INDUCTION TYPE ARTERY GAGE

• US 3,661,148 A
• Filed: 04/13/1970
• Issued: 05/09/1972
• Est. Priority Date: 04/13/1970
• Status: Expired due to Term

• Current Assignee: Alexander Kolin
• Original Assignee: Alexander Kolin
• Inventors: Kolin, Alexander
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Howell, Kyle L.
• Application Number:
  US05/027,516
• Time in Patent Office: 757 Days
• Field of Search: 128/2,2.5F,2.5R,2.5D,2.5P,2.5V 33/147N 324/34,37,10,71
• US Class Current: 600/481
• CPC Class Codes: A61B 5/1076 for measuring dimensions inside body cavities, e.g. using catheters A61B3/1005 takes precedence
• CPC Class Codes: G01B 7/13 Internal diameters

Abstract

An improved induction type gage is provided which is intended to be used to measure the diameter of a blood vessel within a living subject, and to provide a means for detecting and measuring slight pulsating variations in the diameter of the blood vessel. The gage includes, for example, a collapsible frame and primary and secondary electric inductance windings attached to the frame. The gage may be introduced percutaneously, for example, into the blood vessel to be measured, and it is constructed to constrict as it is so introduced and subsequently to expand when it has entered the blood vessel to span the inner diameter of the blood vessel. An alternating electric current is then passed through the primary winding and the resulting voltage induced in the secondary winding is measured and is an indication of the diameter of the blood vessel.

Claims

1. An electromagnetic type catheter gage for measuring the inner diameters of conduits, or the like, comprising:

a primary inductance winding having first and second sides defining a loop, said sides being resiliently biassed from one another and collapsible towards one another;

electric lead means connected to said primary winding for connection to an alternating current supply to cause alternating current to flow through said primary winding;

a secondary inductance winding mounted in an electromagnetic inductive relationship with said primary winding and across which a voltage is induced, said secondary windings having first and second sides adjacent said first and second sides of said primary winding to define said loop, said sides of said secondary winding being resiliently biassed from one another and collapsible towards one another, the voltage induced across said secondary winding being a function of the transverse dimension of said loop;

metering means for measuring the voltage across said secondary winding; and

further electric lead means connecting said secondary winding to said metering means.

2. The electromagnetic gage defined in claim 1, and which includes a loop-shaped resilient frame attached to at least one of said windings for maintaining said first and second sides thereof resiliently spaced from one another.

3. The electromagnetic gage defined in claim 1, and which includes a loop-shaped resilient frame of electrically conductive material and serving as one of the aforesaid windings.

4. The electromagnetic gage defined in claim 2, and which includes a flexible tubular member attached to said loop-shaped resilient frame and serving as a conduit for said electric leads.

5. The electromagnetic gage defined in claim 2, in which said loop-shaped resilient frame is formed of stainless steel.