Developmental Study of A New Non-invasive Monitoring System Using System Identification for The Dental Care of Aged Patients (2)

2005 Fiscal Year Final Research Report Summary

• Project/Area Number: 16591985
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Surgical dentistry
• Research Institution: Tokyo Medical and Dental University
• Principal Investigator: OHWATARI Tsuneto Tokyo Medical and Dental University, Faculty of Dentistry, Associate professor, 大学院医歯学総合研究科, 助教授 (80194322)
• Project Period (FY): 2004 – 2005
• Keywords: Elderly / Dental care / Hypertension / System identification

Research Abstract

For the prediction of unexpected hypertensive crises using system identification of circulatory system, the incidence of hypertensive crises and its relationship between patients backgrounds were investigated retrospectively in elderly dental outpatients. The subjects of this study was 3679 dental outpatients aged over 70 years old, who visited our dental office for the purpose of invasive dental care under monitoring. The incidence of hypertensive crises was 6.0%. of 5664 dental procedures of 3679 elderly outpatients. A history of hypertension and grade 2 or 3 blood pressure (WHO/ISH 1999) at first dental visit were significantly associated with hypertensive crises.
In the second study, the decrease of cardiovascular regulation of the elderly was investigated. by using mathematical system identification. The subjects were four elderly aged over 70 years old and four young healthy patients. System identification was performed to estimate a mathematical model between the ventricular contractions and the arterial blood pressure fluctuation. Electrocardiogram and non-invasive arterial blood pressure were used as input signal and output signal of the block box, respectively. In parameters of process model, there was not significant difference between elderly group and younger group. Although we could not revealed a significant decrease of the caardiovascular regulation in the elderly, we think that the system identification of cardiovascular regulation maybe a useful procedure as an evaluation method of the instability of blood pressure.