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CN-121977807-A - In-vitro measurement system and method for determining correction coefficient of balloon catheter

CN121977807ACN 121977807 ACN121977807 ACN 121977807ACN-121977807-A

Abstract

The invention discloses an in-vitro measurement system and method for determining a correction coefficient of a balloon catheter. The system comprises a constant temperature module and a correction measurement module, wherein the constant temperature module comprises a closed loop formed by connecting a liquid storage tank, a power pump and a test module sequentially through pipelines, the closed loop is provided with a flow sensor and a pressure sensor, the power pump is in communication connection with the correction measurement module so that the correction measurement module can control the rotating speed of the power pump, a balloon catheter is arranged in the test module, the test module is used for simulating a blood vessel channel in a human body, an external thermistor extension line, a proximal extension tube and a distal extension tube of the balloon catheter are respectively connected to the correction measurement module through signal lines, and a heating device and a temperature sensor are arranged in the constant temperature module and are connected with the correction measurement module. The invention can accurately correct the pressure and heart displacement measurement results of the balloon catheter, has simple structure and operation, and can improve the accuracy of clinical measurement.

Inventors

  • LIU GUANGMAO
  • HU SHENGSHOU
  • Lv shen

Assignees

  • 中国医学科学院阜外医院深圳医院(深圳市孙逸仙心血管医院)

Dates

Publication Date
20260505
Application Date
20260318

Claims (8)

  1. 1. The in-vitro measurement system for determining the correction coefficient of the balloon catheter is characterized by comprising a constant temperature module and a correction measurement module, wherein the constant temperature module comprises a closed loop formed by connecting a liquid storage tank, a power pump and a test module through pipelines in sequence, and the closed loop is provided with a flow sensor and a pressure sensor; the power pump is in communication connection with the correction measurement module, so that the correction measurement module can control the rotating speed of the power pump to adjust the flow and the pressure in the closed loop; The balloon catheter is arranged in the test module, the test module is used for simulating a blood vessel channel in a human body, and an external thermistor extension line, a proximal extension tube and a distal extension tube of the balloon catheter are respectively connected to the correction measurement module through signal wires so as to obtain the blood temperature, the external proximal pressure and the external distal pressure of the balloon catheter; The constant temperature module is internally provided with a heating device and a temperature sensor, and the temperature sensor is connected with the correction measurement module.
  2. 2. The extracorporeal measurement system for determining a correction factor of a balloon catheter of claim 1, wherein the correction measurement module controls the operation of the heating device to maintain a closed loop blood temperature range of 37.3 ± 0.3 ℃ based on the temperature detected by the temperature sensor.
  3. 3. The extracorporeal measurement system for determining a correction factor of a balloon catheter according to claim 1, wherein the power pump is an extracorporeal medical blood pump, and the flow rate of the power pump is calibrated before measurement, ensuring that the flow rate accuracy is + -0.1 mL/min.
  4. 4. An in vitro measurement system for determining the correction factors of balloon catheters according to claim 3, characterized in that said medical blood pump is a magnetic levitation centrifugal blood pump or a peristaltic pump.
  5. 5. The in vitro measurement system for determining the correction factor of a balloon catheter according to claim 1, wherein the test module is in the shape of a straight cylinder or a curved cylinder, and has an inner diameter dimension of 20-25 mm.
  6. 6. A method of determining a heart displacement correction factor using the in vitro measurement system according to any one of claims 1 to 5, comprising the steps of: (1) Adjusting the rotating speed of the power pump, detecting through a flow sensor and enabling the closed loop to reach the target flow; (2) Setting injection volume, injection speed and temperature of cold solution, wherein the injection volume is 5-10mL, the injection speed is 2-5 mL/s, and the temperature of the cold solution is 0-23 ℃; (3) Measuring the initial temperature of blood through a thermistor extension line, and selecting the average temperature within approximately 30 seconds as the calculated initial temperature of blood; (4) Injecting a cold solution through an extension tube at the proximal end of the balloon catheter, and obtaining a blood thermal dilution curve by the balloon catheter; (5) The correction measurement module reversely calculates the heart displacement correction coefficient K of the balloon catheter according to the thermal dilution curve and the Stewart-Hamilton formula.
  7. 7. The method of determining a displacement-from-center correction factor according to claim 6, wherein the target flow range is 2-8L/min, the condition adjustment is performed at intervals of 1-L/min, the displacement-from-center correction factor K under each condition is repeatedly measured at least 3 times, and an arithmetic average is taken.
  8. 8. A method of determining a pressure correction factor using the in vitro measurement system according to any of claims 1 to 5, comprising the steps of: (1) The rotating speed of the power pump is regulated, and the rotating speed is detected by an in-vivo pressure sensor, so that the near end and the far end of the testing module reach target pressure values; (2) Measuring blood pressure of the proximal and distal orifices of the balloon catheter by in vivo proximal and distal pressure sensors, respectively; (3) Leading out blood in the test module through the external proximal extension tube and the external distal extension tube and collecting corresponding pressure; (4) And respectively comparing the internal pressure value with the external pressure value at the near end and the far end to obtain the pressure drop loss of the balloon catheter cavity, thereby correcting the pressure value.

Description

In-vitro measurement system and method for determining correction coefficient of balloon catheter Technical Field The invention belongs to the field of medical instruments, and particularly relates to an in-vitro measurement system and method for determining a correction coefficient of a balloon catheter. Background Balloon catheters are widely applied to diagnosis and treatment of cardiovascular diseases, and the accuracy of parameters such as blood pressure and cardiac output measured by the balloon catheters directly influences clinical diagnosis and treatment effects. Measuring cardiac output by thermal dilution is one of the main methods of grasping cardiac output of patients in clinic, and the principle is to inject cold saline into pulmonary artery, record the temperature change of blood by using a temperature sensor at the tip of catheter, and calculate cardiac output in combination with injection parameters. The accuracy of measuring cardiac output depends largely on the accuracy of correction coefficients used to correct measurement deviations due to catheter design, cold solution characteristics, physiological disturbances and other factors, so that the measurement results are closer to the real cardiac output. However, in actual measurement, the correction coefficient (key parameter related to physical properties of blood and response speed of catheter) is easily affected by factors such as blood flow speed, blood temperature, viscosity, cold solution injection speed, etc., which indirectly leads to measurement errors. In addition, the patient's blood pressure is typically measured extracorporeally through a small-sized lumen of the balloon catheter, which, due to the small lumen diameter, can result in a degree of pressure drop loss, which can also lead to deviations of the measurement from the actual blood pressure value. Therefore, it is necessary to confirm the pressure and heart displacement correction coefficients of the balloon catheter. At present, the measurement of the correction coefficient of the balloon catheter is mostly dependent on in-vivo experiments, and the problems of complex operation, high cost, high risk and the like exist, so that the correction coefficient is difficult to be widely developed to sufficiently verify and optimize. More importantly, the in-vitro measurement device or method of the correction coefficient is still in a technical blank state at present. Disclosure of Invention The invention aims to provide an in-vitro measurement system and method for determining the correction coefficient of a balloon catheter, which have the advantages of simple structure, convenient operation and accurate measurement, and can simultaneously determine heart displacement and pressure correction values without complex in-vivo experiments. In order to achieve the above purpose, the present invention adopts the following technical scheme: the system comprises a constant temperature module and a correction measurement module, wherein the constant temperature module comprises a closed loop formed by connecting a liquid storage tank, a power pump and a test module sequentially through pipelines, and the closed loop is provided with a flow sensor and a pressure sensor; the power pump is in communication connection with the correction measurement module, so that the correction measurement module can control the rotating speed of the power pump to adjust the flow and the pressure in the closed loop; The balloon catheter is arranged in the test module, the test module is used for simulating a blood vessel channel in a human body, and an external thermistor extension line, a proximal extension tube and a distal extension tube of the balloon catheter are respectively connected to the correction measurement module through signal wires so as to obtain the blood temperature, the external proximal pressure and the external distal pressure of the balloon catheter; The constant temperature module is internally provided with a heating device and a temperature sensor, and the temperature sensor is connected with the correction measurement module. Further, the correction measurement module controls the heating device to work according to the temperature detected by the temperature sensor, so that the temperature range of the blood in the closed loop is maintained at 37.3+/-0.3 ℃. Furthermore, the power pump is an extracorporeal medical blood pump, and the flow of the power pump is calibrated before measurement, so that the flow speed precision is ensured to be +/-0.1 mL/min. Further, the medical blood pump is a magnetic suspension centrifugal blood pump or a peristaltic pump. Further, the test module is in a straight cylinder shape or a curved shape, and the inner diameter size is 20-25 mm. A method for determining a heart displacement correction factor using the in vitro measurement system, comprising the steps of: (1) Adjusting the rotating speed of the power pump, detecting through a flow senso