| Project/Area Number |
20K12046
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 62010:Life, health and medical informatics-related
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| Research Institution | The University of Aizu |
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Principal Investigator |
Maxim・V Ryzhii 会津大学, コンピュータ理工学部, 上級准教授 (50254082)
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| Project Period (FY) |
2020-04-01 – 2025-03-31
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| Project Status |
Granted (Fiscal Year 2023)
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| Budget Amount *help |
¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Fiscal Year 2022: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2021: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
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| Keywords | atrioventricular node / rabbit heart model / Aliev-Panfilov model / dual pathway / AVNRT / Wenckebach periodicity / ECG / MATLAB / cardiac conduction curve / coupling asymmetry / retrograde conduction / ladder diagram / Corrado-Niederer / Aliev-Panfilov / "natural pacemaker" / "nonlinear equation" / "dual pathway" / "cardiac model" / intestine / "sinoatrial node" / Mitchell-Schaeffer / pacemaker / nonlinear equation / oscillator / cardiac model / arrhythmia / computer modeling / conduction system / implantable device |
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| Outline of Research at the Start |
We are going to develop a simple comprehensive computer model of conduction system of the heart for implantable pacemaker testing and cardiac arrhythmia study. Using the developed model, we will perform various computer simulations of the cardiac rhythm disturbances, and investigate possible methods of their control.
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| Outline of Annual Research Achievements |
* Using our AV node model we studied the onset of typical and atypical forms of atrioventricular nodal reentrant tachycardia (AVNRT) and revealed their origin and clinical incidence. We demonstrated for the first time using computer simulations that differences in the effective refractory periods of slow and fast pathways during anterograde and retrograde conduction determine
the type of AVNRT. The obtained results explain significant prevalence of the typical type over atypical one.
* We simulated Wenckebach patterns with our AV node model and revealed the domination of atypical Wenckebach forms with high AV conduction ratios at lower atrial pacing rates. We observed that Wenckebach phenomenon occurs at regular atrial pacing rhythms with cycles shorter than effective refractory periods of fast pathway, more precisely, shorter than the point of transition of conduction from fast to slow pathway. The Wenckebach patterns are formed around the penetrating bundle, where the most pronounced increase of atria-His and His-His interval delays occur.
* We proposed a novel model for generating synthetic ECG, combining AV node with dual pathways, Bachmann’s bandle, and muscle responses. Using the model, we reproduced several cardiac scenarios: tachycardia, AVNRT, atrial fibrillation, and atrial flutter with Wenckebach patterns formation. The model provides a unique possibility to reproduce cardiac conduction scenarios simultaneously as electrical signals inside the cardiac conduction system and outside the body in the form of ECG for better understanding of cardiac electrophysiology.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Using our previously developed model for pacemaking variant of excitable Aliev-Panfilov cardiac cell model, and our compact atrioventricular node (AVN) model for rabbit heart with dual pathway structure, we performed preliminary study of atrioventricular reentrant tachycardia (AVNRT) and formation of Wenckebach periodicity. We also developed a new model for synthetic ECG simulation based on the combination of our compact AVN model for rabbit heart and previously developed cardiac muscle response model. The results were presented at Computing in Cardiology 2023 and IEEE Int. Conference on Bioinformatics and Biomedicine (BIBM 2023). The pertinent inhouse MATLAB software was developed.
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| Strategy for Future Research Activity |
We are in a process of a new improved model development for the rabbit AV node under the influence of autonomic nervous system (ANS). Using the improved AV node model, we are going to consider and simulate the following cardiac phenomena: (a) the onset, sustainability and spontaneous termination of the atrioventricular nodal reentrant tachycardia (AVNRT), (b) influence of ANS on the AV node filtering properties during atrial fibrillation, (c) transformation of Wenckebach patterns under the influence of ANS, (d) further development of our ECG simulation models, including simplest human three-oscillator model and more detailed rabbit AV node model based on modified Aliev-Panfilov equation, to provide wider functionality and detalization with the aim of their future hardware implementation.
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