MaRVis Technologies GmbH
MRI SAFE AND VISIBLE MEDICAL DEVICES
The presence of both the magnetic and RF fields used in the MR imaging process places several constraints on any equipment to be used in MRI. Amongst other factors this includes:
- the device must be non-ferromagnetic so that it is not attracted by the magnetic field
- the device must not be electrically conductive
- the device should not be subject to significant heating due to the applied RF field
- the device should not create imaging artifacts that obscure or distort the image of the target.
MaRVis´ integrated platform technology for the first time enables the necessary combination of high axial stiffness, torsion capability, general stability, flexibility and tear-resistance as essential material properties, controlled artifact generation for directed visualization and no electric conductivity or heating in MRI.
The basic material („MaRVis rod“, Fig. 1-1) is built from non-metallic filaments (preferably glass fibers) as the core and a non-ferromagnetic polymer (preferably epoxy resin) as an enclosing and agglutinating matrix material which is doped by small metal particles to produce controlled artifacts in MRI. Such a MaRVis rod built from the assembled filaments is sufficiently stiff and can transmit compressive and tractive forces as well as torsional moment. This design allows handling of derived devices according to today's established standards. By doping of the matrix material with small metal particles the MaRVis rods are simply and efficiently visualized in MRI. The particles for doping can be chosen from a variety of metals, sizes, etc. which allows creation of a multitude of different MaRVis rods as a platform of basic materials.
Alternatively a novel coating stably attached to the envelope polymer of the medical device and directly encompassing gadolinium ions may be used to generate ´positive´, clearly distinguishable white contrast to the grey-shaded image of the body tissue which is highly beneficial in certain applications.
A guidewire (Fig. 1-2) is constructed by enclosing and/or agglutinating several MaRVis rods by another non-ferromagnetic matrix material (a polymer). Catheters (Fig. 1-3) are built from several rods which are peripherally embedded in a radial distribution in its (polymer) wall. The composite construction ensures high patient safety of the system.
A prototype MRI guidewire comprising newly optimized, highly tear-resistant MaRVis rods exhibit strongly improved stability properties: after complete breakage of the glass fibers in this guidewire it is nevertheless impossible to disrupt it by manual force. This resolves the residual stability risks under extreme conditions inherent to any fiber-based guidewire devoid of a metal core.
MaRVis´ guidewires and catheters as well as other medical devices derived from the proprietary basic materials enable routine application of MRI for interventional procedures instead of using X-ray guidance. In addition, novel medical therapies will be enabled because of first time availability of appropriate medical devices for investigation of MRI guidance-based treatment concepts.
The described platform technology is broadly covered by the patent application families WO 2007/000148 (including US 2010/0063379) and WO 2009/141165 and further unpublished patent applications as well as comprehensive technology, product and process know-how.
