Embedded Medical Monitoring Systems Designed for Intermittent Power and Connectivity in Crisis-Affected Healthcare Facilities A Review with a Case Study from Yemen

Nearly half of Yemen's health facilities are currently partially operational or fully out of service, and unreliable power supply is one of the most consistently cited causes. The World Health Organization has supplied more than seven million litres of emergency diesel fuel annually to over 100 Yemeni hospitals, a stopgap that only partially meets demand, while clinical staff report that a single brief power outage can cost a patient's life in electricity-dependent departments such as laboratories, blood banks, and neonatal care. This review examines the engineering literature on embedded medical device design for low-resource and power-constrained settings - the field known as frugal biodesign - and argues that monitoring devices for such environments must be designed around intermittent power and connectivity from the outset, not adapted afterward. It surveys recent embedded, microcontroller-based device designs validated for low-resource clinical use, examines solar-retrofit case studies from Yemeni hospitals, and sets out design requirements - battery-buffered low-power operation, offline data logging, and field-level repairability - specific to this operating environment.