Medico-surgical devices
An embryo replacement catheter has a flexible extruded shaft of a transparent polyurethane with a bore extending along its length. Gas bubbles of a diameter in the range 5μ to 10μ are incorporated into the thickness of the wall of the shaft by adding gas during extrusion. The bubbles are selected to increase the visibility of the catheter under ultrasound imaging whilst still enabling material flowing along the catheter to be seen.
1. A medico-surgical device of a plastics material, wherein said plastics material has a thickness, wherein said material includes gas bubbles through a major part of the thickness of said material in at least a part of the device, said gas bubbles in said material increasing the visibility of the device under ultrasound imaging, said gas bubbles being regions of gas bounded by the plastics material of the device forming an interface between the gas and the plastics material, wherein said region is a strip extending along the length of the device.
2. A method of making a medico-surgical device comprising the steps of: extruding a plastics material to form a wall having a thickness; and incorporating a gas into said wall during extrusion such as to form gas bubbles through a major part of the thickness of said wall sufficient to increase the visibility of said device under ultrasound observation, said gas bubbles being regions of gas bounded by the plastics material of the device forming an interface between the gas and the plastics material.
3. A method of making a medico-surgical device comprising forming a wall of a plastics material containing hollow microspheres such as to form gas bubbles through a major part of a thickness of the wall sufficient to increase the visibility of said device under ultrasound observation, said gas bubbles being regions of gas bounded by the plastics material of the device forming an interface between the gas and the plastics material.