title: SarcOptiM for ImageJ: high-frequency online sarcomere length computing on stimulated cardiomyocytes.
abstract: Accurate measurement of cardiomyocyte contraction is a critical issue for scientists working on cardiac physiology and physiopathology of diseases implying contraction impairment. Cardiomyocytes contraction can be quantified by measuring sarcomere length, but few tools are available for this, and none is freely distributed. We developed a plug-in (SarcOptiM) for the ImageJ/Fiji image analysis platform developed by the National Institutes of Health. SarcOptiM computes sarcomere length via fast Fourier transform analysis of video frames captured or displayed in ImageJ and thus is not tied to a dedicated video camera. It can work in real time or offline, the latter overcoming rotating motion or displacement-related artifacts. SarcOptiM includes a simulator and video generator of cardiomyocyte contraction. Acquisition parameters, such as pixel size and camera frame rate, were tested with both experimental recordings of rat ventricular cardiomyocytes and synthetic videos. It is freely distributed, and its source code is available. It works under Windows, Mac, or Linux operating systems. The camera speed is the limiting factor, since the algorithm can compute online sarcomere shortening at frame rates >10 kHz. In conclusion, SarcOptiM is a free and validated user-friendly tool for studying cardiomyocyte contraction in all species, including human.
authors.affiliation: CNRS ERL 7368, Signalisation et Transports Ioniques Membranaires, Equipe Physiologie des Cellules Cardiaques et Vasculaires, Tours, France come.pasqualin@univ-tours.fr.
authors.forename: Côme
authors.initials: C
authors.lastname: Pasqualin
authors.affiliation: CNRS ERL 7368, Signalisation et Transports Ioniques Membranaires, Equipe Physiologie des Cellules Cardiaques et Vasculaires, Tours, France.
authors.forename: François
authors.initials: F
authors.lastname: Gannier
authors.affiliation: CNRS ERL 7368, Signalisation et Transports Ioniques Membranaires, Equipe Physiologie des Cellules Cardiaques et Vasculaires, Tours, France.
authors.forename: Angèle
authors.initials: A
authors.lastname: Yu
authors.affiliation: CNRS ERL 7368, Signalisation et Transports Ioniques Membranaires, Equipe Physiologie des Cellules Cardiaques et Vasculaires, Tours, France.
authors.forename: Claire O
authors.initials: CO
authors.lastname: Malécot
authors.affiliation: CNRS ERL 7368, Signalisation et Transports Ioniques Membranaires, Equipe Physiologie des Cellules Cardiaques et Vasculaires, Tours, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bredeloux
authors.affiliation: CNRS ERL 7368, Signalisation et Transports Ioniques Membranaires, Equipe Physiologie des Cellules Cardiaques et Vasculaires, Tours, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Maupoil
mesh_terms: D000465:Algorithms; D000818:Animals; D005583:Fourier Analysis; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D009200:Myocardial Contraction / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000502:physiology*; D051381:Rats; D012518:Sarcomeres / Q000502:physiology*; D012984:Software
keywords: ImageJ plug-in; cardiomyocyte contractility; fast Fourier transform; sarcomere dynamic; video analysis