Senior design project could be a turning point for emergency intubations

MechSE seniors Anthony Bruno, Siyao Luan, Amit Madhukar, Shivani Parekh, and Rebecca Zabawa recently presented their ME 470 final design project, an improved intubation device. Intubation is a common way of re-establishing a person’s airway in emergency situations. EMTs do this on the scene or in an ambulance by sliding a tube into the patient’s trachea. Typically, an aluminum rod, called a stylet, is fixed inside the intubation tube to give it structure. The tube is inserted into the trachea and the stylet is removed. This needs to be done as quickly as possible.

“The procedure may seem simple and reliable, but actually it’s not,” said the students. “Since the opening of the esophagus is just behind the opening of the trachea, the intubation tube often goes into the esophagus. There is considerable trauma when the stomach is intubated instead of the lung.” 

Their proposed solution is an intubation device that tells the EMT whether the tube is in the trachea or the esophagus. Their prototype includes a circuit (designed by the team) plus a stylet with permanent magnets attached to the end, and a servo attached to the stylet. A servo is a small electric motor that, when activated, rotates a set number of degrees and stops at that point.

To start the process, a sensor is placed on the patient’s Adam’s apple. The voltage output on the sensor increases as the distance between it and the magnets decreases. The prototype’s system is set so that when a certain voltage threshold is reached, a green LED indicator light turns on. The light remains lit as long as the magnets are in the correct range. If the threshold isn’t reached, a red LED comes on, indicating that the stylet has gone into the esophagus instead of the trachea. At that point, instead of pulling the tube all the way out, re-bending the stylet, and re-inserting the tube, as is done now, the EMT only has to retract the tube part way so that the stylet is out of the esophagus. Then the servo can be turned on, causing the stylet to be bent toward the trachea and allowing the tube to be fully reinserted. The EMT can further verify correct placement by using the included carbon dioxide sensor. 

The team, whose faculty advisor was MechSE professor Harley Johnson, worked with Carle Foundation Hospital and received funding from Shell Corporation. They tested their prototype on two different anatomically correct models and saw an 88 percent accuracy rate of correct placement in the trachea in less than two minutes.

“Our improved intubation device offers an additional degree of control, consistency in placement verification, and remarkable accuracy of placement. With this device, there is a better chance that a person can be intubated properly in time and thus be saved,” said the students.