Cast Urethane Case Study: The Titan Medical Patient Cart

By <a href="https://mfg.trimech.com/author/trimech/" target="_self">TriMech Marketing</a>

By TriMech Marketing

Posted on October 12, 2017

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 cos-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.

Titan Medical Cart

Titan Medical Cart

The Cart Design

Ximedica LLC (Providence, RI) was chosen by Titan Medical to be their principal development partner. Ximedica is an engineering and development firm that takes clients’ product ideas from initial concept to 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 for help.

The first patient cart was required in ten weeks. The unit, which would be used in trials and studies, had over 50 unique parts with the largest ones being 40 inches.

Cutting Costs and Upgrading Materials

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 believed cast urethane prototypes would be the best way to meet the deadline, achieve the required material properties, and significantly reduce costs. The rubber mold patterns required very high accuracy and would be 3D-printed with SOMOS NeXT material on InterPRO’s large-frame SLA system.

After researching hundreds of available urethane materials, InterPRO determined that most of the parts could be cast using PTM&W’s PT8902 and PT8976 materials. These rugged materials offered the right balance properties, cure speed, accuracy, and cost. Another advantage was that inserts needed for assembly could be cast into the molded parts. A smaller number of the final production parts would be 3D-printed on SLA using high-impact SOMOS NeXT material.

Ximedica approved the recommendation and InterPRO’s team began working around the clock.

Titan Cast parts

Titan Cast Parts

“More than 50 unique parts needed to be produced using production grade materials, with very tight tolerances in a very short amount of time. It was a significant challenge, but we felt confident it could be accomplished.”

— Dan Straka, TriMech Advanced Manufacturing General Manager

InterPRO Gets to Work

Over 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, and 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 ten weeks, the day before Thanksgiving. 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 gynecological, urological, and colorectal procedures upon receiving appropriate regulatory clearances.

“Ximedica’s team was exceptional to work with. The quality of their CAD data allowed InterPRO to focus on delivering high-quality parts that fit together perfectly. The patient cart project highlighted the capabilities of urethane casting and 3D printing to deliver fast, functional parts.”

— Dan Straka, TriMech Advanced Manufacturing General Manager

Article by <a href="https://mfg.trimech.com/author/trimech/" target="_self">TriMech Marketing</a>

Article by TriMech Marketing

TriMech provides thousands of engineering teams with 3D design and rapid prototyping solutions that work hand-in-hand, from sketch to manufacturing. InterPro became a part of TriMech Solutions LLC in 2021.