2300_Processbook
Transcript of 2300_Processbook
Ultrasonic Guided
Pulmonary Artery Catheter
Laura Cox
Sam Dixon
Nick Emamifar
Kathleen Rooney
1. TABLE OF CONTENTS / EXECUTIVE SUMMARY
2. BACKGROUND
3. ANALYSIS
4. PROJECT FRAMING
5. CONCEPT DEVELOPMENT
6. PROTOTYPING
Table of Contents
EXECUTIVE SUMMARY
This project is based on improving the Swan-Ganz Pulmonary Artery
(PA) catheter. The ultimate goal of the improved design was to improve
navigation in the device by adding ultrasonic sensors that would output
the diameter of the blood vessel that the tip of the catheter was
currently in.
The PA catheter is primarily used to measure blood pressure and
cardiac output. In addition, it can be used to measure thermodilution
by injecting cold saline solution into the blood vessel and measuring
the temperature change.
Ultrasonic Guided Pulmonary Artery Top Modelers: Laura Cox, Sam Dixon, Nick Emamifar, Kathleen Rooney
Overview of product historical context, user needs, demographic info,
physiological need, etc.
2-3 sentences
Background Ultrasonic Guided Pulmonary Artery Catheter
Top Modelers: Laura Cox, Sam Dixon, Nick Emamifar, Kathleen Rooney
BMED 2300 Process Book—Spring 2014
Over 5 million patients are admitted into the Intensive
Care Unit (ICU) each year. Of that number, 2.4 million
undergo at least one catheterization procedure and
360,000 will experience some kind of injury from the
catheter. Injuries can range from infections due to
prolonged catheterization, to a punctured vessel from
misplacement of the catheter.
The main issue that was found in the ICU environment
was navigation techniques which leads to physical in-
juries such as punctures to the blood vessels or mis-
placing the catheter. Typically, the ICU utilizes an x-ray
machine to guide the PA catheter. This practice is
both costly and time-consuming; and poses even
greater threats when sick or elderly patients need to
be catheterized. Another technique that is often used
in the ICU setting is having experienced nurses gauge
where they are in the body based on blood pressure
measurements taken incrementally which can be
both inaccurate and potentially dangerous.
We sought to fix this problem by adding ultrasonic
sensors to the tip of the catheter and calculating the
diameter of the blood vessel. Through this, the exact
location of the tip can be found by comparing the av-
erage blood vessel sizes, based on the subject’s
weight, to the diameter found from the calculations.
The most important equation for analyzing our
design is listed right below, which is the frequency
of the emitted sound waves. The ultrasonic
transmitter produces this sound and records the
time that it takes to reach the receiver. Frequency
of the sound wave multiplied by this time gives us
the distance to the blood vessel wall.
Analysis Ultrasonic Guided Pulmonary Artery Catheter
Top Modelers: Laura Cox, Sam Dixon, Nick Emamifar, Kathleen Rooney
BMED 2300 Process Book—Spring 2014
In the process of developing our design, we
determined the priority of our constraints. We made
many decisions based on what would best promote
our highest priorities, which were fitting in the blood
vessel and decreasing the cost of the catheter.
Project Framing Ultrasonic Guided Pulmonary Artery Catheter
Top Modelers: Laura Cox, Sam Dixon, Nick Emamifar, Kathleen Rooney
BMED 2300 Process Book—Spring 2014
Ranked constraints 1 = Highest priority
Must fit in blood vessel (< 14mm diameter) 1
Trained physicians must know how to use device 3
Must give accurate measurement of blood vessel diameter (within ±1mm)
2
Reasonably priced 1
Objective: The objective of this engineering project is to create a navigation system to give
accurate real time information of the size of the blood vessel that the catheter is currently in.
List some of the key concepts around which your team focused your
design iterations.
3-5 sentences.
State which design was chosen, and why.
1-2 sentences.
Concept Development Ultrasonic Guided Pulmonary Artery Catheter
Top Modelers: Laura Cox, Sam Dixon, Nick Emamifar, Kathleen Rooney
BMED 2300 Process Book—Spring 2014
There were three main issues with the PA catheter
that we looked into. Initially, we wanted to improve
navigation of the catheter so the users did not have to
rely on x-rays. Secondly, one doctor that we spoke
with complained that thermodilution had to be calcu-
lated indirectly; he wanted to save time by having the
catheter calculate it. Finally, we also considered rein-
forcing the balloon in case it bursts.
Our group ended up focusing on improving navigation
of the PA catheter. We hope to reduce the costs, inju-
ries, and other risks associated with this type of cathe-
terization.
Describe some of the techniques and materials used in prototyping.
3-5 sentences.
Give an overview of user’s feedback and response to your new design,
and how that affected your final solution.
Another 2-3 sentences.
Prototyping Ultrasonic Guided Pulmonary Artery Catheter
Top Modelers: Laura Cox, Sam Dixon, Nick Emamifar, Kathleen Rooney
BMED 2300 Process Book—Spring 2014
We made our initial prototypes out of Bristol board,
clay, and plastic tubing. The top picture displays the
clasping method that we considered in order to make
our device a reusable clip on sensor. Our second iter-
ation was modeled in SolidWorks and was 3D printed.
Users that we spoke with liked our idea of a reusable
sensor because this would be the cheapest option,
and hospitals are very conscious of costs. However,
our professor did not like how the sensors were stick-
ing out of the catheter tube. This led us to our second
design which contained the sensors so they would not
irritate the blood vessel they are in.
Our design eliminates the need for x-rays to
determine location. This ends up saving the user
about $45. My group was able to speak with two
nurses that regularly use a PA catheter, and they
liked that our solution saves them time and effort.
In the future, we would like to look into scaling down
our device to fit blood vessels.
Final Solution
BMED 2300 Process Book—Spring 2014
Ultrasonic Guided Pulmonary Artery Catheter
Top Modelers: Laura Cox, Sam Dixon, Nick Emamifar, Kathleen Rooney