They call it RDS ROBOTx and it's definitely not your corner drug store. Designed for large central-fill and mail-order pharmaceutical operations, this automation showcase harnesses industrial robots, a powerful server, PLCs, RFID and much more to deliver unmatched productivity to drug dispensing.
The system is the latest in a parade of technical advances to ease the burdens of pharmacists challenged to meet the medication needs of an aging population. More than 1,200 pharmacies across the country, for example, use Innovation Assoc.'s PharmASSIST technology, which features an automated counting system to dispense the precise number of capsules when a pharmacist enters a prescription on a computer.
But the RDS system, like the $2.1 million operation Innovation Assoc. has installed at the U.S. Air Force's 10th Medical Group in Colorado, takes automation to a whole new level. Featuring two robots, the system routinely fills more than 3,600 prescriptions a day for several area medical facilities. Compare that to the 350 prescriptions a druggist can typically process in the same time.
While relieving pharmacists from the most tedious parts of their jobs, RDS by no means takes these professionals out of the picture. At the final stage of the operation, a pharmacist inspects every filled prescription and uses a computer workstation to verify it.
“The system really frees the pharmacist to do the important tasks, such as insuring that the patient is getting the right medication and that it will not cause harmful reactions with other medications he may be taking,” says Bruce Holtje, senior staff engineer for Innovation Assoc., based in Johnson City, NY.
The Path of Automation
Taking up about 2,000 sq ft, the typical RDS system starts at the vial delivery stage, which features an unscrambler unit, designed by Innovation Assoc. in conjunction with Pennsylvania-based Palace Packaging. The device sorts vials of three different sizes from hoppers and places them on a queue, where the vial size for each prescription is verified and a bar-coded label is applied. A clear pneumatic tube then delivers the vials at 30 mph to the next stage of the system — robot dispensing.
“We use compressed air to create both a pressure wave behind the vial, as well as a low-pressure area ahead of the vial,” says Holtje. “Conversely, we can create a low-pressure behind the vial to slow it down. This allows the vial handling to be remote from the secure drug handling area.”
The system uses air from a 5-hp central compressor not only for this pneumatic vial transport operation, but also for the unscrambler, robot end effectors and some conveyor controls.
Once the vials arrive at the dispensing station, an ABB 140 industrial robot picks up each labeled vial from the landing platform and positions it under one of 360 drug dispensers, which automatically release the precise number of pills into a vial.
“This is a small clean room robot that is ideal for light assembly and very cost effective,” says Jim McGonigal, director of systems engineering. “We picked a robot that had the size and reach to make maximum use of our automated dispensers.”
Holtje says the real beauty of the system is the automatic dispensers. “Once a prescription comes into the system, the appropriate dispenser for that medication already starts counting the capsules needed. The robot doesn't receive a vial for that prescription until the dispenser is ready to deliver the full number of tablets. And we then regulate the speed of the robot, depending on how full the vial is, so it doesn't spill any product,“ he says.
After each prescription is filled, the robot places the vial on a PLC-controlled Faux Seal Station, which uses an ultrasonic horn to apply a temporary adhesive-film seal to protect the contents as the vial moves through the final stages of the system. After a test cycle within the station to ensure the seal is in place, the vial drops into an 8 x 12 inch plastic tote that carries it via a rigid-link conveyor to final inspection.
Vital Role of RFID
The two-tiered, tote-conveying operation demonstrates the importance of RFID to the whole RDS system. An RFID tag is embedded on the bottom of each tote, which is read by transponders in the conveyor. At the tote initiation stage, the system writes to the tag both the routing information for that prescription on the conveyor system, as well as information on the prescription itself. RDS software controls which prescriptions go in particular totes. If a person has multiple prescriptions, all of them will be in the same tote. In the case of single prescriptions for different individuals, up to 10 can reside in the same tote to boost throughput.
Totes with filled prescriptions requiring no further action ride on the top tier of the conveyor. Those that need further attention, such as prescriptions for inhalers, liquids or ointments, are routed on the bottom conveyor to a manual station where a pharmacist technician uses a transponder to read the tag and fill the prescription.
In the case of vials, pharmacists at the final inspection station read the information on each tote RFID tag and the bar codes on individual vials. They also visually inspect the contents, verify each prescription and review relevant health history on their computer workstations. Lastly, the pharmacist replaces the temporary seals with a permanent cap, bags the order with a patient information sheet and places the empty tote back on the lower conveyor for reassignment.
Brains Behind the Brawn
Central to this entire system is a powerful central server that coordinates four Allen Bradley PLCs and also sorts the flood of prescriptions coming in each day. In the case of the Air Force's Colorado installation, for example, the RDS server must process prescription data sent from five major health facilities.
“There's a tremendous amount of computer processing involved,” says McGonigal. “For example, the server will automatically sort large volumes of orders from a particular health facility so that they can be filled together for maximum efficiency.”
Innovation Assoc. designed the system with a small team working on a tight schedule. Key design tools included AutoCAD 3-D modeling software and home-grown software to simulate the system and demonstrate its operation to customers.
What was the biggest challenge in pulling together such diverse technologies? “Much of it boils down to finding the right components to fit the job,” says Holtje. “If I don't need to position something to micron resolution, I don't need a servo motor that will do that. We want to build a high-quality system, but our customers can't afford to pay for excess performance.”