Medical Devices

ID Readers save assembly time and improve tracking of surgical instruments


Assembling accurate sets of instruments for the many different types of surgery performed in a typical hospital is a time-consuming and difficult manual task at most hospitals. Technicians in the central sterile department typically wash instruments, re-assemble them into sets based on pick lists provided by surgeons, and sterilize them so they are ready for the next day’s surgery. The problem is that when surgeons open the kit the next day instruments may be missing and it may be necessary to delay surgery while technicians race around looking for them.

Censis has developed a software product called Censitrac that allows hospitals to set up surgical set pick lists and then ensures that the correct instruments are loaded into surgical sets. A 2D Data Matrix barcode is electrochemically applied to each instrument and this barcode is scanned during the assembly process to ensure accurate set assembly and track the location of every instrument. It’s very difficult to read a barcode on the shiny surface of a surgical instrument. Censis went through five different generations of ID readers before it found one, the Cognex DataMan® 7500, that provides the accuracy, speed and ease of use required by this critical application.

“In the past we assembled instruments based on a document that we called a count sheet,” said Pat Stefanik, Registered Nurse and Central Sterile Manager at Saint Thomas Hospital, Nashville, Tennessee. “This task was complicated by the wide range of individual preferences among the different surgeons and by the large number of non-traditional instruments that are used by our surgeons. For example, some like all their curettes together and all their scissors together while others want all the ringed instruments together. The result was that the relationship between Central Sterile and Surgical was not as good as it should have been. An instrument would turn up missing and the first thought was that Central Sterile had made a mistake.”

An innovative solution

The founders of Censis developed the concept of putting a bar code on each instrument and maintaining the pick list within a software package. The technician assembling the kit then scans in each instrument and the software ensures that all of the proper instruments are in the kit. The process of marking the instruments and then accurately reading that mark has proved to be the most difficult part of the entire concept. “We started out using a laser to etch the instruments, then went to an adhesive label with a 2D Data Matrix barcode,” Hardrath said. It was difficult to keep the adhesive working during wash and sterilization so Censis tried laser bonding the label. Finally, the company went to an electrochemical marking technique that applies a 3mm Data Matrix barcode. This marking method has been demonstrated to provide the durability and readability needed to stand up to surgery, washing and sterilization.