Redesign of a distal protection filter for carotid artery stenting
1 / 26

Redesign of a Distal Protection Filter for Carotid Artery Stenting - PowerPoint PPT Presentation

  • Uploaded on

University of Pittsburgh Senior Design – BioE 1160/1161. Redesign of a Distal Protection Filter for Carotid Artery Stenting. Sandeep Devabhakthuni Chenara Johnson Daphne Kontos Perry Tiberio April 18, 2005 Mentor: Ender Finol, PhD. Arterial Stenosis.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Redesign of a Distal Protection Filter for Carotid Artery Stenting' - heloise

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Redesign of a distal protection filter for carotid artery stenting

University of Pittsburgh

Senior Design – BioE 1160/1161

Redesign of a Distal Protection Filter for Carotid Artery Stenting

Sandeep Devabhakthuni

Chenara Johnson

Daphne Kontos

Perry Tiberio

April 18, 2005

Mentor: Ender Finol, PhD

Arterial stenosis
Arterial Stenosis

  • Narrowing of carotid arterial walls due to plaque build-up

    • Considered 3rd leading cause of death - Stroke

  • New, less invasive treatment:

    • Carotid Artery Angioplasty and Stenting

    • Problem: Possible embolization to the brain resulting in a stroke.

    • Solution: Embolic Protection Devices

Filter properties
Filter Properties

  • Neuroprotection (distal protection) filter

  • Polyurethane material for the basket

  • Nitinol tubing

  • Nitinol

  • Stainless steel

  • 80-140µm pore size

Problem statement
Problem Statement

  • Predicate devices include the FilterWire EX, AccuNet and Angioguard

  • These filters are 80-90% efficient

  • The goal of our design is to maximize emboli capture efficiency

FilterWire EX



Design requirements
Design Requirements

  • 99% capture efficiency

  • Lay flush with vessel lumen

  • Biocompatible

  • Durable

  • Collapsible

    • For insertion and retrieval

Economic considerations and fda regulation
Economic Considerations and FDA Regulation

  • Market Size:

    • $752M worldwide

  • Distribution

    • Medical Supply Companies

  • FDA Classification

    • Class II – Cardiovascular Diagnostic Device

Quality system considerations
Quality System Considerations

  • Manufacturability

    • Simple Design

    • Materials already used for other medical purposes

  • Human Factors

    • Easy to use for trained interventional cardiologists

      • To be determined through survey

    • Biocompatible

Initial design considerations
Initial Design Considerations

  • Incorporate the best features/materials from all current designs into our filter

  • Implement a novel feature to improve design

Proposed solution
Proposed Solution

  • Ring

  • Three struts

  • Polyurethane basket

  • 70-80µm pore size

  • Skirt

Final design
Final Design

  • Ring

  • One Strut

    • Extra Struts don’t assist in securing filter

  • Stainless steel wire

  • Nylon filter basket

    • Nylon due to material restrictions

  • Polyimide tubing to enforce nitinol ring

  • Pore size of 70-80µm

    • Captures smaller particles

  • Nylon skirt

Prototype fabrication
Prototype Fabrication

Shape nitinol into ring and reinforce with polyimide tubing

Attach stainless steel wire guidewire

Prototype fabrication1
Prototype Fabrication

Dimensions of filter Basket

Outline filter on nylon sheet

Cut out pattern and put together with polycyanoacrylate

Intended method of use
Intended Method of Use

  • Collapse filter by pulling strut

  • Insert percutaneously

  • Deploy filter by releasing strut

    • Pre-shaped to align 20° to vessel wall

  • After procedure, retrieve into retrieval sheath

Experimental methods used to test device performance
Experimental Methods Used to Test Device Performance

  • Glycerin-water solution (9:16) in flow loop

  • Insert filter into loop

  • Set peristaltic flow to 150 mL/min

  • Inject embolic beads

  • Run for 5 minutes

  • Weigh beads passed and collected by filter

Peristaltic Flow Pump


Glycerin/Water solution (9:16)

Inline filter

Point of Filter Deployment

Length = 20 cm

Insertion Point of particles

Schematic of Flow Loop

Insertion Point of Filter (one-way valve)

Data analysis
Data Analysis

  • Embolic capture efficiency determined by:

  • ezANOVA

    • Between- and In-group comparison

  • Student’s Paired t-test

Experimental results
Experimental Results

Trial 1: 98% capture efficiency!

Filter comparison chart
Filter Comparison Chart

*The modified capture efficiency data is presented here


  • Nitinol ring cracked during trial 2

  • Bottom of filter tore during trial 6

  • Filters are designed for one time use only

  • Poor results due to:

    • Placement of filter

    • Retrieval mechanism

Competitive analysis for prototype i
Competitive Analysis for Prototype I

  • Strengths

    • Reduced pore size

      • 74 microns compared to 80 – 120 micron range of filters currently on the market

    • Skirt

      • Assists in maximizing capture efficiency

    • Deeper basket

      • Prevent loss during retrieval of filter

Competitive analysis for prototype i1
Competitive Analysis for Prototype I

  • Weaknesses

    • Non-collapsible filter

    • Non functional delivery or retrieval method

    • Not a 1:1 scale


  • Redesign flow loop to include:

    • Pressure Transducers

    • Latex Tubing

  • Redesign a second prototype to include:

    • Develop a deployment/retrieval mechanism

    • Use polyurethane as the filter basket material

    • Use nitinol tubing


  • Dr. Ender Finol

  • Sanna Gaspard

  • Mark Gartner

  • Special thanks to Drs. Hal Wrigley and Linda Baker whose generous gift made this project work possible

  • University of Pittsburgh, Department of Bioengineering

  • Carnegie Mellon University