Self-inflating urinary catheter

Claim 2

A self-inflating urinary catheter of the type which includes a retention balloon and an inflation lumen connected for conducting fluid to inflate the balloon wherein the improvement comprises a squeezable fluid reservoir connected to the inflation lumen, and means to squeeze the reservoir, said means including at least two parts of which one part includes a stretchable diaphragm adjacent the reservoir, said parts being arranged to be moved together with the reservoir between them thereby stretching the diaphragm and pressurizing the fluid, the stressed diaphragm exerting force on the fluid to expel it from the reservoir and through the inflation lumen to inflate the retention balloon.

Claim 3

A self-inflating urinary catheter according to claim 1 in which one of the parts has a window through which at least part of the stressed diaphragm is visible thereby providing an indication of the amount of fluid remaining in the reservoir before its expulsion to inflate the retention balloon.

Claim 4

A self-inflating urinary catheter according to claim 1 which includes a retention lock to hold the parts of the squeezing means together so as to maintain the diaphragm in a stretched and stressed condition against the reservoir.

Claim 5

A self-inflating urinary catheter according to claim 1 in which the said two parts are hinged together to form a framework, at least one of said parts having a window with the diaphragm secured in the window.

Claim 6

A self-inflating urinary catheter according to claim 1 in which the said two parts are arranged to be moved axially toward each other.

Claim 7

A self-inflating urinary catheter according to claim 1 which includes means by which to view the stressed diaphragm as an indication of the degree of expulsion of fluid from the reservoir.

Claim 8

A self-inflating urinary catheter according to claim 1 which includes a restricted passage between the reservoir and the retention balloon thereby providing an elapse of time between the initial stressing of the diaphragm and the completion of expulsion of the fluid from the reservoir into the balloon.

Claim 9

Apparatus for inflating the retention balloon at the distal end of a urinary catheter comprising: a flexible reservoir connected to the proximal end of the catheter and communicating with the inflation lumen of the catheter, the reservoir containing an initially unpressurized inflation fluid; and means for compressing the reservoir to pressurize the inflation fluid in the reservoir and cause the fluid to flow from the reservoir through the inflation lumen to inflate the retention balloon, the means for compressing the reservoir including a substantially rigid frame member and an elastic membrane supported at its periphery by frame member, the frame member and the reservoir being moveable relative to one another so that the membrane presses against the surface of the reservoir causing the membrane to be distorted and stressed so that the membrane applies a compressive force to the reservoir.

Claim 10

Apparatus for inflating the retention balloon at the distal end of a urinary catheter comprising: a flexible reservoir connected to the proximal end of the catheter and communicating with the inflation lumen of the catheter, the reservoir containing an initially unpressurized inflation fluid; and means for compressing the reservoir to pressurize the inflation fluid in the reservoir and cause the fluid to flow from the reservoir through the inflation lumen to inflate the retention balloon, the means for compressing the reservoir including a substantially rigid frame member and an elastic membrane supported at its periphery by frame member, the frame member and the reservoir being moveable relative to one another so that the membrane presses against the surface of the reservoir causing the membrane to be distorted and stressed so that the membrane applies a compressive force to the reservoir.

Claim 11

The apparatus defined in claim 8 wherein the distortion of the membrane is visible to the operator of the catheter as an indication of the amount of inflation fluid remaining in the reservoir.

Claim 12

The apparatus defined in claim 9 wherein the inflation fluid must pass through a restricted passage between the reservoir and the retention balloon so that there is a delay between the time when the inflation fluid in the reservoir is fully pressurized and the time when the retention balloon is fully inflated.

Claim 13

The apparatus defined in claim 8 wherein the means for compressing the reservoir is releasable to remove the pressure on the fluid in the reservoir and allow the fluid in the retention ballon to flow back to the reservoir to deflate the retention balloon.