Our healthy lifestyle requires a personalized healthy diet and balanced physical activities. All of these will in principle be possible with personal trainers and dietologists. Why the development of continuous monitoring of human health and activity wireless wearable devices will be one of the key technologies in the ubiquitous sensor network society for years to come. The wearable device developed is based on laser Doppler flowmetry, which is used for functional evaluation of the circulatory system. We here present wearable laser Doppler flowmetry sensors based on compact VCSEL with Wi-Fi/Bluetooth data transfer in examining health, diabetic, and smoking volunteers. The developed wearable devices consist of three channels for recording blood perfusion, skin temperature, and movements. This allows for measurement at any desirable point of the human body. The system also comprises a wireless data acquisition module. Signal processing based on wavelet transformation has shown that the proposed sensor can detect five frequency rhythms by analysis of the small arteries blood flow oscillations: endothelial, neurogenic, myogenic, respiratory, and pulse rhythm. Overall, a series of studies of healthy volunteers, non- and smoking, at different gravity position, and diabetic patient have shown that wearable device(s) is capable of differentiating cardiovascular parameters with high sensitivity. Our promising results demonstrate the robustness of both the data acquisition and the spectral analysis methods employed to characterise measured optical data.

First responders often face chaotic and noisy scenes when arriving at the site of an accident. In such environments it is challenging to assess and monitor multiple patients. Sensors such as pulse oximeters have limited usability in field settings, especially if the users are not professionally trained. There is therefore a need for an easy-to-use solution to monitor vital signs such as pulse and breathing rate. To meet this need, a combined optic-acoustic vital signs monitor has been developed. This paper is focusing on the development and testing of the optical sensor unit, and data from testing of the sensor will be presented.

We present the creation of wearable devices that measure transcutaneous partial oxygen or carbon dioxide pressure (tcpO2 or tcpCO2) non-invasively. The devices are highly sensitive to the physiological pO2/pCO2, and detects changes in luminescence (lifetime or ratiometric brightness) of mellaporphyrins or HPTS dye molecules embedded within breathable, hydrophobic films. Our first in human measurements reveal the devices are able to detect quick and subtle changes in tcpO2 due to local and systemic changes in blood flow of skin or deeper muscle tissue. Models to extract tissue oxygenation and oxygen consumption rate are explored.

Non-invasive approaches to human data collection have become relevant in athlete performance monitoring and the clinical setting. Historically, these metrics rely on measurements such as blood or tissue oxygen saturation, yet saturation lacks a degree of specificity clinicians and professional trainers desire. To overcome this, we developed a wearable, non-invasive, optical transcutaneous tissue oxygenation sensor that overcomes inefficiencies in specific measurements and the devices that collect those measurements. We report on innovations to the prototype device, including the implementation of more sophisticated quantification methods directly on the device as well as the addition of new sensors to measure other clinical parameters.

An oxygen-sensing microneedle array (MNA) was developed to monitor oxygen partial pressure in tissue in a minimally invasive fashion. The working principle is based on the quenching of emission intensity and phosphorescence lifetime of a Pt-core porphyrin embedded into the MNA. It was shown that the MNA is sufficiently robust to puncture human skin and to detect changes in oxygenation within the physiologically relevant range of 0-160 mmHg. Moreover, it was demonstrated that the MNA can be implemented into a wearable wireless optical readout system rendering the MNA a novel and user-friendly technique to monitor oxygen partial pressure in tissue.

Absorption of light by epidermal melanin can confound light-based measurements of tissue oxygenation, reducing the ability of these technologies to reliably identify hypoxia. Spatial frequency domain imaging (SFDI) may help address this critical concern, because the different spatial frequencies of light penetrate different depths into the tissue, facilitating separation between contributions of different tissue layers to the detected signal. Here, we rigorously investigate the relationship between the skin tone of healthy subjects and the tissue oxygen saturation (StO2) measured with multispectral SFDI. This study helps to quantify the degree to which skin tone influences SFDI measurements of tissue oxygenation.

This presentation will discuss the use of dermal water concentration analysis by in vivo Raman spectroscopy for the assessment of a person's hydration status.

In this study, we propose a new approach to measuring tissue oxygenation with near-infrared spectroscopy using a single source-detector separation. This method is based on the difference in absorbance at three wavelengths before, at, and after the isosbestic point. The accuracy of tissue oxygenation measurement using the multiwavelength method was tested using Monte Carlo simulation and spatially resolved spectroscopy. Tissue oxygenation calculated from a single source-detector separation using multiwavelength was similar to one calculated from two source-detector separations using the spatially resolved method. This suggested method can help to simplify a tissue oximeter.

The experimental group performed whole-body ST twice a week, at 75% intensity of one-repetition, for 10 weeks during winters (EX, n=8). The control group did not perform ST (CT, n=12). Parameters of BAT activity, like BAT vascular density (BAT-d) and skin temperature in the supraclavicular region (Tsup) during ST and resting fat oxidation (FO) were measured before and after the intervention. ΔBAT-d did not significantly differ between the EX and CT groups. Significant inverse correlations were found between Tsup and ∆%BF and ∆FO. These results suggest that an elevated Tsup is related to systemic body fat reduction.

The COVID-19 outbreak in 2019 is still a pandemic due to its strong contagiousness and viability. In order to prevent the spread of COVID-19, a non-contact monitoring system is needed. COVID-19 patients show symptoms similar to acute viral pneumonia. Because of this, COVID-19 patients are characterized by faster and shallower breathing than normal people. These respiratory status changes affect tissue oxygenation status. In this paper, we develop a system for monitoring changes in tissue oxygenation status in real time using NIRS sensors and classifies breathing patterns using deep learning algorithm.

We have developed a wearable and wireless near-infrared spectroscopy (NIRS) device to monitor fetal heart rate and heart rate variability. The device was applied to measure NIRS signals in 12 pregnant volunteers in their second and third trimesters. The fetal heart rate calculated from these NIRS signals is consistent with the fetal heart rate measured from a continuous Doppler ultrasound device. This result suggests a potential of a wireless, wearable, and affordable device to monitor fetal well-being continuously. If successful, this device will be extremely helpful to low-income populations who have limited access to modern healthcare.

Humans must keep their bodies' levels of oxygen in balance to stay healthy. Hypoxia, which is common in respiratory illnesses such as pneumonia, the flu, and COVID-19, is a state in which there is insufficient oxygen in the tissues to maintain appropriate homeostasis. Using a customized multimodal biosensor device, the aim of this observational study is to develop a point-of-care method for screening and monitoring individuals with infectious respiratory diseases.

Wearable pH sensors have provided relevant Information on health status with applications in infection detection, disease diagnosis, and personalized medicine. Presently used pH devices have often been expensive with poor flexibility and required bulky and complicated readout instruments that need skilled personnel, thus inappropriate for clinical applications and remote health monitoring. Herein, we proposed, developed, and fully characterized, a miniaturized, modular, battery-free, biocompatible, flexible, 3D-printed (WB2F3D) sensor system integrated with a reusable near-field communication (NFC) module for the on-demand, wireless, and real-time pH monitoring. Direct ink writing (3D printing) was applied to print sensors integrated with the NFC-based circuit and antenna on a highly flexible substrate, with human skin-like mechanical characteristics, in a low-cost and time-efficient manner. The flexible NFC-based readout circuit system enabled wireless energy harvesting and data transmission with smartphones, providing real-time, on-demand and continuous pH monitoring. The WB2F3D sensor system exhibited high sensitivity (~ |51.8| mV/pH), specificity, repeatability, and reproducibility toward various pH ranges (3.0 – 10.0) with mechanical stability and flexibility, ideal for continues wound healing monitoring. The system's utility for on-demand, wireless, and real-time health monitoring was successfully demonstrated by ex-situ and in-situ monitoring of pH values. The biocompatibility of the sensors was confirmed through the cell viability of murine muscle cells. The sensor system was demonstrated to successfully monitor the pH changes in the ex-situ hydrogel wound model for a practical application. Our WB2F3D sensor system provides an integrated platform for accurate, on-demand, and wireless measurements without discomfort to facilitate real-time human health monitoring.

The current standard of care for evaluating obstructive sleep apnea (OSA) is polysomnography (PSG), which requires a resource-intensive overnight study and relies on pulse oximetry to determine severity. PSG does not provide direct information about brain oxygenation, but studies have demonstrated that near-infrared spectroscopy (NIRS) technology can be useful in monitoring cerebral hemodynamics. These studies largely rely on commercial bedside tissue oxygenation monitors, although more portable instruments could permit use in home settings. In this work, we evaluate a prototype smartphone compatible NIRS device for assessing OSA, examine hemodynamic responses alongside PSG, and derive two novel metrics for disease severity.