نوع مقاله : مقاله کامل پژوهشی
نویسندگان
1 استادیار، دپارتمان مهندسی پزشکی، دانشکده برق، دانشگاه علم و صنعت ایران
2 دانشجوی کارشناسی ارشد، دپارتمان مهندسی پزشکی، دانشکده برق، دانشگاه علم و صنعت ایران
چکیده
مطالعة آریتمیهای قلبی به جلوگیری و درمان یکی از مهمترین عوامل مرگ انسانها کمک میکند. برای مطالعه آریتمیهای قلبی نیاز به مدلی از پتانسیل عمل سلولی است که علاوه بر نمایش فعالیت الکتریکی طبیعی سلول، قادر به نمایش رفتارهای غیر طبیعی آن نیز باشد. مدلهایی که تاکنون در این زمینه ارائه شده دارای جزئیات و حجم محاسباتی زیادی هستند و این موضوع سبب کاهش سرعت شبیهسازی آنها شده است. در این مقاله مدل کمینهای با دو متغیر حالت ارائه شده است. این مدل علاوه بر نمایش خصوصیات طبیعی سلول بطنی مانند تحریکپذیری، شکل ظاهری پتانسیل عمل، خاصیت جبران و نمایش اثر محدود کردن جریانهای غشا، میتواند رفتار غیر طبیعی (EAD)را نیز شبیهسازی کند. این مدل ساختاری هدایتی (کندوکتانسی) دارد و شامل دو جریان برایند است که یکی نماینده کل جریانهای ورودی و دیگری نماینده کل جریانهای خروجی از سلول است. تنظیم پارامترهای مدل، با استفاده از الگوریتم تکرار شونده و معیار کمینه مجموع مربعات خطا انجام شده و گسترههای مستعد پارامترها برای بروز رفتار غیرطبیعی EADبا استفاده از روشهای تحلیل سیستمهای دینامیکی غیرخطی تعیین شده است. نتایج به دست آمده منطبق با یافتههای الکتروفیزیولوژیک است. سرعت شبیهسازی مدل مذکور در آرایهای تکبعدی از ده سلول، در مقایسه با مدلهای الکتروفیزیولوژیک، بین 34 تا 112 بار سریعتر تخمین زده شده است.
کلیدواژهها
موضوعات
عنوان مقاله [English]
A minimal two state variables model for action potential in human ventricular cell
نویسندگان [English]
- Seyed Hojat Sabzpoushan 1
- Zahra Daneshparvar 2
1 Assistant professor, Department of biomedical engineering, Iran university of Science and Technology (IUST)
2 M.Sc., student, Department of biomedical engineering, Iran university of Science and Technology (IUST)
چکیده [English]
The study of cardiac arrhythmia is a great help for prevention of the major reason of human death. To study the arrhythmias, we need cell models that not only mimic AP’s normal behavior, but also show their abnormal activity. The usual electrophysiological models contain a lot of details and hence complicate mathematics which lowers the computational efficiency. In this paper, a minimal 2-state variables model is presented that not only simulates normal characteristics of human ventricular cells like excitability, AP morphology, restitution and effects of currents block, but also replicates early after depolarization (EAD) which is an abnormal activity of cardiac cells. The presented model is a conductance based one, incorporating two currents; inward and outward that delighting all the membrane inward and outward currents respectively. The adjustment and regulation of parameters were performed using an iterative algorithm that minimizes mean squares error between model responses and real APs. The effective range of parameters for initiation of the EAD is determined by the use of dynamical system analysis theory. The simulation results are in agreement with electrophysiological realities. The computing time of the model for an one-dimensional array of 10 cells is estimated to be between 34 to 112 times faster than some well-known electrophysiological models.
کلیدواژهها [English]
- Ventricular cell modeling
- minimal model
- cardiac action potential
- Early after depolarization
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