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The U.S. Senate has introduced a bill that allows the FDA to require medical device companies to collect and track data on the clinical performance of their marketed devices, such as hip and knee replacements. This action is in part due to the on-going reported issues of metal-on-metal hip implants failing due to metal ion sensitivity, which some studies have shown lead to the formation of pseudo-tumors. Advocates for this data collection suggest that the information will be useful for the on-going 510(k) regulatory approval process for new devices that have similar characteristics to already marketed devices, for-going the need for clinical studies necessary in a full PMA process.

Cambridge Polymer Group is now partnered with Pulse Anatomy to produce custom anatomy models made from our patented materials for use in clinical device development and professional education. Pulse replicates the anatomy using digital data as a starting point for the process of printing of rapid prototyped parts, creating molds and producing castings. Pulse's team includes digital designers, mechanical and electrical engineers, artists, sculptors, model makers and machinists. The process of developing a model with the Pulse and Cambridge Polymer Group team is a collaborative effort with our clients to ensure the final product meets the clients criteria. Please visit Pulse Anatomy for more information on model choices, or contact CPG.

Our tissue models can be fabricated from silicone, polyurethane, or tissue-mimicking hydrogels using our patented formulations.

PEEK finds itself increasingly being used in medical device applications due to its strength, biocompatibility, resistance to radiation and degradation, and ease of processing. CPG has been providing testing services on PEEK for our clients for several years, including crystallinity assessment by DSC and FTIR, mechanical properties, surface morphology characterization, and rheological characterization. CPG now offers gel permeation chromatography assessment of molecular weight distribution of PEEK.

Cambridge Polymer Group now offers the following testing capabilities:

Variable Pressure/Environmental Scanning Electron Microscopy
Conventional scanning electron microscopy requires high vacuum and samples with a conductive surface. Polymeric materials usually have to be coated with a metal layer (gold, palladium, iridium, carbon), and wet samples must be thoroughly dried. With variable pressure SEM, wet and uncoated samples can be imaged. Cambridge Polymer Group has used this technique to examine the microstructure of hydrogels, as well as salts.

Confocal Raman Spectroscopy
A complementary technique to infrared spectroscopy, Raman spectroscopy can be conducted on wet samples without the interference of water. Raman maps can be constructed, providing compositional information as a function of position on the sample.

Engineers are increasingly turning to so-called smart fluids to solve complex mechanical problems. One specific type of smart fluid is the magnetorheological fluid (MR fluid) which greatly increases its viscosity to the point of becoming a viscoelastic solid when subjected to a magnetic field. Importantly, the yield stress and viscosity of the fluid when in its active state can be controlled very accurately by varying the magnetic field intensity. CPG has recently developed an MR fluid testing apparatus that integrates with a standard shear rheometer made by TA Instruments.

The MR fixture mounted on a TA Instruments AR-G2 shear rheometer

CPG has developed a hardware and software add-on that enables a current commercial shear rheometer to test magnetorheological fluids across temperature and field strengths relevant for a wide range of industries. The MR fixture leverages existing rheometer hardware and uses a parallel plate geometry in a controlled magnetic field over a wide temperature range while monitoring conventional shear viscosity parameters such as stress, strain and viscosity in steady or dynamic shearing modes. The high power magnet of this instrument provides the ability to characterize magnetorheological fluids through the spectrum of magnetic flux ranging from -1 to +1 Tesla, or more and across a broad temperature range.

The MR fixture is sold through TA Instruments. Contact Cambridge Polymer Group for more details.

Schematic diagram of sample shearing zone of MR fixture