WO1997010750A1

WO1997010750A1 - Patient examination table

Info

Publication number: WO1997010750A1
Application number: PCT/IB1996/000923
Authority: WO
Inventors: Adrianus Van Der Ende
Original assignee: Philips Electronics N.V.; Philips Norden Ab
Priority date: 1995-09-22
Filing date: 1996-09-11
Publication date: 1997-03-27

Abstract

A patient examination table which is adjustable in the vertical direction and which is also tiltable. In order to realize a construction which involves slight elastic deformation only and requires a minimum floor surface, the table top is connected, via an intermediate piece, to a stand which is rigidly connected to the environment. The intermediate piece is hinged relative to the stand as well as to the table top. Between the stand and the intermediate piece and between the intermediate piece and the table top there are provided respective linear actuators for driving the hinge motion of the intermediate piece and the table top. A large range of desired orientations and positions of the table top can be realized by individual excitation of said actuators, and nevertheless, only a limited floor surface is required.

Description

Patient examination table.

The invention relates to a patient examination table as disclosed in the introductory part of Claim 1.

An examination table of this kind is known from European Patent 0 490 107. The cited Patent discloses an examination table whose stand is secured to the ceiling of the examination room, the remainder of the examination table being suspended therefrom. The table top of the examination table described in the cited document can be adjusted relative to the stand in respect of height as well as direction. The means for height adjustment of the known examination table are formed by an arm which vertically projects from the stand and which can be vertically slid in and out relative to the part of the stand which is secured to the ceiling and which is rigid in the vertical direction. Said arm supports the table top and also supports an assembly of gearwheels and a drive motor which are accommodated in a gearbox, thus constituting the means for adjusting the direction of the table top. The gearbox is secured between an end of the table top and the arm for height adjustment. The arm for height adjustment is secured to an ingoing shaft of the gearbox and the table top is secured to an outgoing shaft of the gearbox. The direction of the table top is adjusted by activation of the motor. Because of the location of the combination formed by the motor and the gearbox, the arm for height adjustment of the stand is loaded not only by the weight of the patient to be examined, but also by the weight of the combination formed by the motor and the gearbox, so that the supporting construction must be substantially heavier. Furthermore, the loading causes torsion in the shafts and the gearwheels of the adjusting means so that, in combination with the location at one end, major elastic deformation may occur in the assembly, leading to ambiguity as regards the position of the patient. This is particularly disadvantageous when use is made of examination equipment such as X-ray sources and X- ray detectors. It would be feasible to solve the problem posed by elastic deformation by utilizing a construction supporting the table top in a number of locations, but such constructions generally require a substantial amount of space in the direct vicinity of the table top, so that the freedom of movement of the attending staff around the table top is substantially restricted.

It is an object of the invention to provide a patient examination table which has a high degree of structural rigidity and requires a small ceiling or floor area.

To this end, the patient table in accordance with the invention is characterized in that the means for adjusting the table top are constructed as disclosed in Claim 1.

A support for the table top may be constructed in the form of a U, one limb of which is retained, in the vicinity of its center, on the one side by a hinged joint which constitutes the connection with the intermediate piece and on the other side by the point of application of the second actuator. The table top is then attached to the other limb of the U shape, offering ample freedom of movement to the attending staff. For some applications, however, it is also possible to mount the table top directly on a beam-like support. Because the designer is free to arrange the first linear actuator within the stand in a substantially vertical position, the floor area of the stand may remain limited. The second linear actuator may be situated directly underneath the support, so that, neither in the horizontal nor in the vertical position this actuator requires space at the expense of the free floor surface.

In a preferred embodiment of the examination table in accordance with the invention the first actuator and the second actuator act on the same point of the intermediate piece. As a result, only one point of attachment is required on the intermediate piece for the two actuators.

In another embodiment of the examination table in accordance with the invention, at least one of the actuators comprises a transducer for converting the excursion of the actuator into a measured signal. If the table is adjusted by means of a motor drive, the height and the position of the table top can thus be allowed to reach a desired value, the adjusting process being controlled by the apparatus itself.

A further embodiment of the examination table in accordance with the invention comprises processor means for controlling the excursion of the actuator in dependence on the measured signal from the transducer. By storing the actuator settings required for the various positions of the table top in a memory, the user of the examination 3 table can simply have a variety of preprogrammed displacements executed, for example adjustment of the table top to it vertical position, vertical displacement of the table top during which it remains horizontal, or tilting during which the table top is lifted over, for example an X-ray source, so that the tilting table top does not collide with the X-ray source.

The invention will be described in detail hereinafter with reference to the Figures, in which corresponding reference numerals denote corresponding elements. Therein: Fig. 1 is a perspective view of an examination table in accordance with the invention;

Fig. 2 shows the principle of the construction for adjusting the examination table;

Figs. 3a to 3d illustrate various positions of the table top of the examination table in accordance with the invention and also show the associated actuator settings.

Fig. 1 is a perspective view of a patient examination table in accordance with the invention which is arranged in an examination room. The patient examination table consists of a table top 24 for supporting the patient to be examined, a support 6 for supporting the table top 24, and a stand 2 for carrying the support. There may also be provided examination equipment such as a C-arm 26 with an X-ray source 28 and an X-ray detector 30. A practical examination table should be adjustable in respect of height and be tiltable about an axis which is preferably situated in the plane of the C-arm. An additional condition imposed on the motion of the table top is that it should not collide with the X-ray source or the X-ray detector during tilting and/or height adjustment, i.e. that it can be lifted over the source or detector. Moreover, in order to provide a maximum freedom of movement for the attending staff the stand should occupy an as small as possible floor surface. Thus, the adjustment of the examination table necessitates the use of a compact movement mechanism enabling the above motions.

Fig. 2 illustrates the principle of the movement mechanism for adjusting the examination table in accordance with the invention. A stand 2 for supporting the further parts of the examination table is arranged on a floor 16 of an examination room. Even though the stand of the examination table is arranged on the floor in this Figure and further Figures, the stand may alternatively be mounted on the ceiling of the examination room. This is irrelevant to the principle of the invention.

An intermediate piece 4 is connected to the stand 2 via a hinged joint 20. The hinge 20 enables rotary movement of the intermediate piece 4 in die plane of drawing relative to the stand 2. The intermediate piece 4 is also connected to the stand 2 via a first linear actuator 8. The actuator is connected to the stand 2 by way of a shaft 10 and to the intermediate piece 4 by way of a shaft 12a, said shafts extending perpendicularly to the plane of drawing. The actuator drives the pivoting motion of the intermediate piece relative to the stand by extension or compression. The actuator can be constructed in a variety of known ways, for example as a hydraulic system consisting of a cylinder accommodating a movable piston, or as a threaded spindle which runs in a stationary nut and is driven by an electric motor. These known constructions are not shown in detail in the Figures.

A support 6 is connected to the intermediate piece 4 via a hinged joint 22. The hinge 22 enables rotary motion of the support 6 in the plane of drawing relative to the intermediate piece 4. The support 6 is also connected to the intermediate piece 4 via a second linear actuator 14. The actuator is connected to the intermediate piece 4 by way of a shaft 12b and to the support 6 by way of a shaft 18, both shafts extending perpendicularly to the plane of drawing. The actuator drives the hinging motion of the support relative to the intermediate piece by extension or compression. This actuator may be constructed in the same ways as the first actuator 8.

Even though Fig. 2 shows the stand, the intermediate piece and the support as plane elements, these elements are of course constructed so as to be three dimensional in practice. The stand 2 may be shaped as a box, the shafts 10 and 20 then projecting through the side walls and extending perpendicularly thereto. The intermediate piece 4 is then shaped as two parallel plates which are situated within the box, directly adjacent its side walls, and are interconnected by way of an connection piece, for example in the form of a tubular part (not shown in Fig. 2) whose axis extends perpendicularly to the plates. The shaft 20 then extends through both plates and through the adjacent side walls of the box. The shaft 12a then extends only through the two plates. The support (or the part of the U-shaped support situated at the area of the stand) has the shape of a U-profile when viewed in a vertical cross-section perpendicular to the plane of drawing; the limbs of said U- profile (the side walls of the profile) are situated outside the intermediate piece and the box- shaped stand. The shaft 22 then extends through the two plates of the intermediate piece as well as through the two side walls of the profile. The shaft 12b then extends only through the two plates of the intermediate piece, and the shaft 18 extends only through the two side walls of the profile.

The excursion of the actuators can be translated into an electric signal to enable processor control of the examination table. In the case of a spindle-like actuator this can be realized by coupling the spindle, via a reducer or not, to a rotary potentiometer (not shown) having, for example ten turns. The number of rotations of the threaded spindle (i.e. the excursion of the actuator) is thus translated into a resistance value which can be readily measured electrically.

Figs. 3a to 3d show various positions of me table top of the examination table and the associated settings of the actuators. In these Figures the actuators are diagrammatically represented by a straight line.

In the Figs. 3a to 3d the fixed stand 2 arranged on the floor 16 is connected to the intermediate piece 4 via the hinge 20 and d e support 6 is connected to tiie intermediate piece 4 via the hinge 22. The actuator 8 is connected to the stand 2 via the shaft 10 and to the intermediate piece 4 via the shaft 12. The actuator 14 is connected to the intermediate piece 4 via the shaft 12 and to the support 6 via the shaft 18. In these Figures, therefore, the actuators 8 and 14 both act on the same point 12 of the intermediate piece 4. Fig. 3a shows the horizontal orientation in the lowest position of the table top. With this orientation and position the actuator 8 is fully compressed as is the actuator 14. In Fig. 3b the table top has been rotated clock-wise to a completely vertical position. The actuator 8 is then fully extended and the actuator 14 fully compressed. In Fig.

3c the table top has been rotated counterclock-wise to a completely vertical position. The actuator 8 is then fully compressed and the actuator 14 fully extended. In Fig. 3d the table top has been lifted relative to the situation shown in Fig. 3a; in comparison with the latter Figure, the actuator 8 is slightly extended as is the actuator 14.

Claims

oCLAIMS:

1. A patient examination table, comprising:

* a table top for supporting the patient to be examined,

* a stand for supporting the table top, and

* means for adjusting the height and the direction of the table top relative to the stand, characterized in that the means for adjusting the table top comprise:

* an intermediate piece which is hinged relative to the stand as well as to the table top and constitutes a coupling between the stand and the table top, * a first linear actuator which is arranged between the stand and the intermediate piece in order to drive the hinge movement of the intermediate piece relative to the stand, and

* a second linear actuator which is arranged between the intermediate piece and the table top in order to drive the hinge movement of the table top relative to the intermediate piece.

2. A patient examination table as claimed in Claim 1, in which the first actuator and the second actuator act on the same shaft through the intermediate piece.

3. A patient examination table as claimed in Claim 1 or 2, in which at least one of the actuators comprises a transducer for translating the excursion of the actuator into a measured signal.

4. A patient examination table as claimed in Claim 3, comprising processor means for controlling the excursion of the actuator in dependence on the measured signal from the transducer.