Micro-Chemical Analysis for hire / FTIR Microscopy and expert analyses / Medical Device Problem-Solving, Failure Analysis, and Reverse Engineering

1. Solving Medical Device problems using
IR Microscopy
Visible Microscopy
Part 3: Application to Medical Device issues

2. -0.30
-0.25
-0.20
-0.15
-0.10
-0.05
0.00
0.05
0.10
0.15
Absorbance
100015002000250030003500
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

3. 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?

4. 420μ x 550μ Photos of Needle’s three cut planes
The “subtle” cut

5. IR-PLAN 550μ X 420μ FOV of Point and Enhanced Image
Raw Image Obtained
Digital Enhanced Image
A “Metal Burr” is visible
on this needle point.

6. -0.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0.009
0.010
0.011
0.012
Absorbance
100015002000250030003500
Wavenumbers (cm-1)
Infrared Microscopy Provides Chemical Identification that shows
Gelled Lubricant is used on Hypodermic Needles
3.0mm x 2.3mm
550μ X 420μ
390μ x 300μ
Gel is Silicone

7. 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”

8. PET Barrels That Failed At Gate
A “Cold Slug” in an Injection Molding “Gate”
can initiate breakage at unacceptably low force

9. Gate A Gate BRidge/Valley
Cold Slugs
Blade Striations
Devices broke due to “Cold Slug” in Injection Molding Gate

10. Identification of PET Barrel Skirt
Contaminant by Micro-FTIR

11. Smudges on PET at Tip Insert of Barrels
Parting Line

12. Pre-Extracted Cellulose on PET Skirt Same Area of PET Skirt After Wiping
Streaks where Grease
was removed
Cellulose
Grease about
to be removed
PET Barrel Skirt Bloom removed for analysis

13. 5.S ilicone B BL Lube A TR,Bradmons
Kimw iped B loom in PET BBL skirt,Griffith,RE FL32
PE T BB L skirt grease,K imWiped&MC d,Castro,REFL32,2/27/09
120a2209,MICR,CE LLU LOSE ,A CCU W IPE /A L,2/244
-0.40
-0.35
-0.30
-0.25
-0.20
-0.15
-0.10
-0.05
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
Log(1/R)
1000150020002500300035004000
Wavenumbers (cm-1)
Silicone
Cellulose
Grease Found Previously
Grease Found Recently
PET Barrel Skirt Contaminant is Same as Found previously
The Difference Seen below is Cellulose from the Kimwipe.
The Grease is an Acid (1712 cm-1) and an Ester (1737 cm-1).