Mechatronics Application for a Smart Inhaler

Metered dose inhalers (MDI) are used to manage or to provide quick relief to asthmatics. The improper use of an inhaler can result in the administration of an incorrect medication dosage, reducing the effectiveness of the device and resulting in higher treatment costs for the patient. The design process of an inhaler sleeve is outlined, intended to assist in the use of a standard MDI. The purpose of the sleeve is to monitor the user's technique during the four most critical steps of their inhaler use. These steps include shaking the device before use, coordinating the canister actuation with their inhalation, inhaling at the correct rate, and holding their breathing for the correct amount of time. The final design consists of a 3-D printed sleeve and a mobile application that guide the patient through the process. Lights are integrated into the sleeve indicating to the user which step they are on and for how long. Sensors are able to monitor the inhaler throughout its use and provide feedback by sharing the data collected to a mobile app. From there, users are shown what steps they are preforming correctly, and which ones need further improvement. A prototype printed in polylactic acid (PLA) acts as a reference for the accuracy of the 3-D model created. A finite element analysis conducted on the model indicates that the PLA material has sufficient strength for the product; however, opting to print in polyethylene terephthalate glycol (PETG) will allow the inhaler to fit into the sleeve more easily and will reduce the concentrated stresses and deformations seen on the sleeve.