MyoTrac 4000 User Guide

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Type BF Equipment

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Internally powered equipment

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Continuous operation

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Read Instruction

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US Federal Law restricts this device to sale by or on order of licensed health care practitioners.

CAUTION

WARNING

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Do not operate MyoScan sensor within 10 feet of an operating cellular phone, similar radio transmitting device, other powerful radio interference producing sources such as arc welders, radio thermal treatment equipment, x-ray machines or any other equipment that produces electrical sparks etc.

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Do not connect inputs or outputs of the encoder or sensors to line powered devices.

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All MyoTrac units are totally isolated from line (110 or 220VAC) power due to battery operation. However, many hospitals and the FDA require that computers, printers and any other equipment used with medical devices be electrically isolated from line voltage to UL or CSA medical safety standards.

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After use, the Disposable Electrodes may be a potential biohazard. Handle, and when applicable, dispose of these materials in accordance with accepted medical practice and any applicable local, state and federal laws and regulations.

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Radiated radio frequency electromagnetic fields can cause performance degradation in the MyoScan sensor. In the worst case, a RF field strength of 22mV/M can cause a degradation of 1μV in the signal from the MyoScan sensor. Be sure to keep in mind that a very relaxed muscle should provide an EMG reading of approximately 1-3μV.

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Do not use in the presence of a flammable anesthetic mixture with air or with Oxygen or Nitrous Oxide.

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Not to be immersed in water.

ATTENTION •

To prevent static discharge from damaging the sensor and/or encoders, use anti-static mats or sprays in your working area. A humidifier may also be used to prevent static environments by conditioning hot, dry air.

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To prevent voiding warranty by breaking connector pins, carefully align white guiding dot on sensor plug with slot on sensor input.

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Do not apply any electrode gel or equivalent directly on the sensor snaps. Always use electrodes as a medium between the sensor and the client.

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Make sure to remove electrodes from sensor snaps immediately after use.

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Apply conductive gel only to electrodes; never put gel directly to sensor snaps.

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Do not plug third party sensors directly into instrument inputs. Plug only Thought Technology Active Sensor cable connectors into instrument inputs. All EMG electrodes and third party sensors must be connected to MyoScan sensors, either directly or through an adapter.

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Remove batteries when the device is not being used for extended period of time. Please dispose of battery following national regulations.

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Sensors damaged by static electricity are not covered under warranty! In dry climates, apply anti-static spray on carpets each week and/or use a conductive floor mat (available from computer stores).

CONTRAINDICATIONS •

None

INTENDED PURPOSE •

Biofeedback, Relaxation & Muscle Re-Education purposes.

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No preventative inspections required. Maintenance must be performed by qualified personnel.

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The supplier will make available, upon request, circuit diagrams, component parts lists and description or other information required for the repair of product by qualified personnel.

NOTE

Manual # SA9601 Rev.5

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Model #: MyoTrac (4000P 60Hz ) Model #: MyoTrac (4001P 50Hz ) Table of Contents Introduction... 6 Installing and Testing Your Battery ... 7 Trying Your MyoTrac for the First Time ... 9 Use of the MyoScan™ Sensor ... 9 Front Panel Controls ... 14 Battery Compartment Controls... 15 Side Panel Jacks... 18 Setting the Threshold Potentiometer... 18 Connecting to a Voltage Monitoring Device ... 20 Care of Your Instrument ... 21 Specifications ... 22 Accessories ... 23 Warranty ... 24 Extended Warranty Program... 26 Repair Return Form... 28 Other Products and Services from Thought T... 29

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Introduction Biofeedback is a rapidly developing scientific field that has grown out of advances in physiology, psychology and electronics. Ordinarily, we are unaware of the subtle internal body activities that are part of our everyday lives. Biofeedback uses sensitive electronics to detect and amplify theses activities in order to bring them to awareness. By allowing us to observe these activities, biofeedback also allows us to learn to modify them. Since we are immediately aware of the outcome of our attempts, we can gradually learn to produce the results we desire. Muscles go through a wide range of activity. Normally, we are only aware of the muscle activity associated with movement, such as occurs in swinging a tennis racket. Yet much muscle activity produces no visible movement and, as a result, goes unnoticed. EMG (electromyographic) activity is a measure of the electrical activity in the muscles. Since the electrical activity of the muscle increases when the muscle is tensed and decreases when it is relaxed, EMG biofeedback can provide information about the state of relaxation or tension of our muscles. Our muscles respond to threatening, stressful situations with large increases in tension. This response is part of an old reflex left over from a time when one had to either fight or flee from a stressful situation in order to survive. Today, fighting or running isn't generally appropriate. So, in most stressful situations, there is increased muscle tension, which cannot be dissipated by fighting or fleeing. If this high tension continues, muscle fatigue, soreness, or even pain may result. Work with EMG and relaxation and tension began during ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ 6 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

the 1920's and 1930's through the pioneering efforts of Edmund Jacobson. Jacobson found that the more relaxed a muscle was, the lower its EMG activity level was. He also noted that this lowered EMG activity level was associated with a more general subjective sense of relaxation. EMG biofeedback is also being applied very successfully in rehabilitation medicine - such as in regaining control of lost muscle function, re-establishing the correct relationship between agonist and antagonist muscles, relaxing spasmodic activity and in strengthening weak or atrophied muscles. While Jacobson's work marked a milestone in EMG research, his methods of measuring EMG were crude and cumbersome by today's standards. The MyoTrac represents a tremendous step forward in EMG technology. Thanks to solid state electronics and micro circuitry, equipment which used to fill a laboratory in Jacobson's time can be replaced today by the MyoTrac - small enough to fit in the palm of your hand.

Installing and Testing Your Battery Battery Insertion: We strongly recommend the use of an alkaline or lithium 9 volt battery. You can use a rechargeable nickel-cadmium (NiCad) battery, but keep in mind that although NiCad batteries can be charged many times, they last only about one quarter as long in operation as an alkaline battery. To insert or remove the battery, hold the device in one hand and firmly grasp the sides of the battery compartment lid with the other. Pull straight towards the rear of the case to slide it off (see Figure 1). Replace the battery, being careful to observe the proper polarity. Slide the lid back in place, ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ 7 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

pushing gently to snap the clip.

Fig. 1 Opening the battery compartment

Note: Remove old batteries promptly to prevent corrosion. Remove the battery if the device is not going to be used for periods longer than one month. Testing the Battery: To check the battery, turn the unit on, place the threshold potentiometer to 5, and the scale-reading switch to x1. With a Triode electrode snapped on the MyoScan sensor, place the sensor over a muscle and tense it. If the first yellow LED in the middle of the bargraph does not light as the LEDs go from left to right, then change or recharge the battery.

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MyoTrac (SA4000P & SA4001P)

Trying Your MyoTrac for the First Time Plug the MyoScan sensor into the INPUT jack. Set the switches inside the battery compartment to: OFF, OFF, ABV, NAR (fig. 7). Set the gain switch to the x1 position. Turn the volume up. Set the threshold potentiometer to 10. (fig. 6). Snap a Triode electrode on the three MyoScan connectors (fig. 2). Hold the MyoScan sensor on your cheek with a light pressure, placing it just below the cheekbone (over the temporomandibular joint). Make certain that all three electrodes contact the skin. Observe the tone and bargraph reading as you tense and relax your jaw by clenching your teeth. When the first yellow LED lights up, the actual EMG reading corresponds to the threshold value that is set on the THR. Dial, in this case, 10μV.

Use of the MyoScan™ Sensor The MyoScan sensor incorporates sensitive electronic circuitry to amplify the minute EMG signals directly under the electrode connectors so that the MyoTrac's readings will not be affected by cable movement or outside electrical interference. For the MyoScan sensor to function properly, electrodes must be inserted on the sensor head. There are several choices of electrodes which can be used, depending ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ 9 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

on the muscle site to be monitored. The disposable Triode electrodes will be adequate for most applications. Disposable Triode Electrodes (#T3402M): Disposable electrodes avoid cross contamination of patients. The foambacked triangular Ag-AgCl (silver-silver chloride) Triode electrodes can be used for scanning most muscle sites for activity. Remove the back covering exposing the adhesive to firmly hold the MyoScan sensor in place (see figure 2). Generally, no skin surface preparation is required; however, for guaranteed stability over very dry or hairy areas, clean the target site with an alcohol wipe or apply a tiny dab of electrode gel to each electrode. Be careful to avoid applying the electrode gel to the skin between electrodes, which could attenuate the signals.

Fig. 2 Triode, single and Uni-Gel electrodes

For measuring EMG activity over specific muscle sites which are not suitably monitored by the triangular configuration, or where a wide placement is required, an extender cable can be used. Extender Cable (#T8720M): Thought Technology's 450mm extender cable can be inserted directly into the sensor head (figure 3), being careful to align the alignment ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ 10 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

dot on the cable connector with the groove on the sensor head. Sensor Head

Electrode Buttons

Tho u ght Tec h nolo gy L t d.

Align the groove with the dot Fig. 3 Extender Cable

When an extender cable is used, Disposable Single Electrodes (#T3404) or Disposable Uni-Gel Electrodes (#T3425) are snapped in the three electrode buttons (see figure 2 & 3). Note: To remove the electrodes, hold the sensor or the extender cable button with one hand, place the index finger of the other hand on the electrode and slide the thumb nail between the electrode and the electrode snap, pry the electrode gently out of the snap. Sensor placement: Generally, the sensor is placed on a muscle site so the two active electrodes are positioned parallel to the muscle fibers (i.e. placed in line with them). (See figure 4)

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Active electrodes

Reference electrode

Active electrodes

Muscle fibers Fig. 4 Sensor Placement

Sensor jacks and plugs: Plugs and jacks with protected pins: Thought Technology has developed its own patented gold plated protected pin system for all sensor and encoder plugs and jacks. The protected pins are designed to prevent any possibility of direct skin contact with the metallic elements that conduct the amplified signals. They also help prevent accidental damage from attempting to plug Thought Technology sensors and encoders to equipment for which they were not designed.

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Replacement Sensor Cable (Model T9385M) Thought Technology sensors use a highly flexible and lightweight cable. If, for any reason, a break should occur in the cable, a replacement cable is available. To change cables, tightly grip the connector plugged into the sensor with your index finger and thumb and pull out the cable from the sensor. Replace the cable with a new one, being careful to align the plug with the appropriate holes in the sensor jack (plug will align only in one direction).

Model #SA9385M To change cables, tightly grip the connector plugged into the MyoScan with your thumb and index, and pull gently on the connector. Replace the cable with a new one. Be very careful to align the notch on the cable connector with the guiding groove on the sensor head, since the plug will align in only one direction (see figure 5).

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Guiding Notch and Groove

Fig. 5 Cable Connectors

Front Panel Controls The front panel (see figure 6) includes controls for sound level (VOLUME), threshold level (THR), three gain settings, x1, x10 and x100 for ranges of .08-20, .08-200 and .08-2000 microvolt (μV). R.M.S., respectively. Also, a power switch lets you select OFF and either continuous proportional tone feedback (CONT) or threshold feedback (THR). Threshold feedback allows you to set control parameters for the tone feedback to be enabled or disabled when the EMG signal exceeds or falls below the threshold setting of the threshold control. The various threshold functions are chosen from the switch settings in the battery compartment.

Power & Feedback

Green

Gain

Threshold

Yellow

MyoTrac (SA4000P & SA4001P) Fig. 6 Front Panel

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Note: Previous models of the MyoTrac EMG unit had only one yellow LED and five red ones on the right. In those units, the yellow LED corresponds to the set threshold value.

Battery Compartment Controls Within the battery compartment are switches to set a variety of choices as follows: (see figure 7) WIDE/NAR bandpass (20-500 Hz. or 100-200 Hz.): Sets the frequency range for signal detection. The 20-500 HZ. range detects a wider range of EMG signals, but is also prone to cardiac (EKG) interference. For this reason, it is not recommended for monitoring sites on the back or torso. ABV/BLW: This switch determines if the tone feedback is turned on when the signal exceeds (ABV) or falls below (BLW) the threshold potentiometer setting. ALARM/OFF: When either the 4 or 60 second switch is set, the threshold is exceeded for at least 4 or 60 seconds, a continuous (not proportional) tone will sound. This alarm will sound as long as the signal stays above threshold. As soon as the signal drops below the threshold, the tone turns off. If the threshold is exceeded again for 4 or 60 consecutive seconds, the warning signal will start once more. Note: Alarm does not work with the BLW setting. LOCK/OFF: Works only with alarm (ALARM) on. LOCK locks on a continuous high-pitched tone to alert the user that the threshold level has been exceeded (if set ABV), ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ 15 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

for more than 4 or 60 seconds. Once the warning signal has been triggered on, it can only be canceled by moving the front panel power switch to the CONT or OFF positions.

ALARM (Sec.)

60

LOCK

ON

BLW WIDE

4

OFF

OFF

ABV

NAR

Fig. 7 Battery Compartment Controls

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The three threshold switches, LOCK/OFF, ALARM/OFF and BLW/ABV are only functional when the front panel power switch is set to THR. Possible combinations are: LOCK/OFF

ALARM/OFF

ABV/BL W

1

OFF

OFF

ABV

Proportional tone feedback above threshold.

2

OFF

OFF

BLW

Proportional tone feedback below threshold.

3

OFF

ALARM

ABV

Alerting tone when EMG above threshold for > 4 or 60 seconds. (goes off immediately when EMG goes below threshold).

4 or 60 sec. 4

OFF

ALARM

BLW

Not valid position. Alarm (ALARM) works only for above (ABV) threshold position.

5

LOCK

ALARM

ABV

Same as condition 3; however the tone locks on until the power switch (OFF/CONT/THR) is turned off.

6

LOCK

ALARM

BLW

Not a valid position.

7

LOCK

OFF

ABV

Not a valid position.

8

LOCK

OFF

BLW

Not a valid position.

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Side Panel Jacks (see figure 8) INPUT: Plug the MyoScan sensor in here. EAR: Plugging the earphones in here disconnects the internal speaker and sends tone feedback through the earphones. 0-2V: Provides a 0-2 Volts output signal. The MyoTrac can be connected to other third party device with an isolated voltage input that accepts 0-2V. Make certain the instrument complies with IEC 601-1. Note: This output is the same for all the gain settings. An output value of 2 Volts will represent 20 μV at the x1 setting, 200 μV at x10 and 2000 μV at x100.

, WARNING: Never connect your MyoTrac to an A.C. powered device! Setting the Threshold Potentiometer

The threshold control’s main function is to set a goal value for the EMG signal. When that value is reached, the tone is heard, which provides immediate feedback to reward or inhibit a particular behavior. This control can also be used to place the EMG signal at a desired point on the bargraph, moving it right or left by turning the knob. It is also possible to determine the exact EMG reading in micro Volts. As previously mentioned, when the signal is at the first yellow LED, EMG activity corresponds to the threshold setting. The left-most LED indicates 1/2 the threshold value and the right-most LED is 2 times the threshold value. ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ 18 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

The Gain setting determines the reading range: 0-20 μV at x1, 0-200 μV at x10 and 0-2000 μV at x100. For each gain setting, the possible threshold values are: .5-10 μV (x1), 5100 μV (x10), and 50-1000 μV (x100) respectively. Example of Threshold Setting: If you want to do a feedback session for the purpose of encouraging an increased level of activity in a specific muscle, initially set the gain to x1. If, with a normal contraction, the reading is near the left end of the green scale, then you might want to set the threshold control to a lower number (turn the knob clockwise); this will move the signal toward the right, making it easier to reach the threshold. Conversely, if the reading is at the top of the scale (all the way to the right), you might want to increase the threshold (turn the knob counterclockwise) to move the signal to the left. If this is not sufficient, you can increase the range by switching the scale reading switch to the x10 or x100 position. Let’s say that the THR dial is set to 5 and the gain switch to x10. The first yellow LED would represent 50 μV (5 x 10), the left most green LED would be 25 μV and the right most yellow LED, 100 μV.

MyoTrac (SA4000P & SA4001P)

25 V

50 V

100 V

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Connecting to a Voltage Monitoring Device Connect the 0-2V output jack (see figure 8) to any instrument capable of reading from 0-2 Volts (digital voltmeter, analog voltmeter, polygraph, integrator, etc.). Make certain the instrument is battery operated or complies with IEC 601-1. The output voltage will always be in the 0-2 Volt range; however, the actual EMG level in microvolt RMS is dependent upon the Gain setting. Range values are obtained by multiplying the output voltage reading as follows: Switch = x1, multiply by 10

Ex: Voltage = 0.9; EMG = 9 μV

Switch = x10, multiply by 100

Ex: Voltage = 1.5; EMG = 150 μV

Switch = x100, multiply by 1000

Ex: Voltage = 1.1; EMG = 1100 μV

Fig. 8 Side Panel Jacks

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