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Virtual instrument for experimental ultrasonic measurement
Dufek, Ladislav ; Harabiš, Vratislav (referee) ; Kolář, Radim (advisor)
This bachelor’s thesis is about usage the virtual instrument created in LabVIEW environment for measurement of ultrasonic transducers and for resulting signal scanning. It briefly describes the basics of ultra acoustic and the principles of piezoelectric transducers. Then problematic of generation and scanning signals using cards National Instruments NI-PCI 5401 and NI-PCI 5102 are explained. Subsequently an instrument is designed. This instrument is used for experimental measurement at 4 pcs engineering samples of ultrasound transducers, is painted the frequency response characteristic and determines frequency of resonance.
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Model Study of Ultrasound Effects on Fetal Development
Jaroš, Josef ; Halámek, Josef (referee) ; Hrazdíra,, Ivo (referee) ; Rozman, Jiří (advisor)
The progress in ultrasound techniques goes hand in hand with increasing of diagnostic machine acoustic outputs. Ultrasound biological effects can adversely influence the development of human fetus. Recent studies of thermal effect on biological tissues are usually based on simulation of simple ultrasound transducers. The aim of this work is to build a flexible model of diagnostic system to simulate temperature increase during fetal development. Different types of ultrasound probes were used for generation of acoustic field with simulated piezoelectric element properties. Optimized linear and phased arrays were modeled with dynamic beam steering and focus. Computer simulations were concentrated on extreme conditions in obstetric ultrasonography and 3D tissue model was compared with real ultrasound probes measurements. To detect temperature increase, the bone tissue phantom was used. Results point out potential risks for fetus with diagnostic ultrasound probes. Based on the results of this work, practical recommendations increasing safety of obstetric examinations were drawn.
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Model Study of Ultrasound Effects on Fetal Development
Jaroš, Josef ; Halámek, Josef (referee) ; Hrazdíra,, Ivo (referee) ; Rozman, Jiří (advisor)
The progress in ultrasound techniques goes hand in hand with increasing of diagnostic machine acoustic outputs. Ultrasound biological effects can adversely influence the development of human fetus. Recent studies of thermal effect on biological tissues are usually based on simulation of simple ultrasound transducers. The aim of this work is to build a flexible model of diagnostic system to simulate temperature increase during fetal development. Different types of ultrasound probes were used for generation of acoustic field with simulated piezoelectric element properties. Optimized linear and phased arrays were modeled with dynamic beam steering and focus. Computer simulations were concentrated on extreme conditions in obstetric ultrasonography and 3D tissue model was compared with real ultrasound probes measurements. To detect temperature increase, the bone tissue phantom was used. Results point out potential risks for fetus with diagnostic ultrasound probes. Based on the results of this work, practical recommendations increasing safety of obstetric examinations were drawn.
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|
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Virtual instrument for experimental ultrasonic measurement
Dufek, Ladislav ; Harabiš, Vratislav (referee) ; Kolář, Radim (advisor)
This bachelor’s thesis is about usage the virtual instrument created in LabVIEW environment for measurement of ultrasonic transducers and for resulting signal scanning. It briefly describes the basics of ultra acoustic and the principles of piezoelectric transducers. Then problematic of generation and scanning signals using cards National Instruments NI-PCI 5401 and NI-PCI 5102 are explained. Subsequently an instrument is designed. This instrument is used for experimental measurement at 4 pcs engineering samples of ultrasound transducers, is painted the frequency response characteristic and determines frequency of resonance.
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