College - Author 1
College of Engineering
Department - Author 1
Biomedical Engineering Department
Degree Name - Author 1
BS in Biomedical Engineering
College - Author 2
College of Engineering
Department - Author 2
Biomedical Engineering Department
Degree - Author 2
BS in Biomedical Engineering
Date
3-2025
Primary Advisor
Michael Whitt, College of Engineering, Biomedical Engineering Department
Abstract/Summary
This document outlines the key steps taken in the specification, design, and functionality of the Tiny Temp Neonatal Intensive Care Unit Infant Temperature Monitor. The BICEP team identified temperature monitors for infants in incubators in the NICU as an area of need after surveying hospitals in the San Luis Obispo area. Current thermometers are oversimplified in design, consisting of only the temperature probe and a piece of adhesive holding the probe directly onto the infant's skin. As a result, the adhesive is weak to prevent harm to the infant and, therefore, falls off the infant easily and frequently, posing a high risk of falling off while in the incubator and therefore reading the incorrect temperature. The proposed solution is Tiny Temp, a temperature probe designed to be able to click in and out of place so that if the wires are pulled on, the probe will click out of place without removing the adhesive layer. This allows for a stronger adhesive to be used while not posing any additional risk to the infant. Key customer requirements and specifications were identified. Customer requirements were identified from interviewing project advisors Lance Hsu and Kaila Richards along with stakeholders CeeCee Curry and Dr. Van Scoy before the design process was underway. These requirements were made with both nurse and patient in mind. In the event that the temperature probe is tugged, the customer requires that the probe should click out of place before the adhesive rips off the baby’s skin. Additionally, if the cord is pulled on, the probe wire should remain intact so that the device is still functional once clicked back into place. Next, the temperature probe should be cheap and simple to use as well as small in size so that it can be a valid competitor for the current solution. Finally, the adhesive and probe used must be safe to use on an infant’s delicate skin, as to not compromise the biocompatibility of the device. After defining the customer requirements, the specifications were created to fulfill all key needs. In order to be competitive in the market, the ideal overall cost for the device is under $30, and the ideal size is equal to or smaller than 1 inch. Additionally, temperature should ideally be within +/- 0.54 degrees Fahrenheit, and the device should be able to be removed and replaced at least ten times before failure. To ensure the clicking mechanism works as planned, the force to dislodge the temperature sensor should be less than the force to dislodge the adhesive. The adhesive should also stay intact in the presence of bodily fluids, such as sweat and oil, and finally the device should be overall comfortable for the infant to use for long-term periods. After the customer requirements and specifications were determined, our team began the design process. The BICEP team had an initial concept for a design, which we modified off of to improve manufacturability, ease of use, and proper function. Based on their initial design, our team came up with a series of concepts that could possibly be used to build upon the design. After evaluating these concepts with a Pugh chart, we designed a new conceptual model incorporating the changes we believed gave the most improvement to the design. From there, we began manufacturing prototypes and making adjustments until a final prototype was reached. The piece was manufactured in four separate stages, including circuit wiring, making the aluminum insert, 3D printing the insulating layer and popping piece, and finally assembling the piece.
After the prototype was assembled, functionality was assessed in three major tests. The first was a peel test, in which various adhesives were compared based on their strength to dislodge. In this test, an Instron was used to perform t-peel tests of various adhesive samples to compare them based on their tensile strength. Based on the tests, we determined that DuoDerm would be the best option for our product, with an average T-peel adhesive strength of 0.391 N/mm. The second test performed was a force to dislodge test to determine the strength needed to pull the probe from the popping base at different angles. From this, we were able to determine that our prototype can successfully be pulled out of the popping base with less strength than is required for the adhesive to be dislodged. The final test was a temperature test, in which the Tiny Temp was compared to a standard temperature probe to compare temperature accuracy and efficiency. This test determined that our prototype is capable of measuring temperature with some margin of error. In addition, budget and device size were examined by comparing the size and theoretical cost of one Tiny Temp unit to AccuTemp, the current industry standard. This comparison found that Tiny Temp is a valid competitor as it is smaller in size and has a similar price to its competitor.
URL: https://digitalcommons.calpoly.edu/bmedsp/224