Non-Invasive Muscular Atrophy Causes Evaluation for Limb Fracture Based on Flexible Surface Electromyography System.

Muscular atrophy after limb fracture is a frequently occurring complication with multiple causes. Different treatments and targeted rehabilitation procedures should be carried out based on the causes. However, bedside evaluation methods are invasive in clinical practice nowadays, lacking reliable non-invasive methods. In this study, we propose a non-invasive flexible surface electromyography system with machine learning algorithms to distinguish nerve-injury and limb immobilization-related atrophy. First, a flexible surface electromyography sensor was designed and verified by in vitro tests for its robustness and flexibility. Then, in vivo tests on rats proved the reliability compared with the traditional invasive diagnosis method. Finally, this system was applied for the diagnosis of muscular atrophy in 10 patients. The flexible surface electromyography sensor can achieve a max strain of 12.0%, which ensures close contact with the skin. The in vivo tests on rats show great comparability with the traditional invasive diagnosis method. It can achieve a high specificity of 95.28% and sensitivity of 98.98%. Application on patients reaches a relatively high specificity of 89.44% and sensitivity of 91.94%. The proposed painless surface electromyography system can be an easy and accurate supplementary for bedside muscular atrophy causes evaluation, holding excellent contact with the body.

Flexible wound healing system for pro-regeneration, temperature monitoring and infection early warning.

To break the "Black-Box" status of the wound healing process under traditional dressing, which cannot achieve satisfactory repair outcome of skin wounds, a wound healing system with the abilities of pro-regeneration and real-time monitoring of wound status has become a considerable necessity. Here, by integrating the emerging bioelectronics and software, we created a flexible wound healing system. The hardware system was designed as Band-Aid shaped with a double-layer structure; the upper is the flexible temperature-sensing layer comprising the temperature sensor STH21, power manager circuit and data processing circuit, and the lower is a collagen-chitosan dermal equivalent for skin regeneration. A customized software application (app) installed on a smartphone to receive data from the sensing layer by BLE4.0 can display and analyze real-time wound temperature. Our system had high monitoring sensitivity and stability, good stretchability, excellent reliability and biocompatibility. It was applied to a pig skin wound model to reveal temperature fluctuation during the entire wound regeneration process. As a credible reference and foundation for further early warning of an adverse event, three main phases of temperature fluctuation were found: the rising phase (below 39 °C), plateau phase (39-39.5 °C), and falling phase (below 39 °C), which were accompanied by significant wound biological events, including inflammatory cell infiltration, angiogenesis and wound healing. Furthermore, verified by wound infection models of different healing phases and wound Gram's staining, early warning ahead of serious infection was realized with the use of a customized app's alarm.

Stretchable Optical Sensing Patch System Integrated Heart Rate, Pulse Oxygen Saturation, and Sweat pH Detection.

OBJECTIVE: Continuous measurement of key physiological parameters, such as heart rate (HR), pulse oxygen saturation (SpO2), and sweat pH value, has very broad applications in healthcare, disease surveillance, and fitness and sports training. In this study, a stretchable optical sensing patch system was developed for real-time continuous noninvasive monitoring of the HR, SpO2, and sweat pH, and the sensing data were transmitted to a smartphone through Bluetooth. METHODS: The sensor patch system adopted serpentine stretchable interconnects between the optical sensor and microcontroller chip with wireless function on a flexible substrate. The pH sensing function was implemented by coating a pH sensitive organically modified silicate film on the surface of a commercial blood oxygen sensor, achieving simultaneous measurement of HR, SpO2, and sweat pH with a single sensor. RESULTS: Real-time on-body assessment was carried out to evaluate the sensor patch system, showing its excellent repeatability and applicability. The sensor patch system could withstand up to 35% extension and exhibited a pH sensitivity of 4.42 mV/pH from 4.0 to 8.0, while the accuracy of HR from 25 to 250 b/min and SpO2 from 70% to 100% sensing were ±1 b/min and ±2%, respectively. CONCLUSION: The triple sensing functions was achieved through a single optical sensor on a flexible substrate while holding excellent contact with the body. SIGNIFICANCE: The sensor patch system can be used for fitness guidance, skin disease detection, and wound monitoring and management by replacing related sensitive films.