TWI849892B - Method and system for measuring the length of microneedles - Google Patents

Abstract

A method for measuring the length of microneedles which is suitable for measuring the length of a microneedle in a microneedle array structure through a system host, wherein the microneedle array structure is arranged in a first axial direction and has a plurality of microneedle. The method includes the following steps: projecting a laser scanning beam to a first end of the microneedle, and moving the laser scanning beam to a second end of the microneedle parts to obtain a first tomographic image data corresponding to the microneedle; and analyzing the first tomographic image data by a system host to obtain a first length value corresponding to the microneedle. Thereby, the method for measuring the length of microneedles of the present invention can be used to measure the structure of the microneedle array, and solve the problem that the internal structure of the microneedle cannot be inspected and the length of the microneedle cannot be measured. The system for measuring the length of microneedles is also provided.

Description

Method and system for measuring microneedle length

The present invention relates to a method and system for measuring microneedles, and in particular to a method and system for measuring the length of microneedles.

Since the length of microneedles ranges from tens of micrometers to several millimeters, and the diameter is around micrometers, they will not touch the pain receptors of the subcutaneous nervous system. They have the advantages of being painless, non-injurious to needles, and having a low rate of microbial invasion. Therefore, microneedles are widely used in the fields of biomedicine and medical cosmetology.

Generally speaking, after the microneedles are manufactured, the surface and shape of the microneedles are observed through the magnification function and rotation angle function of a digital microscope to check whether the external structure of the microneedles has defects.

One purpose of the present invention is to solve the problem that although the appearance defects of microneedles can be detected by using a digital microscope, the length of the microneedles cannot be measured.

Another purpose of the present invention is to solve the problem that although the appearance defects of microneedles can be detected by using a digital microscope, the internal structural problems of the microneedles cannot be detected.

Another purpose of the present invention is to solve the problem that after the microneedle is inserted into the skin, the length of the microneedle changes due to the material of the microneedle (for example, solubility), and the length change after the microneedle is inserted into the skin cannot be measured by observation using a digital microscope.

To achieve the above and other purposes, the present invention provides a method for measuring the length of microneedles, which is suitable for measuring the length of microneedles of a microneedle array structure, wherein the microneedle array structure is arranged in a first axial direction and has a plurality of microneedles. The method comprises the following steps: projecting a laser scanning beam to the first end of the microneedle, and moving the laser scanning beam to the second end of the microneedle to obtain first cross-sectional image data corresponding to the microneedle; and parsing the first cross-sectional image data by a system host to obtain a first length value corresponding to the microneedle.

In some embodiments, the method further comprises the following steps: rotating the microneedle array structure to be arranged in a second axial direction, the second axial direction being perpendicular to the first axial direction; projecting the laser scanning beam to the first end and the second end of the microneedle again to obtain second tomographic image data corresponding to the microneedle; analyzing the second tomographic image data by the system host to obtain a first optical path length value corresponding to the microneedle; and determining by the system host based on the first optical path length value. The refractive index is calculated by the ratio of the optical path length value to the first length value; the microneedle array structure is inserted into the skin, and a laser scanning beam is projected onto the microneedle array structure to obtain third-layer image data; the system host analyzes the third-layer image data to obtain a second optical path length value corresponding to the microneedle; and the system host calculates the second length corresponding to the microneedle according to the refractive index and the second optical path length value.

In some embodiments, the system host parses one of the first slice image data and the second slice image data to obtain the first image pixel value and pixel resolution, and calculates the first length value and the first optical path length value according to the first image pixel value and pixel resolution; the system host parses the third slice image data to obtain the second image pixel value, and calculates the second optical path length value according to the second image pixel value and pixel resolution.

In some embodiments, the laser scanning beam is generated by an optical coherent tomography scanner.

In some embodiments, a connecting cable is used to connect the optical coherence tomography scanner and the system host.

To achieve the above-mentioned and other purposes, the present invention provides a system for measuring the length of microneedles, which is suitable for measuring the length of microneedles of a microneedle array structure, wherein the microneedle array structure is arranged in a first axial direction and has a plurality of microneedles. The system comprises: an optical coherence tomography scanner for projecting a laser scanning beam to the first end of the microneedle and moving the laser scanning beam to the second end of the microneedle to obtain first tomographic image data corresponding to the microneedle; and a system host connected to the optical coherence tomography scanner for analyzing the first tomographic image data to obtain a first length value corresponding to the microneedle.

In some embodiments, the system host includes: a light source module connected to the optical coherence tomography scanner via a connecting cable to provide an optical scanning system light source to the optical coherence tomography scanner, so that the optical coherence tomography scanner generates a laser scanning beam; a spectrometer connected to the connecting cable to analyze the optical signal of the laser scanning beam scattered or reflected back to the connecting cable by the microneedle to obtain the first tomographic image data; and a processing module connected to the spectrometer to analyze the first tomographic image data to calculate and obtain the first length value.

In some embodiments, the microneedle array structure is arranged in a second axial direction, which is perpendicular to the first axial direction; the optical coherence tomography scanner projects the laser scanning beam to the first end and the second end of the microneedle again to obtain the second tomographic image data corresponding to the microneedle; the system host analyzes the second tomographic image data to obtain the first optical path length value corresponding to the microneedle, and calculates the refractive index according to the ratio of the first optical path length value to the first length value.

In some embodiments, the system host analyzes one of the first tomographic image data and the second tomographic image data to obtain the first image pixel value and pixel resolution, and calculates the first length value and the first optical path length value according to the first image pixel value and pixel resolution.

In some embodiments, after the microneedle array structure is inserted into the skin, the optical coherence tomography scanner projects a laser scanning beam to the microneedle array structure to obtain third-layer image data; the system host analyzes the third-layer image data to obtain the second optical path length value corresponding to the microneedle, and calculates the second length value corresponding to the microneedle based on the refractive index and the second optical path length value.

In some embodiments, the system host parses the third tomographic image data to obtain the second image pixel value, and calculates the second optical path length value based on the second image pixel value and the pixel resolution.

Thus, the method and system for measuring the length of microneedles of the present invention utilizes an optical coherence tomography (OCT) instrument to obtain cross-sectional image data, and obtains the first length value and refractive index of the microneedle through an image analysis program and a formula calculation program, thereby solving the problem that the conventional technology cannot measure the length of the microneedle, and the embodiment of the present invention uses a non-invasive method to measure the length of the microneedle, thereby minimizing the impact of the measurement process on the structure of the microneedle. In addition, the cross-sectional image data obtained by the present invention using the OCT instrument can be used to check and confirm whether the internal structure of the microneedle is defective, thereby solving the problem that the conventional technology cannot check the internal structure of the microneedle, thereby improving the quality control of the microneedle. In addition, by analyzing the cross-sectional image data after the microneedle is inserted into the skin and using a formula calculation program, the length of the microneedle after it is inserted into the skin is calculated, solving the problem that conventional technology cannot measure the length of the microneedle after it is inserted into the skin.

10: Microneedle array structure

100: System for measuring microneedle length

12, 14: Microneedle

121: Needle tip

122: Needle end

12a: Pixel unit

20: Optical coherence tomography scanner

22: Laser scanning beam

200: First slice image data

30: System host

32: Light source module

34: Spectrometer

36: Processing module

300: Second slice image data

310: Third-layer image data

40: Connecting cables

50: Skin

60: Steering mechanism

L1: first length value

L2: Second length value

X, Y, Z: axial direction

S600, S602, S604: Steps

S606, S608, S610, S612, S614, S616, S618: Steps

[Figure 1] is a schematic diagram of a system for measuring the length of microneedles according to an embodiment of the present invention.

[Figure 2] is a schematic diagram of the analysis of the first slice image data according to the embodiment of the present invention.

[Figure 3] is another schematic diagram of the measurement microneedle array structure according to an embodiment of the present invention.

[Figure 4] is a schematic top view of the microneedle array structure according to the embodiment of Figure 3 of the present invention.

[Figure 5] is a schematic diagram of the analysis of the second tomographic image data according to an embodiment of the present invention.

[Figure 6] is a schematic diagram of the analysis of the third slice image data according to the embodiment of the present invention.

[Figure 7] is a flow chart of a method for measuring the length of microneedles according to an embodiment of the present invention.

[Figure 8A] and [Figure 8B] are flow charts of a method for measuring the length of microneedles according to another embodiment of the present invention.

In order to fully understand the purpose, features and effects of the present invention, the present invention is described in detail by means of the following specific embodiments and the attached drawings. The description is as follows: Please refer to FIG. 1, which is a schematic diagram of a system for measuring the length and refractive index of microneedles according to an embodiment of the present invention. The system 100 for measuring the length of microneedles includes: a microneedle array structure 10, an optical coherence tomography scanner 20, a system host 30 and a connecting cable 40.

The microneedle array structure 10 is arranged in a first axial direction. The first axial direction refers to the needle tip 121 of the microneedle 12 facing the X-axis direction, but it is not limited to this. In other embodiments, the first axial direction may also refer to the needle tip 121 of the microneedle 12 facing the Y-axis direction. The microneedle array structure 10 can be fixed and arranged on the turning mechanism 60. In other embodiments, the microneedle array structure 10 can also be fixed and arranged on a mechanical moving/rotating mechanism (not shown, for example, a lifting platform or a robotic arm) to achieve the purpose of being arranged in the first axial direction. The microneedle array structure 10 has a plurality of microneedles 12. The microneedles 12 are arranged in a staggered manner, but it is not limited to this. In other embodiments, the microneedles 12 are arranged in a non-staggered manner.

The turning mechanism 60 is connected to the microneedle array structure 10. The turning mechanism 60 is used to control the rotation direction of the microneedle array structure 10. The turning mechanism 60 can be, for example, a lifting platform or a robotic arm. In this embodiment, the turning mechanism 60 is used to realize the fixation and rotation direction control of the microneedle array structure 10, but it is not limited to this.

The optical coherence tomography scanner 20 is disposed above the microneedle array structure 10. The optical coherence tomography scanner 20 is used to generate and project a laser scanning beam 22 to the microneedles 12, and the optical coherence tomography scanner 20 is connected to the system host 30 via a connecting cable 40. The optical coherence tomography scanner 20 generates the laser scanning beam 22 according to the optical scanning system light source (not shown), and projects the laser scanning beam 22 to the microneedles 12 on the microneedle array structure 10. The projection direction (e.g., Z axis) of the laser scanning beam 22 is perpendicular to the first axis (e.g., X axis). In other embodiments, the projection direction of the laser scanning beam 22 is substantially perpendicular to the first axis. The laser scanning beam 22 is, for example, a near-infrared beam. In addition, the optical coherence tomography scanner 20 can be fixed and disposed on another mechanical moving/rotating/turning mechanism (not shown, for example, a lifting platform or a robotic arm) to achieve the movement of the projected laser scanning beam 22 from the first end (for example, the needle end 122) to the second end (for example, the needle tip 121) of the microneedle 12. In other embodiments, the projected laser scanning beam 22 can move from the needle tip 121 of the microneedle 12 to the needle end 122. In other embodiments, the projected laser scanning beam 22 can move back and forth between the needle tip 121 and the needle end 122 of the microneedle 12. In other embodiments, the optical coherence tomography scanner 20 may also be, for example, a handheld optical coherence tomography scanner.

The system host 30 is connected to the optical coherence tomography scanner 20 via a connecting cable 40. The system host 30 includes a light source module 32, a spectrometer 34, and a processing module 36. In addition, the system host 30 is also provided with an instrumentation circuit (not shown) or other necessary components with computer control, calculation and/or storage functions.

The light source module 32 is connected to the connecting cable 40. The light source module 32 is used to provide the optical scanning system light source to the optical coherence tomography scanner 20, so that the optical coherence tomography scanner 20 generates a laser scanning beam 22.

The spectrometer 34 is connected to the connecting cable 40. The spectrometer 34 is used to receive the optical signal scattered or reflected by the microneedle 12 through the connecting cable 40, so as to analyze the optical signal, so as to obtain the first tomographic image data 200 (see FIG. 2 ), the second tomographic image data 300 (see FIG. 5 ) or the third tomographic image data 310 (see FIG. 6 ). The first tomographic image data 200 corresponds to the image data obtained by scanning when the microneedle 12 is set in the first axial direction. The second tomographic image data 300 corresponds to the image data obtained by scanning when the microneedle 12 is set in the second axial direction. The third cross-sectional image data 310 corresponds to the image data obtained by scanning after the microneedle 12 is inserted into the skin.

The processing module 36 is connected to the spectrometer 34. The processing module 36 is used to analyze the first cross-sectional image data 200, the second cross-sectional image data 300 or the third cross-sectional image data 310 to calculate and obtain the first length value L1 (see Figure 2, Figure 5), the second length value L2 (see Figure 6), the first optical path length value, the second optical path length value or the refractive index corresponding to the microneedle 12. The processing module 36 may include a general-purpose processor, a dedicated processor, a central processing unit, a digital signal processor, a microprocessor, a memory, a memory controller and/or a hard disk, etc.

Specifically, the processing module 36 analyzes one of the first slice image data 200 and the second slice image data 300 to obtain the first image pixel value and pixel resolution, and can calculate the first length value L1 or refractive index according to the following formula (1): first length value L1×refractive index=first image pixel value×pixel resolution......(1)

The first image pixel value refers to the number of pixel units 12a (as shown in FIG. 2 ) between the needle tip 121 and the needle end 122. The pixel resolution refers to the length represented by one pixel unit 12a. The first image pixel value × pixel resolution = first length value. The aforementioned pixel resolution is, for example, based on the calculation of the X-axis direction of FIG. 2 . In addition, the calculation method of the pixel resolution can be obtained by measuring the standard film.

Based on the above formula (1), it can be known that the calculation method of the first length value L1 is pixel resolution × first image pixel value ÷ refractive index. The processing module 36 can perform operations according to the above calculation formula (1) and obtain the first length value L1 or refractive index corresponding to the microneedle 12. Since the first length value L1 in the embodiment of the present invention is obtained by analyzing the first tomographic image data 200, because the laser scanning beam 22 is mainly projected on one side surface of the microneedle 12 (for example, the upper surface), and the first length value L1 is on the same horizontal plane, the influence of the refractive index is very small, so the refractive index can be ignored. Therefore, formula (1) can be corrected to the following formula (2): first length value L1 = pixel resolution × first image pixel value......(2)

The connecting cable 40 is connected to the optical coherence tomography scanner 20 and the system host 30 respectively. The connecting cable 40 includes an optical fiber (not shown in the figure) and an electric wire (not shown in the figure). The connecting cable 40 is used to transmit optical signals and/or electric signals.

Please refer to FIG. 2, which is a schematic diagram of the analysis of the first tomographic image data according to an embodiment of the present invention. The first tomographic image data 200 contains an image of the microneedle array structure 10. Taking a single microneedle 12 as an example, the processing module 36 performs an analysis procedure based on the first tomographic image data 200. The analysis procedure can, for example, be to use image recognition software to identify the image data containing the microneedle 12 according to the image feature value to analyze the needle tip 121 and the needle end 122 of the microneedle 12. Then, the processing module 36 calculates the number of pixel units 12a between the needle tip 121 and the needle end 122 to calculate the first image pixel value. Finally, the processing module 36 can calculate the first length value L1 according to formula (2). In this way, the problem that the conventional technology cannot measure the length of the microneedle is solved, and the embodiment of the present invention adopts a non-invasive method to measure the length of the microneedle, which minimizes the impact of the measurement process on the structure of the microneedle. In addition, the cross-sectional image of the first tomographic image data 200 can be used to check and confirm whether the internal structure of the microneedle is defective, solving the problem that the conventional technology cannot check the internal structure of the microneedle.

Please refer to Figure 3, which is another schematic diagram of the measurement microneedle array structure according to an embodiment of the present invention. The microneedle array structure 10 is arranged in a second axial direction. The second axial direction is perpendicular to the first axial direction. The second axial direction refers to the needle tip 121 of the microneedle 12 facing the Z-axis direction. Similarly, the microneedle array structure 10 can be fixed and set on a mechanical moving/rotating/turning mechanism (for example, a lifting platform or a robotic arm) to achieve the purpose of being set in the second axial direction. The optical coherence tomography scanner 20 is used to generate and project a laser scanning beam 22 to the microneedle 12. More specifically, the projected laser scanning beam 22 is transmitted from the needle tip 121 of the microneedle 12 to the needle end 122, and then returns to the spectrometer 34 of the system host 30 via the path of the needle end 122, the needle tip 121, the optical coherence tomography scanner 20, and the connecting cable 40, so that the spectrometer 34 obtains the second tomographic image data 300. The projection direction (e.g., Z axis) of the laser scanning beam 22 is parallel to the second axis (e.g., Z axis). In other embodiments, the projection direction of the laser scanning beam 22 is substantially parallel to the second axis. In other embodiments, when other microneedles on the microneedle array structure 10 are to be measured, the optical coherence tomography scanner 20 can be controlled to move from above the microneedle 12 to above the microneedle 14 along the measurement direction to obtain the second tomographic image data 300 corresponding to each microneedle between microneedle 12 and microneedle 14.

Please refer to FIG. 4, which is a top view schematic diagram of the microneedle array structure according to the embodiment of FIG. 3 of the present invention. It can be seen more clearly that the microneedles are arranged in a staggered manner. The optical coherence tomography scanner 20 moves from the top of the microneedle 12 to the top of the microneedle 14 along the measurement direction to obtain the second tomographic image data 300 corresponding to each microneedle between microneedle 12 and microneedle 14. In other embodiments, the measurement direction can also be from the top of the microneedle 14 to the top of the microneedle 12. In other embodiments, multiple rows of microneedles can also be measured at one time to save measurement time.

Please refer to FIG. 5 , which is a schematic diagram of the analysis of the second tomographic image data according to an embodiment of the present invention. The second tomographic image data 300 includes an image of the microneedle array structure 10. Taking a single microneedle 12 as an example, the processing module 36 performs an analysis procedure based on the second tomographic image data 300. The analysis procedure can be, for example, through image recognition software, to identify the image data containing the microneedle 12 according to the image feature value to analyze the needle tip 121 and the needle end 122 of the microneedle 12. Then, the processing module 36 calculates how many pixel units 12a there are from the needle tip 121 to the needle end 122 to calculate the first image pixel value, and then after multiplying the pixel resolution by the first image pixel value, the first optical path length value can be obtained. Since the projected laser scanning beam 22 enters from the needle tip 121 to the needle end 122 and then returns from the needle end 122 to the needle tip 121, the obtained second tomographic image data 300 is affected by the refractive index, so the refractive index can be calculated according to formula (1). For example, the processing module 36 inputs the pixel resolution (for example, based on the Z axis direction), the first image pixel value and the first length value L1 into formula (1) to calculate the refractive index.

Please refer to FIG. 6 , which is a schematic diagram of the analysis of the third tomographic image data according to an embodiment of the present invention. The third tomographic image data 310 contains an image of the microneedle array structure 10, and the microneedle array structure 10 is inserted into the skin 50. Due to the material (e.g., solubility) of the microneedle 12, the length of the microneedle 12 changes. Through this embodiment, the second length value L2 after the length of the microneedle 12 changes can be measured. Taking a single microneedle 12 as an example, the processing module 36 performs an analysis procedure based on the third tomographic image data 310. The analysis procedure can, for example, be to identify the image data containing the microneedle 12 based on the image feature value through image recognition software to analyze the needle tip 121 and the needle end 122 of the microneedle 12. Next, the processing module 36 analyzes the third slice image data 310 to obtain the second image pixel value. Specifically, the processing module 36 calculates the number of pixel units 12a between the needle tip 121 and the needle end 122 to calculate the second image pixel value, and then multiplies the pixel resolution by the second image pixel value to obtain the second optical path length value. Since the projected laser scanning beam 22 enters from the needle tip 121 to the needle end 122 and then returns from the needle end 122 to the needle tip 121, the obtained third slice image data 310 is affected by the refractive index. The refractive index has been calculated and obtained in the embodiment of FIG5 , so the second length value L2 can also be obtained by using the calculation method of formula (1), except that the first length value L1 in formula (1) is replaced by the second length value L2 and the first image pixel value is replaced by the second image pixel value. In this embodiment, the second image pixel value is less than the first image pixel value. Then, after the refractive index is substituted into formula (1), the second length value L2 can be calculated. For example, after the processing module 36 inputs the pixel resolution, the second image pixel value and the refractive index into formula (1), the second length value L2 can be calculated. In addition, the pixel resolution can be calculated by placing the reflector on another mechanical moving/rotating/turning mechanism, measuring the reflector once in the original position, and then raising the reflector a predetermined distance (for example, 500μm) and measuring it again. The pixel difference obtained by subtracting the two measured object interface heights is a distance of 500μm in the air, and 500μm divided by the pixel difference is the pixel resolution.

The following example illustrates how the present invention can be used to observe the condition of the microneedle array structure 10 after it is inserted into the skin 50 in a non-invasive manner (e.g., whether it penetrates the stratum corneum or epidermis).

595μm。藉此，可以得知，微針12的長度由616μm縮短至595μm。 First, before the microneedle array structure 10 is inserted into the skin, the first length value L1 of the microneedle 12 is 616 μm, the first optical path length value is 801 μm, and the refractive index is 1.3. Then, the microneedle array structure 10 is inserted into the skin 50, and the optical coherence tomography scanner 20 is used to scan and obtain the third tomographic image data 310 after the microneedle 12 is inserted into the skin 50. The processing module 36 can analyze the third tomographic image data 310 to find that the microneedle 12 has 129 pixel units 12a and multiply 129 by the pixel resolution (for example, 6 μm) to obtain the second optical path length value. The processing module 36 then divides the second optical path length value by the refractive index (for example, 1.3) to obtain the second length value L2 of the microneedle 12. Therefore, the second length value L2 is: 129×6÷1.3

Thus, it can be known that the length of the microneedle 12 is shortened from 616 μm to 595 μm.

In addition, the third tomographic image data 310 can be analyzed to show that the length of the microneedle 12 exposed to the air has 56 pixel units 12a. The processing module 36 multiplies 56 by the pixel resolution (e.g., 6μm) to obtain the length of the microneedle 12 exposed to the air: 56×6=336μm. The processing module 36 subtracts the length of the microneedle 12 exposed to the air from the second length value L2 to obtain the length of the microneedle after being inserted into the skin 50: 595-336=259μm. In this way, the state of the microneedle array structure 10 after being inserted into the skin 50 is observed in a non-invasive manner to confirm whether the microneedle array structure 10 penetrates the stratum corneum or the epidermis, and solves the problem that the conventional technology cannot measure the length of the microneedle after being inserted into the skin.

Please refer to FIG. 7, which is a flow chart of a method for measuring the length of a microneedle according to an embodiment of the present invention. Step S600, the microneedle array structure 10 is arranged in a first axial direction, and the microneedle array structure 10 has a plurality of microneedles 12.

Step S602, projecting a laser scanning beam 22 to the first end of the microneedle 12 (e.g., the needle end 122), and moving the laser scanning beam 22 to the second end of the microneedle (e.g., the needle tip 121) to obtain the first cross-sectional image data 200 corresponding to the microneedle. The projection direction of the laser scanning beam 22 is perpendicular to the first axis.

In step S604, the system host 30 analyzes the first cross-sectional image data 200 to obtain the first length value L1 corresponding to the microneedle. The first length value L1 is calculated according to formula (2).

Please refer to Figures 8A and 8B, which are flow charts of a method for measuring the length of microneedles in another embodiment of the present invention. Steps S600, S602, and S604 in Figure 8A are the same as those in the embodiment of Figure 7 and are not described in detail here. Step S606: Rotate the microneedle array structure 10 to set it in a second axial direction. The second axial direction is perpendicular to the first axial direction.

In step S608, the laser scanning beam 22 is projected again to the first end and the second end of the microneedle 12 to obtain the second cross-sectional image data 300 corresponding to the microneedle 12. The projection direction of the laser scanning beam 22 is parallel to the second axial direction. Since the second cross-sectional image data 300 can simultaneously present the image features of the external and internal structures of the microneedle, it can be used to check and confirm whether the internal structure of the microneedle has defects. In this way, the problem that the conventional technology can only observe the external structure of the microneedle but cannot check the internal structure of the microneedle is solved. In addition, in other embodiments, steps S606, S608 and 608 can be executed first, and then steps S600, S602 and S604 can be executed. In other words, there is no order in the steps of obtaining the first slice image data 200 and the second slice image data 300.

In step S610, the system host 30 analyzes the second cross-sectional image data 300 to obtain the first optical path length value corresponding to the microneedle 12. The first optical path length value is calculated based on the pixel resolution × the first image pixel value.

In step S612, the system host 30 calculates the refractive index based on the ratio of the first optical path length value to the first length value L1. The system host 30 can calculate the refractive index based on formula (1).

Step S614, insert the microneedle array structure 10 into the skin 50, and project the laser scanning beam 22 onto the microneedle array structure 10 to obtain the third tomographic image data 310.

In step S616, the system host 30 analyzes the third tomographic image data 310 to obtain the second optical path length value corresponding to the microneedle 12. The second optical path length value is calculated based on the pixel resolution × the second image pixel value.

In step S618, the system host 30 calculates the second length value L2 corresponding to the microneedle 12 according to the refractive index and the second optical path length value. The second length value L2 is calculated according to the second optical path length value ÷ the refractive index.

In summary, the method and system for measuring the length of microneedles of the present invention utilizes an OCT instrument (e.g., including an optical coherence tomography scanner 20 and a spectrometer 34) to obtain cross-sectional image data, and obtains the first length value L1 and the refractive index of the microneedle through an image analysis program and a formula calculation program, thereby solving the problem that the conventional technology cannot measure the length of the microneedle, and the embodiment of the present invention uses a non-invasive method to measure the length of the microneedle, thereby minimizing the impact of the measurement process on the structure of the microneedle. In addition, the cross-sectional image data obtained by the present invention using the OCT instrument can be used to check and confirm whether the internal structure of the microneedle is defective, thereby solving the problem that the conventional technology cannot check the internal structure of the microneedle, thereby improving the quality control of the microneedle. In addition, by analyzing the cross-sectional image data after the microneedle is inserted into the skin and using a formula calculation program, the length of the microneedle after it is inserted into the skin is calculated, solving the problem that conventional technology cannot measure the length of the microneedle after it is inserted into the skin.

The present invention has been disclosed in the above text with a preferred embodiment, but those familiar with the present technology should understand that the embodiment is only used to describe the present invention and should not be interpreted as limiting the scope of the present invention. It should be noted that all changes and substitutions equivalent to the embodiment should be included in the scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the patent application.

S600, S602, S604: Steps

Claims (8)

A method for measuring the length of a microneedle is applicable to measuring the length of a microneedle of a microneedle array structure, wherein the microneedle array structure is arranged in a first axial direction and has a plurality of microneedles. The method comprises the following steps: projecting a laser scanning beam to a first end of the microneedle, and moving the laser scanning beam to a second end of the microneedle to obtain a first tomographic image data corresponding to the microneedle; parsing the first tomographic image data by a system host to obtain a first length value corresponding to the microneedle; rotating the microneedle array structure to be arranged in a second axial direction, the second axial direction being perpendicular to the first axial direction; projecting the laser scanning beam again to the first end of the microneedle and the second end of the microneedle; and The second end is connected to the microneedle array structure to obtain a second cross-sectional image data corresponding to the microneedle; the system host analyzes the second cross-sectional image data to obtain a first optical path length value corresponding to the microneedle; the system host calculates a refractive index according to the ratio of the first optical path length value to the first length value; the microneedle array structure is inserted into a skin, and the laser scanning beam is projected to the microneedle array structure to obtain a third cross-sectional image data; the system host analyzes the third cross-sectional image data to obtain a second optical path length value corresponding to the microneedle; and the system host calculates a second length value corresponding to the microneedle according to the refractive index and the second optical path length value. A method for measuring the length of a microneedle as described in claim 1, wherein the system host parses one of the first cross-sectional image data and the second cross-sectional image data to obtain a first image pixel value and a pixel resolution, and calculates the first length value and the first optical path length value based on the first image pixel value and the pixel resolution; the system host parses the third cross-sectional image data to obtain a second image pixel value, and calculates the second optical path length value based on the second image pixel value and the pixel resolution. The method for measuring the length of a microneedle as described in claim 1 further includes generating the laser scanning beam using an optical coherent tomography scanner. The method for measuring the length of a microneedle as described in claim 3 further includes connecting the optical coherence tomography scanner and the system host with a connecting cable. A system for measuring the length of microneedles is suitable for measuring the length of microneedles of a microneedle array structure, wherein the microneedle array structure is arranged in a first axial direction and has a plurality of microneedles. The system comprises: an optical coherence tomography scanner for projecting a laser scanning beam to a first end of the microneedles and moving the laser scanning beam to a second end of the microneedles to obtain a first cross-sectional view corresponding to the microneedles. a system host connected to the optical coherence tomography scanner to analyze the first tomography image data to obtain a first length value corresponding to the microneedle; a light source module connected to the optical coherence tomography scanner via a connecting cable to provide an optical scanning system light source to the optical coherence tomography scanner so that the optical coherence tomography scanner generates the laser scanning light. beam; a spectrometer connected to the connecting cable, used to analyze the optical signal of the laser scanning beam scattered or reflected by the microneedle back to the connecting cable to obtain the first tomographic image data; and a processing module connected to the spectrometer, used to analyze the first tomographic image data to calculate and obtain the first length value; wherein the microneedle array structure is arranged in a second axial direction, the second axis The optical coherence tomography scanner projects the laser scanning beam to the first end and the second end of the microneedle again to obtain a second tomographic image data corresponding to the microneedle; the system host analyzes the second tomographic image data to obtain a first optical path length value corresponding to the microneedle, and calculates a refractive index according to the ratio of the first optical path length value to the first length value. A system for measuring the length of a microneedle as described in claim 5, wherein the system host analyzes one of the first cross-sectional image data and the second cross-sectional image data to obtain a first image pixel value and a pixel resolution, and calculates the first length value and the first optical path length value based on the first image pixel value and the pixel resolution. A system for measuring the length of microneedles as described in claim 6, wherein after the microneedle array structure is inserted into a skin, the optical coherence tomography scanner projects the laser scanning beam to the microneedle array structure to obtain a third tomographic image data; the system host analyzes the third tomographic image data to obtain a second optical path length value corresponding to the microneedle, and calculates a second length value corresponding to the microneedle based on the refractive index and the second optical path length value. A system for measuring the length of a microneedle as described in claim 7, wherein the system host analyzes the third tomographic image data to obtain a second image pixel value, and calculates a second optical path length value based on the second image pixel value and the pixel resolution.

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