Totally self-contained, digitally controlled, disposable syringe inflation system, and method for monitoring, displaying and recording balloon catheter inflation data

A system for generating a series of discrete balloon catheter inflations and for automatically displaying and recording inflation data corresponding to each said discrete inflation, comprising:

• (a) a control syringe connected to a balloon of said balloon catheter through tubing, said syringe comprising a barrel and a plunger selectively operable to first apply and then remove positive fluid pressures to said balloon through said tubing by sliding the plunger within the barrel;
• (b) a piezoresistive semiconductor transducer connected in fluid communication with said fluid pressures applied to said balloon catheter such that said transducer senses fluid pressures applied to said balloon and generates an electrical signal proportional to the sensed fluid pressure;
• and
• (c) a controller mounted on said syringe barrel and electrically connected to said transducer, said controller comprising:
• (i) means for amplifying said signal output by said transducer;
• (ii) means for converting said amplified signal from an analog to a digital form;
• (iii) digital processor means for processing said digital form of said signal so as to electronically monitor, display and record inflation pressure applied to said balloon and the duration of inflation by performing the steps of:
• (A) deriving data from said digital signals which represents a numerical value of the magnitude of said applied pressure;
• (B) deriving data from said digital signals which represent a numerical value of the duration of said inflation pressure;
• (C) electronically storing all said derived data;
• and
• (D) displaying said numerical values in a visually perceptible manner to a system user;
• (iv) data memory means for storing the digital data derived by said digital processor means;
• (v) program memory means for storing machine-readable instructions utilized by said digital processor means to perform said steps;
• and
• (vi) display means for visually identifying said numerical value of the magnitude of said applied pressure together with a corresponding numerical value of said duration of said inflation pressure.

In a system for generating a series of discrete balloon catheter inflations and for automatically recording inflation data derived from an electrical signal corresponding to each said discrete inflation, an improved control syringe comprising:

• a barrel comprised of plastic material and connected through tubing to a balloon of said balloon catheter;
• a plunger comprised of plastic material and slidably mounted within said barrel and operable to selectively apply and then release fluid pressure on said balloon by movement of the plunger within said barrel;
• a piezoresistive semiconductor transducer mounted on said syringe barrel and in fluid communication with the interior of said syringe barrel through a hole formed in a side of said syringe barrel such that changes in fluid pressure applied to said balloon by sliding said plunger are sensed by said transducer, which in turn generates an electrical signal proportional to the sensed positive fluid pressure;
• means for preventing said syringe plunger from ever occluding said hole;
• and
• whereby toxic elements cannot be introduced into said fluid from said transducer.

In a system comprising an inflatable balloon member connected through tubing to a syringe barrel and wherein a plunger slidably mounted within said barrel is moveable to selectively apply and then release fluid pressures exerted on said balloon member so as to selectively inflate said balloon member one or more times, a method of monitoring, displaying and automatically recording inflation data comprising the steps of:

• electronically sensing whether a transducer is connected to said system and if so, electronically measuring any offset signal at zero pressure;
• electronically comparing the measured offset signal with a previously electronically stored value of an offset signal, and if the measured offset signal is within a selected range of the stored offset signal, using the measured offset signal in subsequent determinations of applied pressure, and if the measured offset signal is not within said selected range, using the previously stored value of the offset signal in subsequent determinations of applied pressure;
• selectively increasing fluid pressure applied to the balloon member by pushing said plunger into said syringe barrel;
• sensing the fluid pressure applied by said syringe and outputting an electrical signal proportional to the sensed fluid pressure;
• amplifying said electrical output signal;
• converting said amplified signal from an analog to a digital form;
• digitally processing the digital form of said signal so as to derive therefrom digital data from which said magnitude of said applied fluid pressures and the length of time said fluid pressures are applied to said balloon member may be output in numeric form;
• storing the digital data;
• selectively retrieving and outputting said stored digital data in a form which can be visually perceived and read by an operator of the system;
• and
• releasing the fluid pressure applied to the balloon member by pulling said plunger toward the rear of the syringe barrel.

In a system comprising a balloon catheter connected through tubing to a syringe barrel and wherein by movement of a plunger through the barrel fluid pressure applied to a balloon of the balloon catheter may be selectively increased or decreased, a method of electronically monitoring, displaying and recording the applied fluid pressure each time the balloon is inflated, the method comprising the steps of:

• electronically sensing whether a transducer is connected to said system and if so, electronically measuring any offset signal at zero pressure;
• electronically comparing the measured offset signal with a previously electronically stored value of an offset signal, and if the measured offset signal is within a selected range of the stored offset signal, using the measured offset signal in subsequent determinations of applied pressure, and if the measured offset signal is not within said selected range, using the previously stored value of the offset signal in subsequent determinations of applied pressure;
• inflating the balloon a first time by pushing the plunger into the syringe barrel so as to apply a positive inflation pressure to the balloon;
• sensing any applied fluid pressure using a piezoresistive semiconductor transducer placed in fluid communication with the applied pressure, and generating at said transducer an electrical signal proportional in magnitude and duration to said applied pressure;
• converting said electrical signal to a series of corresponding digital signals and inputting said digital signals to a digital processor;
• processing the digital signals using said digital processor to carry out a programmed method comprising the steps of:
• deriving data from said digital signals which represents a numerical value of the magnitude of said applied pressure;
• deriving data from said digital signals which represent a numerical value of the duration of said positive inflation pressure;
• electronically storing all said derived data;
• and
• displaying said numerical values in a visually perceptible manner to a system user;
• deflating the balloon by withdrawing the syringe plunger so as to remove the positive fluid pressure applied to the balloon catheter;
• and
• repeating each of the above-recited steps for a second inflation of the balloon.

In a system comprising a balloon catheter connected through tubing to a syringe barrel and wherein by movement of a plunger through the barrel fluid pressure applied to a balloon of the balloon catheter may be selectively increased or decreased, a method of electronically monitoring, displaying and recording the applied fluid pressure each time the balloon is inflated, the method comprising the steps of:

• inflating the balloon a first time by pushing the plunger into the syringe barrel so as to apply a positive inflation pressure to the balloon;
• sensing any applied fluid pressure using a piezoresistive semiconductor transducer placed in fluid communication with the applied pressure, and generating at said transducer an electrical signal proportional in magnitude and duration to said applied pressure;
• converting said electrical signal to a series of corresponding digital signals and inputting said digital signals to a digital processor;
• processing the digital signals using said digital processor to carry out a programmed method comprising the steps of:
• deriving data from said digital signals which represents a numerical value of the magnitude of said applied pressure;
• deriving data from said digital signals which represent a numerical value of the duration of said positive inflation pressure;
• electronically storing all said derived data;
• connecting a digital display means and a backlighting means to a battery source;
• and
• disconnecting at least one of said digital display means and said backlighting means from said battery source if a zero pressure is sensed during a selected time interval;
• deflating the balloon by withdrawing the syringe plunger so as to remove the positive fluid pressure applied to the balloon catheter;
• and
• repeating each of the above-recited steps for a second inflation of the balloon.

In a system comprising an inflatable balloon member connected through tubing to a syringe barrel and wherein a plunger slidably mounted within said barrel is moveable to selectively apply and then release fluid pressures exerted on said balloon member so as to selectively inflate said balloon member one or more times, a method of monitoring, displaying and automatically recording inflation data comprising the steps of:

• electronically sensing whether a transducer is connected to said system and if so, electronically measuring any offset signal at zero pressure;
• electronically comparing the measured offset signal with one of several previously stored values corresponding to different offset signals, whereby the measured offset signal is determined to be within one of several previously selected ranges;
• outputting a visual display identifying a selected range and a corresponding type of syringe that is in use;
• using selected parameters previously electronically stored for the type of syringe in use in subsequent determinations of applied pressure;
• selectively increasing fluid pressure applied to the balloon member by pushing said plunger into said syringe barrel;
• sensing the fluid pressure applied by said syringe and outputting an electrical signal proportional to the sensed fluid pressure;
• amplifying said electrical output signal;
• converting said amplified signal from an analog to a digital form;
• digitally processing the digital form of said signal so as to derive therefrom digital data from which said magnitude of said applied fluid pressures and the length of time said fluid pressures are applied to said balloon member may be output in numeric form;
• storing the digital data;
• selectively retrieving and outputting said stored digital data in a form which can be visually perceived and read by an operator of the system;
• and
• releasing the fluid pressure applied to the balloon member by pulling said plunger toward the rear of the syringe barrel.