METHOD AND SYSTEM FOR MEASURING AND VERIFIING DRUG PORTIONS AND COMPUTER PROGRAM PRODUCT

Abstract

The present invention relates to a method for measuring and verifying drug portions, wherein the method avoids the need to train verification devices. According to the invention, a) characteristic data of a drug type are generated using a calibrated camera (1) of a measuring device (10), b) the characteristic data of the drug type are stored in a storage device (20), c) characteristic data are retrieved from or transferred to a verification device (30), and d) individual data for a drug portion to be verified are generated using a calibrated camera (31) of the verification device (30) and compared with characteristic data.For this purpose, a digital image of a drug portion to be verified is generated using a calibrated camera (31) and transferred to a control unit (32). The control unit (32) determines individual characteristic data for the drug portion to be verified based on known calibration parameters KP(VERI) of the camera (31) and the digital image. The control unit (32) compares the individual characteristic data with characteristic data of the corresponding drug type and verifies or rejects the drug portion based on the results of the comparison.

Description

[0001] The present invention relates to a method for measuring and verifying drug portions, a corresponding system comprising a measuring device, a storage device and a verification device, as well as computer program products.

[0002] Modern blister packaging machines, such as those disclosed in WO 2013 / 034504 A1, comprise, depending on the configuration, several hundred storage and dispensing stations for pharmaceuticals. Each storage and dispensing station contains multiple doses of a specific drug, and individual or multiple doses can be dispensed upon request. The blister packaging machine assembles and blisters the medications stored in the storage and dispensing stations according to the physician's prescribed dosage times, tailored to each patient.

[0003] To assemble the medication portions, appropriate storage and dispensing stations are activated to dispense one or more individual medication portions. When a storage and dispensing station is activated, a singulation unit separates a single medication portion and transfers it via a dispensing opening to a guide unit of the blister packaging machine. The guide unit then feeds the dispensed medication portion, possibly via an intermediate collection unit, to a packaging unit, which packages or blisters one or more medication portions according to the physician's instructions.

[0004] During blister packaging using the packaging machine, one or more drug doses are packaged into a blister pouch containing patient-specific information as well as information about the drug dose(s) within. This information can, for example, be printed on a special section of the blister pouch. The blister pouch itself is usually part of a blister tube that exits the blister packaging machine and is stored for further processing. This further processing of the individual blister pouches or the blister tube typically includes checking the blister pouches to verify the drug dose(s) contained within. This ensures that the drug dose(s) in each blister pouch are exactly as prescribed.The error rate regarding the dispensing of an incorrect medication is very low with modern blister packaging machines. However, since taking the wrong medication can have serious consequences for a patient, a follow-up check is an essential part of the blister pack production process.

[0005] To detect incorrectly filled blister packs, a blister tube can be passed through a control device. A user then verifies the correctness of the blister pack's contents, for example, by displaying an image of the pack to be inspected on a screen. Based on this image and a target composition also displayed on a screen, the user checks whether the contents match the specifications (i.e., the number of medication portions, their appearance, and, if applicable, shape correspond to the target composition). This process can also detect if medication portions were broken or damaged during the singulation process before being placed in the blister pack.

[0006] Manual inspection by a user is very time-consuming and costly. Therefore, automated inspection devices have been developed in which a preliminary check is performed automatically, and a user only needs to inspect a blister pack if the automated check yields ambiguous results. A corresponding inspection device is described, for example, in WO 2005 / 017814 A1. In the device disclosed in the aforementioned publication, a camera determines the number of drug portions in a blister pack and compares this to the number that should be in the blister pack to be verified, according to a specification. However, the inspection device disclosed in this publication only checks the drug portions with regard to their quantity. Incorrect drug portions cannot be detected as long as their number matches the specification.

[0007] In other known control devices, the characteristics of drug portions are determined using a camera image and appropriate software. This is disclosed, for example, in WO 2015 / 126254 A1, although in connection with drug portions before blister packaging. To identify individual drug portions, the characteristics (or images or image segments) determined from the camera image are compared with stored target values ​​(or images).

[0008] One disadvantage of the aforementioned inspection devices is that each system must be trained on the specific types of medication it is intended to verify before commissioning. This is because the cameras in each inspection system are arranged slightly differently and, due to variations in optics, produce slightly different images that deviate to varying degrees from the appearance of the actual medication portions, i.e., they recognize colors and shapes differently. Only through this training process can it be ensured that, despite these variations, the inspection device can correctly verify or identify the medication portions.

[0009] The object of the present invention is to provide a method and a system in which the need to train a device for verifying drug portions can be avoided.

[0010] The problem is solved according to the invention by a method for measuring and verifying drug portions according to claim 1. According to the invention, in step a), characteristic parameters of a drug type are first generated using a calibrated camera of a measuring device. Characteristic parameters of a drug type include, for example, the size or shape of a drug portion, the color of the drug portion, or its reflection pattern. Furthermore, it is also possible to capture the 3D profile of a drug portion of a drug type as characteristic parameters, for which special cameras are required. The drug portion can also be examined for damage, for example, based on the 3D profile.

[0011] The characteristic data are generated by using the calibrated camera to create at least one digital image of the drug portion and transferring this digital image to a control unit. The control unit then uses this digital image, an image processing program known from the prior art, and the known calibration parameters KP(MESS) of the camera to generate the characteristic data for the drug.

[0012] As mentioned at the outset, due to slight variations in, among other things, the camera optics and the camera's position relative to the object being imaged, each camera produces different digital images of the same object. Consequently, image processing programs would generate differing characteristic data based on these varying digital images. According to the invention, it is therefore essential that a calibrated camera is used to create the digital image of the drug portions, so that "normalized" characteristic data is generated by the measuring device. It is irrelevant which camera or which method is used for normalizing the camera, as long as the characteristic data accurately reflects the true characteristics of the drug, including, among other things, its correct size and color.Since certain variations in shape, size, and color always occur during the production of drug portions, several images are usually taken, from which several characteristic data points are determined, and from these, a range of characteristic data points is then defined. However, this is not explicitly mentioned in the application; that is, "characteristic data points" regularly refers to ranges of characteristic data points.

[0013] In step b), the characteristic data of the drug type are stored by the measuring device in a storage device. At least the aforementioned step a) is then repeated until the characteristic data of all desired drug types have been obtained. It will regularly be necessary to determine new characteristic data for new products or changes to drug dosages according to the above specifications. These are then stored or updated in the storage device.

[0014] In order to use the characteristic data generated by the measuring device for the verification of, for example, blister-packed drug portions, step c) provides that the characteristic data are retrieved from or transferred to a verification device.

[0015] The transfer to and from the storage device can be carried out using any data transmission method known from the prior art. For example, the storage device can be temporarily connected to the control unit of the surveying or verification device via a wireless or wired communication network. Alternatively, mobile data carriers such as USB sticks or hard drives can also be used for the transfer.

[0016] In step d), a calibrated camera of the verification device is used to generate individual characteristics for a drug portion to be verified and compared with characteristic characteristics of the drug type whose presence is to be verified. In the following, we will always refer to "one" drug portion. However, it is clear that a combination of several drug portions can also be verified, so the plural "drug portions" will always be included in the following.

[0017] Information regarding which drug portion(s) of which drug type(s) is / are to be verified must be provided to the measuring device. This can be done, for example, by using a data acquisition device to record data applied to a blister pack, with the data containing information about the drug types included, i.e., indicating the target composition. Alternatively, the verification device can be provided with the same data that was provided to the blister packaging machine for assembling the drug portions, so that the measuring device always knows which drug portion(s) of which drug type is / are to be verified.

[0018] To enable a comparison between individual and characteristic data, a calibrated camera of the verification device generates at least one digital image of a drug portion to be verified. This digital image is then transferred to a control unit, which uses known calibration parameters of the camera, the verification device, and the digital image to determine individual data for the drug portion. If a combination of several drug portions is to be verified, the individual data can be generated, depending on the camera and software used, from an image of all drug portions or from multiple images (each of a single drug portion).The individual characteristics are then compared by a control unit with characteristic characteristics of the corresponding type(s) of drug, and based on this.

[0019] Based on the comparison results, the drug dose is either verified or rejected. A drug dose is verified when its characteristic parameters match the individual parameters, taking into account predefined error limits.

[0020] Due to the use of a calibrated camera in both the measurement device and the verification device, and the provision of the generated characteristic data to a storage device accessible to both the measurement device and the verification device, it is possible to provide the characteristic data produced by a central measurement device to a large number of verification devices without the need to first train the verification devices for all the types of drugs they are to verify.The time-consuming, costly and error-prone process of "teaching" a verification device is eliminated by accessing existing characteristic data, which, as explained above, requires that both the creation of the characteristic data of the drug types and the creation of the individual characteristic data of the drug portions are carried out with calibrated cameras.

[0021] The aforementioned storage device can, for example, be part of an internal company network, so that the characteristic data can be transmitted to all verification devices connected to the company network using methods known to those skilled in the art. In a preferred embodiment, however, the characteristic data is stored in a storage device via a network, with the storage device being configured as cloud storage on the internet. By choosing cloud storage as the storage location for the characteristic data, this data can be made accessible to all users of verification devices worldwide at any time, provided that the verification devices include appropriately calibrated cameras for capturing a digital image of the drug portion(s) to be verified.

[0022] To ensure that the characteristic data can only be transmitted to or downloaded from verification devices that are compatible (i.e., have a calibrated camera), a preferred embodiment provides that the verification device transmits an authentication code to the storage device, the storage device checks this code, and only if the authentication code is valid can the characteristic data be retrieved from or transmitted to the verification device.

[0023] Due to changing manufacturing processes, it regularly occurs that, for example, the shape of the drug portions of a particular drug type changes. To ensure that the characteristic data for a drug type is always known when it was created, a preferred embodiment provides that the characteristic data is timestamped during its creation, indicating the date of its creation.If the characteristic data includes a timestamp, it is particularly preferred that the verification device, before comparing the characteristic data with the individual data of the drug portion to be verified, checks the timestamp of the characteristic data assigned to the individual data and, if a predetermined time difference t1 is exceeded, retrieves the characteristic data from the storage device and updates it internally. This prevents outdated characteristic data from being used for comparison.

[0024] As already indicated above, it may be necessary to verify not a single drug portion, but a collection of drug portions, which may include portions of different drug types. For example, it is conceivable that a blister pack whose contents need to be verified contains three or more drug portions of different drug types. According to the invention, verification takes place by generating individual characteristic data of drug portions arranged in, for example, a blister pack using an image processing program and the calibration parameters, and comparing these with the characteristic data of the drug types that are supposed to be in the blister pack.Due to the nature of the characteristic data, which only describe the external appearance of a drug portion, it cannot be ruled out that drug portions of different drug types may have identical characteristic data.To avoid erroneous positive verifications when verifying multiple drug portions of a composition, a preferred embodiment of the method according to the invention provides that, when verifying a composition of multiple drug portions, the control unit of the verification device checks the characteristic data assigned to the drug portions to be verified to determine whether all drug portions of the composition are uniquely verifiable, i.e., it checks whether identical characteristic data are present, in which case unique verifiability is not given.

[0025] As already explained, it is essential for the method according to the invention that the cameras of the measuring device and the verification device are calibrated, preferably using the same calibration method. For calibration, both so-called "internal" camera parameters, which relate to the lens properties of the camera and the relative arrangement of the lens and image sensor, e.g., CCD or CMOS sensor, and so-called "external" camera parameters, which relate to the geometric location, position, and orientation of the camera in space as well as the illumination, must be determined. The calibration parameters are derived from the aforementioned parameters. A multitude of different calibration methods have been described for calibrating a camera. An overview of these methods is given in the article by R. Gerdes et al., "Calibration of a digital image processing system with a CCD camera," tm - Technisches Messen 60 (1993) 6 and 60 (1993) 7 / 8.Oldenbourg Verlag, where classic approaches to calibration procedures are described.

[0026] Preferably, the calibration parameters KP(MESS), KP(VERI) of the cameras of the surveying and verification device are generated by creating digital images of a plurality of calibration objects with the cameras and comparing these with characteristic data of the calibration objects to generate the calibration parameters KP(MESS), KP(VERI).

[0027] The aforementioned problem is further solved by a system for measuring and verifying drug portions according to claim 8. The system according to the invention comprises a measuring device, comprising means for generating characteristic data of a drug type by performing step a) according to the aforementioned method, a storage device, comprising means for storing the characteristic data by performing step b) of the aforementioned method, and a verification device, comprising means for generating individual data for a drug portion to be verified and for comparing the individual data with characteristic data by performing steps c) and d) according to the method according to the invention.

[0028] The invention further relates to a computer program product comprising commands that cause the measuring device of the system to create characteristic data for a type of drug by performing steps a) and b) according to the method according to the invention and to store them in a storage device.

[0029] Finally, the invention relates to a computer program product comprising commands that cause the verification device of the system to create individual characteristic data for drug portions to be verified by performing steps c) and d) according to the method according to the invention and to compare them with characteristic data.

[0030] The present invention will now be described with reference to preferred embodiments and the drawing in which Figure 1 represents a flow chart of a preferred embodiment of the method according to the invention; Figure 2The process of generating characteristic data and comparing it with individual data is schematically illustrated; Figure 3 a schematic representation of an embodiment of the system according to the invention; Figure 4 shows a blister tube with a plurality of blister bags; Figure 5 illustrates the comparison and verification of individual and characteristic data; Figure 6 which schematically illustrates the calibration process; and Figure 7 The schematic illustrates the generation of a calibration parameter.

[0031] Figure 1Figure 1 shows a flowchart of a preferred embodiment of the inventive method for measuring and verifying drug portions. In a first step 100, a digital image of a drug portion of a given drug type is created using a calibrated camera of a measuring device. As mentioned previously, in practice, it is common practice to generate multiple images, which are then subjected to the subsequent process steps, so that rather than point-like characteristic data, areas are created. This is assumed below but not described in detail. In a step 110, the digital image is transferred to a control unit of the measuring device.The control unit can be an integral part of the aforementioned camera, but it can also be, for example, a standard PC that can be controlled by a user via a screen. Data transmission can be wireless or wired, using transmission methods known to those skilled in the art. In step 120, characteristic data for a drug portion of a given drug type are generated based on the digital image and taking into account known calibration parameters of the camera of the measuring device. These data may include, for example, the size, shape, and color of the drug portion. According to the aforementioned process steps 100-120, characteristic data for all drug types are generated and subsequently verified.

[0032] In step 200, the characteristic data are stored in a storage device. This can be done at any time; that is, the characteristic data can be stored immediately after creation or only after all drug types to be verified have been processed. The type of storage device is not essential for the present invention. The transmission of the characteristic data can be wired or wireless; it is also conceivable to transfer the characteristic data to a portable data carrier, such as a USB stick or a hard drive. Preferably, the storage device is designed as cloud storage that is accessible worldwide at any time, so that the characteristic data is available to a third party anywhere at any time.

[0033] In step 300, the characteristic data is retrieved from or transmitted to a verification device. This retrieval or transmission can also be wireless or wired. Here too, it is conceivable that the storage device is (temporarily) connected to the verification device for data transfer.

[0034] The following process steps of the preferred embodiment of the method according to the invention are described with reference to a single drug portion, but also apply accordingly to a combination of several drug portions. In step 400, a digital image of a drug portion to be verified is generated using a calibrated camera of a verification device. In step 410, the digital image is transferred to a control unit of the verification device, whereby the provisions described in relation to step 110 apply accordingly. In step 420, individual characteristic data of the drug portion to be verified are created with the aid of appropriately designed image processing software and based on the known calibration parameters of the camera of the verification device.In step 430, the previously created individual characteristics of the drug portion to be verified are compared with the characteristic characteristics of the type of drug that the verification device "expects" in, for example, a blister pack - i.e., the type of drug that should have been blister-packed by the blister machine according to specifications.

[0035] If the deviations between the individual characteristics and the characteristic characteristics do not exceed certain predetermined limits, the drug dose is positively verified, i.e., it is confirmed that the drug dose is a drug dose of the type of drug expected by the verification device.

[0036] Figure 2Figure 1 schematically shows how characteristic data for a drug type are generated, transferred to a storage device, and compared with individual data. The digital images DAB1 - DABx are analyzed using image processing software, and the characteristic data CKD1 - CKDx are generated based on the calibration parameters KP(MESS) of the camera of a measuring device 10. As mentioned above, the characteristic data typically consist of multiple value ranges that reflect manufacturing tolerances in the production of drug portions of the various drug types. The characteristic data CKD1 - CKDx are transferred to a storage device 20 and from there to a verification device 30.

[0037] The verification device uses a calibrated camera to create digital images DAB1* and DAB2* of the drug portions to be verified. Using image processing software and a method known to those skilled in the art, and taking into account the calibration parameters KP(VERI) of the camera, individual characteristic data IKD1* and IKD2* are generated for the drug portions to be verified. These individual characteristic data IKD1* and IKD2* are compared with the characteristic data CKD1 and CKD2 of the drug types expected by the verification device's control unit. The drug types and drug portions expected are communicated to the verification device beforehand, for example, by reading this information from a blister pack to be examined.Based on a comparison of the individual characteristics with the characteristic data, a decision is then made, taking into account specific requirements, as to whether the drug portions correspond to the drug portions that were expected.

[0038] Figure 3Figure 1 shows a schematic representation of a system for measuring and verifying drug doses. The upper section shows two views of the measuring device 10: a side view in the upper section and a top view in the lower section, with only the "left" sections, containing the camera, varying. The measuring device comprises a camera 1, which is connected via a line 6 to a control unit 2, which in turn is connected via a line 7 to a display unit 3. A drug dose 50 of a specific drug type, to be measured, is arranged on a tray 4 below the camera 1. The camera 1 is at a predetermined distance H1 from the surface of the tray, this distance corresponding exactly to the distance the camera had from the tray during its calibration (the so-called external calibration parameter).In the illustrated embodiment, the control unit 2 is connected via a communication link 8 to a storage device 20, which in this embodiment is configured as cloud storage and is part of the schematically indicated internet 21. The wired and wireless transmission methods necessary for transmission via the internet are known to those skilled in the art, so a detailed description is omitted.

[0039] The storage device 20 is connected to a control unit 32 of the verification device 30 via a (temporary) communication link 25. The control unit 32 is connected to a display unit 33 via a line 37 and to a camera 31 via a line 36. Furthermore, the control unit 32 is coupled to a detection unit 35. In the illustrated embodiment, the camera 31 is arranged above a blister tube consisting of several blister packs. The blister tube is wound onto a reel 38 and is moved "to the right" onto the reel 39 to verify the drug portions in the individual blister packs. For this purpose, the reel 39 is driven by a motor (not shown). The camera 31 generates a digital image of the drug portion(s) in a blister pack and transmits it to the control unit 32 via line 36.Using the recording device 35, data printed on the blister packs 41 is read out, which indicates, among other things, which drug portion(s) should be arranged in the individual blister packs.

[0040] Figure 4 Figure 1 shows a schematic representation of a blister tube 40 with four blister packs 41a - 41d and drug portions 51, 52 arranged in them. In the upper section, each blister pack includes a data section 42a - 42d, on which (not shown) information about the drug portions or types to be arranged in the blister pack is printed.

[0041] Figure 5This schematically illustrates the verification of drug portions. The top row shows individual characteristics IKD1–IKD4 relating to the shape of the drug portions, depicting the shape of the drug portions contained in the blister packs. The row below shows the characteristic CKD1–CKD4 relating to the shape of the drug portions or types expected by the verification device in the blister packs. The bottom row shows... Figure 5 The result of the verification is illustrated. The individual identifiers IKD1 and IKD2 are positively verified, IKD3 and IKD4 negatively.

[0042] Figure 6This figure roughly illustrates how camera 1 of the measuring device is calibrated; the same applies to the camera of a verification device. During calibration, several calibration objects, of which only one, KO1, is shown, are placed under the camera, and a digital image of the calibration objects is generated. Using image processing software, characteristic parameters for the measured calibration object are created, and these parameters are used to determine whether and to what extent the image generated by the camera deviates from the actual appearance of calibration object KO1.

[0043] In Figure 7 This is shown schematically for the characteristic parameter "size", whereby this representation is very simplified and is only intended to illustrate the principle. In the middle of Figure 7The results of the image processing for calibration object KO1 are visually represented with respect to the characteristic parameter "size". Based on the size differences, it is evident that the size of the object as represented digitally does not correspond to the "true" size of calibration object KO1. In the illustrated case, the size of the object as represented digitally is only 75%, whereas such a deviation does not occur in reality. Due to this deviation, a calibration factor of 1.25 is required for camera 1 with respect to the characteristic parameter "size". This means that the parameters determined by the image processing software must be adjusted using this calibration parameter to obtain the "true" characteristic value "size".

Claims

1. A method for measuring and verifying drug portions, wherein a) characteristic data of a drug type are generated using a calibrated camera (1) of a measuring device (10) by: generating at least one digital image of a drug portion (50) of a drug type with the calibrated camera (1) of the measuring device (10), transferring the generated digital image to a control unit (2), and generating characteristic data for the drug type by the control unit (2) using known calibration parameters KP(MESS) of the camera (1) of the measuring device (10) and the digital image, b) storing the characteristic data of the drug type in a storage device (20), c) retrieving or transferring the characteristic data to a verification device (30).d) Individual characteristics for a drug portion to be verified are created using a calibrated camera (31) of the verification device (30) and compared with characteristic characteristics by: generating at least one digital image of a drug portion to be verified using a calibrated camera (31) of the verification device (30), transferring the generated digital image of the drug portion to be verified to a control unit (32), the control unit (32) determining individual characteristics for the drug portion to be verified using known calibration parameters KP(VERI) of the camera (31) of the verification device (30) and the digital image, and the control unit (32) comparing the individual characteristics with characteristic characteristics of the corresponding drug type and verifying or rejecting the drug portion based on the results of the comparison.

2. Method for measuring and verifying drug portions according to claim 1, characterized by the fact that the characteristic data are stored via a communication link (8) in a storage device (20) which is designed as cloud storage on the Internet (21).

3. Method for measuring and verifying drug portions according to claim 1 or 2, characterized by the fact that The verification device (30) transmits an authentication code to the storage device (20), the storage device (20) checks this code, and only if it is valid are the characteristic data retrieved from or transmitted to the verification device (30).

4. Method for measuring and verifying drug portions according to one of claims 1-3, characterized by the fact that When creating the characteristic data, these are given a timestamp.

5. Method for measuring and verifying drug portions according to claim 4, characterized by the fact that The verification device (30) checks the timestamp of the characteristic data assigned to the individual characteristics before comparing the characteristic data with the individual characteristics of the drug portion to be verified and, if a predetermined time difference t1 is exceeded, retrieves and updates the characteristic data from the storage device (20).

6. Method for measuring and verifying drug portions according to any one of claims 1-5, characterized by the fact that When verifying a combination of several drug portions, the control unit (32) of the verification device (30) checks the characteristic data assigned to the drug portions to be verified to ensure that all drug portions in the combination can be uniquely verified.

7. Method for measuring and verifying drug portions according to any one of claims 1-6, characterized by the fact that the calibration parameters KP(MESS), KP(VERI) of the cameras (1; 31) of the measuring and verification device (10; 30) are generated by creating digital images of a plurality of calibration objects KO with the cameras and comparing these with characteristic data of the calibration objects to generate the calibration parameters.

8. A system for measuring and verifying drug portions, comprising a measuring device, comprising means for generating characteristic data of a drug type by performing step a) according to any one of claims 1-7, a storage device (20), comprising means for storing the characteristic data by performing step b) according to any one of claims 1-7, and a verification device (30), comprising means for generating individual characteristics of a drug portion to be verified and for comparing the individual characteristics with characteristic data by performing steps c) and d) according to any one of claims 1-7.

9. Computer program product comprising commands that cause the measuring device (10) of the system according to claim 8 to create characteristic parameters of a drug product by performing steps a) and b) according to any one of claims 1 - 7 and to store them in a storage device (20).

10. Computer program product comprising commands that cause the verification device (30) of the system according to claim 8 to create individual characteristic data for a drug portion to be verified by performing steps c) and d) according to any one of claims 1 - 7 and to compare them with characteristic data.