Safe urinary catheter and manufacturing method

1. A urinary catheter for draining urine from a bladder of a patient, the urinary catheter comprising:

an elongate, flexible, tubular catheter shaft having a proximal end and a distal end and consisting of silicone;

a connector coupled with the proximal end of the catheter shaft, wherein the connector comprises:

a first arm ending in a fluid outlet configured to allow urine to flow out of the urinary catheter; and

a second arm comprising an aperture and ending in an inflation inlet used for introducing inflation fluid into the urinary catheter;

a primary lumen extending through the catheter shaft from a fluid inlet at or near the distal end of the catheter shaft to the fluid outlet on the first arm of the connector;

an inflation lumen extending through the catheter shaft from a distal filling hole in the catheter shaft to the inflation inlet on the second arm of the connector;

a retention balloon mounted to the catheter shaft proximal to the fluid inlet and over the distal filling hole, wherein the retention balloon is made of silicone and comprises a preformed balloon shape when not inflated, a first wall thickness, and a first durometer; and

a pilot balloon consisting of a tubular member mounted on the second arm of the connector over the aperture in a location that is outside the patient during use of the urinary catheter, wherein the pilot balloon is made of silicone and comprises a tubular shape when not inflated, a second wall thickness that is greater than the first wall thickness, and a second durometer that is greater than the first durometer,

wherein the retention balloon is configured to inflate at a first inflation pressure, and the pilot balloon is configured to inflate at a second inflation pressure that is higher than the first inflation pressure and lower than a predetermined pressure threshold,

wherein a difference between the first inflation pressure and the second inflation pressure is configured to allow the pilot balloon to deflate in 3-10 seconds if the first inflation pressure is below the predetermined threshold after the retention balloon is inflated, and

wherein the pilot balloon will not deflate if the retention balloon pressure is above the predetermined threshold after filling.

2. The urinary catheter of claim 1 , wherein the aperture in the second arm of the connector is selected from the group consisting of one hole, multiple holes, a slit, and a gap between two portions of the second arm.

3. The urinary catheter of claim 1 , wherein a cross-sectional area of the aperture in the second arm of the connector is less than a cross-sectional area of the distal filling hole.

4. The urinary catheter of claim 1 , further comprising a check valve attached to a proximal end of the second arm, wherein the inflation inlet comprises a proximal end of the check valve.

5. The urinary catheter of claim 1 , wherein the retention balloon has a first length, and the pilot balloon has a second length that is different than the first length.

6. The urinary catheter of claim 1 , wherein the retention balloon has a first radius, and the pilot balloon has a second radius that is less than the first radius.

7. The urinary catheter of claim 1 , wherein the retention balloon has a first inflated shape, and the pilot balloon has a second inflated shape that is different than the first inflated shape.

8. The urinary catheter of claim 1 , further comprising a radiopaque strip extending through at least a portion of the catheter shaft.

9. A method of manufacturing a urinary catheter for draining urine from a bladder of a patient, the method comprising:

providing an elongate, flexible, tubular catheter shaft having a proximal end and a distal end and consisting of silicone and further comprising:

a primary lumen extending through the catheter shaft from a fluid inlet at or near the distal end of the catheter shaft to the proximal end of the catheter shaft; and

an inflation lumen extending through the catheter shaft from a distal filling hole near the distal end of the catheter shaft to the proximal end of the catheter shaft;

attaching a connector with the proximal end of the catheter shaft, wherein the connector comprises:

a first arm in fluid communication with the primary lumen and ending in a fluid outlet configured to allow urine to flow out of the urinary catheter; and

a second arm comprising an aperture in fluid communication with the inflation lumen and ending in an inflation inlet used for introducing inflation fluid into the urinary catheter;

mounting a retention balloon on the catheter shaft over the distal filling hole and proximal to the fluid inlet, wherein the retention balloon is made of silicone, has a preformed balloon shape when not inflated, and has a first wall thickness and a first durometer; and

mounting a tubular pilot balloon consisting of a tubular member on the second arm of the connector over the aperture in the second arm in a location that is outside the patient during use of the urinary catheter, wherein the pilot balloon is made of silicone and comprises a tubular shape when not inflated, a second wall thickness that is greater than the first wall thickness, and a second durometer that is greater than the first durometer,

wherein the retention balloon is configured to inflate at a first inflation pressure, and the pilot balloon is configured to inflate at a second inflation pressure that is higher than the first inflation pressure and lower than a predetermined pressure threshold,

wherein a difference between the first inflation pressure and the second inflation pressure is configured to allow the pilot balloon to deflate in 3-10 seconds if the first inflation pressure is below the predetermined threshold after the retention balloon is inflated, and

wherein the pilot balloon will not deflate if the retention balloon pressure is above the predetermined threshold after filling.

10. The method of claim 9 , further comprising forming the aperture in the second arm.

11. The method of claim 10 , wherein forming the aperture comprises forming at least one of a hole, a slit or a cut in the second arm.

12. The method of claim 9 , wherein a cross-sectional area of the aperture in the second arm is less than a cross-sectional area of the distal filling hole.

13. The method of claim 9 , further comprising:

forming the tubular pilot balloon to have the tubular shape; and

forming the retention balloon to have the preformed balloon shape,

wherein a higher pressure is required to begin inflating the tubular pilot balloon than the retention balloon.

14. The method claim 9 , further comprising:

forming the retention balloon to have the first balloon wall thickness; and

forming the pilot balloon to have the second balloon wall thickness.

15. The method of claim 9 , further comprising:

forming the retention balloon to have a first length; and

forming the pilot balloon to have a second length that is different than the first length.

16. The method of claim 9 , further comprising:

forming the retention balloon to have a first inflated shape; and

forming the pilot balloon to have a second inflated shape that is different than the first inflated shape.