INNOVATIVE DESIGN FOR REAL-WORLD ENGINEERING PROBLEMS
0
50
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CRH O'Regan Orion
Tim
e (sec)
Procedure Time
2-Tailed T-Test
p << 0.01
External View
Probe
Houses suction and band
ligation mechanisms
Post-deploymentPre-deployment
• Hemorrhoids afflict 50% of people at some point
in their lives1
• 15 million annual U.S. doctor visits are due to
hemorrhoids2,3,4
• At-home hemorrhoid treatments only offer
symptom relief
• Curative treatments are limited to administration
by specialist medical doctors, such as
gastroenterologists
1Lorenzo-Rivero, S. (2009). Hemorrhoids: diagnosis and current management. Am Surg. 75(8), 635–42.
2Johanson, J. (1990). The prevalence of hemorrhoids and chronic constipation: An epidemiologic
study. Gastroenterol Clin North Am., 98(2), 380–386.
3OECD (2013). OECD Health Data: Health care utilization. OECD Health Statistics (database).
4U.S. Census Bureau, Population Division. (2016) Annual Estimates of the Resident Population: April 1,
2010 to July 1, 2015. United States Census Bureau: American Fact Finder (database).
Rubber Band Ligation (RBL) is a treatment option for
internal hemorrhoids:
Create a medical device prototype which:
• Nominally requires one insertion
• Does not require visualization or
medical grade suction
• Deploys 3 ligation bands at 120
degree increments around the rectum
to treat all local hemorrhoids
• Removes complexity of the procedure
through mechanical automation,
reducing skill requirement
• Small Business Innovation Research (SBIR)
Grant Proposal
• 510(k) FDA Clearance and Market
Introduction
• Possible licensing with larger medical
device company
• Patent coverage based on design project
prototype
The ENDSolutions team would like to thank:
• Dennis Robbins, PhD, Logan Medical
• José Rodriguez, MD, FACP, Logan Medical
• Steven Foland, PhD, University of Texas at
Dallas
• The invaluable UTDesign Staff
Thank you for your unwavering support. We
couldn’t have done it without you all!
Project Motivation Rubber Band Ligation Background Project Goals
Prototype Validation
AcknowledgementsFuture
Final Design: The Orion
Ethics Statement
Ex vivo tissue was used in place of animal
testing and human testing
Contact Team Lead
Andrew Nguyenba
The Orion Medical Device:Treating Internal Hemorrhoids through Rubber Band Ligation
Jesse Grant, Alex Lara Arvizu, Kyle Lo,
Andrew Nguyenba, Aron Torres, Lilian Zhan
Departments of Biomedical and Mechanical Engineering
Sponsored by: Logan Medical DevicesBMEN 4389/MECH 4382
Spring 2018
Trigger
Initiates band
deployment
Trigger Line
Connects
trigger to probe
Description:
• Named after the constellation because
of the 3 stars in Orion’s belt
• Ligates 3 bands simultaneously
• No visualization of hemorrhoids needed
• Disposable design for low cost
Syringe Retractor
Retracts 3 syringes simultaneously
Suction Lines
Connects
syringes to
probe
Operation:
1) Retract syringes to apply suction
2) Wait 30 seconds
3) Pull trigger to displace bands onto tissue
4) Release suction
Performance was compared using objective metrics:
CRH O’Regan
Orion
Pork Rectum with Ligation Bands
The Orion prototype was compared to the CRH
O’Regan, a current market solution.
Chi Squared analysis demonstrates
that the Orion’s performance is as
effective as the CRH in applying
ligation bands onto tissue.
∆ 3mm
3 4Scar Tissue
2
Rubber Band
1Hemorrhoid
Ligation Deviceproduces suction and places rubber band onto tissue
Inside the rectum, tissue near theinternal hemorrhoid is captured viasuction
A 5 mm outer diameter rubber band,called a ligation band, is placed ontothe rectal tissue
The captured tissue atrophies andproduces a scar
The resulting scar locally reducesblood flow, reducing hemorrhoid sizeor eliminating them altogether
1) Tissue Capture Success Rate:
Orion can generate 19% more
suction than the CRH at a 17 mL
volume change in each syringe,
with the Orion projected at 10.3
psi, and the CRH at 8.6 psi.
2) Suction Produced:
y = -3.18ln(x) - 1.2674
R² = 0.9922
-13.0
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0 5 10 15 20 25 30 35
Pressu
re (p
si)
ΔVolume (mL)
Suction Produced
CRH O'Regan
Orion
∆ Pressure
1.66 atm
The Orion captured tissue at a
lower standard deviation of 1.32
mm, compared to 1.68 mm of the
CRH, capturing 12% more tissue at
a higher precision than the CRH.
3) Tissue Capture Height:
Orion was 25% faster with a total
set up and treatment time of 131.4
seconds compared to the CRH at
181.4 seconds for three bands.
4) Procedure Time:
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
CRH O'Regan Orion
Heig
ht (m
m)
Tissue Capture Height
2-Tailed T-Test
p < 0.05
83%93%
8%8% 7%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
CRH O'Regan Orion
Tissue Capture Success Rate
Did Not Capture
Captured but disengaged
Tissue Captured
Chi Squared Test
χ2= 2.7462
p = 0.2533
Categorical variables
Independent
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