Title of Invention	APPARATUS FOR CAPTURING AN IMAGE
Abstract	Abstract APPARATUS FOR CAPTURING AN IMAGE An apparatus (1) for capturing an image of a sample retained by a sample acquiring device (7). comprises an image capturing unit (2) comprising a lens arrangement (6) with a fixed focal plane, a sample holder (3) comprising a tlrsi magnet unit (10), and a second magnet unit (14). The sample holder (3) is adapted to receive the sample acquiring device (7) and is movable in relation to the lens arrangement (6) to a first position (18). The sample holder (3) is movable from the first position (18) to a second position (19) by means of magnetic interaction of the first magnet unit (10) and the second magnet unit (14), and the image capturing unit (2) is adapted to capture an image of the sample by means of the lens arrangement (6) when the sample holder (3 is in the second position (19).

Title of Invention

APPARATUS FOR CAPTURING AN IMAGE

Abstract

Abstract APPARATUS FOR CAPTURING AN IMAGE An apparatus (1) for capturing an image of a sample retained by a sample acquiring device (7). comprises an image capturing unit (2) comprising a lens arrangement (6) with a fixed focal plane, a sample holder (3) comprising a tlrsi magnet unit (10), and a second magnet unit (14). The sample holder (3) is adapted to receive the sample acquiring device (7) and is movable in relation to the lens arrangement (6) to a first position (18). The sample holder (3) is movable from the first position (18) to a second position (19) by means of magnetic interaction of the first magnet unit (10) and the second magnet unit (14), and the image capturing unit (2) is adapted to capture an image of the sample by means of the lens arrangement (6) when the sample holder (3 is in the second position (19).

Full Text	APPARATUS FOR CAPTURING AN IMAGE Field of the Invention The present invention relates to an apparatus and a method for caoturing an image of a sample retained by a sample acquiring devjc-s. Background Art The apparatus and the method described by Way of introduction are used to capture an image of a sample for analysing the sample. PCT/SE2006/000311 (not public at filing of this application) and US 6,710,879 disclose methods for analysing a volume of a sample by processing an image of the sample. To capture an image of the sample, the sample is in some cases placed under a tens arrangement with either an adjustable focal plane or a lens arrangement with a fixed focal plane. The problems with the lens arrangements with an adjustable focal plane are that they are expensive and it is difficult to adjust the focal plane of the lens arrangement to a correct position in relation to the sample. The problems with the lens arrangements with a fixed focal plane are that the sample, for instance retained in a cuvette, has to be located in the exact same relation to the fixed focal plane of the lens arrangement each .time an image is captured to obtain a reliable result. An object of the present invention is to provide an apparatus that can capture an image of a sample retained in a sample acquiring device in a more effective way. Summary of the Invention The present invention is new and inventive by providing an apparatus according to claim 1 and a method according to claim 15. Embodiments of the invention are described in the dependent claims. The inventive apparatus for capturing an image of a sample retained by a sample acquiring device, comprises an image capturing unit comprising a lens arrangement with a fixed focal plane, a sample holder comprising a first magnet unit, and a second magnet unit, the sample holder being adapted to receive the sample acquiring device and being movable in relation to the lens arrangsment to a first position, in whicri rirst position me rirsr ana tne seoona magnet unit are arranged in such close relation that they may magnetically interact, the sample holder being movable from the first position to a second position by means of magnetic interaction of the first magnet unit and the second magnet unit, and the image capturing unit being adapted to capture an image of the sample by means of the lens arrangement when the sample holder is in the second position This provides the advantage that the sample holder can be arranged in the second position with high accuracy and that a lens arrangement with a fixed focal point can be used to capture a reliable image of a sample. This also provides the advantages that the number of moving mechanical parts for moving the sample holder from the first position to the second position is reduced. By reducing the number of moving mechanical parts an advantage is obtained in that the influence of the tolerances of each part is reduced. This is particularly advantageous when the sample acquiring device provides a sample thickness equal or marginally smaller than a depth of field of the image capturing unit. In such cases, a slight malpositioning of the sample acquiring device would render analysis of the captured image impossible or, worse, would render incorrect results of the analysis. A further advantage is that by moving the sample holder by means of magnetic interaction, the wear of the apparatus is reduced. To introduce a sample acquiring device in an easy and reliable way the apparatus can further comprise an inlet station, the sample hoidei Leiuy adapted to receive said sample acquiring device in said inlet station. To achieve the advantages of positioning the sample holder in a reliable, easy and exact position the apparatus can further comprise a third magnet unit, the third magnet unit being adapted to position the sample holder in the inlet station by means of magnetic interaction of the first magnet unit and the third magnet unit. A further advantage is that the sample holder is easy to remove from the apparatus for cleaning. The apparatus can further comprise a transfer unit, the transfer unit being arranged to support the sample holder and to transfer said sample holder from the inlet station to the first position. This leads to the advantages that the sample holder can be transferred in an easy, reliable and correct way. The transfer unit of the apparatus can be movable between the inlet station and a position in which the sampis holder is positioned in the first position. To achieve the advantages of increasing the reliability of the apparatus, the second magnet unit of the apparatus can be arranged on the transfer unit. To increase the reliability of the apparatus and to support the sample holder Vi/hen it is moved fron-. the inlet station to ihe first position the third magnet unit of the apparatus can be arranged on the transfer unit, To reduce the tolerance with which the sample holder is positioned in the second position the apparatus can further comphse an alignment means for aligning the sample holder in relation to the lens arrangement when it is moved from the first to the second position. The alignment means of the apparatus can be arranged on the transfer unit. The first and the second magnet unit of the apparatus can be arranged to move the sample holder from the first position to the second position Dy means of repellent magnetic forces. This leads to the advantages that the sample holder is arranged in the second position with a very high tolerance. To achieve the advantages of the sample holder being maintained in an correct position when it is moved the first and the third magnet unit of the apparatus can be arranged to position the sample holder in the inlet station by means of attracting magnetic forces. The sample holder of the apparatus can be adapted to receive a sample acquiring device in the form of a cuvette. The apparatus can further comprise an image processing unit, the image processing unit being adapted to process an image of the sample. The image processing unit of the apparatus can be adapted to identify and count particles in the sample, in particular, the image processing unit may be adapted to identify and count biological particles, such as blood cells, in a liquid sample, such as blood. The inventive method for capturing an image of a sample retained by a sample acquiring device, comprises: positioning the sample acquiring device in a sample holder comprising a first magnet unit, transferring said sample holder in relation to a lens arrangement with a fixed focal plane of an image capturing unit to a first position in which first position the first and a second magnet unit are arranged in such close relation that they may magnetically interact, moving the sample holder from the first position to a second position by means of magnetic interaction of the first n-iagnet unit and the second magnet unit, and capture an image of the sample by means of the lens arrangement when the sample holder is in the second position. Advantages of the Inventive method are that an image of a sample can be captured in a reliable and easy way. The method can further comprise processing said image in an image processing unrt and to identify and count partic'es in tlie sarr.pie. Brief Description of the Drawings The invention and its many advantages will be described in more detail below with reference to the accompanying schematic drawings, which for the purpose of illustration show some non-iimiting embodiments and in which Fig. 1 shows a plan view of an embodiment of the invention when the sample holder is arranged in the inlet station. Fig. 2 shows a partial cross-sectional view of the embodiment in Fig. 1 along A-A. Fig, 3 shows a plan view of an embodiment of the invention when the sample holder Is arranged in the second position. Fig. 4 shows a partial cross-sectional view of the embodiment in Fig. 3 along B-B. Fig. 5 shows a perspective view of a second embodiment of the invention All figures are highly schematic, not necessarily to scale, and they show only parts, which are necessary in order to elucidate the invention, other parts being omitted or merely suggested. Description of Preferred Embodiments Fig. 1 and 2 show an embodiment of an apparatus according to the invention. The apparatus 1 comprises an image capturing unit 2, a sample holder 3, a transfer unit 4 and an inlet station 5. In the shown embodiment, the sample holder 3 has received a sample acquiring device 7, in the form of a cuvette 7. The image capturing unit 2 comprises a lens arrangement 6 with a fixed focal plane. In the shown embodiment the lens arrangement 6 comprises four lenses 8, se Fig. 4. The sample holder 3 comprises a plate 9 and a first magnet unit 10, The plate 9 comprises a central depression 11 on an upper side and a flange 12 that is arranged on the circumference of a lower side of the piate 9 and that extends in a direction away from the upper side. The first magnet unit 10 is mounted on the lower side of the plate 9. The central depression 11 has a shape that corresponds to the shape of the sam.ple acquiring device 7- The transfer unit 4 comprises a support plate 13. a second magnet unit 14, a third magnet unit 15 and a handle 16, The support plate 13 is curved in the direction of its length. The suoport ptate 13 comprises a depression 17 on the upper side, the shape of tiie depression ' 7 corresponds tc the shape of the sample holder 3. The second magnet unit 14 and the third magnet unit 15 are mounted on the lower side of the support plate 13. The handle 16 is mounted on the side of the support plate 13, which has the largest radius. The support plate 13 of the transfer unit 4 is movable by movement of the handle 16. The sample holder 4 is arranged in the depression 17 of the support plate 13. As the support plate 13 ofthe transfer unit 4 is moved by turning the handle 16 the sample holder 3 moves together with support plate 13 of the transfer unit 4. The handle 16 ofthe transfer unit 4 is arranged to move the sample holder 3 between the inlet station 5 and a first position 18. The first and third magnet unit 10, 15 are magnets being arranged with attracting magnetic poles facing each other. The first and the second magnet units 10, 14 are magnets being arranged with repeflent magnetic poles facing each other. The third magnet unit 15 is mounted on the support plate 13 in a position such that, when the samp/e holder 3 is arranged in the inlet station 5, the first and the third magnet unit 10, 15 interacts and presses the sample holder 3 against the support plate 13. To move the sample holdai' 5 io liia iiii.[ position the handle 16 of the transfer unit 4 first is turned 75 degrees, and thereby also moving the sample holder 3. After being turned 75 degrees the sample holder 3 hits an abutment (not shown). The handle 16 of transfer unit 4 is thereafter turned another 15 degrees. By doing this the support piate 13 of the transfer unit 4 is moved in relation to the sample holder 3, such that the second magnet unit 14 is aligned vi/ith the first magnet unit 10. The sample holder 3 is now in its first position 18. To move the sample holder 3 to a second position 19 the first and the second magnet unit 10, 14 interact, see fig 3 and 4. As the first and second magnet units 10, 14 are arranged with repellent magnetic poles facing each other, the sample holder 3 will be moved upwards. The flanges 12 and an alignment means 20 of the support plate 13 interact when the sample holder 3 is moved upwards to guide the movement of and align the sample holder 3 with an optical axis of the lens arrangement 5, The alignment means 20 can be constituted of the walls 20 of the depression 17. As the sample boider 3 has moved a distance from the support plate 13 of the transfer unit 4, there will be equilibrium between the magnetic forces interacting between the first and second magnetic unit 10, 14 and the weight of the sample holder 3, the sample acquiring device 7 and the sample. The sample holder 3 is now in its second position 19. The second position 19 can also be constituted of that the magnetic interaction of the first and the second magnet units 10,14 presses the sample holder 3 against a second abutment. The second position 19 is a position in the apparatus 1 in which the sample in the sample acquiring device 7 is located at a predetermined distance from the lens arrangement 6 of the image capturing unit 2. This predetermined distance is calibrated so that the fixed focal plane of the lens arrangement 6 correlates to the position of sample such that the image capturing unit 2 can capture a desired image, To remove the cuvette 7 from the apparatus 1, the handle 16 of the transfer unit 4 is turned 15-degrees in the opposite direction. After turning, the third magnet unit 15 will be arranged in such a close relation with the first magnet unit 10 that they may magnetically interact. Interaction by means of attracting magnetic forces will move the sample holder 3 and press it against the support plate 13 of the transfer unit 4. Thereafter the handle 16 is turned another 75 degrees and thereby the sample holder 3 is transferred back to the inje't SLdiiuii 5. When an image of a sample is to be captured, a volume of the sample, for instance a blood sample, is acquired in a cuvette 7. The volume of the sample can be relatively large, i.e. the volume of the sample allows particles therein to be located in a 3-dimensional relation to each other. For instance, the sample may be acquired into a measurement cavity having a thickness of UOum, The transfer unit 4 and the sample holder 3 are arranged In the inlet station 5. The first and the third magnet unit 10, 15 interact and keep the sample holder 3 stabile. The cuvette 7 is arranged in the inlet station 5 and the sample holder 3 receives it. The handle 16 of the transfer unit 4 is turned 90 degrees. As support plate 13 of the transfer unit 4 Is moved, the sample holder 3 is moved to the first position 18. In the first position 18 the first and the second magnet units 10. 14 interact and the sample holder 3, and thus also the cuvette 7 and the sampie retained by the cuvette 7, is moved to the second position 19, In the second position 19 the sample is located at a predetenninsd distance from the lens arrangement 6 of the image capturing unit 2, in which the fixed focal plane of the tens arrangement 6 correlates with the sample in a desired way. The measurement cavity of the cuvette 7 is ti~.us placed such that the entire thickness of the measurement cavity is within the field of image capturing unit 2. The image capturing unit 2 thereafter captures an image of the sample via the lens arrangement 6. Thereafter the image can be forwarded from the image capturing unit 2 to a computer or an image processing unit. In a second embodiment of the invention the apparatus further comprises an image processing unit (not shown), see Fig. 5. The image capturing unit 2 forwards the image captured of the sampie to the image processing unit. The image processing unit then analyzes the image of the sample, for instance it can be used to count the number of white blood cells in a blood sample, and display the result on a display 21. The sample holder 3 is held in piace in the inlet station 2 by magnetic interaction of the first and the third magnet unit 10, 15, the sample holders is thus easy to remove from the apparatus 1. A user could grasp the sample holder 3 and remove it by applying a pulling force that exceeds the magnetic force between the first and the third magnet units 10, 15, If some part of the sample leaks from the sampie acquiring device 7 ii wiii ba uui:t,..itiu in ilic sample holder 3, It is thus an advantage that the sample holder 3 is easy to clean. If the sample holder 3 is contaminated with remains from an old sample, the image of the sample could be incorrect. Although the invention above has been described In connection with preferred embodiments of the invention, it will be evident for a person skilled in the art that several modification are conceivable without departing from the invention as defined by the following claim. CLAIMS 1. Apparatus (1) for capturing an image of a sample retained by a sample acquiring device (7), comprising an image capturing unit (2) comprising a lens arrangement (6) with a fixed focal plane a sample holder (3") comprising a first magnet unit (10), and a second magnet ur.it (14), the sample holder (3) being adapted to receive the sample acquiring device (7) and being movable in relation to the lens arrangement (6) to a first position (18), in which first position (18) the first and the second magnet unit (10, 14) are arranged in such close relation that they may magnetically interact, the sample holder (3) being movable from the first position (18) to a second position (19) by means of magnetic interaction of the first magnet unit (10) and the second magnet unit (14), and the image capturing unit (2) being adapted to capturing an image of the sample by means of the lens arrangement (6) when the sample holder (3) is in the second position (19). 2. Apparatus (1) according to claim 1, further comprising an inlet station (5)„ the sample holder (3) being adapted to receive said sample acquiring device (7) in said inlet station (5). 3. Apparatus (1) according to claim 2, further comprising a third magnet unit 05), the third magnet (15} unit being adapted to position the sample holder (15) in the inlet station (5) by means of magnetic interaction of the first magnet unit (10) and the third magnet unit (15). 4. Apparatus (1) according to claim 2 or 3, further comprising a transfer unit (4), the transfer unit (4) being arranged to support the sample holder (4) and to transfer said sample holder (4) from the inlet station (5) to the first position (18). 5. Apparatus (1) according to claim 4, wherein the transfer unit (4) is movable between the Inlet station (5) and a position in which the sample holder (3) is positioned in the first position (18). 6. Apparatus (1) according to claim 4 or 5, wherein the second magnet unit (14) is arranged on the transfer unit (4). 7. Apparatus (1) according to any ons of claims 4 to 5. wherein the third magnet unit (15) is arranged on the transfer unit (4), 8. Apparatus (1) according to any on of the preceding claims, further comprising an alignment means (20) for aligning the sample holder (3) in relation to the lens arrangement (6) when it is moved from the first to the second position (18, 19). 9. Apparatus (1) according to any one of claims 4 to 1, wherein the alignment means (20) is arranged on the transfer unit (4). 10. Apparatus (1) according to anyone of the preceding claims, wherein the first and the second magnet unit (10, 14) are arranged to move the sample holder (3) from the first position (18) to the second position (19) by means of repellent magnetic forces. 11. Apparatus (1) according to anyone of claims 3 to 10, wherein the first and the third magnet unit (10, 15) are arranged to position the sample holder (3) in the inlet station (5) by means of attracting magnetic forces. 12. Apparatus (1) according to any one of the preceding claims, wherein the sample holder (3) is adapted to receive a sample acquiring device (7) in the form of a cuvette (7). 13. Apparatus (1) according to anyone of the preceding claims, further comprising an image processing unit, the image processing unit being adapted to process an image of the sample. 14. Apparatus (1) according to claim 13, wherein the 'image processing unit is adapxea to identify and count particles in the samplo- 15. Method forcaptunng an image of a sample in a sample acquiring device (7), said method comprising: positioning the sample acquiring device (7) in a sample holder (3) comprising a first magnet unit (10), transferring said sample holder (3) in relation to a iens arrangement (6) with a fixed focal plane of an image capturing unit (2) to a first position (18), in which first position (18) the first and a second magnet unit (10, 14) are arranged in such close relation that they may magnetically interact, moving the sample holder (3) from the first position (18) to a second position (19) by means of magnetic interaction of the first magnet unit (10) and the second magnet unit (14), and capturing an image of the sample by means of the lens arrangement (6) when the sample holder (3) is in the second position (19). 1S. Method according to claim 15, further comprising: processing said image in an image processing unit in order to identify and count particles in the sample.

Full Text

APPARATUS FOR CAPTURING AN IMAGE
Field of the Invention
The present invention relates to an apparatus and a method for caoturing an image of a sample retained by a sample acquiring devjc-s.
Background Art
The apparatus and the method described by Way of introduction are used to capture an image of a sample for analysing the sample.
PCT/SE2006/000311 (not public at filing of this application) and US 6,710,879 disclose methods for analysing a volume of a sample by processing an image of the sample.
To capture an image of the sample, the sample is in some cases placed under a tens arrangement with either an adjustable focal plane or a lens arrangement with a fixed focal plane.
The problems with the lens arrangements with an adjustable focal plane are that they are expensive and it is difficult to adjust the focal plane of the lens arrangement to a correct position in relation to the sample.
The problems with the lens arrangements with a fixed focal plane are that the sample, for instance retained in a cuvette, has to be located in the exact same relation to the fixed focal plane of the lens arrangement each .time an image is captured to obtain a reliable result.
An object of the present invention is to provide an apparatus that can capture an image of a sample retained in a sample acquiring device in a more effective way.
Summary of the Invention
The present invention is new and inventive by providing an apparatus according to claim 1 and a method according to claim 15. Embodiments of the invention are described in the dependent claims.
The inventive apparatus for capturing an image of a sample retained by a sample acquiring device, comprises an image capturing unit comprising a lens arrangement with a fixed focal plane, a sample holder comprising a first magnet unit, and a second magnet unit, the sample holder being adapted to receive the sample acquiring device and being movable in relation to the lens

arrangsment to a first position, in whicri rirst position me rirsr ana tne seoona magnet unit are arranged in such close relation that they may magnetically interact, the sample holder being movable from the first position to a second position by means of magnetic interaction of the first magnet unit and the second magnet unit, and the image capturing unit being adapted to capture an image of the sample by means of the lens arrangement when the sample holder is in the second position
This provides the advantage that the sample holder can be arranged in the second position with high accuracy and that a lens arrangement with a fixed focal point can be used to capture a reliable image of a sample.
This also provides the advantages that the number of moving mechanical parts for moving the sample holder from the first position to the second position is reduced.
By reducing the number of moving mechanical parts an advantage is obtained in that the influence of the tolerances of each part is reduced. This is particularly advantageous when the sample acquiring device provides a sample thickness equal or marginally smaller than a depth of field of the image capturing unit. In such cases, a slight malpositioning of the sample acquiring device would render analysis of the captured image impossible or, worse, would render incorrect results of the analysis.
A further advantage is that by moving the sample holder by means of magnetic interaction, the wear of the apparatus is reduced.
To introduce a sample acquiring device in an easy and reliable way the apparatus can further comprise an inlet station, the sample hoidei Leiuy adapted to receive said sample acquiring device in said inlet station.
To achieve the advantages of positioning the sample holder in a reliable, easy and exact position the apparatus can further comprise a third magnet unit, the third magnet unit being adapted to position the sample holder in the inlet station by means of magnetic interaction of the first magnet unit and the third magnet unit. A further advantage is that the sample holder is easy to remove from the apparatus for cleaning.
The apparatus can further comprise a transfer unit, the transfer unit being arranged to support the sample holder and to transfer said sample holder from the inlet station to the first position. This leads to the advantages that the sample holder can be transferred in an easy, reliable and correct way.

The transfer unit of the apparatus can be movable between the inlet station and a position in which the sampis holder is positioned in the first position.
To achieve the advantages of increasing the reliability of the apparatus, the second magnet unit of the apparatus can be arranged on the transfer unit.
To increase the reliability of the apparatus and to support the sample holder Vi/hen it is moved fron-. the inlet station to ihe first position the third magnet unit of the apparatus can be arranged on the transfer unit,
To reduce the tolerance with which the sample holder is positioned in the second position the apparatus can further comphse an alignment means for aligning the sample holder in relation to the lens arrangement when it is moved from the first to the second position.
The alignment means of the apparatus can be arranged on the transfer unit.
The first and the second magnet unit of the apparatus can be arranged to move the sample holder from the first position to the second position Dy means of repellent magnetic forces. This leads to the advantages that the sample holder is arranged in the second position with a very high tolerance.
To achieve the advantages of the sample holder being maintained in an correct position when it is moved the first and the third magnet unit of the apparatus can be arranged to position the sample holder in the inlet station by means of attracting magnetic forces.
The sample holder of the apparatus can be adapted to receive a sample acquiring device in the form of a cuvette.
The apparatus can further comprise an image processing unit, the image processing unit being adapted to process an image of the sample.
The image processing unit of the apparatus can be adapted to identify and count particles in the sample, in particular, the image processing unit may be adapted to identify and count biological particles, such as blood cells, in a liquid sample, such as blood.
The inventive method for capturing an image of a sample retained by a sample acquiring device, comprises: positioning the sample acquiring device in a sample holder comprising a first magnet unit, transferring said sample holder in relation to a lens arrangement with a fixed focal plane of an image capturing unit to a first position in which first position the first and a second magnet unit are arranged in such close relation that they may magnetically interact, moving the sample holder from the first position to a second position

by means of magnetic interaction of the first n-iagnet unit and the second magnet unit, and capture an image of the sample by means of the lens arrangement when the sample holder is in the second position.
Advantages of the Inventive method are that an image of a sample can be captured in a reliable and easy way.
The method can further comprise processing said image in an image processing unrt and to identify and count partic'es in tlie sarr.pie.
Brief Description of the Drawings
The invention and its many advantages will be described in more detail below with reference to the accompanying schematic drawings, which for the purpose of illustration show some non-iimiting embodiments and in which
Fig. 1 shows a plan view of an embodiment of the invention when the sample holder is arranged in the inlet station.
Fig. 2 shows a partial cross-sectional view of the embodiment in Fig. 1 along A-A.
Fig, 3 shows a plan view of an embodiment of the invention when the sample holder Is arranged in the second position.
Fig. 4 shows a partial cross-sectional view of the embodiment in Fig. 3 along B-B.
Fig. 5 shows a perspective view of a second embodiment of the invention
All figures are highly schematic, not necessarily to scale, and they show only parts, which are necessary in order to elucidate the invention, other parts being omitted or merely suggested.
Description of Preferred Embodiments
Fig. 1 and 2 show an embodiment of an apparatus according to the invention. The apparatus 1 comprises an image capturing unit 2, a sample holder 3, a transfer unit 4 and an inlet station 5. In the shown embodiment, the sample holder 3 has received a sample acquiring device 7, in the form of a cuvette 7.
The image capturing unit 2 comprises a lens arrangement 6 with a fixed focal plane. In the shown embodiment the lens arrangement 6 comprises four lenses 8, se Fig. 4.
The sample holder 3 comprises a plate 9 and a first magnet unit 10, The plate 9 comprises a central depression 11 on an upper side and a flange 12 that is arranged on the circumference of a lower side of the piate 9 and that

extends in a direction away from the upper side. The first magnet unit 10 is mounted on the lower side of the plate 9. The central depression 11 has a shape that corresponds to the shape of the sam.ple acquiring device 7-
The transfer unit 4 comprises a support plate 13. a second magnet unit 14, a third magnet unit 15 and a handle 16, The support plate 13 is curved in the direction of its length. The suoport ptate 13 comprises a depression 17 on the upper side, the shape of tiie depression ' 7 corresponds tc the shape of the sample holder 3. The second magnet unit 14 and the third magnet unit 15 are mounted on the lower side of the support plate 13. The handle 16 is mounted on the side of the support plate 13, which has the largest radius. The support plate 13 of the transfer unit 4 is movable by movement of the handle 16.
The sample holder 4 is arranged in the depression 17 of the support plate 13. As the support plate 13 ofthe transfer unit 4 is moved by turning the handle 16 the sample holder 3 moves together with support plate 13 of the transfer unit 4. The handle 16 ofthe transfer unit 4 is arranged to move the sample holder 3 between the inlet station 5 and a first position 18.
The first and third magnet unit 10, 15 are magnets being arranged with attracting magnetic poles facing each other. The first and the second magnet units 10, 14 are magnets being arranged with repeflent magnetic poles facing each other. The third magnet unit 15 is mounted on the support plate 13 in a position such that, when the samp/e holder 3 is arranged in the inlet station 5, the first and the third magnet unit 10, 15 interacts and presses the sample holder 3 against the support plate 13. To move the sample holdai' 5 io liia iiii.[ position the handle 16 of the transfer unit 4 first is turned 75 degrees, and thereby also moving the sample holder 3. After being turned 75 degrees the sample holder 3 hits an abutment (not shown). The handle 16 of transfer unit 4 is thereafter turned another 15 degrees. By doing this the support piate 13 of the transfer unit 4 is moved in relation to the sample holder 3, such that the second magnet unit 14 is aligned vi/ith the first magnet unit 10. The sample holder 3 is now in its first position 18.
To move the sample holder 3 to a second position 19 the first and the second magnet unit 10, 14 interact, see fig 3 and 4. As the first and second magnet units 10, 14 are arranged with repellent magnetic poles facing each other, the sample holder 3 will be moved upwards. The flanges 12 and an alignment means 20 of the support plate 13 interact when the sample holder 3 is moved upwards to guide the movement of and align the sample holder 3

with an optical axis of the lens arrangement 5, The alignment means 20 can be constituted of the walls 20 of the depression 17. As the sample boider 3 has moved a distance from the support plate 13 of the transfer unit 4, there will be equilibrium between the magnetic forces interacting between the first and second magnetic unit 10, 14 and the weight of the sample holder 3, the sample acquiring device 7 and the sample. The sample holder 3 is now in its second position 19.
The second position 19 can also be constituted of that the magnetic interaction of the first and the second magnet units 10,14 presses the sample holder 3 against a second abutment.
The second position 19 is a position in the apparatus 1 in which the sample in the sample acquiring device 7 is located at a predetermined distance from the lens arrangement 6 of the image capturing unit 2. This predetermined distance is calibrated so that the fixed focal plane of the lens arrangement 6 correlates to the position of sample such that the image capturing unit 2 can capture a desired image,
To remove the cuvette 7 from the apparatus 1, the handle 16 of the transfer unit 4 is turned 15-degrees in the opposite direction. After turning, the third magnet unit 15 will be arranged in such a close relation with the first magnet unit 10 that they may magnetically interact. Interaction by means of attracting magnetic forces will move the sample holder 3 and press it against the support plate 13 of the transfer unit 4. Thereafter the handle 16 is turned another 75 degrees and thereby the sample holder 3 is transferred back to
the inje't SLdiiuii 5.
When an image of a sample is to be captured, a volume of the sample, for instance a blood sample, is acquired in a cuvette 7. The volume of the sample can be relatively large, i.e. the volume of the sample allows particles therein to be located in a 3-dimensional relation to each other. For instance, the sample may be acquired into a measurement cavity having a thickness of UOum,
The transfer unit 4 and the sample holder 3 are arranged In the inlet station 5. The first and the third magnet unit 10, 15 interact and keep the sample holder 3 stabile. The cuvette 7 is arranged in the inlet station 5 and the sample holder 3 receives it.
The handle 16 of the transfer unit 4 is turned 90 degrees. As support plate 13 of the transfer unit 4 Is moved, the sample holder 3 is moved to the first position 18.

In the first position 18 the first and the second magnet units 10. 14 interact and the sample holder 3, and thus also the cuvette 7 and the sampie retained by the cuvette 7, is moved to the second position 19,
In the second position 19 the sample is located at a predetenninsd distance from the lens arrangement 6 of the image capturing unit 2, in which the fixed focal plane of the tens arrangement 6 correlates with the sample in a desired way. The measurement cavity of the cuvette 7 is ti~.us placed such that the entire thickness of the measurement cavity is within the field of image capturing unit 2.
The image capturing unit 2 thereafter captures an image of the sample via the lens arrangement 6. Thereafter the image can be forwarded from the image capturing unit 2 to a computer or an image processing unit.
In a second embodiment of the invention the apparatus further comprises an image processing unit (not shown), see Fig. 5. The image capturing unit 2 forwards the image captured of the sampie to the image processing unit. The image processing unit then analyzes the image of the sample, for instance it can be used to count the number of white blood cells in a blood sample, and display the result on a display 21.
The sample holder 3 is held in piace in the inlet station 2 by magnetic interaction of the first and the third magnet unit 10, 15, the sample holders is thus easy to remove from the apparatus 1. A user could grasp the sample holder 3 and remove it by applying a pulling force that exceeds the magnetic force between the first and the third magnet units 10, 15, If some part of the sample leaks from the sampie acquiring device 7 ii wiii ba uui:t,..itiu in ilic sample holder 3, It is thus an advantage that the sample holder 3 is easy to clean. If the sample holder 3 is contaminated with remains from an old sample, the image of the sample could be incorrect.
Although the invention above has been described In connection with preferred embodiments of the invention, it will be evident for a person skilled in the art that several modification are conceivable without departing from the invention as defined by the following claim.

CLAIMS
1. Apparatus (1) for capturing an image of a sample retained by a sample
acquiring device (7), comprising an image capturing unit (2) comprising a lens
arrangement (6) with a fixed focal plane a sample holder (3") comprising a
first magnet unit (10), and a second magnet ur.it (14),
the sample holder (3) being adapted to receive the sample acquiring device (7) and being movable in relation to the lens arrangement (6) to a first position (18), in which first position (18) the first and the second magnet unit (10, 14) are arranged in such close relation that they may magnetically interact,
the sample holder (3) being movable from the first position (18) to a second position (19) by means of magnetic interaction of the first magnet unit (10) and the second magnet unit (14), and
the image capturing unit (2) being adapted to capturing an image of the sample by means of the lens arrangement (6) when the sample holder (3) is in the second position (19).
2. Apparatus (1) according to claim 1, further comprising an inlet station
(5)„
the sample holder (3) being adapted to receive said sample acquiring device (7) in said inlet station (5).
3. Apparatus (1) according to claim 2, further comprising a third magnet
unit 05),
the third magnet (15} unit being adapted to position the sample holder (15) in the inlet station (5) by means of magnetic interaction of the first magnet unit (10) and the third magnet unit (15).
4. Apparatus (1) according to claim 2 or 3, further comprising a transfer
unit (4),
the transfer unit (4) being arranged to support the sample holder (4) and to transfer said sample holder (4) from the inlet station (5) to the first position (18).
5. Apparatus (1) according to claim 4, wherein the transfer unit (4) is movable between the Inlet station (5) and a position in which the sample holder (3) is positioned in the first position (18).
6. Apparatus (1) according to claim 4 or 5, wherein the second magnet unit (14) is arranged on the transfer unit (4).

7. Apparatus (1) according to any ons of claims 4 to 5. wherein the third magnet unit (15) is arranged on the transfer unit (4),
8. Apparatus (1) according to any on of the preceding claims, further comprising an alignment means (20) for aligning the sample holder (3) in relation to the lens arrangement (6) when it is moved from the first to the second position (18, 19).
9. Apparatus (1) according to any one of claims 4 to 1, wherein the alignment means (20) is arranged on the transfer unit (4).

10. Apparatus (1) according to anyone of the preceding claims, wherein the first and the second magnet unit (10, 14) are arranged to move the sample holder (3) from the first position (18) to the second position (19) by means of repellent magnetic forces.
11. Apparatus (1) according to anyone of claims 3 to 10, wherein the first and the third magnet unit (10, 15) are arranged to position the sample holder (3) in the inlet station (5) by means of attracting magnetic forces.
12. Apparatus (1) according to any one of the preceding claims, wherein the sample holder (3) is adapted to receive a sample acquiring device (7) in the form of a cuvette (7).
13. Apparatus (1) according to anyone of the preceding claims, further comprising an image processing unit,
the image processing unit being adapted to process an image of the sample.
14. Apparatus (1) according to claim 13, wherein the 'image processing unit is adapxea to identify and count particles in the samplo-
15. Method forcaptunng an image of a sample in a sample acquiring device (7), said method comprising:
positioning the sample acquiring device (7) in a sample holder (3) comprising a first magnet unit (10),
transferring said sample holder (3) in relation to a iens arrangement (6) with a fixed focal plane of an image capturing unit (2) to a first position (18), in which first position (18) the first and a second magnet unit (10, 14) are arranged in such close relation that they may magnetically interact,
moving the sample holder (3) from the first position (18) to a second position (19) by means of magnetic interaction of the first magnet unit (10) and the second magnet unit (14), and
capturing an image of the sample by means of the lens arrangement (6) when the sample holder (3) is in the second position (19).

1S. Method according to claim 15, further comprising: processing said image in an image processing unit in order to identify and count particles in the sample.

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Patent Number

264468

Indian Patent Application Number

346/CHENP/2009

PG Journal Number

01/2015

Publication Date

02-Jan-2015

Grant Date

30-Dec-2014

Date of Filing

19-Jan-2009

Name of Patentee

HEMOCUE AB

Applicant Address

BOX 1204, SE-262 23 ANGELHOLM

Inventors:

#	Inventor's Name	Inventor's Address
1	EMILSSON, CARL-FREDRIK	HAVSTENSVAGEN 208, SE-269 92 BASTAD

PCT International Classification Number

H01F7/16

PCT International Application Number

PCT/SE07/00654

PCT International Filing date

2007-07-04

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	0601576-2	2006-07-19	Sweden