Are you familiar with Steven C Kassel, MFT ? This is from HIS Website:
Interpersonal Biofeedback is a promising new area of study and clinical practice. It is a hybrid of two evidence based therapies, Biofeedback and Psychotherapy, where information of physiology, such as heart rate, heart rate variability, brain waves, hand temperature, sweat gland activity, and/or respiration are given back to more than one person at a time to help them learn how to tone down nervous system arousal or better tune-in to one another. The first research paper that appeared was in 1978, by family therapist and theorist Michael Kerr, in which he discussed biofeedback may be used to help families.