title: A new real-time mapping system to detect microscopic cardiac excitation patterns.
abstract: A new fast, high-resolution measurement system has been developed to analyze the propagation of cardiac excitation on a microscopic scale. The instrument uses a microsensor array to detect microscopic excitation patterns at the cardiac surface. Ninety-six epicardial signals are recorded simultaneously with 14-bit resolution at 200-kHz samples per second per channel. The system operates like a digital oscilloscope. Preprocessing routines (offset, gain, and triggering) are executed within a sampling interval of 5 microseconds by 48 digital signal processors. Analog-to-digital (A/D) converters are provided with 12 Mb of buffer memory, allowing continuous recording of up to 64-k samples x 96 channels. The recorded dataset is transferred rapidly (8 Mb/sec) to the memory of the integrated computer system via VXIbus. Analysis and visualization of the propagating excitation are computed by custom-designed software. The performance of the system allows recording as well as visualization of the cardiac excitation spread in a beat-to-beat manner.
authors.affiliation: Institut fuer Medizinische Physik und Biophysik, Karl-Franzens-Universitaet Graz, Austria.
authors.forename: G
authors.initials: G
authors.lastname: Mohr
authors.forename: E
authors.initials: E
authors.lastname: Hofer
authors.forename: G
authors.initials: G
authors.lastname: Plank
mesh_terms: D000703:Analog-Digital Conversion; D000818:Animals; D018780:Body Surface Potential Mapping / Q000295:instrumentation* / Q000379:methods; D004553:Electric Conductivity; D004567:Electrodes, Implanted; D004867:Equipment Design; D006168:Guinea Pigs; D006329:Heart Conduction System / Q000502:physiology; D010210:Papillary Muscles / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013499:Surface Properties