ULTRASONIC SURGICAL INSTRUMENTS: A MULTI-VARIATE STUDY FOR CUTTING-RATE EFFECTS

Bibliographic Details
Main Author: VAITEKUNAS, JEFFREY J.
Language:English
Published: University of Cincinnati / OhioLINK 2003
Subjects:
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=ucin1052935131
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-ucin10529351312021-08-03T06:09:02Z ULTRASONIC SURGICAL INSTRUMENTS: A MULTI-VARIATE STUDY FOR CUTTING-RATE EFFECTS VAITEKUNAS, JEFFREY J. ultrasound surgery medical device tissue cutting Langevin stack In spite of the proven efficacy and safety of ultrasonic surgical systems, the mechanisms for cutting and coagulation are not well understood. Preferred operating parameters and ranges should be used if clinical benefit can be shown. Therefore this research was designed to determine whether frequency, normal force, velocity and blade shape affect the cut-rate of an ultrasonic surgical instrument. Test velocities covered the range available from current ultrasonic surgical systems. Three values for normal force were selected based on previous testing. A low value corresponded to a "light" touch typically applied in fine dissection between tissue planes, and a heavy value typically used in skin incisions such as a laparotomy. Two specimens were chosen for evaluation: wax and liver. The basic behaviors of the observed cut-rates obtained at 55.5 kHz with a 2.1 mm diameter round blade were similar for wax and liver. Using analysis of variance (ANOVA), normal force, ultrasonic velocity and their first order interaction are shown to significantly affect cut-rate up to 5 N in wax and 2.5 N in liver. In wax, cut-rate is shown to be independent of frequency, and in liver the data indicate that cut-rate is independent of frequency, but are not sufficient to draw a statistical conclusion. In liver above a threshold, cut-rate increases significantly and depends on blade shape. A model for wax cutting was developed based on melting and removal of wax. Several assumptions were made and two parameters were determined by a regression. Still, the model predictions were accurate for the data on which the regression was performed. The model also predicts with reasonable accuracy the behavior observed at other frequencies for other blade shapes. The model can certainly be improved by more rigorous development; nonetheless, it does demonstrate the basic mechanisms involved in wax cutting. The results from the liver experiments and data analysis suggest that much more work is needed to accurately determine the underlying mechanisms of complex behavior of cutting tissue. The outcome of this research on liver cutting is the identification of promising directions for future research. 2003-07-07 English text University of Cincinnati / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=ucin1052935131 http://rave.ohiolink.edu/etdc/view?acc_num=ucin1052935131 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic ultrasound
surgery
medical device
tissue cutting
Langevin stack
spellingShingle ultrasound
surgery
medical device
tissue cutting
Langevin stack
VAITEKUNAS, JEFFREY J.
ULTRASONIC SURGICAL INSTRUMENTS: A MULTI-VARIATE STUDY FOR CUTTING-RATE EFFECTS
author VAITEKUNAS, JEFFREY J.
author_facet VAITEKUNAS, JEFFREY J.
author_sort VAITEKUNAS, JEFFREY J.
title ULTRASONIC SURGICAL INSTRUMENTS: A MULTI-VARIATE STUDY FOR CUTTING-RATE EFFECTS
title_short ULTRASONIC SURGICAL INSTRUMENTS: A MULTI-VARIATE STUDY FOR CUTTING-RATE EFFECTS
title_full ULTRASONIC SURGICAL INSTRUMENTS: A MULTI-VARIATE STUDY FOR CUTTING-RATE EFFECTS
title_fullStr ULTRASONIC SURGICAL INSTRUMENTS: A MULTI-VARIATE STUDY FOR CUTTING-RATE EFFECTS
title_full_unstemmed ULTRASONIC SURGICAL INSTRUMENTS: A MULTI-VARIATE STUDY FOR CUTTING-RATE EFFECTS
title_sort ultrasonic surgical instruments: a multi-variate study for cutting-rate effects
publisher University of Cincinnati / OhioLINK
publishDate 2003
url http://rave.ohiolink.edu/etdc/view?acc_num=ucin1052935131
work_keys_str_mv AT vaitekunasjeffreyj ultrasonicsurgicalinstrumentsamultivariatestudyforcuttingrateeffects
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