User Documentation

Acquire Mode

Connection, calibration, monitoring, and recording workflows.

Acquire mode is the workspace for live interaction with the Vimotis system. Use this mode when hardware is connected and you are preparing, monitoring, or recording an acquisition session.

Acquire mode supports:

  • connecting or reconnecting to the data-acquisition hardware,
  • reviewing acquisition, processing, and calibration settings,
  • viewing live tensiometer, analog-input, and accelerometer plots,
  • selecting the save folder and run file name, and
  • recording data to disk.

When Acquire mode is active, these uniqe acquire mode menu actions are available:

  • File > Reconnect: attempt to reconnect to the DAQ or Vimotis unit.
  • Edit > Calibration: open the Calibration window.

Calibration Dialog

The Calibration dialog is used to review or update per-tensiometer calibration settings.

Figure 1: Calibration dialog for reviewing sensor calibration points and fitted conversion values.
Figure 1: Calibration dialog for reviewing sensor calibration points and fitted conversion values.
Setting Description
Start Calibration / Stop Calibration Starts or stops tapping while collecting calibration points.
Calibration Mode Switches between Point-based calibration and Slope + Zero-load WS calibration.

Point-based: computes inverse statics for two reference points of known load and wave speed. Applies a linear regression to the wave-speed-squared vs. load relationship.

Slope + Zero-load WS: directly defines a slope ([load] / [wave speed]) and zero-load intercept.
Tensiometer tabs Select the tensiometer being calibrated.
Tendon MA Moment arm of the tendon of interest for the selected tensiometer.
External MA Moment arm of the externally applied calibration force for the selected tensiometer.
Contr. to Net Torque [%] Percent contribution to the total physiological joint torque by the muscle-tendon group for the selected tensiometer.
Point-based calibration
Wave Speed [m/s] Calibration-point wave speed value.
Ext. Force External force value for the calibration point, shown in the active force unit.
Slope + Zero-load WS calibration
Slope Fitted or entered calibration slope.
Zero-load WS [m/s] Zero-load wave speed for slope-based calibration.
Time Offset [ms] Timing offset applied to the selected tensiometer.

While the sensor is active ("Play" button from main window or Start Calibration button), use the Set buttons to acquire the wave speed for each calibration point. For example, a simple Achilles tendon calibration would involve taking a "slack" tendon measurement (muscle-tendon unloaded), and clicking Set for Cal. Point 1, then repeating for a static known-load case for Cal. Point 2.

Toolbar and Run Controls

Figure 2: Acquire workspace with sensor plots, recording controls, save-path controls, and status indicators.
Figure 2: Acquire workspace with sensor plots, recording controls, save-path controls, and status indicators.

The Acquire toolbar includes the core session controls:

  1. Start or pause tap control,
  2. Save-path selection,
  3. Editable save folder field,
  4. File-name field,
  5. Collection duration field in seconds,
  6. Start or stop collection control, and
  7. Arm/disarm trigger with selectable rising-edge () or falling-edge () behavior. The trigger level is nominally 5V and occurs on the transition between states.

Channel Select

Figure 3: Channel selection and settings.
Figure 3: Channel selection and settings.

The left-side channel control area is used to choose which channels are visible and which signal is shown in the main plot target.

  1. The check boxes by each channel (tensiometer and analog) are used to enable/disable that channel.
  2. Each channel may be individually labeled to indicate the tendon or signal being measured. If no label is set, the defaults are T1-T4, and AI1-AI2
  3. The Calibrate button launches the calibration dialog (see Calibration Dialog)
  4. The system has two analog inputs (±10V) which are sampled at 50kS/s synchronously with the tensiometers. To match sample rate between tensiometers and AI channels, decimate the AI channels by 5k.
  5. An optional threshold marker may be enabled as a visual reference or for biofeedback. This draws a horizontal line on the wave speed / load plot at the specified y-axis location.

Plots and Plot Interactions

Acquire mode provides multiple live plot areas:

  • Tensiometers: main wave-speed or calibrated-load display,
  • Analog Channels: analog input plots,
  • Accelerometers: per-sensor accelerometer views.
Figure 4: Plot views (left to right): Tensiometers, Analog Channels, Accelerometers.
Figure 4: Plot views (left to right): Tensiometers, Analog Channels, Accelerometers.
  1. Switch between plotting wave speed and calibrated load data using this dropdown.
  2. Select an active tensiometer channel from one of these dropdowns to view its raw signals.

Plot Interactions

  • Plot items can be hidden/revealed by clicking on the legend entry to toggle visibility.
  • The x- and y-axis zoom is controlled by clicking and dragging in the direction and over the region of interest. Double-click to reset the axes.

Status Messages

The status area reports operating state, connection messages, recording status, and errors, and is located in the bottom left corner of the application.

Normal Output

The current implementation writes acquisition output to an HDF5 file with an .h5 extension. All data captured live as well as post-processed data are contained within this .h5 file.

Static local documentation generated from web_docs/src. Open index.html directly or host the site folder later.