Non-Invasive Capillary Blood Pressure Measurement Enabling Early Detection and Classification of Venous Congestion

Non-Invasive Hemodynamic Monitoring System Integrating Spectrometry, Photoplethysmography, and Arterial Pressure Measurement Capabilities

Minimally invasive and non-invasive hemodynamic monitoring technologies have recently gained more attention, driven by technological advances and the inherent risk of complications in invasive techniques. In this article, an experimental non-invasive system is presented that effectively combines the capabilities of spectrometry, photoplethysmography (PPG), and arterial pressure measurement. Both time- and wavelength-resolved optical signals from the fingertip are measured under external pressure, which gradually increased above the level of systolic blood pressure. The optical channels measured at 434-731 nm divided into three groups separated by a group of channels with wavelengths approximately between 590 and 630 nm. This group of channels, labeled transition band, is characterized by abrupt changes resulting from a decrease in the absorption coefficient of whole blood. External pressure levels of maximum pulsation showed that shorter wavelengths (<590 nm) probe superficial low-pressure blood vessels, whereas longer wavelengths (>630 nm) probe high-pressure arteries. The results on perfusion indices and DC component level changes showed clear differences between the optical channels, further highlighting the importance of wavelength selection in optical hemodynamic monitoring systems. Altogether, the results demonstrated that the integrated system presented has the potential to extract new hemodynamic information simultaneously from macrocirculation to microcirculation.

The 2023 wearable photoplethysmography roadmap

Photoplethysmography is a key sensing technology which is used in wearable devices such as smartwatches and fitness trackers. Currently, photoplethysmography sensors are used to monitor physiological parameters including heart rate and heart rhythm, and to track activities like sleep and exercise. Yet, wearable photoplethysmography has potential to provide much more information on health and wellbeing, which could inform clinical decision making. This Roadmap outlines directions for research and development to realise the full potential of wearable photoplethysmography. Experts discuss key topics within the areas of sensor design, signal processing, clinical applications, and research directions. Their perspectives provide valuable guidance to researchers developing wearable photoplethysmography technology.

Brazilian guidelines on chronic venous disease of the Brazilian Society of Angiology and Vascular Surgery

The Brazilian Society of Angiology and Vascular Surgery has set up a committee to provide new evidence-based recommendations for patient care associated with chronic venous insufficiency. Topics were divided in five groups: 1. Classification, 2. Diagnosis, 3. Conservative or non-invasive treatment, 4. Invasive treatment and 5. Treatment of small vessels. This last series is closely related to the activities of Brazilian angiologists and vascular surgeons, who are heavily involved in the treatment of small superficial veins. These guidelines are intended to assist in clinical decision-making for attending physicians and health managers. The decision to follow a guideline recommendation should be made by the responsible physician on a case-by-case basis taking into account the patient's specific condition, as well as local resources, regulations, laws, and clinical practice recommendations.