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Is it possible to diagnose health from sweat? High-precision vital data analysis using "microsensors"

Professor Umezu, please tell us about your research area.

Umezu: I am involved in the research and development of medical and healthcare measuring devices and their analysis systems. My strength is that I simultaneously take a two-pronged approach to developing more accurate and miniaturized sensors and improving AI analysis functions,  and I aim to make more accurate judgments. The vital data that is analyzed is varied, including pulse waves, which can measure the stiffness and blockage of blood vessels, electrocardiograms, and brain waves.

Professor Shinjiro Umezu (Faculty of Science and Engineering)

For example, in the past, we worked on developing a system for the early detection of atrial fibrillation (a type of arrhythmia), which is considered to be a sign of cardiogenic cerebral infarction (※1). Because atrial fibrillation does not occur constantly, it is easily overlooked even during regular checkups, making it difficult to detect. Therefore, our research team built an AI system that can obtain vital data using an ultra-small sensor and determine its early signs. This ultra-small sensor can be easily worn as a wearable device, allowing measurements to be taken while going about one's daily life. Furthermore, in addition to pulse waves, it is possible to simultaneously measure multiple vital data such as electrocardiograms, and this type of integrated data analysis has made it possible to achieve more accurate analysis.

(※1) A stroke caused by a blood clot formed in the heart blocking a blood vessel in the brain; it is a highly serious illness.

Image of integrated data analysis

What research are you currently focusing on?

Umezu: I am focusing on developing sensors that analyze sweat. Until now, sweat has never been used as a source of vital data. This is because sweat tends to stay on the skin and then run off, making it difficult to analyze in real time. I cannot provide details as this research has not yet been presented at an academic conference, but I hope that by using new measurement technology to analyze minute amounts of sweat, we will be able to obtain comprehensive data and find connections with various diseases.

Micromachine technology that protects people's health and lives

Please tell us about the joint research between Professor Umezu and Professor Sato.

Umezu: Professor Sato and I are both researchers ofMEMS (micromachines) (*2), which are also used in the healthcare field. We both graduated from School of Science and Engineering at Waseda University and met during our doctoral studies. It all started when Professor Sato became interested in the basic research on MEMS that I was focusing on at the time. At the time, Professor Sato was researching electroless plating, which is also often used in MEMS. This common point led to our joint development of combining stereolithography 3D printer equipment with plating.

(※2) An abbreviation for Micro Electro Mechanical Systems, which means tiny electromechanical systems.

A complex 3D metal and resin structure created using a stereolithography 3D printer jointly developed by Professor Umezu and Professor Sato.

Sato: Generally, 3D printers handle either plastic or metal, so it is difficult to form metal circuits or antennas in structures made of plastic, limiting their electronic functions. The 3D printer that uses electroless plating, which we developed in collaboration with Professor Umezu, makes it possible to create composite parts of plastic and metal, overcoming this limitation.

Professor Hirotaka Sato (Nanyang Technological University)

What are some of the current topics of technological development in the healthcare field that you are interested in?

Umezu: As with sweat, I am also focusing on brain waves. Although brain waves are the subject of many researchers' research, it is still an area where there is a great deal that is unclear. We are at the stage where we are questioning whether we can even correctly distinguish the brain waves associated with emotions such as joy, anger, sadness, and happiness.  If I am successful in improving our measurement technology in the future, we may be able to understand the current state of the brain and clarify, for example, when and how to intervene in order to maintain concentration.

Sato: The technology developed for cyborg insects can also be applied to human health. The core technology of cyborg insects is a small electronic device that can emit electrical signals. This can be applied to support patients who have lost limbs due to spinal cord injuries or other reasons. Even if a patient's limbs become paralyzed, nerve signals are still sent from the brain. By reading these signals with a brain-machine interface (BMI) (*3) and stimulating the muscles in the limbs with a small electronic device, it will be possible to move the paralyzed limbs.

However, as I am not a medical expert, it is not realistic for me to apply this technology to the medical field on my own. From an ethical point of view, it is essential to further accelerate medical-engineering collaboration involving medical experts. If medical-engineering collaboration can be achieved in this field as well, it will be possible to improve the quality of life (QOL) of those who have suffered accidents.

(※3) Technology and devices that connect the brain to machines. They can read brain waves and neural signals to operate computers.

Expanding the possibilities of research and development through the combination of specialties and encounters with researchers

Please tell us about the vision you two want to achieve through research and development.

Umezu: In a word, the theme is "extending healthy lifespan." It's not enough to just live a long life; I want to aim for a society where the elderly can maintain their health and live vibrant lives.

Professor Sato's cyborg insects will also play an essential role in extending healthy lifespans in emergency situations such as disasters. I intend to continue to take a broad perspective and promote device development and the use of AI in the medical and health fields.

Sato: I will put cyborg insects to practical use at disaster sites as soon as possible. In order to save people's lives, it is too late to think about countermeasures after a disaster occurs. Also, research and development cannot be carried out by one person alone. Many supporters, public institutions, private companies, and foundations have helped us with our research, so we will work to put them to practical use as soon as possible in order to repay their support.

Lastly, please give a message to Waseda University students.

Umezu: Waseda University offers the chance to meet many different researchers. I myself met Professor Sato while I was a student. Please pay attention to the researchers around you and think, "I'll ask this person about this field," or "I might make a new discovery through collaborative research with this person." It is also important to further hone your own research and build up a track record that will allow you to become a co-researcher. I hope you will take advantage of the unique environment at Waseda to expand the possibilities of research and development.

Sato: I have been working on research across multiple fields, including electrochemistry, electronics engineering, and mechanical engineering. I cannot compete with my mentors and seniors in each of these fields. However, it was because I learned these that I was able to create the cyborg insect. It is also interesting to learn and experience a variety of things, combine them to create a new field for yourself, and take on new challenges, rather than being limited to one specialized field​. Waseda University, with its diverse faculties, departments, and people, is a wonderful place where you can do this.

At Kikui-cho Campus where Professor Umezu's laboratory is located