ID Readers save assembly time and improve tracking of surgical instruments

cognes-surgical-instrumentsAssembling 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. 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.

The Challenge:

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. The surgical set assembly challenge “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.” “There are many problems with the traditional approach of using count sheets,” said Janice Hardrath, Chief Technology Officer for Censis. “Count sheets are often produced on a spreadsheet and then photocopied. When the list changes it is difficult to retrieve all of the old incorrect paper lists and replace them with accurate information. The biggest problem comes when surgical sets reach the OR with incorrect instruments or instruments missing. This often causes delays in the OR, risks to the outcomes of the surgical procedures and dissatisfied surgeons.” Another problem with the old approach is that there is no way to identify or document instruments or track their movements. In the event of a biological test problem with a sterilizer load, the hospital needs to know exactly which instruments were in the load and their current location. This is difficult with the conventional approach because it is necessary to rely upon handwritten notes and the memory of the person who assembled the set. Hospitals often lose large numbers of instruments and spend considerable amounts of money for replacements. Maintenance is also supposed to be performed on instruments after a certain number of uses but with the manual system there’s no way to know how often each instrument is used so instruments are often over- or under-maintained. Finding the right ID reader has also been a challenge. “We went through five different generations of scanners,” Hardrath said. “Each generation was better than the previous one yet only the latest generation has met our requirements in terms of reading the mark quickly and reliably.” The instruments are typically a silvery metal, normally either stainless steel or aluminum. Some have a matte surface while others have a mirror surface. Some instruments are flat and others are curved. The reflectivity of the surface makes it difficult to form a good image of the mark. Generally, the scanners that Censis has tried in the past were able to read the marks by using algorithms that account for the reflectivity of the surface. The problem is that the scanning and computation took too long. When delays occurred, technicians typically pulled the instrument away and started over again or went back to the previous manual methods. The best results are achieved by moving the instrument slowly from one side to the others so that the scanner can view the mark from different angles and apply algorithms to account for the reflectivity.

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.

Finding the right ID reader
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.  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. Hardrath set up what she called a scan-off competition to find the best possible vision system for the job.  I put together an assortment of 30 different instruments of various types including curved, flat, shiny, matte, colored and uncolored. I lined up three of the preferred models on the market, including the Cognex DataMan 7500. We asked a number of different people to scan each of the instruments. Then we measured the results, the amount of time required to scan each instrument and the reaction of the people participating to each scanner.  The Cognex DataMan 7500 was noticeably superior to the other devices, Hardrath said.  Most of the people that did the scanning commented that it was faster and easier to get a good scan with this ID reader. So we made the decision to exclusively offer the Cognex instrument with Censitrac. We now have 250 DataMan 7500 scanners out in the field. The average hospital has five of these scanners and the largest has 30. Our customers love them. Most have decided to replace their earlier generation scanners with the new Cognex units.  Cognex DataMan 7500 series ID readers achieve their unique capabilities with an innovative combination of lighting, software and optics. These ID readers incorporate software that handles a wide range of degradation to the appearance of the code. DataMan readers can illuminate marks of any type on any surface. The integrated diffuser provides soft illumination required for highly reflective parts such as electrochemical etched marks on shiny round surfaces. The Cognex DataMan 7500 is the first to offer a handheld verification solution that meets the requirements of the Association for Automatic Identification and Mobility (AIM) 2D Data Matrix code quality grading requirements. Censitrac overcomes the problems associated with manual methods of tracking instruments and automated methods that track the set rather than the individual instrument. The software automates the set assembly process to ensure 100% rate assembly and automatically tracks the movement of each instrument whether it is in a set or in loose inventory. This makes it easy to locate any instrument immediately. Censitrac measures instrument usage, including which instruments in sets were used in procedures and which were not, and determines exactly when maintenance is due.

Major improvements at Saint Thomas Hospital

“From the first day that we started using Censitrac we saw a substantial reduction in the number of errors,” Stefanik said. “Just as important, we now know where every instrument set is located. Sometimes the OR will call and say that an instrument is missing. In most cases, I will look it up in Censitrac and discover that it was scanned and put into the set that was sent to the OR. I will let the OR know and in most cases they will look around and find it in the OR. If not, we will scan and send them up a replacement without wasting time looking for the one that was already placed into the set.”

“We saw a major improvement when Censis upgraded us to the Cognex DataMan 7500 series handheld ID readers,” Stefanik added. “The first two scanners that we used were stationary and we had to run the instrument under them which was somewhat awkward. The DataMan 7500 on the other hand, is portable so we can move it over multiple instruments at a time, which saves time. The DataMan scanner is much faster than others we have used and the accuracy of the instrument is 100%. The DataMan scanner is also the most rugged we have seen. In the past, we were breaking them right and left but as far as I know we have never broken a Cognex scanner.”

ID Readers Enable Part Traceability of Direct Part Mark Products

cognex-id-reader-enables-part-tracebility-of-direct-part-mark-productWhen Canadian energy services company Packers Plus needed to read challenging dot peened codes on a variety of parts, they specified Cognex® DataMan® handheld ID readers. The company’s StackFRAC® system consists of many parts, each marked with a unique 2D Data Matrix code that enables traceability throughout its useful life.

Traceability delivers two important benefits for Packers Plus. First, it reduces rework costs by providing better manufacturing process control and ensuring that the right parts are used at every stage of production. Second, it enables Packers Plus to quickly retrieve information on 100% of the parts in every system that has been shipped out their door, including production history and quality control information.

In the past, Packers Plus manually recorded information such as lot numbers, heat numbers, quality control measurements and other information in a spreadsheet. “This was a very time-consuming manual process that took approximately four hours for each product, so we only did it when necessary,” said Marlon Leggott, Director of Manufacturing for Packers Plus. “Another problem with the manual process is that it is susceptible to mistakes, such as data entry errors.”

Selecting marking and reading tools

Packers Plus considered a number of different options for improving traceability when it installed its new ERP system. Kurtis Weber of iTech Tool Technology helped Packers Plus design the traceability solution. “We looked at labels with standard line bar codes but determined they would have to come off during assembly, which would negate many of the advantages of serialization,” Weber said. “RFID tags don’t work well with various metal parts because of interference with reading and writing the tags. Laser marking overcomes all of these problems but laser marking machines begin at $50,000 and have to be enclosed — which causes problems when used to mark large pieces — and cannot easily be moved from place to place. We recommended a dot peen marking system because it is permanent, does not rely on fragile RF transmissions, costs only about $10,000 per machine, and is available in fixed or mobile models. The mobility allows us to easily move around the plant and successfully mark any size part in a variety of orientations.” With dot peen marking, a carbide or diamond-tipped stylus pneumatically or electromechanically strikes the material surface.

Packers Plus then faced the difficult challenge of reading the marked parts. The challenge arises from the fact that Packers Plus makes parts with curved surfaces and many different materials and coating combinations. Nearly any reader can be adjusted to provide perfect accuracy on a particular combination but Packers Plus wanted a reader that could deliver high levels of accuracy on any part. “We recommended Cognex DataMan handheld readers because they adjust the lighting to match the part and use the industry’s most  advanced algorithm  for picking out the 2D Data Matrix code from the background,” Weber said. “This is the only product I have seen that is capable of accurately reading the wide range of parts used by Packers Plus.” 

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ID Readers Enable Part Traceability for Direct Part Marked Products

KIA Motors achieves 99% read rates with Cognex barcode readers

Cognex Kia Motors achies99% read rates with Cognex Barcode ReadersKIA Motors, located in Korea, manages their traceability program on their engine and transmission parts using 2-D Data Matrix direct part marked (DPM) codes. A car transmission consists of as many as 300,000 parts. Among them, the key components (e.g., differential gear, T/F driver gear, T/F driven gear, carrier, O/D clutch, transmission case, housing, valve body, etc.) are traced throughout the production process. Additionally key components on the engine, which is comprised of around 200,000 parts (e.g., the piston, cylinder head, engine block, CAM shaft, and crank shaft) are traced throughout the manufacturing and distributing processes.

KIA Motors focused on enhancing 2-D Data Matrix read rates for traceability after it shifted its production system to the 6-speed transmission production line. The company’s conventional transmission production line produced approximately 1,800 units daily but only delivered 96-97% read rates. Their engine line, which produced 1,300-1,400 engines daily, had read rates that were under 97%. KIA Motors knew that an increase in read rates by as little as 2-3% in this production line would deliver various benefits, such production yield and reduction of manufacturing costs as well as improved work efficiency.


The previous barcode reader frequently stopped the manufacturing machines due to the failure to read codes. Because it was manually operated, it was hard to match the manufacturing cycle on time, which, in turn, decreased work efficiency and production yield. Furthermore, there was a possibility of using inappropriate parts if the code read was incorrect, which could cause product defects. This particular line had challenging Data Matrix codes to read since the s-speed transmission parts are small. Furthermore, KIA Motors downsized from 10×10 to 5×5, marking space. As a result, marking quality also declined.

Because KIA Motors’ auto parts are assembled with anti-rust oil spray, one of the challenges for the reader to avoid is errors caused by oil on the code. In addition, the 2-D Data Matrix codes can be stained or damaged by dirt or scratches, even though they have been washed and kept clean. And, with the reduced marking size, the codes are very small and have greater variation in marking quality, making them more difficult to read.


The Cognex 2DMax+ code reading algorithm can read virtually any barcode regardless of the damage or the surface it is marked on. In addition, Cognex barcode readers offer Ethernet connectivity so they can directly integrate into the factory network, and direct communication with PLC possible without a transmission device.


Improved read rates from 96-97% to 99%, and allowed the manufacturing cycle to match the inspection time.

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