Leech therapy is the practice of introducing biological leeches to induce blood flow through the region.  The primary function of the leech is to prevent blood pooling and reduce pressure. This is accomplished naturally through the feeding process of leeches that creates a small incision, secretes an anticoagulant, and reduces the excess fluid.

University of Utah School of Medicine surgeon, Dr. Jay Agarwal, assistant professor in the Department of Surgery, Division of Plastic Surgery and Huntsman Cancer Institute Investigator, is interested in leech therapy for some of his patients.  Agarwal proposed the idea of a reliable functioning mechanical leech device to Dr. Bruce Gale, associate professor in the Department of Mechanical Engineering and director of the Center of Excellence for Biomedical Microfluids at the University of Utah.  Gale felt it would make a nice undergraduate senior capstone project.

The University of Utah Mechanical Leech mimics the functions of the biological leeches used in leech therapy. The Mechanical Leech is currently about 1” (25mm) in diameter plus additional tubing, and will eventually offer numerous size variations to accommodate the doctors’ needs. The primary customers for the Mechanical Leech are intended to be doctors and surgeons.

The completed device will provide a suitable replacement for the biological leech by reducing excess fluidic pressure and injecting an anti-coagulant into patients. In addition to eliminating a patient’s adverse reaction to biological leeches, a Mechanical Leech will be able to provide more consistent, controllable performance over its parasitic counterpart, making it more desirable to doctors and surgeons to use during therapy.

“Mechanical Leech was in my top five project choices, but I didn’t really know what the project would be like; the title is what caught me,” says Jessica Kuhlman, mechanical engineering senior. “We were going to be solving a real world problem and that is the main reason I wanted to go into engineering.  After the team got together, we met with Dr. Agarwal, who was crucial to our coming up with the design.  Having a surgeon that has used leeches and be able to tell us how the device needs to function was very helpful.  He was also a great resource regarding our potential future customers and what would make the device better and, from the doctors’ view point, more user friendly.”

“After coming up with the conceptual design,” commented Jessica, “we were able to create 3D printed designs and test them to the specifications that we had created. As our design progressed and we created multiple iterations, it seemed as though our design could be a viable option for the medical community.   We had a lot of help along the way from our faculty advisor Professor Gale and senior design teacher, Dr. Shad Roundy, assistant professor in mechanical engineering. They were able to direct us on the path to success with our project.”

Victor Walker, mechanical engineering senior, agreed that, “Dr. Gale was an incredible advisor to work with. He provided great insight to our project and steered us in the right direction when we were lost. It was very beneficial to work with him as well because he was able to tell us what was expected on our presentations throughout the semester.  I was initially attracted to the project because of the fluid mechanics part of it. I am getting a Fluid Mechanics emphasis with my degree and I wanted my senior design project to highlight that. Additionally, I was very intrigued that this project was tied into the medical field. I had never had experience within that field and thought it would be very interesting to try it out.  I was overwhelmingly pleased with what our team was able to do with the project.  We put a ton of hard work into our project and to see it pay off was incredible.”

“As for myself,” say team leader Andy Thompson, mechanical engineering senior, “what attracted me to this project was the opportunity to be part of the development of a medical device.  My background is in manufacturing and I have spent some of that time manufacturing medical devices, so it was very interesting to be part of a medical device from the beginning.

One of the biggest problems we faced was actual testing of the device.  Testing on live tissue is not really an option so we had to figure out ways of verifying different aspects of the device in other ways.  Testing on “fleshy” type fruits to verify the diffusion and removal of the injected liquid solved this.  Another was to pump Heparinized bovine blood through the device for several days to verify that the areas of fluid flow would not become clogged. Dr. Gale worked with us in a great advisory capacity, he helped us when we were starting to move in the wrong direction, but left us to fight out the details and learn for ourselves.”

“The thing that is most rewarding about this project is the scope of the project,” noted Scott Ho, mechanical engineering senior. “We were able to go from a product and field research stage to exploring commercialization and really consider all aspects of the engineering process. It was a project that had a practical application in the medical field and our role in the project encompassed the entire device, not just a small section of a system.  At Design Day, typically the larger projects draw more attention because they are more tangible and ‘mechanical’,  but I think the immediate and practical application of our device was a big draw, especially for Boeing and other people coming from an industry background.”

On April 12, the Mechanical Leech team finished as the runner up at the Bench to Bedside competition at the Point in Huntsman Cancer Institute and received a $10,000 cash award. Ho noted that, “Our participation with the Bench to Bedside competition pushed us to take the device further than the basic design and verification that most engineering projects reach. We really had to explore end-product market scenarios and the viability and customer demand for the mechanical leech. For me, the positive attention we received at the Bench to Bedside competition and at Design Day was completely unexpected. At Bench to Bedside, we were the only mechanical engineers and the majority of the teams were composed of medical school or bioengineering students and others with more experience in the medical field.”

Left to right: University of Utah Mechanical Leech Mechanical Engineering Seniors: Andy Thompson, Scott Ho and Ladan Jiracek. Team members not pictured Jessica Kuhlman and Victor Walker.

“We were also recognized by the judges that came from Boeing to our April 15, Mechanical Engineering Design Day, which was held in the Student Union Ballroom, as one of the top three projects,” says Ladan Jiracek, mechanical engineering senior.  “I was personally attracted to this project because of my background. I have an education and work experience in the field of microsystems. I had actually taken a class from our advisor, Dr. Gale, in the field of microfluidics a few years ago. This was the main reason that even after the teams was set in the beginning of Fall semester, that I fought hard to get on the Mechanical Leech team.”

“As for the award,” noted Ladan, “it was not expected at all. When we entered the Bench to Bedside competition it was mostly to go through the learning experience. However, when we were presenting many judges complimented us om our project. We also had people bring others specifically to our presentation to show how good it was.  Working with our advisor was a very pleasant experience. Although he is a very busy professor with many projects, he was able to make time for us and to give us helpful advice on what we needed to accomplish and improve upon.”

The Mechanical Leech undergraduate project was one of 23 senior design projects showcased during the Department of Mechanical Engineering Design Day held on April 16, 2013, in the Olpin Union Building.  The Department of Mechanical Engineering at the University of Utah is committed to providing students with broad-based, rigorous and progressive education.  By combining state-of-the-art facilities with renowned faculty, the department provides an education that gives students the necessary skills to become the next generation of innovators.