micro ftir2 medical-devices
TRANSCRIPT
Solving Medical Device problems using
IR Microscopy
Visible Microscopy
Part 3: Application to Medical Device issues
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Abs
orba
nce
1000 1500 2000 2500 3000 3500 Wavenumbers (cm-1)
Silicone Lubricated Gasket
Less Silicone After Surface Scraped
No Silicone After Acetone Wash:Silicate-filled rubber polymer
ATR Spectra of Surface of IR-Opaque Rubber
2.3mm x 3.0mm Photos of an Insulin Needle Point
The Technology of a Needle Point
What can we learn with a fast analysis?
420μ x 550μ Photos of Needle’s three cut planes
The “subtle” cut
IR-PLAN 550μ X 420μ FOV of Point and Enhanced Image
Raw Image Obtained
Digital Enhanced Image
A “Metal Burr” is visibleon this needle point.
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rban
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W avenum ber s ( cm - 1)
Infrared Microscopy Provides Chemical Identification that showsGelled Lubricant is used on Hypodermic Needles
3.0mm x 2.3mm
550μ X 420μ
390μ x 300μ
Gel is Silicone
8.5mm X 11.2mm
Hoop Stress cracking
Polyetherimide (PEI) Stopcock Outerbody resists splitting caused by fatty Feeding Liquids but costs more than Polycarbonate (PC) (which is cracked by combination of fats and stress). Stopcock InnerBody is pressed into Outerbody and this strong PEI polymer can still crack if it can’t stretch enough under this “Hoop Stress”tensile load (vs PC which is very stiff but also very TOUGH/RUBBERY).
Engineering Resins: ESCR vs “Hoop Stress Failures”
PET Barrels That Failed At GateA “Cold Slug” in an Injection Molding “Gate”
can initiate breakage at unacceptably low force
Gate A Gate B Ridge/Valley
Cold Slugs
Blade Striations
Devices broke due to “Cold Slug” in Injection Molding Gate
Identification of PET Barrel SkirtContaminant by Micro-FTIR
Smudges on PET at Tip Insert of Barrels
Parting Line
Pre-Extracted Cellulose on PET Skirt Same Area of PET Skirt After Wiping
Streaks where Greasewas removed
Cellulose
Grease aboutto be removed
PET Barrel Skirt Bloom removed for analysis
5 .S ilic o n e B B L L u b e A T R ,B ra d m o n sK im w ip e d B lo o m in P E T B B L s k irt,G riffith ,R E F L 3 2P E T B B L s k irt g re a s e ,K im Wip e d & M C d ,C a s tro ,R E F L 3 2 ,2 /2 7 /0 91 2 0 a 2 2 0 9 ,M IC R ,C E L L U L O S E ,A C C U WIP E /A L ,2 /2 4 4
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Lo
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10 00 15 00 20 00 25 00 30 00 35 00 40 00 Wa v e nu mb ers (c m-1)
Silicone
Cellulose
Grease Found Previously
Grease Found Recently
PET Barrel Skirt Contaminant is Same as Found previouslyThe Difference Seen below is Cellulose from the Kimwipe.
The Grease is an Acid (1712 cm-1) and an Ester (1737 cm-1).