Download - Patent Ductus and Vascular Occlusion Devices
Patent Ductus and Vascular Occlusion Devices
Michelle Carlsen
Elaine Isom
Brad Klosterman
Ornob Roy
Advisor: Dr. Thomas Doyle
Project Definition
• Objective: Design, build, and market an occlusion device which can be used to close the Patent Ductus and cylindrical vasculature
• Presentation topics: – Background
– solution
– accomplishments
– current status
– future plans
Background:Patent Ductus
• Condition affecting Infants/Children
• ~ 10-12% of congenital defects• 40 cases/yr at Vanderbilt• > 20,000 nationwide• Connection btw pulmonary
artery and aorta
Background:General Vasculature
• Less common than PDA• Cylindrical shape• Reroute blood flow• Isolate defective vasculature• Impede significant flow
PDA/ Vascular Conditions
• Diagnosis:– Heart murmur
– Extreme weight loss
– Stunted growth
– Irregular blood flow*
* General vasculature
• Consequences:– Irreversible pulmonary-
vascular disease
– Congestive heart failure
– Hemorrhaging (e.g. diabetics, post-surgical patients)*
Requirements
• Biocompatible
• Quick endothelialization (1-2months)
• Delivered through a catheter < 2mm diameter
• Simple, Retrievable
• Inexpensive
• Various size (2 to 10mm)
• Form-fitting
• Maximum effectiveness
– Internal device– Complete closure
– Standard catheter size
– Minimum training– Cost effective - comparatively– Universal Device– Immovable and closure– No leakage
Current Solutions
• Endomethiasin
– initial form of treatment
– steroid medicine (vasoconstrictor)
– restricted to premature infants
• Suturing
– effective
– invasive, long recovery
• Coils– inexpensive– not form fitting
• Titanium devices– form fitting– very expensive
• Ultrasonic Devices– non-invasive– high-intensity– not human tested
Accomplishments
• Identification of associated diseases
• Analysis of previous device designs
• Studies in biocompatible materials (Prof. Kinser, Material Sciences)
• Fluoroscopy viewing
• SDRC I-DEAS CAD/CAM modeling
• Began mock circulation system
I-DEAS Modeling
• Goal– allow for quick and
accurate prototyping
– marketing and visualization
Current Status
• 3D modeling using SDRC I-DEAS
• Material search
• 4 design concepts
• Large scale simulation: drawings, materials, construction
Design 1
Advantages:
•adjust on contact
•expandable polymer
•form-fitting (PDA & general)
Disadvantages:
•FDA
•expensive (polymer & wire
•retrievable??
Design 2
Advantages:
•form-fitting (PDA & general)
•collapsible (>500%)
•endothelialize quickly
•inexpensive
Disadvantages:
•complex
•possible limited retrieval
Design 3
• Advantages
– very rigid
– easily retrievable
– adjustable
• Disadvantages– difficult to maneuver
– expensive
Design 4
Advantages:
•form-fitting (PDA & general)
•retrievable
•simple
•inexpensive
Disadvantages:
•expansion limitations??
•Two materials
Material Search
• Zotefoams– plastazote foam (polyethylene)
• Medicell– medical sponges
• Titanium/wire material
• Thrombosing fibers
• Polyurethane foam (earplugs)
• Polyurethane that is modified with lower alkyl Sulfonate and L(L-glutamic acid co L-leucine)– biocompatible, used in surgical implantations and blood contacting
procedures
Suitable Materials
• Hydromer– Medicell Hydrophilic Open Cell Medical Foam– consists of polyurethane and
polyvinylpyrrolidone polymers
• Foamex– Functional Flexibility
• Titanium Feet
Simulation
Echigo, S et al. “ Development of New Transvenous Patent Ductus Arteriosis Occlusion Technique Using a Shape Memory Polymer.” ASAIO Transactions: 1990 pg M197.
Simulation Protocol
• Large scale
• Fluid:– water glucose mixture– pig’s blood
• Pulsatile Pump
• Latex Tubing (18 flexitube)
• Plastic PDA (conical 2mm opening)
Division of Labor
• Elaine/Michelle:– PDA design
– material search
– literature analysis/search
• Ornob/Brad:– Vascular Occluder Design
– modeling using I-DEAS
– simulation design idea, construction
• Group:– device design ideas
– large scale prototypes
– designsafe analysis
Future Plans
• Decide on final design
• Acquire materials for design
• Continue meeting with Dr. Doyle
• Designsafe analysis
• Large scale replication
• Patent