阅读说明：本技术 用于检查安放在注射器上的针头的状态的方法和装置 (Method and device for checking the condition of a needle mounted on a syringe ) 是由 M·卡尔 C·斯蒂尔尼曼 于 2019-08-06 设计创作，主要内容包括：本发明涉及一种用于检查安放在注射器(1)上的针头(2)(或注射针)的状态、尤其是用于识别所述针头的故障的方法和用于实施这种方法的装置,该针头位于保护帽(3)的下面。根据本发明的方法包括测量在针头(2)周围的磁场(尤其磁场分布)。铁磁针头(2)的存在引起磁场线走向的局部改变。这可以被测量和用于确定针头(2)是否如希望的那样笔直地且与注射器纵轴线a同轴地布置,或者是否该针头具有故障,例如弯曲、弯折、压缩、断裂/折断、相对于注射器纵轴线a倾斜或者相对于注射器纵轴线a偏心。(The invention relates to a method for checking the state of a needle (2) (or injection needle) placed on a syringe (1), which is located below a protective cap (3), in particular for identifying a malfunction of the needle, and to a device for carrying out the method. The method according to the invention comprises measuring the magnetic field (in particular the magnetic field distribution) around the needle (2). The presence of the ferromagnetic needle (2) causes a local change in the course of the magnetic field lines. This can be measured and used to determine whether the needle (2) is arranged straight and coaxially with the syringe longitudinal axis a as desired, or whether the needle has a malfunction, such as bending, kinking, compressing, breaking/snapping, tilting relative to the syringe longitudinal axis a or being eccentric relative to the syringe longitudinal axis a.)

1. Method for checking the condition of a needle (2) placed on a syringe (1) in a needle protecting cap (3), wherein the method comprises measuring a magnetic field, in particular a magnetic field distribution, around the needle (2).

2. Method according to claim 1, wherein for measuring the magnetic field, in particular the magnetic field distribution, one or more magnetic field sensors (4) are used_1…5、4_A) In particular inductive sensors, fluxgate magnetometers, Hall sensors, magnetoresistive sensors, for example AMR-, CMR-, GMR-or TMR-sensors.

3. Method according to claim 2, wherein the one or more magnetic field sensors (4) are connected to_1…5、4_A) Magnetic field sensor (4) embodied as a single, double or triple axis_1…5、4_A) In order to determine the magnetic field, in particular the magnetic field distribution, in one, two or three dimensions.

4. Method according to claim 2 or 3, wherein for measuring the magnetic field, in particular the magnetic field distribution, the needle (2) is brought relative to the one or more magnetic field sensors (4)_1…5、4_A) Wherein the injector (1) is rotated in particular about its longitudinal axis (a) and/or moved along its longitudinal axis (a), or the one or more magnetic field sensors (4) are moved_1…5、4_A) Parallel to the longitudinal axis (a) of the syringe (1).

5. Method according to any of claims 1-4, wherein the magnetic field is at least partly generated by the earth's magnetic field, by the magnetic field formed by an assembly with one or more permanent magnets, or by an assembly with one or more electromagnets, such as Helmholtz coils (7)₁、7₂) The assembly of (2) generates a magnetic field, wherein the assembly also has, in particular, one or more cores.

6. The method according to any one of claims 1 to 5, wherein a magnetic shield is used for suppressing disturbing magnetic fields.

7. The method of any of claims 1 to 6, the method comprising: comparing the magnetic field, in particular the measured magnetic field distribution, measured for the needle (2) with the magnetic field, in particular the measured magnetic field distribution, measured for a reference syringe with a reference needle seated in a needle protection cap having a target state; and determining the state of the needle (2) mounted on the syringe (1) based on the comparison.

8. The method according to claim 7, wherein the determination of the state of the needle (2) mounted on the syringe (1) is based on a comparison of the amplitude and/or phase of the magnetic field measured for the reference needle with the amplitude and/or phase of the magnetic field measured for the needle (2).

9. The method according to any of claims 1 to 8, comprising converting the magnetic field, in particular the time-varying curve of the magnetic field distribution, from the time domain to the frequency domain.

10. The method according to any one of claims 1 to 9, wherein the state of the needle (2) is at least one of straight, bent, compressed, broken/fractured, coaxial with the syringe longitudinal axis (a), inclined with respect to the syringe longitudinal axis (a), eccentric with respect to the syringe longitudinal axis (a).

11. Device for checking the condition of a needle (2) placed on a syringe (1) in a needle-protecting cap (3), said needle being located in the needle-protecting cap (3), wherein the device comprises one or more magnetic field sensors (4)_1…5、4_A) In particular an inductive sensor, a fluxgate magnetometer, a hall sensor, a magnetoresistive sensor, such as an AMR-, CMR-, GMR-or TMR-sensor, for measuring a magnetic field, in particular a magnetic field distribution, around the needle (2).

12. The device according to claim 11, wherein the one or more magnetic field sensors (4)_1…5、4_A) Magnetic field sensor (4) embodied as a single, double or triple axis_1…5、4_A) In order to determine the magnetic field, in particular the magnetic field distribution, in one, two or three dimensions.

13. The device according to claim 11 or 12, further comprising means for bringing the needle (2) relative to the one or more magnetic field sensors (4)_1…5、4_A) A movement, in particular a rotation of the syringe (1) about its longitudinal axis (a) and/or a movement of the syringe (1) along its longitudinal axis (a), or a movement of the one or more magnetic field sensors (4)_1…5、4_A) A device (6) moving parallel to the longitudinal axis (a) of the syringe (1).

14. Device according to any of claims 11 to 13, further comprising an assembly with one or more permanent magnets, and/or with one or more electromagnets, such as helmholtz coils (7)₁、7₂) For generating a magnetic field, wherein the assembly also has, in particular, one or more cores.

15. The apparatus of any one of claims 11 to 14, further comprising a magnetic shield for suppressing interfering magnetic fields.

16. Device according to any one of claims 11 to 15, further comprising a comparison unit for comparing a magnetic field, in particular a measured magnetic field distribution, measured for the needle (2) with a magnetic field, in particular a measured magnetic field distribution, measured for a reference syringe with a reference needle seated in a needle-protecting cap having a target state; and determining the state of the needle (2) mounted on the syringe (1) based on the comparison.

17. The device according to claim 16, wherein the comparison unit is configured for carrying out a comparison of the amplitude and/or phase of the magnetic field measured for the reference needle with the amplitude and/or phase of the magnetic field measured for the needle and determining therefrom the state of the needle (2) mounted on the syringe (1).

18. The apparatus according to any of claims 11 to 17, further comprising means for converting the measured time profile of the magnetic field, in particular the magnetic field distribution, from the time domain to the frequency domain.

19. The device according to any one of claims 11 to 18, further comprising an output, in particular for providing an output signal, configured for indicating the state of the needle (2) as at least one of straight, bent, compressed, broken/snapped, coaxial with the syringe longitudinal axis (a), inclined with respect to the syringe longitudinal axis (a), eccentric with respect to the syringe longitudinal axis (a).

Technical Field

The invention relates to a method for checking the condition of a needle (or injection needle) mounted on a syringe, in particular for detecting a malfunction of the needle, and to a device for carrying out the method.

Background

In the production of medical syringes, when placing an opaque protective cap (english "Needle Shield"), it can happen that the Needle or Needle located thereunder is bent or compressed, which penetrates the protective cap or even breaks. The needle thus not only becomes dangerous for the user, but also loses its sterility. Various methods are used today to identify such damage. Thus, for example, conventional image processing is applied in order to detect the position of the protective cap. However, this method eliminates a relatively high proportion of good quality syringes (high "false rejection rate"). The most reliable method possible today is based on X-ray examination of each syringe and automatic analysis of the X-ray examination images taken. However, this technique is rather complicated and therefore, for example, the X-ray examination area must be shielded from the outside, which is very costly. In addition, the product is burdened with X-ray inspection radiation. Alternatively there is a high voltage test. In this case, the electrode under high voltage is held at the end with a protective cap. If the needle pierces the protective cap, this can be identified by means of a high-pressure test. But a bent, compressed or broken needle under the intact protective cap cannot be reliably identified.

There is therefore a need for a means of achieving a simple (and therefore cost-effective) and reliable identification of the malfunction of a needle mounted on a syringe. In order to be able to be used in inspection machines with high throughput of samples to be tested (for example about 600 syringes per minute), these measures must also be able to test individual samples to be tested very quickly and with high reliability.

Disclosure of Invention

The object of the present invention is to provide a method for quickly, reliably and cost-effectively checking the state of a needle mounted on a syringe, in particular for identifying a malfunction of the needle. According to the invention, this object is achieved by a test method as defined in claim 1.

The object of the invention is, furthermore, to provide a corresponding device for quickly, reliably and cost-effectively checking the condition of a needle mounted on a syringe, in particular for detecting a malfunction of the needle. According to the invention, this object is achieved by a test device as defined in claim 11.

Particular embodiments of the invention are specified in the dependent claims.

The method according to the invention for checking the condition of a needle placed on a syringe in a needle protecting cap, in particular for identifying certain faults of said needle, comprises measuring the magnetic field (in particular the magnetic field distribution) around the needle.

In one embodiment variant of the method, one or more magnetic field sensors, in particular inductive sensors, fluxgate magnetometers, hall sensors, magnetoresistive sensors, for example AMR- (english "anisotropic magnetoresistive"), CMR- (english "ferromagnetic"), GMR- (english "or TMR- (english" magnetoresistive ") sensors, are used for measuring the magnetic field (in particular the magnetic field distribution).

In a further embodiment variant of the method, the magnetic field sensor or sensors are embodied as single-axis, two-axis or three-axis magnetic field sensors in order to determine the magnetic field (in particular the magnetic field distribution) in one, two or three dimensions.

In a further embodiment variant of the method, the needle is moved relative to one or more magnetic field sensors for measuring the magnetic field (in particular the magnetic field distribution), wherein the syringe is in particular rotated about its longitudinal axis and/or moved along its longitudinal axis, or the one or more magnetic field sensors are moved parallel to the longitudinal axis of the syringe.

In a further embodiment variant of the method, one or more motors, for example servo motors or stepper motors, are used for rotating and/or longitudinally moving the injector, wherein a transmission is used, so that the rotational frequency of the one or more motors is a multiple or a fraction of the rotational frequency of the injector. Thereby preventing interference with the magnetic field generated by the motor or motors, the magnetic field to be measured around the needle or the magnetic field distribution to be measured.

In a further embodiment variant of the method, the magnetic field is generated at least in part by the earth magnetic field, by the magnetic field formed by an assembly of one or more permanent magnets or by the magnetic field formed by an assembly of one or more electromagnets, such as helmholtz coils, wherein the assembly in particular also has one or more iron cores.

In a further embodiment variant of the method, a magnetic shield is used for suppressing the disturbing magnetic field.

In another embodiment variant, the method comprises: comparing the magnetic field measured (in particular the measured magnetic field distribution) for the needle with the magnetic field measured (in particular the measured magnetic field distribution) for a reference syringe with a reference needle seated in a needle protecting cap having a target state; and determining the status of the needle mounted on the syringe based on this comparison.

In a further embodiment variant of the method, the determination of the state of the needle mounted on the syringe is based on a comparison of the amplitude and/or phase of the magnetic field measured for the reference needle with the amplitude and/or phase of the magnetic field measured for the needle.

In a further embodiment variant of the method, the determination of the state of the needle mounted on the syringe is based on a comparison of the amplitudes and/or phases of the magnetic fields measured at two different locations, for example by means of two magnetic field sensors arranged offset from one another.

In a further embodiment variant, the method comprises converting the measured time profile of the magnetic field (in particular the magnetic field distribution) from the time domain into the frequency domain.

In a further embodiment variant, the method comprises determining the frequency components of the magnetic field (in particular the magnetic field distribution), for example by means of a Discrete Fourier Transform (DFT), at the rotational frequency of the injector, in particular also at double the rotational frequency of the injector.

In another embodiment of the method, the state of the needle is at least one of straight, bent, compressed, broken/fractured, coaxial with the longitudinal axis of the syringe, inclined relative to the longitudinal axis of the syringe, eccentric relative to the longitudinal axis of the syringe.

According to a further aspect of the invention, the means for checking the condition of the needle in the needle guard mounted on the syringe comprise one or more magnetic field sensors, in particular inductive sensors, fluxgate magnetometers, hall sensors, magnetoresistive sensors, for example AMR- (english "anisotropic magnetoresistive"), CMR- (english "ferromagnetic magnetoresistive"), GMR- (english "magnetoresistive") or TMR- (english "ferromagnetic magnetoresistive") sensors, for measuring the magnetic field (in particular the magnetic field distribution) around the needle.

In a further embodiment variant of the device, the magnetic field sensor or sensors are embodied as single-axis, two-axis or three-axis magnetic field sensors in order to determine the magnetic field (in particular the magnetic field distribution) in one, two or three dimensions.

In a further embodiment variant, the device further comprises a device for moving the needle relative to the one or more magnetic field sensors, in particular for rotating the syringe about its longitudinal axis and/or for moving the syringe along its longitudinal axis, or for moving the one or more magnetic field sensors parallel to the longitudinal axis of the syringe.

In another embodiment variant, the device further comprises one or more motors, such as servo motors or stepper motors, for rotating and/or longitudinally moving the injector, wherein a transmission is used, such that the rotational frequency of the one or more motors is a multiple or fraction of the rotational frequency of the injector.

In a further embodiment variant, the device also comprises an assembly with one or more permanent magnets and/or an assembly with one or more electromagnets (for example helmholtz coils) for generating the magnetic field, wherein the assembly in particular also has one or more iron cores.

In a further embodiment variant, the device further comprises a magnetic shield for suppressing interfering magnetic fields.

In a further embodiment variant, the device further comprises a comparison unit for comparing the magnetic field measured (in particular the measured magnetic field distribution) for the needle with the magnetic field measured (in particular the measured magnetic field distribution) for a reference syringe with a reference needle seated in a needle protection cap having a target state; and determining the status of the needle mounted on the syringe based on this comparison.

In a further embodiment variant of the device, the comparison unit is designed to carry out a comparison of the amplitude and/or phase of the magnetic field measured for the reference needle with the amplitude and/or phase of the magnetic field measured for the needle and to determine the state of the needle mounted on the syringe on the basis thereof.

In a further embodiment variant, the device further comprises a unit for carrying out a conversion of the measured time profile of the magnetic field (in particular of the magnetic field distribution) from the time domain into the frequency domain.

In another embodiment, the device further comprises an output, in particular for providing an output signal, configured for indicating the state of the needle as at least one of straight, bent, compressed, broken/fractured, coaxial with, inclined relative to, or off-centered relative to the longitudinal axis of the syringe.

In a further embodiment variant of the device, a plurality of magnetic field sensors are arranged vertically one above the other along an axis (in particular equally spaced), wherein the axis is arranged laterally parallel to the longitudinal axis of the syringe to be examined.

In a further embodiment variant, the device comprises a helmholtz coil consisting of two coaxially arranged coils, the coil axes of which are arranged horizontally in order to generate a magnetic field in the horizontal direction, wherein the injector is arranged between the two coils for examination.

It should be noted that combinations of the above-mentioned embodiment variants are possible, which in turn lead to specific embodiment variants of the invention.

Drawings

Non-limiting embodiments of the invention will be described in more detail below with the aid of the accompanying drawings. Wherein:

figure 1 shows an X-ray examination image of a syringe with a seated protective cap (according to the prior art) under which a bent needle is located;

fig. 2 shows an example of the field line course of the geomagnetic field (with an inclination of 64 °) around a curved injection needle made of steel;

FIG. 3 shows a schematic side view of an embodiment variant of the device according to the invention;

fig. 4 schematically shows a side view of another embodiment variant of the device according to the invention with helmholtz coils.

In the drawings, like reference numerals designate like elements.

Detailed Description

During the assembly of a medical injector, for example an insulin pump for single use, a needle or needle is placed on the injector or fixed thereto, for example glued, and a protective cap is then fitted into the needle. Here, the needle must enter into the material of the protective cap. Accordingly, the process is carried out with a certain force, so that the needle can bend, compress or break in this case, for example. These failures present multiple risks and therefore risk injury during use and/or sterile conditions are no longer present.

Fig. 1 shows an X-ray examination image of a syringe 1 with an optically opaque protective cap 3 placed, under which a curved needle 2 is located, as recorded in the method according to the prior art.

The following effects are utilized in the present invention: ferromagnetic materials affect the external magnetic field around them. Thus, ferromagnetic materials tend to draw magnetic fields into them. The field lines of the external magnetic field terminate on the surface of the ferromagnetic body and run inside it. Thus, the presence of an injection needle made of steel causes a local change in the course of the magnetic field lines. A perfect (i.e. straight) needle will cause a different change in the magnetic field lines than for example a needle with a kink.

Fig. 2 schematically shows an example of the field line course F of the geomagnetic field around a curved injection needle or needle 2. Depending on the latitude, the geomagnetic field slopes towards the ground to varying degrees. Thus, the geomagnetic field shown in fig. 2 has a downward inclination of 64 ° corresponding to the 47 th latitude. The magnetic field lines F are bundled by the injection needle 2 made of steel, and the field lines located further outside are deflected toward the injection needle 2. This deformation of the course of the field lines can be ascertained by measuring the magnetic field (in particular the magnetic field distribution) around the needle 2, in comparison with the straight needle 2. Based on the measurement of the magnetic field at one or more points, for example on or along the measuring path S, it can then be concluded whether the needle 2 is in a state, i.e. whether it has some kind of malfunction, e.g. a bend.

For measuring the magnetic field or the magnetic field distribution, one or more magnetic field sensors can be used, for example inductive sensors, fluxgate magnetometers, hall sensors, magnetoresistive sensors, for example AMR- (english "anisotropic magnetoresistive"), CMR- (english "ferromagnetic magnetoresistive"), GMR- (english "ferromagnetic magnetoresistive") or TMR (english "ferromagnetic magnetoresistive") sensors. These magnetic field sensors can be embodied as single-axis, two-axis or three-axis magnetic field sensors in order to determine the magnetic field or the magnetic field distribution in one, two or three dimensions. Here, the needle 2 can be moved relative to the one or more magnetic field sensors or, conversely, the one or more magnetic field sensors can be moved relative to the needle 2, for example vertically along the measuring path S, so that the magnetic field or the magnetic field distribution over the entire length of the needle 2 can be determined.

Fig. 3 shows a schematic side view of an embodiment variant of the device for examining injection needles according to the invention. The syringe 1 is clamped to the syringe in this caseIn the holder 5, the syringe holder is arranged on a rotary/rotational device 6, by means of which the syringe 1 can be rotated about its longitudinal axis a. By rotating, the needle 2 periodically changes the earth magnetic field around the needle 2. The earth magnetic field is generated by means of a magnetic field sensor system consisting of five magnetic field sensors 4₁、…、4₅Constructed magnetic field sensor assembly 4_AFor the determination, these magnetic field sensors are arranged vertically one above the other parallel to the longitudinal axis a of the syringe. Alternatively, a separate magnetic field sensor can also be used, which moves up or down along the measuring path S.

The time profile of the measured magnetic field is then converted into the frequency domain. This can be done for the individual frequencies, for example, by means of a discrete fourier transform. Particularly critical here is the rotational frequency of the injector 1 and its second harmonic (= double the rotational frequency). If the needle 2 has a bend, the magnetic field is directed towards the magnetic field sensor assembly 4 with each turn of the magnetic field by the bend_A(i.e., proximate the magnetic field sensor assembly) is deflected once, causing the magnetic field strength to periodically increase and decrease at the rotational frequency. Thus, the magnetic field distribution along the needle 2 has a greater maximum at this rotational frequency when the needle is bent than for a straight needle 2. Due to the bending, the magnetic field will also be out of phase compared to the straight needle 2. The state of the needle 2 can thus be deduced based on the magnitude and/or phase of the measured magnetic field, in particular when comparing it with a previously measured magnetic field around a perfect (i.e. straight) reference needle 2. As phase, two spaced apart magnetic field sensors 4 can also be used here_1…5(e.g. magnetic field sensor assembly 4)_ATwo adjacent magnetic field sensors 4_i&_i-1) The phase difference of the magnetic field.

Care should be taken to avoid disturbing magnetic fields during measurement. An electric servomotor, for example, thus generates such a disturbance field which is modulated with the rotational speed of the servomotor. In order to minimize its influence on the measurement, a transmission may be used, for example, so that the injector 1 is rotated many times faster or slower than the servomotor. If the rotational speed of the servomotor is, for example, as large as three times the rotational speed of the injector (i.e. a transmission ratio of 3:1), the magnetic field to be measured is hardly disturbed by the disturbing field generated by the servomotor at three times the rotational frequency of the injector 1 at the rotational frequency of the injector 1. Alternatively, a magnetic shield may also be used to suppress the disturbing magnetic field.

Instead of applying the earth magnetic field to the measurement, it is also possible to use a magnetic field formed by an assembly with one or more permanent magnets or an assembly with one or more electromagnets (for example helmholtz coils), wherein the assembly may in particular also have one or more iron cores. Thereby, for example, a very homogeneous magnetic field can be generated.

A schematic side view of this embodiment variant with a helmholtz coil is schematically shown in fig. 4. In this case, one coil 7 in each helmholtz coil pair₁、7₂Arranged to the left and right of the needle 2 to be examined. At two coils 7₁、7₂Forms a uniform horizontally-oriented magnetic field therebetween, which (as in fig. 3) can utilize the magnetic field sensor assembly 4_ATo be measured.

List of reference numerals:

1 Syringe

2 needle head and needle

3 needle head protective cap

4_1…5Magnetic field sensor

4_AMagnetic field sensor assembly with multiple magnetic field sensors

5 Syringe holder

6 rotating/rotating device (with lifting device possible)

7_1,2Helmholtz coil

a longitudinal axis of syringe

F magnetic field line

S sensor line, measurement path