Overview

The final design utilizes a stepper motor with a lead screw held within a frame as a means to control the syringe in injecting and extracting. A syringe adaptor attached to the lead screw will hold the plunger of the syringe while the frame itself will hold the flange of the syringe, controlling the syringe. A stepper driver and microcontroller will be used to control the motion of the rotation of the motor, all powered through a 24 volt 2 amp wall power supply with a 9 volt regulator allowing safe powering of the microcontroller. A three position switch will allow the user to control the direction of the movement of the syringe adaptor, while a two position switch will the on-off power of the entire design. Lastly, two limit switches are placed to stop the movement of the syringe adaptor when the syringe is either fully pulled back or out of liquid.

Key Components

Overall Device Cost

Summary of Performance

Overall, the device was successful in achieving the project objectives, but there could have been further improvements for cost reduction. The desired operation time of the device needed to be under ten minutes to be an improvement to the current operation time when performed by hand. A flow rate of 1.33 cc per second correlates to an operation time of exactly ten minutes so any flow rate higher than this is acceptable. The device prototype was tested to ensure this requirement was met and the results showed it is able to provide a flow rate of 2 cc per second. This flow rate translates to an operation time of 6.67 minutes which is a major improvement to the previous time. While the device operation was successful, the cost of the frame could have been further reduced if less custom components were utilized. They could be replaced with more widely available stock items, but the custom components used did improve the overall efficiency of the device and give it a more polished finish for patient comfort. 

Videos of Final Design