Medico-surgical devices
An embryo-transfer catheter has an extruded shaft with a gas-filled lumen that extends helically along the catheter to provide an ultrasound marker. The catheter has a side opening close to a closed rounded patient end. The catheter could be completely transparent to x-rays or the plastics from which it is formed could incorporate an x-ray opaque filler, such as barium sulphate.
1. A catheter for use under external ultrasound observation, the catheter comprising: an open hub at one end by which fluid can be supplied to or from the catheter, said fluid being either a gas or a liquid, a tubular body extending from said hub and opening at an opposite end of said catheter, said tubular body having a wall of a material that provides a relatively low ultrasound reflection during use and through which a fluid passes; and a marker providing a relatively high ultrasound reflection during use, wherein said marker extends helically along said tubular body and along its length so that an interruption in said fluid is readily ascertained by the difference in acoustic properties between said interruption and said fluid, and wherein said marker is extruded within the thickness of the wall as at least one closed gas-filled lumen, such that ultrasound energy is reflected externally of the body by the at least one closed gas-filled lumen.
2. A catheter device according to claim 1 , wherein said marker is continuous.
3. A catheter according to claim 1 , wherein said body has a closed rounded patient end and a side opening close to the patient end.
4. A catheter according to claim 1 , wherein said interruption comprises an embryo.
5. A catheter according to claim 1 , wherein said interruption in said fluid in said tubular body obscures said marker on the far side of said tubular body.
6. A catheter according to claim 1 , wherein said interruption comprises a gas bubble.
7. A catheter according to claim 1 , wherein said marker is configured to be equally visible regardless of the angular orientation of said tubular body relative to a scanner.
8. A catheter according to claim 1 , wherein said marker extends intermittently along the entire length of said tubular body.
9. An embryo-transfer catheter for use under external ultrasound observation, the catheter comprising: a hollow tubular body of a plastics material that provides a relatively low ultrasound reflection during use, said body having a closed, rounded patient end and a side opening close to said patient end; and a marker that provides a relatively high ultrasound reflection during use, said marker extending on an elongate path along and around said tubular body within the thickness of the wall of said body, wherein said marker is an extruded at least one closed gas-filled lumen within the wall of the body extending helically along and around said body, such that ultrasound energy is reflected externally of said body by the at least one closed gas-filled lumen and such that an embryo within said catheter is visible.
10. An embryo transfer catheter according to claim 9 , wherein said marker extends intermittently along the entire length of said tubular body.
11. An embryo transfer catheter according to claim 9 , wherein said marker is continuous.