Fluid Extraction Device

Abstract

An instant vacuum fluid extraction device in the form of a vial sealed at one end by a valve and having an axially movable piston member therein shiftable from extended to retracted positions for generating a vacuum within the sealed container during movement to retracted position and means for latching the piston in its retracted position.

Description

This invention relates to a device for extraction of an increment of fluid from a vessel or other supply source, such as a sample of blood, body fluid or the like specimen and it relates more particularly to a device which operates under vacuum to effect withdrawal into a sealed container through a hypodermic needle or the like.

To the present, blood specimens are taken by the insertion of a hollow needle into the blood vessel after which the fluid is withdrawn under vacuum in response to the rearward displacement of a piston member through the vial while the needle remains in the vessel. This operation is slow and time consuming and requires the use of both hands as well as very steady hands to effect the desired rearward movement of the piston while retaining the needle in the inserted position.

It is an object of this invention to produce a device of the type described in which a vacuum can be generated in the vial immediately prior to use so that, upon insertion of the needle into the vessel for the withdrawal of a liquid specimen, the vacuum conditions existing in the vial can be made effective for the smooth and rapid withdrawal of fluid without the need for further manipulation, which can be operated with one hand to effect fluid specimen removal, and which is simple in construction and easy in operation thereby to enable use without the need for highly skilled or technical labor.

These and other objects and advantages of this invention will hereinafter appear and for purposes of illustration, but not of limitation, embodiments of the invention are shown in the accompanying drawings, in which

FIG. 1 is a sectional elevational view of the device embodying the features of this invention with the elements in their normal assembled relationship for storage or shipment;

FIG. 2 is a sectional elevational view of the device shown in FIG. 1 with the piston member retracted for generation of subatmospheric conditions within the interior of the vial immediately prior to use;

FIG. is a sectional elevational view of the device shown in FIGS. 1 and 2 after the specimen has been taken and the actuator removed to enable shipment or storage of the device with the specimen sealed therein; and

FIGS. 4, 5 and 6 are similar to FIGS. 1, 2 and 3 with a modified form of the device.

Referring now to the drawings, the device comprises an elongate tubular member 10, in the form of a vial of glass, plastic, and the like preferably transparent and translucent material, which is open at its forward end 11 and closed by the rear wall 12 having a slot 13 of rectangular or other polygonal shape extending therethrough.

The forward open end of the vial is formed with a beaded inturned portion 14 adapted to be received in sealing engagement within a peripheral groove 15 in the rearward end portion of a resilient valve member 16 of rubberlike material which is adapted to seal the open forward end of the vial.

The resilient valve member has a plug portion 17 which extends into the vial at its forward end and a portion which extends forwardly beyond the end of the vial with a passage extending continuously through the plug from the rearward end to the forward end except for a segment which subdivides the passage into aligned rearward and forward sections 18 and 19 respectively in which the segment 20 is beyond the end of the vial and is formed with a slit 21 extending in a plane radial to the axis of the passage with the slit extending from the forward end of the rearward passage 18 to the rearward end of the forward passage 19 to effect communication between the passages, when in open position, but which is effective to seal the passages, when in closed position.

The slit operates as a valve which can be distorted to open position by pressing upon the plug alongside the segment from opposite directions in alignment with the slit.

The forward end portion of the valve is provided with a projection adapted to support a hub member 22 for gripping a hollow needle 23 having a portion which extends rearwardly into communication with the forward passage 19. An elongate cover is removably mounted on the hub to protect the needle during nonuse.

A piston and cylinder arrangement is provided in which the interior of the vial functions as the cylinder and the piston head is in the form of a tubular section 24 of resilient plastic or rubberlike material formed with one or more axially spaced ring members 25 dimensioned to extend outwardly into sealing engagement with the inner walls of the vial. Means are provided on the rearward end portion of the piston head, in alignment with the opening 13 for connection with an actuator 26 adapted slidably to extend through the opening 13 into engagement with the piston head 24. In the illustrated modification, the means on the end of the piston head comprises a threaded male member 27 and the actuator comprises an elongate rod 26 dimensioned to have a length slightly greater than the length of travel of the piston head through the vial and provided at its forward end with a threaded female section 28 for threadably receiving the threaded male member 27 thereby removably to connect the actuator with the piston.

It will be understood that other means may be provided removably to connect the actuator rod with the piston head to effect actual displacement of the piston head within the vial.

Means are provided, on the rearward end portion of the actuator rod, outwardly of the vial, for manual engagement to effect displacement of the rod into the vial for attachment and rearwardly of the vial for retraction of the piston head towards retracted position. Other means are provided in connection with the rod for latching the rod and piston in retracted position. One such means, illustrated in FIGS. 1 to 3, comprises pins or wings 30 extending laterally from opposite sides of the rod adjacent its forward end with the wings being dimensioned easily to pass through the slotted opening 13 when in alignment therewith but incapable of return passage therethrough when the actuator rod is turned to offset the wings from the openings.

Another means, illustrated in FIGS. 4 to 6, comprises a forwardly facing tubular section 40 joined at its rearward end onto an outwardly disposed portion of the actuator rod 26 and which is formed to a cross-sectional dimension slightly greater than the vial to enable the tubular member to telescope about the vial, when in normal position, but which tapers inwardly slightly towards the forward end so that, when the tubular member is displaced rearwardly to retracted position, the forward end of the tubular member will clear the rear wall of the vial with corresponding flexure of the ends of the tubular member inwardly whereby the rear wall of the vial functions as a stop, as illustrated in FIG. 5.

Normally, as illustrated in FIGS. 1 and 4, the piston head 24 is in its forward position within the tubular vial 10 with the actuator rod 26 extending through the opening 13 for attachment at its forward end to the piston plug and with the handle portion of the rod disposed outwardly of the vial for easy access.

When it is desired to make use of the extractor, the actuator rod is displaced rearwardly to effect corresponding movement of the piston until it reaches its retracted position of adjustment within the vial. As the piston is displaced rearwardly through the vial, it operates to pull a vacuum in the portions of the vial forwardly thereof. Return movement of the piston to relieve vacuum is prevented by the stop that exists as the wings 30 pass through the slots 13 with slight turning movement of the rod to offset the wings from the slots after they have passed therethrough.

In the modifications shown in FIGS. 4 to 6, return movement is prevented as the forward ends of the tubular section 40 clear the rearward end of the vial to enable deflection of the ends of the tubular member inwardly to engage the rear wall of the vial as a stop.

When locked in retracted position, the actuator means can be disconnected from the piston plug by unscrewing from the male member as illustrated in FIGS. 3 and 6. The device is then ready for use with a vacuum which has been generated in the vial immediately prior to use. The needle can then be inserted into the desired vessel and communication established by pressing on the valve alongside the slit to distort the closure sufficient to effect opening movement of the slit. Thus direct communication is established between the needle and the vacuum chamber to withdraw blood or body fluid from the vessel into the chamber. Momentary pressure on the valve will operate to withdraw only a small increment of body fluid for visual inspection to be certain that the needle has been properly inserted. Thereafter, the valve can be operated to withdraw as much of the fluid as desired to fill the vial.

It will be apparent that the device described is of simple construction and easy in operation to provide a container in which vacuum is instantly formed immediately prior to use for reliable operation and in which the vacuum container is constructed with a manually operated valve that permits selected amounts of body fluid to be withdrawn for testing the location of the needle or for withdrawal of variable amounts of fluid, as described.

It will be understood that changes may be made in the details of construction, arrangement and operation without departing from the spirit of the invention, especially as defined in the following claims.

Claims

I claim:

1. A fluid extraction device comprising a vial having openings at its forward and rearward ends in communication with the interior of the vial, a hollow needle, a valve member mounted on the forward end of the vial to seal the forward end of the vial with means on the forward end of the valve member for mounting the needle in alignment with the vial and a valve interposed between the end of the needle and the vial for sealing the vial when in normally closed position and for establishing communication between the interior of the vial and the needle when in operated position, a piston plug mounted for axial movement in sealing engagement with the interior wall of the vial between forward and retracted positions of adjustment, and actuator rod dimensioned to extend through the opening in the rearward end of the vial into connection with the piston plug for axial displacement of the plug between forward and retracted positions of adjustment with displacement toward retracted position being effected while the valve is in closed position to generate a vacuum within the vial between the piston plug and valve, and means for locking the plug in retracted position for maintaining vacuum conditions within the vial when the valve is closed.

2. An extraction device as claimed in claim 1 which includes a needle cover for covering the needle during nonuse.

3. An extraction device as claimed in claim 1 in which the valve is formed of a resilient material having a forward passage extending rearwardly from the forward end of the valve member and dimensioned to receive an end of the needle and a rearward passage extending forwardly from the rearward end of the plug in communication with the vial and a slitted portion extending from the forward end of the rearward passage to the rearward end of the forward passage for connecting said passages when in position.

4. An extraction device as claimed in claim 3 in which the slitted portion between the passages is located beyond the forward end of the vial to enable flexure alongside the slitted portion to open the slit.

5. An extraction device as claimed in claim 1 in which the piston plug comprises a cylindrical member formed of resilient material dimensioned to extend outwardly into sealing engagement with the surrounding walls of the vial.

6. An extraction device as claimed in claim 1 in which the means for locking the plug in retracted position comprises outwardly extending wings on the forward end portion of the actuator and a slotted opening in the rearward wall of the vial beyond which the wings extend when the piston plug is in retracted position whereby the plug, in retracted position, can be turned to offset the wings from the slotted opening.

7. An extraction device as claimed in claim 1 in which the means for locking the piston plug in retracted position comprises a tubular feed section connected with the actuator rod at its rearward end portion and dimensioned to overlap the vial, in its forward position, by an amount corresponding to the length of travel of the plug between forward and retracted position and having a cross-sectional dimension at its forward end snugly to embrace the vial whereby the rearward end wall of the vial confronts the end of the sleeve as it clears the vial in retracted position.

8. A method for providing a fluid extraction device as claimed in claim 1 with a vacuum for the extraction of fluid immediately prior to fluid extraction comprising the steps of displacing the piston plug in the vial from a forward position to a retracted position while the valve is in closed position to generate a vacuum within the vial, and latching the plug in retracted position to maintain the vacuum within the vial.

9. A method for fluid extraction comprising providing a fluid extraction device as claimed in claim 1 with a vacuum for the extraction of fluid immediately prior to fluid extraction by displacing the piston plug in the vial from a forward position to a retracted position while the valve is in closed position to generate a vacuum within the vial, latching the plug in retracted position to maintain the vacuum within the vial, inserting the needle into the source of fluid to be extracted, opening the valve for communicating the interior of the vial with the fluid source whereby the vacuum conditions existing within the vial effect withdrawal of fluid from the source into the vial.