東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Flat, electronically steered lambda/...

Ellens, Nicholas Pieter Kennedy.

Linked to FindBook

Google Book

Amazon

博客來

Flat, electronically steered lambda/2-spaced phased arrays for focused ultrasound surgery.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Flat, electronically steered lambda/2-spaced phased arrays for focused ultrasound surgery./
Author:	Ellens, Nicholas Pieter Kennedy.
Description:	134 p.
Notes:	Source: Dissertation Abstracts International, Volume: 76-12(E), Section: B.
Contained By:	Dissertation Abstracts International76-12B(E).
Subject:	Medical imaging. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3715845
ISBN:	9781321941623

Flat, electronically steered lambda/2-spaced phased arrays for focused ultrasound surgery.
Ellens, Nicholas Pieter Kennedy.

Flat, electronically steered lambda/2-spaced phased arrays for focused ultrasound surgery. - 134 p.

Source: Dissertation Abstracts International, Volume: 76-12(E), Section: B.

Thesis (Ph.D.)--University of Toronto (Canada), 2015.

One of the promising applications of non-invasive focused ultrasound surgery is the treatment of women with uterine fibroids. Without any incision, fibroids can be thermally ablated in an outpatient procedure allowing patients to return to normal activity within two days.

ISBN: 9781321941623Subjects--Topical Terms:

3172799
Medical imaging.

Flat, electronically steered lambda/2-spaced phased arrays for focused ultrasound surgery.
LDR:03271nmm a2200325 4500 001 2077530
005 20161114130323.5
008 170521s2015 ||||||||||||||||| ||eng d
020 $a 9781321941623
035 $a (MiAaPQ)AAI3715845
035 $a AAI3715845
040 $a MiAaPQ $c MiAaPQ
100 1 $a Ellens, Nicholas Pieter Kennedy. $3 3193041
245 1 0 $a Flat, electronically steered lambda/2-spaced phased arrays for focused ultrasound surgery.
300 $a 134 p.
500 $a Source: Dissertation Abstracts International, Volume: 76-12(E), Section: B.
500 $a Adviser: Kullervo Hynynen.
502 $a Thesis (Ph.D.)--University of Toronto (Canada), 2015.
520 $a One of the promising applications of non-invasive focused ultrasound surgery is the treatment of women with uterine fibroids. Without any incision, fibroids can be thermally ablated in an outpatient procedure allowing patients to return to normal activity within two days.
520 $a Despite its benefits and potential, the adoption of focused ultrasound surgery has been slow. Current applications of the technique are slow, exclude many women for physiological reasons, and rely on expensive MR-guidance. This thesis describes the development of a new type of focused ultrasound therapy array designed to reduce treatment time consisting of elements with half-wavelength spacing arranged in a flat array. Using simulations, this thesis will discuss the benefits and consequences of sparse phased arrays (a common technique to reduce complexity), and explore the ability of a flat, half-wavelength-spaced phased array to ablate fibroids efficiently and safely. Finally, preliminary feasibility results with a device prototype will be presented in vitro and in vivo..
520 $a The first simulation study presented here compares flat phased arrays with half-wavelength inter-element spacing with randomly-spaced sparse arrays with element populations of 75%, 50%, and 25%. Though even the very sparse (and least complex) arrays were able to perform comparable ablations, it was found that they required much more power, which was preferentially deposited in the near-field of the transducer which could extend treatment time. The second simulation study claims that a half-wavelength-spaced array at 500 kHz could perform a realistic fibroid ablation as close as 40 mm from the spine without the need for any mechanical translation. Five simulated treatments were performed at an average treatment rate of 90 +/- 20 mL/hr.
520 $a Finally, this thesis reports preliminary evidence that it is feasible to construct an array of over 1000 individually-controlled elements, arranged in 64-element blocks with half-wavelength element spacing, producing acoustic powers of over 100 W. In vitro, this array was shown to be capable of steering to its edge losing only 24% to 25% of its peak pressure. Extrapolating, this prototype suggests that it is feasible to construct a 6000+ element array suitable for efficient uterine fibroid ablation.
590 $a School code: 0779.
650 4 $a Medical imaging. $3 3172799
650 4 $a Biophysics. $3 518360
650 4 $a Medicine. $3 641104
690 $a 0574
690 $a 0786
690 $a 0564
710 2 $a University of Toronto (Canada). $b Medical Biophysics. $3 3181600
773 0 $t Dissertation Abstracts International $g 76-12B(E).
790 $a 0779
791 $a Ph.D.
792 $a 2015
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3715845