Cast Urethane Case Study: The Titan Medical Patient Cart


Recent reports show that the market for surgical robotic systems is expected to grow from $3.2B in 2014 to $20B in 2021. However, the minimally invasive surgery technologies currently available involve serious challenges.

These include limited capability, long setup times, and huge floor space requirements. Due to the very high cost of entry, the current robotic technologies are also cost prohibitive for most secondary and tertiary hospitals.

Titan Medical Inc. is a Canadian company focused on addressing these challenges. Their company has developed the SPORT™ Surgical System, a computer-assisted robotic surgery system that is significantly more agile, versatile, easy to use, and affordable than existing robotic solutions.

Titan’s SPORT™ Surgical System is being developed as a versatile, single-incision robotic surgery platform.  It offers a high definition 3D monitor, multi-articulated instruments for increased precision and a shorter learning curve.  Seated at the ergonomic open workstation, a surgeon would be capable of performing a broader range of extremely delicate surgical procedures.

cast urethane production

The Challenge

Ximedica LLC (Providence, RI) was chosen by Titan Medical to be their principal development partner. Ximedica is an engineering and development firm that takes customers’ product ideas from an initial concept to a product launch.  Ximedica focuses exclusively on the development of medical devices.

When Ximedica was asked by Titan Medical to design and deliver three complete engineering verification units of their SPORT™ Surgical System patient cart, they contacted InterPRO.

The first patient cart was required in 10 weeks.  The unit, which would be used in animal trials and user testing trials, had over fifty unique parts with the largest ones being 40 inches.

gallery-cu-2

The Cast Urethane Solution

Ximedica was considering using 3D printing to produce all the parts.  Calculating the printing time showed this would take longer than required even with InterPRO’s nine SLA and Fortus 3D printers. InterPRO decided that urethane casting would be the only way to meet the deadline and achieve the required material properties.  It would also significantly reduce costs.

After researching hundreds of available urethane materials, InterPRO recommended PTM&W’s PT8902 and PT8976 materials because of their engineering properties, cure speed, accuracy and cost.

“Switching to cast urethane allowed us to deliver a better product – both faster and less expensively than 3D printing would have allowed,” said Dan Straka, General Manager at InterPRO. “We chose PTM&W materials because they are great for creating high impact, production-grade components.”

Inserts needed for assembly could be cast into the molded parts, and a small number of the final parts would be 3D printed. Ximedica approved the recommendation and InterPRO’s team began working around the clock.

Printing, Building RTV Molds, Assembling and EMI Shielding

ximedica titanOver 200 hours of machine time were needed to 3D print the mold masters.  Due to the large part size, several SLA patterns had to be joined to create mold patterns.  After assembly and hand finishing, as well as confirmation that all dimensions were correct, the printed parts were ready to be used as master patterns.

Building the RTV molds consumed over 3000 pounds of silicone. Most of the cast parts were created using PT8902 material, which offers excellent impact strength.  EMI shielding and a textured painted finish were applied to finish the parts. For softer parts a UV-stable, Shore A 80 material was used.

InterPRO delivered the first completed unit in 10 weeks. After completing their part inspection, Ximedica and Titan Medical increased their order from three to five carts.  These SPORT Surgical System patient carts are now being used to demonstrate Titan Medical’s technology at conferences and support the continued development of the surgical system to enable it to be used for general, gynecological, urological and colorectal procedures upon filing for and receiving appropriate regulatory clearances.