Two-way outdwelling slit valving of medical liquid flow through a cannula and methods

• US 5,201,722 A
• Filed: 09/04/1990
• Issued: 04/13/1993
• Est. Priority Date: 09/04/1990
• Status: Expired due to Term

• Current Assignee: Navilyst Medical Incorporated (AngioDynamics, Inc.)
• Original Assignee: Robert H. Moorehead, Thomas A. Wiita
• Inventors: Moorehead, Robert H., Wiita, Thomas A.
• Primary Examiner(s): Yasko, John D.
• Assistant Examiner(s): Gutowski, Anthony
• Application Number:
  US07/577,941
• Time in Patent Office: 952 Days
• Field of Search: 604/30, 604/31, 604/167, 604/246, 604/247, 604/257, 137/493, 137/493.1, 137/493.8, 137/493.9, 137/512.4, 137/843-845, 137/859
• US Class Current: 604/247
• CPC Class Codes: A61M 2039/242 designed to open when a predetermined pressure or flow rate has been reached, e.g. check valve actuated by fluid
• CPC Class Codes: A61M 2039/2426 Slit valve
• CPC Class Codes: A61M 39/22 Valves or arrangement of valves A61M39/02, A61M39/0247, A61M39/16 take precedence; regulating valves in infusion systems A61M5/16881; in devices worn by the patient for the reception of urine, faeces, catamenial or other discharge, or in colostomy devices A61F5/4405
• CPC Class Codes: A61M 39/24 Check- or non-return valves

Abstract

A novel cardiovascular outdwelling, normally closed, pressure-responsive slit valve liquid flow control and related methods wherein a diaphragm having a slit therein is flexed distally by hydrostatic pressure and proximally by negative pressure at different points in time to selectively open the slit and accommodate the flow of IV solution to a medical patient through a cannula and blood sampling from the cardiovascular system of the patient through the cannula in such a way as to prevent bleed-back and clotting of blood within the cannula.

Claims

1. A cardiovascular assembly comprising:

a cannula comprising a hollow interior for placement, at a distal end therof, in a cardiovascular system of a patient;

a source of liquid disposed external of and above the patient at a height above the patient which provides a gravity caused liquid pressure for selective infusion flow;

a hollow tube disposed external of the patient, a proximal interior of the hollow tube being in communication with the liquid at the source;

two way valve structure interposed between the hollow tube and the cannula external of the patient, a proximal part of the two way valve structure being in communication with the interior of the hollow tube, at a distal end thereof, and a distal part of the two way valve structure being in communication with the hollow interior of the cannula, at a proximal end thereof;

the two way valve structure comprising centrally interior normally closed bi-directionally pressure-responsive slit valve means selectively accommodating liquid flow across the valve structure in a first direction without human involvement between the interiors of the hollow tube and the cannula when the pressure differential is controlled by the liquid from said source applied across said slit valve means and in a second direction between the interiors of the cannula and the hollow tube when an oppositely directed pressure differential is imposed across said slit valve means;

the two way valve structure comprising hollow housing means comprising means to which the slit valve means are sealingly secured peripherally, the hollow housing means comprise at least two parts fastened together by threaded connectors.

2. A cardiovascular assembly comprising:

a cannula comprising a hollow interior for placement, at a distal end thereof, in a cardiovascular system of a patient;

a source of liquid disposed external of and above the patient at a height above the patient which provides a gravity caused liquid pressure for selective infusion flow;

a hollow tube disposed external of the patient, a proximal interior of the hollow tube being in communication with the liquid at the source;

two way valve structure interposed between the hollow tube and the cannula external of the patient, a proximal part to the two way valve structure being in communication with the interior of the hollow tube, at a distal end thereof, and a distal part of the two way valve structure being in communication with the hollow interior of the cannula, at a proximal end thereof;

the two way valve structure comprising centrally interior normally closed bi-directionally pressureresponsive slit valve means selectively accommodating liquid flow across the valve structure in a first direction without human assistance between the interiors of the hollow tube and the cannula when the pressure differential is controlled by the liquid from said source is applied across said slit valve means and in a second direction between the interiors of the cannula and the hollow tube when an oppositely directed pressure differential is imposed across said slit valve means;

the two way valve structure comprising hollow housing means comprising means to which the slit valve means are sealingly secured peripherally;

the sealingly securing means comprising opposed abutment means which collectively compressively engage a peripheral portion of the slit valve means.

3. A cardiovascular assembly comprising:

a cannula comprising a hollow interior for placement, at a distal end thereof, in a cardiovascular system of a patient;

a source of liquid disposed external of and above the patient at a height above the patient which provides a gravity caused liquid pressure by which infusion selectively occurs;

a hollow tube disposed external of the patient, a proximal interior of the hollow tube being in communication with the liquid at the source;

two way valve structure interposed directly between the hollow tube and the cannula external of the patient, a proximal part to the two way valve structure being in communication;

with the interior of the hollow tube, at a distal end thereof, and a distal part of the two way valve structure being in communication with the hollow interior of the cannula, at a proximal end thereof;

the two way valve structure comprising centrally interior normally closed bi-directionally pressure-responsive slit valve means through which any flow occurs selectively accommodating liquid flow across the valve structure in either direction between the interiors of the hollow tube and the cannula;

the slit valve means comprising yieldable diaphragm means in which at least one slit is centrally disposed and flexed by pressure differential, and physical means adjacent to the diaphragm means constraining flexure of the diaphragm means to control the pressure differentials required to open the slit in either direction, the differential pressure across the slit valve means due to the gravity caused liquid pressure being sufficient without human intervention to open said slit in at least one direction.

4. An assembly according to claim 3 wherein the flexure-constraining means comprise first means distal of and second means proximal of the slit, which first and second means separately control at least in part the respective pressure differentials required to distally and proximally open the slit.

5. An assembly according to claim 3 wherein the flexure-constraining means comprise means accommodating flow through the slit in one direction at a lower pressure differential and in an opposite direction at a higher pressure differential.

6. An assembly according to claim 5 wherein the accommodating means comprise rigid structure located distal and proximal of the diaphragm means defining a relatively large flow opening in one direction away from the diaphragm means and a relatively small flow opening in an opposite direction away from the diaphragm means.

7. An assembly according to claim 6 wherein the distal and proximal rigid structure comprises distal and proximal aperture-defining means.

8. An assembly according to claim 6 wherein the valve structure comprises housing means and the distal and proximal rigid structure comprises means integral with the housing means.

9. A method of controlling medical liquid flow in a cannula comprising the steps of:

placing a distal end of the cannula indwelling within a medical patient;

connecting a distal end of an outdwelling slit valve housing directly to a proximal end of the cannula in selective internal liquid communication along a single direct predetermined flow path;

causing a normally closed slit diaphragm to be interposed across the flow path within the housing;

creating without human manipulation a predetermined liquid pressure differential across the diaphragm thereby flexing the diaphragm distally, opening the slit therein and causing proximal-to-distal flow therethrough and directly along the single flow path to the patient;

altering the pressure differential to an opposite predetermined amount across the diaphragm thereby flexing the diaphragm proximally, opening the slit therein and causing distal-to-proximal flow therethrough and directly along the single flow path from the patient.

10. A method of controlling liquid flow bi-directionally to and from a hollow cannula comprising the steps of:

causing a normally closed slit diaphragm to be closingly disposed across a single direct flow path comprising in part an outdwelling valve structure;

placing a distal end of the cannula indwelling within a medical patient;

connecting a distal end of the valve structure to the proximal end of the cannula so that the cannula defines another part of the flow path, the flow path portion of the valve structure being in direct communication with the flow path portion of the cannula;

creating a first predetermined liquid pressure differential based upon other than human manipulation across the diaphragm thereby flexing the diaphragm distally, opening the slit therein and causing direct proximal-to-distal flow therethrough to the patient;

altering the pressure differential to be oppositely directed and of a second higher amount across the diaphragm thereby flexing the diaphragm proximally, opening the slit therein and causing distal-to-proximal flow therethrough from the patient.