Traditionally, robots have been heavily used in a wide variety of automotive applications. But, as the performance and reliability of today’s machines continue going up, and costs continue coming down, medical device manufacturers are increasingly investing in assembly robots to improve flexibility, productivity and repeatability.

Several years ago, mentioning the word “robot” to a medical device manufacturer would conjure up images of either robotic-assisted surgery or material handling. While such applications still exist, robots are finding more and more work on medical device assembly lines today. Indeed, blood glucose monitors, inhalers, intravenous (IV) bags, orthopedic implants, pacemakers, stents, syringes and other products are produced with robots.

Robot manufacturers and systems integrators report seeing more and more demand today from the medical device industry. “All types of medical devices are being assembled with robots,” claims Jay Hallberg, regional sales manager at Epson Robots (Carson, CA). “Any device where the product and the process can be defined and staged is a good candidate for robotic assembly.”

“The growth in this sector has been just short of explosive,” adds Brian Jones, section manager at DENSO Robotics (Long Beach, CA). “The aging baby boomers and advances in medical implant technology have driven demand.”

The market is also being propelled by increasing miniaturization and the need for higher productivity in the medical device industry. Jones says his company has witnessed a 54 percent average annual increase in demand during the last 3 years. Many manufacturers specify robots equipped for clean room applications, which adds approximately 20 percent to the pricetag.

Most Class 100 clean room robots have tight seals so that dust and other particulate matter do not escape and contaminate medical devices. Robots for Class 10 clean room applications typically contain a vacuum that is housed either in the arm or in the back of the machine. With the vacuum, dust and other pesky particles cannot move toward end-of-arm tooling.

Small Devices, Big Growth

"As medical devices become smaller, more complex and individually customized, it is economically unfeasible to consider an assembly operation without robotics,” notes Sal Spada, research director for ARC Advisory Group (Dedham, MA). “With the convergence of embedded intelligence and mechanics in medical products, the manufacturing requirements in this industry sector will mirror those experienced in automotive sensors and the semiconductor backend 20 years ago.”

In fact, Spada predicts that the medical device industry will outpace the overall market growth for robotic applications over the next 5 years. Demand for medical device assembly applications will grow 11 percent annually vs. 7 percent for the entire industrial robotics industry. However, the overall market is still relatively small when compared to the primary domain of robotics, such as painting, welding and material handling.

Analysts at Frost & Sullivan Inc. (San Antonio) also see a bright future for robots in medical and pharmaceutical applications. They predict the total market will grow from $394 million in 2004 to $668 million in 2011.

The aging population is driving rapid growth of the medical device market, which is expected to fuel demand for faster and more flexible assembly equipment, such as robots. For instance, the number of surgical procedures performed annually is on the rise, due to aging baby boomers and an increase in elective procedures. Analysts at Medtech Insight (Newport Beach, CA) predict that the total number of open and minimally invasive surgical procedures and device implantations in the United States will exceed 38 million in 2012 vs. 28 million in 2004.

People will also need more mass-produced components to replace old bones and worn-out joints. “Changing demographics are driving [the] orthopedic implant market,” says Harini Subramani, a research analyst at Frost & Sullivan. “As [the] population ages rapidly, a number of age-related conditions, including orthopedic problems, will underpin an increase in the number of implant surgeries.”

According to a recent study conducted by the Freedonia Group Inc. (Cleveland), demand for implantable medical devices, such as artificial hips and knees, will increase more than 10 percent annually to $36.4 billion by 2009. The market for orthopedic implants alone is growing 9 percent annually.

Numerous Benefits

Medical device manufacturers are investing in robots to reduce labor cost, improve product quality and increase reliability. Robots are capable of performing precise, high-quality, high-throughput applications, all within a controlled environment, making them well-suited for the medical device industry. Benchtop robots are ideal for many assembly applications, such as dispensing adhesive, bending wire and inserting plastic tubes.

According to Gerald Vogt, division manager at Stäubli Corp. (Duncan, SC), both articulated and SCARA robots are widely used for assembling medical devices. “Both have their place,” he points out. “[The most important] criteria are speed and the complexity of motion [required for the application].

“Many applications done by robots today could not be done a few years ago,” adds Vogt. “Robots are getting more precise and more intelligent.”

Robots appeal to medical device manufacturers because they offer consistent part quality. They eliminate the variability of manual assembly, while still affording the traceability and consistency of automation.

“Generally, any form of automation, whether fixed or robotic, improves quality and reduces cycle time, and as a result, minimizes expense,” says Carl Traynor, senior general manager at Motoman Inc. (West Carrollton, OH). However, robotic automation offers unique flexibility to medical device manufacturing. This flexibility has significant value to medical device manufacturers, as they are not likely to produce 4 million units of a particular [product].

Rather, the medical device industry has a history of continuous improvement, adds Traynor. What may appear to be slight differences to an end user [can actually be] significant, expensive changes if they cause fixed automation to be reconfigured. Robots allow that reconfiguration to take place with a change of an end-of-arm tool or a change in the position of the tool.

Medical devices that feature parts with consistent dimensions and material thicknesses are typically the easiest to produce with robotics. “Specifically, when tasks at a station or cell require multiple work locations, the introduction of several components or just complex manipulations, a robotic solution can prove to be the best application,” says Roger Nordy, senior business development engineer at Cox Automation Systems (Bloomingdale, IL).

“In many cases, we have found that the flexibility of a robotic solution allows us to integrate and install a solution, and then support the refinement of the production process while we meet our customer’s time scales,” adds Nordy. “Part of our evaluation process is based upon the many inherent attributes [of robots].” These attributes include clean room, electrostatic discharge and wash-down ready features, in addition to machine vision systems, which are all available through the robot controller.

Diverse Applications

Medical device manufacturers are using robots to assemble many different products. “Many of the applications we see involve medical electronics that require precise placement of small amounts of conductive epoxies and similar materials,” says Terry Dunbar, regional sales manager at EFD Inc. (East Providence, RI). “Other applications include attaching blades and balloons to catheters, and applying sealants to implantable devices.

“By combining consistent fluid deposits with precise positioning, tabletop dispensing robots can help device manufacturers easily and cost-effectively automate tedious, labor-intensive tasks, and reduce variability and rejects,” Dunbar points out.

Robots are also commonly used to assemble stents. “The manufacture of stents requires finding and handling very small diameter wire,” says Epson’s Hallberg. “By using three robots equipped with multiple cameras and an internally developed assembly process, [one of our customers] was able to reduce its assembly department from 20 people to only three.”

Hallberg says a manufacturer of implantable devices was also able to make dramatic improvements by investing in robotics. “They had a family of parts with long changeover times from part to part,” he explains. “By using robots and redundant stations for the long changeover portions of the assembly process, they were able to improve their uptime from 55 percent to 98 percent.”

Insulet Corp. (Bedford, MA) is using robots to assemble a device used to deliver insulin to diabetes patients. The OmniPod System integrates insulin infusion and blood glucose monitoring in a safe, easy to use, two-part system.

“We continuously expand our OmniPod production capability in order to satisfy the tremendous demand for this product,” says Kevin Schmid, vice president of manufacturing. “We need advanced robotics [because of] their flexibility, speed and dependability for our assembly operations.” Insulet uses SCARA and six-axis articulated robots to gain a competitive edge with its product, which is assembled in the United States.

In addition to assembly applications, robots are used to test and package medical devices. And, future growth will be driven by laboratory applications.

An extremely large aging population in North America will need new and better drugs to be developed, says Stefan Surpitski, an analyst at ARC Advisory Group. Robots enable the efficient testing of numerous compounds. Manufacturers are expected to leverage robotics in both the production and the design phases of drug development.

Moving vials from one machine to the next is very tedious and mistakes can occur very easily when performed by a human, explains Surpitski. Robots currently working in this space are primarily used to feed other machines such as centrifuges, decappers and analyzers. These material handling applications primarily take place in the sample prep phase where growth is expected to continue.

Becton, Dickinson and Co. (Franklin Lake, NJ) uses four-axis SCARA robots to manufacture its BD ProbeTec system, which is used for in vitro diagnostic applications. The robots are used in pipette-transfer applications, which demand a highly controlled and regulated laboratory environment.

The robots ensure reliability and performance. Compared to manual pipetting in a laboratory environment, the robots reduce repetitive motions and errors, thereby eliminating fatigue and distraction, which can critically affect important diagnostic results. They enable BD’s limited number of technologists to work at a greater level of efficiency by increasing their productivity and minimizing their risk of injury.

Robots are also used to do the actual sample processing and analysis. Surpitski predicts that manufacturers and integrators will experience large growth as the clinical markets seek to automate.

The public health sector, which is comprised of hospitals and clinics, will also help spur demand for robots. Many of these facilities are still using systems that have not been updated in 30 or 40 years in some cases, notes Surpitski. The slow emergence of viruses and diseases, such as the avian bird flu, will drive the overdue modernization of the public health sector. Robotics will be key components of that modernization.

In addition, the increased reliability of robots is allowing them to be placed in much closer proximity to humans. For example, Surpitski says industrial robots are going to be used in greater numbers to position patients in radiology applications. However, he says autonomous operation of these robots is still far off.

Robotic Challenges

Medical device engineers are faced with numerous challenges when using robots for assembly applications, such as accuracy, repeatability and speed. Because medical products typically use small parts, robots must be programmed to operate with extremely tight tolerances. In addition, clean room environments demand extra functions. For instance, equipment must be robustly sealed so that it can withstand frequent wash downs.

Most robot vendors have been able to adapt their standard products to fit the unique needs of medical device manufacturers. “[They] have environments that are different from other industries,” says Hallberg. “These environments include dry rooms and [clean rooms].

“Some of the materials being used are expensive and fragile,” adds Hallberg. “The handling of these products is difficult. Micro assembly, the assembly of very small parts with very tight tolerances, is becoming more prevalent in the industry. Metal particulates can also be an issue when dealing with implantable devices.” As medical devices get smaller and smaller, robots and other automated equipment will become essential.

Unfortunately, small parts can be difficult to manipulate. According to Dan Peretz, director of sales at DE-STA-CO (Madison Heights, MI), the biggest challengesto using robots to assemble medical devices is part alignment, especially molded plastic parts. “Plastic parts can be slick due to material composition,” he points out. “[They are] also delicate.”

Flexible parts are always more difficult to assemble. Parts that are not rigid, such as springs or flexible plastics, pose problems with maintaining part position and orientation.

To be effective, robotic grippers must apply enough pressure to hold the part without damaging it in the process. Also, small parts are often presented in arrays spaced closely together. The grippers must be small themselves to work in these fine-pitch matrices.

Gripping and releasing small parts is typically more challenging because of the accuracy, repeatability and speed involved. The smaller the part, the more challenging the part is to grip and release. As a general rule, with smaller parts, more accuracy is involved in the positioning. And, higher quantities require lower cycle times.

Size and speed are also a big challenge to using robots to assemble medical devices, says Jesse Hayes, product manager for automation components at Schunk Inc. (Morrisville, NC). “Depending on the geometry and available features that we are able to grip on, it can be difficult,” he notes. Fortunately, there are many different options available so that engineers can select the perfect gripper for the application.

“In many instances, fixturing can be designed to compensate for component flexibility and movement,” adds EFD’s Dunbar. “Some tubing applications can be difficult for robots, such as attaching fittings when a 360-degree bead around the joint is required. But, other tubing applications, such as those where the fitting has a butt joint into which adhesive can be dispensed, can be speeded up with the use of a robot.”

Several different types of robots are available for manipulating small medical device parts and components. The best configuration to use typically depends on the application and the work envelope. Cycle times, accuracy and flexibility can dictate a choice between one type of robot or another. Other considerations include the process parameters, part weight, repeatability and the working area to complete the tasks.

For high-speed, pick-and-place work with small parts, most manufacturers turn to SCARA robots. However, articulated robots are also ideal for assembling small parts. They tend to be more flexible to accommodate frequent changeovers.

“It really depends on the application,” says DENSO’s Jones. “Very high volume applications assembling parts in a horizontal plane, such as simple pick-and-place with high throughput, would benefit more from four-axis robots. Complex applications, such as changing orientation or something involving careful insertion, would require six-axis robots.”

Advances in motion control hardware and software are making it easier for medical device manufacturers to use robots on their assembly lines. “Many of the processes employed to manufacture medical devices include hundreds, if not thousands, of programmed positions,” says Motoman’s Traynor. “As a result, historically, robots have required a substantial effort to both integrate and program in order to manufacture medical devices. This effort related directly to higher cost and longer lead times for robotic systems.”

“Industrial robot manufacturers face several challenges in their effort to establish themselves in medical applications,” adds Kishan Bhat, a Frost & Sullivan research analyst. “Key among these is the incompatibility of their controller software with existing installed equipment.

“In most cases, this proprietary software is not upgraded frequently to meet the changing application requirements,” adds Bhat. “Manufacturers need to find a way to address this problem. The introduction of open architecture controllers [should] go a long way in reducing the impact of this challenge.”

“Recent improvements in communications and in the integration of motion with discrete control allow [us] to create more flexible, more robust machines for our customers in shorter periods of time,” says Cox Automation’s Nordy. “In the past, communication between dissimilar control systems was very time consuming to develop, often relying on the lowest common denominator: RS232.

“At the control level, the advent of open protocols such as Profibus, EtherNet/IP and DeviceNet allow simple, fast and robust data sharing between intelligent devices, such as data sharing between a machine controller and a vision system,” explains Nordy. “The integration of discrete control with complex motion greatly simplifies the entire process of medical device automation.

“From a machine perspective, integrating motion with discrete control eliminates control wiring and communication delays while increasing program flexibility,” adds Nordy. “Integrated control reduces software design, documentation and validation as we focus on a single control element.”