A prototype device for thermo-hygrometric assessment of neonatal incubators

Beside other Clinical Engineering activities to reduce risks in hospitals, functional assessment of medical devices is becoming more and more extended. Once evaluated the common risk such those electric and mechanical, specific risk are connected to the device performance: functional assessment aims to verify the specific proper operations of a medical apparatus. In particular, neonatal incubators have the primary aim to maintain an adequate microclimate for the newborn, especially those premature and smaller, who may not be able to regulates body temperature. To prevent newborn heat loss, incubator mainly stabilizes the temperature of the baby compartment to a selected value, reducing the risk of hypothermia. As suggested by the Particular Standards for safety of baby incubators, temperature have to be measured in 5 specific points inside infant chamber: the difference between measured temperatures and that selected on incubator must be limited to fractions of °C. Also the time needed to reach a given temperature must be limited. Other tests should be performed to verify humidity, air velocity, noise level, CO2 concentration, etc.. A prototype device was developed to automatically perform functional assessment of neonatal incubators. A microcontroller continuously performs a 12-bit analog to digital conversion of voltage signals generated by 5 thermal probes and a humidity sensor and sends those data to a PC, where a software process received signal and provide tests. The HW device is of little dimensions, battery powered and capable to continuously transmit data wirelessly, the SW allows real-time signal display, average values, optic and acoustic alarms for limits exceeding, data storage, etc. The device can be easily used to perform periodical functional tests on neonatal incubators. Further analysis of recorded data can be used to evaluate more specific features such as modalities of temperature control, etc