AutoRX

A new way of managing perscriptions

A capstone project for 24-671: Electromechanical Systems Design-Spring 2023

in conjunction with Jason Easterling, Li Fen Frothingham, Lana Hasher, Samyak Jain

Overview

    • From 2015 to 2018, almost 50% of Americans reported using at least one prescription drug in the last 30 days.

    • Almost 90% among those 65 and older, with approximately ⅔ of this age group took at least 3 prescriptions drugs in the last 30 days

    • Interviews with doctors revealed that compliance with prescriptions, especially for addiction patients is one of the largest difficulties

  • Keeping track of prescription schedules, especially when multiple prescriptions are involved. Patients can be forgetful, confuse pills, and keep old pills once prescriptions have been replaced.

  • We set out to design and manufacture a fully automated system that is able to scan QR codes on pill bottles, accepts the pills, and dispenses on the appropriate schedule.

  • A survey sent out to patients, doctors, and caregivers showed that the following are necessary components of the design:

    • The correct number of pills can be despenced

    • The dispenser can maintain an accurate inventory of pills contained inside

    • The dispenser can accurately dispense pills of different shapes and sizes

Pill Manipulation Mechanism Design

Decision Matrix:

After coming up with many different designs, we used a decision matrix to figure out which design(s) were worth pursuing through prototypes. Ultimately we landed on the vibratory bowl feeder.

Initial prototype

Our first attempt performed decently, but required some tuning. Notably, our resulting ideal frequency was within 2 hz of the natural frequency determined through simulation! We also were able to check off a few key objectives with this prototype:

  • The bowl feeder can be easily designed, constructed, and controlled

  • Different pills can be dispensed

  • Pills are dispensed one at a time

Sketching

We started out by sketching many different designs that could serve as dispense mechanisms. In particular, I looked into an iris concept, and a conveyor design. These initial sketches helped us understand and communicate ideas for further discussion.

Initial bowl feeder design

This is our initial design for the bowl feeder. It is comprised of a spiral bowl, electromagnet, base, and leaf springs. The magnet drives the bowl up and down, but due to the springs, the bowl also twists in the process. Adjustable springs allow for the modal shape to be adjusted. This combined periodic twisting and vertical motion is what drives the pills up the helical ramp, and organizes them single-file.

Pill counting

The final missing piece to the puzzle was ensuring that the quantity of pills dispensed was accurate. To close the loop on this quantity, we included a gate that involved two servos and a beam break sensor.

Other components

QR code sensor

This was an off the shelf component that could be controlled with an Arduino. I generated QR codes that contained information such as pill name, qty, and dosing information. This QR code would be printed on pill bottles for patients to scan before dumping the medication into the machine.

Pill bowl carrousel

The Bowls needed to be carried around. To accomplish this, we implemented a very simple carrousel that used a motor to move the bowls around on a rail. Each bowl was constrained underneath with bushings that ran on a rail. The metal disk drives them around.

Disconnected rail section

In order for the vibrational feeder system to work, the rail section above the electromagnet needed to be disconnected from the rest. At the same time, the bowl above the electromagnet needs to be locked to the moving rail section. This is accomplished with a solenoid in the center of the section, which transmits the vibrations from the electromagnet directly to the current bowl.

Pill divider

The last component needed is the pill divider, which directs the pills either towards the user cup, or the trash shute. This component has the added benefit of releasing all of the different pills at once, which prevents the user from prematurely grabbing the cup.