1 / 41

OTTER & AquaFlux

OTTER & AquaFlux. Perry Xiao London South Bank University Photophysics Research Centre & Biox Systems Ltd University Spin-out Company. Plan. 1. OTTER Fundamentals 2. OTTER & SC Hydration 3. AquaFlux Fundamentals 4. AquaFlux Applications. OTTER Overview.

charde-deleon
Download Presentation

OTTER & AquaFlux

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. OTTER&AquaFlux Perry Xiao London South Bank University Photophysics Research Centre & Biox Systems Ltd University Spin-out Company

  2. Plan 1. OTTER Fundamentals 2. OTTER & SC Hydration 3. AquaFlux Fundamentals 4. AquaFlux Applications

  3. OTTER Overview (Opto-Thermal Transient Emission Radiometry)

  4. OTTER – The Spectroscopic Dimension OTTER Selectivity:- 1. Excitation 2. Thermal Emission Wavelength determines:- 1. Absorbing Species 2. Penetration Depth OTTER requires STRONG Absorption !

  5. OTTER Fixed & Fibre Optics Fixed Optics Fingers, Hands & Volar Forearm Mobile Measurement Head Any skin site

  6. Plan 1. OTTER Fundamentals 2. OTTER & SC Hydration 3. AquaFlux Fundamentals 4. AquaFlux Applications

  7. OTTER Hydration Measurement Excitation @ 2.94µm:- H2O Penetration ~0.8µm Emission @ 13µm:- H2O Penetration ~3.3µm

  8. OTTER Signal Analysis 1

  9. OTTER Signal Analysis 2 Mean SC Hydration Model SC Hydration Gradient Model

  10. Example 1: Mean SC Hydration

  11. Example 2: SC Hydration Gradient

  12. Example 2: SC Hydration Gradient Remove the time dimension by correlating Surface Hydration with Hydration Gradient. This analysis provides a measure of SC water holding capacity

  13. Example 3: 3D Hydration Mapping Volar forearm/wrist area.

  14. Summary of OTTER Capabilities • SC Hydration Depth Profiling • SC Water-holding & Binding Energy Measurement • SC Thickness & Swelling Measurement • SC Renewal Time Measurement • Epidermis Pigment Depth Profiling • Epidermis Thickness Measurement • Trans-dermal Diffusion Measurement • Sunscreen Persistence Measurement

  15. Why OTTER ? • Non-contacting • In-vivo & In-vitro capability • Colour-blind • Surface Sensitive (~10 - 50 µm) • Depth Profiling (surface-referenced) • Small probed diameter (1 mm, down to ~20 µm) • Spectral Selectivity (excitation & emission) • Arbitrary sample (no preparation required) • Quick (~30 sec/point) • Imaging Capability (slow)

  16. OTTER vs Confocal Raman Contact artefacts affect ~5µm of SC Not colour-blind Interference from fluorescence

  17. Plan 1. OTTER Fundamentals 2. OTTER & SC Hydration 3. AquaFlux Fundamentals 4. AquaFlux Applications

  18. Condenser Chamber Method (Water vapour flux density measurement) Closed-Chamber Shields from ambient air movements. Condenser Removes water vapour. Controls the microclimate. Single RHT Sensor Improves accuracy & sensitivity.

  19. Measurement Head Design • Protects measurements from ambient disturbance • Maintains a consistent microclimate • Protects sensor from contamination by hair etc • Does not distort with contact pressure • Insensitive to heating by skin • Can use purpose-designed measurement caps • Rugged

  20. Water Vapour Distribution Within the Chamber Skin Condenser

  21. Temperature Distribution Within the Chamber Skin Condenser

  22. Chamber Microclimate

  23. AquaFlux & the TEWL Guidelines • The following recommendation remains valid:- • Acclimatisation - you cannot take the bio out of bioengineering! • The following recommendations are not relevant:- • Air movement - no effect • Instrument handling - no effect • Probe heating by skin - no effect • Contact pressure - no effect • Pause between measurements - no need, you can site-hop • Measuring surface orientation - minimal effect with correct probe orientation

  24. Droplet Method of Calibration Simple procedure - just add water Traceable to fundamental measures through research with NPL Calibration brings Tewameter & AquaFlux measurements closer together

  25. Plan 1. OTTER Fundamentals 2. OTTER & SC Hydration 3. AquaFlux Fundamentals 4. AquaFlux Applications

  26. Example 1: AquaFlux vs DermaLab DermaLab Signals [1] AquaFlux Signals Measurement speed is comparable, but the fluctuations are much lower in condenser-chamber signals. [1] GL Grove, MJ Grove C Zerweck & E Pierce: Computerized Evaporimetry using the DermaLab TEWL Probe. Skin Res. Technol. 5, 9-13, 1999.

  27. Example 2: Repeatability

  28. Example 3a: Occlusion Recovery Skin Surface Water Loss Final TEWL = 9.3 ± 0.2 g m-2 h-1 Occlusion effectiveness = 17.0 ± 1.6 %

  29. Example 3b: Occlusion Recovery

  30. Example 4: DermarollerTM DermarollerTM on Volar Forearm Cylinder diameter = 20mm Cylinder length = 20mm No. of microneedles = 192 Microneedle length = 130µm Microneedle tip diameter = 1-5µm Hole depth in SC ~ 130µm Hole diameter in SC ~ 70µm Hole density ~ 250/cm2

  31. Example 5: In-vivo Fingernails

  32. Example 6a: In-vitro Nail Transpiration

  33. Example 6b: In-vitro Nail Transpiration

  34. Example 7: Membrane Resistance

  35. Example 8: OTTER - TEWL Correlation

  36. Example 9: Hair Desorption Hair samples pre-conditioned in ambient air. Also SC & Nail Plates

  37. Example 10: Nail Desorption Ambient T ~25 C Ambient RH ~32 % Q1/W1 ~31 % Q2/W2 ~66%

  38. Example 11: Cultured Skin

  39. Why the AquaFlux ? • Easy to use - unfettered by Guideline grief ! • Highest repeatability through consistent microclimate • Klingon sensor - tough & protected • Highest sensitivity • Highest flux capability • Reliable calibration • Versatile - transpiration, desorption, in-vivo, in-vitro, etc.

  40. Acknowledgement - The Team

More Related