Alternative Presentations of HRV Feedback

We take a design perspective, being interested in creating biofeedback systems which empower their users in matters of health and coping with stress. Taking a design perspective also means trying to understand the working of the full loop, which includes both the user and the biofeedback device(s). The form-giving of the feedback to the user is an important design issue, which is still largely unexplored. We will show some of our explorations, including a new representation called circle maps, based on Poincare plots. Their usage for real-time feedback is new to the best of our knowledge. In our demonstration, we will show three structural designs for feedback, viz. (1) Representation of calculated HRV, (2) Representation of successive beat-to-beat intervals, and (3) Circle plot (modified Poincare plot). We developed a form-giving in which all aspects are kept the same (in-as-far possible), except for the structural design. We will discuss the strong and weak points of the three designs on criteria such as outlier robustness, information richness, and narrative adaptability. It is also possible to combine several approaches or to even present all three types of information to the user. The resulting feedback loop then becomes like a PID controller (proportional-integrating-differentiating--often used for mechanical feedback control systems). The calculated HRV, with its cumulative effect is like the I (integrated signal). The representation of successive beat-to-beat intervals is like the P (proportional, direct, and untransformed signal). The representation by the circle plots is like the D (the differential of successive signals). We do not yet have proper quantitative tests to demonstrate which displays best teach HRV increase or control. Possibly, next year we will share such results or our preliminary experiences with the BFE community. In either case, we will demonstrate the prototype at work.