Catheter-based diagnosis and therapy have become increasingly popular. Conventional catheters cannot move actively and the operations require certain human skill. The tip of active catheters and active guide wires moves actively using shape memory alloy actuators. Several micro sensors and therapeutic devices have been also developed for minimally invasive diagnosis and therapy. These devices can be used in other areas in human body and enables novel diagnosis and therapy.
3 Shape Memory Alloy coils are extended and fixed in the stainless steel
coil. It bends in several directions using shape memory effect by applying
current from outside.
This catheter will be useful for choosing blood vessel branches and precise
positioning in the human body.
Outer Diameter and length of the fabricated bending mechanism is 1.6 mm
and 19 mm respectively. It bends about 45 degree by applying current of
90 mA.
Video (MPEG) will be played by click (File size: 500KB)
ReferenceFSmall Diameter Active Catheter Using Shape Memory Alloy Coils
Trans. IEE of Japan, Vol.120-E No.11 (2000), p509-514
Y.Haga and M.Esashi
(In Japanese)
Active Ileus Tube Using SMA Coil Actuator
Soft and long silicone rubber tubes (catheters) are commonly used for conservative treatment in intestinal obstruction (ileus). It is difficult to pass the passage at the lower end of the stomach (pylorus). Doctors must be skillful and experienced enough to insert the tube into the intestine. Although there are some instruments which make the procedure easier, for example an endoscope, a guide wire, a long over tube and attaching weight at the tip of the tube, easier and more certain method has been required to pass the pylorus. Active bending tube using shape memory alloy coil micro actuator has been developed. Doctors can control bending motion of the tip of the ileus tube easily by applying electrical current to the SMA actuator from outside the body.
Insertion of Ileus Tube ___________________________________________________________
Pylorus and Ileus Tube
Video (MPEG) will be played by click (File size: 600-700 KB)
Video (MPEG) will be played by click (File size: 500KB)
A torsionally deformed Shape Memory Alloy coil is fixed in the stainless
steel coil and it moves torsionally using shape memory alloy effect by
applying current.
This catheter will be useful for rotationg the tip of the catheter at the
blood vessel branches.
Outer Diameter and length of the fabricated torsional mechanism is 1.3
mm and 7 mm respectively. It rotates about 70 degree by applying current
of 80 mA.
Video (MPEG) will be played by click (File size: 500KB)
ReferenceFAssembly of Bending, Torsional and Extending Active Catheter Using Electroplating
Trans. IEE of Japan, Vol.120-E, No.11, 2000,
p515-520
Y.Haga and M.Esashi
(In Japanese)
Bending motion of the tip of the cateter is controlled by suction of fluid
(saline) in the catheter.
This catheter will be useful for treatment of tumors by embolization of
embolus (gelatin sponge) (TAE).
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Video (MPEG) will be played by click (File size: 500KB)
ReferenceFDevelopment of Hydraulic Suction Type Active Catheter Using Super Elastic Alloy Tube
PROCEEDINGS OF THE 20TH
SENSOR SYMPOSIUM on Sensors, Micromachines, and Applied Systems, (2003),
57`60
Y.Muyari, Y.Haga, T.Mineta, M.Esashi