Test-retest reliability of a photographic marker-based system for postural examination.

BACKGROUND: The BHOHB system (Bhohb S.r.l., Italy) is a portable non-invasive photographic marker-based device for postural examination. OBJECTIVE: To assess the test-retest reliability of the BHOHB system and compare its reliability with an optoelectronic system (SMART-DX 700, BTS, Italy). METHODS: Thirty volunteers were instructed to stand upright with five markers on the spinous processes of C7, T6, T12, L3 and S1 vertebrae to define the dorsal kyphosis and lumbar lordosis (sagittal plane) angles. Three markers were placed on the great trochanter, apex of iliac crest and lateral condyle of the femur to detect pelvic tilt. Finally, to define angles between the acromion and the spinous processes (frontal plane), two markers were placed on the right and left acromion. Postural angles were recoded simultaneously with BHOHB and optoelectronic systems during two consecutive recording sessions. RESULTS: The BHOHB system revealed excellent reliability for all the angles (ICCs: 0.92-0.99, SEM: 0.78∘-3.33∘) as well as a shorter processing time compared to the optoelectronic system. Excellent reliability was also found for all the angles detected through the optoelectronic system (ICCs: 0.91-0.99, SEM: 0.84∘-2.80∘). CONCLUSION: The BHOHB system resulted as a reliable non-invasive and user-friendly device to monitor spinal posture, especially in subjects requiring repeat examinations.

Contactless Vital Signs Monitoring From Videos Recorded With Digital Cameras: An Overview.

The measurement of physiological parameters is fundamental to assess the health status of an individual. The contactless monitoring of vital signs may provide benefits in various fields of application, from healthcare and clinical setting to occupational and sports scenarios. Recent research has been focused on the potentiality of camera-based systems working in the visible range (380-750 nm) for estimating vital signs by capturing subtle color changes or motions caused by physiological activities but invisible to human eyes. These quantities are typically extracted from videos framing some exposed body areas (e.g., face, torso, and hands) with adequate post-processing algorithms. In this review, we provided an overview of the physiological and technical aspects behind the estimation of vital signs like respiratory rate, heart rate, blood oxygen saturation, and blood pressure from digital images as well as the potential fields of application of these technologies. Per each vital sign, we provided the rationale for the measurement, a classification of the different techniques implemented for post-processing the original videos, and the main results obtained during various applications or in validation studies. The available evidence supports the premise of digital cameras as an unobtrusive and easy-to-use technology for physiological signs monitoring. Further research is needed to promote the advancements of the technology, allowing its application in a wide range of population and everyday life, fostering a biometrical holistic of the human body (BHOHB) approach.