JP4718094B2 - Injector cartridge encoding - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a code represented by a plurality of bars whose code is read by a read head when the bars are illuminated.
[0002]
[Prior art]
Such cords can be used in the cartridges of infusion devices such as syringes and pumps.
[0003]
Patients who have to receive frequent injections often use so-called pen injectors, whereby the required amount can be dispensed from the injector cartridge. When empty, the cartridge can be replaced with a new one. Another possibility is to use so-called pumps, whereby very small amounts are injected at short intervals. The pump also obtains liquid injection from a replaceable cartridge in the pump.
[0004]
The cartridge must be printed with information that clarifies the contents of the cartridge. This information can be printed directly on the cartridge or on a label adhered to the cartridge. In addition, it is desirable for the cartridge to have a code that defines a special identification value for the cartridge and its contents, which can be automatically read by a code reader. Such a code reader is suitably attached to a syringe or pump that uses the cartridge so that the code is automatically read when the cartridge is attached to the infusion device. This displays information on the contents of the cartridge on the display, or allows the medication contained in the cartridge not directed or defined by the infusion device to be rejected.
[0005]
In order to be able to visually inspect the contents of the cartridge, such cartridges are mainly made of a transparent material and the label with printed text and code must be at least partially transparent. The printed text leaves some white space between letters and lines, and the text need not cover the entire cartridge surface.
[0006]
The difference is coding. To illustrate the problem, considering a commonly used cartridge, it has the shape of a cylindrical glass tube, one end of which is closed by a thin film through which the needle can penetrate, through which the liquid in the cartridge is passed. Can be extruded by pushing a piston closing the other end of the tube.
[0007]
[Problems to be solved by the invention]
The cord is usually provided as a barcode having a bar extending perpendicular to the longitudinal axis of the cartridge. In order to ensure that the code is read safely, the maximum contrast between the bar and the space is targeted. The bar is therefore a black opaque line. A reader in the infusion device reads this code when the cartridge is passed axially into the device. However, if the rotational position of the cartridge is not carefully observed during cartridge installation, it cannot be ensured that the bar of code will pass the reading range of the reader. This problem can be solved by extending the bar around the entire circumference of the cartridge, but it makes it difficult to visually inspect the contents of the cartridge at the part covered by the bar code. The cord area is limited to about 1 cm and is limited to the position where the piston is located when the cartridge is fully filled so that no inspection is required in this area.
[0008]
For bar codes available on the market that use normal printing technology on the label, the smallest basic module corresponding to the narrowest bar or the smallest space is about 0.2 mm. Even with this good basic module, the 1 cm space only leaves space for very limited information. Ordinary bar codes require a large number of start and end bits, which is sufficient to inform the reader that the bar code and more than one check bit are being read, thereby making the code insensitive to noise. By providing such redundancy, the amount of information is further reduced.
[0009]
Another cause of failure that makes it impossible to use the good basic module described above is that it is difficult to wrap the label around the cartridge sufficiently accurately. Where the label edges reach the end of the bar, they may be displaced by a few tenths of a millimeter with respect to each other. This requires a coarser basic module of the bar code so that no error occurs when the bar code is read along the opposite lines of the edges on both sides of the label.
[0010]
An object of the present invention is to describe a mechanically readable code to identify the labeled contents of the cartridge, thereby preventing or mitigating the aforementioned problems of the code.
[0011]
[Means for Solving the Problems]
This object is achieved by a code represented by a plurality of bars and read by the read head when the bars are illuminated with light. In this code, the bar is almost transparent, and optical gratings that diffract and reflect light incident on the surface having the code are provided along its entire length, respectively, and a small portion of the incident light is a set of light beams. And at least one of the set of light beams reflects the presence of the bar and the presence of information stored in the bar when the bar is illuminated by the reading light. It is selected to be detected to indicate.
[0012]
The cartridge has a code represented by a plurality of bars that are substantially perpendicular to the longitudinal axis of the cartridge. The bars are mainly transparent and each is provided with an optical grating along its entire length that diffracts light incident on the surface with the code, so that a small portion of this light is reflected from the bar surface as a set of light beams and diffracted. And at least one of the set of light beams is selected to be detected to indicate the presence of the bar as the bar passes through the read light field.
[0013]
Reading can be done by continuous bar illumination as the bar passes through the reader during cartridge insertion in a device that uses such a cartridge.
[0014]
When the bars are almost transparent, they may be distributed over the entire length of the cartridge without interfering with visual inspection of the cartridge contents, so that the good space provided is more information and between the bars. Can be used to give large space. The large bars and the large space between the bars reduce the accuracy requirements of the readhead optical portion, thereby allowing an inexpensive readhead configuration.
[0015]
The light grating need not form an integral structure covering the bar. Bars consist of spaced strips, dots or small islands that have a grid and fill the bar area, where the spacing between strips, dots or small islands is less than the minimum dimension of the reading light field.
[0016]
The orientation of the grating lines varies from bar to bar, whereby the plane defined by the set of diffracted interference beams from the different bars has a different orientation.
If each bar is chosen to have a grid with one of two defined directions, the reflection from the band will be interpreted as representing "1" and "0" in binary code it can.
[0017]
When two defined directions of grid lines are used, the two directions are approximately perpendicular to each other and are oriented on the bars to form a 45 ° angle with the edges of these bars.
[0018]
The grating can be formed as a good reflection line on the bar or by a fold in the bar area of the material surface with the bar.
[0019]
The pleats may be provided as alternating ridges and grooves in the bar area on the surface of the material having the bars.
[0020]
The cross section of the pleat can have the form of a sine wave, a square wave or a sawtooth wave.
[0021]
The bar may be a rotationally symmetrical ampoule with a bar having a band shape distributed over the entire length of the cartridge and extending around the circumference.
[0022]
In particular, when the cartridge is formed of a plastic material, the lattice is formed on the surface of the cartridge itself, but a label may be attached to the cartridge.
[0023]
Although the code has been described in connection with its use with a medical device cartridge, it may optionally be used when a normal bar code is visually impaired or interferes with the inspection of the part having the code.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.
FIG. 1 schematically shows a cartridge formed as a cylindrical ampule 1, which is provided with a plurality of spaced bands 2, 3, 4, 5 along its length, which band of this ampule. Each ampoule extends around the entire periphery of the ampoule perpendicular to the vertical axis, and has a structure that forms an optical grating. The orientation of the grid on individual bands varies from band to band. However, in the example shown, the orientation of the band grid is one of two defined orthogonal directions that form an angle of 45 ° with the band edge or the generatrix of the cylindrical cartridge. Bands 2, 3, 5 are oriented in one of two defined orthogonal directions, and band 4 is oriented in the other of the orthogonal directions.
[0025]
In this example, the two main directions are selected to obtain a binary code, but more possible directions can be selected to obtain a code with a higher base number. With the two main directions, the orthogonal orientation is selected to obtain the maximum discrimination between the reflected beams representing “0” and “1”. An angle of 45 ° with the bus is chosen so that the detector can obtain a convenient position.
[0026]
The light grating on the band is given by the material surface of the cartridge or the shape of the label folds that adhere to the cartridge. The pleats can be made so that the cross section of the grating has the square wave shape shown in FIG. 2, which schematically illustrates the manner in which ridges 6 and grooves 7 are provided on the surface. Furthermore, an aspect in which an incident light beam arriving in one direction indicated by an arrow 8 is diffracted in different directions indicated by an arrow 9 is schematically shown. Because the cartridge material and its possible labels are transparent, most of the incident light passes through without being diffracted, but a small portion of the light that passes through the grating structure on the surface is diffracted and a small portion of the light that is incident on the surface Is diffracted in the direction indicated by arrow 9. These directions representing first, second, third, etc. orders of diffraction can be calculated based on the wavelength of the incident light and the dimensions of the grating using the following equations.
nsinθ = dλ
Where n is the beam order, d is the distance between the lines of the grating, and λ is the wavelength of the incident light. While the use of monochrome light ensures a well-defined beam, the use of white light is recognized to make each beam look like a rainbow fan.
[0027]
If a waveform having a sawtooth-shaped cross section is used as shown in FIG. 3, the incident light is indicated by the incident light arrow 8 and the reflected interference light beam arrow 9. Thus, the incident beam is reflected only in the side surface direction of one surface. With this type of grating, the directions of the two gratings representing “0” and “1”, respectively, can be rotated 180 ° with respect to each other, where 90 ° is due to the grating having the shape shown in FIG. Be maximized.
[0028]
FIG. 4 shows the cartridge portion viewed from the direction of incident light. The band extending around the entire circumference of the cartridge is provided with a grating having a ridge orientation on the surface as indicated by line 11 in that direction. A portion of the light beam incident on the band surface of area 12 is diffracted by a plane beam indicated by line 13. Due to the grating perpendicular to the grating indicated by line 11, the diffracted beam is seen in the plane indicated by the dashed line. Each planar detector 15, 16 is positioned such that they can each detect a diffracted interference beam of a selected order from the band. If the grating of the band in question is oriented as shown in FIG. 4, the interfering beam is incident on detector 15, while the interference from a band having a grating orthogonal to the grating shown. The beam causes a resonant beam to enter the detector 16. Thus, a signal from one detector can represent “0” and a signal from another detector can represent “1”. Signals generated simultaneously from both detectors indicate that both detectors are incident due to diffuse reflection from the surface of the cartridge outside the band, and signals that are not from the detector are absorbed or not absorbed by the light beam. It indicates that the light is incident on a non-reflective area.
[0029]
With the code described, the signal from one of the detectors 15 or 16 or the signal from only one of them indicates that the band belonging to the code is passing through the detector. In a sequence of bars and spaces to detect light changes caused by alternating bars and spaces of variable width and to inform the reader that the code is about to be read by a normal bar code forming information It is necessary to start. Without such a start code, random changes in light can be misinterpreted as information.
[0030]
In FIG. 5, a single band is a dot with a light grating as long as the diameter of the read light field covering the space between the area 12 and the dot 17 is configured so that at least one dot is covered by the light field. The aspect comprised by 17 is shown. Individual regions are shown here as circular dots, but may also be strips or small islands with regular or irregular shapes. If any part of the area with the grating is located in the reading light field, the signal is received by one of the detectors 15 or 16.
[0031]
The light source and detector are electronic components designed to be mounted on a circuit board. However, the light source should be positioned so that the incident light beam is approximately perpendicular to the surface having the code to be read, and the detector is arranged so that the selected diffracted light beam is incident on them. Should be. To meet these requirements, a read head 20 as shown in FIG. 6 is provided. The read head 20 is made of a transparent material and can be attached to the circuit board 21 and has a surface 22 from which light is transmitted to and received from a code read by the reader. The read head shown in FIG. 6 is provided with holes 23 which are important for the light beam path of the source beam and holes 24 and 25 which are important for the diffracted and reflected beam.
[0032]
FIG. 7 shows a cross-sectional view of the read head. In this figure, an output window 26 of the light source and an input window 27 to one of the detectors can be seen. On the output window 26 of the light source, a hole 28 is provided in the material of the read head 20, and the hole is confined upward by a surface 29 perpendicular to the direction of the light from the light source, through which light is diffracted. Pass without. The light beam impinges on the inclined surface 30 at the bottom of the hole 23 and is reflected as a horizontal beam perpendicular to the surface 22. The photodetector is similarly mounted in a hole in the circuit board 21, which is defined in the upward direction by a surface parallel to the circuit board, on which an inclined surface is provided at the bottom of the holes 24 and 25. . However, here the path of the beam is the opposite and the beam diffracted through the surface 22 is reflected by the inclined surface at the bottom of the holes 24 and 25 and is finally directed downwards to be incident on the detector. . A hole 31 is provided to form an opening for the light beam from the light source to form a suitable light spot in the code bar.
[0033]
FIG. 8 shows the manner in which the read head, light source and detector are mounted on the opposite side of the circuit board, with the read head 20 on the circuit board 21 showing that there is a totally reflecting surface 32 at the bottom of the hole 24. This surface 32 guides the reflected and diffracted beam in the direction of the detector 33.
[0034]
FIG. 9 shows a side cross-sectional view of the read head 20 mounted on the circuit board 21, showing the path of the light beam. The light beam 34 from the light source 35 is emitted from the output window 26 of the light source, passes through the surface 29, is incident on the surface 30, is reflected, and passes through the surface 22 of the read head so as to impinge on the code read on the cartridge 38. pass. Based on the concavo-convex pattern direction of the bar of the read code, the reflected and refracted beam 39 is directed towards the total reflection surface at the bottom of one of the holes 24 or 25. The beam 39 shown in FIG. 9 is a beam that is diffracted in the direction of the total reflection surface at the bottom of the hole 25 not shown, by which the beam is directed to the input window 27 of the detector 40.
[0035]
FIG. 10 shows a top view of the read head of FIG. 9, where the diffracted beam from the code on the cartridge 38 is diffracted in the direction of the hole 24 and the bottom of this hole for entry into the input window of the detector 33. It shows that the light is reflected by the total reflection surface 32. This possible diffracted beam is shown as dashed line 41. Note that because the beams 39 and 41 do not enter the surface 22 perpendicularly, they are slightly refracted as they pass through this surface.
[0036]
The signals from the two detectors of reflected and diffracted light are used to detect codes encoded in the holographic field.
[0037]
A typical set of signals from two detectors is shown in FIG.
[0038]
The purpose of the detection system is to extract code information from the detector signal.
[0039]
There are two fundamentally different detection principles. That is,
1. Mainly hardware-based systems,
2. Mainly with software-based systems.
[0040]
[Hardware-based system]
Hardware-based detection systems operate by using a fixed detection threshold for each channel so that any signal below this level is a “low” level and any signal above this level The signal is at a “high” level.
[0041]
The thresholded signals from the two detection channels 0 and 1 are analyzed for a valid signal by using the XOR principle, i.e., if there is a valid signal, only one channel is "high". “There is a level signal. This state is detected by the hardware part representing the XOR gate, and the output from this gate is used to inform the microprocessor, for example, that a valid signal is present by the generation of a clock signal. This is shown in FIG.
[0042]
When the microprocessor receives the clock signal, it reads the value of the detector's 0 and 1 signals and from this determines the corresponding value of the code bit.
[0043]
Software-based system
Software-based systems operate by converting two analog signals from the photodetector to digital form and then analyzing the stored signal in digital form. This is illustrated in FIG.
[0044]
The analog signals from detectors 0 and 1 are preferably sent to analog to digital converters AD0 and AD1, which are included in the system microprocessor. The AD converter converts the data into a digital form.
[0045]
When data is recorded, a code detection algorithm is used to extract code information embedded in the detector signal. The use of software-based systems places a very high demand on the microprocessor when compared to hardware-based systems, but opens up the possibility of using further developed detection principles. This includes suppression and filtering of noise in the detector signal, compensation for the changing sensitivity of the detector, and the like.
[Brief description of the drawings]
FIG. 1 is a schematic view of an ampoule provided with a band extending around a periphery where an optical grating is provided.
FIG. 2 is a schematic diagram of a cross section of an optical grating given by a square wave waveform on the surface.
FIG. 3 is a schematic view of a cross section of an optical grating provided by a surface sawtooth waveform.
FIG. 4 is a schematic diagram showing a state in which a light beam incident on a band having an optical grating is reflected and diffracted.
FIG. 5 is a diagram corresponding to FIG. 4 in which the band is configured by dots having an optical lattice.
FIG. 6 is a perspective view of a read head attached to a circuit board.
7 is a perspective view corresponding to FIG. 6 with the read head cut in half. FIG.
8 is a phantom diagram of FIG.
FIG. 9 is a view corresponding to FIG. 7 in which an optical path is shown.
10 is a plan view of FIG. 9. FIG.
FIG. 11 is a graph of an ideal detector signal.
FIG. 12 is a schematic diagram of a primarily hardware-based detection system.
FIG. 13 is a schematic diagram of a primarily software-based detection system.

Claims (13)

In a cartridge for an infusion device, which is formed as a cylindrical ampule having a vertical axis, and attached with a cord composed of a plurality of bars extending perpendicularly to the vertical axis ,
The bar is substantially transparent, it is provided each light grating that reflects diffract light incident on the surface fitted with a code along the entire length of the bar, the light of a small portion of the incident light is a set of It reflected from the bar surface as the light beam is diffracted, at least one of the set of light beams and the presence of the bar when the bar is illuminated by the light beam, the information stored in the bar Selected to detect ,
Wherein each bar of the light grating comprises lines having a predetermined direction, the cartridge according to the predetermined direction is selected as one of at least two predetermined directions, characterized in Rukoto. Bar of the code has an optical grating, strip having a plurality of intervals that fills the realm of the bar, dot, or are composed of small islands, the strip, the spacing between the dots or small islands 2. A cartridge according to claim 1, wherein the cartridge is smaller than the minimum dimension of the reading light field. 3. Cartridge according to claim 1 or 2, characterized in that the direction of the lines of the optical grating varies from bar to bar, whereby the different bars define different directions of the diffracted beam set. The direction of the lines of the light grating is selected such that each bar has a light grating having one direction of two defined directions, so that the reflection from the bar is a binary code "1" and 4. The cartridge according to claim 1, wherein the cartridge is interpreted as representing "0".   The cartridge according to claim 4, wherein the two directions are orthogonal to each other. Two directions cartridge according to claim 5, wherein Rukoto respectively to form an angle of bar edge and 45 °. 7. A cartridge according to claim 1, wherein the light grating is formed by a pleat on the surface of the material of the bar area.   8. A cartridge according to claim 7, wherein the pleats are formed as alternating ridges and grooves in the bar region of the surface of the material supporting the bar. 9. The cartridge according to claim 8 , wherein a cross section of the pleat has a square wave shape. 9. A cartridge according to claim 8 , wherein the cross-section of the pleat has a sawtooth wave shape.   The cartridge according to any one of claims 1 to 10, wherein the bars are distributed over the entire length of the cartridge. Bar is any one cartridge according to claims 1 to 11, characterized in that it has a band shape that extends over the entire circumference of the cartridge. 13. The cartridge according to claim 1, wherein the bar is provided on a label bonded to the cartridge.

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