A calibration arrangement for calibrating a detecting device

Abstract

A calibration arrangement (100) for calibrating a detection device (101), where the detection device comprises a detector for detecting a sample (102) doped with a fluorophore, said arrangement comprises an electromagnetic radiation source (105) for emitting electromagnetic radiation (106) at a wavelength, where the wavelength corresponds to wavelength of electromagnetic radiation emitted by the excited fluorophore of the sample. The arrangement comprises also a controller (107) for adjusting an intensity of the electromagnetic radiation (106) to correspond essentially to a desired minimum level of an intensity of the electromagnetic radiation (106) emitted by said fluorophore of the sample. The controller is also configured to detect the adjusted intensity by the detector (108) of the detection device and set said detected intensity as a threshold intensity so that only the intensities being at least at said threshold intensity is counted by the detection device when detecting the sample (102) in a sample flow (103).

Description

[0001] A CALIBRATION ARRANGEMENT FOR CALIBRATING A DETECTING DEVICE

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The invention relates to a calibration arrangement for calibrating a detecting device as well as to a method for the same. The detection device is for detecting a sample in a sample flow travelling in a conduit with a first speed during a fluorescence-guided surgery. The sample comprises at least one first fluorophore emitting electromagnetic radiation at a first wavelength and with a first intensity. The invention relates also to a calibration method for calibrating the detecting device.

[0004] BACKGROUND OF THE INVENTION

[0005] It is known that anatomical objects are operated in fluorescence-guided surgeries (FGS), where fluorescence-inducing photodynamic substances, such as 5-aminolevulinic acid (5-ALA), are increasingly used in surgical procedures for tumours, such as grade 3-4 gliomas, for example. Fluorescent markers and fluorophores, when excited at a certain wavelength, generate characteristic fluorescence that, for example, assist a surgeon in defining the infiltration zone between tumour cells and healthy tissue.

[0006] There are also devices known from prior art for detecting fluorescence of a sample obtained from the anatomical object during the fluorescence-guided surgeries, where the devices are used for guiding the operator whether the sample has tumour cell or healthy tissue. For example, the sample having one or more fluorophores emitting a characteristic electromagnetic wavelength represents a disease, whereas samples of health tissue do not have the fluorophores, whereupon no signals are detected.

[0007] WO20221 62277A1 discloses an exemplary device for detecting fluorescence of the sample obtained from the anatomical object during fluorescence- guided surgeries. The sample is transported away from the anatomical object via a conduit, and the possible fluorescence of the sample is determined. The device has one or more light sources to emit light towards the sample transported in the conduit, and one or more light receivers to detect possible fluorescence generated by one or more fluorophores carried by the sample. In the event, the sample has e.g. the tumour cell and has the fluorophore, it emits fluorescence, whereupon the device receives a signal from the light receiver, where the signal is proportional to the detected fluorescence by light receiver. Then the signal is compared to a predefined threshold and information indicating a comparison result is outputted.

[0008] The device described in WO2022162277A1 works very well, but there still exist needs for devices from the prior art, such as described in WO2022162277A1 , to verify the capability of the devices to detect fluorescence in different conditions, such as for example in situations where the samples are transferred with relatively high speed (up to or even over 100 m / s), or where the conduit or detection means might get dirty or contaminated.

[0009] SUMMARY OF THE INVENTION

[0010] An object of the invention is to alleviate and eliminate the problems relating to the known prior art. Especially the object of the invention is to provide a calibration arrangement and method for calibrating devices intended for detecting fluorescence from fast-flowing samples to verify the minimum detection threshold of fluorescence emission emanating from the said sample, and in particular during a fluorescence-guided surgery. The fastflowing samples may travel even up to 100 m / s or even more.

[0011] The features of independent claims can achieve the object of the invention.

[0012] The invention relates to a calibration arrangement for calibrating a detection device used for detecting a sample in a sample flow according to claim 1 , as well as to a detection device according to claim 12, said detection device comprising the calibration arrangement. In addition, the invention relates to a calibration method for calibrating the detection device used for detecting the sample in the sample flow according to claim 13.

[0013] According to the invention an intensity and speed of fluorescence from fastflowing samples can be simulated, and again a detection threshold for an actual use case can be set, such as e.g. in the fluorescence-guided surgery where chemically induced (doped) tumour tissues (fluorescent when excitated) are aspirated (fast-flowing) through a transparent surgical tube, or a conduit.

[0014] According to an example there is a continuous and constant rinsing or flow in the conduit, whereupon the samples are aspirated and transferred essentially continuously during the surgery. The continuous rinsing in the conduit alleviates possible blocks or clots, but the constant flow of rinsing also helps to ensure that the samples arrive essentially at a constant speed and do not stick to the walls of the conduit so easily. The rinsing also dilutes the blood left on the tissue, so the measurement is also very reliable because the blood does not cause light reflections or absorption of the excitation light into the blood. The rinsing is advantageously also used during calibration, whereupon the measurements but also the calibration take place under very similar conditions.

[0015] According to an embodiment of the invention a calibration arrangement is provided for calibrating a detection device, where the detection device is used for detecting a sample in a sample flow, which is conducted via a conduit with a first speed. It is to be understood that the first speed may vary and is in practice within a first speed range. In some embodiments it is necessary to just detect the existence of a sample, so whether there is a sample or not, regardless of an absolute concentration, but however, the current invention is not limited to this only. The sample is advantageously obtained from an anatomical object during fluorescence-guided surgeries, where a diseased sample has a fluorophore, and the device is used for detecting the fluorescence of the sample. The fluorophore is excited before the detection of the fluorescence. The excitation can be performed e.g. separately in the vicinity of the anatomical object by a suitable excitation device, and / or by the detection device having suitable excitation device, such as by an electromagnetic radiation emitted by an electromagnetic radiation source advantageously arranged before the detector(s).

[0016] It is to be noted that the conduit (e.g. a tube or pipe) itself is static and only the samples of tissue are flowing fast (up to 100 m / s or even more) inside the conduit. Thus, there is no need to take the sample to the conduit and after that to bring the conduit with the sample to a separate detection device. The same applies also to calibration.

[0017] The diseased sample may e.g. have a tumour cell carrying the fluorophore, whereupon the sample having the fluorophore emits electromagnetic radiation at a first wavelength, such as e.g. at 635 nm, depending on and characteristic of the used fluorophore. It is to be understood that the first wavelength may vary and is in practice within a first wavelength range or spectrum, such as between 600-650 nm, for example. In addition, it is to be understood that that sample may have more than one fluorophore, whereupon the sample also emits electromagnetic radiation at more than the first wavelength, or there might be more than one type samples each having specified fluorophore and thus emitted wavelength. In addition, the emitted electromagnetic radiation also has a certain intensity, depending, e.g. on the concentration of the fluorophore in the sample.

[0018] The detection device for detecting the samples comprises one or more detector for detecting the electromagnetic radiation(s) and wavelength(s) emitted by the excited fluorophore(s) of the sample. It is to be noted that the samples may have more than one fluorophore, whereupon also more than one electromagnetic radiation with one or more wavelengths might be emitted, depending on the used fluorophore. Sometimes two different fluorophores may emit the same wavelength. The detection device may have one detector, which can be able to detect different wavelengths, or the detection device may have more than one detector, in particular if there is need to determine the fluorophore emitted the particular wavelength. In addition, all the emissions might have their own intensities, correspondingly.

[0019] According to an embodiment of the invention, the calibration arrangement comprises a first electromagnetic radiation source for emitting electromagnetic radiation at least at the first wavelength, namely at the same first wavelength (Ai) as the first wavelength emitted by the fluorophore of the sample, wherein the first wavelength (Ai) is within the first wavelength range. According to an advantageous embodiment, the calibration arrangement comprises one or more electromagnetic radiation sources for emitting one or more electromagnetic radiation with one or more wavelengths corresponding to the wavelengths emitted by the used fluorophores. It is to be noted that more than one mutually different fluorophores can be used, which might emit different wavelengths. Thus, also more than one electromagnetic radiation sources for emitting more than one electromagnetic radiation wavelengths should be used. Alternatively, the electromagnetic radiation source may be configured to adjust wavelengths of the emitted electromagnetic radiation also in other ways known by the skilled person, and according to an example one source may emit different wavelengths or different wavelength ranges.

[0020] Also, the intensity of the electromagnetic radiation emitted by the electromagnetic radiation source can be adjusted. The electromagnetic radiation source can be implemented e.g. by a LED or the like, known by the skilled person of the suitable light sources. In addition, it is to be noted that the electromagnetic radiation in question is not necessarily visual or visible to the human eye, and the properties, such as intensity of the emitted electromagnetic radiation can be manipulated in ways know by the skilled person, such as limiting mechanically, like using filters or pinholes.

[0021] In addition, the calibration arrangement is configured to adjust an intensity of the electromagnetic radiation emitted by the electromagnetic radiation source(s) to correspond essentially to a desired minimum level of the intensity of the electromagnetic radiation(s) emitted by the fluorophore(s) of the sample, i.e. a threshold so that only the electromagnetic radiation(s) (or signals) with the intensity being at least at the threshold level or higher are detected. By this an unwanted noise is effectively cancelled. In addition, the threshold level (above observed signal baseline) ensures that possible noise in the signal does not affect positive detections.

[0022] The desired minimum level for the intensity for each fluorophore and thus electromagnetic radiations can be determined beforehand e.g. based on a visually defined level or by using a phantom tissue with the suitable fluorophore(s) and with the suitable concentration(s), whereupon the determined level of intensity can be used as the threshold level. Alternatively, or in addition to, also other methods can be used for determining the minimum levels for the intensities, such as observations of signal characteristics in preclinical studies and clinical operations.

[0023] During the calibration the adjusted intensity may be detected by the detector from the phantom, for example, and the detected level of the intensity is then used as the minimum threshold intensity level to the detector of the detection device for the wavelength in question. If more than one fluorophore or more than one wavelength is used, also more than one phantom can be measured, and corresponding intensities can be set or used as the threshold intensities to the detectors. It is to be noted that when calibrating the device, possibly higher intensity of the electromagnetic radiation emitted by the electromagnetic radiation source must be used, because the radiation attenuates when traveling through the wall of the tube from the radiation source to the detector, so that the intensity of the radiation is at the desired minimum level when measured by the detector being calibrated.

[0024] Therefore, after the calibration, the detection device (with one or more detectors) counts only samples emitting electromagnetic radiation having an intensity at least or over the threshold intensity.

[0025] According to an embodiment, also at least one detection window, or a time range or time frame, can be adjusted and set in the calibration of the detection device. The term "detection window" or “time frame11refers here to the time range or time minimum so that the sample is only counted if it exists for the detector in the detection window, i.e. a time needed by the sample to pass the detector falls within the set time range or is at least at the set minimum or more. The detection window (time [s]) depends on the speed the sample is transferred in the conduit and may be e.g. 1-5 milliseconds or the minimum level may be set e.g. to 1 millisecond, so if the signal is shorter than 1 millisecond, it is not counted. According to an embodiment, the range can also be used, whereupon if the signal is out the range, it is not counted.

[0026] The purpose of the detection window is to narrow down an examination area / time and enhance detection accuracy. In addition, according to an embodiment, if the signal is longer than 5 milliseconds, for example, it can be determined that the conduit may be blocked or contaminated e.g. by tissue fluid or the speed of the fluid flow is otherwise slowed down, and a corresponding indication can be presented to an operator, such as a request to clean the conduit, for example. Of course, there are also other alternatives for indications or actions to be done after signals occur outside the set detection window, such as, for example, ask a recalibration of the detection device.

[0027] It is to be understood there might be more than one detection window set to the detector or number of detectors and also so that detection windows depend on the different fluorophores used and thus for different samples, for example. In addition, e.g. sequential detectors may have different detection windows set. According to an embodiment, the detection window is set in the calibration process by emitting the electromagnetic radiation at a certain wavelength and a certain time (pulse width), the duration of which is essentially the time range or detection window, whereupon the duration is registered by the detection device to correspond the time range or the detection window.

[0028] According to an embodiment, the electromagnetic radiation is blinked or flickered (or the pulse width adjusted) so to simulate the speed of the flow of the samples inside the conduit and thus also the duration of fluorescence peak and signal and again the detection window. For example, by controlling a control frequency of a supply voltage of the electromagnetic radiation, the desired detection windows can be set for each detector of the detection device. In addition, the intensity of the electromagnetic radiation source can also be adjusted by adjusting the supply voltage and / or current of the electromagnetic radiation source thereby setting, e.g. the minimal threshold for the intensity.

[0029] According to an example, the calibration arrangement may have more than one electromagnetic radiation sources for emitting different wavelengths and / or dedicated for different detectors of the detection device. Thus, for example the detection device may comprise 6 detectors, whereupon the calibration arrangement comprises 6 electromagnetic radiation sources, correspondingly, and the calibration can be performed by controlling each electromagnetic radiation source separately and independently from each other, as well as also each detector can be calibrated separately and independently from each other. This is very advantageous, namely if e.g. only one detector needs to be recalibrated, it can be done simultaneously when the other detectors can still be used for actual determination of signals from the samples.

[0030] In addition, with the plurality of the detectors and electromagnetic radiation sources, the sequential electromagnetic radiation sources can be controlled (such as activated) sequentially imitating the speed of the sample in the conduit between the sequential detectors of the detection device. For example, if it is determined that with the normal speed of the sample flow the sample should travel from the first detector to the next second detector withing 1 millisecond, the second electromagnetic radiation source corresponding to the second detector is used to emit the electromagnetic radiation 1 millisecond after the first one. It is to be noted that a suitable time range can also be used here for setting the time needed by the sample to travel between the detectors.

[0031] Thus, in the calibration mode the sequential detection windows can be set to sequential detectors so that there are also time periods between the sequential detectors corresponding to time periods taken by the sample to travel with the flow in the conduit from the detector to the next detector. Thus, after the calibration the detection device can be set to count the samples or signals only if the signal is both a) at the wavelength (range) set, b) in the detection window set, c) intensity is at least at the threshold intensity or more, d) the signal is detected at least by two or more detectors and / or e) the time difference between the sequential detectors corresponds to the speed of the sample with the sample flow and set to the detector. The speed can be determined here also as a speed range, within which the speed can varied and still be valid for the determination, such as e.g. 20-100 m / s, or 40-60 m / s, as an example, and naturally also other speed ranges can be used.

[0032] It is to be understood that the detection device is advantageously in a calibration mode during the calibration, whereupon it sets the desired detection windows as well as intensities or other parameters to be calibrated based on the frequency of the blinked or flickered electromagnetic radiation, or the intensity used for determining the minimum threshold, for example. The calibration can be performed individually to each detector of the detection device or at the same time. In the embodiment, each detector may have own detection window, which can be equal or differing in time range.

[0033] Further, it is to be understood, that the electromagnetic radiation source and / or the detectors can be arranged into an inner surface of the conduit, whereupon there is no need for the radiation to pass through the wall. Alternatively, either the detector(s) or the electromagnetic radiation source, or both can also be located outside the conduit. However, even if the detectors were outside the conduit, the possible attenuation of other effect or interference of the conduit wall to the radiation can be and is taken into account during the calibration, because then also in the calibration the radiation passes the same conduit wall as in an actual operation of the detection device.

[0034] According to an embodiment, the calibration is performed before the operation of the detection device or whenever needed. In addition, the calibration arrangement may be arranged also so that the calibration is executable during the operation of the detection device, whereupon also possible contamination of the detectors during the measurements of the sample can be taken into account. Further, for example a new threshold intensity corresponding the desired minimum level can be set during the recalibration. The re-calibration is to be performed for example if the detector notices signal being too fast or over the detection window or also lots of samples with intensities below the threshold level.

[0035] The desired minimum level of the intensity can be determined and set in many ways, such as e.g. it can be set at the level observed in clinical analysis from real tissue. That is, the intensity of the electromagnetic radiation source to be used in the calibration is adjusted to correspond to the level found in the clinical analysis, which is above the signal disturbances or other noise. Alternatively, or in addition to, desired minimum level of the intensity can be determined by measuring a phantom comprising the used fluorophore and emitting electromagnetic radiation at the desired wavelength and with the intensity corresponding to the desired minimum level. As can be understood, more than one phantom and / or more than one fluorophore can be used in order to register more than one wavelength to be calibrated and measured during the actual operation of the detection device. In addition, all phantoms with their own fluorophores may emit their own intensity corresponding to the desired minimum levels. In practice, the electromagnetic radiation emitted by the phantom is measured by the detector (such as by the detector of the detection device), which can be used or accessed by the calibration arrangement so that the calibration arrangement can then use the measured minimum as an intensity level also for the electromagnetic radiation source to be used in the calibration.

[0036] The time range (or the detection window) can be set as described before in this document, so pulsing the electromagnetic radiation emitted by the electromagnetic radiation source of the calibration arrangement, where the pulse length represents the desired time range. Alternatively, or in addition to, the time range can also be adjusted by sending information representing the time range to the detection device (controller or the detection device), whereupon the detection device counts the signals only if the electromagnetic radiation radiates in the detection window of the detection device a time being within the time range or being at least or over the set minimum. According to an embodiment, the calibration arrangement can be integrated into a same unit with the detection device, i.e. the detection device may comprise the calibration arrangement, whereupon components of the detection device can be used, such as the detectors of the detection device can be used for measuring the phantom emissions so that the calibration arrangement can then use e.g. the intensity measured from the phantom by the detectors of the detection device as the minimum threshold intensity when controlling the intensity of the electromagnetic radiation source of the calibration arrangement during the calibration of the detection device.

[0037] In addition, the invention relates also to a calibration method for calibrating a detection device, wherein the detection device is used for detecting the sample (or existence of the sample) in the sample flow conducted via a conduit. The sample may travel with different speeds, but typically in the calibration mode a certain speed or speed range, namely first speed or first speed range is determined. The sample comprises fluorophore, which emits electromagnetic radiation at a first wavelength or at a first wavelength range. There might be more than one different type of samples with one or more fluorophores or also one sample may comprise more than one fluorophore, where fluorophores may emit either same wavelength (wavelength range) or different wavelengths (or wavelength ranges). Correspondingly, the detection device is configured to determine all the emitted wavelengths and samples, as well as the calibration device is configured to calibrate one or more detectors of the detection device for all of the emitted wavelengths (or ranges) and samples and speeds (or speed ranges) and intensities the samples are emitting the radiation.

[0038] According to an embodiment of the invention the method comprises steps of emitting electromagnetic radiation with least at the first wavelength Ai , said first wavelength Ai corresponding to the first wavelength emitted by the fluorophore of the sample, and detecting the electromagnetic radiation emitted by said first electromagnetic radiation source with a first detector of the detection device. In addition, the method comprises adjusting an intensity of said electromagnetic radiation emitted by said first electromagnetic radiation source to correspond essentially to a desired minimum threshold level of the intensity of said electromagnetic radiation at the first wavelength emitted by the fluorophore of the sample, and detecting said adjusted intensity by the first detector and setting said detected intensity as a threshold intensity to the detecting device (or at least to said detector) so that only the intensities being at least (or over) said threshold intensity is counted by the detection device when detecting the sample in the sample flow conducted via the conduit.

[0039] The method comprises advantageously also adjusting a first time range or minimum level of time that the sample (should) exists in a detection window of the detection device or the detector with the speed (or speed range) the sample is travelling. Again, if the detection time of the emission of the sample is too short, the signal is not counted. By this anomalous and other noise can be effectively decreased.

[0040] The present invention offers advantages over the known prior art, such as providing the calibrating method and arrangement for calibrating the devices for which the purpose is detecting fluorescence of the sample, the sample comprising one or more fluorophores, and the sample flowing fast inside the conduit. The speed of the sample is typically in the range of 20-100 m / s, but can be even more than 100 m / s. The present invention can be used especially for calibrating the detection devices for detecting fluorescence of the fastflowing sample comprising one or more fluorophores during a fluorescence- guided surgery.

[0041] In addition, the calibration mode can be used, whereupon the electromagnetic radiation source of the calibration arrangement is configured to emit electromagnetic radiation with one or more wavelengths with the intensity corresponding to the desired minimum threshold level, whereupon the calibration arrangement advantageously together with the detection device is configured to measure and set the intensities for the one or more wavelengths (or wavelength ranges) and for the one or more detectors of the detection device. Further, the electromagnetic radiation source of the calibration arrangement is configured to pulse the emitted electromagnetic radiations, where the pulse length corresponds to the desired minimum level of the detection window, whereupon the detection device is configured to measure and set the pulse length as the minimum for detection window for the one or more wavelengths (or wavelength ranges). This offers clear advantage, namely the calibration is very easy, accurate and fast and there is no need to any separate devices or arrangements, and the calibration can be used even during the operation. In addition, it is to be noted that there is no need to calibrate all detectors at the same time, but e.g. one detector can be calibrated first, then the second detector and so on sequentially until all the desired detectors are calibrated.

[0042] According to the invention, the fluorescent sample emission intensity (peak amplitude) and duration (time spent in the detection window) are matched with the calibration light source or with the electromagnetic radiation source or with the calibration arrangement. The electromagnetic radiation source of the calibration arrangement can be matched to any fluorescence intensity, including subvisual fluorescence, as well as also to the speed the sample is travelling with the fluid flow in the conduit. The fluorescence intensity can be easily simulated by adjusting the supply voltage of the electromagnetic radiation source. By adjusting the control frequency (rate of bl i n ki ng / fl ickeri ng ) of the electromagnetic radiation source, one can simulate the speed of the flow of the samples inside the tube so the duration of fluorescence peak in the detection window. The invention, therefore, is based on an adjustable electromagnetic radiation source that is able to simulate visual and subvisual fluorescence accurately, and the detection threshold for sample fluorescence can be set based on the calibration method according to the embodiments of the invention.

[0043] The exemplary embodiments presented in this text are not to be interpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" is used in this text as an open limitation that does not exclude the existence of also unrecited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated.

[0044] The novel features which are considered characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific example embodiments when read in connection with the accompanying drawings.

[0045] BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Next the invention will be described in greater detail with reference to exemplary embodiments in accordance with the accompanying drawings, in which: Figure 1 illustrates an exemplary detection device for detecting samples in a sample flow according to an advantageous embodiment of the invention,

[0047] Figures 2-3 illustrate exemplary calibration arrangements for calibrating the detection device for detecting samples in the sample flow according to an advantageous embodiment of the invention,

[0048] Figure 4 illustrates an exemplary principle for adjusting an intensity and the detection window according to an advantageous embodiment of the invention,

[0049] Figure 5 illustrates an exemplary detection device comprising the calibration arrangement according to an advantageous embodiment of the invention, and

[0050] Figure 6 illustrates an exemplary calibration method for calibrating the detection device for detecting samples in the sample flow according to an advantageous embodiment of the invention.

[0051] DETAILED DESCRIPTION

[0052] Figure 1 illustrates an exemplary detection device 101 for detecting samples 102 in a sample flow 103 based on fluorescence of the samples. The samples 102 are obtained from an anatomical object 114 during fluorescence-guided surgeries. The samples 102 are transported away from the anatomical object 114 via a conduit 104, and the possible fluorescence of the samples 102 are determined. The diseased sample has a fluorophore, as depicted elsewhere in this document, and the detection device 101 is used for detecting the fluorescence of the sample and thus the existence of the diseased sample. The fluorophores are excited before the detection of the fluorescence. The excitation can be performed e.g. separately in the vicinity of the anatomical object 114 by a suitable excitation device 115, and / or by the detection device 101 having suitable excitation device 116, such as by an electromagnetic radiation emitted by an electromagnetic radiation source advantageously arranged before the detector(s) 108.

[0053] Figure 2 illustrates an exemplary calibration arrangement 100 for calibrating the detection device 101 for detecting the samples 102 in the sample flow 103 according to an advantageous embodiment of the invention. The calibration arrangement 100 for calibrating a detection device 101 comprises a first electromagnetic radiation source 105, such as e.g. LED, for emitting electromagnetic radiation 106 at least at the first wavelength or the first wavelength range, wherein the first wavelength or the first wavelength range (Ai) corresponding to the first wavelength, or the first wavelength range emitted by the fluorophore of the sample 102. The detection device 101 comprises the first detector 108 for detecting electromagnetic radiation 106 emitted by the first electromagnetic radiation source 105.

[0054] The calibration arrangement 100 comprises also a controller 107, wherein the controller 107 is configured to adjust an intensity of the electromagnetic radiation 106 emitted by the first electromagnetic radiation source 105 to correspond essentially to a desired minimum level of the intensity of the electromagnetic radiation 106 at the first wavelength or the first wavelength range emitted by the fluorophore of the sample 102. The minimum level of the intensity is advantageously determined beforehand e.g. based on visually defined level or by using phantom tissue with a fluorophore, as is described elsewhere in this document.

[0055] The calibration arrangement 100 may comprise a mechanically adjustable pinhole 109 to control the intensity of the of the electromagnetic radiation 106 emitted by the first electromagnetic radiation source 105, or the electromagnetic radiation source 105 can be controlled by the controller to adjust the intensity. For example, electric current supplied to the electromagnetic radiation source 105 can be controlled by the controller.

[0056] The controller 107 is advantageously configured to detect said adjusted intensity by said first detector 108 and set the detected intensity as a threshold intensity to said detecting device 101 (or at least to said single detector 108) so that only the intensities being at least or over the threshold intensity is noticed by the detection device after the calibration when detecting the sample 102 in the sample flow 103 conducted via the conduit 104. In many applications the possible existence of the diseased samples, so samples with fluorophore, is sufficient. Thus, after the calibration the detection device 101 is configured to count only the samples 102, which emit electromagnetic radiation with the intensity at least or over the threshold intensity. The controller 107 is additionally configured to adjust a first time range or time minimum to the detecting device 101 or at least to a certain detector 108 that the sample should exist in a detection window 119 of the detection device 101 or the detector 108 with the speed or speed range it is assumed to travel in the conduit and pass the detector. The controlled 107 can adjust the time range e.g. by controlling the electromagnetic radiation source 105 to emit electromagnetic radiation at the first wavelength or first wavelength range a time (pulse width), the duration of which is essentially the first time range or the minimum level and the duration is registered by the detection device 101 to correspond the first time range or the minimum level of time the sample should exist in the detection window to be counted.

[0057] According to an embodiment the calibration arrangement 100 may also comprise additionally at least one second electromagnetic radiation source 110 and the detection device additionally at least one second detector 111 for detecting electromagnetic radiation emitted by said at least one second electromagnetic radiation source 110 correspondingly, whereupon the calibration arrangement 100 comprises own dedicated electromagnetic radiation source 105, 110 corresponding to each detector 108, 111 of the detection device 101 , as is depicted in Figure 2. However, the calibration arrangement 100 may also comprise only one electromagnetic radiation source, which is used for all detectors 108, 111 of the detection device 101 .

[0058] The controller 107 may be configured to control the emission of sequential electromagnetic radiation sources 105, 110 sequentially and so to correspond e.g. the speed (or speed range) of the sample in the conduit 104 between the sequential electromagnetic radiation sources 105, 110 and thus also between the corresponding detectors 108, 11 1 . In this way the calibration arrangement 100 may simulate the time took by the sample 102 travel from the detection window of the detector 108 to the sequential detection window of the next detector 111 in a downstream of the sample flow of the conduit 104. Again, it is to be noted that if the calibration arrangement comprises only one electromagnetic radiation source, the controller 107 can be configured to control the emission of the electromagnetic radiation source and at the same also to select a desired detector which is to be calibrated by the emission of the electromagnetic radiation source and which is used for measuring the emission of the electromagnetic radiation source for the calibration.

[0059] It is to be noted that the electromagnetic radiation sources and / or the detectors can be arranged into an outer surface of the conduit 104, as is the case in Figure 2, or into an inner surface of the conduit 104, as is the case in Figure 3 with the sources 105 and detectors 108. Alternatively, the sources and / or detectors can be arranged into an outer surface of the conduit 104, as is the case in Figure 3 with the source 1 10 and the detectors 111 , whereupon the wall 112 of the conduit locates between the electromagnetic radiation source 110 and the detector 111 . In both cases possible interactions, such as attenuation of the intensity of the electromagnetic radiation, is taken into account by the calibration arrangement.

[0060] Figure 4 illustrates an exemplary principle for adjusting an intensity and the detection window. The controller 107 is advantageously configured to control frequency of a supply voltage of the electromagnetic radiation source 105, 110 thus blinking or flickering the electromagnetic radiation source in a frequency simulating time taken by the samples travelling through the detection window, so i.e. simulating the duration 117 (pulse width) of fluorescence peak. In addition, the controller 107 is advantageously configured to control also the intensity 118 of the emission of the electromagnetic radiation source by adjusting a supply voltage and / or current of the electromagnetic radiation source. In the calibration mode the intensity is adjusted to correspond the threshold level.

[0061] In addition, it is to be noted that the calibration arrangement or the detection device may comprise a computing device 113, to which the first time range or time minimum level could be send, whereupon there is no need e.g. to blink the emission of the electromagnetic source, and whereupon the detection device and computing device counts the signals only if the electromagnetic radiation radiates in the detection window of the detection device a time being in said first time range or at least or over the set time minimum level.

[0062] Figure 5 illustrates an exemplary detection device 101 comprising the calibration arrangement 100 according to an advantageous embodiment of the invention, where the detection device 101 has a housing 118 to which the components of the calibration arrangement 100 are integrated.

[0063] Figure 6 illustrates an exemplary calibration method 200 for calibrating the detection device 101 for detecting samples 102 in the sample flow 103 according to an advantageous embodiment of the invention. In the step 201 the phantom is measured for determining at least the threshold for the minimum intensity. It is to be understood that this is just an example, and that the intensity threshold can be determined also in other ways as disclosed in this document and / or known by the skilled person.

[0064] Possibly also wavelength of the emitted radiation of the used fluorophore is determined. In step 202 the speed of the sample flow can be determined either by measuring for example the rinsing flow in the conduit or e.g. calculating or otherwise determining, like knowing by the skilled person or determined beforehand. The speed may also be the speed range at which the sample is imagined travelling during the operation. In step 203 the detection window is determined advantageously based on the speed or speed range so determining the time range the sample exist for the detector.

[0065] In step 204 the calibration parameters are adjusted to match the determined ones or otherwise selected parameters. For example, the intensity threshold or desired minimum level for the intensity is determined and converted to electromagnetic radiation source control parameter, such as control parameter related to voltage and / or electric current so to match the intensity emitted by the electromagnetic radiation source to the intensity threshold or desired minimum level for the intensity determined in step 201. In addition, parameters related to wavelengths of the used fluorophores can be taken into account, for example so that the electromagnetic radiation source is used to emit radiation essentially with the same wavelengths as measured from the phantom or determined otherwise.

[0066] Further, the speed or speed range is determined and converted to time range or minimum time the sample exists for the detector, and again to pulse width so the time the electromagnetic radiation source is emitting the wavelength.

[0067] In step 205 the detection device is set to a calibration mode. It is to be understood that all the detectors may be calibrated at the same, or only one or few single detectors are calibrated depending on the needs. In step 206 the electromagnetic radiation source is controlled to simulate the threshold intensity and / or the pulse width, where the pulse width corresponds to the desired detection window, as describes elsewhere in this document.

[0068] In the calibration mode the detection device is determining the electromagnetic radiation emitted by the electromagnetic radiation source, where the intensity of the emitted electromagnetic radiation corresponds to the minimum threshold intensity and the pulse width corresponds to the detection window. Possibly also other parameters can be detected, as described elsewhere in this document. In step 207 the measured parameters, such as intensity and pulse width, is set as threshold parameters to the detection device. Even if the detection device is described here, it is to be understood that that threshold parameters are set to one or more or all of the detectors of the detection device. The calibration is ended in step 208.

[0069] The above description only presents a few embodiments for a solution of the invention. The principle according to the invention can naturally be varied within the scope of protection defined by the claims, regarding for example implementation details and fields of use. In particular, it should be noted that for example the calibration arrangement may have only one electromagnetic radiation source and it can emit one or more wavelengths to one or more detectors, or the calibration arrangement may have more than one electromagnetic radiation source, such as one for each detector.

[0070] The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated.

Claims

Claims1. A calibration arrangement (100) for calibrating a detection device (101 ) for detecting a sample (102) in a sample flow (103) conducted via a conduit (104) with a first speed, said sample (102) comprising at least a first fluorophore emitting electromagnetic radiation at a first wavelength and with a first intensity, wherein the calibration arrangement (100) comprises:- a first electromagnetic radiation source (105) for emitting electromagnetic radiation (106) at least at said first wavelength, and- a controller (107), and wherein said detection device (101 ) comprises:- a first detector (108) for detecting said electromagnetic radiation (106) within a first time frame , wherein the controller (107) is configured to:- adjust an intensity of said electromagnetic radiation (106) emitted by said first electromagnetic radiation source (105) to correspond essentially to a desired minimum level of the intensity of said electromagnetic radiation (106) at the first wavelength emitted by said fluorophore of the sample, and- detect said adjusted intensity by said first detector (108) and set said detected intensity as a threshold intensity so that only the intensities being at least said threshold intensity is counted by said detection device when detecting the sample (102) in said sample flow (103) conducted via said conduit (104), whereupon, after the calibration- the detection device (101 ) is configured to count only samples (102) emitting electromagnetic radiation having the intensity at least or over the threshold intensity.

2. A calibration arrangement of claim 1 , wherein the controller (107) is additionally configured to adjust said first time range or time minimum that said sample is expected to be detectable by said detection device (101 ) with said first speed.

3. A calibration arrangement of any previous claims, wherein said first time range or the time minimum is adjusted by controlling said first electromagnetic radiation source to emit said electromagnetic radiation at said first wavelength a time, the duration of which is essentially said first time range or the minimumlevel and said duration is registered by the detection device to correspond said first time range or the minimum level.

4. A calibration arrangement of claim 3, wherein a control frequency of a supply voltage of said first electromagnetic radiation source is adjusted to blink or flicker the first electromagnetic radiation source in a frequency and / or with pulse width to simulate said first speed of the flow of the samples inside the conduit.

5. A calibration arrangement of any previous claims, wherein the intensity of said first electromagnetic radiation source is adjusted by adjusting a supply voltage and / or current of said first electromagnetic radiation source.

6. A calibration arrangement of any previous claims, wherein said calibration arrangement comprises additionally at least one second electromagnetic radiation source (110) and said detection device additionally at least one second detector (111 ) for detecting electromagnetic radiation emitted by said at least one second electromagnetic radiation source (110) correspondingly, and wherein each of the detector comprises own detection window, whereupon the calibration arrangement comprises own dedicated electromagnetic radiation source corresponding to each detector.

7. A calibration arrangement of claim 6, wherein the controller (107) is configured to control the emission of sequential electromagnetic radiation sources (105, 1 10) sequentially and so to correspond said first speed of the sample in said conduit between said sequential detectors (108, 111 ), and thus simulate the time took by the sample (102) to travel with from the detection window of the first detector (108) to the detection window of the next sequential detector (111 ) in a downstream of the sample flow in the conduit.

8. A calibration arrangement of any previous claims, wherein said electromagnetic radiation source (105, 110) and / or the detector (108, 111 ) is arranged into an inner surface of the conduit (104); or outer surface of the conduit (104), whereupon the wall (112) of the conduit locates between the electromagnetic radiation source (105, 110) and the detector (108, 111 ).

9. A calibration arrangement of any previous claims, wherein said calibration is executable during operation of the detection device and / or wherein the re-calibration is configured to be performed if the detector notices signal being too fast or over the detection window or intensities of a certainpercentages of the signals being below the set threshold level.

10. A calibration arrangement of any previous claims, wherein said desired minimum level of the intensity is determined by measuring a phantom and the determined level of intensity is then used as the threshold level..

11. A calibration arrangement of claim 1 , wherein said first time range is adjusted by sending said time range or time minimum level to a computing device (113) of the detection device and computing device counts the signals only if the electromagnetic radiation is determined within said first time frame or if the detection of the electromagnetic radiation lasts over the set time minimum level.

12. A detection device (101 ) for detecting a sample (102) in a sample flow (103) conducted via a conduit (104) with a first speed, said sample comprising a first fluorophore emitting electromagnetic radiation at a first wavelength and with a first intensity, wherein said detection device comprises the calibration arrangement (100) according to any of previous claims.

13. A calibration method (200) for calibrating a detection device (101 ), wherein said detection device is for detecting a sample (102) in a sample flow (103) conducted via a conduit (104) with a first speed, said sample (102) comprising a first fluorophore emitting electromagnetic radiation at a first wavelength and with a first intensity, wherein the method (100) comprises steps of:- emitting electromagnetic radiation (106) with least at said first wavelength, and- detecting said electromagnetic radiation (106) within a first time frame emitted by said first electromagnetic radiation source (105),- adjusting an intensity of said electromagnetic radiation (106) emitted by said first electromagnetic radiation source (105) to correspond essentially to a desired minimum level of the intensity of said electromagnetic radiation (106) at the first wavelength emitted by said fluorophore of the sample, and- detecting said adjusted intensity by said first detector (108) and setting said detected intensity as a threshold intensity so that only the intensities being at least said threshold intensity is counted by said detection device when detecting the sample (102) in said sample flow(103) conducted via said conduit (104), whereupon, after the calibration- only the samples (102) emitting electromagnetic radiation having the intensity at least or over the threshold intensity is counted by the detection device (101 ).

14. A calibration method of claim 13, wherein the method comprises adjusting said first-time range or the time minimum level that said sample expected to be detectable by said detection device (101 ).

15. A calibration method of any previous claims 13-14, wherein the method comprises determining said desired minimum level of the intensity by measuring a phantom and use the determined level of intensity as the threshold level..

16. A calibration method of any previous claims 14-15, wherein the first-time range or the time minimum level is determined by adjusting the pulse width of the emitted electromagnetic radiation to correspond to said first-time range or the time minimum level.

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