Optical Biomedical Engineering at Keio Faculty of Science and Technology: The Potential of Light to Illuminate the Future of Medicine

Every process of research is enjoyable

Ms. Ogawa had decided to enter her current field of research since her first year of university. How was her attitude of pursuing what she wants to do and boldly taking on challenges nurtured? She continues to move forward, turning even harsh experiences into nourishment for life while expanding her connections with people.

Featured this time is Associate Professor Emiyu Ogawa, who aims to save as many patients as possible by developing new medical technologies using light.

For those of us living under the sun, light is very familiar. On the other hand, because light has various effects on the mind and body, it holds the potential for application in unprecedented therapeutic and diagnostic technologies. Ms. Ogawa of the Department of Electronics and Electrical Engineering, who was attracted to the potential of light during her student days, is developing new medical devices using light. We asked her about how light will be useful for future medical care, the appeal of light, and the forefront of her research.

In the summer of her first year at university, Ms. Ogawa was strongly attracted to the potential of light when she visited the laboratory of Professor Tsunenori Arai (now Professor Emeritus) of the Department of Applied Physics and Physico-Informatics, who was researching therapeutic technologies using light. "Light has various effects on living organisms depending on its wavelength. For example, short-wavelength blue light wakes you up, and long-wavelength far-infrared light reaches deep into the body and has a warming effect. It is truly mysterious that it has such effects even though it does not touch you directly. The Arai Laboratory is developing technologies for minimally invasive treatment and diagnosis by utilizing the characteristics of light, and I was impressed, thinking it was 'like magic,'" she recalls.   Ms. Ogawa originally aspired to a career in medical sciences and was considering re-entering a School of Medicine as a student enrolled in one university while preparing for entrance exams to another, but she was struck by Professor Arai's words: "New technology has the potential to save the lives of future patients even after you have left this world." She decided on her current path, thinking, "This is what I want to do!" Since then, at the Arai Laboratory and later at Kitasato University, she has worked on medical-engineering collaboration research that integrates medical sciences and engineering in cooperation with doctors. Every time she hears about troubles or issues in clinical practice from doctors, she thinks, "Could light be used here too?" and has expanded her research by finding areas where light can be utilized. Currently, she is proposing and realizing new treatment methods and diagnostic technologies using light technology in various medical fields such as cancer, cardiovascular diseases, and mental disorders.   

One of the noteworthy recent research results is a new approach to treating Parkinson's disease using special light.

  Parkinson's disease is an intractable disease for which a fundamental cure has not yet been established. It is common among the elderly, occurring in about 1 in 100 people aged 65 and over, with symptoms such as hand and foot tremors and difficulty moving the body. The cause of the disease is a decrease in the amount of dopamine, a neurotransmitter. Proteins that cause the disease aggregate and accumulate in a part of the brain called the substantia nigra, which causes nerve cells in the substantia nigra to die and dopamine production to decrease. Ms. Ogawa wondered if a special light called an "optical vortex" could be applied to the treatment of Parkinson's disease. An optical vortex is light with a spiral wavefront and has the property of exerting a rotating force on the object it irradiates. She came up with the idea that this force could be used to break up the aggregates that cause the disease, and that by further activating cells with light stimulation, they could be returned to a state where they can produce dopamine again (Figure 1).

 This idea was born from a casual conversation at an academic conference. "When I was talking with Professor Katsuhiko Miyamoto of Chiba University, who is researching optical vortices, I thought that optical vortices could act on proteins and organelles contained in living organisms and be used for new treatments. When I mentioned that idea to Professor Fumitaka Kawakami of Kitasato University, who is researching Parkinson's disease, he encouraged me, saying, 'I feel there is potential in that. Let's try it,' and joint research began."

In fact, when they created model cells in which the protein causing Parkinson's disease was aggregated and irradiated them with an optical vortex, the causative protein decreased by about 20%. Even more surprisingly, the production of dopamine precursors increased to 150%. "In the field of life sciences, even a 10% change is evaluated as a meaningful effect. Based on that, 150% is a remarkable result. Professor Kawakami was also surprised, saying, 'This is amazing,'" says Ms. Ogawa.

Research using optical vortices on biological tissues was unprecedented, and combining the physical action of breaking up aggregates with the biological action of activating chemical reactions occurring within cells with light was the world's first attempt. This eye-opening result shows the potential to open up a new field of research. Regarding the innovativeness of using light, Ms. Ogawa explains, "By using light with a frequency and wavelength matched to the size of the target organelle, light can be irradiated pinpoint to only that organelle. This allows for an approach that is completely different from conventional chemical treatment with drugs."

There is research that is already nearing practical application. When massive bleeding occurs due to trauma or other causes, emergency hemostasis is necessary. A method that has become widespread in recent years as a treatment is to inflate a balloon inside a blood vessel to block blood flow from within the vessel and stop the bleeding. However, if the balloon is inflated too much, there is a risk of the blood vessel rupturing or damage caused by excessive blood flow blockage, and conversely, if the balloon is not inflated enough, sufficient hemostasis cannot be achieved. Currently, the inflation of the balloon is adjusted based on the doctor's intuition, and no objective criteria exist. Ms. Ogawa thought that light could be used for this challenge. "We pass an optical fiber through the balloon and irradiate light (Figure 2). If there is blood between the balloon and the vessel wall, the light is absorbed by the blood and does not return. On the other hand, if the balloon is in close contact with the vessel wall and there is no blood, the light is not absorbed but reflected back. By detecting the returning light, the thickness of the blood layer between the balloon and the vessel wall can be determined, and this serves as a basis for appropriately adjusting the balloon's inflation." In addition, the blood flow rate (m3/sec) can also be calculated, and by performing the procedure while monitoring the blood flow rate, the risks mentioned above can be suppressed. This hemostatic balloon system using light is aimed for use in emergency medical settings in collaboration with doctors from Kitasato University and manufacturers, and is scheduled to be commercialized soon.

Ms. Ogawa's interest in light is also connected to the paintings of Claude Monet, which she has liked since she was a child. Monet pursued the "transience of light" and painted water lilies and garden landscapes. "It is said that Monet continued his creative activities throughout his life, wanting to paint pictures that would heal the hearts of wounded people. We, living exactly 100 years later, are indeed healed and given hope by Monet's paintings. I also overlap my thoughts with Monet, hoping to create medical devices using light technology that can heal people and save lives even 100 years from now."

While pushing forward with research with such thoughts in mind, she is also focusing on the guidance and development of students. "Winning research competitions is important, but I believe that nurturing students with the aspiration to 'make the world a better place' or 'create something useful for medical care' is also of very important value as an educator. Cooperating with each other in teamwork and creating better things together. I consider everyone in the world involved in medical care to be one big team challenging themselves to save lives, and I want to nurture students who can learn and grow together as members of that team."

(Interview and composition by Chisato Hata)

An Interview with Associate Professor Emiyu Ogawa

I grew up in a family where both parents were musicians; my father was a cellist and my mother was a piano instructor. I have been playing the cello since I was three years old and still continue it as a hobby. People sometimes ask, "Do you play classical music during breakfast?" but it's actually the opposite. Since music is work for my parents, we didn't listen to it much at home. My whole family loves baseball, so we often had baseball broadcasts playing on the TV.

I don't remember it very well, but when I looked at my elementary school graduation yearbook, I had written that in ten years, I would be "conducting research in medical sciences at a university." I think I had a pure interest in biology and the human body from that time. Seeing my parents make a living doing what they loved left a strong impression on me from a young age, so I feel like I naturally developed an attitude of pursuing what I enjoy.

I liked chemistry and biology, but I wasn't very good at physics. In my first year of university, I decided I wanted to join Professor Tsunenori Arai's laboratory, so I chose the Department of Applied Physics and Physico-Informatics for my second-year department assignment. People around me were worried, asking, "Are you sure you'll be okay since you're not good at physics?" But I had a strong feeling of "This is what I want to do!" so I had no hesitation. I have maintained that attitude of doing what I want to do to this day.

My sister is in the Department of System Design Engineering, where she researches architectural systems that support healthy and safe living. Although our fields are quite different, we often talk about wanting to create a "Health House" in the future that incorporates optical technology into daily necessities and furniture.

When I went on a trip to Paris with my father during the winter break of my second year, I was so moved by the beauty of the Palace of Versailles that I decided to make "living in France my life goal." Just then, I found a poster on the Keio University campus recruiting for a double degree program with France. I applied with the feeling of, "My dream of living in France is already coming true! Let's give it a try!"

For two years during my third and fourth years of undergraduate study, I studied abroad at a Grande École (a higher education institution providing specialized education) in Lyon, France. There, I took all the same classes as the local students, entirely in French. We had four two-hour classes from 8:00 to 18:00 with a long lunch break, and we studied a wide range of subjects from science and engineering like mathematics, control engineering, and condensed matter physics to psychology and business administration. Because I had to do a massive amount of studying, I learned how to study efficiently.

At first, I had no idea what was being said in class. After about three months, I started dreaming in French, and I gradually began to understand the lessons. Since I was the only Japanese person, the environment where I had no choice but to speak French was good for me. Through my study abroad experience, I was able to grow mentally and take on any challenge.

Also, since international students from all over the world go through the same harsh experiences, a strong sense of camaraderie develops. Because of the language barrier, we express our emotions directly, which led to friendships where we could talk about anything, and I even made an irreplaceable best friend.

Study abroad can be difficult, but the experience of struggling and working hard becomes a pillar that supports you. You gain experiences that become lifelong assets and make friends for life, so I hope students will definitely take the challenge if they have the opportunity to study abroad.

Anyway, every day was fun. I am very particular about experimental protocols, so I plan everything to proceed efficiently without mistakes or waste, and I create an experimental schedule from morning to night in Excel. First of all, thinking deeply about that plan is fun in itself, and it's also fun when things go according to plan. My favorite moment is when I can draw a graph from the experimental data. So, when the experiment was over, I couldn't wait; if I could get a seat on the train home, I'd think, "Yes! I can organize the data," and open my laptop on my lap to analyze the data in the Excel file. The moment the graph appears after setting the vertical and horizontal axes is the most exciting part for me. I would create PowerPoint presentations with a grin, wanting to show them to Professor Arai as soon as possible.

Yes. In the past, I wasn't very good at cooking, and my family used to tell me, "You're not good at cooking, are you?" That frustrated me, so I thought, "If I can make a full-course French meal by myself, they won't say I'm bad at it anymore," and I took on the challenge. To make a full course for the whole family and still be able to eat it myself, I created a schedule in Excel—preparing this dish here, heating this while eating that—and executed it. As a result, it was a success. Since then, it has become a tradition for me to cook and serve a full-course French meal to my family every Christmas.

It might be a bit unusual, but anyway, it's "health first." If you lose your health, you can't conduct good research or have an enjoyable student life, so I strongly hope that students spend their time in good physical and mental health. Since it's often difficult to notice concerns in daily life, I set up opportunities for individual interviews about once every six months, separate from research meetings. I want to support each student while facing them individually, asking how they feel about their current life and how they want to grow in the future.

Also, graduate school and the fourth year of undergraduate research are the final educational settings before entering society, so I believe I play an important role as an instructor. I want students not only to engage in research but also to find their aptitudes and strengths and become people who can play an active role in the world. Through research activities, I hope they acquire skills useful in society, such as writing ability, presentation skills, and schedule management skills.

What I feel particularly strongly after graduating is the strength of the connection known as "Keio colleagues." Of course, other universities have alumni connections, but I feel that Keio University has an especially strong bond. Human relationships are at the root of any job and will not be lost even as various technologies and AI evolve. In that sense, I think this network is a great strength.

The alumni organization, "Mita-kai," exists not only throughout Japan but also all over the world, and it is a reassuring presence. When a friend was studying abroad in Paris and was having trouble finding an internship host, they consulted the Paris Mita-kai and were able to get an introduction.

There are also regular alumni meetings and social gatherings through the connections of the "Fujiwara Scholarship" and the "Fujiwara Award," which encourage double degree programs and international activities. I have also received the Fujiwara Award and a scholarship from the Fujiwara Scholarship, and I participate in cross-generational exchanges at social gatherings. Such interactions are a great encouragement and make me feel positive, thinking, "I'll do my best too."

(Interview/Composition: Chisato Hata)