Comparative Utility of Biofeedback Parameters in Predicting Perceived Relaxation

Abstract

Background: Biofeedback is a mind-body technique where individuals track their biological functions to decrease stress. Aims and Objectives: There were two objectives in this study: (1) Understand the changes in biofeedback measurements, such as changes in respiration rate and skin temperature, during relaxation and (2) Correlate these changes to their perceived relaxation, which can help determine if certain biofeedback methods can quantify the extent of relaxation. Materials and Methods: Eleven volunteers of 55 ± 3 years were relaxed for 11 min in a controlled environment using a session from the “Calm” app. Four biofeedback parameters were measured during the relaxation period (skin temperature, heart rate, respiration rate, and skin resistance). Postrelaxation, subjects completed a questionnaire to report the changes in their perceived relaxation state. Average skin resistance significantly increased from 314.75 Ω to 393.33 Ω (P = 0.04, two-tailed paired t-test). The changes in all other parameters were statistically insignificant, with the average skin temperature increasing from 86.55°F to 88.04°F (P = 0.24), heart rate decreasing from 71.90 bpm to 71.36 bpm (P = 0.51), and respiration rate decreasing from 14.82 rpm to 14.72 rpm (P = 0.88). All participants reported some degree of relaxation. However, there was no significant correlation between the parameters and degree of subjective relaxation (P > 0.05, Pearson's test). Conclusion: Only skin resistance showed a statistically significant change over the relaxation period, coinciding generally with the volunteers' perception of increased relaxation.