Detail publikace

Kalibrace ultrazvukového systému počítačové tomografie

FILIPÍK, A. JAN, J. PETERLÍK, I. HEMZAL, D. JIŘÍK, R.

Originální název

Calibration of an Ultrasonic Computed Tomography System

Český název

Kalibrace ultrazvukového systému počítačové tomografie

Anglický název

Calibration of an Ultrasonic Computed Tomography System

Typ

článek ve sborníku

Jazyk

en

Originální abstrakt

A 3D setup for USCT has been developed at Forschungszentrum Karlsruhe (FZK), Germany [1]. The system (Figure 1) consists of 384 senders and 1536 receivers mounted on 48 transducer array systems (TAS). For the reconstruction of tomographic images, it is crucial to know the positions of individual transducers within error in the order of the wavelength magnitude; even small positioning errors (in the range of tenths of millimeters) can lead to significant degradation of image quality. With respect to the number of transducers in the system, it is unfeasible to measure the geometry manually. An auto-calibration technique, which utilizes only the internal ultrasonic signals used by the system to solve the problem, has been designed and tested. The technique is based on time-of-flight principle, similar to GPS navigation. Particularly, the time-of-flights of individual ultrasonic pulses are used for a triangulation, formulated as a minimization problem, where the to-be-minimized quantity is the sum of squares of differences between measured and estimated pulse arrival times. The to-be-determined minimization parameters are the positions and the individual time-delays of transducers. Also, the calibration of the directivity characteristics and individual efficiencies of the trasnducers has been described.

Český abstrakt

Příspěvek popisuje původní metodu geometrické kalibrace ultrazvukového systému, založenou na času letu ultrazvukových impulsů, standardně generovaných v systému. Příspěvek informoval také o přístupu ke kalibraci směrových charakteristik a individuálních účinností jednotlivých snímačů.

Anglický abstrakt

A 3D setup for USCT has been developed at Forschungszentrum Karlsruhe (FZK), Germany [1]. The system (Figure 1) consists of 384 senders and 1536 receivers mounted on 48 transducer array systems (TAS). For the reconstruction of tomographic images, it is crucial to know the positions of individual transducers within error in the order of the wavelength magnitude; even small positioning errors (in the range of tenths of millimeters) can lead to significant degradation of image quality. With respect to the number of transducers in the system, it is unfeasible to measure the geometry manually. An auto-calibration technique, which utilizes only the internal ultrasonic signals used by the system to solve the problem, has been designed and tested. The technique is based on time-of-flight principle, similar to GPS navigation. Particularly, the time-of-flights of individual ultrasonic pulses are used for a triangulation, formulated as a minimization problem, where the to-be-minimized quantity is the sum of squares of differences between measured and estimated pulse arrival times. The to-be-determined minimization parameters are the positions and the individual time-delays of transducers. Also, the calibration of the directivity characteristics and individual efficiencies of the trasnducers has been described.

Klíčová slova

ultrazvuk, ultrazvuková průzvučná tomografie, USCT, kalibrace

Rok RIV

2007

Vydáno

09.12.2007

Nakladatel

ÚTIA AVČR

Místo

Praha

Strany od

16

Strany do

16

Strany počet

1

BibTex


@inproceedings{BUT25634,
  author="Adam {Filipík} and Jiří {Jan} and Igor {Peterlík} and Dušan {Hemzal} and Radovan {Jiřík}",
  title="Calibration of an Ultrasonic Computed Tomography System",
  annote="A 3D setup for USCT has been developed at Forschungszentrum Karlsruhe (FZK), Germany [1]. The system (Figure 1) consists of 384 senders and 1536 receivers mounted on 48 transducer array systems (TAS). For the reconstruction of tomographic images, it is crucial to know the positions of individual transducers within error in the order of the wavelength magnitude; even small positioning errors (in the range of tenths of millimeters) can lead to significant degradation of image quality. With respect to the number of transducers in the system, it is unfeasible to measure the geometry manually. An auto-calibration technique, which utilizes only the internal ultrasonic signals used by the system to solve the problem, has been designed and tested. The technique is based on time-of-flight principle, similar to GPS navigation. Particularly, the time-of-flights of individual ultrasonic pulses are used for a triangulation, formulated as a minimization problem, where the to-be-minimized quantity is the sum of squares of differences between measured and estimated pulse arrival times. The to-be-determined minimization parameters are the positions and the individual time-delays of transducers. Also, the calibration of the directivity characteristics and individual efficiencies of the trasnducers has been described. 
",
  address="ÚTIA AVČR",
  booktitle="Abstracts of Contributions to 3rd International Workshop on Data-Algorithms-Decision Making, Liblice 2007",
  chapter="25634",
  edition="UTIA AVČR",
  institution="ÚTIA AVČR",
  year="2007",
  month="december",
  pages="16--16",
  publisher="ÚTIA AVČR",
  type="conference paper"
}