WO2015113700A1 - Centrifuge and separation chamber for a centrifuge - Google Patents

Centrifuge and separation chamber for a centrifuge Download PDF

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Publication number
WO2015113700A1
WO2015113700A1 PCT/EP2014/078122 EP2014078122W WO2015113700A1 WO 2015113700 A1 WO2015113700 A1 WO 2015113700A1 EP 2014078122 W EP2014078122 W EP 2014078122W WO 2015113700 A1 WO2015113700 A1 WO 2015113700A1
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WO
WIPO (PCT)
Prior art keywords
separation chamber
light
centrifuge
detector
segments
Prior art date
Application number
PCT/EP2014/078122
Other languages
French (fr)
Inventor
Artur Meisberger
Michael Hock
Original Assignee
Fresenius Kabi Deutschland Gmbh
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Filing date
Publication date
Application filed by Fresenius Kabi Deutschland Gmbh filed Critical Fresenius Kabi Deutschland Gmbh
Publication of WO2015113700A1 publication Critical patent/WO2015113700A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04B—CENTRIFUGES
    • B04B5/00—Other centrifuges
    • B04B5/04—Radial chamber apparatus for separating predominantly liquid mixtures, e.g. butyrometers
    • B04B5/0407—Radial chamber apparatus for separating predominantly liquid mixtures, e.g. butyrometers for liquids contained in receptacles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04B—CENTRIFUGES
    • B04B13/00—Control arrangements specially designed for centrifuges; Programme control of centrifuges
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/04—Investigating sedimentation of particle suspensions
    • G01N15/042—Investigating sedimentation of particle suspensions by centrifuging and investigating centrifugates
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/04—Investigating sedimentation of particle suspensions
    • G01N15/05—Investigating sedimentation of particle suspensions in blood
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04B—CENTRIFUGES
    • B04B13/00—Control arrangements specially designed for centrifuges; Programme control of centrifuges
    • B04B2013/006—Interface detection or monitoring of separated components

Definitions

  • the invention relates to a centrifuge according to the preamble of claim 1 and a separation chamber for a centrifuge according to the preamble of claim 8.
  • centrifuges for separating blood into its constituents are known from the prior art. These centrifuges comprise an essentially rotationally symmetrical separation chamber made e.g. from a transparent material. The position of the separation (phase) boundaries between the separated blood constituents in the separation chamber is monitored using an optical phase boundary detector device. To detect the phase boundaries, a specific region of the separation chamber, i.e. the phase boundary window, is irradiated by means of a light source, whereby the light beams passing through the phase boundary window are detected by a light detector. Such devices are described, for example, in documents DE 33 01 1 13 A1 or DE 41 32 965 A1 .
  • irradiation of the separation chamber and evaluation of the values ascertained by the light detector can take place only when the phase boundary window of the rotating separation chamber lies between light source and light detector. It is therefore necessary to determine the position of the phase boundary window relative to the light detector.
  • a separation chamber for a centrifuge is described in EP 0 729 790 A2, wherein the separation chamber comprises a marker segment extending inclined with respect to other segments of the separation chamber.
  • the marker segment indicates a reference position of the separation chamber, wherein a scanning device scans the separation chamber to detect the marker element and thus the position of the separation chamber.
  • the position of the phase boundary window can thus be determined using the position of the marker element, i.e. the reference position of the separation chamber.
  • the object of the invention thus is to provide a centrifuge and a separation chamber for a centrifuge that can be produced cost-efficiently and as compact as possible.
  • a centrifuge in particular a medical centrifuge, is provided, the centrifuge comprising
  • the separation chamber comprising a plurality of segments, wherein at least one of the segments is a marker segment permitting the detection of the angular position of the separation chamber when inserted into the drive unit of the centrifuge, wherein the marker segment is formed in such a way that light striking the marker segment will be reflected by and/or transmitted through the separation chamber differently than light striking one of the other segments,
  • a scanning device for detecting the angular position of the separation chamber, when rotated by the drive unit, by sensing the marker segment of the separation chamber, - the scanning device comprising a light source for irradiating light onto the segments and a detector for detecting light reflected by the segments, wherein
  • the light source and the detector are arranged on a common carrier.
  • the common carrier is a (e.g. printed) circuit board providing electrical connections to both the light source and the detector.
  • the electrical connections are e.g. used for supplying power to the light source and the detector and for example for connecting at least one evaluating unit to these components.
  • the evaluating unit which may be an electronic component also arranged on the common circuit board, may be used to evaluate a signal of the detector for determining the angular position of the separation chamber and/or the position of a phase boundary between blood components separated by means of the centrifuge (see below).
  • the light source and the detector may be arranged in a common housing to form a common unit.
  • the detector is arranged in such a way that it detects light propagating in a direction essentially parallel to the direction of light generated by the light source, i.e. the detector and the light source are at least essentially orientated in the same direction.
  • the light source generates light that propagates at least essentially along the rotational axis of the separation chamber.
  • the position of the marker segment i.e. the reference position of the separation chamber, can be determined from a change of the distribution of the light received by the detector since the light distribution created by the marker segment is characteristic for the marker segment and thus for the reference position of the separation chamber.
  • the marker segment may be configured in such a way that it reflects less light into the detector than the other segments.
  • the marker segment (different from the other segments) may also be inclined with respect to the rotational axis of the separation chamber.
  • the marker segment comprises a light absorbing or light diffusing structure such that at least essentially no light is reflected by the marker segment.
  • the light source of the scanning device may be a monochromatic light source such as a laser or an LED, wherein the light detector may be a photodiode or a phototransistor.
  • the detector may also be a camera, a CCD chip or a single photodiode.
  • the light source of the scanning device may comprise at least one LED, wherein the detector of the scanning device may comprises at least one CCD chip, wherein the LED and the CCD chip are arranged on a common circuit board.
  • the centrifuge according to the invention may also comprise a phase boundary detection device for determining the position of a phase boundary between blood components separated by means of the centrifuge, wherein the detector of the scanning device also realizes a detector of the phase boundary detection device, the phase boundary detection device further comprising an evaluation unit for evaluating a signal of the detector for determining the position of a phase boundary.
  • the phase boundary detection device may comprise a light source arranged in addition to the light source of the scanning device.
  • the light source of the phase boundary detection device and the light source of the scanning device are arranged on opposite sides of the separation chamber.
  • the light source of the scanning device is also used as the light source of the phase boundary detection device.
  • the centrifuge according to the invention in particular is a blood centrifuge, e.g. an auto transfusion device (e.g. with continuous flow) for auto transfusion during and after surgery.
  • a separation chamber for a centrifuge in particular a medical centrifuge, is provided, the separation chamber being insertable into a drive unit of the centrifuge and comprising:
  • At least one of the segments is a marker segment permitting the detection of the angular position of the separation chamber when inserted into the drive unit of the centrifuge;
  • the light influencing structure integrally formed with the marker segment such that light striking the marker segment will be reflected by and/or transmitted through the separation chamber differently than light striking one of the other segments, wherein the light influencing structure is formed in such a way that light radiated onto the light influencing structure along the rotational axis of the separation chamber is absorbed or is transmitted or reflected along the rotational axis of the separation chamber.
  • the separation chamber is an injection moulded part, wherein the light influencing structure is formed together with the separation chamber during the moulding process.
  • the light influencing structure is formed only after the fabrication of the separation chamber.
  • the light influencing structure is formed by sand blasting or grinding an outer surface of the separation chamber.
  • the integration of the light influencing structure with the marker segment permits the detection of the position of the separation chamber and the control of the separation process using a single light source only. A separate light source for the detection of the position of the separation chamber may be omitted.
  • a device using the separation chamber according to the invention may be constructed more compact and cost-efficient.
  • the light influencing structure may be integrally formed with a side wall of the marker segment, the side wall delimiting an inner tillable volume of the marker segment.
  • the light influencing structure is formed as a protrusion of the side wall, wherein the light influencing structure protrudes away from the inner volume of the marker segment (e.g. the light influencing structure extends at least essentially parallel to a rotational axis of the separation chamber).
  • the light influencing structure may be configured for focussing light radiation.
  • the light influencing structure comprises a curved surface section, the curved surface section forming e.g. a lens-like structure for focussing incoming light of a light source towards a detector (see description below).
  • the marker segment of the separation chamber may comprise a plurality of light influencing structures, wherein, for example, each one of them comprises a curved surface section such that a plurality of lens-like light influencing structures is provided.
  • the light influencing structure is configured for reflecting light radiation.
  • the light influencing structure comprises a planar surface section extending inclined relative to the common plane in which the segments of the separation chamber extend.
  • the planar surface encloses an angle of at least approximately 45° with the rotational axis of the separation chamber.
  • the inclined planar surface will deflect light radiated parallel to the rotational axis of the separation by an angle of about 90°.
  • the light influencing structure comprises a plurality of planar surface sections which may be inclined under different angles relative to the rotational axis of the separation chamber.
  • the light influencing structure is formed prism-like such that it comprises a first planar surface enclosing an angle of +45° with the rotational axis of the separation chamber and a second planar surface enclosing an angle of about -45° with the rotational axis.
  • prism-like light influencing structures may be arranged. It is also conceivable that a combination of different light influencing structures is provided (including e.g. both focussing and reflective structures).
  • the marker segment and the light influencing structure are formed from a transparent plastic material.
  • the separation chamber is formed as an exchangeable, i.e. disposable, part.
  • the separation chamber is a (low cost) injection moulded plastic part as already set forth above.
  • the separation chamber may be formed as an essentially rotationally symmetrical part, wherein its segments may be annularly disposed and radially oriented with respect to the rotational axis of the separation chamber (i.e. the axis about which the separation chamber rotates when inserted into the drive unit of the centrifuge and rotated by the drive unit).
  • the common plane, along which the plurality of segments of the separation chamber extends, runs at least essentially perpendicular to the rotational axis of the separation chamber.
  • all of the segments of the separation chamber extend parallel to a common plane.
  • only some of the segments (including the marker segment) run parallel to a common plane, while other segments are orientated differently.
  • a single marker segment is provided, only.
  • FIG. 1 a centrifuge in schematic representation, the centrifuge comprising a separation chamber according to an embodiment of the invention
  • FIG. 2 the separation chamber of Fig. 1 in top view
  • FIG. 3A a section through the marker segment of the separation chamber along the line Ill-Ill in FIG. 2 in enlarged representation
  • FIG. 3B the radial distribution of light transmitted through the marker segment of the separation chamber shown in Fig. 3A;
  • FIG. 4A a section through a marker segment of a separation chamber according to another embodiment of the invention; the radial distribution of light transmitted through the marker segment of the separation chamber shown in Fig. 4A; the separation chamber of the centrifuge shown in Fig. 1 including a scanning device for determining the position of the marker segment; and a medical centrifuge according to an embodiment of the invention.
  • Fig. 1 shows a medical centrifuge 100 for separating whole blood into its constituents, wherein the centrifuge 100 comprises a drive unit 1 and a separation chamber 2 according to the invention.
  • the separation chamber 2 is inserted into the drive unit 1 such that the separation chamber 2 can be rotated by energizing the drive unit 1 .
  • the separation chamber 2 is a disposable part made from a transparent plastic material.
  • the separation chamber 2 has a central rotation axis 3 which bears, via radial crosspieces 4, an essentially annular separation channel 5 for receiving the whole blood which is separated by rotation of the separation chamber 2.
  • outer teeth 6 of the rotation axis 3 engage with teeth of driving means, not shown in the Figures, of the drive unit 1 , so that the separation chamber 2 can be set rotating.
  • an radially outer edge region of the separation chamber 2 adjacent to an outer wall of the separation channel 5 comprises a plurality of segments 8 formed by a plurality of ribs 7 arranged circumferentially distributed, wherein the segments 8 all lie in a horizontal plane, i.e. in a plane running transversely relative to the axis of rotation 3 of the separation chamber 2.
  • the centrifuge 100 may also have a phase boundary detection device, which determines the position of a phase boundary between separated blood components in the separation channel 5 of the chamber 2 and may control the delivery rate of a pump connected to the separating chamber 2 depending on the location of the phase boundaries. In particular, by means of the phase boundary detection device, the position of an interface between a blood plasma phase (e.g.
  • phase boundary detection device is described in the document DE 33 01 1 13 A1 already mentioned above, which is incorporated by reference herewith.
  • Monitoring of the phase boundary takes place within a phase boundary window 10 (FIG. 1 ) of the separation chamber 2, wherein the monitoring requires that the angular position of the separation chamber 2 is known.
  • the chamber segments 8 form a scanning region (see Fig. 5) which extends annularly around the rotation axis 3 of the separation chamber 2. More particularly, one of the segments 8 forms a marker segment 8' permitting the detection of the angular position of the separation chamber.
  • the separation chamber 2 comprises a plurality of light influencing structures integrally formed with the marker segment 8' such that light striking the marker segment 8' will be reflected by and/or transmitted through the separation chamber 2 differently than light striking one of the other segments 8.
  • FIG. 3A A first example of light influencing structures 81 a formed with the marker segment 8' is shown in Fig. 3A.
  • the light influencing structures 81 a each protrude away from an inner volume 80' of the marker segment 8', the inner volume 80' being delimited by a side wall 801 '.
  • the light influencing structures 81 a each comprise a curved outer surface 81 1 , wherein the curved sections 81 1 form a semi- spherical surface such that the light influencing structures 81 a act as lenses focussing incoming light beams 16 such that partially focussed radiation 16" is generated.
  • the corresponding radial light distribution of the transmitted light radiation is schematically shown in Figure 3B.
  • the intensity I of the transmitted radiation has maxima at radial positions ("r" designating the radial position) corresponding to the radial positions of the lens-like light influencing structures 81 a, i.e. the intensity of light transmitted through the light influencing structures 81 a is higher than the intensity of light transmitted through the flat regions of the marker segment side wall 801 ' between the light influencing structures 81 a.
  • a light detector (not shown in Fig. 3A) may be positioned at the radial position of at least one of the light influencing structures 801 ' such that an increase of the detector signal will be observed when the marker segment 8 passes through the light beam 16 such that the position of the marker segment can be determined (see Fig. 5 discussed below).
  • FIG. 4A Another embodiment of the separation chamber 2 is illustrated in Fig. 4A, wherein the marker chamber 8' comprises prism-like light influencing structures 81 b.
  • the prism-like light influencing structures 81 b each comprise two planar surfaces 812 orientated inclined relative to the rotational axis 3 of the separation chamber 2. More particularly, the planar surfaces 812 each extend with an angle of about 45° relative to the axis 3.
  • the incoming light beam 16 thus is deflected by the planar surfaces 812 in a direction perpendicular to the axis 3. Therefore, the transmission of light drops (or may even be eliminated) in the region of the light influencing structures 81 b.
  • the corresponding distribution of light transmitted through the marker segment 8' is schematically shown in Fig. 4B.
  • FIG. 5 depicts the separation chamber 2 of centrifuge 100 of Fig. 1 , wherein in addition a scanning device 1 1 for detecting the angular position of the separation chamber 2 is provided.
  • the scanning device comprises a light source 12 generating radiation striking the region of segments 8 of the separation chamber 2.
  • the light transmitted through that region of separation chamber 2 is detected by a detector device 13 positioned in the beam path of the transmitted light 16", the detector device 13 comprising a light detector 14 (e.g. a single photo diode, a diode array or a camera) and an evaluation unit 15.
  • the detector device 13 may comprise a lens arrangement for focussing the transmitted light.
  • the intensity of the light arriving at the detector 14 may rise (light influencing structures forming lens-like structures as shown in Fig. 3A) or drop (light influencing structures forming prism-like structures as shown in Fig. 4A) when the marker segment 8' passes light beam 16. Therefore, by evaluating the signal of detector 14 using the evaluation unit 15 it is possible to sense when the marker segment 8' passes through the light beam 16, i.e. to sense the position of the marker segment 8'. For example, the evaluation unit 15 senses that the marker segment 8' crosses light beam 16 if the light intensity at the detector 14 exceeds a predetermined threshold (e.g. in case the light influencing structures are formed according to Fig. 3A) or drops below a predetermined threshold (e.g. in case the light influencing structures are formed according to Fig. 4A).
  • a predetermined threshold e.g. in case the light influencing structures are formed according to Fig. 3A
  • a predetermined threshold e.g. in case the light influencing structures are formed according to Fig.
  • the light source 12 and the detector 14 may also form part of a phase boundary detection device for detecting a phase boundary between blood components as set forth above. For this, the light source 12 not only illuminates the segments 8 but also the region of the separation channel 5 (including the phase boundary window 10).
  • the invention is, of course, not restricted to the transmission sensing arrangement shown in Fig. 5. Rather, the detector device 13 may also be arranged relative to the light source 12 and the segments 8 of the separation chamber 2 in such a way that it detects light radiation reflected by the segments 8 (see Fig. 6). Further, configurations of transmitting or reflecting light influencing structures other than those illustrated in Fig. 3A and 4A could be used.
  • the detector 14 and a light source 12' (e.g. at least one LED) of the scanning device 1 1 form a common unit, wherein the detector 14 might be a camera or a CCD chip (which may also be used as part of a phase boundary detection device for monitoring the blood separation process during operation of the separation chamber 2). More particularly, according to the embodiment of Fig. 6 the light source 12' and the detector 14 are arranged on a common carrier in the form of a common circuit board (not shown).
  • the separation chamber 2 may differ from the ones shown in the previous Figures.
  • the detector 14 registers light that is reflected by and not transmitted through the marker segment 8'. It is further noted that even if the separation chamber 2 is formed from a transparent plastic material, a portion of the light generated by the light source 12 will be reflected, this reflected portion being sufficient for detecting the marker segment 8'. It is also possible that the light influencing structure of the marker segment 8' is formed in such a way essentially no light will be reflected back into the detector 14 or that the reflected light comprises a characteristic pattern.
  • the marker segment (different from the other segments) may be inclined with respect to a horizontal plane such that light will be reflected at the marker segment in such a way that the reflected light does not propagate towards the detector 14, while light reflected at the other segments will hit the detector 14 as shown in Fig. 6.
  • the centrifuge 100 shown in Fig. 6 comprises another light source 12" that forms part of a phase boundary detection device for detecting a phase boundary between blood components and as such is arranged in such a way and provides sufficient light intensity that the separation channel 5 of the separation chamber 2 is illuminated.
  • the light produced by the light source 12" is detected also by the detector 14, wherein the evaluation unit 15 may be configured for also evaluating a detector signal for determining a phase boundary.

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Abstract

The invention relates to a centrifuge, in particular a medical centrifuge, comprising a drive unit (1), a separation chamber (2) inserted into the drive unit, the separation chamber (2) comprising a plurality of segments (8), wherein at least one of the segments (8) is a marker segment (8') permitting the detection of the angular position of the separation chamber (2) when inserted into the drive unit (1) of the centrifuge (100), wherein the marker segment (8') is formed in such a way that light striking the marker segment (8') will be reflected by and/or transmitted through the separation chamber (2) differently than light striking one of the other segments, a scanning device (11) for detecting the angular position of the separation chamber (2), when rotated by the drive unit (1), by sensing the marker segment (8') of the separation chamber (2), the scanning device comprising a light source (12') for irradiating light onto the segments (8) and a detector (14) for detecting light reflected by the segments (8). According to the invention, the light source (12') and the detector (14) are arranged on a common carrier. The invention also relates to a separation chamber for a centrifuge.

Description

Centrifuge and Separation Chamber for a Centrifuge
Description
The invention relates to a centrifuge according to the preamble of claim 1 and a separation chamber for a centrifuge according to the preamble of claim 8.
Medical centrifuges for separating blood into its constituents are known from the prior art. These centrifuges comprise an essentially rotationally symmetrical separation chamber made e.g. from a transparent material. The position of the separation (phase) boundaries between the separated blood constituents in the separation chamber is monitored using an optical phase boundary detector device. To detect the phase boundaries, a specific region of the separation chamber, i.e. the phase boundary window, is irradiated by means of a light source, whereby the light beams passing through the phase boundary window are detected by a light detector. Such devices are described, for example, in documents DE 33 01 1 13 A1 or DE 41 32 965 A1 . In order to avoid the detection of error signals, irradiation of the separation chamber and evaluation of the values ascertained by the light detector can take place only when the phase boundary window of the rotating separation chamber lies between light source and light detector. It is therefore necessary to determine the position of the phase boundary window relative to the light detector. Further, a separation chamber for a centrifuge is described in EP 0 729 790 A2, wherein the separation chamber comprises a marker segment extending inclined with respect to other segments of the separation chamber. The marker segment indicates a reference position of the separation chamber, wherein a scanning device scans the separation chamber to detect the marker element and thus the position of the separation chamber. The position of the phase boundary window can thus be determined using the position of the marker element, i.e. the reference position of the separation chamber. Since the position of the phase boundary window is determined by a marker segment of the chamber itself, the chamber can be inserted in any position into the drive unit of the centrifuge and does not have to be inserted into a pre-defined position. The object of the invention thus is to provide a centrifuge and a separation chamber for a centrifuge that can be produced cost-efficiently and as compact as possible.
According to the invention, a centrifuge, in particular a medical centrifuge, is provided, the centrifuge comprising
- a drive unit,
- a separation chamber inserted into the drive unit,
- the separation chamber comprising a plurality of segments, wherein at least one of the segments is a marker segment permitting the detection of the angular position of the separation chamber when inserted into the drive unit of the centrifuge, wherein the marker segment is formed in such a way that light striking the marker segment will be reflected by and/or transmitted through the separation chamber differently than light striking one of the other segments,
- a scanning device for detecting the angular position of the separation chamber, when rotated by the drive unit, by sensing the marker segment of the separation chamber, - the scanning device comprising a light source for irradiating light onto the segments and a detector for detecting light reflected by the segments, wherein
- the light source and the detector are arranged on a common carrier.
Arranging both the light source and the detector on a common carrier permits a more compact and cost-efficient design of the centrifuge. For example, the common carrier is a (e.g. printed) circuit board providing electrical connections to both the light source and the detector. The electrical connections are e.g. used for supplying power to the light source and the detector and for example for connecting at least one evaluating unit to these components. The evaluating unit, which may be an electronic component also arranged on the common circuit board, may be used to evaluate a signal of the detector for determining the angular position of the separation chamber and/or the position of a phase boundary between blood components separated by means of the centrifuge (see below). Further, the light source and the detector may be arranged in a common housing to form a common unit. According to an embodiment of the invention, the detector is arranged in such a way that it detects light propagating in a direction essentially parallel to the direction of light generated by the light source, i.e. the detector and the light source are at least essentially orientated in the same direction. In particular, the light source generates light that propagates at least essentially along the rotational axis of the separation chamber.
The position of the marker segment, i.e. the reference position of the separation chamber, can be determined from a change of the distribution of the light received by the detector since the light distribution created by the marker segment is characteristic for the marker segment and thus for the reference position of the separation chamber. For example, the marker segment may be configured in such a way that it reflects less light into the detector than the other segments.
The marker segment (different from the other segments) may also be inclined with respect to the rotational axis of the separation chamber. Thus, light radiated onto the segments along the rotational axis of the separation chamber will be reflected by the marker segment in such a way that the reflected light does not hit the detector, while the other segments reflect the light (e.g. along the rotational axis of the separation chamber) in such a way that the light is detected by the detector. Therefore, the position of the marking segment can be sensed by detecting a difference of the light intensity at the detector. It is also possible that instead of an inclined marker segment, the marker segment comprises a light absorbing or light diffusing structure such that at least essentially no light is reflected by the marker segment.
Further more, the light source of the scanning device may be a monochromatic light source such as a laser or an LED, wherein the light detector may be a photodiode or a phototransistor. The detector may also be a camera, a CCD chip or a single photodiode. In particular, the light source of the scanning device may comprise at least one LED, wherein the detector of the scanning device may comprises at least one CCD chip, wherein the LED and the CCD chip are arranged on a common circuit board. The centrifuge according to the invention may also comprise a phase boundary detection device for determining the position of a phase boundary between blood components separated by means of the centrifuge, wherein the detector of the scanning device also realizes a detector of the phase boundary detection device, the phase boundary detection device further comprising an evaluation unit for evaluating a signal of the detector for determining the position of a phase boundary.
The phase boundary detection device may comprise a light source arranged in addition to the light source of the scanning device. For example, the light source of the phase boundary detection device and the light source of the scanning device are arranged on opposite sides of the separation chamber. However, it is also conceivable that the light source of the scanning device is also used as the light source of the phase boundary detection device. The centrifuge according to the invention in particular is a blood centrifuge, e.g. an auto transfusion device (e.g. with continuous flow) for auto transfusion during and after surgery.
According to another aspect of the invention, a separation chamber for a centrifuge, in particular a medical centrifuge, is provided, the separation chamber being insertable into a drive unit of the centrifuge and comprising:
- a plurality of segments extending at least essentially parallel to a common plane,
- wherein at least one of the segments is a marker segment permitting the detection of the angular position of the separation chamber when inserted into the drive unit of the centrifuge; and
- at least one light influencing structure integrally formed with the marker segment such that light striking the marker segment will be reflected by and/or transmitted through the separation chamber differently than light striking one of the other segments, wherein the light influencing structure is formed in such a way that light radiated onto the light influencing structure along the rotational axis of the separation chamber is absorbed or is transmitted or reflected along the rotational axis of the separation chamber.
For example, the separation chamber is an injection moulded part, wherein the light influencing structure is formed together with the separation chamber during the moulding process. However, it is also possible that the light influencing structure is formed only after the fabrication of the separation chamber. For example, the light influencing structure is formed by sand blasting or grinding an outer surface of the separation chamber. The integration of the light influencing structure with the marker segment, for example, permits the detection of the position of the separation chamber and the control of the separation process using a single light source only. A separate light source for the detection of the position of the separation chamber may be omitted. Thus, a device using the separation chamber according to the invention may be constructed more compact and cost-efficient.
The light influencing structure may be integrally formed with a side wall of the marker segment, the side wall delimiting an inner tillable volume of the marker segment. For example, the light influencing structure is formed as a protrusion of the side wall, wherein the light influencing structure protrudes away from the inner volume of the marker segment (e.g. the light influencing structure extends at least essentially parallel to a rotational axis of the separation chamber).
Further more, the light influencing structure may be configured for focussing light radiation. For example, the light influencing structure comprises a curved surface section, the curved surface section forming e.g. a lens-like structure for focussing incoming light of a light source towards a detector (see description below). Of course, the marker segment of the separation chamber may comprise a plurality of light influencing structures, wherein, for example, each one of them comprises a curved surface section such that a plurality of lens-like light influencing structures is provided.
According to another embodiment of the invention, the light influencing structure is configured for reflecting light radiation. For example, the light influencing structure comprises a planar surface section extending inclined relative to the common plane in which the segments of the separation chamber extend. For example, the planar surface encloses an angle of at least approximately 45° with the rotational axis of the separation chamber. Thus, the inclined planar surface will deflect light radiated parallel to the rotational axis of the separation by an angle of about 90°. It is also possible that the light influencing structure comprises a plurality of planar surface sections which may be inclined under different angles relative to the rotational axis of the separation chamber. For example, the light influencing structure is formed prism-like such that it comprises a first planar surface enclosing an angle of +45° with the rotational axis of the separation chamber and a second planar surface enclosing an angle of about -45° with the rotational axis. Of course, several prism-like light influencing structures may be arranged. It is also conceivable that a combination of different light influencing structures is provided (including e.g. both focussing and reflective structures).
For example, the marker segment and the light influencing structure are formed from a transparent plastic material. According to another embodiment of the invention, the separation chamber is formed as an exchangeable, i.e. disposable, part. For example, the separation chamber is a (low cost) injection moulded plastic part as already set forth above.
Moreover, the separation chamber may be formed as an essentially rotationally symmetrical part, wherein its segments may be annularly disposed and radially oriented with respect to the rotational axis of the separation chamber (i.e. the axis about which the separation chamber rotates when inserted into the drive unit of the centrifuge and rotated by the drive unit). The common plane, along which the plurality of segments of the separation chamber extends, runs at least essentially perpendicular to the rotational axis of the separation chamber.
It is noted that, in particular, all of the segments of the separation chamber extend parallel to a common plane. However, it is also conceivable that only some of the segments (including the marker segment) run parallel to a common plane, while other segments are orientated differently. Further, according to an embodiment, a single marker segment is provided, only.
Embodiments of the invention are described in more detail hereinafter with reference to the drawings. These show:
FIG. 1 a centrifuge in schematic representation, the centrifuge comprising a separation chamber according to an embodiment of the invention;
FIG. 2 the separation chamber of Fig. 1 in top view; FIG. 3A a section through the marker segment of the separation chamber along the line Ill-Ill in FIG. 2 in enlarged representation;
FIG. 3B the radial distribution of light transmitted through the marker segment of the separation chamber shown in Fig. 3A;
FIG. 4A a section through a marker segment of a separation chamber according to another embodiment of the invention; the radial distribution of light transmitted through the marker segment of the separation chamber shown in Fig. 4A; the separation chamber of the centrifuge shown in Fig. 1 including a scanning device for determining the position of the marker segment; and a medical centrifuge according to an embodiment of the invention.
Fig. 1 shows a medical centrifuge 100 for separating whole blood into its constituents, wherein the centrifuge 100 comprises a drive unit 1 and a separation chamber 2 according to the invention. The separation chamber 2 is inserted into the drive unit 1 such that the separation chamber 2 can be rotated by energizing the drive unit 1 . Preferably, the separation chamber 2 is a disposable part made from a transparent plastic material. As depicted (see also Fig. 2), the separation chamber 2 has a central rotation axis 3 which bears, via radial crosspieces 4, an essentially annular separation channel 5 for receiving the whole blood which is separated by rotation of the separation chamber 2. When the separation chamber 2 is inserted into the drive unit 1 of the centrifuge 100, outer teeth 6 of the rotation axis 3 engage with teeth of driving means, not shown in the Figures, of the drive unit 1 , so that the separation chamber 2 can be set rotating.
Further, an radially outer edge region of the separation chamber 2 adjacent to an outer wall of the separation channel 5 comprises a plurality of segments 8 formed by a plurality of ribs 7 arranged circumferentially distributed, wherein the segments 8 all lie in a horizontal plane, i.e. in a plane running transversely relative to the axis of rotation 3 of the separation chamber 2. The centrifuge 100 may also have a phase boundary detection device, which determines the position of a phase boundary between separated blood components in the separation channel 5 of the chamber 2 and may control the delivery rate of a pump connected to the separating chamber 2 depending on the location of the phase boundaries. In particular, by means of the phase boundary detection device, the position of an interface between a blood plasma phase (e.g. further comprising chlorides and and/or an anticoagulance) and a red blood cell phase can be determined. An example of a phase boundary detection device is described in the document DE 33 01 1 13 A1 already mentioned above, which is incorporated by reference herewith. Monitoring of the phase boundary takes place within a phase boundary window 10 (FIG. 1 ) of the separation chamber 2, wherein the monitoring requires that the angular position of the separation chamber 2 is known. The chamber segments 8 form a scanning region (see Fig. 5) which extends annularly around the rotation axis 3 of the separation chamber 2. More particularly, one of the segments 8 forms a marker segment 8' permitting the detection of the angular position of the separation chamber. For this, the separation chamber 2 comprises a plurality of light influencing structures integrally formed with the marker segment 8' such that light striking the marker segment 8' will be reflected by and/or transmitted through the separation chamber 2 differently than light striking one of the other segments 8.
A first example of light influencing structures 81 a formed with the marker segment 8' is shown in Fig. 3A. According to this example, the light influencing structures 81 a each protrude away from an inner volume 80' of the marker segment 8', the inner volume 80' being delimited by a side wall 801 '. Further, the light influencing structures 81 a each comprise a curved outer surface 81 1 , wherein the curved sections 81 1 form a semi- spherical surface such that the light influencing structures 81 a act as lenses focussing incoming light beams 16 such that partially focussed radiation 16" is generated.
The corresponding radial light distribution of the transmitted light radiation is schematically shown in Figure 3B. The intensity I of the transmitted radiation has maxima at radial positions ("r" designating the radial position) corresponding to the radial positions of the lens-like light influencing structures 81 a, i.e. the intensity of light transmitted through the light influencing structures 81 a is higher than the intensity of light transmitted through the flat regions of the marker segment side wall 801 ' between the light influencing structures 81 a.
A light detector (not shown in Fig. 3A) may be positioned at the radial position of at least one of the light influencing structures 801 ' such that an increase of the detector signal will be observed when the marker segment 8 passes through the light beam 16 such that the position of the marker segment can be determined (see Fig. 5 discussed below).
Another embodiment of the separation chamber 2 is illustrated in Fig. 4A, wherein the marker chamber 8' comprises prism-like light influencing structures 81 b. The prism-like light influencing structures 81 b each comprise two planar surfaces 812 orientated inclined relative to the rotational axis 3 of the separation chamber 2. More particularly, the planar surfaces 812 each extend with an angle of about 45° relative to the axis 3. The incoming light beam 16 thus is deflected by the planar surfaces 812 in a direction perpendicular to the axis 3. Therefore, the transmission of light drops (or may even be eliminated) in the region of the light influencing structures 81 b. The corresponding distribution of light transmitted through the marker segment 8' is schematically shown in Fig. 4B. Fig. 5 depicts the separation chamber 2 of centrifuge 100 of Fig. 1 , wherein in addition a scanning device 1 1 for detecting the angular position of the separation chamber 2 is provided. The scanning device comprises a light source 12 generating radiation striking the region of segments 8 of the separation chamber 2. The light transmitted through that region of separation chamber 2 is detected by a detector device 13 positioned in the beam path of the transmitted light 16", the detector device 13 comprising a light detector 14 (e.g. a single photo diode, a diode array or a camera) and an evaluation unit 15. Further, the detector device 13 may comprise a lens arrangement for focussing the transmitted light. Depending on the configuration of the light influencing structures the intensity of the light arriving at the detector 14 may rise (light influencing structures forming lens-like structures as shown in Fig. 3A) or drop (light influencing structures forming prism-like structures as shown in Fig. 4A) when the marker segment 8' passes light beam 16. Therefore, by evaluating the signal of detector 14 using the evaluation unit 15 it is possible to sense when the marker segment 8' passes through the light beam 16, i.e. to sense the position of the marker segment 8'. For example, the evaluation unit 15 senses that the marker segment 8' crosses light beam 16 if the light intensity at the detector 14 exceeds a predetermined threshold (e.g. in case the light influencing structures are formed according to Fig. 3A) or drops below a predetermined threshold (e.g. in case the light influencing structures are formed according to Fig. 4A).
The light source 12 and the detector 14 may also form part of a phase boundary detection device for detecting a phase boundary between blood components as set forth above. For this, the light source 12 not only illuminates the segments 8 but also the region of the separation channel 5 (including the phase boundary window 10).
It is noted that the invention is, of course, not restricted to the transmission sensing arrangement shown in Fig. 5. Rather, the detector device 13 may also be arranged relative to the light source 12 and the segments 8 of the separation chamber 2 in such a way that it detects light radiation reflected by the segments 8 (see Fig. 6). Further, configurations of transmitting or reflecting light influencing structures other than those illustrated in Fig. 3A and 4A could be used.
As illustrated in Fig. 6, it is further conceivable that the detector 14 and a light source 12' (e.g. at least one LED) of the scanning device 1 1 form a common unit, wherein the detector 14 might be a camera or a CCD chip (which may also be used as part of a phase boundary detection device for monitoring the blood separation process during operation of the separation chamber 2). More particularly, according to the embodiment of Fig. 6 the light source 12' and the detector 14 are arranged on a common carrier in the form of a common circuit board (not shown).
It is noted that in the embodiment of Fig. 6, the separation chamber 2 may differ from the ones shown in the previous Figures. In particular, the detector 14 registers light that is reflected by and not transmitted through the marker segment 8'. It is further noted that even if the separation chamber 2 is formed from a transparent plastic material, a portion of the light generated by the light source 12 will be reflected, this reflected portion being sufficient for detecting the marker segment 8'. It is also possible that the light influencing structure of the marker segment 8' is formed in such a way essentially no light will be reflected back into the detector 14 or that the reflected light comprises a characteristic pattern. For example, the marker segment (different from the other segments) may be inclined with respect to a horizontal plane such that light will be reflected at the marker segment in such a way that the reflected light does not propagate towards the detector 14, while light reflected at the other segments will hit the detector 14 as shown in Fig. 6.
In addition to the light source 12', the centrifuge 100 shown in Fig. 6 comprises another light source 12" that forms part of a phase boundary detection device for detecting a phase boundary between blood components and as such is arranged in such a way and provides sufficient light intensity that the separation channel 5 of the separation chamber 2 is illuminated. The light produced by the light source 12" is detected also by the detector 14, wherein the evaluation unit 15 may be configured for also evaluating a detector signal for determining a phase boundary.
Reference signs
1 drive unit
2 separation chamber
3 rotational axis
4 crosspiece
5 separation channel
6 teeth
7 rib
8 segment
8' marker segment
10 phase boundary window
1 1 scanning device
12, 12', 12" light source
13 detector device
14 detector
15 evaluation unit
16 incoming light beam
16" transmitted light beam
80' interior volume
81 a, 81 b light influencing structure
801 ' side wall
81 1 curved section
812 planar surface

Claims

Claims
1 . A centrifuge, in particular a medical centrifuge, comprising
- a drive unit (1 ),
- a separation chamber (2) inserted into the drive unit,
- the separation chamber (2) comprising a plurality of segments (8), wherein at least one of the segments (8) is a marker segment (8') permitting the detection of the angular position of the separation chamber (2) when inserted into the drive unit (1 ) of the centrifuge (100), wherein the marker segment (8') is formed in such a way that light striking the marker segment (8') will be reflected by and/or transmitted through the separation chamber (2) differently than light striking one of the other segments,
- a scanning device (1 1 ) for detecting the angular position of the separation chamber (2), when rotated by the drive unit (1 ), by sensing the marker segment (8') of the separation chamber (2),
- the scanning device comprising a light source (12') for irradiating light onto the segments (8) and a detector (14) for detecting light reflected by the segments (8), characterized in that the light source (12') and the detector (14) are arranged on a common carrier.
2. The centrifuge as claimed in claim 1 , wherein the common carrier is a circuit board providing electrical connections to both the light source (12') and the detector (14).
3. The centrifuge as claimed in claim 1 or 2, wherein the detector (14) is arranged in such a way that it detects light propagating in a direction essentially parallel to the direction of light generated by the light source (12').
4. The centrifuge as claimed in one of the preceding claims, wherein the marker segment (8') is configured in such a way that it reflects less light into the detector (14) than the other segments.
5. The centrifuge as claimed in one of the preceding claims, wherein the light source (12') comprises at least one LED and/or the detector (14) comprises at least one CCD chip.
6. The centrifuge as claimed in one of the preceding claims, further comprising a phase boundary detection device for determining the position of a phase boundary between blood components separated by means of the centrifuge, wherein the detector (14) of the scanning device (1 1 ) also realizes a detector of the phase boundary detection device, the phase boundary detection device further comprising an evaluation unit for evaluating a signal of the detector (14) for determining the position of a phase boundary.
7. The centrifuge as claimed in claim 6, wherein the phase boundary detection device comprises a light source (12") arranged in addition to the light source (12') of the scanning device (1 1 ).
8. A separation chamber for a centrifuge (100), in particular according to one of the preceding claims, the separation chamber (2) being insertable into a drive unit (1 ) of the centrifuge (100) and comprising:
- a plurality of segments (8) extending at least essentially parallel to a common plane;
- wherein at least one of the segments (8) is a marker segment (8') permitting the detection of the angular position of the separation chamber (2) when inserted into the drive unit (1 ) of the centrifuge (100), characterized by at least one light influencing structure (81 a, 81 b) integrally formed with the marker segment (8') such that light striking the marker segment (8') will be reflected by and/or transmitted through the separation chamber (2) differently than light striking one of the other segments (8), wherein the light influencing structure (81 a, 81 b) is formed in such a way that light radiated onto the light influencing structure (81 a, 81 b) along the rotational axis of the separation chamber (2) is absorbed or is transmitted or reflected along the rotational axis of the separation chamber (2).
9. The separation chamber according to claim 8, wherein the light influencing structure (81 a, 81 b) is integrally formed with a side wall (801 ') of the marker segment (8').
10. The separation chamber according to claim 9, wherein the light influencing structure (81 a, 81 b) is formed as a protrusion of the side wall (801 ') protruding away from an inner volume (80') of the marker segment (8').
1 1 . The separation chamber according to one of the preceding claims, wherein the light influencing structure (81 a) is configured for focussing light radiation (16).
12. The separation chamber according to claim 1 1 , wherein the light influencing structure (81 a) comprises a curved surface section (81 1 ).
13. The separation chamber according to one of claims 8 to 10, wherein the light influencing structure (81 b) is configured to reflect light radiation (16).
14. The separation chamber according to claim 13, wherein the light influencing structure (81 b) comprises a planar surface section (812) extending inclined relative to the common plane.
15. The separation chamber according to one of the preceding claims, wherein the common plane extends at least essentially perpendicular to a rotational axis (3) of the separation chamber (2).
PCT/EP2014/078122 2014-01-30 2014-12-17 Centrifuge and separation chamber for a centrifuge WO2015113700A1 (en)

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EP14153196 2014-01-30

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19515870C1 (en) * 1995-04-29 1996-08-14 Fresenius Ag Centrifuge controlled by laser beam scanner differentiates between fractions
EP0729790A2 (en) * 1995-02-03 1996-09-04 Fresenius AG Centrifuge
US6992278B2 (en) * 2002-04-08 2006-01-31 Gyros Ab Homing process
US20100160134A1 (en) * 2008-12-22 2010-06-24 Caridianbct, Inc. Blood Processing Apparatus with Digitally Controlled Linear Voltage Regulator for Optical Pulses

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0729790A2 (en) * 1995-02-03 1996-09-04 Fresenius AG Centrifuge
DE19515870C1 (en) * 1995-04-29 1996-08-14 Fresenius Ag Centrifuge controlled by laser beam scanner differentiates between fractions
US6992278B2 (en) * 2002-04-08 2006-01-31 Gyros Ab Homing process
US20100160134A1 (en) * 2008-12-22 2010-06-24 Caridianbct, Inc. Blood Processing Apparatus with Digitally Controlled Linear Voltage Regulator for Optical Pulses

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