Vietnamese doctor develops bionic legs for disabled people

The bionic leg developed by the research team of Dr. Tran Minh (28 years old) weighs only 3 kg, helping amputee patients walk comfortably as usual.

The Utah Bionic Leg was started to be manufactured by Dr. Minh and his colleagues at HGN Lab, University of Utah (USA) in 2017. The leg is designed to weigh 3 kg, half of other types of prosthetic legs on the market. The length of the leg can vary depending on the height of the user and the length of the amputated limb. The device is designed to effectively support movement for all users weighing less than 125 kg.

Dr. Lukas Grabert, a member of HGN Lab, said that the group studied the mechanism of human legs and found that to move quickly and efficiently, it is thanks to passive momentum. That is, when inertia and gravity interact with the limbs while moving. Based on this mechanism, the group designed a transmission system in the bionic leg, which helps passively adjust the configuration of the leg when moving.

The product consists of two main parts: the knee joint and the ankle and foot joint. Each joint is equipped with an electric motor, sensors, microprocessor, battery system, circuitry and artificial intelligence (AI). These parts work together to perform all the main motor functions of the leg such as: walking, standing up, sitting down, moving on slopes and stairs.

The legs are designed with a specialized smart drive system in 3 parts. The knee joint has the function of optimizing operating capacity and saving battery. The ankle/foot joint has a drive system developed based on the tendon system in the human foot. Finally, the ankle/foot joint is connected to the toe joint by a spring system to help the patient move naturally and balance on many different road surfaces and weather conditions.

As the user moves, the sensors and systems equipped in the bionic leg will transmit information to the AI processor about the activity status and level of movement. The system will determine the user's intention to provide the appropriate level of support. The product also has a low-power mode for long periods of time, so the user can maintain movement without losing strength.

Dr. Tran Minh assembles bionic legs in the lab. Photo: NVCC

Dr. Minh said that all prosthetic products need to be installed in the hospital so that doctors and specialists can adjust them according to the patient's height and weight and provide instructions for safe movement.

According to the research team, the prosthetic legs currently on the market are designed as shock absorbers and are mechanically passive. That is, they do not have motors and the flexibility of movement that an able-bodied person has. These products require patients to be in good physical condition and take a long time to get used to.

The Utah bionic leg overcomes the limitations of traditional prosthetic legs. HGN Lab engineers designed the mechanical details and electrical circuits, then machined them according to requirements. These details were sent to the lab for assembly, software installation, and fine-tuning to optimize functionality. "With the Utah bionic leg, the user will get used to it faster because of the power assist system," said Dr. Minh.

The device was tested on amputee patients. Photo: Research team

Having tested the device on more than 20 patients since 2020, the team says the response from users has been positive. Many patients can perform essential movements that they cannot do with conventional prostheses, such as going up and down stairs or sitting up without assistance.

"The team's product is the world's first bionic leg that helps a person with both limbs amputated walk comfortably," said Dr. Minh. The research's test results were published in prestigious scientific journals such as Science, Scientific Report and IEEE Transactions.

Professor Tommaso Lenzi, University of Utah, instructor, commented that scientists have been researching prosthetic limb technology since the 1970s but have not achieved their goals. Currently, mechatronic technology has advanced as microprocessor batteries and electric motors are becoming faster, more compact and lighter. Taking advantage of technological developments and discoveries about passive dynamics, the Utah bio-prosthetic leg product of the group "with its compact size, will help patients with amputated legs to move independently and freely pursue their goals in life", Professor Tommaso Lenzi assessed.

Dr. Minh said that the team continues to test the feasibility of the Utah prosthetic leg when users use it at home for a long time. Currently, HGN Lab is collaborating with Otto Bock, the world's largest prosthetic limb manufacturer based in Germany, to mass-produce the Utah bionic leg into a medical product for users in the shortest time, with a selling price equivalent to traditional prosthetic leg models.

Dr. Tran Minh was born and raised in Hanoi . Minh completed high school at Hanoi - Amsterdam High School for the Gifted in 2013. He went to the US to study for a bachelor's degree in mechanical engineering at the University of Utah and received his doctorate in May 2023. In 2015, Dr. Minh began designing robots with a main research area of flexible and high-performance limb joints. He is currently a design engineer for Agility Robotics, a company specializing in manufacturing robots in the US.

vnexpress.net