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Bilateral Stimulation (EMDR)

The Bilateral Stimulation (BLS) tool is a real-time stimulus tool designed specifically for EMDR (Eye Movement Desensitization and Reprocessing) therapy. It enables therapists to provide visual bilateral stimulus, alternating left and right tones, or both at once to patients, whether they are in the same room or connecting remotely.

What you can do

  • Create synchronized real-time therapy sessions.
  • Choose a stimulation mode: Visual, Audio, or Visual and audio.
  • Control stimulus parameters (speed, pattern, color, size, volume) in real-time.
  • Listen to the tones on your own device while monitoring the session.
  • Track SUDS and VOC ratings with integrated target memory management directly in-session.
  • Share a secure, distraction-free link with patients.
  • Use temporary sessions for one-off use or permanent sessions for ongoing treatment.
  • Link sessions to specific patients for easier management.

Getting Started

To use the tool, navigate to Features > Tools > Bilateral Stimulation.

Creating a Session

  1. Assign Patients (Optional): Select one or more patients to associate with this session. This helps in tracking which tool was used with which patient, and is required to record SUDS and VOC ratings during the session.
  2. Permanent Link:
    • Checked: The session link remains valid indefinitely. Ideal for patients you see regularly.
    • Unchecked: The session is temporary and expires after 24 hours of inactivity.
  3. Click Generate Session Link.

Once the session is created, you will see the Therapist Control Panel.

Therapist Control Panel

The control panel allows you to manage the stimulus and the session status. A Stimulus Preview shows exactly what the patient sees.

Session Controls

  • Start: Begins the stimulation.
  • Pause: Temporarily stops the stimulus at its current position.
  • Resume: Continues the stimulation from where it was paused.
  • Terminate: Stops the stimulus and resets its position.
  • Session Timer: Automatically tracks the duration of the active stimulus during the session, next to the current session status.

Stimulus Settings

Adjust these settings at any time; changes are synchronized instantly to the patient's view:

  • Speed: Adjust how fast the stimulus moves (from 1 - slow to 10 - fast).
  • Stimulus Pattern: Choose the movement path:
    • Horizontal: Moves left to right (standard EMDR).
    • Vertical: Moves up and down.
    • Diagonal: Moves from corner to corner.
  • Stimulation Mode: Choose how the stimulation is delivered:
    • Visual: A moving dot only (default).
    • Audio: Alternating tones only.
    • Visual and audio: The moving dot, with a tone each time it reaches an edge.
  • Volume: Set the volume of the tones (from 0% to 100%). Only shown when the mode includes audio.
  • Stimulus Color: Select a color that is most comfortable or effective for the patient.
  • Size: Adjust the diameter of the stimulus dot.
  • SUDS/VOC Tracker: Turn on in-session target memory tracking (see below).

Every setting is saved with the session, so a permanent session resumes with the same setup.

Audio Stimulation

Auditory bilateral stimulation plays a short tone that alternates between the patient's ears:

  • A tone plays in the left ear when the stimulus reaches its starting edge, and in the right ear when it reaches the opposite edge, whatever the pattern.
  • The tones follow the Speed setting, so they stay in step with the moving dot in Visual and audio mode.
  • Pausing or terminating the session silences the tones immediately.

In Audio mode, the moving dot is replaced by two circles at either end of a line, one for each side. The circle on the side of the current tone lights up and ripples as the tone plays.

Headphones: The patient needs headphones to hear the tones alternate between ears. Through speakers, both tones are heard in both ears.

Listening on Your Device

To hear the tones yourself, turn on Listen on this device in the control panel. This only affects your own device: the patient hears the tones whether or not you are listening.

In-Session SUDS & VOC Tracking

When the SUDS/VOC Tracker is turned on for the session:

  • An interactive tracking panel appears below the stimulus preview.
  • You can select or create an EMDR Target Memory for the assigned patient. If the session has several patients, first choose who the target memory belongs to. If no patient is assigned, assign one to the session to record ratings.
  • Between stimulation sets, pause the stimulus and log the patient's SUDS (0–10) and VOC (1–7) ratings for the current protocol phase.
  • Set Numbers increment automatically with each logged pass (Set 1, Set 2, Set 3...).
  • The Desensitization Curve updates live in your panel, providing immediate visual feedback on the patient's reprocessing progress.

For an in-depth guide on target memories, rating scales, and protocol phases, see SUDS & VOC Tracker.

Patient View

The Patient View is a simplified interface designed to minimize distractions, showing only the stimulus on a clean background.

  1. In the Therapist Control Panel, locate the Client Access Link in the Session Info section.
  2. Click the copy icon to copy the secure URL to your clipboard.
  3. Send this link to your patient via chat, email, or your preferred communication method.

When the patient opens the link, they will see the stimulus reacting to your controls in real-time. No login is required for the patient to access this view. Until you start the session, the patient sees a message asking them to wait for their therapist, along with the link they opened, so you can check you are both using the same session.

Hearing the Tones

When the mode includes audio, the patient view shows a sound panel at the bottom of the screen:

  1. The patient clicks Enable sound. Browsers block sound until the patient interacts with the page, so this step is required once per visit.
  2. Once sound is enabled, the patient can mute the tones or lower them with their own volume slider. These controls only affect the patient's device and work on top of the volume you set.

If the patient can't hear the tones, check that:

  • The mode is set to Audio or Visual and audio, and the session is running.
  • The patient clicked Enable sound and has not muted the tones.
  • Your Volume and the patient's own volume are above zero, and their device is not muted.
  • Their browser supports sound. If it doesn't, the panel shows "Sound is not available in this browser."

Privacy Note: Even when SUDS & VOC tracking is enabled in the therapist panel, the patient view remains strictly focused on the stimulus. Target titles, cognitions, rating sliders, and clinical notes are never displayed on the patient's screen.

Session Management

The tool maintains a history of your sessions under Saved Sessions, allowing you to quickly jump back into a previous setup or manage existing permanent links. Each session shows whether it is permanent or temporary, and which patients it is linked to.

  • Load Session: Click on a previous session from the list to resume it.
  • Delete Session: Permanently remove a session and invalidate its link. Any patient connected to it is disconnected immediately.