Design and Implement on Automated Pharmacy System
HongLei Che*, Chao Yun, and JiYuan Zang
School of Mechanical Engineering and Automation,
Beihang University, NO. 37 Xueyuan Road, Haidian District,
Beijing, 100191, P.R. China
sychehonglei@163.com, cyun@vip.sina.com,
zangjy1981@126.com
Abstract. This paper introduces that the research design of the automated
pharmacy system which is aim at accessing the packed drugs, which shows that
the system should have three main functions and implementations of three main
functions. Introducing the detailed structural design of the automatic medicineinput system, dense medicine-store system and medicine-output system; and
researching on control methods of each executing agency in the system. In the
end, it is to design the function of system software. The system has been
developed and applied in Hospital outpatient pharmacy and it is in good
working condition.
Keywords: Packed Drugs, Automated pharmacy, Automatic medicine-input
system, Dense medicine-store system, Medicine-output system, Controlling
system.
1 Introduction
The pharmacy is the pivotal issue of hospital. At present, the method of medicinestore mainly is fixed shelves in domestic hospital pharmacy, but this accessing mode
has its unavoidable disadvantages: 1) drug storage is scattered and space utilization
rate is very low; 2) pharmacist has high labor intensity and low working efficiency; 3)
manual medicine-output makes mistakes easily, and cause drug accidents. Therefore,
the hospital pharmacy automation is the new trend of development of pharmacy, and
it is also an important sign of the service and working concept innovation [3].
This paper introduces the automated pharmacy system which mainly consists of
automatic medicine-input system, dense medicine-store system and medicine-output
system and database management system. The system can implement three basic
functions which are medicine-input, dense medicine-store and medicine-output.
2 Automated Pharmacy System Ontology Structure
Automated pharmacy system ontology structure, is shown in Fig. 1 as follows,
including automatic medicine-input system, dense medicine-store system and
medicine-output system.
*
Corresponding author.
S. Lin and X. Huang (Eds.): CSEE 2011, Part I, CCIS 214, pp. 167–175, 2011.
© Springer-Verlag Berlin Heidelberg 2011
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H. Che, C. Yun, and J. Zang
Fig. 1. Automated Pharmacy
2.1 Automatic Medicine-Input System
Automatic medicine-input system mainly consists of medicine-input test system,
medicine-input transmission system and medicine-input manipulator.
Medicine-input detection system consists of operating platform, 3 laser rangefinding sensors and a PISO813 data acquisition card, as shown in Fig. 2. Data
acquisition card collect real-time the kit length, width and height dimensions that are
needed to add to dense storage system through three laser range-finding sensors, if the
size of the collection is same as the size of kit in the data base, then it is transmitted to
medicine-input manipulator, or generating error message.
Fig. 2. Detection of Medicine-input System
Design and Implement on Automated Pharmacy System
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Medicine-input transmission system consists of horizontal linear motion
unit, vertical linear motion unit and synchronous transmission mechanism, as Fig. 3
shows.
Fig. 3. Transmission of Medicine-input System
Medicine-input manipulator consists of pedestal body, stepping motor, lifting
board, transmission system, and rotating electromagnet, as shown in Fig. 4.
Fig. 4. Manipulator
The manipulators accept drugs that are tested, medicine-input transmission system
will locate the medicine-input manipulator in the storage number of dense storage
system, and stepping motor turned a certain Angle according to height of the kit, the
lifting board lifts up the corresponding height driven by the synchronous belt. When kits
rise to higher than the frame former board, because of the gravity, drugs will slide into
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the slot of the frame former board, and then slide into the slot of medicine storage in the
dense storage system. Step motor repeats the above movements, until the lifting board
hands out the last kit. In the process, if drugs decline due to friction, then rotate
electromagnet work, drive the dial the piece to click, and make drugs slide successfully.
2.2 Dense Storage Systems
Dense storage system consists of roller type slope store pharmacy and roller store
medicine slot, as shown in Fig. 5.
Roller type slope store pharmacy mainly consists of frame body, support beam, and
roller medicine-store slot, frame body is 3540mm x built 1440mm x 2450mm cube
structure which is composed by section aluminum; Support beam is constructed by
aluminum extrusion, it and frame body are assembly constituted the installation
matrix of roller store medicine slot.
Fig. 5. Dense Storage System
Roller medicine-store slot consists of roller, rolling shaft, parting strip, border and
beams, as shown in figure 6. Beams and border compose the installation matrix of the
roller medicine-store slot, the roller that is 10mm diameter is set into rolling shaft, the
rolling shaft uniformly distributed with 20mm of separation distance. Because widths
of pharmacy packed drugs are different, the bar is set into the rolling shaft; the space
between adjacent parting strips constructs the minimum storage unit of packed drugs,
because the parting strip is set into the rolling shaft, to enhance the overall rigidity of
the roller medicine-store slot.
Design idea is based on gravity blanking principle; the roller medicine-store slot is
installed in store pharmacy with 15 ° angle, then drugs are affected by its own gravity
after getting into store, and automatic slide into the opening of medicine-out of the
dense storage system, wait for medicine-out.
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Fig. 6. Roller Medicine-store Slot
2.3 Automatic Medicine-Out System
Automatic medicine-out system consists of the medicine-out driver and elevators. The
packed drugs in the dense storage system is placed at the tilt roller medicine-store
slot, each medicine-store slot keeps the same type of drugs, and form matrix
arrangement as a whole. When there is no medicine-out action, the packed drugs is
reliably located by fixed block shaft that is installed in the flanges of both ends.
Medicine-out driver consists of electromagnet and flap, as shown in Fig. 7. The
flap is installed in the ejector rob which is in front of electromagnets, After
electromagnet electrified, the ejector rob contracts to drive flap rotate around of fixed
axis, the front-end of the kit is jacked up by the flap at this time, when the bottom of
the kit is higher than the limit block shaft, then take the medicine-out action. Then,
the kit slides to belt of the elevator from the slope of the elevator.
Fig. 7. Medicine-out Driver
Elevator consists of guide rail, belt line, aluminum paddles, flap, transmission
system, photoelectric sensor that is for testing drugs and self-protection sensor, as
shown in Fig. 8 below. Elevator takes the lifting motion along the two guide rails in
the vertical plane, after locating the position according to the layer position of
medicine-store, the medicine-out driver acts and completes the medicine-out. Drugs
are taken out and go through the photoelectric sensor testing surface; sensor sends
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detected signals to PLC, then count, and match with the number of drugs in the
prescription. Taken drugs fall on the belt line directly, when drugs are taken
completely, belt line transport drugs to the opening of medicine-out, then the flap is
open, drugs are sent out, and complete the deployment of prescription drugs.
Fig. 8. Elevator
When drugs are blocked in the roller medicine-store slot because of the package
quality, or because the slot surface is not smooth enough and so on, if the elevator
continues to move, then the kit will interfere with its movement, when the problem is
serious, which will damage the elevator and medicine-store slot. So there are two
groups of bijective photoelectric sensors that are installed in elevator to be used for
protection and detection. When kits or other objects block the detective light rays of
sensors, the control system will stop elevator’s movement; when objects are removed,
and detective light rays can pass, then the control system will control elevator to
continue to move.
3 Automated Pharmacy System Control System
The control system of automated pharmacy system adopts the function structure
framework as shown in Fig. 9. System is divided into four functional modules:
management level, monitoring level and control level, executive level.
Management level: system prescribing information, drugs warehousing information,
inventory information management center. Management level establishes the drug
inventory database, which can receive HIS prescription information, according to the
drug inventory, to construct medicine-input list, according to the principle that is
“first-in first-out”, add the store address and quantity information to prescription
drugs, distribute the prescription information that is dealt with, after receiving
feedback value from the number of medicine-out, modify drugs inventory
information, then dynamic real-time manage drugs inventory.
Monitoring level: in the middle layer, makes information interaction with
management level, receives management level’s prescribing information, makes task
scheduling for each executive device, sends the control instruction that is generated by
monitor program to control level; and communicates with control level, reads feedback
quantitative values, monitors all kinds of signs and makes logical judgment processing.
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Hospital Information Management System HIS
TCP/IP
Manageme
nt Level
Automated Pharmacy Service Computer
TCP/IP
Monitoring
Level
Automated Pharmacy IPC
RS232
ISA
PCI
PISO813 Data
Acquisition Card
PMAC Motion Control Card
Controlling
Level
CP1H PLC
AC Motors
Rotating
Electromagnet
Photoelectric
Sensors
Setpper Motor
Drive
Bijective
Sensors
Limit Level
Sensors
Zero Level
Sensors
Servo Drive
Llaser Sensor 3
Laser Sensor 2
Laser Ssensor 1
Executive
Level
Setpper Motors
Servo Motors
Fig. 9. The Structure of Automated Pharmacy Controlling System
Control level: according to control instruction that is sent by monitoring level calls
the corresponding bottom control procedures, then to control execution level parts.
Executive level: accepts control level programming instructions, drives executive
level motor to run and accords with requirements; kits detection, protection detection
and system zero limit detection.
4 Automated Pharmacy System Software System
Software system mainly consists of automatic medicine-input system and automatic
medicine-output system, specific functions as follows.
4.1 Automatic Medicine-Input Software System
Automatic medicine-input program flow is shown in Fig. 10 as follows.
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Beginning
Initialization
NO
Whether medicine-in?
YES
Determine the number of the kits
which will be put in the roller
medicine-store slot.
Manipulator prepare to motion.
The kits which will be put in the
roller medicine-store slot would be
put on belt line of automatic
medicine-input system.
Laser sensors detect length, width
and height dimensions of the kit.
Whether the kit dimensions
consistent with the database?
NO
YES
Delivery the kits to the
manipulator
Medicine-input transmission
system take the manipulator to the
roller medicine-store slot
The manipulator let the kits slide
in the roller medicine-store slot
The manipulator and medicineinput transmission reset
Medicine-input accomplish
Fig. 10. The Program of Automatic Medicine-input
The combination of medicine-input testing system, medicine-input transmission
system and medicine-input manipulator realized the drug batch supplies. As
medicine-input, pharmacist put supply of drugs into medicine-input detection system,
through the analysis of the size information that is collected by the laser displacement
sensors, the drug that is correctly placed is conveyed to the medicine-input
manipulator by medicine-input detection system. After the manipulator with
medicine-input transmission system moves to supply medicine-store slot, the
manipulator makes the action, supplies the drug into medicine-store slot of dense
storage system.
4.2 Automatic Medicine-Output Software Systems
The combination of medicine-output driver and elevator realized the drugs batch
output. As drugs out, the system reads the drug store bits information in database,
elevator moves to the location of drugs, the medicine-out driver acts, counting sensor
sends the quantity of drugs of feedback to database.
After completing this prescription medicine-out, elevator moves to the opening
of medicine-out, the belt line of elevator and flap act at the same time, completes
the medicine out. Automatic medicine-out program flow is shown in Fig. 11 as
follows.
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175
Beginning
NO
Initialization
Read prescribing information
YES
The elevator moves to the kits
export
Belt line of elevator motion
Servo motor positioning motion
Whether positioning
motion of elevator is
accomplished?
Whether the kits of
prescription is
accomplished?
NO
The flap of elevator open
Delay 3 seconds, the kits slide out
of the elevator
The flap of elevator reset
YES
Counting the number of the kits
and feedback the actual number
to the database
The belt line of elevator reset
·
Medicine-out accomplished
Fig. 11. The Program of Automatic Medicine-output
5 Conclusions
This paper introduces the ontology structure, the control system and the design of
software system of automation pharmacy system, at present, the operation of this
system in hospital is in good condition, which proves that the system design is
reasonable and feasible.
References
1. Liu, X.g., Yun, C., Zhao, X.f., Wang, W., Ma, Y.: Design and application on
automatization device of pharmacy. Journal of Machine Design, 65–67 (2009)
2. Zhao, X.f., Yun, C., Liu, X.g., Wang, W.: Optimization for Scheduling of Auto-pharmacy
System. Computer Engineering 193-195, 200 (2009)
3. Chen, L.: The Research and Its Implement of a New Type Intelligent Dispensing System
for Chinese Medicine. Sichuan University, ChenDu (2004)
4. Subramanyan, G.S., Yokoe, D.S., Sharnprapai, S., Nardell, E., McCray, E., Platt, R.: Using
Automated Pharmacy Records to Assess the Management of Tuberculosis. Emerging
Infectious Disease 5(6), 788 (1999)
5. Thomsen, C.J.: A Real Life Look at Automated Pharmacy Workflow Systems. National
Association of Chain Drug Stores 1, 29 (2005)
6. Thomas, M.P.: Medication Errors. Clinical Pediatrics 4, 287 (2003)