Biomedical Engineering Course Assoc. prof. Tokitada HASHIMOTO E-mail:hasimoto [at] cc.saga-u.ac.jp (Please replace [at] with @ in e-mail address.) Academic Staff Database Laboratory Home Page (Japanese)

Education: 1998 Tohoku Univ., Faculty of Engineering, Graduated 2000 Tohoku Univ., Graduate School, Division of Engineering, Master Course, Completed 2003 Tohoku Univ., Graduate School, Division of Engineering, Doctor Course, Completed Employment Experience: 2008-2010 Saga Univ., Faculty of Science and Engineering, Mechanical Engineering , Lecturer 2010-2012 Saga Univ., Graduate School of Science and Engineering Advanced Technology Fusion, Lecturer 2012- Saga Univ., Graduate School of Science and Engineering, Department of Advanced Technology Fusion Advanced Technology Fusion, Associate Professor

Research Field :  Fluidics

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The novel therapy using focusing underwater expansion wave

A shock wave therapy is a method that utilizes a property of pressure wave to transmit the boundary between materials with the same order of acoustic impedance as water and a biotissue. Since dynamic destruction and stimulation can be provided depending on the strength of the shock wave, the shock wave has been applied to the various medical fields as a minimally invasive and a non-medicinal therapeutic approach. In the shock wave therapy, it has been well known that an expansion wave appears inside the body. The expansion wave is a kind of the pressure waves like the shock wave, but the property is contrastive. However, there are few studies on the expansion wave. Hence it is necessary to get adequate knowledge about the effect on a human living tissue during the expansion wave irradiation.

Therefore, If the expansion wave can be controlled and directly operated on the living body, we think that underwater expansion wave has a possibility of novel medical therapy. Particularly, since it is expected that the number of patients about the field of cardiovascular medicine will greatly increase in future, the establishment of the method that some disease can be treated without depending upon a drug and performing surgical operations is very significant for the society.

Medical application of water jet

In this study, researches on application to medical care using liquid (or water) jet are carried out.

The first applied example includes a medical pulsed water jet scalpel. A surgical treatment became able to apply to a difficult case by technical improvement of the medical equipment. However, the success or failure depends on skill of the medical staffs still in the actual surgical operation. For example, it is a key in the neurosurgical procedure that thin blood vessels remain as much as possible. Therefore the introduction of the water jet scalpel has attracted attention. It is thought that blood vessel can be kept by using the elastic difference between biotissue and blood vessel.

As the second applied example, delivery system in the body of a gelatinous drug using a high-speed liquid jet has been studied. The size to be settled with one hand is assumed as final completion form. This method is an innovative method to transport gel particles with less than 20μm to the body.

Fundamental Study on High-Speed Particle Induced by a Micro Shock Tube

Recently injection system without a needle and pain, which is called needle free injection (NFI), has been investigated all over the world. The method may be useful for not only patients that must use injectors very frequently but also medical staffs. We are interested in a powder injection method that makes use of a shock tube technology. A powder particle with the order of 10 ƒÊm or less is often used. The powder injection is one of the NFI systems, and is the method that transdermally administers powder particles accelerated over the sound speed using the shock tube technology inside human body.