Material and equipment innovations, coupled with the stepped-up collaborative efforts of device manufacturers and their supply partners, continue to advance the development of micro parts and devices used in minimally invasive surgical (MIS) procedures for orthopedic, neurostimulation, and cardio, to name a few disciplines. This article takes a closer look at this trend and how smaller parts and devices will likely play bigger roles in the advancement of robotic surgery and telesurgery, followed by examples of robotic platforms in use at healthcare facilities in the United States and abroad.

Equipment and Material Innovations Drive Development

Much of the medical market’s miniaturization trend is made possible by custom-engineered micro extrusions and enhanced medical-grade silicone elastomers. Micro extrusion processing performed below the submillimeter (0.004 in.) range employs highly modified equipment featuring innovations in extrusion head, tool, and screw designs. These innovations have contributed greatly to such advancements as the production of micro extruded, thin-walled tubing down to 0.002 in., and outside and inside diameters down to 0.010 and 0.004 in. — potentially contributing to a myriad of MIS procedures.

Such micro extrusion capabilities recently led to the development of a narrow two-layer extrusion for orthopedic applications, with the core serving as an eluting rod while the outer concentric layer controls elution in MIS procedures. This breakthrough was the result of a multiyear collaboration that started with the elution concept; then the testing of concentrations of the additive to determine how it behaves over time; and finally the development of an outer jacket to lengthen and flatten the elution curve. It took many iterations and additional extruder heads to accomplish this complex tubing to ensure precise elution.

Another area of medicine driving a reduction in device size limits is neurostimulation, which uses an implantable neurostimulator for brain and nerve stimulation to treat disorders such as epilepsy, Parkinson’s, and Tourette syndrome, and spinal-cord stimulation used as chronic-pain therapy. The diameter of extruded tubing used to deliver paindisrupting electrical signals to the brain or spine commonly meets tolerances of ±0.001 in. Such tolerances are being pushed even further thanks to advancements in quality process control and monitoring systems and the prowess of today’s engineering teams.

And when it comes to matters of the heart, cardiac catheterization, a procedure to examine how well a heart is working, requires a thin, hollow tube (catheter) for insertion into a large blood vessel that leads to the heart. The narrower the tube, the less invasive the procedure.

These developments would not be possible without today’s platinum-cured silicones, which eliminate the secondary operations associated with their peroxide-cured counterparts, including post-curing to remove by-products, such as volatile organic compounds, while offering faster cure times at lower temperatures.

Not so long ago, cure profiles were tested at 350 °F. Today, materials are cured at 250 °F. These cooler cure temperatures enable better flow, less process variation, and faster cure times. Also, materials cured at lower temperatures enable risk-free bonding to a range of substrates. In the case of cable jacketing for a heart pump, internal components, such as insulators, will not be damaged. And with so many readily available formulations, today’s platinum-cured silicones can be formulated to bond with metals used in implants, such as titanium, stainless steel, and nitinol and such plastics as polycarbonate, polyester, and polyetheretherketone, commonly known as PEEK.

Another area driving a reduction in size and tolerances is geometric transition extrusions for wound drains, hemo-dialysis tubing, and catheters. To accomplish these extrusions, a process by which tool components can be moved to change tubing geometry enables a single lumen to transition to multiple lumens, or split from a multi-lumen tube into two or three single-lumen tubes. Applications include wound drains, offration bumps, and discrete ID and OD changes in tubing for catheters. 1

From Conventional to Robotic to Telesurgery—Stay Tuned

As micro extruded parts and devices continue to shrink in size, and MIS procedures become more common, the surgical skills required for such operations continue to ramp up. While smaller implantable devices are hugely beneficial because they require smaller, less invasive holes, the smaller devices also pose increasingly difficult challenges for even the most skilled human surgeon’s hands. So much so that robotic surgeries for a range of surgical implants could one day become the norm.

Recognizing the potential role of robotic surgery, the leaders in this space are stepping up device design efforts with robotic platforms in mind. These companies recognize that while they might be able to invent and develop increasingly sophisticated devices, such innovations require skilled surgeons to successfully implant them. Therefore, robotic-surgery platforms could level the playing field.

There is also an increasing use of robotic platforms at healthcare facilities worldwide. For example, the Golden Jubilee National Hospital in Clydebank, near Glasgow, Scotland, recently announced its use of a Mako robot by Stryker Corp., Kalamazoo, MI, for knee replacement surgery to ensure greater implant accuracy. 2

Micro extrusion processing performed below the submillimeter (0.004 in.) range employs highly modified equipment featuring innovations in extrusion head, tool, and screw designs. (Credit: Trelleborg)

At Excelsior Springs Hospital in Excelsior Springs, MO, where a roboticassisted surgery program relies on the da Vinci Xi Surgical System by Intuitive Surgical Inc., Sunnyvale, CA, Dr. Douglas Desporty, surgeon, sings its praises. “Although I was initially skeptical,” he says, “I became fully vested after seeing impressive patient satisfaction results and less need for post-operative narcotics. Not only are general surgeons embracing the robotic results, other specialists, including urologists and gynecologists, are utilizing the system with similar outcomes.”3

And at Corindus Vascular Robotics, Inc. in Waltham, MA, a joint project with the Mayo Clinic in Rochester, MN, serves to pretest “telestenting” procedures in hopes that these tests will lead to viable telesurgical procedures. While for now a Mayo Clinic doctor will be in the next room if needed, it is possible that remote procedures with doctors located miles away from the action could become a reality for rural patients without ready access to specialized healthcare. 4

As innovations in micro extruded parts, implantable devices, and robotic platforms expand the benefits of MIS, interest in robotic surgery soars. According to IDTechEx’s recent report, “Innovations in Robotic Surgery 2020–2030,” “Investments in companies operating in this space have skyrocketed since 2016, recording an increase of over 300 percent in three years, and total investment to date has reached $1.36 billion.”5

With such a growth curve, it is safe to say that robotic surgeries are now viable options, and it may not be too long before the same is said of telesurgeries. As this important healthcare chapter unfolds, makers of micro parts and devices will be central to the story.

Stay tuned.


  1. D. Sanchez, “Reducing Risk with Geometric Transition Extrusion,” Medical Design Briefs, Vol. 9, No. 11, November 2019.
  2. NHS Hospital Begins Using Robotic for Knee Replacement Surgery,” Med-Tech Innovation, Dec. 11, 2019.
  3. The da Vinci Xi Surgical System,” Excelsior Springs Hospital.
  4. C. Newmarker, “Report: Mayo Clinic to Try Corindus Telestenting,” MassDevice, Dec. 23, 2019.
  5. Ivan De Backer, “Innovations in Robotic Surgery 2020–2030: Technologies, Players & Markets,” IDTechEx report.

This article was written by Dan Sanchez, Product Manager, Trelleborg Healthcare & Medical. For more information, visit here .