Yoichi Haga | PubMed Health

PubMed2006

Minimally invasive diagnostics and treatment using micro/nano machining.

Several medical tools with various functions have been developed for minimally invasive diagnostics and treatment. Microfabrication techniques such as MEMS technology are useful for the realization of high-performance multifunctional minimally invasive medical tools with small sizes. An ultra-miniature pressure sensor and an intravascular ultrasonic forward-viewing imager have been developed as microsensors for use in the human body. Active bending catheters have been developed for steering catheter tips without using traction of wires from outside the body. An ultrasonic therapeutic tool for sonodynamic therapy and sonoporation, and a micro scanner for precise laser treatment have been developed as therapeutic tools for use in the human body. High-functionalized endoscopic tools and catheters will enable more precise and safe diagnostics and therapy, as well as novel diagnostics and treatment which have been impossible to date.

Alloys↗

PubMed2003

Artificial myocardium with an artificial baroreflex system using nano technology.

Where is the place which should be helped in a patient with congestive heart failure? The answer may be contraction of the heart. At Tohoku University, development research of "the artificial myocardium" has been conducted, using a ball screw type electromagnetic motor. Furthermore, super-miniaturization is being attempted at present. Thus, a system with shape memory alloy is being developed. The cooling speed problem was solved by the application of the Peltier element. A drive at a speed equal to that of a heartbeat was realized by the application of this system. At present, a ventricular assist device is used for patients waiting for a heart transplant in Japan. An air driven type system disturbs a patient's QOL remarkably because it is connected to the drive device. With our concept, energy is provided by using the electromagnetic force from outside of the body by the use of transcutaneous energy transmission system. Magnetic shielding by amorphous fibers was used at Tohoku University to improve the total efficiency. A natural heart can alter the cardiac output corresponding to the demand. Artificial internal organs must participate in the system of the living body, too. Tohoku University has developed a resistance based artificial heart control algorithm, which simulated a baroreflex system to cope with every demand. Nano level sensing equipment is now under development at Tohoku University. At present, development is being conducted aiming at an "intelligent artificial myocardium".

Baroreflex↗