1998 Fiscal Year Final Research Report Summary
STUDY ON REAL-TIME MEASUREMENT OF CARDIAC MUSCLE VISCOELASTICITY USING AN ULTRASONIC TACTILE MICROSENSOR CATHETER
| Project/Area Number |
08458296
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | NATIONAL CARDIOVASCULAR CENTER RESEARCH INSTITUTE |
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Principal Investigator |
TSUJI Takayuki NATIONAL CARDIOVASCULAR CENTER RESEARCH INSTITUTE,DEPARTMENT, DIRECTOR, 実験治療開発部, 部長 (00075764)
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| Co-Investigator(Kenkyū-buntansha) |
OMATA Sadao NIHON UNIVERSITY FACULTY OF ENGINEERING, PROFESSOR, 工学部, 教授 (90060186)
FUJISATO Toshia NATIONAL CARDIOVASCULAR CENTER RESEARCH INSTITUTE, RESEARCHER, 実験治療開発部, 室員 (60270732)
MIYAWAKI Fujio NATIONAL CARDIOVASCULAR CENTER RESEARCH INSTITUTE, CHIEF RESEARCHER, 実験治療開発部, 室長 (50174222)
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| Project Period (FY) |
1996 – 1998
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| Keywords | ultrasonic tactile sensor / resonant frequency shift / microtip catheter / viscoelasticity / beating heart muscle / in vivo organ viscoelasticity |
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| Research Abstract |
Aim of the project is to develop a tactile sensor catheter having 1.5 mm in diameter equipped with the 200 kHz ultrasonic microtip that can detect in real-time viscoelasticity change of beating heart muscle. Influence of contact pressure of the tip on the objects which are silicone rubber discs having various silicone contents from 40 to"90 % was studied by varying tip weight loaded with various sizes of lead chips from 5 to 100 g. Ultrasonic resonant frequency shift (DELTAf) depended on the tip load. Five gram load was decided appropriate for measuring soft tissues.
The negative DELTAf became bigger in softer material. Viscoelasticity measurements of in vivo organs including liver, kidney, spleen and muscles in anesthetized dogs revealed the DELTAf of muscle was smaller than other tissues. Skeletal muscle, kidney, liver and spleen were softer in order. Dynamic changes associated with the left ventricular wall motion was obtained by the catheter inserted via carotid artery However, the signals originating from viscoelasticity changes of the ventricular muscle and from the tip collision against the ventricular wall in systole cannot be discriminated. Improvement of the catheter should be necessary for this purpose.
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