Disposable blood pressure transducer and monitor interface

• US 20060009699A1
• Filed: 07/08/2004
• Published: 01/12/2006
• Est. Priority Date: 07/08/2004
• Status: Active Grant

• Current Assignee: Edwards Lifesciences Corporation
• Original Assignee: Edwards Lifesciences Corporation
• Inventors: Roteliuk, Luchy, Phan, Luong N., West, Weldon Dean, Meyer, Douglas Jr.
• Granted Patent: US 7,604,602 B2
• Time in Patent Office: Days
• US Class Current: 600/486
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/02158 provided with two or more sensor elements
• CPC Class Codes: A61B 5/029 Measuring or recording blood output from the heart, e.g. minute volume A61B8/065 takes precedence

Abstract

A medical blood pressure transducer that provides an identifier to a monitor that conveys characteristics of the transducer. The monitor can use the information to decide whether to function, or in calibration of the system. The transducer may be part of a disposable blood pressure monitoring system, and may include two transducers closely-spaced to provide two separate but identical outputs. In this way, the transducer may be connected to both a patient monitor and a cardiac output monitor at the same time measurements from a single line can be simultaneously supplied to two separate monitoring devices (for example a patient monitor and a cardiac output monitor). The identifier for the transducer may be circuitry, specifically a resistance/capacitance (RC) combination that possesses a characteristic time constant.

Claims

1. A medical fluid pressure sensing system, comprising:

a pressure transducing device, comprising;

a. a pressure-sensitive transducer capable of externally measuring fluid pressures and converting those pressures into electrical signals;

b. an identifier which characterizes the pressure transducing device; and

a signal receiving device adapted to communicate with the pressure transducing device and receive the electrical signals and being capable of sensing the identifier and therefore the characteristics of the pressure transducing device when placed in communication therewith.

2. The system of claim 1, wherein the pressure transducing device is a fluid pressure transducing device which further comprises:

c. a housing having a conduit in which fluid may enter;

d. wherein the pressure-sensitive transducer is mounted in the housing for measuring fluid pressures in the conduit and converting those pressures into electrical signals.

3. The system of claim 2, wherein the fluid pressure transducing device further comprises:

e. an electrical cable connected to the pressure transducer for transmitting the signals;

f an electrical connector on the cable for transmitting the signals from the cable; and

wherein the signal receiving device is adapted to physically and electrically communicate with the connector and is capable of sensing the identifier and therefore the characteristics of the fluid pressure transducing device when placed in communication with the connector.

4. The system of claim 1, wherein the pressure-sensitive transducer directly senses fluid pressure.

5. The system of claim 4, wherein the fluid is blood and the signal receiving device is a cardiac output monitor.

6. The system of claim 5, further including a second pressure-sensitive transducer mounted in the housing for measuring fluid pressures in the conduit and converting those pressures into electrical signals, and a patient monitor adapted to communicate with the second pressure transducing device.

7. The system of claim 1, wherein the identifier introduces an electrical signature to the signals, and wherein the signals and signature can be recognized by the signal receiving device.

8. The system of claim 7, wherein the electrical signature is selected from the group consisting of:

a time-based feature; and

a frequency-based feature.

9. The system of claim 1, wherein the identifier is selected from a group consisting of the following:

a combination of a resistor, a capacitor, and/or an inductor;

a memory chip;

a reference voltage/current;

an electromagnetic signature;

an active or passive switch which can be electrically, mechanically, optically, or magnetically triggered; and

an optical identifier.

10. The system of claim 1, wherein the identifier comprises electrical circuitry.

11. The system of claim 10, wherein the electrical circuitry comprises a resistance/capacitance (RC) combination that possesses a characteristic time constant.

12. The system of claim 11, wherein the pressure transducing device further comprises:

e. an electrical cable connected to the pressure transducer for transmitting the signals;

f. an electrical connector on the cable for transmitting the signals from the cable, wherein the connector includes electrical contact pins and a capacitor bridging two of the pins that provides the capacitance in the RC combination; and

wherein the signal receiving device is adapted to physically and electrically communicate with the connector and is capable of sensing the identifier and therefore the characteristics of the pressure transducing device when placed in communication with the connector.

13. The system of claim 11, wherein the signal receiving device includes decision-making circuitry that will only permit functioning of the system depending on a determination of the time constant.

14. The system of claim 13, wherein the decision-making circuitry will only permit functioning of the system if the time constant is within 20% of a reference value.

15. A medical fluid pressure transducing device, comprising:

a housing having a conduit in which fluid may enter;

a pressure-sensitive transducer mounted in the housing for measuring fluid pressures in the conduit and converting those pressures into electrical signals; and

an electrical identifier that characterizes the type of fluid pressure transducing device.

16. The fluid pressure transducing device of claim 15, wherein the pressure-sensitive transducer directly senses fluid pressure.

17. The fluid pressure transducing device of claim 15, wherein the identifier introduces an electrical signature to the signals that can be recognized by a signal receiving device adapted to communicate with the connector.

18. The fluid pressure transducing device of claim 17, wherein the electrical signature is selected from the group consisting of:

a time-based feature; and

a frequency-based feature.

19. The fluid pressure transducing device of claim 15, wherein the electrical identifier is selected from a group consisting of the following:

a combination of a resistor, a capacitor, and/or an inductor;

a memory chip;

a reference voltage/current; and

an electro-magnetic signature.

20. The fluid pressure transducing device of claim 15, further including;

an electrical cable connected to the pressure transducer for transmitting the signals; and

an electrical connector on the cable for transmitting the signals from the cable,

wherein the electrical identifier comprises circuitry on the housing, the transducer, the cable, or the connector.

21. The fluid pressure transducing device of claim 15, wherein the electrical identifier comprises a resistance/capacitance (RC) combination that possesses a characteristic time constant.

22. The fluid pressure transducing device of claim 21, further including;

an electrical cable connected to the pressure transducer for transmitting the signals; and

an electrical connector on the cable for transmitting the signals from the cable,

wherein the connector includes electrical contact pins and the transducer includes a capacitor bridging two of the pins that provides the capacitance in the RC combination.

23. The system of claim 15, further including a second pressure-sensitive transducer mounted in the housing for measuring fluid pressures in the conduit separately from the first pressure-sensitive transducer and converting those pressures into electrical signals.

24. A dual fluid pressure transducing device, comprising:

an external housing adapted to connect to an in-dwelling catheter, the housing having a conduit in which fluid may enter, the fluid therefore being placed in communication with a lumen of the in-dwelling catheter;

two pressure sensors mounted in the housing for measuring fluid pressures in the conduit and converting those pressures into electrical signals; and

an electrical connector connected to each pressure transducer for transmitting the signals.

25. The dual fluid pressure transducing device of claim 24, wherein the pressure sensors directly sense fluid pressure.

26. The dual fluid pressure transducing device of claim 24, further including a stopcock assembly interposed between the housing conduit and the in-dwelling catheter for opening the conduit to the atmosphere and providing a reference pressure in a fluid column defined within the conduit at a particular elevation, the pressures sensed by the two pressure sensors being the same along the fluid column.

27. The dual fluid pressure transducing device of claim 24, wherein the assembly of one of the pressure sensors and associated connector includes an identifier that characterizes the type of pressure sensor.

28. The dual fluid pressure transducing device of claim 27, wherein the two connectors are differently colored.

29. The dual fluid pressure transducing device of claim 24, wherein the housing further includes a single snap tab for permitting flow through the conduit and generating a square pressure wave within the fluid in the conduit that can be detected by the two pressure sensors.

30. A method of measuring fluid pressure from a location within a patient, comprising:

inserting a catheter into a body vessel or cavity;

providing an external housing connected to the catheter having a conduit in which fluid may enter, the fluid therefore being placed in communication with a lumen of the catheter, the housing having at least one fluid pressure sensor mounted therein for measuring fluid pressures in the conduit and converting those pressures into electrical signals; and

transmitting signals representing two measurements of fluid pressure from the at least one fluid pressure sensor to at least one signal receiving monitor.

31. The method of claim 30, wherein there are two fluid pressure sensors, and the signals representing two measurements of fluid pressure derive one from each sensor.

32. The method of claim 31, further including an electrical connector associated with each fluid pressure sensor, the method further including connecting the two connectors to different signal receiving monitors.

33. The method of claim 32, wherein the assembly of one of the fluid pressure sensors and associated connector includes an identifier that characterizes the type of pressure sensor, the method further including detecting the identifier with the monitor and adjusting signal processing accordingly.

34. The method of claim 30, further including transmitting the signals representing two measurements of fluid pressure to two different signal receiving monitors.

35. The method of claim 34, wherein the fluid is blood and one monitor is a patient monitor and the other is a cardiac output monitor.

36. A method of measuring fluid pressure from a location within a patient, comprising:

providing a pressure-sensitive transducer capable of externally measuring fluid pressures and converting those pressures into electrical signals, and having an identifier associated therewith that characterizes the pressure-sensitive transducer;

providing a signal receiving device adapted to communicate with the pressure-sensitive transducer and receive the electrical signals and being capable of sensing the identifier and therefore the characteristics of the pressure-sensitive transducer when placed in communication therewith;

placing the pressure-sensitive transducer in fluid pressure communication with a patient fluid;

placing the signal receiving device in communication with the pressure-sensitive transducer; and

sensing the characteristics of the pressure-sensitive transducer via the identifier and consequently adjusting a reception configuration of the signal receiving device.

37. The method of claim 36, wherein the fluid is blood and the signal receiving device is a cardiac output monitor, the reception configuration including an amplification level.

38. The method of claim 37, further including:

providing a housing having the first pressure-sensitive transducer and a second pressure-sensitive transducer also capable of externally measuring fluid pressures and converting those pressures into electrical signals; and

transmitting signals representing measurements of fluid pressure from the second pressure-sensitive transducer to a patient monitor.

39. The method of claim 37, wherein the identifier introduces an electrical signature to the signals, and wherein the signals and signature can be recognized by the signal receiving device.

40. The method of claim 39, wherein the electrical signature is selected from the group consisting of:

a time-based feature; and

a frequency-based feature.

41. The method of claim 37, wherein the identifier is selected from a group consisting of the following:

a combination of a resistor, a capacitor, and/or an inductor;

a memory chip;

a reference voltage/current;

an electromagnetic signature;

an active or passive switch which can be electrically, mechanically, optically, or magnetically triggered; and

an optical identifier.

42. The method of claim 37, wherein the identifier comprises electrical circuitry.

43. The method of claim 42, wherein the electrical circuitry comprises a resistance/capacitance (RC) combination that possesses a characteristic time constant.