Advances in robotics promise performance boost in prosthetic hands

October 27, 2014

Work on the design, development and testing of next-generation prosthetic hand technology by a team of researchers from Arizona State University, Mayo Clinic and the Italian Institute of Technology will proceed with support from the National Institutes of Health (NIH).

Neurophysiologist Marco Santello, physician Karen Andrews and roboticist Antonio Bicchi are collaborating on a project that employs new advances to simplify the control of grasping movements by a robotic hand. Marco Santello robotic hand Download Full Image

Santello is a professor and director of the School of Biological and Health Systems Engineering, one of ASU’s Ira A. Fulton Schools of Engineering.

Andrews is the director of Amputee Rehabilitation Services in the Department of Physical Medicine and Rehabilitation and director of the Vascular Ulcer/ Wound Healing Clinic in the Gonda Vascular Center at the Mayo Clinic in Rochester, Minnesota.

Bicchi is a professor of robotics at the University of Pisa and a senior scientist at the Italian Institute of Technology (IIT) in Genoa.

Their progress has earned an NIH R21 grant that will provide them approximately $400,000 over two years to pursue improvements in artificial hand technology.

Despite advances in prosthetic hands, current technologies still provide only limited functionality and lack adequate grasping capabilities, Santello said.

Costs, the weight of devices, durability and maintenance are additional drawbacks to existing hand prostheses, he said.

To improve the technology in each of these areas, a new prosthetic hand will be fashioned using designs originated by Bicchi and his collaborators at IIT and the Italian Centre for Health and Safety at Work (INAIL). They have been developing a prosthetic hand based on the innovative robotic hand called the Pisa/IIT SoftHand, developed by the researchers at the University of Pisa and IIT.

The design of the SoftHand is based on “soft synergies” that capitalize on human hand synergies and novel “soft” robotics technologies.

The Softhand was initially designed and used for robotics applications, but preliminary data indicate it can be adapted to enable people to grasp and manipulate a wide variety of objects with minimal training.

The key is a design based on natural finger coordination patterns, making it easier to control.

Typically, prosthetic hands require motors to control the movement of each joint. In contrast, the SoftHand uses a technique described as underactuation, meaning that one motor can control movement in more than one joint. That capability provides for more simplified and user-friendly hand motion and reduces the weight of the device.

The patterns of finger motions that can be generated by the SoftHand are based on experimental observations by Santello and his colleagues of how multiple joints in the hand move together. The SoftHand also features compliance control, making it effective for both delicate and forceful manipulation tasks.

The ASU, Mayo and IIT research project will focus on the adaptation of the SoftHand to people with amputations, with the aim of providing clinical feedback that will guide design modifications of the SoftHand to develop new myoelectric prosthetic hands.

Myoelectric pertains to the electrical impulses generated by muscles. The impulses can be amplified and used to control artificial limbs by activating the motors of prosthetic devices.

“We expect that by using a very small number of extrinsic hand muscles in the forearm, people with a transradial amputation (an amputation below the elbow) will learn to use the new myoelectric hand and perform grasp and manipulation tasks to a greater level of proficiency relative to what they can do with the prosthetic hand they are now using,” Santello says.

Myoelectric hands are controlled by the users’ signals associated with tensing and relaxing of their extrinsic muscles individually or together.

Electrodes in contact with the skin on the forearm will pick up electrical signals and transmit them to a controller. The unique feature of the SoftHand is that the controller processes and analyzes the electrical signals and maps them to one actuator (a motor) that moves multiple joints in a coordinated fashion.

The research team will analyze the mapping of electrical signals to specific hand postures and forces, as well as the extent to which grasping and manipulation performance can benefit from adding force-feedback mechanisms to the SoftHand.

The project will quantify the functional capabilities of the SoftHand for prosthetic applications. Biomechanical tests and movement tasks used by clinicians will allow researchers to assess the functionality of the new device on individuals with limb loss.

Santello and his collaborators believe that users of the SoftHand will learn to use it to perform grasp and manipulation tasks more easily than with current devices.

They expect the outcome of the project to provide the basis for further refinement of design and development of a high-performance prosthetic hand that has superior functional capabilities and could be produced at a comparatively low cost.

Mayank Prasad contributed to this article.

Joe Kullman

Science writer, Ira A. Fulton Schools of Engineering


Joint venture expands ASU-China partnership

October 28, 2014

ASU announces Biodesign Center in China

Arizona State University and China’s Shandong University announced a joint venture Tuesday to focus on “bio-inspired” cancer and vaccine research, water and air purification systems and advanced explorations of nanotechnology. President Crow in China President Crow in China Download Full Image

ASU President Michael Crow announced the collaboration on a Biodesign Center to be based in the Chinese port city of Qingdao. It is part of ASU's continued effort to deepen and expand research and related initiatives across China.

“This cooperative effort is what being the ‘New American University’ is all about: engaging globally and deeply with top research institutions in China to achieve amazing things, not only now, but in the many years to come,” Crow said.

Shandong University’s Biodesign Center will be modeled after the ASU Biodesign Institute in Tempe, where researchers work to develop commercially viable health care, sustainability and security solutions by studying how the natural world is designed and how it functions.

“By joining forces with Shandong University, we wish to establish a major Chinese expansion of this vision as part our strategic, long-term commitment to using nature’s design rules to meet some of the world’s most pressing problems,” said Raymond DuBois, executive director of ASU’s Biodesign Institute.

The announcement comes in the middle of a weeklong trip to China for Crow and an ASU delegation that includes Sethuraman Panchanathan, ASU’s senior vice president for Knowledge and Enterprise Development; Richard T. Myers, treasurer of the Arizona Board of Regents; and Denis Fred Simon, Crow’s senior adviser for China and Global Affairs. Simon is a 30-year veteran of working in China on technology and business issues.

In addition to Qingdao, Crow visited China’s capital Beijing Monday, and will travel to western China to the city of Chengdu later this week. There, he will meet with the president of Sichuan University to discuss a new joint training program between Sichuan and ASU’s School of Public Affairs, focusing on disaster and crisis management.

ASU works with more than 10 of China’s top universities as well as the Chinese Academy of Sciences and the Ministry of Science and Technology.

The university’s programs in China include the Global Decision Theater Alliance, the Center for American Culture and an executive MBA program under the auspices of the Chinese Ministry of Finance.

ASU also sponsors international accelerated degree programs which allow students from China to complete three years of undergraduate work before coming to ASU for two years of graduate study. They earn both a bachelor’s and master’s degree at the end of the program.

And there are more than 3,000 Chinese students at ASU, representing the largest contingent among the university's international students.

ASU and Shandong University are evolving a long-term strategic, academic and collaborative research and development partnership. The Biodesign Center in Qingdao will allow experts at both universities to collaborate in research on chronic disease, the search for new sources of energy and ways to help people affected by natural disasters or acts of war.

“Shandong University is proud of the close, long-term cooperation we have formed with Arizona State University over the years,” said Shandong University President Zhang Rong. “And we are only just beginning. Shandong University looks forward to future collaboration with ASU across a broad spectrum of subject areas and cooperative formats.”

That collaboration extends to the Chinese city in which the Biodesign Center will be located: Qingdao.

“We have determined that the two core focal points for Qingdao's future development will be design and biosciences,” said Qingdao’s Vice Mayor, Wang Guangzheng. “The development of the ASU-SDU strategic partnership in biodesign fits perfectly with the city's key priorities.”