WO2007061309A2

WO2007061309A2 - Covering sheath, and an optical measuring device to use said sheath with

Info

Publication number: WO2007061309A2
Application number: PCT/NL2006/050299
Authority: WO
Inventors: Keshen Rohinder Mathura
Original assignee: Intellectual Property Mvm B.V.
Priority date: 2005-11-28
Filing date: 2006-11-28
Publication date: 2007-05-31
Also published as: NL1030539C2; WO2007061309A3

Abstract

The invention relates to a covering sheath (1) for single use and designed to be used with an optical measuring device for determining at least one bodily parameter of a person or animal, comprising a window (2) and, adjacent thereto, a substantially cylindrical sheath wall (3) that fits around a lens tube of the optical measuring device, wherein the window is located in the lens tube's field of vision, and wherein further a fastening member is provided for fixing the sheath to the lens tube, wherein near the window and inside the substantially cylindrical sheath wall, the fastening member comprises at least one protuberance (4), designed to cooperate with a groove or rim of the lens tube adapted to said protuberance.

Description

Covering sheath and an optical measuring device to use said sheath with

The invention relates to a covering sheath for single use and designed to be used with an optical measuring device for determining at least one bodily parameter, for example, a vascular parameter of a person or animal, comprising a window and, adjacent thereto, a substantially cylindrical sheath wall that fits around a lens tube of the optical measuring device, wherein the window is located in the lens tube's field of vision, and wherein further a fastening member is provided for fixing the sheath to the lens tube. The invention is further embodied in an optical measuring device for determining a bodily parameter of a person or animal, comprising a lens tube for emitting and receiving optical signals, which lens tube is designed for cooperating with a covering sheath that is provided with a win- dow and, adjacent to this window, a sheath wall.

An optical measuring device for determining a bodily parameter of a person or animal is known from the international patent application WO 2005/032361.

Such an optical measuring device is also known from the international patent application WO 97/15229 from which the use of polarising filters to be placed in the field of vision is known.

Also known is the use of a covering sheath in accordance with the preamble, which serves on the one hand to pro- tect the optical measuring device from body fluids of the person or animal to be examined, which could have a negative effect on the efficacy of the measuring device.

On the other hand, said covering sheath serves to prevent the transmission of harmful substances or viruses, and to avoid other contamination between persons or animals during subsequent use of the device.

The covering sheath to be used has to meet certain preconditions. For example, the influence on the formation by the optical measuring device of the image must be minimal. It is therefore, among other things, of importance that the po- sition of the window of the covering sheath in relation to the lens tube is crucial with regard to the precision of image formation the optical measuring device is able to provide. Owing to the dimensioning of the known optical measur- ing device the phenomenon occurs that an approximately 1 mm deviation of the window' s position in relation to the lens tube causes a distortion in the lens tube's focal plane of approximately 1 cm. It goes without saying that with such extreme sensitivity, the effect of the covering sheath's expan- sion when being used at the normal body temperature of a person or animal, can also not be ignored without detrimental effects on the precision of the image formation by the optical measuring device.

The object of the invention is to guarantee the pre- cision of the image formation by the optical measuring device, to provide for^" the same a suitable covering sheath, which even at different ambient temperatures does not cause any noticeable deterioration of the quality of the image formation of the optical measuring device and in general, to provide an alternative for the existing covering sheath that will be better able to fulfil the above mentioned objectives.

To this end the covering sheath and the optical measuring device according to the invention are characterised by one or several of the appended claims . In a first aspect of the invention the covering sheath is characterised in that near the window and inside the substantially cylindrical sheath wall the fastening member comprises at least one protuberance designed to cooperate with a groove or rim of the lens tube adapted to said protu- berance.

Correspondingly, the optical measuring device according to the invention is characterised in that the lens tube is provided with at least one groove or rim that serves for cooperating with an internal protuberance provided on the sheath wall of the covering sheath.

By means of the above-mentioned measures it is possible to position the covering sheath's window very precisely in the lens tube's field of vision, so as to guarantee a pre- cise and reliable image formation with the optical measuring device. The consequence of providing the protuberance near the window and correspondingly providing the groove or rim on the lens tube is that expansion of the material of the cover- ing sheath (for example owing to body heat and/or the temperature in the operating room) has virtually no effect on the positioning of the covering sheath's window in relation to the lens tube. Another advantage coming within reach through this measure is that the lens tube may be embodied longer, which enhances the image forming qualities of the optical measuring device and which is also useful for the manoeuvrability in various clinically relevant positions.

It is advantageous to embody the covering sheath such that there are several evenly distributed protuberances provided at the side of the sheath wall that, during use, is directed towards the lens tube. Complementarily, the optical measuring device then needs to be provided with a number of grooves or rims that match the number of protuberances of the covering sheath. By evenly distributing the protuberances, the precision of the window positioning may be enhanced further.

Another aspect of the invention relates to the measure that the protuberance, or each of the protuberances, is positioned at an end of a basal thickening extending from the protuberance or protuberances in the direction of the window.

This achieves firstly that the covering sheath, which is usually manufactured by injection moulding, can easily be removed from the injection mould without damaging the protuberances . Secondly, this measure avoids the problem that in the absence of a basal thickening, the act of placing the covering sheath on the lens tube may damage the protuberance or protuberances. At the worst, the protuberance or protuberances may even be scraped off in the absence of said basal thickening.

The favourable effect of the basal thickening just referred to is further enhanced by embodying the covering sheath such that at the side of the window, the basal thick- ening finishes as a thickening provided as an endless band on the wall of the cylindrical sheath.

Still another aspect of the invention relates to the measure that the window is made of a plastic material that is transparent for visible light, and that is resistant to sterilisation without perceptible impairment to its optical qualities.

In this way the precision and reliability of the image formation of the optical measuring device in which the covering sheath according to the invention is used is safeguarded.

It has further been shown to be favourable for the plastic material of which the window is made to be injectable. The covering sheath's window according to the invention can be suitably embodied by selecting the plastic material for the window from the group comprising PMMA, Cyrolite, Terlux, Eastar, Durastar, Altuglas.

A further advantageous aspect of the invention re- lates to the measure that the covering sheath is characterised in that the window and the sheath wall are made of the same material and are integrally formed.

It was thus shown to be possible to fabricate the covering sheath according to the invention at relatively low costs and as batch production in an injection moulding process.

The covering sheath according to the invention is in a further aspect characterised in that the window is part of a window wall adjacent to the sheath wall, and in that the window in the window wall is staggered such that the window is moved in a direction away from an open side of the sheath wall.

This measure achieves that undesirable light scattering leaving the optical measuring device or entering it, is prevented. Propagating light in the sheath wall is now unable to leave the window in a manner that could detract from the image forming qualities of the lens tube. A further favourable aspect of the invention relates to the embodiment of the covering sheath being such that at the transition to the sheath wall, the outer corner of the window wall is rounded off. This effectively avoids damage to tissue of the person or animal to be examined.

The covering sheath according to the invention is further preferably characterised in that the sheath wall is conical, having an inside diameter that increases in the di- rection of the open side of the sheath wall.

This enhances the simplicity and convenience when the covering sheath is placed on and, after use, removed from the lens tube. The conical shape also improves the removability of the covering sheath from the injection mould. It is further advantageous for the sheath wall at its open side to be provided with one or several inwardly directed ribs. This is a particularly simple manner for avoiding any play when placing the covering sheath on the lens tube. As already mentioned, the invention is also embodied in an optical measuring device for determining at least one bodily parameter of a person or animal, which device comprises a lens tube designed to co-operate with the above discussed covering sheath. For reliably positioning the covering sheath at a chosen position on the lens tube, the optical measuring device is preferably characterised in that the protuberance of the protected sheath homes in on a predetermined fixed position of the covering sheath on the lens tube. A further advantageous aspect of the optical measuring device is that the same is provided with a detection organ for the covering sheath, and in that the operationality of the device depends on this detection organ.

Another advantage of the optical measuring device according to the invention is that the same is preferably equipped with a release member for removing the covering sheath from the lens tube. The simplicity of operating the optical measuring device according to the invention is served by the detection organ and the release member being combined.

Hereinafter the invention will be further elucidated by way of an exemplary embodiment that does not limit the appended claims, and with reference to the drawing. The drawing shows in:

- Figure 1 a longitudinal cross-section of the covering sheath according to the invention, and - Figure 2 a detail of the covering sheath shown in

Figure 1.

Identical reference numerals in the figures refer to similar parts.

With reference first to Figure 1, a longitudinal cross-section is shown of the covering sheath 1 according to the invention.

After sterilisation, this covering sheath 1 is suitable to be used with an optical measuring device for determining one or several vascular parameters of a person or ani- mal. The embodiment of such an optical measuring device is well known to the person skilled in the art and requires no further elucidation.

The covering sheath 1 according to the invention serves for being placed on a lens tube of the above referred to optical measuring device and comprises to this end a window 2 and, adjacent to this window 2, a substantially cylindrical sheath wall 3 that with respect to its size, fits around the above-mentioned lens tube of the optical measuring device. It should be understood thus that when the optical covering sheath 1 is placed on the lens tube, the window 2 is located in the lens tube's field of view.

The invention will be further elucidated with reference to Figure 2, which shows a detail indicated as A in Fig- ure 1.

Figure 2 shows that near the window 2 and at the inside of the substantially cylindrical sheath wall 3, a protuberance 4 is provided. The inside of the sheath wall 3 is preferably provided with a number of such evenly distributed protuberances 4.

This protuberance 4 or protuberances 4 are designed to cooperate with a matching groove or grooves or a rim or rims provided at the outer periphery of the lens tube. How this should be realised will be obvious to the person skilled in the art, so that further elucidation may be dispensed with. Nevertheless, it may be mentioned that the groove preferably has a slanting lead surface causing the protuberance 4 of the covering sheath 1 to home in on a predetermined fixed position of the covering sheath 1 on the lens tube, as soon as the protuberance 4 reaches the slanting lead surface.

Figure 2 further shows that the protuberance 4 or the protuberances 4 are each positioned at an end of a basal thickening 5 that extends from the protuberance 4 or protuberances 4 in the direction of the window 2.

The just referred to basal thickening 5 preferably finishes as a thickening provided as an endless band 6 on the cylindrical sheath wall 3. The window 2 is preferably made of a plastic material that is transparent for visible light and resistant to repeated sterilisation without perceptible impairment to the optical qualities of this window 2. It is also advantageous for the plastic material of the window 2 to be injectable. Suitable materials that can be used for one thing and another may be selected from the group comprising PMMA, Cyrolite, Terlux, Eastar, Durastar, Altuglas.

It is further desirable for the window 2 and the sheath wall 3 to be made of the same material and to be formed integrally♦

Figure 2 clearly shows that the window 2 is part of a window wall 7 adjacent to the sheath wall 3 and that the window 2 in the window wall 7 is staggered, such that the window 2 is moved in a direction away from the open side of the sheath wall 3 indicated with arrow B.

Figure 2 further clearly shows that at the transition 8 from the sheath wall 3 to the window wall 7, the covering sheath 1 is embodied with a rounded corner. Referring again to Figure 1, it is shown that near the open side B of the sheath wall 3, said sheath wall is provided with one or several ribs 9 directed inward. Figure 1 actually only shows one such rim 9.

Figure 1 also clearly shows that the sheath wall 3 is conical, having an inside diameter that increases in the direction of the open side B of the sheath wall 3. This promotes the ease and the simplicity both of placing the covering sheath on and removing it from the lens tube.

Claims

CIAIMS

1. A covering sheath (1) for single use and designed to be used with an optical measuring device for determining at least one bodily parameter of a person or animal, comprising a window (2) and, adjacent thereto, a substantially cy- lindrical sheath wall (3) that fits around a lens tube of the optical measuring device, wherein the window (2) is located in the lens tube's field of vision, and wherein further a fastening member is provided for fixing the sheath to the lens tube, characterised in that near the window (2) and in- side the substantially cylindrical sheath wall (3) the fastening member comprises at least one protuberance (4) designed to cooperate with a groove or rim of the lens tube adapted to said protuberance.

2. A covering sheath (1) according to claim 1, ohar- acterised in that there are several evenly distributed protuberances (4) provided at the side of the sheath wall that, during use, is directed towards the lens tube.

3. A covering sheath (1) according to claim 1 or 2, characterised in that the protuberance (4) , or each of the protuberances (4), are positioned at an end of a basal thickening (5) extending from the protuberance (4) or protuberances (4) in the direction of the window (2) .

4. A covering sheath (1) according to claim 3, characterised in that at the side of the window (2) , the basal thickening (5) finishes as a thickening provided as an endless band (6) on the wall of the cylindrical sheath (3) .

5. A covering sheath (1) according to one of the preceding claims, characterised in that the window (2) is made of a plastic material that is transparent for visible light, and that is resistant to sterilisation without perceptible impairment to its optical qualities.

6. A covering sheath (1) according to claim 5, characterised in that the plastic material is injectable.

7. A covering sheath (1) according to claim 5 or 6, characterised in that the plastic material for the window is selected from the group comprising PMMA, Cyrolite, Terlux, Eastar, Durastar, Altuglas.

8. A covering sheath (1) according to one of the preceding claims, characterised in that the window (2) and the sheath wall (3) are made of the same material and are integrally formed.

9. A covering sheath (1) according to one of the claims 1-8, characterised in that that the window (2) is part of a window wall (7) adjacent to the sheath wall (3), and in that the window (2) in the window wall (7) is staggered such that the window (2) is moved in a direction away from an open side (B) of the sheath wall (3) .

10. A covering sheath (1) according to claim 9, characterised in that in the vicinity (8) of the transition to the sheath wall (3), the external corner of the window wall (7) is rounded off.

11. A covering sheath (1) according to one of the claims 1-10, characterised in that the sheath wall (3) is conical, having an inside diameter that increases in the di- rection of the open side (B) of the sheath wall (3) .

12. A covering sheath (1) according to one of the claims 1-10, characterised in that at its open side (B) , this sheath wall (3) is provided with one or several inwardly directed ribs (9) .

13. An optical measuring device for determining a bodily parameter of a person or animal, comprising a lens tube for emitting and receiving optical signals, which lens tube is designed for co-operating with a covering sheath that is provided with a window and, adjacent to this window, a sheath wall, characterised in that the lens tube is provided with at least one groove or rim that serves for cooperating with an internal protuberance provided on the sheath wall of the covering sheath.

14. An optical measuring device according to claim 13, characterised in that the groove has a slanting lead surface causing the protuberance (4) of the covering sheath (1) to home in on a predetermined fixed position of the covering sheath (1) on the lens tube.

15. An optical measuring device according to claim 13 or 14, characterised in that the same is provided with a detection organ for the covering sheath_/ and in that the op- erationality of the device depends on this detection organ.

16. An optical measuring device according to one of the claims 13-15, characterised in that the same is equipped with a release member for removing the covering sheath from the lens tube.

17. An optical measuring device according to claims 15 and 16, characterised in that the detection organ and the release member are combined.