Challenges Presented by Cuffless Measurement of Blood Pressure if Adopted for Diagnosis and Treatment of Hypertension.

The global health burden presented by hypertension is providing increased motivation for improved means of collection of blood pressure (BP) data. A growing area of research and commercial activity is the use of wearable devices to provide BP data using non-invasive cuffless techniques. The accelerated progress in recent years, particularly relating to connectivity of smartphone technology, has promoted the availability of consumer devices that provide values of BP.

Blood pressure-independent neurogenic effect on conductance and resistance vessels: a consideration for cuffless blood pressure measurement?

Background: Pulse transit time (PTT) and pulse arrival time (PAT) are promising measures for cuffless arterial blood pressure (BP) estimation given the intrinsic arterial stiffness-BP relationship. However, arterial stiffness (and PTT) is altered by autonomically-driven smooth muscle tension changes, potentially independent of BP. This would limit PTT or PAT as accurate BP correlates, more so in resistance vessels than conductance arteries.

Contactless video-based photoplethysmography technique comparison investigating pulse transit time estimation of arterial blood pressure.

Background: Non-contact measurement of physiological vital signs, such as blood pressure (BP), by video-based photoplethysmography (vPPG) is a potential means for remote health monitoring. However, the signal-to-noise ratio of cardiovascular signals within the vPPG is very low.

Objective: This study investigates the potential of BP estimation from vPPG.

Sensitivity of Video-Based Pulse Arrival Time to Dynamic Blood Pressure Changes.

Estimating blood pressure (BP) from pulse arrival time (PAT) by image-based (skin video) photoplethysmography (iPPG) is of increasing interest due to the non-contact method advantage (over cuff-based methods) and potential for BP measurement to be built into portable devices such as mobile phones. The relationship between pulse transit time extracted from iPPG has been investigated during stable BP. The sensitivity of beat-to-beat iPPG-PAT to dynamic changes in BP has not been explored.

Effects of instructed meditation augmented by computer-rendered artificial virtual environment on heart rate variability.

Previous research has supported the use of virtual reality (VR) to decrease stress, anxiety, perceptions of pain, and increase positive affect. However, the effect of VR on blood pressure (BP) and autonomic function in healthy populations have not been explored. This study quantifies the effect of instructed meditation augmented by a virtual environment (VE) on BP and heart rate variability (HRV) during rest and following physical (isometric handgrip) or mental (serial sevens subtraction) stress.

Cuffless Estimation of Blood Pressure: Importance of Variability in Blood Pressure Dependence of Arterial Stiffness Across Individuals and Measurement Sites.

Objective: Measuring arterial pulse transit time (PTT) to estimate blood pressure (BP) without conventional brachial cuff-based measurement is not new, but is a focus of current wearable technologies research. Much research pertains to efficient, accurate sensing of artery-related waveforms, yet the relationship between PTT and BP receives less attention despite being key for accurate BP estimation. This study investigated BP/PTT calibration by quantifying anatomical site variability (n = 10, 3 female, age 30 9 years) and individual variability ( n = 103, 50 female, age 53 22 years).

Characterisation of cardiac autonomic function in multiple sclerosis based on spontaneous changes of heart rate and blood pressure.

Background: Prevalence of cardiovascular autonomic dysfunction (CAD) in multiple sclerosis (MS) varies between studies. Cardiac autonomic function is usually assessed by cardiovascular reflex tests. We hypothesized that MS is associated with CAD, quantifiable by non-invasive means including quantification of baroreceptor sensitivity (BRS) and heart rate variability.