Wearable Devices for Multimodal Optical Diagnostics of Microcirculatory-Tissue Systems: Application Experience in the Clinic and Space

Abstract

This work demonstrates some results of the successful experience of using wearable devices for multimodal optical diagnostics of microcirculatorytissue systems both in clinical practice and in the conditions of a Space experiment. The multimodal approach based on simultaneously applying a minimum of 2 optical diagnostic methods, for example, laser Doppler flowmetry and fluorescence spectroscopy, allows analysing of blood flow and metabolic processes in biological tissue more systematically. Combining several wearable devices into a distributed diagnostic system allows placing them simultaneously on symmetrical parts of the body (such as opposite limbs) thus providing a possibility to study the symmetry of the measured signals. The obtained data on the state of the microcirculatory-tissue systems of the human body recorded with wearable multimodal devices make it possible to assess the relationship and dynamics of oxygen delivery and utilization by tissues more comprehensively and reliably in a variety of diagnostic tasks.

Sampling volume assessment for wearable multimodal optical diagnostic device

“…Due to the high requirements for probing and receiving parts of LDF devices (radiation sources in the form of single-mode lasers, radiation receivers, delivery, and reception systems of radiation from biological tissues), there have so far been very few studies on the possibility of miniaturization and development of wearable devices [14,15], allowing to significantly increase the convenience of their application and, consequently, expand their field of implementation in clinical practice. However, due to the development of miniaturized laser sources (first of all, vertical-cavity surface-emitting lasers [VCSEL]), a significant breakthrough has been made in this area recentlywearable devices "LAZMA PF" (LAZMA Ltd, Russia; in EU/UK this device made by Aston Medical Technology Ltd., UK as "FED-1b") implementing LDF, FS, cutaneous thermometry, and accelerometry channels, operating directly without optical fiber and transmitting measurement data to a PC using Bluetooth or Wi-Fi protocols [16,17]. The appearance of the wearable multimodal devices implementing LDF and FS methods is shown in Figure 1.…”

“…These devices are gradually finding their application in medical practice, especially in the diagnosis of complications associated with diabetes mellitus [18,19], hypertension [20], have been tested in the assessment of smoking status [21], effectiveness of drug therapy for microcirculatory disorders [22], in assessing the influence of the body position on microcirculation parameters [23], assessment of blood microcirculation changes after COVID-19 [24] and under the microgravity conditions during the Space flight [17,25]. However, for their wider introduction into clinical practice, additional research is required, and first of all, it is necessary to substantiate specialized medical and technical requirements of metrological nature [26], taking into account the peculiarities of design of these wearable multimodal devices.…”

Correlation between the Capillary Blood Flow Characteristics and Endothelium Function in Healthy Volunteers and Patients Suffering from Coronary Heart Disease and Atrial Fibrillation: A Pilot Study

“…During the last few decades, laser Doppler flowmetry has emerged as an efficient technique for studying the blood perfusion and microcirculation disorders in different diseases [13]. Recently, portable devices that enable the researchers to conduct measurements in various experimental conditions, including microgravity, have been designed [14]. Additionally, a variety of interesting studies of phenomena related to blood and lymph microcirculation in the brain of laboratory animals have been performed using the speckle correlation microscopy technique [15,16].…”