Recent Advances in Test Bench Solutions for DES and Bio- Degradable Stents Lito Mejia, David Dingmann, Jacques Laudinet Bose Corporation 7 th European Symposium of Vascular Biomaterials ESVB 2011, May 13-14 Strassbourg, France CONFIDENTIAL
Agenda • ! A Brief History of Stent Durability Testing by Bose • ! Evolution: Multi-mode testing • ! DES :specialized testing with particle characterization • ! Validation Test data CONFIDENTIAL
A Brief History SGT’s first introduced commercially in 1995 CONFIDENTIAL
A Brief History Multi-specimen testing Generation of S/N curves CONFIDENTIAL
A Brief History Multi-Mode Testing: + Pulsatile Extension / Contraction Distention Flexion Torsion Compression Coronary Peripheral CONFIDENTIAL
Then came ! . • ! Coated Stents, Drug Eluting Stents, Biodegrable ! CONFIDENTIAL
Coating Durability – The Test CONFIDENTIAL
Coating Integrity– Bench Testing FDA Guidance Draft: • ! “The acute and chronic integrity of coating on the stent substrate should be assessed to provide reasonable assurance that the coating is able to sustain its integrity according to its design specifications. “ • ! “The Agency requests that the sponsor qualitatively and quantitatively determine whether subjecting a DES system to expansion , deployment , and repetitive cycling modalities as experienced in the clinical setting will influence the ability of the coating to interact appropriately with the stent substrate.” Today’s Chronic Durability Assumptions: • ! Minimum 9 month fatigue test (30,000,000 cycles) • ! Worst Case 10 year pulsatile fatigue test (400,000,000 cycles) • ! Pulse on a 15 mm radius bend (Static Bend) • ! Overlapped stents (Static Bend) Future? • ! repetitive cycling modalities as experienced in the clinical setting CONFIDENTIAL
ElectroForce 9210-12 DES SGT Design considerations: • ! Consistent distension • ! Performance > 9110 SGT • ! Elevated temperature capability • ! Minimize opportunities for trapped particulate • ! Minimal flow path length • ! Isolated flow paths – • ! No metal in the filtered test section of the flow loop • ! Active computer control & DAQ of: – ! Diameter controlled distension – ! Pressure controlled distension – ! Flow & temperature – ! DAQ of individual tube flow – ! Capture filter status & switching – ! All system limits and actuations Accelerated Pulsatile • ! Integrate Laser Micrometer w/control software Fatigue Test Frame • ! Diameters: 2-14 mm • ! Lengths: up to 200 mm CONFIDENTIAL
ElectroForce 9210-12 DES SGT (3) Test Configurations Particle Counting Module Removable Filter Cartridges Accelerated Pulsatile Fatigue Test Frame Particle Capture Module CONFIDENTIAL
Innovations in Technology Isolate the stents from the PowerHeads : Dual PowerHead s: CONFIDENTIAL
! Isolate the Flow over Stents Bleed port and sample installation Bleed port Inlet from bellows Diaphragm Sample Tube Mean flow port – to counting or capture CONFIDENTIAL
Flow Loop synoptic Upper Pulsatile Source Sample Flow Loop Lower Pulsatile Source CONFIDENTIAL
Flow tubes CONFIDENTIAL
Uniform Distension: design rules Diagram showing (2) PowerHeads (#110 & #112) providing (2) sided pulsatile distension to a row of mock arteries (#102) CONFIDENTIAL
Performance CONFIDENTIAL
Uniform distension: Tube to Tube Benefits: • ! Based on Proven Bose SGT Technologies • ! Bose proprietary manifolds ensure each tube distends equally (#1 = #6 = #12) • ! Multiple Tubes (12) Lower cost/stent capital equipment • ! FDA requires minimum of (1) control tube for each machine. This gives (11) useful tubes/test • ! • ! 37 C • ! Controlled Flow CONFIDENTIAL
Innovations in Technology Stent Deployment Ports Ability to connect a Tortuous Path for transition of Acute Test to Chronic Test for the same samples CONFIDENTIAL
Validation Tests To validate LO (Light Obscuration) Methodology: • ! Bolus Testing per USP 788 • ! Particle Capture • ! Sample versus Blank Tests CONFIDENTIAL
Validation Tests: Bolus Testing The chart shows actual LO results as provided by the instrument CONFIDENTIAL
Validation of LO Particle Counting CONFIDENTIAL
Validation Tests: Particle Capture CONFIDENTIAL
Particle Characterization Module (PCM) • ! Filters can be switched based on various criteria or “Triggers”. • ! Triggers set by the user: • ! Cycle count • ! Time • ! Flow rate • ! Total flow through filter • ! The system will track these and divert flow to a new filter • ! The user will be alerted when a filter is full CONFIDENTIAL
Bolus Testing:Capture confirmation Spheres captured by the filters from the bolus tests. CONFIDENTIAL
Sample Test Test Protocol: • ! Clean & Flush System – 3-4 day process • ! 37C Saline • ! 160/80 mm Hg @ 1.2 Hz for 14 days • ! Physiological U-tubes (very thin) • ! 15 mm radius • ! (2) Stents deployed in overlapped condition • ! Counting via LO (laser) inline counters CONFIDENTIAL
Sample device Test Specimen setup, deployment ports and representative particle counting as a function of time. CONFIDENTIAL
THANK YOU Questions? CONFIDENTIAL
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