(H-309) Pulse Oximeter Device for Simulation Mannequins

Introduction:: Simulation mannequins are used extensively (80% of medical schools and 87% of nursing schools)1 in healthcare education to create realistic clinical scenarios that allow students to practice their skills in a risk-free environment. Today’s mannequins are equipped with many intricate features; however, there is still room for improvement. For example, simulation mannequins lack realistic measurement of vital signs such as pulse rate and oxygen saturation (SpO₂) and this feature needs to be embedded in mannequins since abnormal readings in these vital signs could be fatal.

Currently, there are 2 methods in use in mannequin-based simulation-laboratories to measure pulse rate and SpO₂ levels: (i) in mannequins that have the capability to reflect physiological measurements, pre-set values are displayed on a monitor (Figure 1); (ii) in others, students during simulation use a regular pulse oximeter to mimic the action of clipping it to a finger and the instructor announces the measurements. Neither of these techniques are realistic. Furthermore, these options don’t respond to real-time interventions.

Therefore, this project aims to create a realistic stand-alone pulse oximeter device that can be integrated into any simulation mannequin. The purpose of the device is to train nursing students to measure vital signs (SpO₂ and pulse rate) and determine appropriate medical intervention in a risk-free environment. The specific aims are: (i) the device should have the ability to reflect normal measurements and disease conditions based on the clinical situation the instructor is simulating; (ii) the device should respond to real-time intervention from nursing students during simulation.

Materials and Methods:: To achieve the objective the following design criteria needed to be met: the device needed to

1. resemble a pulse oximeter both visually and operationally;


2. be able to reflect both normal and abnormal pulse rate and SPO₂ levels;


3. reflect change in pulse rate and SPO₂ levels based on nursing students’ interventions;


4. be affordable;


5. be able interchanged between different mannequin's fingers;


6. be easy to set-up by the instructor and easy to use for the nursing students;


7. be safe to use and abide by the FDA guidelines for Class II devices.

Based on these criteria an app-Controlled Bluetooth-based Pulse Oximeter device was developed. The device consisted of a 3D printed finger-clip casing that mimics the appearance of an alligator clip pulse oximeter and houses all the electronic components. The device operates via an Arduino Nano 33 BLE microcontroller board that has an embedded wireless Bluetooth receiver, an LED light, a force transducer, and an OLED display. The Bluetooth receiver obtains pulse rate and SpO₂ values transmitted from an app designed using MIT App Inventor. The LED light underneath the top surface of the case mimics the light source of an actual pulse oximeter. The force transducer placed on the inner surface of the case is activated when the device is clipped onto a finger which allows the values transmitted via Bluetooth to be shown on the OLED display. The case contains a push button switch to turn the device on or off.

Results, Conclusions, and Discussions:: The final product (Figure 4) meets all design criteria. The cost to develop the device is < $65 which makes it affordable. The 3D printed casing visually replicates the appearance of a pulse oximeter, thereby making it look and feel realistic. The device is easy to use both at the nursing students' and instructor’s end. During simulation nursing students clip the device on a mannequin’s finger which activates the force transducer and reflects the pre-set (by the instructor) values on the screen. This operation is similar to an actual alligator-clip pulse oximeter which enhances realism of the simulation experience. To set it up the instructor presses the smart connect button on the app to establish the Bluetooth connection. Once established, the instructor can set any pulse rate and SpO₂ values by using the sliders on the app. When required values are set the instructor hits the submit button to send the information to the device. As mentioned before, the measurements are displayed when the students turn on and clip the device on a finger. The instructor is capable of editing the measurement values during the progress of the simulation and hit the submit button to update the values based on nursing students’ actions; for example, if students administer a drug the effects on the measurement values can be changed by the instructor instantaneously. This real-time feedback allows nursing students to evaluate and analyze their intervention plan and make changes if necessary. The device is designed to encase all electronic circuitry and the battery inside a 3D-printed case to ensure safety. The device is interchangeable on any mannequin’s finger irrespective of make or model, as all it needs to activate the display is pressure on the force transducer.

A survey (Figure 5) administered to both nursing students and instructors demonstrates the usefulness of the device. Lastly, the device has an additional functionality. It has the capability to be used not only on mannequins but also on human beings. This is important since certain simulations use live action scenarios wherein instructors employ “actors” to impersonate patients for training (example: disaster simulations).

Acknowledgements (Optional): : The authors would like to thank Widener University’s School of Nursing for allowing us access to their simulation lab and providing us with feedback. We would also like to thank our Lab Engineer Christopher Hallahan, and Lab Technician David Leuter.

References (Optional): : 1. Vyas, D., Am. J. Pharm. Educ. 2013, 77(3), 53-53.