U.S. patent application number 13/812541 was filed with the patent office on 2013-05-23 for device and method for determining the weight of pharmaceutical products by means of an x-ray source.
This patent application is currently assigned to ROBERT BOSCH GMBH. The applicant listed for this patent is lulian Maga, Werner Runft, Jens Schlipf, Martin Vogt. Invention is credited to lulian Maga, Werner Runft, Jens Schlipf, Martin Vogt.
Application Number | 20130129041 13/812541 |
Document ID | / |
Family ID | 43799022 |
Filed Date | 2013-05-23 |
United States Patent
Application |
20130129041 |
Kind Code |
A1 |
Runft; Werner ; et
al. |
May 23, 2013 |
DEVICE AND METHOD FOR DETERMINING THE WEIGHT OF PHARMACEUTICAL
PRODUCTS BY MEANS OF AN X-RAY SOURCE
Abstract
The invention relates to a device (10; 10a) for determining the
weight of pharmaceutical products (1), in particular of hard
gelatin capsules (3; 3a) filled with a pharmaceutical (2), by means
of an X-ray source (28), wherein the X-ray source (28) generates a
radiation cone (27; 36, 37) which passes through at least one
pharmaceutical product (1), and wherein a sensor element (30; 30a)
detects the radiation of the irradiated pharmaceutical product (1)
and supplies an evaluation device (32). According to the invention,
a reference object (35; 35a; 35b) is arranged in the beam path of
the radiation cone (27; 36, 37), wherein the radiation of the
X-rayed reference object (35; 35a; 35b) is detected by means of the
sensor element (30; 30a; 30b) and is supplied to the evaluation
device (32), and wherein the pharmaceutical product (1) and the
reference object (35; 35a; 35b) are positioned in relation to the
radiation cone (27; 36, 37) in an arrangement in which they do not
overlap each other in the radiation cone (27; 36, 37).
Inventors: |
Runft; Werner; (Winnenden,
DE) ; Maga; lulian; (Ludwigsburg, DE) ;
Schlipf; Jens; (Freiberg A. N., DE) ; Vogt;
Martin; (Schorndorf, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Runft; Werner
Maga; lulian
Schlipf; Jens
Vogt; Martin |
Winnenden
Ludwigsburg
Freiberg A. N.
Schorndorf |
|
DE
DE
DE
DE |
|
|
Assignee: |
ROBERT BOSCH GMBH
Stuttgart
DE
|
Family ID: |
43799022 |
Appl. No.: |
13/812541 |
Filed: |
April 13, 2011 |
PCT Filed: |
April 13, 2011 |
PCT NO: |
PCT/EP11/55817 |
371 Date: |
January 28, 2013 |
Current U.S.
Class: |
378/56 |
Current CPC
Class: |
G01N 2223/04 20130101;
B65B 1/46 20130101; G01N 23/087 20130101; B65B 3/003 20130101; G01N
2223/601 20130101; A61J 3/074 20130101; G01N 23/04 20130101; G01N
23/083 20130101; B65B 57/145 20130101; G01N 23/10 20130101 |
Class at
Publication: |
378/56 |
International
Class: |
G01N 23/04 20060101
G01N023/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 28, 2010 |
DE |
10 2010 038 544.1 |
Claims
1. A device (10; 10a) for determining the weight of pharmaceutical
products (1), by means of an X-ray source (28), wherein the X-ray
source (28) generates a radiation cone (27; 36, 37) which passes
through at least one pharmaceutical product (1), and wherein a
sensor element (30; 30a) detects radiation of the irradiated
pharmaceutical product (1) and supplies an evaluation device (32),
characterized in that a reference object (35; 35a; 35b) is arranged
in a beam path of the radiation cone (27; 36, 37), wherein
radiation of the X-rayed reference object (35; 35a; 35b) is
detected by the sensor element (30; 30a; 30b) and is supplied to
the evaluation device (32), and wherein the pharmaceutical product
(1) and the reference object (35; 35a; 35b) are positioned in
relation to the radiation cone (27; 36, 37) in an arrangement in
which the pharmaceutical product and the reference object do not
overlap each other in said radiation cone (27; 36, 37).
2. The device according to claim 1, characterized in that the
sensor element is an image recording sensor element (30; 30a;
30b).
3. The device according to claim 1, characterized in that a
material of the reference object (35; 35a; 35b) has a similar
atomic composition as the pharmaceutical product (1).
4. The device according to claim 1, characterized in that the
reference object (35; 35a; 35b) is arranged in the same plane (39)
as the pharmaceutical product (1).
5. The device according to claim 1, characterized in that the
reference object (35; 35a; 35b) has different thicknesses in a
plane perpendicular to the radiation cone (27; 36, 37).
6. The device according to claim 5, characterized in that the
reference object (35a, 35b) is designed wedge-shaped or in
steps.
7. The device according to claim 5, characterized in that the
reference object (35; 35a; 35b) produces a damping of x-radiation
which is greater at one location and smaller at one location than
the damping produced by the pharmaceutical product (1).
8. The device according to claim 5, characterized in that a surface
of the reference object (35; 35a; 35b) is perpendicularly aligned
to the radiation cone (27; 36, 37).
9. A method for determining the weight of pharmaceutical products
(1) by means of a device (10; 10a) according to claim 1,
characterized in that the pharmaceutical product (1) and the
reference object (35; 35a; 35b) are simultaneously radiographed by
means of the X-ray source (28), in that an image of an irradiated
pharmaceutical product (1) and of the reference object (35; 35a;
35b) are supplied to the evaluation device (32) by at least one
image recording sensor element (30; 30a), in that the evaluation
device (32) examines the irradiated pharmaceutical product (1)
pixel by pixel for a gray scale value thereof and associates the
same gray scale value on the reference object (35; 35a; 35b) and
thereby a thickness of said reference object (35; 35a; 35b) with
the gray scale value of the respective pixel, in that an average
thickness is subsequently determined across all of the pixels, in
that thereafter in knowledge of a number and surface area of the
pixels, a virtual volume of the pharmaceutical product (1) is
calculated; and in that in a final step, the virtual volume of said
pharmaceutical product (1) is multiplied by the thickness of said
pharmaceutical product (1) to determine the weight of said
pharmaceutical product (1).
10. The method according to claim 9, characterized in that in the
case of consecutive images, the gray scale values of the reference
object (35; 35a; 35b) are compared with each other and in the event
of a deviation, a correction factor is applied to the current gray
scale value.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to a device for determining the weight
of pharmaceutical products by means of an X-ray source. The
invention furthermore relates to a method for determining the
weight by means of a device in accordance with the invention.
[0002] A device is known from the German patent specification DE 10
2009 045 809 Al of the applicant. The known device comprises an
X-ray source, which serves to determine the weight of products
filled with a pharmaceutical, in particular in the form of hard
gelatin capsules. In this case, the pharmaceutical product is
X-rayed by the X-ray source and the radiation which penetrates the
pharmaceutical object is detected by means of an image recording
sensor element. An evaluation device of the aforementioned device
then determines a filling weight for the pharmaceutical product
from, e.g., the detected grey scale values of the image of said
pharmaceutical product. The disadvantage with this process is that
due to changing conditions, the values detected by the sensor
element vary from image to image for one and the same
pharmaceutical product. A concrete association of the image or
respectively gray scale values with a certain filling weight in the
capsule is thus made more difficult. In the case of consecutively
recorded images, changes of this kind can only be recognized at
locations whereat an unimpeded radiography is possible. The changes
cannot however thereby be unambiguously compensated, particularly
when detecting the filling weight by means of grey scale
values.
SUMMARY OF THE INVENTION
[0003] Based on the previously described prior art, the aim
underlying the invention is to further develop a device for
determining the weight of pharmaceutical products by means of an
X-ray source such that disturbances due to fluctuations in the
overall system as well as external disturbances can be detected and
compensated for, and therefore a particularly high degree of
accuracy with regard to determining the weight of the
pharmaceutical products is achieved. According to the invention,
the aim is met by a device for determining the weight of
pharmaceutical products by means of an X-ray source, said device
having the features of claim 1, in that a reference object is
arranged in the beam path of the radiation cone, wherein the
radiation of the irradiated reference object is detected and
supplied to the evaluation device, and wherein the pharmaceutical
product and the reference object are positioned in relation to the
radiation cone in an arrangement in which they do not overlap each
other in the radiation cone. That is to say when imaging or
respectively X-raying the pharmaceutical product, a reference
object is also always simultaneously X-rayed; and therefore in
combination with reference object, the items of image information
can be reliably associated with the gray scale values of the
pharmaceutical product even when fluctuations in the overall system
or those caused by external disturbances occur. A particularly
exact determination of the weight of the pharmaceutical product can
thereby be performed.
[0004] Advantageous modifications to the inventive device for
determining the weight of pharmaceutical products by means of an
X-ray source are specified in the dependent claims. All
combinations from at least two features disclosed in the claims,
the description and/or the figures fall within the scope of the
invention.
[0005] Provision is made in a preferred embodiment of the invention
for the sensor element to be designed as an image recording sensor
element. Using such an image recording sensor element, the
pharmaceutical product to be examined can be very easily divided up
into image points (pixels), from which items of information for the
evaluation device can be obtained via the gray scale values in
order to determine the weight of the pharmaceutical product.
[0006] An embodiment of the reference object, in which the material
of said reference object has a similar atomic composition as the
pharmaceutical product, is particularly preferred. The same
physical properties as for the pharmaceutical product thus result
when X-raying the reference object, and therefore the obtained
items of image information about the reference object can be used
directly for determining the weight of the pharmaceutical product
without complicated conversions or correction factors.
[0007] An embodiment of the invention is furthermore preferred, in
which the reference object is arranged in the same plane as the
pharmaceutical product. In so doing, preconditions for the
radiography which are at least approximately the same are created
for the reference object and the pharmaceutical product with
respect to the radiation cone or the X-ray radiation.
[0008] In order to be able to produce different gray scale values
on the recorded image by means of the reference object, provision
is made in a preferred manner for the reference object to have
different thicknesses in a plane perpendicular to the beam path of
the X-ray source. Different gray scales are produced by means of
said different thicknesses in the image of the X-rayed reference
object, which is detected by the sensor element.
[0009] Such gray scales can be constructively produced in a
particularly simple and reproducible manner by means of the
reference object if said reference object is designed in steps or
wedge-shaped. In this way, discrete gray scales can be achieved on
the image of the X-rayed reference object by means of a stepped
configuration, wherein the number of steps or respectively stairs
should be selected as large as possible in order to improve the
resolution or to increase the measuring accuracy. As an
alternative, a wedge-shaped reference object can also be used,
which continually produces varying gray scale values by means of
the wedge-shaped form thereof
[0010] In order to be able to evaluate all detected gray scale
values or respectively gray scale levels of the X-rayed
pharmaceutical product, provision is furthermore made in a
particularly preferred manner for the reference object to produce a
damping of the X-rays, which is larger at one location and smaller
at another location than the damping produced by the pharmaceutical
product. In so doing, it is ensured that all gray scale values
normally occurring when X-raying the pharmaceutical product are
covered by means of the reference object.
[0011] In order to maximize the individual steps of the reference
object or respectively the surface thereof in a stepped or
wedge-shaped configuration, provision is furthermore made in a
particularly preferred manner for the surface of the reference
object to be perpendicularly aligned to the radiation cone.
[0012] The invention also comprises a method for determining the
weight of pharmaceutical products by means of a device according to
the invention. Provision is thereby made for the pharmaceutical
product and the reference object to be simultaneously X-rayed by
means of an X-ray source, for an image of the X-rayed
pharmaceutical product and the reference object to be supplied to
the evaluation device by means of at least one image recording
sensor element, for the evaluation device to examine the X-rayed
pharmaceutical product pixel by pixel for the gray scale value
thereof, for the same gray scale value on the reference object and
thereby a thickness of the reference object to be associated with
the respective pixel, for a virtual volume of the pharmaceutical
product to be calculated thereafter in knowledge of the number and
the surface area of the pixels and in a final step with the aid of
the average thickness for the virtual volume of the pharmaceutical
product to be multiplied by the thickness of pharmaceutical product
in order to determine the weight of said pharmaceutical
product.
[0013] A method is particularly preferred, in which the gray scale
values of the reference object in consecutive images are compared
with each other. In the case of a deviation, a correction factor is
applied to the current gray scale values of the reference object.
It is thereby ensured that the device readjusts itself even in the
case of a lengthy operation thereof, in which parameters change as
a result of a change in the overall system or external
disturbances.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Further advantages, features and details of the invention
result from the following description of preferred exemplary
embodiments as well as on the basis of the drawings.
[0015] In the drawings:
[0016] FIG. 1 shows a simplified longitudinal section of a device
for determining the weight of hard gelatin capsules,
[0017] FIG. 2 shows a simplified top view of a device, which is
modified with respect to FIG. 1, utilizing reference objects
according to the invention,
[0018] FIGS. 3 and 4 show in each case simplified sections through
different embodiments of a reference object according to the
invention and
[0019] FIG. 5 shows an image of the device pursuant to FIG. 2,
which is recorded by means of an image recording sensor.
DETAILED DESCRIPTION
[0020] The same components or components having the same function
are provided with the same reference numerals in the figures.
[0021] In FIG. 1, the basic design of a device 10 for determining
the weight of pharmaceutical products 1 is depicted. The
pharmaceutical products 1 in this case relate particularly to hard
gelatin capsules filled with a pharmaceutical and as the case may
be with auxiliary substances or additives. It is however also
within the scope of the invention to determine the weight, e.g., of
tablets or something similar using the device.
[0022] The device 10 comprises an impeller 12 which is rotated in a
vertical axis of rotation in discrete steps and is only depicted in
part in FIG. 1. A plurality of receptacles, which receive
respectively one pharmaceutical product, are vertically aligned and
are designed as bore holes, are located on the upper side of said
impeller, wherein only one receptacle can be seen in FIG. 1. A
through bore-hole having a smaller diameter than the receptacle 13
is configured at the base of said receptacle 13.
[0023] During a standstill phase of said impeller 12, at least one
receptacle 13 is positioned beneath a tubular conveyor shaft 15 by
means of the progressively rotated impeller 12. On the side facing
the receptacle 13, the conveyor shaft 15 comprises a section having
a reduced diameter, the diameter of which is dimensioned such that
a hard gelatin capsule situated in the region of the section 16 is
in force-locking connection with said section 16, i.e. is clamped
in said section 16. Beneath the through-bore hole, an insertion
plunger 18 which moves up and down corresponding to the
double-headed arrow 17 is arranged on the side facing away from the
conveyor shaft 15. The hard gelatin capsule 3 situated in each case
in the receptacle 13 is pushed out of the receptacle thereof 13
over into a region above the section 16 of the conveyor shaft 15 so
that the impeller 12 can be further rotated in order to dispense
the next hard gelatin capsule(s) without the hard gelatin capsule
3, which was last pushed over into the conveyor shaft 15, falling
downwards out of said conveyor shaft 15 as a result of the weight
force thereof.
[0024] The conveyor shaft 15 has a cross section, which is adapted
to the cross section of the hard gelatin capsule 3 or rather
somewhat larger than this. In the exemplary embodiment, the
conveyor shaft 15 or respectively the longitudinal axis thereof is
vertically arranged together with the longitudinal axes 19 of the
hard gelatin capsules. A flap 22, which can be pivoted back and
forth corresponding to the double-headed arrow 21, is arranged at
the upper end of the conveyor shaft 15, said flap delivering the
respective hard gelatin capsule 3 that has been pushed out of the
conveyor shaft 15 either to a first discharge channel 23 or a
second discharge channel 24, depending on the position of the flap
22. In so doing, those hard gelatin capsules, which are evaluated
as "good" hard gelatin capsules 3, are conveyed further via the
first discharge channel 2; whereas those hard gelatin capsules 3,
which are evaluated as "bad" hard gelatin capsules 3, are conveyed
further via the second discharge channel 24.
[0025] The conveyor shaft 15 comprises a section 26 which is
permeable to x-radiation in a somewhat central region. The section
26 is radiographed by the radiation cone 27 of an X-ray source, the
central radiation axis of which is preferably but not restrictively
horizontally aligned, i.e. runs perpendicularly to the longitudinal
axis 19. A detector in the form of an image recording sensor
element 30, which is connected via a cable 31 to the evaluation
device 32, is arranged on the side of the section 26 opposite to
the X-ray source 28. The evaluation device 32 simultaneously serves
to at least indirectly actuate the position of the flap 22.
[0026] The weight of the pharmaceutical 2 in the hard gelatin
capsule 3 is determined by means of the X-ray source 28, the sensor
element 30 and the evaluation device 32 in combination with a
reference object 35, which is to be explained later in greater
detail and which cannot be seen in FIG. 1 because it is situated in
a plane perpendicular to the drawing plane of FIG. 1. Therefore
(besides if need be other criteria), the result serves the purpose
of distinguishing "good" hard gelatin capsules 3 from "bad" hard
gelatin capsules 3.
[0027] The modified device 10a depicted in FIG. 2 differs from FIG.
1 by the fact that the device 10a has two X-ray sources arranged
next to one another, the radiation cones 36, 37 of which in each
case simultaneously pass through a plurality of hard gelatin
capsules 3, in the exemplary embodiment respectively six hard
gelatin capsules 3, as well as in each case a reference object 35.
Two separate image recording sensor elements 30a are thereby
arranged on the side of the hard gelatin capsules 3 opposite to the
X-ray sources 28 so that each of the sensor elements 30a is
associated with an X-ray source 28.
[0028] Of course, it is also within the scope of the invention for
both X-ray sources 28 to use a common image recording sensor
element 30a.
[0029] The one reference object 35, which is associated with the
radiation cone 36, is situated in the top view at the left edge
region of the radiation cone 36, while the other reference object
35, which is associated with the radiation cone 37, is situated on
the right edge of the radiation cone 37. It can furthermore be seen
that the two reference objects 35 are located with respect to the
respective radiation cone 36, 37 in the same plane as the hard
gelatin capsules 3 to be radiographed. It is also important that
the arrangement of the reference objects 35 in the respective
radiation cone 36, 37 is configured in such a way that the
reference objects 35 and the hard gelatin capsules 3 do not overlap
each other.
[0030] Different embodiments of a reference object 35a, 35b are
depicted in FIGS. 3 and 4. The reference object 35a, 35b
advantageously consists of a material which has similar atomic
properties as the pharmaceutical product 1 to be radiographed, i.e.
particularly has the same damping properties for the x-radiation.
It can furthermore be seen that both reference objects 35a, 35b
have different thicknesses with regard to their cross sections.
Whereas the reference object 35a is thereby designed wedge-shaped,
the reference object 35b has a series of steps 38, which cause a
discrete change in the thickness of the reference object 35b.
Provision is preferably made for the damping (gray scale value) of
the reference object 35a, 35b to be greater at one location and
smaller at another location than the damping by means of the
pharmaceutical product 1. The arrangement or respectively the
alignment of said reference objects 35a, 35b with respect to the
radiation cone 36, 37 is furthermore configured in such a way that
said reference objects 35a, 35b are arranged perpendicularly to
their surface facing the X-ray source 28, i.e. perpendicularly to
the steps 38 of said reference object 35b or perpendicularly to the
base 40 of said wedge- shaped reference object 35a.
[0031] As is especially apparent in FIG. 2, the arrangement of the
reference object 35a, 35b in the respective edge region of the
radiation cone 36, 37 is therefore configured such that said
reference object 35a, 35b has to be disposed in each case somewhat
obliquely in order to facilitate the previously addressed
perpendicular radiographing or respectively X-raying of the
reference object 35a, 35b.
[0032] By means of the previously addressed geometric configuration
of the reference objects 35a, 35b, said objects have different
thicknesses, which produce different gray scale values at the
sensor element 30 when radiographing with the X-ray source 28. In
this connection, reference is made to FIG. 5, in which the images
of the device 10a pursuant to FIG. 2, which are recorded via two
sensor elements 30a, are depicted in a simplified manner. Both
reference objects 35b, which are configured in steps in the
exemplary embodiment depicted, can be seen on the left or the right
image edge. It is also apparent that the individual steps 38 have
different gray scale values. A plurality of hard gelatin capsules 3
containing the pharmaceutical 2, which likewise has a certain gray
scale value, can furthermore be seen in each respective section of
the image
[0033] The determination of the weight of the pharmaceutical 2
situated in a hard gelatin capsule 3 is explained below as follows:
An image of the reference object 35a, 35b is recorded in a
calibration process, which has previously taken place and is not
depicted, and the gray scale values thereof detected by the sensor
device 30, 30a are associated with the thicknesses of the reference
object 35a, 35b on the basis of the known geometric configuration
of said reference object 35a, 35b. In other words, this means that
a certain thickness of said reference object 35a, 35b at a certain
location is inferred on the basis of a certain gray scale value of
said reference object 35a, 35b. Furthermore, based on the known
geometry and the known material properties of said reference object
35a, 35b, a certain density can thereby be associated with a
certain gray scale value of said reference object 35a, 35b.
[0034] These gray scale values previously determined in the
calibration process as well as the geometric association thereof
with the reference object 35a, 35b are stored in the evaluation
device 32.
[0035] If, for example, the weight of the pharmaceutical 2 of the
hard gelatin capsule denoted in FIG. 5 with the reference numeral
3a is now detected or respectively checked, the image of the hard
gelatin capsule detected by the sensor element 30a is divided up
into individual image points (pixels). Each pixel represents a
certain surface area, for example a square having an edge length of
100 .mu.m. Then the detected gray scale value of the pixel is
associated with an (identical) gray scale value on the reference
object 35a, 35b for every pixel of the hard gelatin capsule. A
certain thickness can be associated with said gray scale value (on
the basis of the association of the thicknesses with the gray scale
values on the reference object 35a, 35b). After this process has
taken place pixel by pixel, an average thickness is determined from
the individual thicknesses. Said average thickness is now
multiplied by the overall number of pixels and the known surface
area thereof, and therefore a virtual volume of the pharmaceutical
2 can be determined. With knowledge of the density of the
pharmaceutical 2, the weight of the pharmaceutical 2 situated in
the hard gelatin capsule 3a can finally be determined from the
virtual volume.
[0036] It is also essential for an image of the relevant reference
object 35a, 35b to be recorded in each case at the same time that
the pharmaceutical product 1 is being x-rayed. In so doing, changes
in the gray scale values on the reference object 35a, 35b can be
determined on temporally consecutive images. Said changes can occur
as a result of disturbances in the system or as a result of
external interferences. Should, for example, it be determined that
the gray scale value of the reference object 35b changes at a
certain step, the evaluation device 32 can then subject said
detected, current gray scale value to a correction factor, which
adapts the current gray scale value to the original gray scale
value and consequently compensates for the interferences.
[0037] The devices 10, 10a described to this point can be altered
or modified in many ways without deviating from the thought
underlying the invention. It is, however, important for the image
of a reference object 35, 35a, 35b to in each case be
simultaneously recorded when measuring the weight of the
pharmaceutical product 1, said image being used to determine the
weight of the pharmaceutical product 1. It is thus, for example,
conceivable for the pharmaceutical products 1 not to be
radiographed in a direction which runs perpendicularly to the
longitudinal axis 19 thereof. The reference object 35, 35a, 35b can
also basically be arranged in any position in the beam path of the
X-ray source 28.
* * * * *