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 non-adherence. 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. 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. 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, non-adherence adds almost $100 billion to current hospital admissions. 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 1physicians 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. 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 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. 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. Figure 2a. A schematic representation of the switch matrix connected to the microcontroller. 2Figure 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 10KΩ and the larger Schottky diodes, not included in the switch matrix, are to prevent current from returning to the battery or the USB component. The software sends information to store on the microprocessor and receives the data when the doctor requires it. Two regular AA batteries would be used to power the
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