Method and device for optimizing the measurement accuracy in vivo when measuring invasive blood pressure using a fluid-filled catheter-manometer system

A method for optimizing the measurement accuracy in vivo when measuring invasive blood pressure using a fluid-filled catheter-manometer system comprising:

• a medical signal processing device;
• a catheter filled with a sterile fluid;
• a pressure line filled with a sterile fluid, the pressure line having one or more stopcocks or couplings and being connected to the catheter;
• a pressure transducer-flush system unit filled with a sterile fluid, the pressure transducer-flush system unit being connected to the pressure line and to a pressurised storage bag filled with a sterile fluid;
• a pressure transducer integrated into the pressure transducer-flush system unit, the pressure transducer being provided with a membrane configured for converting a pressure signal into an electric signal and for transmitting said electric signal to the medical signal processing device;
• and
• a flush system integrated into the pressure transducer-flush system unit, the flush system being configured for ensuring that a continuous flush from the storage bag to the catheter is maintained, the flush system being provided with a manually operable element configured for temporarily, briefly opening the flush system and closing it again, or for temporarily opening the flush system for a longer time,
• the method comprising:
• calculating a natural frequency and a damping coefficient of the fluid-filled catheter-manometer system;
• calculating a dynamic response diagram of the fluid-filled catheter-manometer system by using said natural frequency and said damping coefficient;
• calculating an inverted dynamic response diagram of the fluid-filled catheter-manometer system;
• using said inverted dynamic response diagram as a filter to process a signal measured by the pressure transducer;
• and
• afterwards, calculating an invasive blood pressure signal and an invasive blood pressure values from the processed signal.

A device for optimizing the measurement accuracy in vivo when measuring invasive blood pressure using a fluid-filled catheter-manometer system, the device comprising:

• a medical signal processing device;
• a catheter filled with a sterile fluid;
• a pressure line filled with a sterile fluid, the pressure line having one or more stopcocks or couplings and being connected to the catheter;
• a pressure transducer-flush system unit filled with a sterile fluid, the pressure transducer-flush system unit being connected to the pressure line and to a pressurised storage bag filled with a sterile fluid;
• a pressure transducer integrated into the pressure transducer-flush system unit, the pressure transducer being provided with a membrane configured for converting a pressure signal into an electric signal and for transmitting said electric signal to the medical signal processing device;
• and
• a flush system integrated into the pressure transducer-flush system unit, the flush system being configured for ensuring that a continuous flush from the storage bag to the catheter is maintained, the flush system being provided with a manually operable element configured for temporarily, briefly opening the flush system and closing it again, or for temporarily opening the flush system for a longer time,
• the medical signal processing device being configured for:
• calculating a natural frequency and a damping coefficient of the fluid-filled catheter-manometer system;
• calculating a dynamic response diagram of the fluid-filled catheter-manometer system by using said natural frequency and said damping coefficient;
• calculating an inverted dynamic response diagram of the fluid-filled catheter-manometer system using said dynamic response diagram;
• using said inverted dynamic response diagram as a filter to process a signal measured by the pressure transducer;
• and
• afterwards, calculating an invasive blood pressure signal and an invasive blood pressure values from the processed signal.