-3

N/A

The Vari-Stim® III is suitable for use in all establishments, including domestic establishments and those directly connected to the public low-voltage power supply network that supplies buildings for domestic purpose.

Recommended separation distances between portable and mobile RF communications equipment and the Vari-Stim® III

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Norsk The Vari-Stim® III is intended for use in the electromagnetic environment in which radiated RF disturbances are controlled. The customer or the user of the Vari-Stim® III can help prevent electromagnetic interference by maintaining a minimum distance between portable and mobile RF communications equipment (transmitters) and the Vari-Stim® III as recommended below, according to the maximum output power of the communications equipment. Rated maximum power of transmitter W

Separation distance according to frequency of transmitter (meters) 150 kHz to 80 MHz

80 MHz to 800 MHz

800 MHz to 2.5 GHz

d = 1.2√P

d = 1.2√P

d = 2.3√P

0.01

0.12

0.12

0.23

0.1

0.38

0.38

0.73

1

1.2

1.2

2.3

10

3.8

3.8

7.3

100

12

12

23

For transmitters rated at a maximum output power not listed above, the recommended separation distance d in meters (m) can be estimated using the equation applicable to the frequency of the transmitter, where P is the maximum output power rating of the transmitter in watts (W) according to the transmitter manufacturer. NOTE 1: At 80 MHz and 800 MHz, the separation distance for the higher frequency range applies. NOTE 2: These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and reflection from structures, objects and people.

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Norsk

Guidance and manufacturer’s declaration – electromagnetic immunity - Part II The Vari-Stim® III is intended for use in the electromagnetic environment specified below. The customer or the user of the Vari-Stim® III should assure that it is used in such an environment. Immunity test

EN 60601 test level

Compliance level

Electromagnetic environment - guidance Portable and mobile RF communications equipment should be used no closer to any part of the Vari-Stim® III, including cables, than the recommended separation distance calculated from the equation applicable to the frequency of the transmitter. Recommended separation distance

Conducted RF EN 61000-4-6

Radiated RF EN 61000-4-3

3 Vrms 150 kHz to 80 MHz

3 V/m 80 MHz to 2.5 GHz

N/A

d = 1.2√P

d = 1.2√P 80 MHz to 800 MHz 3 V/m

d = 2.3√P 800 MHz to 2.5 GHz

where P is the maximum output power rating of the transmitter in watts (W) according to the transmitter manufacturer and d is the recommended separation distance in meters (m). Field strengths from fixed RF transmitters, as determined by an electromagnetic site survey, (a) should be less than the compliance level in each frequency range. (b) Interference may occur in the vicinity of equipment marked with the following symbol

NOTE 1: At 80 MHz and 800 MHz, the higher frequency range applies. NOTE 2: These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and reflection from structures, objects and people.

(a): Field strengths from fixed transmitters, such as base stations for radio (cellular/ cordless) telephones and land mobile radios, amateur radio, AM and FM radio broadcast and TV broadcast cannot be predicted theoretically with accuracy. To assess the electromagnetic environment due to fixed RF transmitters, an electromagnetic site survey should be considered. If the measured field strength in the location in which the Vari-Stim® III is used exceeds the applicable RF compliance level above, the Vari-Stim® III should be observed to verify normal operation. If abnormal performance is observed, additional measures may be necessary, such as re-orienting or relocating the Vari-Stim® III. (b): Over the frequency range 150 kHz to 80 MHz, field strengths should be less than 3 V/m.

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0123 © Medtronic 10/2009 68E3926 B

Manufactured by: Medtronic Xomed, Inc. 6743 Southpoint Drive North Jacksonville, FL 32216 U.S.A. www.medtronicENT.com EC Authorized Representative: Medtronic B.V. Earl Bakkenstraat 10 6422 PJ Heerlen The Netherlands