Inspection method for medical containers

Abstract

The present invention relates to a method for inspecting a medical container (100) made of a light-transmitting material, the method comprising scanning a portion (110) of the medical container (100) to be inspected with white light emitted from a white light confocal system (20), detecting light reflected from the portion (110) of the medical container (100) by the white light confocal system (20), and determining whether particles are present in or on the portion (110) of the medical container (100) based on inspection results obtained by the white light confocal system (20).

Description

[Technical field]

[0001] The present invention relates to a method for inspecting medical containers, and more particularly to a method for detecting the presence of particles in or on a portion of a medical container. [Background technology]

[0002] Medical containers should be as free of contaminants as possible. For example, if particulates are present in or on the interior surfaces of the medical container that define the interior volume of the container, the particulates may cause contamination of the medical product stored in the medical container or cause injury to a user into whom the medical product is injected. However, even with extreme caution, it is not always possible to prevent particles, such as foreign particles generated during the manufacturing process of the medical container or attached to the medical container.

[0003] A visual inspection is performed to avoid possible contamination due to the presence of particles. However, visual inspection can generally only identify particles 300 μm or larger. Optical or digital microscopy can optionally be used to find particulates. However, microscopic examination tends to require significant resources and is therefore not suitable for large-scale inspection. Furthermore, close examination of particles by microscope may require extraction of the container and liquid, followed by observation of the particles on a filter. It is therefore a destructive inspection method, limiting the possible scope of application.

[0004] It may also be desirable to obtain geometric information of particles in three dimensions (3D). Microscopy, or camera inspection, is only capable of producing particle information in two dimensions (2D).

[0005] White light confocal technology is known as a non-destructive, non-contact sensing process for determining the thickness or surface roughness of transparent objects. It is also known to apply white light confocal technology for particle observation. For example, US Pat. No. 5,399,433 discloses white light confocal imaging for generating a topographical representation of the surface of a medium on which clusters of biological particles may be cultured. US Pat. No. 5,499,433 describes an optical device for use in the measurement of size, amount and / or presence or velocity of particles in a fluid or gas, or in a depth measurement method.

[0006] White light confocal sensing involves passing white light through a diffractive lens to impart chromatic aberration (chromatic aberration along the optical axis) and directing the light through an objective lens to the measurement object. The light reflected from the measurement object is directed to an optical pinhole, allowing only the light beam focused on the object to pass. Due to the chromatic aberration, the focal position of the light beam along the optical axis is wavelength dependent. Therefore, by monitoring the wavelength of the reflected light, the distance to the measurement object can be determined. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US Patent Application Publication No. 2013 / 0084598 [Patent Document 2] European Patent No. 2503376 Summary of the Invention

[0008] In view of the above problems in inspecting medical containers, it is an object of the present invention to implement a method for inspecting medical containers.

[0009] According to the present invention there is provided a method as defined in the accompanying claims.

[0010] Specifically, a method for inspecting a medical container made of a light-transmitting material is provided, the method comprising scanning a portion of the medical container to be inspected with white light emitted from a white light confocal system, detecting light reflected from the portion of the medical container by the white light confocal system, and determining whether a particle is present within or on the portion of the medical container based on inspection results obtained by the white light confocal system.

[0011] The medical container may have a cylindrical shape, and the method further comprises rotating the medical container about a central axis of the medical container during scanning to perform inspection of a portion of the medical container at different locations along a circumference of the medical container.

[0012] The medical container can have a longitudinal shape, and the method further comprises moving the white light confocal system relative to the medical container during scanning to perform inspection of a portion of the medical container at different positions along the longitudinal direction of the medical container.

[0013] The white light confocal system used in the method of the present invention comprises a 2D sensor, and the scanning and detection are performed by the 2D sensor, further comprising generating a 2D image of a portion of the medical container, indicating the presence or absence of a particle, and a determination is made based on the 2D image.

[0014] If at least one particle is determined to be present, the method may further comprise counting the number of particles on the 2D image.

[0015] The white light confocal system used in the method of the present invention further comprises a 3D sensor, and when it is determined that at least one particle is present, the method further comprises scanning a portion of the medical container containing the particle with white light emitted from the 3D sensor of the white light confocal system, detecting light reflected by the portion of the medical container by the white light confocal system, and obtaining 3D geometric information of the portion of the medical container containing the particle based on the detection result obtained by the white light confocal system.

[0016] The method further comprises generating a 3D image of the portion of the medical container, the 3D image including geometric information of the particles.

[0017] In the methods of the present invention, scanning can be performed with light substantially orthogonal to a portion of the medical container.

[0018] The method can be performed using a system that includes a white light confocal system configured to determine whether a particle is present in or on a portion of a medical container.

[0019] The system may further include a holder configured to rotatably hold the medical container, and a rotational drive configured to rotate the medical container on the holder.

[0020] The system may further include a linear drive configured to move the white light confocal system relative to the holder.

[0021] The white light confocal system can include a 2D sensor and can be configured to generate a 2D image of a portion of the medical container and can be configured to determine at least one of the following on the 2D image: a position of each particle; and a dimension of each particle.

[0022] The white light confocal system can include a 3D sensor and can be configured to acquire 3D geometric information of a portion of the medical container that contains the particle.

[0023] The white light confocal system can be configured to generate a 3D image of a portion of a medical container containing the particle.

[0024] The method of the present invention allows for reliable and efficient detection, counting, and / or measurement of any particles present in and / or on a portion of a medical container. In cases where a thorough inspection is required, including measurement of any particles found, the present invention can also provide time-efficient geometric measurement of particles in three dimensions. [Brief description of the drawings]

[0025] Embodiments of the invention will now be described in further detail with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a schematic diagram of an inspection system according to one embodiment. [Diagram 2] FIG. 1 illustrates a white light confocal system used for inspection of medical containers according to an embodiment. [Diagram 3] FIG. 1 shows signal intensity versus wavelength of light detected by a white light confocal system. [Figure 4] FIG. 1 shows a 2D image produced by a white light confocal system showing the presence of particles. [Diagram 5] FIG. 13 shows measurement results indicating the height of detected particles. [Figure 6] FIG. 13 shows a 3D graphic representing geometric information of the interior surface of a medical container containing detected particles. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The present invention uses white light confocal technology to detect, count, and / or measure particles that may be present in and / or on a portion of a medical container.

[0027] At present, the white light confocal technique is widely known to those skilled in the art and is mainly used to measure the distance to an object, the thickness of an object, and / or the roughness of the surface of an object. There have been no reported cases of applying this technique to detect the presence of potential particles in and / or on a portion of a medical container. Particles that can be detected by the present invention include, but are not limited to, glass, plastic, or cotton particles, as well as foreign particles such as medical product agglomerates. Particles may be generated during the manufacturing process of the medical container, and foreign particles may be attached during the manufacturing process of the medical container.

[0028] 1 illustrates a schematic diagram of an inspection system 10 according to an embodiment. In the illustrated embodiment, the inspection system 10 is used to perform inspection of medical containers, such as glass syringes 100.

[0029] Syringe 100 has a generally longitudinal shape extending along its longitudinal axis, which may define an X-axis. Syringe 100 includes a hollow cylindrical barrel 102 extending along the longitudinal axis, a tip portion 104 to which an injection needle may be attached, and a flange portion 106 that holds syringe 100 during injection. Cylindrical barrel 102 defines an interior cavity into which a plunger (not shown) may be pushed toward or pulled away from tip portion 104 to perform an injection.

[0030] Here, a glass syringe 100 is shown as an example of the object to be inspected. However, other medical containers can be inspected by the present invention in a similar manner, regardless of their size, shape and use, as long as they are made of a light-transmitting or non-opaque material. The material can be transparent or translucent, preferably glass, but also plastic.

[0031] As shown in FIG. 1, the inspection system 10 includes a white light confocal system 20 for performing an inspection of a syringe 100, and a holder 12 for rotatably and translatably holding the syringe 100 during inspection.

[0032] The syringe 100 can be rotated on the holder 12 about the central axis of the barrel 102 by a rotational drive 50. The rotational drive 50 can be any known rotational drive. The holder 12 can be configured to be movable along the X-axis together with the syringe 100.

[0033] The white light confocal system 20 includes a sensor head 22 and a controller 30 coupled together via an optical cable 24 .

[0034] The optical cable 24 may include an optical fiber bundle. The controller 30 further includes a light source 32 and an optical system 34, a two-dimensional (2D) data processing unit 36, and optionally a three-dimensional (3D) data processing unit 38.

[0035] Although not shown, the control device 30 includes a computer configured to perform data processing necessary for inspecting the syringe 100. The control device 30 thus includes a processor for performing various calculations, a random access memory (RAM) for temporarily storing sensing devices or data or information obtained by the calculations, a read-only memory (ROM) for storing operating software, and a non-volatile memory for storing parameters, look-up tables, programs for controlling the operation of the sensor head 22 to scan the intended area of ​​the syringe 100, and programs necessary to perform image processing to detect, count, and / or measure particles based on the obtained information, etc.

[0036] The light source 32 may be any known illumination device configured to emit light, such as polychromatic light or white light, preferably white light. The optical system 34 may also include an optical device for transmitting the light emitted by the light source 32 to the sensor head 22 via the optical cable 24. The optical system 34 may also include an optical device for transmitting the light received by the sensor head 22 to the 2D data processing unit 36 ​​and the 3D data processing unit 38. It can also include:

[0037] The sensor head 22 comprises a 2D sensor 26 and a 3D sensor 28. The 2D sensor 26 and the 3D sensor 28 may be provided in the same sensor head 22. For ease of reading, only one 2D sensor 26 and one 3D sensor 28 are illustrated in Fig. 1. Alternatively, the 2D sensor 26 and the 3D sensor 28 may be provided in separate dedicated sensor heads.

[0038] The 2D sensor 26 is configured to scan a portion of the syringe 100 to be inspected with white light and receive light reflected by the portion of the syringe 100. The reflected light is then transmitted to the 2D data processing unit 36. The 3D sensor 28 is configured to scan a portion of the syringe 100 where particles are detected based on the 2D data processing and receive light reflected by the portion of the syringe 100. The reflected light is then transmitted to the 3D data processing unit 38.

[0039] Each of the 2D sensor 26 and the 3D sensor 28 may include an optical lens (not shown), such as a diffractive lens, for imparting chromatic aberration to the white light from the light source 32. The sensor head 22 may also include an objective lens (not shown) for directing the light beam LB emitted from the sensor head 22 to a measurement object.

[0040] In accordance with the present invention, the light beam LB is directed at a portion of the syringe 100 that is scanned for inspection. In one embodiment, the inner surface 110 of the syringe 100 may be scanned for inspection, as shown in FIG. 2. In another embodiment, the outer surface 112 of the syringe 100 may also be scanned for inspection. In yet another embodiment, any point within the syringe 100 that extends between the outer surface 112 and the inner surface 110 may also be scanned.

[0041] Due to the chromatic difference, the light beam LB has, depending on each wavelength, a different focal position along its optical axis, which may be defined by the Z-axis. In FIG. 2, for ease of reading, only the light beam LB focused on the measurement point M on the inner surface 110 of the syringe 100 is shown. Thanks to the confocal configuration, only the light beam LB reflected by the measurement point M on the inner surface 110 is collected and transmitted in the optical cable 24 and then to the optical system 34 of the control device 30. The other light beams that do not have a focal point on the measurement point M on the inner surface 110 of the syringe 100 are not collected by the sensor head 22.

[0042] 1, the sensor head 22 may be configured to move along the barrel 102 of the syringe 100, i.e., along the X-axis. A linear drive 60 may be used to move the sensor head 22 along the entire length of the barrel 102. This configuration may ensure that testing is performed over the entire length of the barrel 102. Alternatively, or additionally, the holder 12 may be configured to be movable with the syringe 100 relative to the sensor head 22 to enable testing over the entire length of the barrel 102. Additionally, the rotary drive 50 may move the syringe 100 relative to the sensor head 22 to enable testing over the entire circumference of the barrel 102.

[0043] FIG. 3 shows signal strength versus wavelength of light detected by confocal chromatic difference system 20. The signal strength has a maximum value for wavelength λ. The light beam of wavelength λ has a focus on inner surface 110 of syringe 100, or at measurement point M in FIG. 2. The relationship of focus position versus a particular wavelength and distance to a measurement target can be pre-determined. Based on the pre-determined relationship, the wavelength of reflected light with the highest signal strength can be monitored to determine the distance to measurement point M on inner surface 110 of syringe 100.

[0044] The 2D data processing unit 36 ​​is configured to obtain the measurement results based on the light reflected from the measurement object via the 2D sensor 26 and generate a 2D image of the measurement object. The 2D image can be used to calculate the dimensions of the particle on the 2D image, for example the length or width of the particle. The length here refers to the dimension of the particle along its longitudinal direction on the 2D image, for example the dimension of the particle along the X-axis. The width here refers to the dimension of the particle along a direction perpendicular to its longitudinal direction on the 2D image, for example the dimension of the particle along the Y-axis. The 2D image lacks height (or thickness) information of the particle. The height can be defined in a direction perpendicular to the direction in which the length and width are defined. The height can also be defined as the dimension of the particle along the Z-axis.

[0045] 4 is a 2D image generated by the confocal color difference system 20 based on data obtained by the 2D sensor 26 and the 2D data processing unit 36 ​​according to this embodiment. The 2D image in FIG. 4 represents the inner surface 110 of the syringe 100 over the entire circumference (i.e., 360° around the center) and a total length of 1.0 cm along the longitudinal direction (X-axis) of the syringe 100. As shown, the 2D image displays the presence of a particle P on the inner surface 110, as highlighted by the circle and arrow in FIG. 4.

[0046] The 3D data processing unit 38 is configured to obtain the measurement result based on the light reflected by the measurement object via the 3D sensor 28 and obtain the 3D geometric information of the measurement object, i.e. the width, length and height of the particle. Figure 5 shows the measurement result displaying the height of the detected particle. The highlighted area R in Figure 5 displays the position and height of the detected particle.

[0047] Now, an inspection method using the inspection system 10 will be described.

[0048] The medical container to be tested according to the present invention can be emptied of any fluids (liquids and / or gases) before testing begins, or testing can be performed while the medical container is filled with the medical product.

[0049] The white light confocal system 20 can be preconfigured to direct and focus the light beam LB emitted by the sensor head 22 onto a portion of the medical container that requires inspection. For example, the white light confocal system 20 can be configured to direct and focus the light beam LB onto an interior surface of the medical container, such as the interior surface 110 of the syringe 100 shown in FIG. 2. The interior surface of the medical container requires inspection because it defines an interior cavity and is the portion that typically requires the presence of particles to be avoided. For illustrative purposes, inspection of the interior surface 110 of the syringe 100 will be described below.

[0050] First, the detection of particles is performed by acquiring a 2D image of the entire inner surface 110 of the syringe 100 using the 2D sensor 26. The white light confocal system 20 is controlled to scan the inner surface 110 of the syringe 100 with the light beam LB emitted from the 2D sensor 26. The sensor head 22 is positioned relative to the syringe 100 in such a way that the white light is emitted from the 2D sensor 26 and is substantially orthogonal to the inner surface 110 of the syringe 100. To scan the entire circumference of the syringe 100, the scanning is performed as the syringe 100 is rotated by the rotary drive 50. The rotation speed is adjusted based on the processing speed of the white light confocal system 20. At this stage, if a particle is detected, only 2D information such as the length and width of the particle is acquired without measuring the height of the particle. Therefore, the processing speed is very fast.

[0051] While the scan processes the circumference of the syringe 100, the sensor head 22, or holder 12, is moved along the longitudinal direction, i.e., the X-axis, of the syringe 100 and continues scanning until the entire length of the barrel 102 has been scanned by the white light confocal system 20.

[0052] After the scan is completed, the 2D data processing unit 36 ​​generates a 2D image from the data acquired by the 2D sensor 26, as shown in FIG. 4, in which the particle P appears as a result of interference caused by signal detection by the 2D sensor 26.

[0053] The 2D data processing unit 36 ​​processes the 2D image to detect any particles that appear to be present on the image. As a result of the image processing, the dimensions (e.g., length and width) and positions of the particles P on the 2D image are identified. The 2D processing unit 36 ​​can also obtain the number of particles on the 2D image.

[0054] Therefore, by evaluating the 2D image generated from the data acquired by the 2D sensor 26 of the white light confocal system 20, it is possible to assess whether or not particles are present within or on the inner surface 110 of the syringe 100.

[0055] Next, height measurements of the particles detected by the previous step are performed. Knowing the position of each particle, the white light confocal system 20 scans only those areas of the inner surface 110 of the syringe 100 that contain particles detected by the previous detection process.

[0056] In this second stage, a 3D measurement is performed by the 3D sensor 28 and the 3D data processing unit 38. Thus, the complete profile, including the height of the detected particle, can be identified. Based on the results of the 3D measurement, a 3D graphic representing the geometric information of the particle's vicinity area can be generated, as shown, for example, in FIG.

[0057] Through the above inspection process, the following information is obtained: the number of particles found on the medical container, the location of each particle, and a 3D profile of each particle. The controller 30 generates a list of identified particles, categorized by size or other geometric information.

[0058] The inspection process according to the invention allows for rapid detection of particles of 10 μm or more, including their location. Subsequent 3D is performed only for the part where the particle is detected. As a result, the entire operation may be completed in a very short time, for example less than 5 minutes. Depending on the length and diameter of the syringe to be inspected, the time required can be further reduced. Also, the retrieval system allows for thorough inspection in a non-destructive manner. Since white light confocal systems are widely available on the market, it is easy to implement the invention.

[0059] The embodiments disclosed herein are presented for illustrative purposes only and are not intended to limit the scope of the invention, which is defined by the appended claims.

Claims

1. A method for inspecting a medical container (100) made of a light-transmitting material, comprising the steps of: scanning a portion (110) of a medical container (100) to be inspected with white light emitted from a white light confocal system (20); detecting light reflected from the portion (110) of the medical container (100) by the white light confocal system (20); determining whether particles are present in or on the portion (110) of the medical container (100) based on inspection results obtained by the white light confocal system (20); A method comprising:

2. The medical container (100) has a cylindrical shape, rotating the medical container (100) about a central axis of the medical container (100) during the scanning to perform inspection of the portion (110) of the medical container (100) at different locations along a circumference of the medical container (100); The method of claim 1 further comprising:

3. The medical container (100) has a longitudinal shape, moving the white light confocal system (20) relative to the medical container (100) during the scanning to perform inspection of the portion of the medical container (100) at different locations along a length of the medical container (100); The method of claim 1 or 2, further comprising:

4. the white light confocal system (20) comprises a 2D sensor (26), and the scanning and the detecting are performed by the 2D sensor (26); generating a 2D image of the portion (110) of the medical container (100) and indicating the presence or absence of the particle; Further equipped with The method according to any one of claims 1 to 3, wherein the determining is performed based on the 2D image.

5. If at least one particle is determined to be present, Counting the number of particles on the 2D image; The method of claim 4 further comprising:

6. If at least one particle is determined to be present, measuring the size and / or the position of each particle detected on the 2D image; The method of claim 4 or 5, further comprising:

7. The white light confocal system (20) further comprises a 3D sensor (28); If at least one particle is determined to be present, scanning the portion (110) of the medical container (100) containing the particle with white light emitted from the 3D sensor (28) of the white light confocal system (20); detecting light reflected by the portion (110) of the medical container (100) with the white light confocal system (20); obtaining 3D geometric information of the portion (110) of the medical container (100) containing the particle based on the detection results obtained by the white light confocal system (20); The method of any one of claims 4 to 6, further comprising:

8. generating a 3D image of the portion (110) of the medical container (100) including the geometric information of the particles; The method of claim 7 further comprising:

9. The method of any one of claims 1 to 8, wherein the scanning is performed with the light substantially orthogonal to the portion (110) of the medical container (100).

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