• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Application of chaotic vibrations to the development of a bedsore-prevention bed

Research Project

Project/Area Number 15560194
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Dynamics/Control
Research InstitutionGunma University

Principal Investigator

NAGAI Ken-ichi  GUNMA UNIVERSITY, Faculty of Engineering, Professor, 工学部, 教授 (00110403)

Co-Investigator(Kenkyū-buntansha) YAMAGUCHI Takao  GUNMA UNIVERSITY, Faculty of Engineering, Associate Professor, 工学部, 助教授 (90323328)
MARUYAMA Shinichi  GUNMA UNIVERSITY, Faculty of Engineering, Research Associate, 工学部, 助手 (60344925)
Project Period (FY) 2003 – 2005
Project Status Completed (Fiscal Year 2005)
Budget Amount *help
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2005: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2004: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2003: ¥1,500,000 (Direct Cost: ¥1,500,000)
KeywordsChaos / Biomedical Measurements / Nonlinear Time-Series Analysis / Nursing / Sound and Vibration / Flexible Structures
Research Abstract

Recently, the number of bedridden old people is increasing. One of the most serious problems of these people is a bedsore, also called pressure ulcers, which is caused by inadequate blood supply due to prolonged pressure by bony areas resulting in necrosis of tissues. To prevent the bedsores, it is necessary to relax the pressure on one's body, which requires large manpower for nursing. Application of mechanical vibrations, especially chaotic vibrations with broadband spectra, is a potential way to prevent the bedsores. In this research, biological signals of a human body subjected to time-varying pressure are measured and analyzed as a fundamental study aiming at developing a bedsore-prevention bed. Sinusoidal pressure and chaotic pressure are applied to the loins, in reclined position on the bed. Electrical signals on the skin are then measured : an electrocardiogram (ECG) is detected from the chest of the body, while an electromyogram (EMG) is detected from the muscles of both arms. Pulse sound diagram (PSD) is recorded with a microphone. Based on time-series of ECG, EMG and PSD, the signals were then analyzed by power spectra and by calculation of their Maximum Lyapunov exponents. It is found that waveforms of EMG of a human body are sensitive to sinusoidal pressure, while waveforms of ECG are not. The maximum Lyapunov exponents of EMG after the excitation whether by sinusoidal or chaotic pressure take larger values than those before the excitation, which suggests that signals from the muscles are activated by the time-varying pressures. In contrast, chaotic pressure gives the ECG lower Maximum Lyapunov exponent in both normal and blood-stagnated condition. Same trend is found for the PSD under blood-stagnated condition. These results suggest that time series of heartbeat tends to become periodically by the chaotic pressure.

Report

(4 results)
  • 2005 Annual Research Report   Final Research Report Summary
  • 2004 Annual Research Report
  • 2003 Annual Research Report
  • Research Products

    (6 results)

All 2006 2004

All Journal Article (6 results)

  • [Journal Article] カオス状変動圧迫力を与えた生体時系列信号の分析2006

    • Author(s)
      永井健一
    • Journal Title

      日本機械学会関東支部第12期総会講演会講演論文集 No.060-1

      Pages: 455-456

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Biological signal analysis of human body subjected to chaotic excitation.2006

    • Author(s)
      Ken-ichi Nagai, et al.
    • Journal Title

      Proceedings of the 12^<th> Kanto Branch Regular Meeting of the Japan Society of Mechanical Engineers No.060-1

      Pages: 455-456

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] カオス状変動圧追力を与えた生体時系列信号の分析2006

    • Author(s)
      永井健一
    • Journal Title

      日本機械学会関東支部第12期総会講演会講演論文集 No.060-1

      Pages: 455-456

    • Related Report
      2005 Annual Research Report
  • [Journal Article] 局部変動圧力を与えた生体時系列信号の分析2004

    • Author(s)
      永井健一
    • Journal Title

      日本機械学会機械力学・計測制御部門講演会アブストラクト集,CD-ROM論文集 No.04-5

      Pages: 162-162

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Biological signal analysis of human body subjected to local dynamic pressure.2004

    • Author(s)
      Ken-ichi Nagai, et al.
    • Journal Title

      Proceedings of the Dynamics and Design Conference, Japan Society of Mechanical Engineers No.04-5

      Pages: 162-162

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] 局部変動圧力を与えた生体時系列信号の分析2004

    • Author(s)
      永井健一, 丸山真一, Syamsul S.Hashim, 山口誉夫
    • Journal Title

      日本機械学会機械力学・計測制御部門講演会アブストラクト集,CD-ROM論文集 No.04-5

      Pages: 162-162

    • Related Report
      2004 Annual Research Report

URL: 

Published: 2003-04-01   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi