Shuttle valve

A shuttle valve comprising:

• a body defining an interior chamber;
• an inlet port, an outlet port and a common port, each of the ports being coupled to the body;
• a shuttle translatably disposed within the chamber between a first position wherein the inlet port and the common port are fluidicly coupled and the common port and the outlet port are fluidicly uncoupled and a second position wherein the outlet port and the common port are fluidicly coupled and the common port and the inlet port are fluidicly uncoupled;
• a first check valve coupled to the inlet port in a manner to permit fluid flow through the inlet port into the chamber and to prevent fluid from discharging from the chamber through the inlet port;
• a second check valve coupled to the outlet port in a manner to permit fluid to discharge from the chamber through the outlet port and to prevent fluid from flowing through the outlet port into the chamber;
• and
• a vent passage having a first end communicating with the interior chamber and a second end opening onto an outer surface of the body, wherein a portion of the interior chamber is vented to atmospheric pressure via the vent passage.

A shuttle valve comprising:

• a body defining an interior chamber;
• an inlet port, an outlet port and a common port, each of the ports being coupled to the body;
• a shuttle translatably disposed within the chamber between a first position wherein the inlet port and the common port are fluidicly coupled and the common port and the outlet port are fluidicly uncoupled and a second position wherein the outlet port and the common port are fluidicly coupled and the common port and the inlet port are fluidicly uncoupled;
• a first check valve coupled to the inlet port in a manner to permit fluid flow through the inlet port into the chamber and to prevent fluid from discharging from the chamber through the inlet port;
• a second check valve coupled to the outlet port in a manner to permit fluid to discharge from the chamber through the outlet port and to prevent fluid from flowing through the outlet port into the chamber;
• wherein the shuttle comprises:
• a substantially cylindrical body portion having an external surface with a first diameter;
• a longitudinally extending passage having a proximal end fluidicly coupled with the common port and a distal end terminating within the body portion of the shuttle;
• and
• a plurality of radially extending passages, each fluidicly coupled with the distal end of the longitudinally extending passage at one end thereof and opening onto the external surface at the other end thereof.

A shuttle valve comprising:

• a body defining an interior chamber;
• an inlet port, an outlet port and a common port, each of the ports being coupled to the body;
• a shuttle translatably disposed within the chamber between a first position wherein the inlet port and the common port are fluidicly coupled and the common port and the outlet port are fluidicly uncoupled and a second position wherein the outlet port and the common port are fluidicly coupled and the common port and the inlet port are fluidicly uncoupled;
• a first check valve coupled to the inlet port in a manner to permit fluid flow through the inlet port into the chamber and to prevent fluid from discharging from the chamber through the inlet port;
• a second check valve coupled to the outlet port in a manner to permit fluid to discharge from the chamber through the outlet port and to prevent fluid from flowing through the outlet port into the chamber;
• wherein:
• the body of the shuttle valve has a substantially cylindrical inner surface having a first diameter;
• the shuttle includes a body portion having a substantially cylindrical outer surface with a second diameter less than the first diameter;
• the shuttle further includes a plurality of longitudinally spaced seals extending outwardly from the body portion of the shuttle and disposed in slidable, sealing engagement with the inner surface of the body of the shuttle valve, the seals defining first, second and third annular cavities within the chamber between the outer surface of the body portion of the shuttle and the inner surface of the body of the shuttle valve, the first annular cavity being disposed proximate one end of the body portion and the third annular cavity being disposed proximate the other end of the body portion, the second annular cavity being disposed intermediate the first and third annular cavities;
• the second cavity is in fluid communication with the common port and one of the inlet and outlet ports with the other of the inlet and outlet ports being in fluid communication with one of the first and third cavities, whereby fluid flow is permitted between the common port and one of the inlet and outlet ports and fluid flow between the inlet and outlet ports is prevented.

A system for dispensing a medical fluid intravenously to a patient comprising:

• a shuttle valve having a body defining an interior chamber, and having an inlet port, an outlet port and a common port;
• an unbiased shuttle translatably disposed within the chamber between a first position wherein the inlet port and the common port are fluidicly coupled and the common port and outlet port are fluidicly uncoupled and a second position wherein the outlet port and the common port are fluidicly coupled and the common port and the inlet port are fluidicly uncoupled;
• a first check valve coupled to the inlet port in a manner to permit fluid flow through the inlet port into the chamber and to prevent fluid from discharging from the chamber through the inlet port;
• a second check valve coupled to the outlet port in a manner to permit fluid to discharge from the chamber through the outlet port and to prevent fluid from flowing through the outlet port into the chamber;
• a first section of tubing coupled at one end thereof to the inlet port and configured at an opposite end thereof for coupling to a reservoir of the fluid to be dispensed to the patient;
• and
• a second section of tubing coupled at one end thereof to the outlet port and configured at the other end thereof to be coupled to a patient.

A method for automatically selecting the ports of a valve in a fluid dispensing system to be fluidicly coupled, the valve including a body defining an interior chamber and further including an inlet port, an outlet port and a common port, each port being coupled to the body, the method comprising the steps of:

• coupling a first check valve to the inlet port in a manner to permit fluid flow through the inlet into the chamber and to prevent fluid from discharging from the chamber through the inlet port;
• coupling a second check valve to the outlet port in a manner to permit fluid to discharge from the chamber through the outlet port and to prevent fluid from flowing through the outlet port into the chamber;
• disposing a shuttle within the interior chamber so that the shuttle is translatable between a first position wherein the inlet port and common port are fluidicly coupled and the common port and outlet port are fluidicly uncoupled and a second position wherein the outlet port and the common port are fluidicly coupled and the common port and the inlet port are fluidicly uncoupled;
• venting at least a portion of the interior chamber to atmosphere.

A method for dispensing a medical fluid intravenously to a patient comprising:

• obtaining a shuttle valve having a body defining an interior chamber and further including inlet, outlet and common ports, each coupled to the body, a first check valve coupled to the inlet port in a manner to permit fluid flow through the inlet port into the interior chamber and to prevent fluid from discharging from the interior chamber through the inlet port, and a shuttle translatably disposed within the chamber;
• inducing a negative pressure at the common port causing the shuttle to be disposed in a first position wherein the inlet port and the common port are fluidicly coupled and the common port and the outlet port are fluidicly uncoupled;
• and
• inducing a positive pressure at the common port causing the shuttle to be disposed in a second position wherein the outlet port and the common port are fluidicly coupled and the common port and the inlet port are fluidicly uncoupled;
• wherein the shuttle changes position from the first position to the second position and from the second position to the first position solely in response to pressure of fluid intended to be communicated through the common port.