Balloon catheter leak detection method and apparatus

Abstract

An intra-aortic balloon pump system having a leak detector comprising a processor, a pressure sensor, and optionally a temperature sensor. Gas leaks from the intra-aortic balloon pump system are detected by comparing shuttle gas pressure readings, taken just prior to IAB inflation, with similar thermodynamic histories, i.e. similar equilibrium times.

What is claimed is:  
     
         1 . A leak detector device for a pressurized cardiac assist device for use on a patient comprising a processor and a pressure sensor communicating with said processor for sensing the pressure of a gas in said pressurized cardiac assist device, said pressurized cardiac assist device comprising one or more chambers, said one or more chambers being filled and evacuated of the gas by a pump, during therapy said one or more chambers being maintained in an evacuated state during at least a portion of the patient's heartbeat and being maintained in a filled state during at least a portion of a patient's heartbeat, the processor comparing pressure measurements taken by the pressure sensor from different fill/evacuation cycles having similar evacuation interval durations and indicating a pressure loss or gain if the pressure measurements vary beyond a predetermined level.  
     
     
         2 . The device as claimed in  claim 2  wherein the processor compares pressure measurements taken by the pressure sensor from fill/evacuation cycles of the one or more chambers having similar fill and evacuation interval durations.  
     
     
         3 . A leak detector device for a pressurized cardiac assist device for use on a patient comprising a processor and a pressure sensor communicating with said processor for sensing the pressure of a gas in said pressurized cardiac assist device, said pressurized cardiac assist device comprising one or more chambers, said one or more chambers being filled and evacuated of the gas by a pump, during therapy said one or more chambers being maintained in an evacuated state during at least a portion of the patient's heartbeat and being maintained in a filled state during at least a portion of a patient's heartbeat, the processor comparing pressure measurements taken by the pressure sensor from different fill/evacuation cycles having similar fill interval durations and indicating a pressure loss or gain if the pressure measurements vary beyond a predetermined level.  
     
     
         4 . The leak detector device as claimed in  claim 1  wherein the cardiac assist device comprises a balloon catheter, said balloon catheter comprising a tube connected on one end to a balloon membrane, and wherein the chamber comprises a volume defined by the balloon membrane and the pump being connected to the tube.  
     
     
         5 . The leak detector device as claimed in  claim 3  wherein the cardiac assist device comprises a balloon catheter, said balloon catheter comprising a tube connected on one end to a balloon membrane, and wherein the chamber comprises a volume defined by the balloon membrane and the pump being connected to the tube.  
     
     
         6 . The leak detector device as claimed in  claim 1  wherein the cardiac assist device comprises a balloon catheter, said balloon catheter comprising a tube connected on one end to a balloon membrane, and wherein the chamber comprises a volume defined by the balloon membrane and the pump being connected to the tube, the processor measures the gas pressure in the balloon catheter at the same point in a plurality of fill/evacuation cycles of the balloon.  
     
     
         7 . The leak detector device as claimed in  claim 3  wherein the cardiac assist device comprises a balloon catheter, said balloon catheter comprising a tube connected on one end to a balloon membrane, and wherein the chamber comprises a volume defined by the balloon membrane and the pump being connected to the tube, the processor measures the gas pressure in the balloon catheter at the same point in a plurality of fill/evacuation cycles of the balloon.  
     
     
         8 . The leak detector device as claimed in  claim 1  wherein the cardiac assist device comprises a balloon catheter, said balloon catheter comprising a tube connected on one end to a balloon membrane, and wherein the chamber comprises a volume defined by the balloon membrane and the pump being connected to the tube, the processor compares pressure measurements taken just prior to the fill of the balloon.  
     
     
         9 . The leak detector device as claimed in  claim 3  wherein the cardiac assist device comprises a balloon catheter, said balloon catheter comprising a tube connected on one end to a balloon membrane, and wherein the chamber comprises a volume defined by the balloon membrane and the pump being connected to the tube, the processor compares pressure measurements taken just prior to the fill of the balloon.  
     
     
         10 . The leak detector device as claimed in  claim 1  wherein the cardiac assist device comprises a balloon catheter and a memory unit connected to the processor for storing pressure measurements, said balloon catheter comprising a tube connected on one end to a balloon membrane, and wherein the chamber comprises a volume defined by the balloon membrane and the pump being connected to the tube.  
     
     
         11 . The leak detector device as claimed in  claim 3  wherein the cardiac assist device comprises a balloon catheter and a memory unit connected to the processor for storing pressure measurements, said balloon catheter comprising a tube connected on one end to a balloon membrane, and wherein the chamber comprises a volume defined by the balloon membrane and the pump being connected to the tube.