of Medical and Dental Bioengineeringに留学し研究に従事
1990年 同 講師に昇進
1993年 国立循環器病センター研究所・実験治療開発部 実験外科室長に就任
1999年 東京電機大学 教授（理工学部、大学院修士課程、大学院博士課程）となり、現在
1988年 第26 回日本人工臓器学会Young Investigator’s Award
1991年 第17 回日本心臓財団研究奨励賞
“From Cells to Robots”
My research interests range from ‘cells’ to ‘robots’. The current main projects are as follows:
1) Development of Scrub Nurse Robot (SNR) System
2) Development of Vibratory Microinjection (VMI) System
3) Development of Recovery-Directed Left Ventricular Assist Device (RDLVAD)
4) Research on antithrombogenicity of magnetite
Because the details and actual states of the above 4 projects are shown on the respective pages in this homepage, I mainly explain the background and aim of each project.
1) Development of Scrub Nurse Robot (SNR) System —— some patents are applied
for We have been developing the SNR system to compensate for chronic and severe shortage of scrub nurses who pass sterile equipment (surgical instruments, absorbent gauze and others) to surgeons to help them perform a surgical operation. We never intend to take away jobs from human scrub nurses. The goal of this project is to develop a robot that is capable of behaving like an ‘ideal’ scrub nurse who (if one exists) is able to accurately anticipate which surgical instrument a surgeon will need next (without any verbal order) and to pass it to a surgeon without making him/her wait for it, for example, at the moment that the surgeon’s hand is extended to receive it. The idea of the scrub nurse robot and the concept of its behavior are original to us. We have been taking various unique approaches to solve the difficult problems although we really understand that the above-mentioned goal is extremely difficult to attain.
2) Development of Vibratory Microinjection (VMI) System —— a patent is applied
for It is indispensable to produce transgenic animals in the fields of medicine and life sciences. Especially, production of transgenic mice has been widely and actively performed. Several methods can be used to deliver foreign DNA (gene) to cells, but the most efficient one is to inject the DNA directly into a nucleus by a technique called ‘microinjection’. It uses a glass needle called micropipette, the tip of which has an orifice of 1 – 2 m. The sharp tip containing a small amount of gene solution is inserted into a cell nucleus (a pronucleus in the case of a fertilized egg) to inject a minute amount of the solution. In order to raise the production rate of transgenic animals by increasing the efficiency of the microinjection, we invented a vibratory microinjection (VMI) system. The VMI system vibrates the micropipette longitudinally, thereby facilitating penetration of the cell nucleus. Compared with the conventional (non-vibratory) microinjection, the VMI for pronuclear injection is capable of significantly shortening the time spent injecting DNA. Because this shorter injection time is mainly caused by much higher speed of injecting DNA into pronucleus, the VMI can deliver larger and/or stickier DNA that cannot be introduced by the ordinary microinjection, therefore widening application of microinjection.
3) Development of Recovery-Directed Left Ventricular Assist Device —— patented in Japan, USA and Europe Ventricular assist devices (VADs) have long been clinically used for treatment of patients with severe heart failure and their use has become an established therapeutic measures. Pulsatile-flow-type VADs, however, are not fit for relatively small-sized patients like Asians but for larger ones. Therefore, continuous-flow-type VADs that can be theoretically miniaturized and lightened are now widely investigated to support smaller patients. Even these two types cannot save all patients with severe heart failure. It is said that patients cannot survive if they are not able to adapt to hemodynamic change brought by a VAD within one or two weeks after implantation of VAD. I imagined that much more patients would be able to survive if what adapted was not a patient with severely damaged adaptability but rather a VAD, and invented the Recovery-Directed Left Ventricular Assist Device (RDLVAD).
RDLVAD has two features. One feature is its fine adjustability of ventricular pressure work. The RDLVAD is capable of finely adjusting left ventricular pressure work to a level favorable for promotion of cardiac recovery. For example, it is able to reduce peak left ventricular pressure to a level less than 10 mmHg (a quarter of that in the case of continuous-flow-type LVAD) during systole in the case of extremely severe heart failure, suggesting excellent left ventricular unloading. It can also precisely set the ventricular pressure work to such a level as to give an appropriate training to a recovering heart. The other feature is not to restrict ventricular relaxation. In other words, the RDLVAD is capable of allowing a proper ventricular dilatation (stretching of cardiac muscle) necessary for the ventricle during diastole whereas the continuous-flow-type VADs, by contrast, restrict the necessary ventricular dilatation (the ventricular relaxation decreases as they increase their flow assistance).
I believe that the above-mentioned two features of RDLVAD are keys to promotion of cardiac recovery. We have been demonstrating in animal and laboratory experiments that the RDLVAD is capable of realizing the two features. We are now conducting a research toward its clinical use.
4) Research on antithrombogenicity of magnetite
Magnetite (Fe3O4), a ferromagnetic material, is applied to various kinds of products ranging from daily necessaries to industrial products. I happened to find that magnetite did not easily coagulate blood put on its surface. Since then, we have been examining how antithrombogenic magnetite is and why it is antithrombogenic. Because we made its antithrombogenic mechanism considerably clear, we are now searching for possible clinical applications.