Study on method to simulate light propagation on tissue with characteristics of radial-beam LED based on Monte-Carlo method

Towards Self-Powered WSN: The Design of Ultra-Low-Power Wireless Sensor Transmission Unit Based on Indoor Solar Energy Harvester

The current revolution in communication and information technology is facilitating the Internet of Things (IoT) infrastructure. Wireless Sensor Networks (WSN) are a broad category of IoT applications. However, power management in WSN poses a significant challenge when the WSN is required to operate for a long duration without the presence of a consistent power source. In this paper, we develop a batteryless, ultra-low-power Wireless Sensor Transmission Unit (WSTx) depending on the solar-energy harvester and LoRa technology. We investigate the feasibility of harvesting ambient indoor light using polycrystalline photovoltaic (PV) cells with a maximum power of 1.4 mW. The study provides comprehensive power management design details and a description of the anticipated challenges. The measured power consumption of the developed WSTx was 0.02109 mW during the sleep mode and 11.1 mW during the operation mode. The harvesting system can harvest energy up to 1.2 mW per second, where the harvested energy can power the WSTx for six hours with a maximum power efficiency of 85.714%.

Method for estimation of structural composition of skin layers based on light propagation simulation for liposuction applications

Skin surface irregularity is the most common side effect after liposuction. To reduce this, it is necessary to devise a systematic method to provide structural composition details of skin layers, such as fat thickness and fat boundary tilt angle, for the plastic surgeon. Several commercial portable devices are available to measure skin layer information, working on the principle of a near-infrared technique using the light penetration properties of tissue in optical windows. However, these can only measure general fat thickness and not the structural compositions of skin layers with irregularities. Therefore, our goal in this paper is to propose a method to estimate the structural compositions of skin layers by analyzing and validating the relationship between light distribution and structural composition from simulation data based on specific structural conditions.