System and method for monitoring, displaying and recording balloon catheter condition interval data

• US 5,458,571 A
• Filed: 04/04/1994
• Issued: 10/17/1995
• Est. Priority Date: 03/17/1989
• Status: Expired due to Term

• Current Assignee: Merit Medical Systems, Inc.
• Original Assignee: Merit Medical Systems, Inc.
• Inventors: Lampropoulos, Fred P., Taylor, Steven R., Foote, Jerrold L., Salisbury, Jeffrey D.
• Primary Examiner(s): Yasko, John D.
• Assistant Examiner(s): CERMAK, ADAM
• Application Number:
  US08/224,653
• Time in Patent Office: 561 Days
• Field of Search: 604/49-55, 604/96-103, 604/118, 604/121, 604/151-155, 606/192-196, 600/18
• US Class Current: 604/509
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 25/10182 Injector syringes
• CPC Class Codes: A61M 25/10184 Means for controlling or monitoring inflation or deflation
• CPC Class Codes: A61M 25/10188 Inflation or deflation data displays
• CPC Class Codes: G01D 9/00 Recording measured values

Abstract

An electronically controlled syringe system for connection to a balloon catheter for automatically monitoring, displaying and recording inflation or deflation data. A syringe applies and releases pressure to and from the balloon catheter. A transducer housed on the syringe barrel emits at atmospheric pressure a signal by which both the syringe and transducer are recognizable to the system as a particular type of syringe. The system prompts the user to verify the recognized type of syringe. The system prompts the user to verify the recognized type of syringe. The transducer, which can be calibrated, senses fluid pressures applied by the syringe. The signal output by the transducer is input to a controller where the signal is digitally processed so as to derive and record therefrom data representing the magnitude of applied fluid pressure and the length of time that pressure is applied by the syringe. The data is automatically displayed and recorded. The syringe system permits input of various control parameters, such as a maximum positive inflation pressure and maximum duration for applying pressure.

Claims

1. 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 and recording data comprising the steps of:

equalizing the internal pressure of the syringe barrel to ambient atmospheric pressure; and

executing a transducer zeroing step comprising the steps of;

detecting an electromagnetic zeroing signal that is output by a transducer means, in fluid communication with the internal pressure of the syringe barrel, for detecting pressure and for outputting a voltage in proportion thereto, said zeroing signal being not equal to zero volts at ambient atmospheric pressure;

converting said zeroing signal to a digital zeroing signal using a means for A/D signal conversion;

inputting said digital zeroing signal to a means for digital signal processing; and

automatically electronically digitally processing the digital zeroing signal using said digital processor means to automatically compute and record in said digital signal processor means a numerical transducer offset representing ambient atmospheric pressure.

2. The method recited in claim 1, wherein said digital signal processing step further comprises the step of computing said transducer offset from both said digital zeroing signal and a predetermined numerical monitor offset that is stored in said digital processor means, said monitor offset representing an output voltage signal that is both substantially constant and inherent to the electronic circuitry of the A/D signal conversion means.

3. A method as recited in claim 1, further comprising the steps of:

closing off the syringe barrel from ambient atmospheric pressure; and

executing an inflation-deflation step comprising the steps of;

inflating the balloon member by pushing the plunger into the syringe barrel so as to increase both the internal pressure of the syringe barrel and the pressure applied to the balloon member;

detecting an electromagnetic pressure signal output by the transducer means;

converting the pressure signal to a digital pressure signal using the means for A/D signal conversion;

automatically electronically digitally processing the digital pressure signal so as to automatically derive and automatically record in the digital signal processor means, using both the digital pressure signal and the transducer offset, electronic digital data representing the magnitude of the internal pressure in the syringe barrel and the length of time that fluid pressure is applied to the balloon member;

electronically outputting a visual display of the magnitude and the corresponding length of time that fluid pressure is applied to the balloon member; and

deflating the balloon member by pulling the plunger toward the rear of the syringe barrel so as to decrease the internal pressure in the syringe barrel.

4. A method as recited in claim 3, wherein the step of automatically electronically digitally processing the digital pressure signal further comprises:

waiting for the detected electromagnetic pressure signal output by the transducer means to be equivalent to a predetermined threshold level of internal pressure in the syringe barrel prior to beginning measurement of the length of time that fluid pressure is applied to the balloon member.

5. A method as defined in claim 3, further comprising:

the step of repeating said inflation-deflation step in connection with a second inflation of the balloon member.

6. The method recited in claim 3, further comprising the steps of:

disconnecting said pressure transducer means from communication with said digital processor means;

reconnecting said pressure transducer means to said digital processor means;

electronically visually outputting a system user prompt requesting acknowledgement that said syringe barrel is reconnected;

electronically accepting a negative or positive syringe reconnection acknowledgement input from an input means operated by a system user; and

executing said transducer zeroing step when the negative syringe reconnection acknowledgement is input from the input means by the system user.

7. The method recited in claim 3, wherein the step of automatically electronically digitally processing the digital pressure signal further comprises the step of:

recording said automatically derived electronic digital data representing the magnitude of the internal pressure in the syringe barrel and the length of time that fluid pressure is applied to the balloon member only when the internal pressure in the syringe barrel exceeds a predetermined magnitude for a predetermined duration.

8. 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 and recording data comprising the steps of:

filling up said syringe barrel with a liquid fluid;

electromagnetically coupling a transducer means for detecting pressure and for outputting a voltage in proportion thereto with a means for digital signal processing, said transducer means being in fluid communication with internal pressure of the syringe barrel;

removing any pressure in the syringe barrel that is above atmospheric pressure; and

executing a transducer zeroing step comprising the steps of;

detecting an electromagnetic zeroing signal that is output by the transducer means, said zeroing signal being not equal to zero volts at ambient atmospheric pressure;

converting said zeroing signal to a digital zeroing signal using a means for A/D signal conversion;

inputting said digital zeroing signal to the digital processing means; and

automatically electronically digitally processing the digital zeroing signal using said digital processor means to automatically compute and record in said digital signal processor means a numerical transducer offset.

9. The method recited in claim 8, wherein said digital signal processing step further comprises the step of computing said transducer offset from both said digital zeroing signal and a predetermined numerical monitor offset that is stored in said digital processor means, said monitor offset representing an output voltage signal that is both substantially constant and inherent to the electronic circuitry of the A/D signal conversion means.

10. The method as recited in claim 8, further comprising the steps of:

disconnecting the electromagnetic coupling of the transducer means from the digital processor means;

connecting the balloon catheter member through the tubing to the syringe barrel;

recoupling the transducer means to said digital processor means;

electronically visually outputting a system user prompt requesting acknowledgement that said syringe barrel is reconnected;

electronically accepting a negative or positive syringe reconnection acknowledgement input from an input means operated by a system user; and

executing said transducer zeroing step when the negative syringe reconnection acknowledgement is input from the input means by the system user.

11. The method recited in claim 10, further comprising the step of executing an inflation-deflation routine comprising the steps of:

inflating the balloon member by advancing the plunger into the syringe barrel so as to increase both the internal pressure of the syringe barrel and the pressure applied to the balloon member;

detecting an electromagnetic pressure signal output by the transducer means;

converting the pressure signal to a digital pressure signal using the means for A/D signal conversion;

automatically electronically digitally processing the digital pressure signal so as to automatically derive and automatically record in the digital signal processor means, using both the digital pressure signal and the transducer offset, electronic digital data representing the magnitude of the internal pressure in the syringe barrel and the length of time that fluid pressure is applied to the balloon member;

electronically outputting a visual display of the magnitude and the corresponding length of time that fluid pressure is applied to the balloon member; and

deflating the balloon member by pulling the plunger toward the rear of the syringe barrel so as to decrease the internal pressure in the syringe barrel.

12. The method recited in claim 11, wherein the step of automatically electronically digitally processing the digital pressure signal further comprises the step of:

recording the automatically derived electronic digital data representing the magnitude of the internal pressure in the syringe barrel and the length of time that fluid pressure is applied to the balloon member only when the internal pressure in the syringe barrel exceeds a predetermined magnitude for a predetermined duration.

13. The method recited in claim 11, further comprising the step of repeating said inflation-deflation step in connection with a second inflation of the balloon member.

14. A system for monitoring inflation of a balloon-type member, and for automatically recording balloon-type member inflation data, said system comprising:

a syringe connectable so as to be in fluid communication with the balloon-type member through a length of tubing, the syringe comprising a barrel and a plunger selectively operable to inflate the balloon-type member by applying fluid pressure thereto through the length of tubing by sliding the plunger into the barrel;

transducer means, in fluid communication with said syringe and the length of tubing, for sensing the applied fluid pressure and for outputting an electromagnetic pressure signal proportional to the applied fluid pressure, the transducer means having a substantially constant non-zero voltage electromagnetic output signal at a substantially ambient atmospheric sensed fluid pressure;

means for convening said electromagnetic signal output from the transducer means into a digital pressure signal;

means for outputting a visual display;

digital processor means, electrically connected to the display means, for processing the digital pressure signal so as to electronically monitor, display and record the pressure applied to the balloon-type member, and the duration of the inflation of the balloon-type member by performing the programmed steps of;

deriving data from the digital pressure signal converted by the means for converting, which represents the constant non-zero voltage electromagnetic output signal at substantially ambient atmospheric sensed fluid pressure;

deriving data from said digital pressure signal which represents a numerical value of the magnitude of said applied pressure which is compensated by offsetting from said numerical value the constant non-zero voltage output signal of the transducer means;

deriving data from said digital pressure signal and from a system clock signal which represents a numerical value of the duration of said applied pressure;

electronically storing all said derived data for later retrieval and output;

automatically displaying said numerical values of the duration of inflation pressure and the magnitude of said applied pressure in a visually perceptible manner to a system user on said display means;

data memory means for storing the digital data derived by said digital processor means for later retrieval and output; and

program memory means for storing machine-readable instructions utilized by said digital processor means to carry out said programmed steps.