Harvard Engineers Develop Robot to Treat Rare Birth Defect

Engineers from the Engineering Faculty at the University of Sheffield and Boston Children’s Hospital, Harvard Medical School have created a robot with the intention of treating a rare birth deformity.

The proposed technology can be implanted into the body of an infant to aid the treatment of esophageal atresia (EA), a defect that impacts the baby’s esophagus. EA is a congenital defect — meaning the issue arises before birth – and, in most cases, the upper esophagus ends and does not connect with the lower esophagus, preventing food from reaching the stomach.

Babies born with this disorder are also commonly diagnosed with tracheoesophageal fistula, which permits the flow of fluids into the airways, has the potential to interfere with breathing, and can only be repaired surgically.

The robotic implant, developed by Dr Dana Damian from the Department of Automatic Control and Systems Engineering at the University of Sheffield and her team from Boston Children’s Hospital, stimulates cells by using sensors to gently tug on tissue. It is a small device attached to the esophagus by a pair of rings while an incorporated motor assists the tissue growth. Two sensors — one to measure the tension and the tissue and another to measure tissue displacement – allow the robot to inspect the tissue and apply traction where needed.

Inspiration for the robot’s function comes via the Foker technique of correcting esophageal atresia, which is characterized by the manual slow pulling of tissue using sutures. Using this technique, the treatment of EA cases can begin in an infant’s first 3 months.

"Doctors have been performing the Foker procedure as they realised that tissue lengthening can be achieved by pulling on the tissue,” said Dr Damian in an article on ScienceDaily.com. “However, it is unknown how much force should be applied to produce tissue lengthening. Although the technique is one of the best standards, sometimes the sutures surgeons attach to the oesophagus can tear which can result in repetitive surgeries or scar tissue can form that can cause problems for the patient in the future.”

The implant is powered by a control unit which remains outside the body and is attached to a vest, allowing the patient to move around and interact with his or her parents while undergoing treatment. Doctors can monitor the patient without impacting daily routines, which was previously not an option, as patients typically needed to be sedated to repair the defect.

The design of the robot had to be soft and durable, air and water impermeable, abrasion resistant, non-corrosive, and able to be implanted for long-term treatment. Dr Damian was well-aware of the challenges her team would face as it prepared to create the blueprint for this potential therapy: "The biggest challenge we faced was to design a robot that works in a technology-hostile environment, and to develop a robust physiologically-relevant interaction with the tissue that promotes its growth when there are so many unknowns about the underlying mechanisms.”

"This is the first step in adaptive regenerative-based treatments of tissues,” she continued. “We have made a device that can provide long-term control of the tissue growth using on-board medical expertise. We further want to look at other tubular tissues, such as the intestine and the vascular system, to see if this sort of technology can be used to help with other conditions, such as Short Bowel Syndrome."

Technology capable of increasing tissue without the production of new tissue has been an unmet need throughout the bioengineering community for years. This new resource could be a step in the right direction as it pertains to understanding how mechanical stimulation assists in stimulating cells to multiply and grow.

"Increasing knowledge of how tissues respond to mechanical strain with the production of new tissue has been needed for a long while,” said Professor Sheila MacNeil, Professor of Tissue Engineering in the Department of Materials Science and Engineering at the University of Sheffield. "The development of this robotic implant is a breakthrough in applying the knowledge that tissues respond to strain with the production of new tissue in a practical and clinically useful manner."

References:

1. Dana D. Damian, Karl Price, Slava Arabagi, Ignacio Berra, Zurab Machaidze, Sunil Manjila, Shogo Shimada, Assunta Fabozzo, Gustavo Arnal, David Van Story, Jeffrey D. Goldsmith, Agoston T. Agoston, Chunwoo Kim, Russell W. Jennings, Peter D. Ngo, Michael Manfredi, Pierre E. Dupont. In vivo tissue regeneration with robotic implants. Science Robotics, 2018; 3 (14): eaaq0018 DOI: 10.1126/scirobotics.aaq0018
2. New Robot Can Help Treat Rare Birth Defect. Western Bank, Sheffield: University of Sheffield; January 18, 2018. sciencedaily.com/releases/2018/01/180118084351.htm. Accessed January 19, 2018.