Surface Analysis - Surface Characterisation Techniques for the Medical Device Industry by CERAM

Topics Covered

Introduction
Surface Analysis of Implanted Devices
Surface Characterisation Services Offered by CERAM
Stains and Contamination on Medical Devices
Implementing Cleanliness Validation
Characterisation of Drug Eluting Stent (DES) Coatings
Defect Analysis on Corroded Medical Devices
Chemical Imaging Techniques for Medical Fabric

Tag Links : Surface analysis | Materials analysis | Medical Devices | X-ray Photoelectron Spectroscopy | ToFSIMS

Introduction

CERAM is a global expert in materials analysis, research and quality testing, providing customised solutions and consultancy that help clients to measurably improve performance and profitability through safer, regulatory-compliant and better-engineered products. Setting new standards in materials testing, CERAM works as an extension of customers' teams, applying its expertise and capabilities to a wide range of sectors

CSMA has been working in partnership with R&D and production personnel in companies around the world for over 25 years. Using our expertise, experience and a comprehensive suite of advanced instrumentation we have been able to solve problems and create competitive advantage for our clients in the medical device industry.

Surface Analysis of Implanted Devices

The first encounter an implanted device has within the body involves its surface. Whatever mechanical or bulk-related attributes an implant has, it is almost certainly its surface properties that trigger the body’s initial, acute response. Utilising a range of techniques such as:

Surface Characterisation Services Offered by CERAM

CSMA can investigate issues relating to surface analysis such as:

Stains
Contamination including fibres and particulates
Cleanliness Validation
Packaging problems-delaminations and disbondments
Migration and Leaching
Coating Characterisation

Stains and Contamination on Medical Devices

When stains and contaminants are found on medical devices production stops. A recent case involved an orthopaedic implant with a white mark. Using a multi-technique approach it was discovered that the mark was potassium and calcium rich in comparison with unmarked areas. Further physical investigation showed that the mark was due to a polishing failure. Results were reported within 8 hours, corrective action was taken and production re-started.

Implementing Cleanliness Validation

CSMA's ‘Validata’ service monitors cleanliness by setting a baseline with the customer and then analysing products at set intervals and relating them to the baseline. This system highlights problems before they become major production stopping issues. A medical device company who implemented ‘Validata’, analysing one product a month, reported that problems had been cut significantly.

Characterisation of Drug Eluting Stent (DES) Coatings

As medical device coatings are becoming increasingly complex the need to characterise the coating is becoming ever more important. One example of this is the drug eluting stent (DES). DES coatings are complex multi-layer systems. The need to understand not only the surface chemistry but also the topography and the layer composition is vitally important in the research and development of next generation products. Utilising high-resolution depth profiling layer systems can be characterised whilst sensitive ToFSIMS analysis provides detailed molecular composition. 3DP can provide topographical information such as surface roughness quantification.

Defect Analysis on Corroded Medical Devices

Defects can be a result of poor manufacture or corrosion. In order to eliminate defects it is important to characterise them. The defect pictured was recently analysed by SEM/EDX. From the high resolution image it can be seen that the defect is a corrosion pit. Chemical analysis showed an increase in phosphorous in the defect area. It was concluded that the phosphorous had not been removed during the cleaning of the device and that the residue had led to corrosion.

Chemical Imaging Techniques for Medical Fabric

Whilst knowing what chemistry is on a surface is important in certain cases knowing where the chemistry is on the surface is more important. Chemical imaging techniques such as ToFSIMS and XPS can be used to image elements, oxidation states and molecular information. XPS imaging of a medical fabric highlighted where a protein adhesion inhibiting coating was located. As can be seen, the coating (green) is not uniform.