The trend toward miniaturization and multi-functionalization of implantable medical devices is shifting the paradigm of medicine from treatment to prevention and precision management; however, it faces a bottleneck due to the energy density limits of batteries. Existing power transfer technologies based on electromagnetic induction or radio frequency cause rapid efficiency degradation and electromagnetic interference issues in micro-scale devices. This paper reviews laser-based optical wireless power transfer technology as an innovative alternative to these issues, with particular emphasis on its potential medical applications. We provide an in-depth analysis of strategies to maximize penetration depth using near-infrared windows and light propagation characteristics within biological tissue, optimization of conversion efficiency through bandgap engineering of silicon (Si) and gallium arsenide (GaAs) based photovoltaic cells, and the latest wavefront shaping and optical phased array technologies to overcome dynamic scattering. Furthermore, by chronologically organizing research trends over the past 20 years, we discuss the paradigm shift from passive devices to active intelligent systems and present the technical and regulatory challenges for clinical adoption based on international safety standards (IEC 60825-1, ISO 14708-1), ultimately providing a technical roadmap for the energy autonomy of next-generation bio-electronic medicine.

PURPOSE: We aimed to investigate the appropriateness of transport of children via emergency medical service providers (EMSP) according to the decision-maker on referred hospitals (EMSP [EMSP group] vs. guardians [user group]). METHODS: We analyzed first aid records by EMSP for children aged 15 years or younger in Gyeonggi province, Korea, from January 2012 through December 2013. We obtained the following data: scene, symptom, type (high-level [regional/local emergency medical centers] or not) and location (out-of-province or not) of referred hospitals, injury, level of consciousness (alert or not), and prehospital triage results by EMSP (emergent/less emergent or not). RESULTS: A total of 50,407 children were included, of whom 37,626 (74.6%) belonged to the user group. Overall, the most common scene, symptom, and type and location of referred hospitals were home (57.0%), pain (33.3%), and inside-theprovince and local emergency medical centers (44.2%), respectively. The user group showed less frequent injury (P < 0.001), decreased level of consciousness (P < 0.001), and no significant difference in the triage results (P = 0.074). This group showed more frequent transport to high-level and out-of-province emergency medical centers (P < 0.001), and longer transport (P < 0.001). CONCLUSION: The user group showed more frequent transport to high-level or remote referred hospitals without more critical prehospital triage results. Guardian-directed transport of children might be associated with the inappropriate transport of children via EMSP.
Ambulances ; Child* ; Consciousness ; Emergencies* ; Emergency Medical Services* ; Epidemiology ; First Aid ; Gyeonggi-do ; Humans ; Korea ; Transportation of Patients ; Triage