Medicament Dispensation System with Patient Supervision

Piotr Krasi ski, Krzysztof Kowalczy ski, Bartosz P kos awski, Andrzej NapieralskiDepartment of Microelectronics and Computer Science

Lodz University of TechnologyLodz, Poland

pkrasik@dmcs.pl

Abstract—In this article a safe and affordable system ofmedicaments dispensation is described. The system can beutilized in both hospital and home environments. The mainpurpose of the device is medicament dispensation accordingly todoctor prescriptions. As a first element of the system a safemedicament dispenser prototype was built. The device isdesigned to fulfill the needs of patients forced to take drugsaccordingly to prescribed scheme. Innovative safety featuresinclude a built-in GSM module. This feature ensure that apatient has taken the medicaments and in case of lack of patientreaction alarms a supervisor. A system to avoid therapy errorscan also be applied.

Index Terms—Medical electronics, medicament dispensation,patient supervision, safety functions, not self-reliant persons

I. INTRODUCTION

Nowadays, many people are forced to take versatilemedicaments. Delivering a proper dose at certain time iscrucial in many therapies [1, 2]. Moreover, people forced totake those medicaments are often handicapped. As a result,medicaments are not taken accordingly to doctorsprescriptions and the therapy is not effective. To control thetherapy, patients may be held in hospitals or must beconstantly observed by supervisors. Both these situations havestrong drawbacks. Patients are not only put under stress,because of hospitalization or constant supervision, but alsoboth solutions generates significant costs. Hospital staffmistakes are also not to be forgotten.

The effectiveness of therapy may be enhanced by leavingthe patient with more freedom and in the meantime ensuringproper therapy execution. Cured person may lead a normallife and a specially designed system may play the role of thesupervisor [1].

II. CURRENT SOLUTIONS

As far as hospitalization is concerned, some solutions ofautomated medicament dispensation were developed. Infusionpumps are utilized in some situations for patients tied to bed.Nevertheless, because of their complexity cost of their usageis significant. Moreover, application fields are limited. Forpatients who are able to move freely and are sufficiently

conscious infusion pumps are not necessary or not applicable.A simpler and cheaper solution can be found.

Most of the currently available solutions, for averagepatients, base on simple boxes with chambers anddescriptions. Medicaments are loaded to chambers labelledwith a date and hour. Such a device will not remind thepatient about the incoming time of medicament application.More advanced devices are featured with a kind of alarmclock that can be programmed to remind the patient to takethe pills. Nevertheless, none of those ensures that the patienthas really taken the pills. He or she may not hear the sound orare not willing to take the medicaments and brake the therapyschedule. To make things worse, none of the availablesolutions does allow the doctor or supervisor to control theapplied doses of medicaments [3].

III. THE PATIENT SUPERVISION

It is vital to ensure, the medicaments were taken by thepatient. The lack of his or her reaction may be a sign of apossibly serious problem:

patients health condition worsened and is not able topick up the medicaments,patient is away from the dispenser,patient is not willing to take the medicaments,device is malfunctioning or was not handledproperly.

In most serious situation the patient may require urgentmedical reaction. If the dispenser recognizes a possiblydangerous situation a text message is sent to the supervisor ofthe patient to make him or her aware of the situation. This isachieved thanks to the built-in GSM module. Anotheradvantage of this feature is the possibility of establishing avoice connection between the patient and supervisor. Thedispenser may automatically accept the call from trustednumber and make a conversation possible even in a situationwhen the patient is not able to approach the device.

The device can communicate with different persons withcustomized messages. Family member or doctor can bealarmed about the lack of patient reaction and local pharmacycan receive automatic order if the dispenser runs out ofmedicaments.

MIXED DESIGN MIXDES 2013, 20th International Conference "Mixed Design of Integrated Circuits and Systems", June 20-22, 2013, Gdynia, Poland

IV. THE THERAPY SUPERVISION

A priority of the medicament dispensation system is toensure an error-free therapy. To achieve this, not only thepatient is supervised but also the therapy itself may bereviewed. If the medicament dispensation unit would beconnected to the network, the programmed therapy could beverified in the central database [4]. Obviously, each patientand each therapy is different and suited to the certain situation,nevertheless some constraints are constant [5]. For example,maximum (lethal) doses of medicaments are known and if ahigher medicament dose is programmed to the device an alarmcan be signalled. The wrong dose may not necessarily becaused by wrong therapy scheme but be simple mistake duringdispenser programming.

The Anatomical Therapeutic Chemical (ATC)Classification System is a database of known drugs, controlledby World Health Organization Collaborating Centre. ATCcodes of the substances may be used in the therapysupervision system to integrate it with other existing anddeveloped systems.

V. SYSTEM PROTOTYPE

To demonstrate the described safe medicamentdispensation system a prototype device was built. It iscomprised of a medicament dispenser unit featured with aGSM module.

User interface comprises of a drum, tray and signallingdevices. The pills or other solid state medicaments are loadedto the drum chambers. Delivery times are programmed. If thetime comes, the drum rotates and pills from one chamber areplaced on the tray. The device starts to emit sound and visualsignals to remind the patient about the medicaments. Thesignals were selected with a regard on handicapped personswith limited sight or hearing. If the medicaments are notpicked up in a defined time period, the dispenser sends a textmessage to the supervisor and further actions can be taken.

Different therapy schemes can be applied. Date and hourof the medicament delivery are programmed on the user panel.Multiple deliveries per day are possible at any programmedtime. Day schedule can be repeated in the following days or adifferent scheme can be applied.

VI. SAFETY FEATURES

Because the dispenser may have indirect influence onhealth of its user, several safety measures were taken. Mostinnovative include a built-in GSM module. Its main functionis to alarm the supervisor of the patient in following situations:

Medicaments were not collectedAll medicaments were collectedAlarm button was pressedSelf-check procedure failed

Moreover, the device allows to establish a voicecommunication between the patient and the supervisor. Ithappens in two situations. Either the devices is called fromoutside or the supervisor is called after the SOS button waspressed.

The device is featured with a back-up power supply. Thetherapy schedule is retained even in case of prolonged lack ofmain power source.

Visual and audible signals were selected with a regard onhandicapped persons. Green backlight colour was selectedconsidering human eye sensitivity spectrum. The body of thedispenser is made of transparent plastic and therefore works asa big light source.

The body of the device is very robust. It must not onlysustain shocks and rough handling but also can be subjected topurposeful damage. In some situations it is highly possiblethat the patient will want to modify the dispensation schedule.

Attempts to block the drum can be done or the user can try torotate the drum manually. The methods to register this type ofmisuse are described in paragraph IX.

VII. THE CONSTRUCTION

The body of the prototype of the safe medicamentdispenser is made of transparent acrylic glass. It was not onlypicked with aesthetics in mind but in functionality. Speciallydesigned backlighting is activated to signal the medicamentpick up time. The whole body functions as a signalling lightvisible even for persons with reduced sight.

The hart of the device is AVR Atmega microcontroller. Itis responsible for therapy program starage, user interface andsensors handling and motor driving. All control devices,featured in the prototype, can be easily operated by persons ofwide age range. The size of the buttons and the four linedisplay were selected with handicapped persons capabilities inmind.

Infra-red light barrier is installed is the medicamentdelivery tray. If the light barrier is broken the assumption ismade, that the pills were collected. The most importantinformation, braking the light barrier delivers, is that thepatient is still alive and able to perform basic movements. Toenhance the accuracy of the test the weight of themedicaments can be measured. It can be assumed that the pillswere collected if their weight seized.

VIII. APPLICATION FIELDS

The described in this article safe medicament dispensationsystem can be utilized in both professional and homeapplications. In this case, as professional, we mean use inhospitals and other health centres.

Safe medicament dispenser with patient supervision wasdeveloped with handicapped, solitary persons in mind. It isespecially useful for persons living alone, who requireconstant supervision. It may reduce the time devoted byfamily or hired supervisors to patient. It can also reducepatients stress, by allowing him of her more self-reliance.

The dispenser can also be used in hospitals where onedevice can be assigned to one bed. As a result, nursesresponsibilities can be reduced. Moreover, the dispenser mayplay a very useful role for private use by average, self-reliantpersons who sometimes forgets about the therapy.

IX. FUTURE DEVELOPMENTS

In the prototype, main body of the dispenser and thecontrol device were housed in separated casings with wireconnection. In the final device, control electronics and userpanel can be integrated with device base. Moreover, furtherresearch can be performed on developing the interface to makeit most possibly suitable for elderly and handicapped persons.

The dispenser can be featured with an accelerometer. It candeliver an information about dispenser shocks. This can havetwo causes. Either the device was accidentally dropped andrequires revision or it was purposely destroyed by patient whorefuses to subordinate to prescribed therapy. In both casessupervisors reaction is required.

Another important component, not included in theprototype, is encoder, which can be used for monitoring of thedrum rotation. Thanks to it, any malfunction of the motor orgear transmission can be noticed and alarmed. Mechanicalproblems can be caused by misuse or purposeful act. If theuser would want to rotate the drum manually it would also benoticed by the encoder. To protect the drum contents fromunauthorised interference a lock can be featured. In currentsolution, the drum is opened by a convenient knob located inits centre. In a commercially manufactured a knob equippedwith a lock can be installed. The key to the drum can be own

Figure 3. Medicament dispenser main unit

Figure 4. Dispenser programmer

only by the supervisor. To avoid the risk of losing orforgetting the key it would be possible to use a lock operatedby a code. To input the code the dispenser keypad could beused.

In the prototype the fact, that the medicaments werecollected is tested by a infra red light barrier. This solutionsuccessfully verifies patient consciousness, however can becheated by leaving the pills on the tray. To resolve thisproblem and enhance the reliability of the test the weight ofthe medicaments can be monitored. If the pills were collected,the weight would be reduced. By application of advancedalgorithms it would be possible to protect the verificationprocess from cheating by loading other objects on the scales.

X. CONCLUSIONS

The main purpose of the safe medicament dispenser withpatient supervision is enhancement of the effectiveness of themedicament therapy and reduction of time and cost devotedfor patient care. The patient is not only reminded of themedicament taking time but also the device confirms themedicaments were collected.

The prototype of the safe medicament dispenser was builtand tested in target environment. It was used by patients ofone of the health centres in ód . Initial tests have proved thatthe device fulfils initial requirements. During the developingand testing procedures a few possible enhancements wereobserved. They were described in previous chapter.

REFERENCES

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[3] J. Sinnemäki, S. Sihvo, J. Isojärvi, M. Blom, M. Airaksinen, A. Mäntylä,Automated dose dispensing service for primary healthcare patients: asystematic review, Systematic Reviews 2013, 2:1 doi:10.1186/2046-4053-2-1

[4] R. Skinner, J. Caldwell, P. Vitale, Computerized screening forappropriate dosing of renally eliminated medications, Proc Annu SympComput Appl Med Care. 1994: 971.

[5] Oldridge, GJ, Gray, KM, McDermott, LM and Kirkpatrick, Pilot studyto determine the ability of health-care professionals to undertake drugdose calculations, Internal Medicine Journal, 34 6: 316-319, BlackwellPublishing Ltd.