INDIGENOUS DEVELOPMENT OF A CLINICALLY SAFE, LOW COST MICROCONTROLLER-BASED BLOOD WARMER FOR RESOURCE LIMITED HEALTHCARE

Abstract

Blood transfusion is a critical medical procedure in trauma care, surgery, and obstetrics. However, transfusion cold-stored blood without proper warming can induce hypothermia, cardiac arrhythmias, and increase mortality rates, particularly in resource-limited healthcare environments such as rural Pakistan. In the present study, we design and fabricate an indigenous, low-cost, microcontroller-based blood warming system optimized for deployment in resource-limited medical settings. The device incorporates Positive Temperature Coefficient (PTC) ceramic heating elements, a servo-actuated shaking mechanism to ensure uniform heat distribution, thermocol insulation for thermal retention, and an MLX90614 infrared sensor for precise, non-contact temperature monitoring. A simple on-off control algorithm maintains stable and reliable temperature regulation at the clinical threshold of 37 °C, with an integrated buzzer and Liquid Crystal Display (LCD) interface providing real-time operational feedback and safety alerts. Bench-top in vitro tests demonstrated that the prototype effectively elevated a 500 mL blood bag from 4-6 °C to 37 °C within 12-14 minutes, achieving high accuracy (±0.4 °C) and uniform warming without inducing hemolysis, as confirm by plasma free hemoglobin analysis. Comparative evaluation against a laboratory water bath highlighted the device’s faster and more controlled heating profile. Cost analysis revealed a fabrication cost of approximately PKR 29,000 (˂ 100 USD), substantially lower than commercial alternatives. Thus, the developed system offers an affordable, safe, power efficient (~300 W), and ease of local fabrication, presenting a clinically viable and scalable solution for safe blood transfusion in emergency and resource-limited healthcare settings.