Extending patient simulation: a novel prototype to produce tympanic thermal output

Despite technologic advances in task trainers and manikins, there persists an inability to replicate key clinical skills as would occur in clinical settings. This report provides details of a project to develop a functional and reliable tympanic thermal simulator prototype that could be embedded into the ear of a manikin to enable tympanic thermometers to be used during simulation encounters.

A simple electrical circuit was built using (i) a standard 9-V battery, (ii) a switch, (iii) 5 × 62-Ω resistors in parallel for circuit stability, (iv) a 62-Ω resistor in parallel with (v) a 1-kΩ potentiometer to vary the infrared light-emitting diode (IRLED) intensity, and (vi) 2 IRLEDs. After confirming reliability of circuit performance, the IRLEDs were implanted into the ear of a manikin. Over 3 consecutive days, 3033 samples were recorded simulating a range of human body temperatures, controlled by altering current flow.

Initial testing of the thermal simulator prototype indicates that a range of human temperatures (34.0°C-41.9°C) can be generated using high-intensity IRLEDs. Although, at higher applied current levels, the variation in measured temperature was larger (2.4°C) than at lower applied currents (0.2°C), reasonably precise temperatures were achieved.

Testing and reporting initial prototype results are an important first step in developing and refining a useful product to enhance manikin capabilities associated with patient physical assessment in the simulation setting. Despite the undesired variation, the current design could still be used for teaching purposes in educational settings. Retrieving tympanic temperatures during "patient assessment" of the simulator benefits nursing, midwifery, and other health care students by enabling authentic practice. Further development of this prototype is required to improve the reliability, precision, and accuracy of the device.