Patent EP-2189120-A1 (EP)
Inventor: DEVIERE JACQUES
IPC: A61B18/00
Filed: 2008-11-19
Abstract: The surgical needle made of a memory shape alloy, comprises a proximal end and a distal end, a body comprising two different stable forms, of which the first stable form (1) has a first range of temperature and the second stable (2) form has a second range of temperature. The first range of temperature is strictly lower than the second range of temperature. The material constituting the needle body comprises a material insulating with the memory, a conducting material or a thermal and/or electric load. The entire body of the needle is adapted to be heated or cooled. The surgical needle made of a memory shape alloy, comprises a proximal end and a distal end, a body comprising two different stable forms, of which the first stable form (1) has a first range of temperature and the second stable (2) form has a second range of temperature. The first range of temperature is strictly lower than the second range of temperature. The material constituting the needle body comprises a material insulating with the memory, a conducting material or a thermal and/or electric load. The entire body of the needle is adapted to be heated or cooled, by applying a heat or cold source and/or a current for obtaining a transformation of first and second stable form. The insulating material comprises polymer matrix and multi-block copolymers comprising two polymers. The first type of block has a decreased softening temperature, and the second type of block has an increased softening temperature. The softening temperature is a glass transition temperature or a fusion temperature. Each type of blocks has two terminal alcohol functions. The multiblocks are obtained as a reaction product comprising diisocyanates. The polymer matrix obtained by the reaction of a first and a second polymer or a second polymer with a diisocyanate in which both the first and second polymers comprise alcohol functions at the chain end. The softening temperature of the first polymer is 40-45[deg] C. The softening temperature of the second polymer is 20[deg] C greater than the first polymer. The first and second polymers form separate phases. The thermal and/or an electrical conductive material produce an electrical connection. The multiblock polymer is composed of alternating statistics of polycaprolactone blocks having a melting temperature of 40-45[deg] C, and a statistic copolymer block polyester and caprolactone-alt-ether having a melting temperature of 60-70[deg] C. The thermal conductive material and/or electrical conductive material is a thermal conductive thread and/or electrical conductive thread, is embedded within the insulating material, where the filler is present at a concentration greater than its percolation threshold, and is present in the form of powder and fiber or sheets sized between 10 mu m to 1 nm. The percolation threshold is the concentration from which the filler forms a continuous conductive network. The conductive filler is carbon black, carbon fiber, carbon nanofibers, carbon nanotubes and/or graphene sheets. The first stable form is rectilinear, and the second stable form is curved shape. The temperature variation induced by the cold source in the needle allows the passage of the second stable form to a second range of temperature to a third stable form to a third temperature range. The third form stable corresponds to the first stable form. The proximal end is in direct contact with the conductor material comprised in the needle. The transition between the first and second stable forms is effectuated to a first transition temperature. The distal end of the needle has a metallic or ceramic insert allowing to assure its sharpening integrity. An independent claim is included for an endoscopic tool to control the temperature of a foreign body or a surgical instrument such as an endoscopic needle.