Test Method for a Disposable

Abstract

In a method for testing a disposable on a medical examination appliance, more particularly on a tonometer, wherein the medical examination appliance comprises a disposable holding apparatus, on which a disposable is held and, in particular, able to be brought into contact with a patient's eye for an applanation tonometry measurement, and which comprises a detection device, by means of which a physical property of the disposable can be measured, a measured value of the physical property of the disposable is ascertained by means of the detection device.

Claims

1. Method for testing a disposable on a medical examination appliance, more particularly on a tonometer, wherein the medical examination appliance comprises a disposable holding apparatus, on which a disposable is held and, in particular, able to be brought into contact with a patient's eye for an applanation tonometry measurement; comprises a detection device, by means of which a physical property of the disposable can be measured; characterized in that a measured value of the physical property of the disposable is ascertained by means of the detection device.

2. Method according to claim 1, characterized in that an operating state is assigned to the medical examination appliance, in particular the tonometer, on the basis of the measured value.

3. Method according to claim 1, characterized in that the physical property comprises the natural frequency of the disposable and/or of a part of the medical examination appliance, in particular of the tonometer, comprising the disposable.

4. Method according to claim 3, characterized in that, for the purposes of ascertaining the natural frequency, the disposable and/or a part of the medical examination appliance, in particular of the tonometer, comprising the disposable are/is made to vibrate by an apparatus for generating an applanation force.

5. Method according to claim 3, characterized in that the vibration is generated electromagnetically.

6. Method according to claim 3, characterized in that at least one of the following features is determined on the basis of the measured value of the natural frequency: an alignment of the disposable on the medical examination appliance; a mass of the disposable; a mass distribution, in particular a center of mass of the disposable.

7. Method according to claim 1, characterized in that the physical property comprises an optical reflection behavior of the disposable.

8. Method according to claim 7, characterized in that the optical reflection behavior comprises an optical detection of data of the disposable.

9. Method according to claim 8, characterized in that the data of the disposable comprise a code, in particular a QR code or a barcode, wherein the code is detected with the medical examination appliance, in particular the tonometer and/or a slit lamp.

10. Method according to claim 7, characterized in that contaminations of the disposable are ascertained on the basis of the optical reflection behavior.

11. Method according to claim 6, characterized in that the optical reflection behavior is ascertained with an image sensor of the examination appliance, in particular of the tonometer, and/or a slit lamp.

12. Test body for use in a tonometer, wherein the test body comprises a contact area for contacting the cornea, characterized in that the test body comprises a code which, in particular, is detectable by a detection device of the tonometer and/or of a slit lamp.

13. Test body according to claim 12, characterized in that the contact area comprises a code, which is detectable by a detection device of the tonometer and/or of a slit lamp.

14. Test body according to claim 12, characterized in that the code is presented centrally on the contact area, in particular on an area of less than 33 mm, particularly preferably less than 22 mm, more particularly preferably on approximately 1.51.5 mm.

15. Test body according to claim 12, characterized in that the code has a circular ring-shaped embodiment and is arranged in a peripheral region with respect to the contact area.

16. Apparatus for carrying out a method according to claim 1, comprising a tonometer with a disposable-holding apparatus, characterized in that the disposable-holding apparatus comprises a ring illumination that is embodied as a stop for an edge of a cap-shaped disposable.

17. Test body according to claim 13, characterized in that the code has a circular ring-shaped embodiment and is arranged in a peripheral region with respect to the contact area.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In the drawings used to explain the exemplary embodiment:

[0067] FIG. 1 shows a schematic illustration of a side view of a tonometer head;

[0068] FIG. 2 shows an illustration according to FIG. 1 with a fitted disposable;

[0069] FIG. 3 shows an illustration according to FIG. 2, wherein the disposable is presented as a sectional image;

[0070] FIG. 4 shows a schematic side view of a slit lamp comprising a tonometer;

[0071] FIG. 5 shows a schematic plan view of a disposable with a code applied centrally to the contact area; and

[0072] FIG. 6 shows a schematic plan view of a disposable with a code applied in the edge region of the contact area.

[0073] In principle, the same parts in the figures have been provided with the same reference signs.

WAYS OF IMPLEMENTING THE INVENTION

[0074] In general, the figures explained in the following are greatly simplified. Detailed representations of optical components, in particular lens systems for magnification and focusing, filters, etc., are dispensed with deliberately since a person skilled in the art is sufficiently well aware of the structure thereof.

[0075] FIG. 1 shows a schematic illustration of a side view of a tonometer head 10. The tonometer head 10 comprises a tonometer body 11. The latter has a ring illumination 14 and a base 15 for receiving a test body embodied as a disposable.

[0076] The tonometer body 11 is guided in a longitudinally displaceable fashion in a guide apparatus 12. The guide apparatus 12 comprises an electrically actuatable coil for generating a magnetic field while the tonometer body 11 comprises a magnetic element not illustrated in any more detail. If a magnetic field is now generated in the coil, a force is applied to the tonometer body 11 in the guide apparatus 12 and said tonometer body is displaced in the longitudinal direction.

[0077] In order to be able to determine the position of the tonometer body 11 relative to the guide apparatus 12, the tonometer body 11 comprises a position sensor 13. Such sensors are known to a person skilled in the art.

[0078] FIG. 2 shows an illustration according to FIG. 1 with a fitted disposable 20. In the present case, the disposable 20 has a cap-shaped embodiment. For a better illustration, FIG. 3 additionally shows an illustration according to FIG. 2, where the disposable 20 and the guide apparatus 12 are presented as a sectional image.

[0079] The disposable 20 comprises a contact area 21, which is pressed against the cornea in the method for ascertaining an internal pressure of an eye. The contact area 21 is adjoined by a circular conical frustum sheath-shaped region 22, which merges into a circular cylinder sheath-shaped region 23. In the present case, this is produced from a clear plastic, in particular acrylic glass or PMMA (polymethylmethacrylate). Acrylic glass should be particularly preferred because it transmits light particularly well. However, it is evident to a person skilled in the art that other materials can also be used.

[0080] The tonometer head 11 comprises a base 15, on which the disposable 20 is fitted. The base 15 comprises an optical channel that completely passes through the tonometer head 11 in the longitudinal direction.

[0081] The disposable is placed on the base 15 of the tonometer body 11 and pushed as far as the stop. Consequently, the disposable is held in force-fit fashion. In the present case, the stop is formed by a ring illumination 14. Said ring illumination contacts the edge of the disposable 20 when the latter is assembled. Therewith, light can be guided from the ring illumination 14 to the contact area 21 through the sheath areas 23 and 22. If the contact area 21 is now pressed against a cornea of an eye, the area in contact with the cornea appears dark. The dark area can thereupon be measured in order to be able to test, for example according to Goldmann, whether the predetermined applanation area has been reached. During the application, the magnetic field of the coils in the guide apparatus 12 is actuated on the basis of the ascertained applanation area in such a way that the contact pressure of the disposable 20 on the cornea of the eye can be regulated. To this end, the applanation area is continuously measured by means of a detection device. Finally, the force that is required for applanation of an area of 7.35 mm.sup.2 or a circular area with a diameter of 3.06 mm is determined. The force can be calculated on the basis of the magnetic field strength. Further, the force can also be deduced using the position sensor 13 on the basis of the longitudinal displacement of the tonometer body 11 relative to the guide apparatus 12.

[0082] Now, the tonometer head can not only be moved in linear fashion but also be made to vibrate by means of the actuator, i.e., by means of the guide apparatus 12 and the tonometer head 11. The natural frequency changes according to the mass distribution of the tonometer head 11, and so whether the tonometer 10 is in an operational state can be ascertained on the basis of the natural frequency. To this end, a bandwidth of the admissible natural frequency can be predetermined. An operational state can be assigned to the tonometer when the measured value of the natural frequency lies in the bandwidth, otherwise, a warning, for example, can be output. This can prevent the disposable 20 from not being placed correctly on the base. Further, the use of unsuitable disposables can be avoided. Not least, this can prevent a measurement from being carried out entirely without a disposable.

[0083] FIG. 4 shows a schematic side view of a slit lamp 100 comprising a tonometer 10.

[0084] The slit lamp 100 comprises a tonometer arm 160, an illumination unit 110 and an optics part 120, which are assembled on a cross slide 130. The cross slide 130 itself is assembled on a base plate 140, which can be embodied as a tabletop, and can be displaced in the X-, Y- and Z-direction. The slide 130 is controllable by way of an operating element 131.

[0085] The slit lamp 100 comprises a principal pivot shaft 150, by means of which the L-shaped tonometer arm 160, the illumination unit 110 and the optics part 120 are mounted in pivotable fashion. The tonometer arm 160 comprises a tonometer 10, which can be pivoted into the beam path of the slit lamp 100 when necessary.

[0086] The illumination unit comprises an illuminant 111, which can guide light to an eye 201 of a patient 200 via a semitransparent mirror 112. The optics part 120 comprises a deflection mirror 121, by means of which entering light can be guided from the eye to an image sensor 122, both during the application as a tonometer and during the application as a slit lamp. The image sensor 122, in turn, is connected to a computer, a separate computer 170 in the present case, by means of which the image data of the image sensor 122 can be evaluated. The computer 170 is connected to a monitor 171, on which the image data of the image sensor 122 can be observed. In principle, more than one image sensor may also be provided, allowing different spectra (UV, IR, etc.) to be covered, for example.

[0087] Now, the image sensor 122 can not only ascertain the applanation area but can also check a state of the disposable 20.

[0088] In particular, an image analysis, for example, can ascertain whether the contact area is clean and free from damage such that a correct measurement of the intraocular pressure can be obtained.

[0089] Within the method, at least one image is recorded using the image sensor 122 and analyzed following the assembly of the disposable 20 on the tonometer body 11 and before the tonometric measurement is carried out. In the process, it is possible, for example, to determine whether the contact area has scratches, tears, breaks, contaminations, etc. An operating state can be assigned to the tonometer on the basis of the findings. Should the damage be too great, a warning can be output, or the tonometer can be electronically blocked such that no measurements can be carried out. Alternatively, a calibration can be carried out in the case of little damage or irregularities such that the subsequent tonometric measurement can be adjusted in relation to the damage or irregularities. A normal operating state can be assigned directly if no damage or contaminations is/are ascertained, whereupon the tonometric measurement can be carried out.

[0090] Further, the image sensor 122 can also be used to ascertain whether further parts of the tonometer 10, in particular the optical parts, have contaminations or damage. By way of example, a surface of the base 15 can be checked in respect of contaminations or damage.

[0091] In a further embodiment, a test of the correct seat and the correct type of the disposable by way of generating a vibration using the coils contained in the guide apparatus 12 and the magnetic element of the tonometer body 11 and a test of the state of the contact area of the disposable are carried out successively or simultaneously. This achieves a particularly safe method for a tonometric measurement.

[0092] FIG. 5 shows a schematic plan view of a disposable 20 with a code 25 applied centrally on the contact area 21. Here, the viewing direction is directed into the opening of the disposable 20.

[0093] In practice, the contact area 21 of the disposable 20 merely comes into contact with the cornea by way of a contact region 24 that is largely known in advance. In a method according to Goldmann, the applanation area has an area of 7.35 mm.sup.2 and is substantially circular. The region in the interior of this area is not of interest since only the contour of the area is measured for determining the area. Typically, one or more diameters are ascertained in order finally to calculate the area. The inner region of this area can now be used to print or engrave information. In the present case, a QR code 25 is now provided within the region, which QR code can be detected by the image sensor 122 and can be evaluated by means of a computing unit 170. The QR code comprises information, by means of which the disposable can be identified. In the present case, the information comprises the manufacturer, the production date, the expiry date, a batch number and a serial number. The serial number, in particular, can be used to ascertain whether the disposable is new, i.e., whether it has not yet been used for a measurement.

[0094] As a further variant, FIG. 6 shows a schematic plan view of a disposable 20 with a code 26 applied in the edge region of the contact area 21. The code 26 is disposed outside of the region of the contact area 21 that is required for the tonometric measurement. The code 26 has the form of a semicircular ring; however, it may also have the form of a circular ring that completely surrounds the code 26. In the present case, the code 26 is embodied as a circular barcode and comprises the same information as the above-described QR code 26. During the method, the code 26 is likewise recorded by the image sensor 122 and evaluated by the computer 170 such that the disposable 20 can be identified.

[0095] Further, the contact area 21 of the disposable 20 comprises a reference size 28 in the form of a line with a defined length. This can be used to calibrate the appliance.

[0096] The image sensor need not necessarily be provided by a slit lamp. The image sensor may also be comprised directly by the tonometer itself or by any other examination appliance.

[0097] The computing unit or the computer need not be embodied as an autonomous appliance but may be part of the slit lamp.

[0098] Instead of the electromagnetic actuator, a linear drive or other means for displacing the tonometer head, known to a person skilled in the art, may also be provided.

[0099] However, the disposable may also be produced from other transparent plastics, glass or the like. The disposable need not necessarily have a cap-shaped embodiment but can, for example, also have a cylindrical embodiment, in particular made of bulk material, etc. In this case, the tonometer body may also comprise a cylindrical depression instead of the base, it being possible to insert the disposable in said depression. The disposable need not necessarily be held in force-fit fashion; instead, it may also be held in interlocking fashion or in interlocking and force-fit fashion. To this end, a person skilled in the art knows of any number of options, such as, for example, a bayonet closure, screw closure, etc.

[0100] In conclusion, it should be noted that, according to the invention, a method for testing a disposable is developed, by means of which a medical examination method, in particular a tonometric measurement method, is able to be carried out in a safer and more robust manner.