Motion Control Application – Robotic Rib Spreading Tool to Help Patients Hurt Less and Heal Faster!

March 28, 2023 Editor-Publisher

Motion Control – Medical Application

One advanced technology company is taking on the challenge of developing hand-held, robotic surgical instruments to help patients hurt less and heal faster. High torque maxon motors ensure jerk-free movement of the tool.

Fall River, MA — It may sound unbelievable, but some tools that physicians use to perform invasive surgery were originally developed in the 1930s and have gone through minimal updating since.

Most often, these tools have been efficient enough to do the job, even if patients took a long time to heal.

This is especially true when a surgeon has to enter the chest cavity for heart or lung operations. To date, there are two primary methods used to open a space large enough for a doctor to work inside the chest: a thoracotomy or a sternotomy.

The thoracotomy is where an incision is made between two ribs to gain access. For a sternotomy the surgeon saws through the sternum and then spreads it apart. In both cases, the surgeon pries apart the ribs or sternum using a hand-cranked, stepping mechanical jack called a thoracic retractor. Large forces are needed to spread the ribs. In fact, the Physcient team discovered that the forces necessary to separate the ribs are roughly equal to the weight of the person being operated on, which means that using a thoracic retractor can result in broken bones, crushed nerves, wrenched joints, and torn ligaments. All of these factors offer adverse post-surgical effects that can be ongoing.

Physcient (Durham, NC) has developed technologies that are expected to greatly reduce the damage of thoracic retraction. “Two of the concerns we ran into,” said Chuck Pell, co-founder (with Hugh Crenshaw) of Physcient, “were that we had to maintain the same footprint as other thoracic retractors being used in the operating room today, plus we had to be able to sterilize the tool repeatedly, to be used for literally hundreds of cycles.” The company’s Assuage™ Smart Retractor™ was designed to apply technology to solve a longstanding problem without changing surgeons’ procedures.

According to Mr. Pell, “We both [he and Dr. Crenshaw] studied biomechanics, and it is that understanding of how creatures move that we use to translate into technology. We recently turned that knowledge to surgical tools, and are finding it very interesting. Many of the tools used in surgery today were invented prior to biomechanics becoming a mature science.”

The National Heart, Lung, and Blood Institute says that over half a million heart surgeries are done every year. Add to that number another hundred thousand lung surgeries, and the need for better tools quickly becomes apparent. Because of the antiquated design of thoracic retractors being used today and the number of surgeries being performed, the incidents of rib fractures has continued to increase.

Powerful drives for soft movements

maxon manufactures a complete line of motors from 4mm motors to 90mm motors for a wide variety of applications. They are electronically commutated for minimal electrical noise. The company’s DC brushless motors have no mechanical brushes to wear out, which allows them to provide extremely long motor life. By being designed using high-grade, preloaded ball bearings an additional benefit in longevity is added to the motor. maxon motors provide a low profile design ideal for applications requiring a small footprint.

The Physcient Assuage™ Smart Retractor™ takes into consideration the physics of bone and tissue. As with most cardiothoracic research, tests were run on pigs, which are biomechanically similar to humans. The Physcient team built a prototype that used two rows of curved metal fingers, meant to cradle a single rib. As the retractor automatically spreads the ribs, sensors provide feedback to the maxon motor, providing smooth opening. In the experiments, Physcient’s retractor greatly reduced tissue trauma, reduced pain, improved breathing, and resulted in better overall recovery.

Once the team at Physcient produces the Assuage™ rib spreader, they plan to look into other medical equipment that hasn’t changed over many years. Their aim has always been patient-oriented through offering the right tools for the surgeons, and plans to automate and upgrade the entire surgical toolkit.

Author: Deb Setters maxon precision motors; Anja Schütz, © maxon motor ag Schütz Anja

Downloads

PDF – Robotic Rib Spreading Tool to help patients hurt less and heal faster.

About Maxon

In this motion control application, the Swiss specialist for quality drives maxon is a developer and manufacturer of brushed and brushless DC motors, as well as gearheads, encoders, controllers, and entire mechatronic systems. maxon drives are used wherever the requirements are particularly high: in NASA’s Mars rovers, in surgical power tools, in humanoid robots, and in precision industrial applications, for example. To maintain its leadership in this demanding market, the company invests a considerable share of its annual revenue in research and development. Worldwide, maxon has more than 3000 employees at nine production sites and is represented by sales companies in more than 30 countries.

Maxon is a developer and manufacturer of brushed and brushless DC motors, as well as gearheads, encoders, controllers, and entire mechatronic systems. With over 50 years of experience in drive technology, maxon works closely with engineers designing high-tech innovations. maxon drives are used wherever the requirements are particularly high: in NASA’s Mars rovers, in surgical power tools, in humanoid robots, and in precision industrial applications. Worldwide, maxon has more than 2800 employees at nine production sites and is represented by sales companies in more than 30 countries. www.maxongroup.com

Contact maxon for more details https://support.maxongroup.com/hc/en-us/requests/new

Comprehensive documentation and software are included with every delivery, and are also available for you to download from our website at www.maxonmotor.com.