Advanced

Mekanisk konstruktion av ultraljudsgivare

Engman, Calle and Andersson, Christian (2010) MMK820 20102
Product Development
Abstract
This master thesis follows the process of a product design and development project concerning the mechanical design of an ultrasound sensor. The project giver is the global medical technology company Gambro specialized in products for dialysis. The mentioned ultrasound sensor is a level detector from Gambro’s hemodialysis ma-chines, designed to prevent the occurrence of air embolism.
Air that for some reason has found its way in to the blood line of the hemodialysis machine is separated in the venous drip chamber. To ensure its function the blood level in the drip chamber needs to remain over a certain point, sensed by the level detector, and if it drops too low an alarm is issued. Piezoelectric crystals, one on each side of the drip... (More)
This master thesis follows the process of a product design and development project concerning the mechanical design of an ultrasound sensor. The project giver is the global medical technology company Gambro specialized in products for dialysis. The mentioned ultrasound sensor is a level detector from Gambro’s hemodialysis ma-chines, designed to prevent the occurrence of air embolism.
Air that for some reason has found its way in to the blood line of the hemodialysis machine is separated in the venous drip chamber. To ensure its function the blood level in the drip chamber needs to remain over a certain point, sensed by the level detector, and if it drops too low an alarm is issued. Piezoelectric crystals, one on each side of the drip chamber, send and receive the signal. If there is blood in the active area the signal is transmitted to the receiver, while air reflects the signal.
The level detector is sensitive to a variety of factors affecting the acoustic coupling, which may lead to false alarms annoying the user and patient. The goal of the project is to analyse these factors and propose a new mechanical design for the level detector, minimizing the impact on the received signal.
Testing and analysis was performed both on the original product and on different prototypes. The analysis showed that some of the most important factors are the dif-ferent drip chambers, movement during treatment and an increasing coupling area with time.
A number of different design concepts were developed and evaluated, leaving one concept to be designed in detail. This concept is similar to the original level detector, but has rigid sensors creating a bigger pressure towards the drip chamber, which has a positive effect on the acoustic coupling factors.
Comprehensive testing was performed on a prototype of the new concept, comparing it to the original level detector. It was concluded that most of the important factors were improved by the new concept but that some problems remain. In particular the varying dimensions of the different drip chambers cause problems and the received signal still differs between them. (Less)
Please use this url to cite or link to this publication:
author
Engman, Calle and Andersson, Christian
supervisor
organization
course
MMK820 20102
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Product development, ultrasound sensor, acoustic coupling, Gambro, hemodialysis
language
Swedish
id
1737201
date added to LUP
2010-12-07 14:57:10
date last changed
2010-12-07 14:57:10
@misc{1737201,
  abstract     = {This master thesis follows the process of a product design and development project concerning the mechanical design of an ultrasound sensor. The project giver is the global medical technology company Gambro specialized in products for dialysis. The mentioned ultrasound sensor is a level detector from Gambro’s hemodialysis ma-chines, designed to prevent the occurrence of air embolism.
Air that for some reason has found its way in to the blood line of the hemodialysis machine is separated in the venous drip chamber. To ensure its function the blood level in the drip chamber needs to remain over a certain point, sensed by the level detector, and if it drops too low an alarm is issued. Piezoelectric crystals, one on each side of the drip chamber, send and receive the signal. If there is blood in the active area the signal is transmitted to the receiver, while air reflects the signal.
The level detector is sensitive to a variety of factors affecting the acoustic coupling, which may lead to false alarms annoying the user and patient. The goal of the project is to analyse these factors and propose a new mechanical design for the level detector, minimizing the impact on the received signal.
Testing and analysis was performed both on the original product and on different prototypes. The analysis showed that some of the most important factors are the dif-ferent drip chambers, movement during treatment and an increasing coupling area with time.
A number of different design concepts were developed and evaluated, leaving one concept to be designed in detail. This concept is similar to the original level detector, but has rigid sensors creating a bigger pressure towards the drip chamber, which has a positive effect on the acoustic coupling factors.
Comprehensive testing was performed on a prototype of the new concept, comparing it to the original level detector. It was concluded that most of the important factors were improved by the new concept but that some problems remain. In particular the varying dimensions of the different drip chambers cause problems and the received signal still differs between them.},
  author       = {Engman, Calle and Andersson, Christian},
  keyword      = {Product development,ultrasound sensor,acoustic coupling,Gambro,hemodialysis},
  language     = {swe},
  note         = {Student Paper},
  title        = {Mekanisk konstruktion av ultraljudsgivare},
  year         = {2010},
}