A method of establishing the presence of specific substances in milk and an implement for applying the same

<img file="NL1010540C2_D0001.tif" />

Office for Industrial Property The Netherlands © 1010540 © C OCTROOI²⁰

<td>©) Patent application: 1010540 © Filed: 12.11.1998</td><td>© Int.CI⁷A01J5 / 013</td>

<td>© Registered:</td><td>© Patent holder (s):</td>

<td> 15.05.2000</td><td>Maasland NV in Maasland.</td>

<td>@ Date:</td><td>© Inventor (s):</td>

<td> 15.05.2000</td><td>Karei van den Berg in Bleskensgraaf</td>

<td>© Published:</td><td>Helena Geralda Maria Vijverberg in Schiedam Wilhelmus Johannes Adrianus van Lier in Delft</td>

<td>03.07.2000 IE 2000/07</td><td>© Authorized representative: Ir. MJFM Corten in 3155 PD Maasland.</td>

Method for determining the presence of certain substances in milk and device for applying this method.

A method for determining the presence of certain substances in the milk and a device for applying this method, wherein one or more sources irradiate successively or simultaneously with radiation of different wavelengths and / or intensities and one or more receivers reflect and / or determine absorbed radiation intensities over a time interval.

NL C1010540

<img file="NL1010540C2_D0002.tif" />

The contents of this patent correspond to the original filed description with claim (s) and any drawings.

METHOD FOR DETERMINING THE PRESENCE OF CERTAIN SUBSTANCES IN MILK AND APPARATUS FOR USING THIS METHOD

The invention relates to a method for determining the quality and / or composition of milk by measurements.

Such a method is known from German Offenlegungschrift 27 59 126 which describes a light source which irradiates the milk and which describes a photosensitive element with which the color change of the milk is determined. If the milk shows a different color, for example due to the presence of blood or pus, the milk is separated and collected in a separate reservoir. This method has the drawback that only gross deviations in the color of the milk can be detected and that subtle color differences, for example due to the presence of small impurities or because the animal has eaten grass instead of concentrates, are not detected.

An alternative method is known from document NL 1004980. Herein a method is described with which the intensity values ​​of a number of colors in the milk are determined and wherein the milk comes from separate animals. By comparing the intensity values ​​with the values ​​recorded during previous milking sessions, the presence of certain substances such as impurities is determined. This method has the drawback that the intensity values ​​of the milk vary greatly depending on the amount of ambient light. In addition, the results cannot be interpreted quantitatively, as only changes with regard to previous milkings are recorded.

Finally, document NL 9402010 describes a sensor for detecting contamination in the milking system of a milking machine using radioactive radiation or ultrasonic sound. The drawback of this sensor is that it is only suitable for detecting contamination in the milk and cannot perform other qualitative measurements on the milk such as detecting blood, detecting mastitis or determining the cell count.

The object of the invention is to eliminate or at least minimize the above-mentioned drawbacks. According to the invention, this is achieved in that one or more sources irradiate the milk one after the other or simultaneously with radiation of one or more different wavelengths and / or different intensities, while, for at least part of the time the sources are switched on, one or more receivers determine one or more reflected and / or absorbed radiation intensities during a time interval; that the values ​​of the radiation intensities thus obtained are stored in a memory; that the values ​​are compared with each other as well as with previous values ​​recorded during one or more previous measurements and that the results of this comparison process are made known. Since the sources irradiate the milk simultaneously or successively during the measurements with radiation of different wavelengths and / or different intensities and the different reflected and / or absorbed radiation intensities are determined during a time interval, it is achieved that color changes are observed over a wider wavelength range. This has the advantage that subtle color changes can be observed, such as in the presence of small amounts of blood, pus, flushing liquid or urine in the milk. Another advantage of irradiating the milk with a source is that the determined radiation intensities are not disturbed by the presence of sources in the environment, such as, for example, the lamps in the stable or the sunlight.

During a measurement, one or more sources may be turned off, while, for at least part of the time the sources are turned off, one or more receivers detect one or more reflected and / or absorbed radiation intensities during a time interval; that the values ​​of the radiation intensities thus obtained are stored in a memory as background values; that the background values ​​are processed in the values ​​obtained during the period that one or more sources are switched on; that the values ​​adjusted by the background values ​​are stored in a memory. In this way, the radiation intensity of the background is determined. This makes it possible to correct the radiation intensities that are measured when the sources are switched on. In a preferred embodiment, the time intervals for determining the reflected and / or absorbed radiation intensities are constant. In this way it is achieved that the determined radiation intensities for one or more receivers can be easily compared. One or more values ​​of one or more determined reflected and / or absorbed radiation intensities can be stored in a memory, so that the values ​​can be compared with previously obtained values.

One or more ratios of the values ​​are determined on the basis of the values ​​of the determined radiation intensities. A calibration value is the moving average of the values ​​and / or ratios of the values ​​obtained for a given animal during a defined number of last milkings that have taken place. A calibration value can also be formed by one or more measurements on a calibration agent such as a transparent liquid, reference sheet, calibration rod, white paper, white tile, flushing liquid or water. The values ​​can also be compared with previous calibration values. In a preferred embodiment, the values ​​and / or ratios of values, both mutually and with previous values ​​and / or calibration values ​​and / or ratios recorded during one or more previous measurements, are compared and the results of this comparison process are made known. According to an inventive feature, the results of the comparison process are displayed in such a way that the presence and / or concentration of certain substances, such as impurities in the milk, can be read directly from this.

According to a further feature of the invention, one or more further receivers directly receive the radiation from the source and the value of the first receiver is adjusted using one or more values ​​from the further receivers. In this way, the intensity of the radiation emitted by the source can be determined. When the source ages, which is important not only with radioactive sources but also with incandescent lamps, or when pollution is present at the source, the intensity of the radiation will decrease. This influences the value of the determined radiation intensity. This value can be corrected by the value of the determined radiation intensity of the further receiver. One or more ratios of values ​​can also be adjusted by values ​​of one or more further receivers that directly receive the radiation from the source.

In a preferred embodiment, one or more sources and one or more receivers are coupled to a periodic signal, such as a block signal or a sawtooth signal, wherein one or more receivers determine the radiation intensity when one or more sources have reached substantially constant intensity. The periodic signal ensures that the sources and the receivers are synchronized. The source is first switched on, after which the receiver determines the radiation intensity. Many sources have a warm-up time before a constant or maximum intensity is reached. After the warm-up time has elapsed, the radiation intensity can be determined by the receiver. The sources can also be directly turned on by the periodic signal.

According to another feature of the invention, one or more sources comprise light sources emitting radiation of one or more discrete wavelengths, which wavelengths are related to the absorption characteristic of certain substances in the milk, such as proteins or fats, and provide one or more receivers the radiation intensity is determined, and the presence and / or concentration of one or more substances in the milk is determined. This ensures that the milk is irradiated with radiation of a wavelength that is absorbed by certain substances in the milk. By comparing the intensity of the emitted radiation with the determined radiation at the receiver, the absorption of the light of a certain wavelength can be determined. This not only demonstrates the presence of a certain substance, but also determines the concentration of that substance.

According to an inventive feature, the measurement of the milk composition comprises determining the presence and / or amount of one or more of the following substances: blood, urine, manure, pollution, coliforms, hormones, flakes, flushing liquid, air . All of these substances can be determined by measuring the reflected and / or absorbed radiation from the source. In addition, the measurement also includes determining the fat content and / or the cell count and / or mastitis and / or colostrum and / or grass milk.

In a preferred embodiment, the measurements are carried out on milk from individual animals. In this way it is possible to check the quality of the milk of an individual animal. When the animal is in heat, or is in a bad condition due to illness, this can be detected in time. The measurements can also be made on milk from separate udder quarters. The values ​​and / or ratios of values ​​can be compared with each other as well as with previous values ​​and / or values ​​of different udder quarters, and the results of this comparison process can be made known . In this way, for example, milk with blood or pus from an udder quarter can be separated in time before this milk is mixed with milk from the other quarters.

According to a further feature of the invention, one or more measurements are taken when the flow sensor indicates that the milk is flowing. In this way it is achieved that measurements are carried out during milking. In a preferred embodiment, one or more sources comprise light sources which, successively or simultaneously, irradiate the milk with light of a red color, a green color, a blue color, and are switched off. According to a further inventive feature, the ratios RG, RB and GB of the determined radiation intensities are calculated as RG = (ra) / (ga), RB = (ra) / (ba),

GB = (ga) / (ba) where r is the determined radiation intensity while the milk is irradiated by one or more sources of light of a red color; g is the determined radiation intensity while the milk is irradiated by one or more sources of light of a green color, b is the determined radiation intensity while the milk is irradiated by one or more sources of light of a blue color and a is the determined radiation intensity while one or more light sources are switched off.

The ratios RG, RB and GB can be multiplied by correction factors that depend on the calibration values. These calibration values ​​can again come from measurements on reference liquids. Also, the ratios can be multiplied by the values ​​of the radiation intensities determined by the further receivers directly receiving the radiation from the light source.

In a further embodiment, the feed of an animal is determined on the basis of a measurement of the milk. It can be determined by measuring the milk that, for example, the color green is more strongly present. This is an indication that the animal has eaten grass instead of the usual portion of concentrates.

In addition to a method, the invention also relates to a device for applying the method shown here for determining the quality of milk by measurements. To this end, the device is characterized in that it is provided with a color measuring system which is provided with one or more sensors comprising one or more sources for irradiating the milk with radiation of one or more different wavelengths and / or different intensities, while, during at least part of the time that the sources are switched on, one or more receivers determine the radiation intensity during a time interval. One or more sources may be turned off while, for at least part of the time the sources are turned off, one or more receivers determine the radiation intensity during a time interval. These sensors can be located in different places in the milk system,

10105 40 wherein the sources each emit radiation of a different wavelength and / or intensity. However, the sources can also be located in the same place, in which case the sources can be switched on, for example. One or more sources can emit phase-modulated or frequency-modulated radiation. This has the advantage that the signal from the source is less disturbed by the environment. One or more receivers can be equipped for this purpose with demodulation means. The demodulation means may comprise a filter, such as an active filter or an optical filter.

According to another feature of the invention, one or more sources comprise one or more light emitting diodes (LEDs) that emit one or more colors of light. An example of such a multi-color LED is the LF95EMBGMBC from manufacturer Kingbright. In a preferred embodiment, one or more LEDs are turned on with a periodic signal, such as a sawtooth signal or a block signal. The frequency of the periodic signal is greater than or equal to the time it takes for the source to reach a constant and / or maximum intensity. In this way, a warm-up time after switching on the source is avoided.

According to another feature of the invention, one or more receivers comprise a photodiode or a photosensitive resistor or a photomultiplier or a phototransistor or a PIN diode. A suitable receiver is the optical sensor with built-in amplifier TSL250. In a suitable embodiment, one or more receivers are provided with shielding means. These shielding means serve to shield the receiver from radiation coming directly from the source. In another embodiment, one or more sensors are provided with one or more further receivers which receive the radiation from the LED directly. One or more LEDs can be provided with a ground lens, a diffuse lens or a ground lens.

According to an inventive feature, one or more sources and one or more receivers are placed side by side or at a distance less than the diameter of the milk line. In this way, the signal from the source can easily reach the receiver. According to another feature of the invention, one or more sources and one or more receivers are placed opposite one another. In that case, the receivers determine the radiation absorbed by the milk. One or more sensors can also be placed in the milk, or on the wall of, or in one or more milk lines. Finally, one or more sensors can be placed in a milk glass.

According to another feature of the invention, the sensor is coupled to a flow meter. In this way it can be achieved that measurements are, for example, only made on flowing milk. According to another characteristic, the calibration of the device is done hardware-wise and / or software-wise. The advantage of this is that coarse settings can be done hardware-wise and fine adjustments based on previously determined values ​​and / or calibration values ​​can be done software-wise.

According to a final feature of the invention, the invention also comprises a milking implement provided with a milking robot, characterized in that the milking implement is provided with an implement as described here and / or which is suitable for applying one or more methods as described here. In this way, the color measuring system can be used to monitor the quality of the milk. This is important because during fully automatic milking someone is not continuously present to visually check the quality of the milk.

The invention will now be explained in more detail with reference to the accompanying figures.

Figure 1 shows a milk system provided with the color measuring system;

Figure 2 shows a milk line on which a sensor is mounted;

Figure 3 shows an alternative embodiment for the sensor;

Figure 4 shows another embodiment for the sensor.

Figure 1 shows four teat cups 1 to be connected to the teats of an animal to be milked, of which the milk lines 2 open into a milk glass 3. A vacuum line 15 is further connected to the milk glass 3 for inserting in the milk glass 3 itself, in the milk discharge hoses 2 and to apply a negative pressure in the teat cups 1, necessary to keep the teat cups connected to the teats of the animal, to be able to milk and to separate milk and air contained therein in the milk glass 3. From the milk glass 3, the milk obtained is discharged via a tap 4, a pump 5, a non-return valve 6 and a three-way cock 7 over a pipe 8 to a milk tank (not further shown).

The figure furthermore shows a color measuring system 9, which measuring system comprises a processing unit 10 to which four color sensors 11 are connected. These sensors 11 are preferably arranged on the milk lines 2 of the individual teat cups 1. In other embodiments, the sensors 11 can also be arranged in the milk glass

11 in the milk or in an overflow tray 14. The processing unit records the measured values ​​from the sensor. These measured values ​​can be passed on to a computer for further processing 12.

Figure 2 shows a sensor 11 which is received in a milk line 2. The sensor 11 consists of a light source 16 and a receiver 17, arranged together in a housing 19. The receiver 17 is provided with shielding means, so that only the reflection of light from the light source 16 on the milk is received by the receiver 17. The housing 19 is preferably of such a design that the light source and the receiver are shielded from ambient light. In a preferred embodiment, the light source is a multi-color LED with which the milk can be irradiated with different colors of light. The LED can be controlled with a periodic signal, such as a block signal or a sawtooth signal. The receiver can also be coupled to this signal, so that both the source and the receiver are synchronized. Whenever the source reaches a constant intensity, the reflected and / or absorbed amount of radiation is determined by the receiver.

Figure 3 shows a sensor in which the receiver 17 is placed opposite the source 16. In this case, the quality of the milk is measured by means of the absorption of radiation of different wavelengths. The absorption amount of light of certain wavelengths is then a measure of the presence and / or concentration of certain substances in the milk. Both the source and receiver are in a separate housing.

Figure 4 finally shows an alternative embodiment in which a further receiver 18 is arranged in the sensor that directly measures the radiation from the source. In this way, the intensity of the radiation emitted by the source can be determined. When the source becomes obsolete, or when pollution is present on the source, the intensity of the radiation will decrease. This influences the value of the determined radiation intensity. This value can be corrected by the value of the determined radiation intensity of the further receiver.

<img file="NL1010540C2_D0003.tif" />