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



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



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



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



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


Ultrasonic Guided Pulmonary Artery Catheter


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