Apparatus for enlarging a vessel or clearing obstructive tissue from a vessel according to vessel compliance

• US 5,084,060 A
• Filed: 02/15/1989
• Issued: 01/28/1992
• Est. Priority Date: 02/15/1989
• Status: Expired due to Fees

• Current Assignee: Vastek
• Original Assignee: Freund Precision, Inc.
• Inventors: Freund, Robert F., Kelly, William C. M.
• Primary Examiner(s): Hafer, Robert A.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/311,126
• Time in Patent Office: 1,077 Days
• Field of Search: 606/191-195, 606/27, 604/100, 604/95, 604/96, 604/97, 604/99
• US Class Current: 606/192
• CPC Class Codes: A61M 25/10184 Means for controlling or monitoring inflation or deflation
• CPC Class Codes: A61M 25/10187 Indicators for the level of inflation or deflation
• CPC Class Codes: A61M 25/104 used for angioplasty
• CPC Class Codes: G01D 9/00 Recording measured values

Abstract

An apparatus for clearing obstructive tissue from a body vessel or enlarging the lumen of the vessel comprises a balloon catheter which is insertable into the vessel of a patient to position the balloon in the area to be enlarged or against the obstructive tissue. A syringe is provided to incrementally inflate the balloon with a reasonably incompressible fluid to apply pressure against the inside of the vessel for opening the vessel. A pressure transducer senses fluid pressure in the balloon and an interval timer is used to monitor the rate of change in this fluid pressure. The rates of change in fluid pressure between the incremental inflations are monitored to determine vessel compliance, to determine when the stenosis is cleared, and to indicate when the vessel is stretched to, or near, its elastic limit.

Claims

1. An apparatus for applying pressure to the inside of a vessel during selected intervals to enlarge the lumen of the vessel which comprises:

a fluid inflatable means positionable inside the vessel;

means connected in fluid communication with said inflatable means for introducing fluid to said inflatable means to apply pressure against the vessel;

a transducer operatively connected with said inflatable means for generating a signal indicative of the fluid pressure in said inflatable means; and

automatic means for determining a time interval between incremental inflations of said inflatable means;

a monitor connected with said transducer and with said time interval determining means and having a screen means for displaying said transducer pressure signal and as a function of said interval signal.

2. An apparatus as recited in claim 1 wherein said inflatable means is a balloon catheter.

3. An apparatus as recited in claim 2 wherein said means for introducing fluid to said inflatable means is a syringe which comprises:

a fluid chamber in fluid communication with said balloon catheter; and

a plunger threadably advanceable into said chamber to introduce fluid into said balloon catheter.

4. An apparatus as recited in claim 3 wherein said transducer is mounted on said syringe in fluid contact with fluid in said chamber.

5. An apparatus as recited in claim 4 wherein said monitor comprises means for directly comparing said transducer pressure signal with said interval signal.

6. An apparatus as recited in claim 5 further comprising a recorder electrically connected with said monitor to chronicle variations of said transducer pressure signal during selected time intervals.

7. An apparatus for dilating a body vessel which comprises:

an inflatable balloon positionable inside the vessel;

means in fluid communication with said balloon for incrementally inflating said balloon with a fluid;

automatic means for establishing a time interval between incremental inflations;

means mounted on said inflation means for sensing changes in fluid pressure in said balloon during said time interval between incremental inflations; and

means operatively connected with said sensing means for indicating when changes in fluid pressure fall below a selected level during said interval.

8. An apparatus as recited in claim 7 wherein said balloon is mounted on a balloon catheter.

9. An apparatus as recited in claim 8 wherein said inflating means is a syringe which comprises:

a fluid chamber in fluid communication with said balloon catheter; and

a plunger advanceable into said chamber to introduce fluid into said balloon catheter.

10. An apparatus as recited in claim 9 wherein said sensing means is a transducer for generating an electrical signal which is indicative of fluid pressure in said balloon.

11. An apparatus as recited in claim 10 further comprising a clock for generating an interval signal, said clock being operatively connected with said indicating means.

12. An apparatus as recited in claim 11 wherein said indicating means is a monitor connected with said transducer and with said clock and having a screen for displaying said transducer pressure signal and said interval signal.

13. An apparatus as recited in claim 12 wherein said monitor comprises means for directly comparing said transducer pressure signal with said interval signal.

14. An apparatus as recited in claim 13 further comprising a recorder electrically connected with said monitor to chronicle variations of said transducer pressure signal during selected time intervals.

15. A method for using a balloon catheter system to clear obstructive tissue from the lumen of a body vessel which automatically records, processes and displays data comprising the steps of:

(a) positioning the expandable balloon of the balloon catheter in the lumen across the obstruction;

(b) incrementally increasing the fluid pressure in the system by mechanical means to inflate the balloon and establish a new base pressure after each incremental increase in pressure;

(c) establishing an interval signal which begins when each new base pressure is attained;

(d) measuring fluid pressure changes from the base pressure during the interval; and

(e) deflating the balloon when changes from the base pressure do not exceed a prescribed level during the interval.

16. A method for using a balloon catheter system to enlarge the lumen of a body vessel which atomically records, processes, and displays data comprising the steps of:

(a) positioning the expandable balloon of the balloon catheter in the lumen;

(b) incrementally increasing the fluid pressure in the system by mechanical means to inflate the balloon and establish a new base pressure after each incremental increase in pressure;

(c) establishing an interval signal which begins when each new base pressure is attained;

(d) measuring fluid pressure changes from the base pressure during the interval; and

(e) deflating the balloon when changes from the base pressure do not exceed a prescribed level during the interval.