title: Multichannel data acquisition system for mapping the electrical activity of the heart.
abstract: BACKGROUND
  Details of the electrical conduction pattern of the heart are revealed to the electrophysiologist when multichannel data are used for activation mapping. Commercial electronic systems are available for simultaneous acquisition of many surface electrograms; however, the cost of these systems may be prohibitive and they can be mostly inflexible for adaptation to other research projects. Furthermore, the hardware and software design is often proprietary. In this article we describe the in-house design and implementation of a 320-multichannel acquisition system for animal electrophysiologic research.
  
  
  RESULTS
  Several modules comprise this system. The multichannel data are first preprocessed by amplification, filtering, and analog multiplexing. An algorithm for automatic adjustment of signal gains is implemented to maximize the voltage resolution and minimize noise pickup. Signals are then digitized, and sequenced to order the multichannel data and to add markers required for analysis. The digital data are streamed to archival storage media. Additionally, the electrocardiogram (ECG), blood pressure, and stimulus channel signals are stored simultaneously. Selected signals are then displayed in real-time for measurement and analysis and as a check of the system integrity. Examples of multielectrode arrays and surface recordings are provided. Costs for building such a system are estimated.
  
  
  CONCLUSIONS
  Multichannel data acquisition systems that are designed and constructed in-house have several advantages over turnkey commercial systems, including the potential for considerable cost savings, flexibility in acquiring data, and the ability to subsequently add additional components.
authors.affiliation: Department of Pharmacology, Columbia University, New York, NY 10032, USA. ciaccio@columbia.edu
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Ciaccio
authors.forename: Adam E
authors.initials: AE
authors.lastname: Saltman
authors.forename: Oscar M
authors.initials: OM
authors.lastname: Hernandez
authors.forename: Reidar J
authors.initials: RJ
authors.lastname: Bornholdt
authors.forename: James
authors.initials: J
authors.lastname: Coromilas
mesh_terms: D000703:Analog-Digital Conversion; D000818:Animals; D004285:Dogs; D004566:Electrodes; D004582:Electronics, Medical; D022062:Electrophysiologic Techniques, Cardiac / Q000295:instrumentation*; D004867:Equipment Design; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*