Project Introduction:The objective of this team is to design a device that provides compressions to individuals requiring CPR during natural disasters, specifically those who do not live within a reasonable distance to a hospital. The device must be low-cost, portable, and effectively administer automated compressions to relieve first responders to prevent rescuers’ fatigue. The device will be able to provide compressions for up to an hour while the patient is in transit to a medical facility. Additionally, the device will be simple to use with user-documentation.
The automated CPR device is designed to be used by first responders in situations where CPR is necessary for long periods of time (Ex. An emergency occurring more than 45 minutes from a medical facility). Thus, the device must be small enough to be transported in a medical transportation vehicle, light enough to be carried for long distances, and usable while the patient is on a backboard. If the user is not trained in administering CPR there is a high risk that it will not be used properly and will lower the chances of a successful resuscitation. Therefore, the device should only be used by persons certified in administering CPR.  Since the device is meant to be able to be used during natural disasters, exposure to the elements is expected and the device must be durable enough to withstand them. One of the main requirements of the device is that it is low-cost. This means that the device is limited in usable materials and functionalities, but this should not hinder the ability of the device to administer automated compressions. Maintenance of the device needs to be easily done by medical faculty. There will need to be proper documentation to allow maintenance by medical faculty with varying technical expertise (at least the most vital functions). The device is expected to be stored in medical transportation vehicles. However, it must be regularly charged, and it should be regularly inspected for defects in the hardware.
Solution Description:The device power supply is a lithium-ion battery whose voltage is stepped down by a buck converter to achieve nominal voltage of the motor driver. The motor driver connects the power supply to an Arduino microcontroller and the motor itself. The driver code on the Arduino supports the use of a user interface to control the power to the motor and to keep the user updated with the device status (powered, running, errors). Errors are measured through a hall effect sensor measuring the compression rate and a temperature sensor tracks the ambient temperature of the device. The motor is connected to a gearbox via a coupler, and the gearbox is connected to a piston through machined parts that resemble a piston-crank mechanism. The piston is made to have a linear motion using a linear bearing which is located on the bottom side of the enclosure. Lastly, a fan acts as a cooling system for the device along with an exhaust located near the motor. The enclosure contains all the device components. A frame attaches to the legs of the device which attach to a backboard.