Using Technology to Measure Adherence of Complicated Medication Regimens N YAMDAGNI S BHAHEETHARAN C DUNN AND F FAHIMI University of Wisconsin Madison Department of Biomedical Engineering Wisconsin 53706 USA ABSTRACT Seventy five percent of all patients do not take their medications according to their doctors prescriptions Dr Timothy Juergens a geriatric psychiatrist and sleep specialist at the University of Wisconsin Madison Hospital and Veterans Affairs Hospital requested a method of determining causes of nonadherence To fulfill these needs the Electronic Medication Adherence Device EMAD was designed The EMAD consists of a standard 7 x 4 compartment pillbox and a complex circuit with a PIC18F4550 microcontroller that is capable of monitoring when each compartment is opened Additionally the date and time of these opening are stored and can be accessed by the physician with a computer using Microsoft Excel To remind patients to take their medications a piezoelectric buzzer acts as an alarm Tests were conducted to verify the functionality of the EMAD s ability to record a single button transmit patient data and log time and date accurately Test results indicate that the EMAD is able to complete these tasks successfully However the switch matrix connections have an unknown fault which will require troubleshooting A completed EMAD will enable Dr Juergens to identify reasons for medication non compliance as well as promote adherence This severe failure to follow doctor prescribed medications is a significant cause of illness in these individuals Clearly a medication is unable to work unless it is taken correctly by the patient This inability to adhere to medications causes numerous deaths each year Osterberg Blaschke 2005 According to an article in The New England Journal of Medicine nonadherence adds almost 100 billion to current hospital admissions INTRODUCTION An important problem in today s medical world is the significant failure to follow prescribed medication regimens This is specifically true for the elderly Often these users take medications multiple times throughout the day Most patients do not comply with their medication regimen Reasons for this may include forgetting to take the medication or refusal to take a prescribed dosage Regardless of the reasons only 1 in 4 patients take his or her medications correctly Osterberg Blaschke 2005 Our client Dr Timothy Juergens is interested in determining the cause of this non adherence by recording pill access times Furthermore he has presented this case to promote adherence among geriatric patients To avoid being seen as a bad patient by their physician people often lie to their doctor about their medication compliance This has an adverse affect on both the patient and physician In order to better understand the long term results of non compliance a pillbox was constructed to record removal of prescribed pills By recording such information it is hopeful that 1 physicians will be able to target the root causes of non compliance The appliance Electronic Medication Adherence Device EMAD is safe for home use and provides physicians with vital information regarding when medications are taken by patients METHODS Pillbox The pillbox layout suggested to us by our VA contact requires the use of a 7x4 design This design allows the user to separate 4 medication regimens per day for morning noon evening and bedtime The switches that were installed were single pole double throw Submini Roller Lever Switch 275 017A The installation is designed to create a reliable activation of the switch each time the lid is opened for more than one second In each compartment a small Plexiglas plate is used to separate the medications from the switches to avoid contamination Circuit In order to accurately record the time and date of each compartment opening a switch matrix is required to process all voltage differences caused by switch activations The circuit consists of a few key components including the microprocessor watch chip and the Universal Serial Bus USB converter The circuit acts as a communication link between the pillbox and the software made entirely from Visual Basic Each component serves a specific purpose to relay information to the user Ribbon cables are used to attach the independent switches from each compartment to the circuit board The circuit board is designed to direct the current to its appropriate position on the switch matrix Each cell on the matrix consists of a switch and diode 1N4148 to ensure current flows away from the switch towards the microprocessor inputs This can be seen in Figures 2a and 2b To improve the aesthetic quality of EMAD a wooden box was created to enclose all circuitry Open circuitry can cause intimidation and possibly lead to failure of the prescribed regimen The hidden circuitry still allows access to the computer s USB port In order to provide circuit maintenance the circuit board can be accessed by removal of the pillbox see figure 1 Figure 2a A schematic representation of the switch matrix connected to the microcontroller Figure 1 Electronic Medication Adherence Device EMAD a pillbox with a circuit to monitor the opening of the compartments The circuit is held within the wooden box to ensure the patient is not apprehensive about using the box 2 was a crucial element in the setup because it converted the electronic serial data into usable USB information Thus clinicians can plug the pillbox into any computer with a USB port The converter is connected directly to the microprocessor in addition to the 5 volts and ground ports Normally an LPT port would have to be utilized without this converter making accessibility very difficult Figure 2b The completed PC board design with all circuit components The switch matrix consists of 7 columns and 4 rows However one can also recognize this setup as 4 inputs and 7 outputs Each input would normally require a pull up resistor to separate voltage values Fortunately the Microchip PIC18F4550 has this functionality built in and must be activated by the BASIC code This helps minimize the weight of the circuit and reduce cost The microprocessor shown with a pink outline in Figure 2b connects all of the circuit elements together It communicates with the watch chip the USB converter the entire switch matrix and the alarm Every resistor seen on the circuit is 10K and the larger Schottky diodes not included in the switch matrix are to prevent current from returning to the battery
View Full Document
Unlocking...