A) Clip Monitor for WHO's packaged medication.
The Global Drug Facility at the World Health Organization assists in the distribution of packaged fixed dose combinations of TB medications (WHO's packaged medication). These preparations are given anywhere from two to five pills each day depending on the patient's weight.
A medication monitor designed to dispense strips of blister-packaged medication where each strip contains the proper number of individually packaged medication units for the prescribed drug regimen is described here: The medication monitor shown in Figure 1 employs an array of clips in which each clip holds one strip of blister-packaged medication. Each clip is located between the first and second package of each strip so it can hold a short strip of two packages or longer strips, for example three, four, or five packages. This device records the time when patients remove strips of blister-packaged medication from a container of medication.
The device includes covers to keep out dirt and water and to keep the strips in place if the device is dropped or subject to severe jarring.
To make it possible for the device to hold a month's supply of medication and keep the device as compact as possible, the underside of the device contains the same array of packages, clips and cover as the upper side.
The clips, which hold the strips of packaged medication, are made of electrically conductive material and serve the additional function of detecting when medication is removed. Each group of 14 clips, 7 above the circuit board and 7 below, is assembled into a carrier block which protects the spring clips from mechanical damage and facilitates handling of the clips during manufacturing. The two sides of each clip are connected to an electronic unit with traces that lead from the clip to the electronic unit. The electronic unit periodically connects each clip into a circuit to sense electrical continuity through the clip. If a strip of packages is being held in a clip, electricity will not pass, but when the strip is removed the electricity will pass. If the electricity fails to pass at a first point in time, like 10:00 AM, and passes at a second point in time, like 10:05 AM, this demonstrates that the package was removed between these two times.
In the design illustrated, there are a pair of switches each of which detects opening of one of the covers which protect the medication. When either of the covers is opened, an LED is illuminated to instruct the patient whether he should remove and ingest medication, green if medication is to be taken or red if medication is not to be taken. The LED is also used by the caregiver to retrieve the patient’s adherence record and battery condition, as described in the simple red/green LED section in the portion of this site devoted to displays.
The button which the caregiver uses to instruct the microcontroller to present the battery status and adherence displays is located behind a separate cover. In the design illustrated, this cover can only be opened when both medication covers are opened. Figure 2 shows the opened caregiver access cover. Opening this cover also provides access to the batteries permitting the caregiver or clinic worker to replace the batteries.
The Caregiver cover also provides access to a connector on the circuit board by which an external computer or PDA can be connected to download the adherence record. A spring contact inside the caregiver cover connects two of the contacts on this connector when the caregiver cover is closed and disconnects them when the caregiver cover is opened. This spring contact, then, acts as a switch to signal opening of the caregiver cover.
There is a possibility that some patients might insert empty strips of medication packages or other items into clips from which medication had been removed. It is necessary to avoid recording subsequent removal of these items as medication removal, as discussed in the simple red/green LED section. The problem of dealing with emptied clips into which items have been inserted can be avoided if the clips are designed to prevent the patient from inserting items into them, as illustrated in Figure 3. With this design, a special tool is required for filling the monitor in the clinic, also shown in Figure 3.
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POTENTIAL AND EXISTING MEDICATION MONITOR DESIGNS
I. Cover and Cap Opening Monitors
II. Dose Removal Monitors
A) Clip Monitor for WHO's packaged medication.
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