A novel stress monitoring method through stress-induced respiratory alterations: non-contact measurement of respiratory V(T)/T(I) alterations induced by stressful sound using a 10 GHz microwave radar

Simple and objective screening of major depressive disorder by heart rate variability analysis during paced respiration and mental task conditions

Since objective biomarkers for major depressive disorder (MDD) are not readily available, clinical psychiatrists diagnose patients with MDD subjectively based on clinical interviews and diagnostic criteria. It often raises various concerns, including false responses by patients, subjective factors, and inexperience of the attendants leading to incorrect diagnosis. Here, we developed a self-monitoring system for simple and objective screening of MDD using a photoplethysmography (PPG) sensor and a 24-GHz microwave radar, which was based on the analysis of heart rate variability (HRV) during paced respiration and mental task conditions. In our previous study, we assessed the reactivity of HRV measurements during a mental task (random number generation) condition in patients with MDD and healthy control subjects. The HRV indices are less reactive in patients with MDD compared to healthy subjects during the mental task, which enabled us to identify the patients at risk for depression. In this study, the reactivity of HRV was measured not only in the mental task but also during paced respiration (i.e., 5-s inhalation and 5-s exhalation) conditions, thereby assessing more detailed autonomic nervous system (ANS) activity via HRV indices. To investigate the effect of paced respiration on MDD screening, we compared the ANS activity via HRV indices in with/without paced respiration conditions in 28 drug-naïve patients with MDD and 27 healthy control subjects. The result showed that ANS significantly activated during the paced respiration condition (p<;0.05). The sensitivity in detecting patients with MDD was 86% under paced respiration and mental task conditions, which was higher than the sensitivity (68%) under mental task condition alone.

PSYCHOPHYSIOLOGICAL CHARACTERISTICS OF WOMEN IN DEPENDENCE ON THE OVARIOHORMONAL CYCLE PHASE AND PROGESTERONE ACTIVITY (PART 1)

With the aim to identify the effects of menstrual cycle phase on the cognitive and psycho-emotional characteristics in 78 women aged 18–27 years were studied in a within-subject design Half the subjects began during their follicular phase and half began during their luteal phase (LP). The level of psycho-emotional tension was lowest, but cognitive performance efficiency is a highest in LP that is associated with the highest saliva progesterone level.

Non-verbal communication of compassion: measuring psychophysiologic effects

BACKGROUND

Calm, compassionate clinicians comfort others. To evaluate the direct psychophysiologic benefits of non-verbal communication of compassion (NVCC), it is important to minimize the effect of subjects' expectation. This preliminary study was designed to a) test the feasibility of two strategies for maintaining subject blinding to non-verbal communication of compassion (NVCC), and b) determine whether blinded subjects would experience psychophysiologic effects from NVCC.

METHODS

Subjects were healthy volunteers who were told the study was evaluating the effect of time and touch on the autonomic nervous system. The practitioner had more than 10 years' experience with loving-kindness meditation (LKM), a form of NVCC. Subjects completed 10-point visual analog scales (VAS) for stress, relaxation, and peacefulness before and after LKM. To assess physiologic effects, practitioners and subjects wore cardiorespiratory monitors to assess respiratory rate (RR), heart rate (HR) and heart rate variability (HRV) throughout the 4 10-minute study periods: Baseline (both practitioner and subjects read neutral material); non-tactile-LKM (subjects read while the practitioner practiced LKM while pretending to read); tactile-LKM (subjects rested while the practitioner practiced LKM while lightly touching the subject on arms, shoulders, hands, feet, and legs); Post-Intervention Rest (subjects rested; the practitioner read). To assess blinding, subjects were asked after the interventions what the practitioner was doing during each period (reading, touch, or something else).

RESULTS

Subjects' mean age was 43.6 years; all were women. Blinding was maintained and the practitioner was able to maintain meditation for both tactile and non-tactile LKM interventions as reflected in significantly reduced RR. Despite blinding, subjects' VAS scores improved from baseline to post-intervention for stress (5.5 vs. 2.2), relaxation (3.8 vs. 8.8) and peacefulness (3.8 vs. 9.0, P < 0.05 for all comparisons). Subjects also had significant reductions in RR (P < 0.0001) and improved HRV (P < 0.05) with both tactile and non-tactile LKM.

CONCLUSION

It is possible to test the effects of LKM with tactile and non-tactile blinding strategies; even with blinding in this small preliminary study, subjects reported significant improvements in well-being which were reflected in objective physiologic measures of autonomic activity. Extending compassion is not only good care; it may also be good medicine.

TRIAL REGISTRATION NUMBER

US National ClinicalTrials.gov registration number, NCT01428674.