Guidewire with pressure and temperature sensing capabilities

• US 7,097,620 B2
• Filed: 09/19/2002
• Issued: 08/29/2006
• Est. Priority Date: 09/02/1994
• Status: Expired due to Fees

• Current Assignee: Volcano Corporation (Koninklijke Philips N.V.)
• Original Assignee: Volcano Corporation (Koninklijke Philips N.V.)
• Inventors: Ortiz, John E, Obara, Robert Z., Corl, Paul D.
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US10/247,391
• Publication Number:
  US 20030018273A1
• Time in Patent Office: 1,440 Days
• Field of Search: 600/486, 600/488
• 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 guide wire having pressure sensing capabilities for measuring the pressure of liquid in a vessel comprising a flexible elongate member and having proximal and distal extremities and having an outside diameter of 0.018″ or less. The distal extremity of said flexible elongate member is adapted to be disposed in the liquid in said vessel. A housing is carried by the flexible elongate member and has a diameter substantially the same as the diameter of the flexible elongate member. The housing has a space therein with a pressure sensor mounted in the space in the housing. The pressure sensor has a diaphragm that is sensitive to changes of pressure in the liquid in the vessel. The diaphragm is rectangular in shape and is bordered by a rim surrounding the well. A backing plate is formed of an insulating material bonded to the crystal and serves to reinforce the rim of the crystal of semiconductor material. The backing plate has a cavity therein underlying the diaphragm and is in substantial registration with the diaphragm. The cavity serves to provide a pressure reference.

Claims

1. A pressure sensor apparatus having pressure sensing capabilities, the pressure sensor apparatus comprising:

a guidewire having a maximum diameter of 0.018″

or less;

a sensor housing having an external wall and a lumen, the sensor housing disposed near a distal extremity of the guidewire;

a coil disposed proximally from the sensor housing;

a solid state pressure sensor comprising a diaphragm and secured to the housing; and

an ultrasonic transducer disposed distally from the pressure sensor.

2. The pressure sensor apparatus of claim 1, further comprising a control console electrically coupled to the pressure sensor and the ultrasonic transducer.

3. The pressure sensor apparatus of claim 2, wherein the control console is adapted to determine pressure and flow velocity at a distal region of the pressure sensor apparatus based on measurements obtained from the pressure sensor and measurements obtained from the ultrasonic transducer.

4. The pressure sensor apparatus of claim 1, wherein the pressure sensor further comprises a semiconductor crystal.

5. The pressure sensor apparatus of claim 1, wherein the ultrasonic transducer is adapted to measure flow velocity at a distal region of the pressure sensor apparatus.

6. The pressure sensor apparatus of claim 1, wherein the sensor housing comprises a cutout, and the pressure sensor is mounted in the cutout such that an outer surface of the pressure sensor is substantially flush with the external wall of the sensor housing.

7. The pressure sensor apparatus of claim 1, further comprising a second coil comprising a radiopaque material and disposed distally from the sensor housing.

8. A method for determining pressure at a target region within a patient'"'"'s vasculature, the method comprising:

providing a pressure sensor apparatus having a guidewire with a maximum diameter of 0.018″

or less, a sensor housing disposed near a distal extremity of the guidewire, a solid state pressure sensor secured to the housing, and an ultrasonic transducer disposed near the distal extremity;

disposing the distal extremity of the pressure sensor apparatus at the target region within the patient'"'"'s vasculature;

obtaining measurements from the pressure sensor;

obtaining measurements from the ultrasonic transducer; and

analyzing the measurements from the pressure sensor and the measurements from the ultrasonic transducer to determine pressure and flow velocity at the target region.

9. The method of claim 8, further comprising:

providing a control console,

wherein obtaining measurements from the pressure sensor, obtaining measurements from the ultrasonic transducer, and analyzing the measurements are performed with the control console.

10. The method of claim 8, wherein the target region comprises a vascular stenosis.

11. The method of claim 10, further comprising:

determining a first pressure on a proximal side of the stenosis;

determining a second pressure on a distal side of the stenosis; and

comparing the first and second pressures to determine a severity of the stenosis.

12. The method of claim 11, further comprising:

advancing an angioplasty catheter having a balloon over the pressure sensor apparatus; and

dilating the stenosis with the balloon.

13. A pressure sensor apparatus having pressure sensing capabilities, the pressure sensor apparatus comprising:

a guidewire having a maximum diameter of 0.018″

or less, a proximal end, and a distal end;

a sensor housing having an external wall and a lumen, the sensor housing disposed on the distal end of the guidewire;

a coil disposed at a proximal end of the sensor housing and comprising a radiopaque material;

a solid state pressure sensor comprising a diaphragm and secured to the housing; and

an end cap disposed on the distal end of the guidewire where the end cap comprises an ultrasonic transducer.