Method and apparatus for pressure measurement

Abstract

Methods and apparatus for measuring pressure in a patient are provided which may include any number of features. One feature is a pressure measurement system comprising a pressure source, a compliant bladder, a catheter in communication with the pressure source, pressure sensors, and a controller configured to determine a pressure within the compliant bladder. The pressure measurement system can inflate the compliant bladder with gas or air to determine a pressure within a patient. In one embodiment, the pressure measurement system measures pressure within a peritoneal cavity.

1 .- 2 . (canceled) 
     
     
         3 . A method of monitoring a fluid from a patient, comprising:
 detecting when a catheter is connected to a controller;   receiving the fluid through the catheter when the catheter is positioned within a patient body, wherein the fluid is received within a reservoir which is in fluid communication with the catheter;   sensing a volume of the fluid received within the reservoir;   emptying the reservoir automatically when the fluid within the reservoir reaches a predetermined volume; and   determining via the controller a cumulative total volume of the fluid received from the patient body.   
     
     
         4 . The method of  claim 3  wherein the fluid is received within the reservoir which comprises a rigid cassette. 
     
     
         5 . The method of  claim 3  wherein emptying the reservoir comprises actuating a valve to open such that the fluid within the reservoir is removed upon reaching the predetermined volume. 
     
     
         6 . The method of  claim 3  further comprising tracking via the controller a fluid output rate received from the patient body. 
     
     
         7 . The method of  claim 6  further comprising displaying the fluid output rate. 
     
     
         8 . The method of  claim 3  further comprising inflating a pressure sensing membrane disposed on the catheter prior to receiving the fluid through the catheter. 
     
     
         9 . The method of  claim 8  further comprising executing a priming sequence prior to sensing a pressure of the fluid, the priming sequence comprising:
 commanding a pressure source to fill the pressure sensing membrane with a first volume of fluid; and 
 after filling the pressure sensing membrane with the first volume of fluid, commanding the pressure source to remove a second volume of fluid from the pressure sensing membrane. 
 
     
     
         10 . The method of  claim 9  further comprise periodically repeating the priming sequence to ensure accurate pressure measurements. 
     
     
         11 . The method of  claim 10  further comprising identifying drift in a pressure signal. 
     
     
         12 . The method of  claim 8  further comprising measuring a pressure of the pressure sensing membrane with a pressure sensor in communication with the pressure sensing membrane and with the controller to determine a pressure within the patient. 
     
     
         13 . The method of  claim 8  further comprising anchoring the catheter within the patient via a retention balloon prior to inflating the pressure sensing membrane. 
     
     
         14 . The method of  claim 8  further comprising removing a volume of gas from the pressure sensing membrane. 
     
     
         15 . The method of  claim 14  wherein removing the volume of gas further comprises opening the pressure sensing membrane to a lower pressure for a period of time to remove the gas from the pressure sensing membrane. 
     
     
         16 . The method of  claim 8  wherein inflating further comprises inserting the catheter into a peritoneal cavity of the patient. 
     
     
         17 . The method of  claim 8  wherein inflating further comprises inserting the catheter into a stomach of the patient. 
     
     
         18 . The method of  claim 8  wherein inflating further comprises inserting the catheter into a urinary tract of the patient. 
     
     
         19 . The method of  claim 3  wherein the catheter is configured to wirelessly communicate with the controller. 
     
     
         20 . The method of  claim 3  wherein the catheter is configured to convey identification information about the catheter to the controller. 
     
     
         21 . The method of  claim 3  wherein the catheter is configured to provide tactile feedback when connected to the controller. 
     
     
         22 . A catheter system, comprising:
 a catheter configured for anchoring within a patient body;   a reservoir which is in fluid communication with the catheter;   a sensor in communication with the reservoir and with the controller, wherein the sensor is configured to detect a volume of the fluid within the reservoir;   a controller configured to detect when the catheter is connected to the controller and which is further configured to actuate the reservoir to empty automatically when the fluid within the reservoir reaches a predetermined volume.   
     
     
         23 . The system of  claim 22  wherein the reservoir comprises a rigid cassette. 
     
     
         24 . The system of  claim 22  further comprising a valve in communication with the controller, wherein the controller is configured to actuate the valve to open to empty the reservoir. 
     
     
         25 . The system of  claim 22  wherein the controller is further configured to track a fluid output rate received from the patient body. 
     
     
         26 . The system of  claim 25  wherein the controller is further configured to display the fluid output rate. 
     
     
         27 . The system of  claim 22  further comprising a pressure sensing membrane disposed on the catheter for detecting a fluid pressure. 
     
     
         28 . The system of  claim 27  further comprising a pressure sensor coupled to the pressure sensing membrane, wherein the pressure sensor is configured to receive a pressure signal from the pressure sensing membrane. 
     
     
         29 . The system of  claim 27  further comprising a pressure source coupled to the pressure sensing membrane. 
     
     
         30 . The system of  claim 29  wherein the controller is configured to control the pressure source to control a flow of fluid from the pressure sensing membrane. 
     
     
         31 . The system of  claim 27  wherein the pressure sensing membrane comprises a pressure sensing balloon. 
     
     
         32 . The system of  claim 27  wherein the controller is programmed with instructions to execute a priming sequence, the instructions comprising:
 commanding a pressure source to fill the pressure sensing membrane with a first volume of fluid; and 
 after filling the pressure sensing membrane with the first volume of fluid, commanding the pressure source to remove a second volume of fluid from the pressure sensing membrane. 
 
     
     
         33 . The system of  claim 32  wherein the instructions further comprise periodically repeating the priming sequence to ensure accurate pressure measurements. 
     
     
         34 . The system of  claim 32  wherein the controller is programmed with instructions to execute a leak test sequence, the instructions comprising identifying drift in the pressure signal. 
     
     
         35 . The system of  claim 22  wherein the controller is further configured to collect identifying information from the catheter. 
     
     
         36 . The system of  claim 22  wherein the catheter is configured to wirelessly communicate with the controller. 
     
     
         37 . The system of  claim 22  wherein the catheter is configured to provide tactile feedback when connected to the controller.