JPH0439991B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved perfusion bath for the study of human or animal tissue preserved in vitro.

Such studies are generally conducted in baths constructed entirely or in part of glass or similar transparent materials. Throughout such studies, it is necessary that the tissue be immersed in a physiologically balanced solution or other suitable fluid. This liquid has a controlled flow through the bath so that tissue debris and other debris can be removed from the bath. It is also necessary that the surface of the liquid be isolated from the surrounding air so that the gas content of this liquid can be maintained within predetermined levels.

Previously known types of such baths use drain pipes based on the overflow principle, so that as the liquid is being replenished, a surface portion of this liquid is constantly drained. One of the difficulties experienced with known bathtubs is that the outlet or outlets tend to become blocked due to surface tension.
Thus, undesirable fluctuations in the liquid level within the bathtub occur.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an improved bathtub that is capable of keeping the level of liquid in the bathtub substantially constant even when there are considerable fluctuations in the rate of liquid flowing into the bathtub. The goal is to provide the following.

Another object of the invention is to provide a bathtub which has a higher flow rate into the bathtub compared to previously known types of irrigation bathtubs.

A further object of the invention is to provide an irrigation bath that is less sensitive to vibrations of the tissue specimen contained within the bath than previously known types of irrigation baths.

Accordingly, one form of the invention is a bath for the study of human or animal tissue preserved in vitro, comprising: a body having a bathing cavity; means for allowing fluid to flow into said cavity; and means for causing the liquid to flow out from the cavity. In this bathtub, the means for causing liquid to flow out of the bath cavity includes a drainage path formed inside the bathtub wall, and the drainage path is configured to determine the highest liquid level in the bath cavity. It has a horizontal upper edge and is provided with means for regulating the flow of liquid from the bath.

In a preferred embodiment of the invention, the bathtub is constructed of a suitable plastic material so as to have an essentially open top box-like structure. The one or more walls are provided with a fluid inlet, preferably at least one opening in close proximity to the bathtub floor and communicating with the interior of the bathtub, to permit a controlled flow into the bathtub. 1 connected to the valve arrangement by a conduit system or the like so as to allow inflow into the valve system.
It has one or more openings. One wall is provided with a drain, the upper surface of which slopes downward from the bathtub and has an inlet to the drain which determines the height of the liquid in the bathtub. The liquid overflowing from the drain channel is completely transferred to a suitable drain pipe made in the bathtub wall and is subsequently disposed of.

Means are provided for controlling the flow of the drain. This means is preferably an elongated wedge-shaped closure device, which may also be made of plastic material, and is shaped to complementarily change the shape of the drainage channel. This closure device cooperates with the amount of liquid and the drainage path to regulate the amount of foreign matter passing through the drainage path into the drain pipe. Preferably, the drain passage spans the entire width of the bathtub;
In this way a relatively long path is provided for the drainage of excess liquid and other material from the bath. Means are provided to assist in easily adjusting the closure device in relation to the drainage path so that the proper drainage rate can be adjusted as a function of the inflow of liquid into the bathtub.

The bathtub is provided with at least one gas release opening made in one or more walls.
The gas release opening or openings are in communication with the gas supply through the manifold so that gas is discharged into the bath through the opening or openings and discharging the liquid in the bath. May flow near the surface. For this purpose, one or more gas release openings are spaced in a row in said wall and have a diameter sufficient to allow the desired amount of gas to flow over the surface of the liquid. are doing. The gas discharge opening is located slightly above the level of the upper edge of the drainage channel. The gas used may be a mixture of various gases known to those skilled in the art, the purpose of which is to provide the necessary protection to the contents of the bath by isolating the surface of the liquid from the surrounding air. One preferred embodiment of the gas is, for example, a mixture of 95% oxygen and 5% carbon dioxide.

Preferred embodiments of the invention will now be described with the help of the accompanying figures.

FIG. 1 is a perspective view of a preferred embodiment of the irrigation bath.

FIG. 2 is a sectional view taken along the - line in FIG. 1, showing the bathtub in an operating mode with the lowest flow rate.

FIG. 3 is a sectional view taken along the - line in FIG. 1, showing the bathtub in an operating mode with a high flow rate.

FIG. 4 is a cross-sectional view taken along the line - in FIG. 1, showing the gas and liquid inlet openings in the opposite end wall of the bathtub.

With reference to the drawings, the bathtub is preferably made of plastic material and has a liquid inlet manifold 1 provided with a plurality of liquid inlet openings 2 communicating with a bath cavity 3 of the bathtub. . A hole 4 in the bathtub wall communicates the liquid inlet manifold 1 with the outside, and at its outer end the hole 4 may be provided with means by which a supply of liquid can be connected to the bathtub. A typical coupling means is a threaded portion 26 or the like. Although it is contemplated within the scope of the invention that there may be only one liquid inlet opening 2, in a preferred embodiment there may be a number of spaced apart openings 2 along one or more bathtub walls. A separate fluid inlet opening 2 may be provided to ensure that minimal disturbance to the tissue specimen placed in the bath occurs while fresh fluid is flowing through the opening 2 at a high flow rate. good.

One of the bathtub walls is provided with a cut-out to obtain a substantially horizontal edge 5, and the upper surface of this wall in the cut-out forms an inclined surface sloped downward from the horizontal edge 5 to form a drain. A liquid path 6 is formed. Closing device 7
cooperates with the drainage channel 6, which can be of any shape. However, in a preferred embodiment, it is shaped like an elongated wedge. The closure device 7 has the same length as the horizontal edge 5 along its longitudinal axis, and its lower surface 7 a is formed along the slope of the drain path 6 . In a preferred embodiment, the two surfaces are machined to be substantially flat and substantially smooth.

The closure device 7 is rotatably mounted around a longitudinal axis passing through the closure device 7 itself. This axis is the horizontal edge 5
is parallel to In the preferred embodiment, the closure device 7 is attached via a pin 8 of circular cross section, the central axis of which is the same as the longitudinal axis around which the closure device 7 pivots. The pin 8 engages in a slot 9 made in the bathtub body.

The snout 10 of the closure device 7 is formed to have a semicircular cross-section, which semicircle has a radius perpendicular to the longitudinal axis around which the pin 8 is mounted, and which has an arbitrary radius of said longitudinal axis. It has a point as its center of rotation.

Furthermore, the mounting slot 9 is located at the horizontal edge 5.
and the edge of the snout 10 of the closure device 7 is the same at all points along this horizontal edge 5, so that the distance between the pin 8 and the slot associated with the snout 10 is the same at all points along this horizontal edge 5. The above-mentioned requirements for the position of 9 ensure that: That is, when the closure device 7 is rotated about its mounting axis through any angle, typically up to 30°, optimally between 5 and 15°, the gap between said two edges remains constant. It is to become. This gap is
In this preferred embodiment, typically 1
It becomes mm.

Means are provided for adjusting the rotational position of the closure device 7 about a longitudinal axis passing through the center of the mounting pin. In a preferred embodiment, this means consists of a plate 11 suitably fixed to the upper surface of the closure device 7 by means of countersunk screws 12 or similar means, and a screw pin 14 is inserted into the plate along with a screw hole 13 through which it passes. The lower end of the screw pin 14 is directly supported by the bathtub body. When the screw pin 14 is turned in the screwing direction, the closing device 7 rotates about its mounting axis in a direction away from the bathtub body. Conversely, when the screw pin 14 is turned in the counter-screwing direction, the closing device 7 is rotated in a direction toward the bathtub body.

Associated with said adjustment means are stop means. This may be any suitable arrangement, but in a preferred embodiment it is formed by the point of contact between the underside of the plate 11 and the bathtub body. The plate 11 mounted on the closure device 7 is fixed when the screw pin 14 is screwed into the outermost position of the plate 11.
The lower surface of the closing device 7 is in contact with the bathtub body, and the distance between the lower surface 7a of the closing device 7 and the slope of the drain channel 6 is such that the horizontal edge 5 and the closing device 7 and the nasal protrusion 10 (see FIG. 2).

As described above, the closure device 7 is connected to the threaded pin 14.
horizontal edge 5 and nose-like projection 10 of the closure device when rotating about its mounting axis by screwing
On the other hand, the distance between the inclined surface of the drainage channel 6 and the lower surface 7a of the closure device 7 will increase (see FIG. 3).

In connection with the preferred embodiment described above, the liquid entering the bathing cavity 3 of the bathtub via the liquid inlet opening 2 continues until the liquid contained in this cavity reaches the level of the horizontal edge 5. You will see the bathtub filling up. Furthermore, the liquid flowing into the bathtub causes the liquid already present in the bathtub to flow out over the horizontal edge 5, and the liquid thus discharged is formed between the lower surface 7a of the closing device 7 and the drain channel 6. Any further liquid present on the horizontal edge 5 will flow out through said gap 23 by the siphon effect.
Furthermore, when the adjustment means is used to rotate the closure device 7 about its mounting axis as explained above, the slope of the drainage channel 6 and the lower surface 7 of the closure device 7
The gap 23 between a becomes larger (see Figure 3),
As a result of the Bernoulli effect, the liquid present on the horizontal edge 5 is drawn downward through the drainage channel 6 at a higher speed. The liquid thus moved travels down the drain path 6 and falls into the drain reservoir 15. The floor surface of the drain reservoir is sloped so that any liquid present in the drain reservoir 15 is drained through the drain holes 16.

The preferred embodiment is the gas inlet myfold 17.
Contains. It communicates via a gas discharge opening 18 with the bathing cavity 3 of the bathtub. The gas release openings 18 are preferably substantially equally spaced along one or more walls of the bath cavity and are located at a height slightly above the level of the horizontal edge 5. There is. A hole 20 is provided in the bathtub body adjacent to the gas inlet manifold 17, said hole 20 extending across the bathtub body and opening at both ends 21 to the outside. The hole 20 may be provided at one or both ends with means to which a gas supply device (not shown) can be connected. Furthermore, a hole 19 connects the hole 20 with the gas inlet manifold 17, thus directing the gas through these holes 19, 20 to the gas inlet manifold 17.
can be supplied to The gas thus supplied is supplied into the bathtub through the gas discharge opening 18. The gas release openings 18 are spaced apart from each other so as to form a gas layer over the surface of the liquid present in the bath for the purpose explained above.

Furthermore, the preferred embodiment includes an intramural cavity 22 within the tub wall. The wall cavity 22 communicates with the bath cavity 3 at a point below the level of the horizontal edge 5. This intrawall cavity 22 typically includes a silver chloride reference electrode and a temperature sensor (not shown).
Alternatively, it can accommodate other electrodes needed for research.

Preferably, the floor of the bathtub is coated with a transparent, non-toxic, non-absorbing resin. It is then possible to hold down the pins used to locate and fix the tissue to be studied on the floor while allowing light to pass through for visual recognition of the tissue placed in the bath. Additionally, the bathtub may be equipped with a thermostatically controlled electric heating device 24 to heat the liquid and maintain it at the desired temperature. Suitable recesses 25 may be provided in the upper surface of the bathtub wall to allow the placement of electrical conductors for electrical heating devices and to facilitate the use of sintered gas bubblers or other similar devices.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a preferred embodiment of the irrigation bath. FIG. 2 is a sectional view taken along the - line in FIG. 1, showing the bathtub in an operating mode with the lowest flow rate. FIG. 3 is a sectional view taken along the same line - in FIG. 1. Figure 4 is the first
Figure 3 is a cross-sectional view along the - line in the figure showing the gas and liquid inlet openings in the opposite end wall of the bath; 1...Liquid inlet manifold, 2...Liquid inflow opening, 3...Bath cavity, 4...Hole, 5...Horizontal edge,
6... Drainage path, 7... Closing device, 7a... Lower surface,
8...Pin, 9...Slot, 10...Nose-shaped protrusion, 11...Plate, 12...Countersunk screw, 13
...screw hole, 14...screw pin, 15...drainage reservoir, 16...drainage hole, 17...gas inlet manifold, 18...gas discharge opening, 19...hole, 2
0... Hole, 21... Both ends, 22... Hole in the wall, 2
3... Between, 24... Electric heating device, 25... Recess,
26...Threaded part.

Claims (1)

[Scope of Claims] 1. A bathtub used for research on human or animal tissue preserved in vitro, comprising: a main body having a bath cavity; a means for causing a liquid to flow into the bath cavity; the means for causing liquid to flow out from the bath cavity, the means for causing liquid to flow out from the bath cavity, the means for causing liquid to flow out from the bath cavity, the means for causing liquid to flow out from the bath cavity, the means for causing liquid to flow out from the bath cavity, the liquid drainage passage formed in the wall of the bathtub, and the liquid drainage passage is arranged such that the highest liquid level in the bath cavity An irrigated bathtub comprising an upper edge which is horizontal to define, said drainage channel being provided with means for regulating the outflow of liquid from the bathtub. 2. The means for regulating the outflow of liquid from the bathtub comprises a closure device having a surface adapted to maintain a predetermined contact relationship with the drainage channel. Bathtub as described. 3. The drain path is formed to have a downward slope from the upper edge, and the closure device is formed in an elongated wedge shape, and a lower surface thereof maintains a predetermined contact relationship with the drain path. 3. A bathtub according to claim 2, which is adapted to do so. 4. The closure device has a snout and is pivotally mounted such that the closure device pivots about an axis substantially parallel to the upper edge of the drainage channel, said mounting comprising: 4. Bathtub according to claim 2 or 3, characterized in that during any rotation of the closure device, a constant distance is maintained between the nose and the upper edge. 5. A bathtub according to claim 4, wherein the closure device is provided with means allowing adjustment of its rotational position about the axis. 6. A bathtub according to any one of claims 1 to 5, wherein the bathtub includes means for allowing gas to flow over the surface of the liquid contained within the bathtub. 7. said means comprises a manifold adapted to carry out the supply of gas, and connected to said manifold and adapted to emit gas close to the surface of the liquid contained in the bath; 7. Bathtub according to claim 6, comprising at least one discharge opening. 8. Said means for allowing the inflow of liquid into the bathtub comprises a liquid manifold adapted to carry out the supply of liquid and at least one opening connected to said manifold; 8. A bathtub according to any one of claims 1 to 7, wherein the opening is formed within one or more bathtub walls below the height of the upper edge of the drainage channel. 9 The means for allowing liquid to flow into the bathtub is
9. A bathtub as claimed in claim 8, comprising a plurality of openings substantially equally spaced from each other. 10 Claims 1 to 1, wherein the bathtub is equipped with a heating device controlled by a thermostat.
The bathtub described in any one of Item 9. 11. Claims 1 to 10, wherein the bathtub is provided with an in-wall space inside the bathtub wall, and the in-wall space is adapted to accommodate a reference electrode, a temperature sensor, etc. The bathtub described in any one of the following items.