Toyohashi University of Technology

Researchers have developed a virtual robotic limb system which can be operated by users' feet in a virtual environment as extra, or supernumerary, limbs. After training, users reported feeling like the virtual robotic arms had become part of their own body. This study focused on the perceptual changes of the participants, understanding of which can contribute to designing real physical robotic supernumerary limb systems that people can use naturally and freely just like our own bodies. Research teams at the University of Tokyo, Keio University and Toyohashi University of Technology in Japan have developed a virtual robotic limb system which can be operated by users' feet in a virtual environment as extra, or supernumerary, limbs. After training, users reported feeling like the virtual robotic arms had become part of their own body. This study focused on the perceptual changes of the participants, understanding of which can contribute to designing real physical robotic supernumerary limb systems that people can use naturally and freely just like our own bodies. What would you do with an extra arm, or if like Spider-Man's nemesis Doctor Octopus, you could have an extra four? Research into extra, or supernumerary, robotic limbs looks at how we might adapt, mentally and physically, to having additional limbs added to our bodies. Doctoral student Ken Arai from the Research Center for Advanced Science and Technology (RCAST) at the University of Tokyo became interested in this research as a way to explore the limits of human "plasticity" -- in other words, our brain's ability to alter and adapt to external and internal changes. One example of plasticity is the way that we can learn to use new tools and sometimes even come to see them as extensions of ourselves, referred to as "tool embodiment," whether it's an artist's paintbrush or hairdresser's scissors. To explore these concepts in action, teams at the University of Tokyo, Keio University and Toyohashi University of Technology in Japan collaborated to create a virtual robotic limb system. They then asked participants to perform tasks in virtual reality (VR) using the virtual limbs. "We investigated whether virtual robotic arms, as supernumerary limbs, could be perceived as part of one's own body, and whether perceptual changes would occur regarding the proximal space around the robotic arm," said Arai. Participants wore a head-mounted display to give them a first-person view of their own arms represented in VR, as well as the additional virtual robotic arms. They then had to perform tasks using only the virtual robotic arms, which were controlled by moving their toes. Tactile devices returned sensations from the virtual robotic arms to the tops and soles of their feet when they touched an object, like a virtual ball. Once the participants learned how to use the virtual system, they reported feeling like the virtual robotic arms had become their own extra arms and not just extensions of their real arms or feet. "The scores of subjective evaluation statistically became significantly higher for 'sense of body ownership,' 'sense of agency' and 'sense of self-location,' which are important measures of embodiment, where the supernumerary robotic limb is able to become part of the body," said Arai. The team also found that the participant's "peripersonal space" (the area around our bodies which we perceive as being our personal space) extended to include the area around the virtual robotic arms. As Arai explained, "We succeeded in capturing the positive association between the perceptual change in visuo-tactile integration around the supernumerary robotic limbs (peripersonal space), and the score change of subjective evaluation of feeling the number of one's arms increased (supernumerary limb sensation)." Next, the team wants to look at the potential for cooperative behavior between participants' own arms in virtual reality and the virtual robotic arms. "Investigating the mechanisms and dynamics of the supernumerary limb sensation reported here from the standpoint of cognitive neuroscience will be important in exploring human plasticity limits and the design of supernumerary robotic limb systems," said Arai. The hope is that by understanding the perceptual changes and cognitive effort required to operate a supernumerary robotic limb system in VR, this will aid in designing real-life systems in future which people can use naturally just like their own body.

The collaboration developed a simple, high-sensitive biotechnology and semiconductor technology that detects the SARS-CoV-2 virus The new biosensor detects SARS-CoV-2 spike protein. (Credit: Joseph Mucira from Pixabay.) Tokai University, Toyohashi University of Technology and Chubu University, in partnership with automotive components manufacturer DENSO, have developed a new biosensor for detecting SARS-CoV-2. The three Japanese universities and DENSO have been jointly working to develop clinical testing equipment that facilitates sensitive and rapid detection of viral infectivity. Japan’s Agency for Medical Research and Development (AMED) has supported the project. DENSO intends to advance the development to practically apply the testing solution for early diagnosis of infectious diseases, to help limit the spreading of the virus. According to the company, early diagnosis and isolation are important measures to prevent the spread of infectious diseases caused by viruses. PCR and antigen tests that are currently used to diagnose SARS-CoV-2, lack the capability of assessing the ‘virus infectivity’, the power of the detected virus to infect. The partnership aims to determine the infectivity of SARS-CoV-2 and offer novel tests that have a sensitivity of PCR tests and simple antigen tests. Unlike PCR tests and antigen tests, the biosensor detects spike protein of the virus using a semiconductor sensor and aptamer, said DENSO. Aptamers are peptide molecules that bind to a specific target molecule, and are easy to design and can be mass-produced rapidly. The semiconductor sensor can quantitatively measure the viral load by using electrical signals, and the technique is being used for the first time in the world. Also, the sensor is expected to determine the status of infection and confirm the efficacy of treatment with high accuracy. Furthermore, the universities and DENSO have sought to prevent the spread of SARS-CoV-2 infection by further developing the technologies that have been refined through the project.

KARIYA, Japan, Oct. 21, 2021 /PRNewswire/ -- Tokai University, Toyohashi University of Technology, Chubu University, and DENSO Corporation have been developing testing equipment to detect SARS-CoV-2 with support from the Japan Agency for Medical Research and Development (AMED)*1. Universities and DENSO announced today that the group has succeeded in developing a biosensor based on a new mechanism and detecting SARS-CoV-2. The group will accelerate the development toward practical application to contribute to early diagnosis of infectious diseases, which is a key factor in limiting virus' spread. To prevent the medical system from being overwhelmed due to viral infectious diseases, it is essential to prevent the spread of viruses by early diagnosis and isolation. At present, PCR tests*2 and antigen tests*3 are used for the diagnosis of SARS-CoV-2. However, these tests cannot evaluate "virus infectivity," which indicates the power of the detected virus to infect. PCR tests are characterized by its high virus detection sensitivity, but effort of sample pretreatment process imposes a high workload on medical professionals. Meanwhile, antigen tests are simple, but the detection accuracy varies. There has been growing demand for a high-sensitivity and simple detection method to evaluate viral infectiousness. The universities and DENSO have been developing a biosensor for clinical testing equipment to enable high sensitive and quick quantitative detection of viral infectivity. Unlike PCR tests and antigen tests, the biosensor detects the spike protein*4 on the virus surface, which triggers infection, by using a semiconductor sensor and aptamer.*5 The group has succeeded in developing highly sensitive detection of SARS-CoV-2 with high sensitivity by using this technique for the first time in the world.*6 The semiconductor sensor can quantitatively measure the viral load by using electrical signals. Thus, it is expected to be used to determine the status of infection and confirm the efficacy of treatment with high accuracy. An aptamer is small in size and binds selectively to various types of protein. It is also easy to design and can be mass-produced quickly, and so the aptamers can be used to detect unknown viruses. The goal of the development of the biosensor by the universities and DENSO is to determine the infectivity of SARS-CoV-2 and offer novel tests which have virus detection sensitivity equivalent to that of PCR tests and which is as simple as antigen tests. The group will enhance the basic technology and accelerate the development toward practical application. The universities and DENSO remain committed to preventing the spread of SARS-CoV-2 infection by harnessing the technologies that have been refined through the project. Glossary *1 AMED Universities and DENSO develop biosensor with the support of AMED, with the project called "Advanced semiconductor sensor-based biomolecule detection system towards diagnosis of infectious SARS-CoV-2" *2 PCR test A test for detecting genes in a virus. *3 Antigen test In a typical antigen test, the nucleocapsid protein in a virus is detected using an antibody. *4 Spike protein Protein on the virus surface. It has the function of binding to human cell receptors and triggers infection. *5 Aptamer An artificially synthesized nucleic acid molecule. It bonds with specific substances. *6 For the first time in the world World's first technology to detect the spike protein by using a semiconductor sensor and aptamer. Respective roles and comments ■ Tokai University From the viewpoint of infection control and laboratory physicians, we are eager to develop a system characterized by superb sensitivity and specificity and capable of quick diagnosis to determine infectiousness with simple operation. We offer advice on practical application and ensure accuracy management by using products, which are developed with world-leading engineering capabilities. ■ Toyohashi University of Technology We fabricated a semiconductor sensor capable of converting the viral load into electrical signals and supplied it to this project. The use of semiconductor technology makes it possible to distinguish viruses which cause very similar symptoms in a single test by using a sensor as small as a grain of rice. ■ Chubu University We prepared and supplied various types of viruses to evaluate the specificity of the semiconductor sensor. This biosensor is capable of quick detection of "infectious viruses" which cannot be determined by conventional methods such as PCR tests. Determination of the status of viral proliferation (that is, whether the viruses that have entered the body keep their infectivity or not) will clarify the timing when viral detection and/or isolation could be finished, and help infected individuals return to normal life. ■ DENSO Corporation We supplied biotechnology to detect viruses using a semiconductor sensor with higher sensitivity by taking full advantage of our expertise derived from R&D on detecting various viruses and biomarkers, which was conducted as part of advanced research to create a comfortable cabin space. We will accelerate the development toward practical application by leveraging biotechnology and semiconductor technology that have been refined through many years of operations.