Electromyographic Assessment of the TetraGraph in Normal Volunteers

Study Overview
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Brief Summary
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There is an urgent need for an easy-to-use and accurate quantitative neuromuscular monitor in the clinical setting. The aim of this clinical investigation is to examine a prototype of a quantitative monitoring instrument that will meet most, if not all, of the clinical requirements.

Official Title
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Electromyographic Assessment of the TetraGraph in Normal Volunteers

Conditions
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Neuromuscular Blockade

Intervention / Treatment
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* Device: TetraGraph
* Device: TOF Watch


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria Age 18 years or older Volunteer meets the American Society of Anesthesiology (ASA) physical status I-III criteria Volunteer has provided verbal informed consent Exclusion Criteria Presence of an underlying neuromuscular disease Use of medications known to interfere with neuromuscular transmission Volunteer has open sores/rashes at the locations needed for electrode application Volunteer does not tolerate a trial electrical stimulation comfortably.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: TetraGraph|A sequence of 3 sets of Train of four (TOF) stimuli delivered (every 20 sec) at the pre-determined current amplitude (for instance, 40 mA, then 30 mA, then 50 mA, then 20 mA).|
|Device: TOF Watch|A sequence of 3 sets of TOF stimuli delivered (every 20 sec) at the pre-determined current amplitude (for instance, 40 mA, then 30 mA, then 50 mA, then 20 mA).|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of train of four measurements between TOF Watch and TetraGraph | The primary endpoint will be an analysis of the agreement between the TOF-Watch (the current gold standard) and TetraGraphTM devices during neuromuscular monitoring. Data Acceleromyography (AMG) and Electromyography (EMG) will be compared between the two devices during testing of single twitch (ST) and train of four (TOF) patterns at varying current amplitudes, from threshold amplitude (the lowest current amplitude that is able to generate a muscle response), to supramaximal current amplitude (the amplitude that elicits maximal muscle response). Bias and limits of agreement will be calculated for each stimulation pattern (ST and TOF) at currents between submaximal and supramaximal amplitude. Measured responses obtained with the two technologies (AMG and EMG) will be compared. | During stimulation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Noise level | Acceptable levels of electrical noise when no stimulus is being applied (random noise, power-line noise, and background EMG recorded in a relaxed volunteer with low recording electrode impedance should be 0.2 mV RMS or less). | During stimulation | 
| Stimulus artifact | That the stimulus artifact will not obscure the EMG response when a stimulus is applied. | During stimulation | 
| Appearance EMG response | Appearance of an EMG response at threshold stimulation levels, enough to just barely elicit a visible twitch response and elicit measurable acceleration on the TOF-Watch. | During stimulation | 
| EMG amplitude | Increase in the amplitude of the EMG response, with constant response latency, corresponding to the increase in the AMG response as stimulus strength (current) is increased. | During stimulation | 
| Maximal EMG amplitude | The observation of a maximal EMG amplitude, corresponding to the maximal AMG response, at maximal and supramaximal (up to maximal+10%, but below 70 mA) stimulus levels. | During stimulation | 
| Consistency in amplitude | Consistency in the amplitude of the AMG and EMG response amplitudes, with measured variations less than 10%, on repeated 1 Hz stimulation when the stimulus current is held constant between threshold and supramaximal intensity. Consistency of the AMG and EMG response amplitudes in repeated (ST and TOF) stimulus protocols (in which variation should be less than 10%). Consistency of EMG response characteristics and association with AMG responses independent of patient age, gender, or weight (despite different stimulus amplitudes being required to elicit submaximal and supramaximal responses). Consistency of EMG response characteristics and association with AMG responses independent of whether the right or left arm is being stimulated. | During stimulation | 
| Discomfort level | Establish the discomfort associated with nerve stimulation (from submaximal to supramaximal current amplitudes) in awake, unpremedicated human volunteers. Assessment will be made using an 11-point visual analog score (VAS) scale, anchored with 0 = no distress and 10 = worst distress ever experienced | During stimulation |