Method of measuring blood pressure and velocity proximally and distally of a stenosis

• US 6,767,327 B1
• Filed: 08/21/2000
• Issued: 07/27/2004
• Est. Priority Date: 09/02/1994
• Status: Expired due to Term

• Current Assignee: Volcano Corporation (Koninklijke Philips N.V.)
• Original Assignee: Volcano Therapeutics, Inc. (Koninklijke Philips N.V.)
• Inventors: Ortiz, John E., Obara, Robert Z., Corl, Paul D.
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US09/644,111
• Time in Patent Office: 1,436 Days
• Field of Search: 600/486, 600/488, 600/505
• US Class Current: 600/486
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/6851 Guide wires
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61M 2025/0002 with a pressure sensor at the distal end
• CPC Class Codes: A61M 2025/09008 having a balloon
• CPC Class Codes: A61M 2025/09083 having a coil around a core
• CPC Class Codes: A61M 25/09 Guide wires
• CPC Class Codes: A61M 25/10 Balloon catheters A61M25/0125 takes precedence; embolectomy A61B17/22032; retractors A61B17/02; inflatable balloons for placing stents or stent-grafts A61F2/958 ; stomach balloons for treatment of obesity A61F5/0003; oesophagal tubes A61J15/00
• CPC Class Codes: G01L 19/0084 to the outside of the housing other details about the housing see G01L19/14
• CPC Class Codes: G01L 19/141 Monolithic housings, e.g. molded or one-piece housings
• CPC Class Codes: G01L 19/147 Details about the mounting of the sensor to support or covering means
• CPC Class Codes: G01L 19/149 of immersion sensor, e.g. where the sensor is immersed in the measuring medium or for in vivo measurements, e.g. by using catheter tips
• CPC Class Codes: G01L 9/0054 integral with a semiconducting diaphragm

Abstract

A method of measuring blood pressure and velocity proximally and distally of a stenosis in a vessel carrying blood includes the steps of providing a guide wire having both a pressure sensor and a velocity sensor disposed on a distal region of the guide wire, introducing the guide wire into the vessel, advancing the guide wire to position the pressure sensor and the velocity sensor proximally and distally of the stenosis, and measuring the blood pressure and velocity proximally and distally of the stenosis with the pressure sensor and the velocity sensor.

Claims

1. A method of measuring blood pressure and velocity proximally and distally of a stenosis in a vessel carrying blood, comprising the steps of:

introducing a guide wire carrying a solid state pressure sensor and a velocity transducer into the vessel, the guide wire having a core wire extending from a proximal region to a distal region of the guide wire, the pressure sensor and the velocity transducer disposed on a distal region of the guide wire,

advancing the guide wire to position the pressure sensor and the velocity transducer proximally and distally of the stenosis, and

measuring blood pressure and velocity proximally and distally of the stenosis with the pressure sensor and the velocity transducer carried by the guide wire.

2. The method of claim 1 wherein the pressure sensor operates at a relatively low frequency and the velocity transducer operates at a relatively high frequency.

3. The method of claim 2 wherein the velocity transducer is operated at a frequency on the order of 10 MHz.

4. The method of claim 1 wherein the pressure sensor and velocity transducer are coupled to a common set of conductors.

5. The method of claim 1 wherein the pressure sensor and velocity transducer are coupled to a common set of conductors.

6. The method of claim 1 wherein the step of measuring blood pressure and velocity comprises the steps of:

first measuring the blood pressure and velocity proximally of the stenosis, and

subsequently measuring the blood pressure and velocity distally of the stenosis.

7. The method of claim 1 wherein the step of measuring blood pressure and velocity comprises the steps of:

first measuring the blood pressure and velocity distally of the stenosis, and

subsequently measuring the blood pressure and velocity proximally of the stenosis.

8. The method of claim 1 further comprising the steps of:

advancing an angioplasty catheter having a balloon thereon over the guide wire to the location of the stenosis, and

dilating the stenosis with a balloon.

9. The method of claim 1 further comprising the step of dilating a balloon carried by the guide wire at the location of the stenosis.

10. A method of measuring blood pressure proximally and distally of a stenosis in a vessel carrying blood, comprising the steps of:

advancing a guide wire having a core wire extending from a proximal region to a distal region of the guide wire and carrying a solid state pressure sensor disposed on a distal region of the guide wire within the vessel to position the pressure sensor relative to the stenosis, and measuring blood pressure proximally and distally of the stenosis with the pressure sensor, wherein the blood pressure is measured by monitoring changes in a pair of resistive elements which respond oppositely to changes in pressure but are affected in a similar manner by changes in temperature.

11. A method of measuring blood pressure proximally and distally of a stenosis in a vessel carrying blood, comprising the steps of:

introducing a guide wire carrying a first pressure sensor into the vessel,

introducing a catheter carrying a second pressure sensor into the vessel over the guide wire,

advancing the guide wire within the vessel to position the first sensor distally of the stenosis,

advancing the catheter within the vessel to position the second sensor proximally of the stenosis,

measuring blood pressure distally of the stenosis with the first sensor, and

measuring blood pressure proximally of the stenosis with the second sensor.

12. The method of claim 11 including the steps of taking pressure measurements with the two sensors proximal of the stenosis, and equalizing the two measurements before advancing the guide wire to position the first sensor distally of the stenosis.

13. The method of claim 11 wherein the blood pressure is measured by monitoring changes in a pair of resistive elements which respond oppositely to changes in pressure but are affected in a similar manner by changes in temperature.

14. The method of claim 11 wherein the first pressure sensor is a solid state sensor.

15. A method of determining whether an angioplasty procedure is appropriate for treatment of a stenosis in a vessel carrying blood, comprising the steps of:

advancing a guide wire having a core wire extending from a proximal region to a distal region of the guide wire with a solid state pressure sensor and a velocity transducer disposed on a distal region of the guide wire into the vessel so that the pressure sensor and the velocity transducer are positioned proximally of the stenosis,

measuring the pressure and the velocity of the blood in the vessel on the proximal side of the stenosis,

advancing the guide wire through the stenosis so that the pressure sensor and the velocity transducer are positioned distally of the stenosis,

measuring the pressure and the velocity of the blood in the vessel on the distal side of the stenosis, and

determining whether an angioplasty procedure is appropriate for treatment of the stenosis on the basis of the pressure and velocity measurements.

16. The method of claim 15, wherein the pressure sensor operates a relatively low frequency and the velocity transducer operate at a relatively high frequency.

17. The method of claim 15 wherein the velocity transducer operates at approximately 10 MHz.

18. The method of claim 15 wherein the pressure sensor and velocity transducer are coupled to a common set of conductors.

19. A method of measuring blood pressure and velocity proximally and distally of a stenosis in a vessel carrying blood, comprising the steps of:

providing a guide wire having both a pressure sensor and a velocity sensor disposed on a distal region of the guide wire, the guide wire having a core wire extending from a proximal region to a distal region of the guide wire,

introducing the guide wire into the vessel,

advancing the guide wire to position the pressure sensor and the velocity transducer proximally and distally of the stenosis, and

measuring blood pressure and velocity proximally and distally of the stenosis with the pressure sensor and the velocity sensor.

20. The method according to claim 19 wherein the pressure sensor is a solid state pressure sensor.

21. The method according to claim 19 wherein the velocity sensor is a transducer.

22. The method of claim 19 further comprising the step of determining whether an angioplasty procedure is appropriate for treatment of the stenosis on the basis of the pressure and velocity measurements.

23. The method of claim 19 wherein the step of measuring blood pressure and velocity comprises the steps of:

first measuring the blood and velocity proximally of the stenosis, and

subsequently measuring the blood pressure and velocity distally of the stenosis.

24. The method of claim 19 wherein the step of measuring blood pressure and velocity comprises the steps of:

first measuring the blood pressure and velocity distally of the stenosis, and

subsequently measuring the blood pressure and velocity proximally of the stenosis.

25. The method of claim 19 further comprising the steps of:

advancing an angioplasty catheter having a balloon thereon over the guide wire to the location of the stenosis, and

dilating the stenosis with a balloon.

26. The method of claim 19 further comprising the step of dilating a balloon carried by the guide wire at the location of the stenosis.

27. The method of claim 19, wherein the step of advancing the guide wire comprises the steps of positioning both the pressure sensor and the velocity transducer proximally of the stenosis and positioning both the pressure and velocity transducer distally of the stenosis.

28. The method of claim 27, wherein the step of measuring blood pressure and velocity comprises the steps of measuring both blood pressure and velocity proximally of the stenosis and measuring both blood pressure and velocity distally of the stenosis.