Trigno Discover: MVC Calibration

Overview

This guide walks you through performing an MVC (Maximum Voluntary Contraction) calibration in Trigno Discover to normalize EMG signals and express muscle activity as a percentage of maximum effort. You’ll learn how to access and configure the calibration interface, define contraction protocols, and run a guided sequence of muscle contractions. The guide also covers applying calibrations to sensors and viewing real-time EMG output as a percentage of MVC. This process ensures accurate, repeatable data comparison across sessions and subjects, and between muscles. Auxiliary sensors can be calibrated using either the manual or collected options within the Calibration module of Trigno Discover. However, this article will specifically walk through the MVC calibration process. For a visual walkthrough, please refer to the Trigno Discover video tutorials on MVC Calibration.

Information

• This article refers to Trigno Discover version 2.0.1. Please note that the user interface may vary depending on the version you have installed. You can find your current version of Trigno Discover in the top left corner of the application window.

Trigno Discover Getting Started Video Tutorial: MVC Calibration

System Requirements

Step-by-Step Instructions

Step 1: Accessing Calibration Settings

1. Open the Sensor Settings Panel

   1. Navigate to the Sensor Settings Icon of the sensor you wish to calibrate.

   2. Calibration only applies to:

      1. The selected sensor

      2. The current configuration mode selected

Information

• Calibrations are sensor-specific. Switching sensors or modes requires a new calibration.

Step 2: Starting an MVC Calibration

1. Launch the Calibration Window

   1. Click “Calibrate” to open the Sensor Calibration panel.

2. Choose MVC Calibration

   1. Select MVC Calibration from the options.

   2. Click “Begin”.

   3. Rename the calibration (optional), then click “Save”.

Step 3: Configuring Calibration Parameters

1. Access Calibration Settings Icon

   1. Click the Calibration Settings icon in the top-right.

2. Customize Calibration Settings

   1. Set:

      • Number of contractions (minimum 2)

      • Contraction and rest durations

      • Instructional text shown during calibration

3. Click “Save” to confirm.

Step 4: Optional – Multi-Channel Calibration

1. Enable Multi-Channel Mode (For Multi-Headed Sensor)

   1. In the lower-right of the calibration window, enable “Configure All Channels.”

   2. This will calibrate all EMG channels on the selected multi-headed sensor.

Step 5: Performing the Calibration Trial

1. Start the Calibration

   1. Select “Start Collection” to begin the calibration process.

2. Follow the Instructions on the Screen

   1. The system will alternate between:

      1. “Contract” – exert maximum voluntary effort

      2. “Rest” – fully relax the muscle

3. Complete the sequence as instructed on-screen.

Information

• Calibrations can only be performed on a single sensor at a time.

Recommendation

• Ensure participants give maximum effort during each contraction for reliable results. Participants should aim to relax their muscle completely during the “rest” period to ensure an accurate baseline measurement.

Step 6: Saving or Repeating Calibration

1. Save the Calibration

   1. Once the trial completes, click “Save Calibration.”

2. Recalibrate if Necessary

   1. If data quality is poor or effort was submaximal:

   2. Click “Recalibrate” to repeat the process.

Step 7: Applying the Calibration

1. Saving the Calibration

   1. Select the “Save” option

      1. This will automatically apply the calibration

      2. The calibration name will appear under the trial settings configuration pane.

2. Selecting Other Calibrations

   1. In order to select other calibrations, open the Sensor Configurations Menu.

   2. Use the calibration drop-down menu to choose your saved calibration.

   3. Click “Apply & Close” to confirm.

3. Viewing Calibrated Data in Real Time

   1. During a live stream, calibrated EMG values will be shown as a percentage of the MVC.

Information

• Calibrating the sensor will allow for the data to be visualized using the biofeedback tools. (See Trigno Discover: Biofeedback Displays)

For more information on Trigno Discover, please refer to the next article in the Trigno Discover Getting Started Series: Trigno Discover: Data Collection & Review.

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