| Project/Area Number |
59480290
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Thoracic surgery
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| Research Institution | Institute for Medical and Dental Engineering |
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Principal Investigator |
TATSUO Togawa Tokyo Medical and Dental University, 医用器材研究所, 教授 (40013859)
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| Co-Investigator(Kenkyū-buntansha) |
SUMA Kozo Tokyo Women's Medical College, 第二病院, 教授 (00075186)
TAMURA Toshiyo Same as above, 医用器材研究所, 助手 (10142259)
TOYOSHIMA Takeshi Same as above, 医用器材研究所, 助手 (40014146)
TSUJI Takayuki Tokyo Medical and Dental University, 医用器材研究所, 助教授 (00075764)
NEMOTO Tetsu Same as above
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| Project Period (FY) |
1984 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥5,300,000 (Direct Cost: ¥5,300,000)
Fiscal Year 1986: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1985: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1984: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | cardiac pacemaker / heart rate / physical activity / posture / exercise / 時定数 |
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| Research Abstract |
The aim of this project was to obtain necessary informations for the development of a cardiac pacemaker which is controlled by signals came from sensors in the body. We analyzed the response of heart rate to physical activity rate detected by an accelerometer, and to posture detected by an slope sensor. Then, the algorithm which gives appropriate pacing rate was determined, and variations of parameters in the algorithm between subjects were investigated. To do this, 24 hours continuous observations of heart rate, physical activity and posture were made in unconstrained volunteer subjects, and the response of heart rate to physical activity and posture was analyzed numerically. As the results, the heart rate during standing was above about that 12% during sitting, and that during lying was below about 12% that during sitting. We recognized that the response to posture was only static. However, it was shown that the response of heart rate to physical activity had dynamic component and was simulated by a first order system having a time constant of about 70 minutes. This fact had not ever been recognized, and thus it is an important result of this study. Applying this model to the records in 5 subjects, the heart rate predicted from physical activity and posture was close to the actual one with correlation coefficient 0.844 <-!+> 0.042 for 24 hours. A significant variation in the model parameters between subjects was observed only in static response which was considered as to relate to the level of training to exercise, and other parameters were remained within <+!-> 20%.
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