Biomelodics

rob@robburke.NOSPAM.netNOSPAM
Robert Burke

mind games
thanks to the entire group

Biomelodics is application that uses acoustic and visual biofeedback controlled by an adaptive learning mechanism to encourage a participant to maintain a constant heart rate.

In the current experimental setup, a participant begins by selecting a piece of music with a known beats-per-minute ratio. The participant then listens to that music, which is warped so that the beats of the song are, as close as possible, concurrent with the beats of the participant’s heart. The participant's heartbeat is also made audible as a drum beat layered on top of the song. The music will sound "warped" until the participant is able to bring their heart beat frequency close to the song's original beat frequency.

Biomelodics incorporates a learning mechanism that discovers which of a variety of parameterized techniques is most effective for reducing the difference between the current and target heart rates. When a significant difference is observed between these two rates, the mechanism can elect to experiment with different techniques for reducing the difference. Some of the techniques used are auditory in nature, while others are visual. Over multiple sessions, the system learns which techniques most reliably lead to an increase or decrease in heart rate, and uses the most reliable techniques with greater frequency.

While listening to the song, the participant is presented with a visualization of several metrics related to cardiac function. A graph is drawn in real-time to show the participant’s current heart rate and its relationship to the target heart rate (see images, left and below). Two thresholds are indicated around the target heart rate: a “target heart rate region” in which they are meant to maintain their heart rate, and another region 150% larger than the target region that indicates proximity to the target region. Heart rate variability is indicated by the width of the line used to indicate the current heart rate. Finally, an ECG (electrocardiograph) wave is drawn to indicate the electrical activity of the heart.

The utility of such an exercise is motivated by findings that conscious physiological control of heart rate can be increased using biofeedback techniques, and diverse real-world applications that require a participant to maintain a steady heart rate that is possibly quite different from their resting heart rate, such as relaxation exercises to reduce hypertension, and schedules of physical exercise.

We are encouraged by initial results with Biomelodics, and will continue to pursue techniques for improving its adaptive learning mechanism. Such a mechanism, if robust and intuitive, could be useful for designing a variety of more intelligent biofeedback techniques.