Publications – Stent Testing

Medical Device Testing

The Comprehensive Validation of a Stent Coating Durability Tester

by Dynatek Labs | RMBS 2009 | Publications, Particle Counting

Ramesh R, Conti JC, Strope ER

RMBS 2009

Keywords: stent, coating, durability, particles, counting, validation

This study addresses the need to develop an instrument and supporting protocol to evaluate the tendency for a bare or drug coated stent to shed particles into the vasculature of a patient. The resultant experiments demonstrated that two types of instruments each properly detected, sized and counted better than 90% of the injected calibration particles within four minutes.

Comparison of Radial Expansion of Stents

by Dynatek Labs | RMBS 2008 | Publications, Compliance, High Speed Photography, Silicone Mock Arteries, Stent Testing

Ramesh R, Conti JC, Strope ER, Thompson M, Price KS, Murray D

RMBS 2008

Keywords: radial expansion, stent durability, deflection, mock vessels, coronary artery

Coronary artery disease results in hardening of the arteries. The main reason is that cholesterol and plaque build up on the inner walls of the arteries. This results in restricting the blood flow to the heart causing injury to the heart muscle. Recently, non-surgical processes are being used to open up …

A Comprehensive Protocol and Procedural Considerations Designed to Evaluate the Shedding of Particles from Drug Eluting Stents

by Dynatek Labs | MPMD 2007 | Publications, Particle Counting

Conti JC, E. Strope, R. Ramesh, C. Conti, A. Watkins

MPMD 2007

The American Society for Testing and Materials (ASTM) [35] and Association for the Advancement of Medical Instrumentation (AAMI)/ International Organization for Standardization (ISO) [36] committees have drafted or passed standards [38, 39] to address the release of particulates into the vasculature by drug eluting stents during deployment and implantation. A new AAMI…


Evaluating the in situ Loading and Accelerated Durability of Barbs Located on Bifurcated Aorto-Iliac Stent-Grafts

by Dynatek Labs | RMBS 2000 | Publications, Barb Stent, Stent Testing

Biomedical Science Instrumentation, 36, pp. 93-98, (2000)

James C. Conti, Elaine R. Strope

RMBS 2000

Keywords: aorto-iliac, stent-graft, durability, fatigue, stent, accelerated

A special three-part protocol has been generated for the isolated durability testing of stent barbs. This triple protocol includes an initial evaluation on a cardiovascular duplicator to determine the loading per barb that occurs during normal flow…

The Durability Testing of Porous Bifurcated Stent/Grafts Without Restricting Leakage

by Dynatek Labs | SFB 2000 | Publications, Stent Testing


James C. Conti, Elaine R Strope, Donald J. Rohde, Richard Carp, Steven Kulan

SFB 2000

The durability or fatigue testing of porous vascular grafts or stent/grafts has, along with the standard problems associated with accelerated testing, the obvious additional disadvantage that the testing fluids are constantly leaked through the wall, thereby reducing the volume of testing fluid available. In the past the most common approach to this problem was to use a material to restrict the leakage of the fluid out of the …

The High Frequency Testing of Vascular Grafts and Vascular Stents: Influence of Sample Dimensions of Maximum Allowable Frequency

by Dynatek Labs | RMBS 1999 | Publications, Stent Testing

Biomedical Science Instrumentation, 35, pp. 339-346, (1999)

J.C. Conti, E.R. Strope, K.S. Price, L.M. Goldenberg

RMBS 1999

Keywords: Compliance, grafts, frequency, radial, testing, accelerated, durability, fatigue, stents, catheters

There are over four dozen companies developing new products for the lucrative vascular graft and vascular stent markets. We have been studying the procedures…

Current Trends in the Durability Testing of Medical Products

by Dynatek Labs | SFB Workshop 1999 | Publications, Stent Testing

James C. Conti, Elaine R. Strope

SFB Workshop 1999

The general theory and approach to high speed testing will be reviewed. This year’s workshop will focus primarily on those testing techniques that have been developed or upgraded during the last twelve months. In particular, the latest approaches to the testing of stents, stent/grafts, septal defect closure devices, bifurcated grafts, left ventricular assist devices, adhesive bonds, and packaging will be reviewed. This workshop will give attendees a broad understanding of the issues that must be considered when designing and carrying out high speed dynamic testing …

High Frequency Testing of Grafts and Mock Arteries for Stents: Influence of Testing Frequency on Durability

by Dynatek Labs | SFB 1999 | Publications, Stent Testing

25th Annual Meeting of the Society for Biomaterials, Transaction, 403, (1999)

James C. Conti, Elaine R. Strope, Karen Price

SFB 1999

There is little precedent in the medical product development world for the recent introduction of new product ideas associated with the developers of stents. Product developers face the competing pressures of the need for verifiable, long term durability testing on these products and the need to minimize time to market. Although there has…

High Frequency Testing of Nitinol Stent Material

by Dynatek Labs | SFB 1999 | Publications, Stent Testing

James C. Conti, Elaine R. Strope, Ray Gregory

25th Annual Meeting of the Society for Biomaterials, Transactions, 398, (1999)

SFB 1999

The use of Nitinol in implantable medical products has been increasing at a rapid rate over the last several years. There are two reasons for this: The shape memory properties and the superelasticity which make it highly convenient for the deployment of several medical products, including stents and heart valves. Because of the need for reliable and well-designed durability/fatigue experiments on these products…

Sources of Error in Monitoring High Speed Testing of Vascular Grafts

by Dynatek Labs | RMBS 1998 | Publications, Stent Testing

Biomedical Science Instrumentation, 34, pp. 240-245, (1998)

J. C. CONTI, Ph.D., E. Strope, Ph.D., and K. Price

RMBS 1998

Keywords: Compliance, tubing, grafts, mechanical, frequency, radial, testing, accelerated, durability, fatigue

Mechanical compliance issues are increasingly important in the design, testing, and manufacture of vascular grafts. This has to do with the observed relationship between long-term patentcy of implanted grafts and…

High Speed Vascular Graft Testing: The Influence of Varying Structural Characteristics of Polyurethane and Natural Rubber Arterial Substitutes

by Dynatek Labs | SFB 1997 | Publications, Stent Testing

Conti, J.C., Strope, E.R., Rohde, D.J., and Spence, L.D.

SFB 1997

As the arrival of an efficacious arterial substitute (vascular graft) and vascular stent becomes more imminent, a thorough understanding of how their properties influence how they must be tested is critical. A challenging yet critically important issue is the ability to evaluate the long term durability characteristics of a device in a reasonable period of time. The obvious solution is to test at an accelerated rate or frequency.

Barbs on Vascular Stents: A Three-Part Protocol to Evaluate Durability

by Dynatek Labs | SFB 1997 | Publications, Barb Stent, Stent Testing

Conti, J.C., Strope, E.R., Rohde, D.R.

SFB 1997

Dozens of new stent designs are under evaluation to address the problems of occlusion, reocclusion, and aneurysm formation. A common design element utilizes small barbs or projections from the stent that pierce the adjacent vessel wall and anchor the stent or graft/stent combination.

Recently, a barb-containing stent that had supposedly passed durability testing when evaluated using currently accepted accelerated protocols failed in vivo due to barb breakage. These failures have resulted in the need for protocols to specifically…

Design Considerations for the In Vitro Testing of Cardiovascular Prosthesis

by Dynatek Labs | ISAO 1986  | Publications, Heart Valve Testing, Stent Testing

Elaine R. Strope, Ph.D.

ISAO 1986 

Prosthetic cardiovascular devices are unique in that, in addition to the requirement of functioning for nearly a billion cycles or more, failure can result in death of the user. As a result, in vitro testing becomes critically important. The special considerations in design of instrumentation to test these devices will be reviewed and examples of data generated will be given.

For nearly a decade, personnel now associated with Dynatek …

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