MRT-compatible valve prosthesis for use in the human or animal body for replacement of an organ valve or a vessel valve
The invention relates to a biological or artificial valve prosthesis ( 4, 5 ) for use in the human or animal body for replacement of an organ valve or a vessel valve, in particular a cardiac valve prosthesis or venous valve prosthesis, with a stent ( 8 ) or without a stent, with a supporting valve framework, with at least one valve ( 7 ) and with at least one conductor loop ( 2 ) that forms the inductance of an electrical resonance circuit. In order to provide a simple and inexpensive valve prosthesis that can be viewed in the MR imaging technique and is also easy to implant, the invention proposes that the at least one conductor loop ( 2 ) forms the valve framework and/or the valve ( 7 ) or supporting areas of the valve framework and/or supporting areas of the valve ( 7 ).
1. A biological or artificial valve prosthesis for use in a human or animal body for replacement of an organ valve or a vessel valve, particularly a cardiac valve prosthesis or a venous valve prosthesis, with a supporting valve framework, with at least one valve and with at least one conductor loop which forms the inductance of an electrical resonance circuit,
wherein at least one conductor loop forms the valve framework and/or the valve or supporting areas of the valve framework and/or supporting areas of the valve,
wherein the valve framework and the valve are fixed by the conductor loop in a self-deployable or mechanically expandable stent, so that, in the case of compression and subsequent deployment, both the valve framework and the valve and also the conductor loop return to the desired form, position and geometry, and the conductor loop simultaneously serves to fasten the valve on the stent, wherein the resonant circuit has a resonant frequency, which corresponds to the frequency of an external magnetic field of an MR tomograph.
2. The valve prosthesis as set forth in claim 1 , wherein at least areas of the conductor loop are drawn out of the stent for anchoring in the surrounding tissue.
3. The valve prosthesis as set forth in claim 1 , wherein the resonant circuit has a resonant frequency, particularly in the range of 8 to 400 MHz.
4. The valve prosthesis as set forth in claim 1 , wherein the conductor loop is cut form a wire or a tube from sheet metal and produced from a material with a low magnetic susceptibility and/or a good electric conductivity.
5. The valve prosthesis as set forth in claim 1 , wherein the conductor loop has an electrically conductive or electrically nonconductive conductor support which is coated by a conductive material, particularly gold, platinum, tantalum, silver or copper and/or conductive alloys.
6. The valve prosthesis as set forth in claim 1 , wherein the conductor loop is implemented through a coating of the valve prosthesis with an electrically conductive material and that the electrically conductive or non-conductive material of the valve prosthesis is vapor-deposited or sputtered with the electrically conductive material.
7. The valve prosthesis as set forth in claim 1 , wherein with polymers, ceramic, nickel titanium and titanium as a material of the conductor support, a base layer is applied onto the conductor loop in order to improve the adhesion of a coating.
8. The valve prosthesis as set forth in claim 1 , wherein the conductor loop is coated with plastic such as teflon, polyester, polyurethane, parylene or similar polymers, and/or ceramic and that, preferably, the coating has a thickness of at least one nanometer.
9. The valve prosthesis as set forth in claim 1 , wherein an additional capacitance of the resonance circuit is implemented by a capacitor.
10. The valve prosthesis as set forth in claim 1 , wherein the dielectric layer has the additional task of attaching or fixing another coil belonging to the resonant circuit and/or at least one capacitance on or in the framework of the prosthesis.