CA2067855C - Fluid sampling device - Google Patents

Abstract

A fluid sampling device in which a resilient element held between an actuator and a probe drives the tip of the latter sealingly against a source of fluid, and creates a negative pressure at the tip on its removal from the source.

Description

_ 74424-47 FLUID SAMPLING DEVICE
Field of the Invention This invention relates to devices for sampling fluids, and more particularly for sampling blood flowing in a line with disengagement control.
Background of the Invention It is known in the art that the number of needle insertions is desirably minimized; and that valving may be used to permit a plurality of samples to be successively taken, with if desired different syringes, from one needle site. It is known that a stopcock can be used here to control flow. It is known too to incorporate a check valve in a blood specimen collection device, to prevent blood backflow into the patient. Use of an elasto-merically receding member to create a negative pressure upon the end of dispensing from, for example, a syringe, to prevent undesirable fluid movement after the desired dispensing is known.
Summary of the Invention It has been discovered that repeated sampling, as from a single needle site, can be carried out, with simplicity, economy, freedom from septa and undue waveform compromise, and cleaning difficulties, if there is provided, with a valve for fluid, a probe to operatively engage the valve, and an actuator, a resilient member deformed by actuator movement to resiliently force the probe into operative engagement with the valve to sealingly engage the probe, and resuming its undeformed configuration upon reverse movement of the actuator, to produce a negative pressure at the probe tip.

- la -In accordance with the present invention, there is provided a fluid sampling device which comprises a probe for sealingly engaging a fluid container, an actuator for movement relative to said probe, and resilient means connected between said probe and said actuator, said resilient means being arranged to urge said probe against said fluid container when said actuator is moved in one direction, and to create a negative pressure when said actuator is moved in the opposite direction.
In preferred embodiments, the resilient member is elastomeric and placed under compression in movement of a . ~ ~ 20678S5 probe tip toward the valve; the probe tip is elastomeric and engages a stopcock valving portion; Luer male threads on a housing-actuator engage female Luer threads on a stopcock to move the probe toward the valve; there is a passage through the probe and housing to a check valve permitting flow only in a direction away from the stopcock; and a fitting with female Luer threads is provided just downstream of the check valve.
Preferred Embodiment Description of the preferred operation follows:
drawing, structure, and operation.
Drawing There is shown in the drawing a side elevation of the preferred embodiment, partially in section, and partially diagrammatic.
Structure The preferred embodiment is shown generally at 10.
Housing 12, of injection molded polycarbonate, is solvent-bonded to a female-threaded Luer connector 14, also of injection molded polycarbonate, and carries disk check valve 16 (of 0.040 inch thick Dow Corning Silastic medical grade sheet-ing) in deeper counterbore 18.
Depending from the counterbore 18 portion of housing 12 is probe engagement portion 20, also of injection molded polycarbonate, with inwardly directed rim 22 which engages rim 24 of probe 26.
Probe 26 includes ledge 28, an upper surface of which supports elastomeric barrel 30, and tip 32 which receives and carrie~ elastomeric tip 34, selectively engageable with valving element 36 of stopcock 38, which is connected (by means not shown) to a blood flow line.

2.o67 85~

Barrel 30 ls of compresslon-molded slllcone sold by Lexlngton Medlcal, South Hlll, South Carollna, under the deslgnatlon "Dow 4-2483". It ls 0.0400 lnches ln axlal dlmenslon, has an outslde dlameter of 0.275 lnches, and a wall thlckness through lts maln body of 0.040 lnches.
The upper portlon of stopcock 38 lncludes female Luer threads 40, whlch engage male threads 42 wlthln houslng 12.
Operatlon In operatlon, blood ls flowlng through stopcock 38 from a slngle needle slte, the stopcock valvlng portlon 36 belng rotated so that the two coaxlal portlons of the valvlng portlon openlng are allgned wlth stopcock flow path portlons 44 and 46. The valvlng portlon ls then rotated to the posltlon shown ln the flgure, and houslng 12 rotated to axlally compress barrel elastomerlc portlon 30, whlch ln turn drlves elastomerlc tlp 34 lnto seallng engagement wlth valvlng portlon 36.
A syrlnge may then be engaged wlth the female thread of connector 14, and blood drawn through passage 48, 50, and 52 of probe tlp 32, probe 26, and houslng 12, through check valve 16, and (through a passage not shown) lnto Luer connector 14.
When houslng 12 ls rotated the other way, after rotatlng the stopcock valve portlon for lnllne flow once more, barrel element 30 creates a negatlve pressure seallng check valve 16 and sucklng back any blood contalned ln the probe tlp passage 48.
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Claims (6)

1. A fluid sampling device which comprises a probe for sealingly engaging a fluid container, an actuator for movement relative to said probe, and resilient means connected between said probe and said actuator, said resilient means being arranged to urge said probe against said fluid container when said actuator is moved in one direction, and to create a negative pressure when said actuator is moved in the opposite direction.

2. The device of claim 1 in which said resilient means is an elastomeric element compressibly mounted between said actuator and said probe.

3. The device of claim 2 in which said resilient means is generally barrel shaped.

4. The device of claim 3 in which said resilient means has rims generally circular in cross-section, and of thickness greater than the remainder of the wall of said means.

5. The device of claim 2 in which said resilient means is held between a counterbore in said actuator and a ledge on said probe.

6. The device of claim 1 in which said probe includes an elastomeric tip.