Transporter For Conveying Large Living Organisms Under Substantially Sterile Conditions

Abstract

A transporter for conveying large living organisms under substantially sterile conditions, with a space provided with air conditioning equipment wherein four of the walls of the space are formed by the inner wall of a horizontal collecting-box mounted over one or more fans and the driving gear(s) of the airconditioning equipment, by the inner walls of two channels, inclining upwards at the ends of the collecting-box and by the bottom wall of a horizontal distributing-box that is connected to the channels and in which bottom wall hepa filters are mounted. Mounted in the space is a carrying-plate that is horizontally slidable to the outside on guides, a folding bellows that is mounted between the carrying-plate and the fixed backwall of the space and under the front edge of the carrying-plate, which is bent downwards, a hinging apron that is suspended and that upon sliding out of the carrying-plate is brought into a position in which the backside of the apron is directed to the guides by cams mounted on the frame of the transporter.

Description

BACKGROUND OF THE INVENTION

The invention relates to an improvement upon a transporter for conveying large living organisms under substantially sterile conditions, in particular a germfree stretcher for patients whose condition is serious, with a space provided with an air conditioning equipment according to the principle of laminar flow that during conveyance is operating on a power source of its own such as has been described in copending U.S. Pat. application by Van der Waaij et al., Ser. No. 124,767, for "A Transporter for Substantially Germfree Transport of Big Living Organisms," filed Mar. 16th, 1971, and owned by the same assignee. In the transporter four of the walls of the space are formed by the inner-wall of a horizontal collecting-box situated over one or more fans and their driving gear(s), the inner-walls of two channels, inclining upwards, at the ends of the collecting-box and by the bottom wall of a horizontal distributing-box that is connected to the channels and in which bottom wall hepa filters (high efficiency particulate air filters) are mounted. At the back the space is provided with a closed transparent wall and at the front it has a closure that can be opened. In the back wall in a flexible plastic screen sleeves with gloves are provided for handling the patient upon bringing him in and taking him out of the transporter.

SUMMARY OF THE INVENTION

The improvement according to the invention now comprises a carrying-plate which is disposed in the aforenoted space and which is mounted horizontally slidable to the outside on guides and an air stream that from that space continues to flow over the carrying-plate at a rate high enough to guarantee that the carrying-plate and a patient lying on it are kept sterile. The bottom side of the slidable carrying-plate and the guides cannot be sterilized, however, and must be screened such that no particle of dust or bacterium from those parts can come into contact with the sterile air. Therefore, according to the invention a folding bellows is mounted between the carrying-plate and the back wall of the space. Under the front edge of the carrying-plate that is bent downwards, a hinging apron is suspended that, upon sliding out the carrying-plate, is brought into a position in which the back side of the apron is directed to the guides, by cams mounted on the frame of the transporter. The apron is so long that in the farthest slid-out position of the carrying-plate the lower edge of the apron is still situated under the horizontal collecting-box. Because of this construction it is impossible that particles of dust or bacteria from under the carrying-plate or the guides fall on the sterile floor of an operating-room, or arrive at the space over the carrying-plate.

Preferably, according to the invention at the front of the transporter the opening of the space over the carrying-plate and the gap in front of the apron both can be closed by parted lids hinging around horizontal shafts and to be opened when the carrying-plate is to be slid out, and at the upper side under the hepa filter a shield is mounted that is directed slantingly downwards and that directs a part of the air stream under the lower edge of the opened upper lid such that vortexes that might arise under the lower edge are carried off outside the space. Preferably, the transporter is constructed with an upper lid in front of the opening and a lower lid in front of the apron, which is hanging down. The lids each consist of two parts mutually connected by hinges that are connected by means of hinges to the front of the transporter in such a way that upon opening the planes of those parts that are turned towards the space are swung against each other and thus no contamination with particles of dust or bacteria can take place.

BRIEF DESCRIPTION OF THE DRAWING

The invention is described in detail below with reference to a drawing of a preferred embodiment of a transporter according to the invention drawn in cross-section with slid-in carrying-plate and partially opened space.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Frame 1 of the device is carried on four swivel wheels 2 and supports at standard height a carrying-plate 3. At the bottom of frame 1 a fan 7 is mounted from which the pre-filtered air is led into a horizontal collecting-box 11 and via head walls 13, constructed as flat channels, is carried to a horizontal distributing-chamber 14 over carrying-plate 3. Th bottom of distributing-chamber 14 for the greater part is formed by hepa filters 15 and the air thus rendered germfree flows in a laminar flow that is directed vertically downwards into space 16 over carrying-plate 3. The back wall of space 16 is formed by wall 17, in which flexible rubber gloves with sleeves may be mounted (not shown) and by a transparent window 21 arranged in an inclined position. This window 21 has been placed in an inclined position so as to have a better view of the patient but also to serve as a guiding screen to ensure that the air egressing from filters 15 does not start whirling in a dead corner. At the other side of space 16 under filters 15 another small shield 22 is mounted, which has an inclined position and is directed outwards and whose operation will be described later.

Over collecting-box 11 a supporting construction is mounted consisting of girders 23 and a plate 24 onto which brackets 25 are fitted, which support guiding bars 26, which, with supporting brackets 27, are mounted under carrying-plate 3. In this way carrying-plate 3 can be slid to the outside over plate 24 by sliding bars 26 through brackets 25 until it partially protrudes beyond space 16. At back side 28, which is flanged upwards from the carrying-plate 3, a folding bellows 29 is attached whose farther end is attached to wall 17. Thus, between carrying-plate 3 and back wall 17 a sealed but flexible connection is effected that can slide on plate 24.

At the short sides of carrying-plate 3 there are provided upwardly directed flanges 30, which can move closely past the innerwalls of channels 13 and which are also connected to front edge 20 of carrying-plate 3, which is bent downwards with a rounded corner. In carrying-plate 3, which is shaped into a trough, a mattress 31 is provided on which a patient can be laid down.

Under front edge 20 an apron 32 is suspended hingingly. In frame 1 cams 33 are fitted, which ensure that upon sliding-out of carrying-plate 3 apron 32 is tilted and its back side is turned towards guiding bars 26. Apron 32 is of such a length measured from its point of suspension that in the farthest slid-out position of carrying-plate 3 the lower edge of the apron still lies within the frame under collecting-box 11.

As a result of mounting folding bellows 29 and suspended apron 32 it is impossible for particles of dust or bacteria that are under carrying-plate 3 or on the guiding mechanisms to enter space 16 or to fall on a sterile floor upon sliding in and out the carrying-plate. Because the dustfree and germfree air emitted by filters 15 is supplied at a velocity that is higher than 0.45 m/sec, in space 16 an excess pressure arises so that in the slits between the walls and flanges 30 bacteria cannot pass into space 16. They will always be carried downwards in an air flow.

In the position shown, the carrying-pate 3 is entirely slid-in, the folding bellows 29 is folded together and apron 32 is suspended vertically downwards. So as to be able to slide the carrying-plate out, it is not only necessary that space 16 can be opened but apron 32 must also have room for its tilting movement. Therefore, in front of apron 32 a lower lid is mounted. The latter consists of a plate 34 hingingly attached to frame 1 and a plate 35 again hingingly connected to plate 34. This form is chosen because when being opened, the surface of plates 34 and 35 that are turned towards apron 32 contact each other and cannot be contaminated by the outside atmosphere. Space 16 is furthermore closed with an upper lid that is similar to the lower lid and which consists of plate 36 hingingly attached to distributing-chamber 14, and plate 37 hingingly suspended to the former. The plate 37 carries an overlap 38, which, when the transporter is closed, overlaps the upper edge of plate 35 of the lower lid.

When a patient has to be taken out of space 16, carrying-plate 3 can be drawn to the outside by means of grips 39 but first the upper lid and lower lid have to be opened. For this purpose on the upper lid a grip 40 has been mounted and on the lower lid a grip 41. For the sake of clarity the locks at the sides that are present on both lids and keep the latter closely pressed against frame 1 are not shown. When the locks are released, the upper lid is opened with grip 40 and at the same time the supply of air from the filters is increased in order to prevent the air loaded with particles of dust or bacteria from entering space 16. Inclined partition 22 under filters 15 is mounted in order to ensure that a small part of the air from filters 15 flows to the outside over partition 22 and thus prevents a vortex that might arise below overlap 38 from being drawn into space 16 by induction flow. As soon as the upper lid is opened the flow pattern of the air from filters 15 changes in such a manner that the flow does not disappear any longer downwards in the gap between front edge 20, apron 32 and the lower lid but now flows freely out to the front over the patient lying on mattress 31. Then the lower lid is opened with grip 41 and only now can the carrying-plate 3 be slid out. Apron 32, which is suspended from front edge 20 is carried along to the outside but slides over cams 33 and tilts into an inclined position so that the guiding mechanism lying over it is enclosed and in the farthest slid-out position of carrying-plate 3 the lower edge of apron 32 is still situated within frame 1 under collecting-box 11. Consequently, no particle of dust or bacterium out of the guiding mechanism can fall on the floor.

In the device according to the invention measurements have been carried out in which for an of opened upper-lid and slid-in carrying-plate the air velocity in the plane of the opening of space 16 was measured. Immediately over mattress 31 outwardly directed velocities between 0.85 and 0.93 m/sec were measured whereas at mid-height of the opening a velocity between 0.58 and 0.83 m/sec occurred. Immediately under overlap 38 velocities of 0.20 to 0.61 m/sec were measured. At any rate at the critical height of the patient a velocity was reached that makes it impossible for particles of dust and bacteria to enter space 16.

With carrying-plate 3 in completely slid-out position measurements were effected in the same places and at the same heights in a vertical plane through front edge 20 parallel to the opening. In the plane over the opening over the mattress a velocity of 0.89 to 1.07 m/sec was measured, at mid-height a velocity of 0.85 to 1.04 m/sec and under overlap 38 a velocity of 0.21 to 0.60 m/sec. In the plane through the slid-out front edge the velocities over the mattress were 1.03 to 1.06 m/sec, at mid-height 0.22 to 0.92 and at the height of the overlap 0.09 to 0.19 m/sec. It thus has been found that the position of the patient on the mattress under all conditions is such that a flow of air egressing from space 16 flows over it with a velocity greater than the 0.45 m/sec that is generally assumed as a limit above which it is impossible for particles of dust or bacteria to move against the flow.

Claims

I claim:

1. A transporter for conveying a large living organism under substantially sterile conditions, in particular a germ free stretcher for patients in serious condition, comprising

a. top, bottom, rear and side walls defining a space for accommodating said organism; said space having, opposite said rear wall, a front side through which said organism is movable into and out of said space;

b. fan means mounted on said transporter externally of said space for generating an air stream;

c. means for filtering the air in said air stream;

d. means for directing said filtered air stream through said top wall in a laminar flow across said space;

e. a horizontally disposed carrying plate having a front edge and a rear edge; said carrying plate extending substantially coextensively with and adjacent to said bottom wall;

f. guide means for horizontally slidably supporting said carrying plate, whereby the latter is movable into and at least partially out of said space through the front side thereof; and

g. a folding bellows mounted between and attached to said rear wall and the rear edge of said carrying plate.

2. A transporter for conveying a large living organism under substantially sterile conditions, in particular a germ free stretcher for patients in serious condition, comprising

a. top, bottom, rear and side walls defining a space for accommodating said organism; said space having, opposite said rear wall, a front side through which said organism is movable into and out of said space;

b. fan means mounted on said transporter externally of said space for generating an air stream;

c. means for filtering the air in said air stream;

d. means for directing said filtered air stream through said top wall in a laminar flow across said space;

e. a horizontally disposed carrying plate having a front edge and a rear edge; said carrying plate extending substantially coextensively with and adjacent to said bottom wall;

f. guide means for horizontally slidably supporting said carrying plate, whereby the latter is movable into and at least partially out of said space through the front side thereof;

g. a downwardly projecting portion forming part of said carrying plate and extending from said front edge thereof;

h. an apron hingedly suspended from said downwardly projecting portion; said apron having a front side, an opposite back side and a free lower edge; and

i. cam means positioned adjacent said front side of said apron, whereby upon sliding out said carrying plate said apron swings inwardly with respect to said transporter and is brought into a position in which said back side of said apron is oriented towards said guide means.

3. A transporter as defined in claim 2, further including a horizontally extending collecting box disposed beneath said carrying plate externally of said space, said collecting box communicating with said fan means; the free lower edge of said apron bing positioned beneath said collecting box in any slid-out position of said carrying plate.

4. A transporter as defined in claim 2, further including movable lid means adapted to assume an open position and a closed position; said lid means, in said closed position, closing said front side of said space and a gap adjacent the front side of said apron when said carrying plate is in an entirely slid-in position.

5. A transporter as defined in claim 4, further including means for hingedly securing said lids to said transporter.

6. A transporter as defined in claim 5, wherein said lids are swingable towards and away from one another about horizontal axes.

7. A transporter as defined in claim 6, including a shield disposed immediately beneath said top wall and oriented downward at an inclination, whereby part of the air in said air stream is directed from under a lower edge of said lid means in said closed position so that vortexes generated under said lower edge are expelled out of said space.