Background of the Invention
The invention relates to a device for selectively sampling fluid from two sections of a fluid conveying line.
It is known that in many fields of activity it is necessary to remove samples from two sections of a fluid conveyance line, such as, for example, the input and output sections of an apparatus, for controlling the changes effected on the fluid in passing through the apparatus itself.
This occurs, for example, in the field of extracorporeal blood circulation, when it is required to perform samplings of the blood at the input and at the output of an oxygenating apparatus.
The devices currently in use, formed for example by three-way taps coupled in series, have some disadvantageous characteristics, essentially constituted by large bulk and complicated operation, with operating modes which are frequently anything but evident.
Summary of the Invention
The aim of the present invention is to provide a device having small bulk and great operating simplicity.
The aim proposed, as well as objects which will become apparent hereinafter, are achieved by a device for selectively sampling fluid from two sections of a line, according to the invention, characterized in that it comprises a selecting element having an axial cavity, opening to the outside at an end intended for being associated with a syringe, and comprising a cylindrical appendix suitable for rotating, in consequence of a manual action on gripping elements, in a seat provided in a fixed element to which three conduits converge, the two end conduits being suitable for being connected respectively with the two sections of the line and the central conduit with a drain, said selecting element having two passages, each of which is suitable for establishing a communication between one of the end conduits and the central conduit, and a third passage in an intermediate position, suitable for establishing a communication selectively between the two end conduits and said axial cavity.
Brief Description of the Drawings
Further features and advantages will become better apparent from the description of a preferred, but not exclusive, embodiment of the invention, illustrated by way of non-limitative example only in the accompanying drawings, where:
FIG. 1 is a top view of the invention intended for sampling on the input and output lines of an apparatus for treating blood in extracorporeal circulation, with removed a part of the selecting element, which is in closed position;
FIG. 2 is a cross sectional view along the plane II--II of FIG. 1;
FIG. 3 is a cross sectional view along the plane III--III of FIG. 2;
FIG. 4 shows the sequence of operations for sampling the output of the apparatus;
FIG. 5 illustrates the sequence of operations for sampling the input of the apparatus.
Description of the Preferred Embodiment
With reference to the above figures, at 1 is generally indicated the selecting element, which has the axial cavity 2, open to the outside at the end 3, through which a sampling syringe can be introduced, by lowering the shutter 4 against the bias of the spring 5.
The selecting element 1 comprises the cylindrical appendix 6 suitable for rotating, in consequence of an operator acting on the gripping fins 7, inside a seat provided within the fixed element generally indicated at 8 and having a base plate 8a formation and a boss formation 8b projecting from the base plate formation 8a, to which three conduits or connectors converge, angularly spaced apart from each other by 90.degree.: the conduit 9 is intended to be connected with the output line of the apparatus, the conduit 10 with a drain or dump and the conduit 11 with the input line of the apparatus.
The appendix 6 comprises the two passages 12 and 13, suitable for establishing a communication between the conduit 10 and respectively the conduits 9 and 11, symmetrically arranged relatively to a plane passing through the rotation axis containing a third L-shaped passage 14, suitable for establishing a selective communication between the two conduits 9, 11 and the cavity 2, all of which will be better explained in the description of the operation. Note that passage 12 has an inlet opening 12a and an outlet opening 12b, passage 13 has an inlet opening 13a and an outlet opening 13b and passage 14 has an inlet opening 14a and an outlet aperture 14b (FIG. 4).
Rigidly coupled with the selecting element 1 is the disk 15, having a small port 15a suitable for allowing the reading of indications placed on the underlying disk 16, rigidly coupled with the fixed element 1 at the operating positions of said selecting element: thus, as an example, in the situation depicted in FIGS. 1, 2 and 3, through the small port 15a the indication STOP is read, since the device is in closed position, but by rotating the element 1 through 45.degree. clockwise, the indication SU will be read, which indicates "output drain", and by again rotating through 45.degree., the indication PU will be read, which indicates "output sampling".
Abutments or reference elements 50 (FIG. 2) symbolically illustrate means suitable for stopping the selecting element in the operating positions, and a limiter 51 symbolically illustrated in FIG. 2 prevents rotations greater than 90.degree. in the two directions from the position shown in FIGS. 1, 2 and 3, complete the device.
The operation of the invention is extremely simple; if it is desired to perform sampling of blood from the output of the apparatus, it is sufficient to proceed according to the sequence of FIG. 4: from the closing position, the selecting element 1 is rotated clockwise through 45.degree., so that the passage 12 establishes a communication between the conduit 9, which is connected with the output line of the device, and the conduit 10 to allow draining of a certain amount of blood, then said element 1 is rotated through additional 45.degree. so as to establish a communication between the passage 14 and the conduit 9, to allow blood to access the cavity 2 from which sampling is performed by means of a syringe.
FIG. 5 shows the sequence of operations for performing sampling of blood from the input of the apparatus: from closing position, the selecting element is rotated anticlockwise through 45.degree., so that the passage 13 establishes a communication between the drain 10 and the conduit 11, which is connected with the input line and, after some time, the selecting element is rotated through additional 45.degree., so as to establish a communication between the passage 14 and the conduit 11, consequently allowing blood to access the cavity 2.
From what has been described, it is seen that the invention provides an extremely simple structure with very small bulk, and that the operating modes are immediately perceivable due to their intrinsic simplicity and to the indications which can be read in the different phases.
The invention described is susceptible to numerous modifications and variations, all of which are comprised within the scope of the invention concept: thus, as an example, the conduits which converge to the seat on the fixed element can be separated by angles different from 90.degree., and consequently the shape of the passages of the selecting element will be dieferent.
In the practical implementation of the invention, all the elements may be replaced with other technically equivalent elements: furthermore, any materials, dimensions and shapes may be employed.