Instron Uniaxial Tensile Testing of Suture Performance Group
- Slides: 5
Instron Uniaxial Tensile Testing of Suture Performance Group: TA 2 Aims/Objective & Hypotheses: • Uniaxial tensile testing: interrupted and running suture stitches • Determine suitability for cyclic / high stress loading • Hypotheses: • Running: more suitable for cyclic applications • Interrupted: more suitable for high-stress applications University of Pennsylvania Department of Bioengineering
Methods, Protocol & Equipment: Equipment Procedure 3 mm • Desktop Instron machine • Pneumatic 1. 5” clamps • 1/4 -inch polyethylene foam • 7 -0 Vicryl suture • Suture holder, scissors • X-acto knife • Calipers, ruler, marker pens • Digital camcorder and video software University of Pennsylvania • Sixteen 1. 5 3. 5 -inch samples • 75% depth score to 14 samples • Controls • Upper and lower bounds • 6 surrogates with each stitch type • 8 stitches • 3 mm from seam • Two-stage test • Run 1 sample to failure • Cyclic loading at 70% max • Videotape each run • Run all samples • Post-test video analysis • T-test analysis of stitch types Department of Bioengineering
Proposed Results/Findings/Deliverables: stress • Non-cyclic stress/strain curve resembling polymer: • Differentiation of stitch type maxmaximum tensile strength • Higher failure • or More cycles withstood • Stitch type tailored to epidermal region • Repetitive motion: cyclic loading ability • High epidermal stress: tensile strength • Hypothesized results • Running stitch: cyclic loading? • Interrupted stitch: tensile strength? strain University of Pennsylvania Department of Bioengineering
Potential Pitfalls: • Inconsistency in suture systems • Multiple “doctors” • Imprecise measurement • Suture tension • Surgical knots • Time limitation • Equipment shortcomings • Instron clamps • Identifying failure • Low population size Interrupted suture diagram. (Source: San Francisco General Hospital web resources. http: //sfghed. ucsf. edu/) University of Pennsylvania Department of Bioengineering
Materials and Budget & Justification: TOTAL University of Pennsylvania Department of Bioengineering