title: Multigate transcranial Doppler ultrasound system with real-time embolic signal identification and archival.
abstract: An integrated system for acquisition and processing of intracranial and extracranial Doppler signals and automatic embolic signal detection has been developed. The hardware basis of the system is a purpose-built acquisition/processing board that includes a multigate Doppler unit controlled through a computer. The signal-processing engine of the system contains a fast Fourier transform (FFT)-based, spectral-analysis unit and an embolic signal-detection unit using expert system reasoning theory. The system is designed so that up to four receive gates from a single transducer can be used to provide useful reasoning information to the embolic signal-detection unit. Alternatively, two transducers can be used simultaneously, either for bilateral transcranial Doppler (TCD) investigations or for simultaneous intra- and extracranial investigation of different arteries. The structure of the software will allow the future implementation of embolus detection algorithms that use the information from all four channels when a single transducer is used, or of independent embolus detection in two sets of two channels when two transducers are used. The user-friendly system has been tested in-vitro, and it has demonstrated a 93.6% sensitivity for micro-embolic signal (MES) identification. Preliminary in-vivo results also are encouraging.
authors.affiliation: Medical Physics Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK. lingke.fan@le.ac.uk
authors.forename: Lingke
authors.initials: L
authors.lastname: Fan
authors.forename: Enrico
authors.initials: E
authors.lastname: Boni
authors.forename: Piero
authors.initials: P
authors.lastname: Tortoli
authors.forename: David H
authors.initials: DH
authors.lastname: Evans
mesh_terms: D000328:Adult; D000465:Algorithms; D001185:Artificial Intelligence; D003199:Computer Systems; D004453:Echoencephalography / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D016247:Information Storage and Retrieval / Q000379:methods*; D020766:Intracranial Embolism / Q000000981:diagnostic imaging*; D010363:Pattern Recognition, Automated / Q000379:methods*; D010865:Pilot Projects; D011873:Radiology Information Systems; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D018608:Ultrasonography, Doppler / Q000295:instrumentation* / Q000379:methods