The University of North Carolina at Chapel Hill

Designers: Benjamin Smith, Erica Lee, Siroberto Scerbo
Client Coordinators: Allison Darwin OTR/L, Cindy Thompson RN, Carolina Meadows retirement facility

INTRODUCTION

EMOD is a custom pill dispenser designed to give people with disabilities independence when managing complicated pill schedules, while at the same time also reducing the risk of incorrect dosage organization and consumption. Primary objectives include creating a dependable device that is easy to use, dispenses variable medication doses, reminds clients of their medication schedules, safely halves necessary pills, and eliminates medication loading errors. The device also needs to be functional with the use of one arm, to be able to withstand tremors, and to require minimal strength during usage.

SUMMARY OF IMPACT

The EMOD allows our clients the ability to manage their complicated medication schedules with little or no help. They are easily able to load their own pills using the Pill Loader, which helps prevent errors in the setting up of their medication schedule. For cutting pills, there is no exposed blade for an individual to cut their finger on the Pill Cutter. Once the pills are loaded and the alarms are set, the pills will be dispensed at the appropriate times, and the individual will hear an audible reminder.

Figure 1: Front View of EMOD. The Pill Dispenser is on the right with its lid open. The Pill Loader and Pill Cutter are on top of the dispenser, and the mounting stand is on the left.

TECHNICAL DESCRIPTION

Overall operation:

The heart of the device is the Medtime XL motorized 28 compartment tray (made by Careousel, Sweden, and purchased from epill.com). The existing electronics were removed, and custom electronics as well as new mechanical features were added to make it accessible to people with disabilities. Fully automated, the user enters the time of day, and sets up to four alarms when medication needs to be taken. If pill cutting is necessary, the custom Pill Cutter is designed with safety guards and a sliding loading tray that protect the user from the sharp blade. Then the user loads the pills using the clear acrylic loading tray, which provides full visual and motor control over which pills go into each compartment of the pill dispenser tray. Once loaded, the dispenser is then placed upside down into the mounting stand. When an alarm goes off, EMOD automatically advances the dispenser to the next compartment, dumps the desired pills into a small cup, and gives an audible alert. The cup is replaced by the client after every dose. Appropriate placement of the cup is aided by a marked red area beneath the pill dispenser.

Pill Dispenser:

The pill dispenser has four operational modes: Loading, Set Current Time, Set Alarms and Run. The interface for the pill dispenser consists of 3 buttons, an LCD, LEDs and a switch to turn off the verbal commands. The left button cycles between the pill dispenser’s operational modes, the middle button changes the hours and the right button changes the minutes. The LCD displays the current operational mode and gives instructions to the user. For those users who have difficulty reading the LCD, the device also provides prerecorded verbal commands. The user can toggle a switch to turn those verbal commands on or off.

For loading and run modes, a DC motor advances the dispenser tray in a clockwise motion. There are tabs on the bottom of each compartment and an infrared detector and emitter will detect the passing of the tabs. When the tray advances to the next tab, the system stops the motor.

The custom circuitry consists of a PIC 16F877 microcontroller (Microchip, Inc., Chandler AZ) programmed in C-language, an ISD33120 voice recorder chip (Winbond, San Jose CA), an LM386 amplifier and a MAX232 driver.

Pill Loader

We developed a pill loading tray to facilitate the loading process. Since the user will typically take the same medication at a given time of day (morning, noon, evening, and bedtime), we designed this tray so that the user first loads all morning pills for the week. The upper loading tray has holes for every fourth compartment so that the user can load these pills in the appropriate places. Initially, the pills sit below the upper loading tray, but on top of the lower tray. This allows for easy correction of any loading mistakes. Once the user confirms that all of the pills are placed properly, then he or she slides a lever on the lower tray to drop them simultaneously into the compartments below. They repeat this process for all of the noon, evening, and bedtime pills.

The upper tray loader was constructed of 0.177” thick clear acrylic. Using a laser cutter, we cut seven large thumb-print sized holes, so that they would be placed over every fourth compartment of the pill dispenser. The lower tray loader was cut out using 0.08” clear acrylic but was modified to include an extra piece as a handle. To prevent pills from falling over the outer edge we used 0.177” thick white acrylic to create a ring barrier on the outermost edge of the top piece of the pill loader.

Pill Cutter

The blade guards and limited opening angle prevent the blade from being exposed. Using a stop bar we limited the opening angle, which prevents the blade from being exposed.

The total cost of project was $384.28.

Figure 2: The user is loading pills into every 4th compartment (corresponding to Sunday morning, Monday morning, etc.) using the Pill Loader trays.