Body composition analysis apparatus and method for animals

Abstract

The present invention relates to a body composition analysis apparatus and method and, more specifically, to a body composition analysis apparatus and method for animals, which can analyze overall body compositions such as body fat, muscle mass, and body moisture level of animals with high reliability through a simple measurement process by a dual sensor unit that is provided with a near-infrared light source capable of measuring a subcutaneous fat ratio and an electrode capable of measuring bioimpedance.

Description

Body composition analysis device and method for animals

[0001] The present invention relates to a body composition analysis device and method, and more particularly, to a body composition analysis device and method for animals, which enable a high degree of reliability in analyzing the overall body composition of an animal, such as body fat, muscle mass, and body water level, through a simple measurement process using a dual sensor unit equipped with a near-infrared sensor capable of measuring subcutaneous fat ratio and a constant current electrode and measurement electrode capable of measuring bioimpedance.

[0002] The common body composition evaluation methods include traditional methods such as the anthropometric method of measuring skinfold thickness, the body circumference method, and the body mass index measurement, and the classical standard method of measuring body fat, the underwater body density method. However, these measurement methods have a problem in that the reproducibility varies somewhat depending on the skill of the measurer, making it difficult to maintain the reliability of the measurement results at a constant level.

[0003] In addition, methods for measuring body composition using indirect measurements include magnetic resonance imaging, computerized tomography, and dual energy X-ray absorptiometry (DEXA), and methods for measuring body water (Isotope Dilution) and body potassium (Whole-Body Potassium Count) are used as gold standards. However, these methods are expensive because they require expensive measuring equipment, and they are not suitable for treatment and prevention through periodic measurements, so they are mainly used only in a limited manner in the research stage.

[0004] However, among these methods, bioimpedance measurement is widely used because it is non-invasive, safe because it does not use radiation, has a short measurement time, can be performed inexpensively and easily using simple equipment, and has high reliability in measurement results.

[0005] These various methods of analyzing body composition can be applied equally to animals, including companion animals such as dogs and cats, which have similar body compositions as humans. However, in the case of animals, there is a problem in that it is difficult to maintain a stable measurement posture for a certain period of time, so additional measures such as anesthesia must be used.

[0006] In addition, when applying the bioimpedance measurement method to animals, there was a problem in that it was difficult to obtain accurate measurement results because the constant current applied for impedance measurement could not be directly applied to the epidermis of the skin due to the large amount of body hair on the animal's body.

[0007] Accordingly, technologies have been proposed that introduce devices that can apply a constant current to areas of the animal's body with little hair, such as the feet or nose, or devices that can forcibly restrict the animal's movement while measurement is being performed.

[0008] However, these conventional measuring devices do not measure while the animal maintains a natural posture, but rather target unwanted areas for measurement convenience or force the animal into an uncomfortable posture with limited movement. Therefore, there is a problem that continuous measurement is difficult, and it is difficult to secure the reliability of the measured values ​​due to changes in the animal's posture.

[0009] The present invention provides a body composition analysis device and method for animals, which can analyze the overall body composition of an animal, such as body fat, muscle mass, and body water level, with high reliability through a simple measurement process using a dual sensor unit equipped with a near-infrared light source capable of measuring subcutaneous fat ratio and an electrode capable of measuring bioimpedance.

[0010] The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0011] According to one embodiment of the present invention for solving the above-described problem, a body composition analysis device for an animal may include a dual sensor unit in which a near-infrared sensor for irradiating near-infrared rays to the skin of an animal and a constant current electrode for applying an alternating current to the skin of the animal are exposed together on one surface of a housing so as to be in contact with the skin of the animal as a measurement target; a subcutaneous fat analysis unit for detecting the amount of near-infrared rays reflected within skin tissue after being irradiated from the near-infrared sensor to the skin of the animal and calculating a subcutaneous fat ratio; an impedance measurement unit for calculating bioimpedance using a current applied from the constant current electrode to the skin of the animal and then received by a measurement electrode; and a body composition analysis unit for analyzing and providing body composition including body fat mass, muscle mass, and body water content of the animal as a measurement target by matching the bio-information of the animal to the subcutaneous fat ratio and the bioimpedance.

[0012] At this time, the dual sensor unit includes a near-infrared sensor installed in the inner space of the plate-shaped plate and irradiating near-infrared rays of a preset wavelength; and an impedance sensing unit installed on the outer periphery of the near-infrared sensor and applying an alternating current having a preset frequency; and the near-infrared sensor may include a first light source irradiating near-infrared rays of a center wavelength of 900 to 940 nm, a second light source irradiating near-infrared rays of a center wavelength of 940 to 1040 nm, and a photodetector that receives light reflected from inside skin tissue after being irradiated to the skin of an animal from the first light source or the second light source.

[0013] In addition, the near-infrared sensor may further include a shielding wall that blocks the movement of light between the first light source and the second light source and the photodetector; and a transparent window that covers the upper part of the near-infrared sensor where the first light source and the second light source and the photodetector are arranged.

[0014] In addition, the impedance sensing unit includes a constant current electrode that contacts the skin of the animal and applies an alternating current having a constant frequency to the skin of the animal; and a measuring electrode that measures a voltage dropped as the alternating current passes through the skin of the animal; and the constant current electrode and the measuring electrode may be formed as pin-shaped electrodes that protrude outward higher than the upper end of the near-infrared sensor on a plate-shaped plate.

[0015] In addition, the impedance sensing unit may be arranged symmetrically around the outer periphery of the near-infrared sensor, with at least one constant current electrode and one or more measuring electrodes each forming a group.

[0016] In addition, the impedance sensing unit may form an electrode group in which one constant current electrode and one measuring electrode form a pair, and at least one or more paired electrode groups may be arranged at equal intervals around the near-infrared sensor.

[0017] In addition, the subcutaneous fat analysis unit may include a light source control unit that determines the wavelength and amount of near-infrared light to be irradiated to the skin tissue of the animal, and controls the near-infrared light to be irradiated from the first light source and the second light source at a constant time difference; and a light amount analysis unit that calculates the ratio of the absorption rate of the second light source to the absorption rate of the first light source based on the amount of light detected by the photodetector, and then calculates the subcutaneous fat ratio of the animal based on the calculated absorption rate ratio.

[0018] In addition, the light source control unit may control the first light source to irradiate near-infrared rays having a center wavelength of 900 to 940 nm for testing, set the light quantity of the first light source as a reference value on a lookup table provided in advance based on the light quantity of the near-infrared rays irradiated from the first light source and received by the photodetector, and determine the light quantity of the second light source corresponding to the light quantity of the first light source as the reference value using the lookup table, and then control the second light source to irradiate near-infrared rays.

[0019] In addition, the impedance measuring unit may include a constant current output control unit that controls the application of an AC constant current having a certain frequency to the skin tissue of the animal from the constant current electrode and measures the voltage dropped while reacting with the skin tissue at the measuring electrode; and an impedance calculation unit that compares the voltage value measured at the measuring electrode with the AC constant current value applied from the constant current electrode to detect the voltage phase and the current phase, detects the phase difference based on the detected phase difference, and calculates the bioimpedance of the animal using the detected phase difference.

[0020] In addition, the constant current output control unit can sequentially generate an AC constant current having at least three different frequencies centered on 50 KHz and apply the generated AC constant current to the constant current electrode, and control the measurement of a voltage value measured at the measurement electrode in response to each AC constant current having a different frequency.

[0021] In addition, a method for analyzing body composition of an animal according to another embodiment of the present invention may include a step of determining a wavelength and light quantity of near-infrared light to be irradiated to skin tissue of the animal, controlling to irradiate near-infrared light from a first light source and a second light source with a predetermined time difference, and calculating a subcutaneous fat ratio of the animal using a ratio of an absorption rate of the second light source to an absorption rate of the first light source based on the amount of light detected by a photodetector; a step of generating an alternating current having a predetermined frequency and then controlling to apply it to skin tissue of the animal from a constant current electrode, and calculating a bioimpedance of the animal by measuring a voltage dropped while reacting with the skin tissue at a measurement electrode; and a step of analyzing and providing a body composition including body fat mass, muscle mass, and body water content of the animal as a measurement target by matching the bioinformation of the animal to the subcutaneous fat ratio and bioimpedance.

[0022] At this time, in the step of calculating the subcutaneous fat ratio of the animal, a near-infrared ray having a center wavelength of 900 to 940 nm is irradiated from a first light source, and based on the amount of near-infrared ray irradiated from the first light source and received by the photodetector, a look-up table prepared in advance is used to set the light amount of the first light source, which serves as a reference value, and after determining the light amount of the second light source corresponding to the light amount of the first light source, which serves as the reference value, using the look-up table, a near-infrared ray having a center wavelength of 940 to 1040 nm can be irradiated from the second light source.

[0023] In addition, in the step of calculating the bioimpedance of the animal, an alternating current having at least three frequencies centered on 50 KHz is sequentially generated and applied to the constant current electrode, and the voltage value measured at the measuring electrode corresponding to each alternating current having a different frequency can be measured.

[0024] In addition, in the step of calculating the bioimpedance of the animal, the phase difference between the voltage phase and the current phase is detected using the voltage measured at the measuring electrode for each of the plurality of alternating currents applied from the constant current electrode, and then the arithmetic average of the detected phase differences can be determined as the phase difference to be applied to calculate the bioimpedance.

[0025] According to the various embodiments of the present invention as described above, there is an effect that allows for a high degree of reliability in analyzing the overall body composition of an animal, such as body fat, muscle mass, and body water level, through a simple measurement process using a dual sensor unit equipped with a near-infrared sensor capable of measuring subcutaneous fat ratio and a constant current electrode capable of measuring bioimpedance.

[0026] In addition, the present invention has the effect of easily performing body composition analysis of an animal simply by bringing the dual sensor unit into close contact with the animal's body, by forming a pin-shaped electrode with a constant current electrode and a measurement electrode protruding from the outer periphery of a near-infrared sensor located at the inner center.

[0027] In addition, the present invention has the effect of improving the reliability of contact with skin tissue by applying an alternating current to the animal's skin tissue for impedance measurement and the measuring electrode being a pin-shaped electrode protruding above the near-infrared sensor, thereby improving the accuracy of the bioimpedance calculated by removing or pressing the animal's body hair during measurement.

[0028] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0029] Figure 1 is a diagram showing the overall configuration of an animal body composition analysis device according to the present invention.

[0030] Figure 2 is a detailed block diagram of an animal body composition analysis device according to the present invention.

[0031] Figure 3 is an example diagram of the arrangement of a dual sensor unit according to the present invention.

[0032] Figure 4 is a configuration diagram of a near-infrared sensor according to the present invention.

[0033] Figure 5 is an example of a measurement performed on a near-infrared sensor according to the present invention.

[0034] Figure 6 is a graph of the absorption rates of biological moisture and fat for near-infrared wavelengths.

[0035] Figure 7 is an example of an electrode array of an impedance sensing unit according to the present invention.

[0036] Figure 8 is an example of a measurement method for measuring body composition by contacting an animal's body according to the present invention.

[0037] Figure 9 is a flow chart of a body composition analysis method for animals according to the present invention.

[0038] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be assigned the same reference numbers, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably solely for the convenience of writing the specification, and do not in themselves have distinct meanings or roles.

[0039] In addition, when describing the embodiments disclosed in this specification, if it is determined that a detailed description of a related known technology may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention.

[0040] Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0041] When an element is referred to as being "connected" or "connected" to another element, it should be understood that it may be directly connected or connected to that other element, but that there may be other elements in between. Conversely, when an element is referred to as being "directly connected" or "connected" to another element, it should be understood that there are no other elements in between. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0042] In this specification, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0043] Referring to FIGS. 1 to 8 below, an embodiment of an animal body composition analysis device according to the present invention will be specifically described.

[0044] Fig. 1 is a block diagram of a body composition analysis device for animals according to the present invention, and Fig. 2 is a detailed block diagram of a body composition analysis device for animals according to the present invention.

[0045] Referring to FIGS. 1 and 2, a body composition analysis device (10) for animals according to the present invention may include a dual sensor unit (100) in which a near-infrared sensor that irradiates near-infrared rays to the skin of an animal and a constant current electrode that applies an alternating current to the skin of an animal are exposed together on one surface of a housing so as to be in contact with the skin of an animal to be measured, a subcutaneous fat analysis unit (200) that detects the amount of near-infrared rays reflected within skin tissue after being irradiated from the near-infrared sensor to the skin of the animal to calculate a subcutaneous fat ratio, an impedance measurement unit (300) that calculates bioimpedance using a current applied from the constant current electrode to the skin of the animal and then received by a measurement electrode, and a body composition analysis unit (400) that analyzes and provides body composition including body fat mass, muscle mass, and body water content of an animal to be measured by matching the bioinformation of the animal to the subcutaneous fat ratio and the bioimpedance.

[0046] The above dual sensor unit (100) is installed together on one side of a housing that can be held by a person in order to bring the near-infrared sensor and the constant current electrode into contact with the skin of the animal that is the measurement target, as shown in FIG. 8.

[0047] The above dual sensor unit (100) may include a near-infrared sensor (110) installed in the inner space of a plate-shaped plate and irradiating near-infrared rays of a preset wavelength, and an impedance sensing unit (120) installed on the outer periphery of the near-infrared sensor and applying an alternating current having a preset frequency.

[0048] As illustrated in FIG. 3, the above-described dual sensor unit (100) may have the near-infrared sensor (110) installed in the center of the inner side of a circular plate, and the impedance sensing unit (120) installed in the outer space around it. However, this is merely an example, and the shape of the plate may be implemented differently, and the positions where the electrodes forming the near-infrared sensor and the impedance sensing unit are arranged are not limited to the form illustrated in FIG. 3.

[0049] The above-described near-infrared sensor (110) may include, as illustrated in FIG. 4, a first light source (NIR light source A) (111) that irradiates near-infrared rays having a center wavelength of 900 to 940 nm, a second light source (NIR light source B) (112) that irradiates near-infrared rays having a center wavelength of 940 to 1040 nm, and a photodetector (113) that receives light reflected from inside skin tissue after being irradiated onto the skin of an animal from the first or second light source.

[0050] In addition, the near-infrared sensor (110) may further include a shielding wall (114) that blocks the movement of light between the first light source and the second light source and the photodetector to minimize the light irradiated from the first light source or the second light source from reacting with the animal's skin tissue and being received by the photodetector.

[0051] In addition, a transparent window (115) may be further provided to cover the upper portion of the near-infrared sensor in which the first and second light sources and the photodetector are arranged, thereby minimizing contamination by foreign substances and not hindering the transmission of light irradiated from the first and second light sources.

[0052] In Fig. 4, (a) represents a side view of a near-infrared sensor, and (b) represents a plane view of the near-infrared sensor. As illustrated in Fig. 4 (a), the light irradiated from the first or second light source (112) is blocked from entering the photodetector (113) by the shielding wall (114), thereby minimizing the influence of the light irradiated from the first and second light sources on the amount of light measured by the photodetector without reacting with skin tissue.

[0053] That is, as shown in (b) of FIG. 4, the near-infrared sensor (110) has a first light source (NIR light source A) (111) and a second light source (NIR light source B) (112) that emit near-infrared rays of different wavelengths positioned together on one side of the shielding wall (114), and a photodetector (113) positioned on the other side of the shielding wall (114). At this time, since the emission of near-infrared rays by the first light source and the second light source is controlled with a time difference by the control of the light source control unit described later, even if they are positioned together in the same space, the wavelength of light irradiated onto skin tissue can be maintained constant.

[0054] The near-infrared light emitted from the first or second light source is irradiated onto the skin tissue of the animal being measured, and as illustrated in Fig. 5, it reacts with the epidermis, dermis, subcutaneous tissue, muscles, etc. and is absorbed or reflected. Then, the photodetector measures the amount of light reflected rather than absorbed by the skin tissue.

[0055] In general, the rate at which near-infrared light is absorbed by body water and fat varies depending on the wavelength of the near-infrared light, as shown in the absorption rate graph in Figure 6. That is, near-infrared light with a center wavelength of 920 nm is absorbed maximally by fat, and near-infrared light with a center wavelength of 980 nm is absorbed maximally by water, but is absorbed relatively minimally by fat.

[0056] That is, as shown in Fig. 6, it can be confirmed that the near-infrared light with a center wavelength of 920 nm has a high absorption rate in fat (shown as a dotted line in Fig. 6), and the near-infrared light with a center wavelength of 980 nm has a high absorption rate in water (shown as a dashed line in Fig. 6).

[0057] Accordingly, it can be confirmed that the low-fat triceps (LOW-FAT TRICEP) has a high absorption rate when irradiated with near-infrared rays having a center wavelength of 980 nm (illustrated by a dashed line in FIG. 6), but the high-fat triceps (HIGH-FAT TRICEP) has a relatively low absorption rate compared to the low-fat triceps even when irradiated with near-infrared rays having a center wavelength of 980 nm (illustrated by a solid line in FIG. 6).

[0058] In addition, the impedance sensing unit (120) includes a constant current electrode (121) that contacts the skin of the animal and applies an alternating current having a constant frequency to the skin of the animal, and a measuring electrode (122) that measures the voltage dropped as the alternating current passes through the skin of the animal, and the constant current electrode (121) and the measuring electrode (122) are formed as pin-shaped electrodes that protrude outward higher than the upper end of the near-infrared sensor (110) on a plate-shaped plate.

[0059] It is difficult to directly apply the conventional plate-shaped electrode for measuring human impedance to animals due to the long and dense body hair that surrounds the entire body. Accordingly, the impedance sensing unit (120) forms the constant current electrode and the measuring electrode as pin-shaped electrodes protruding from the upper part of the plate, so that when the measurer presses the impedance sensing unit against the animal's body, the pin-shaped electrodes protruding from the upper part of the plate press against the body hair, thereby allowing the electrodes to come into closer contact with the skin.

[0060] As shown in FIG. 7, the above impedance sensing unit (120) can be arranged to form various electrode arrays along the outer periphery of the near-infrared sensor (110) located at the center of the plate.

[0061] In Fig. 7, a positive electrode (+) is shown at the top and a negative electrode (-) is shown at the bottom, and (a) shows an embodiment in which one constant current electrode (121) and one measuring electrode (122) are provided, (b) shows an embodiment in which two constant current electrodes (121) and two measuring electrodes (122) are provided, (c) shows an embodiment in which three constant current electrodes (121) and three measuring electrodes (122) are provided, and (d) shows an embodiment in which four constant current electrodes (121) and four measuring electrodes (122) are provided.

[0062] At this time, as the number of constant current electrodes and measurement electrodes provided in the impedance sensing unit increases, the number of electrodes that come into direct contact with the body without being blocked by densely grown body hair increases, thereby improving the accuracy of measurement.

[0063] In addition, in (b) to (d) of FIG. 7, an embodiment is illustrated in which the constant current electrodes and the measuring electrodes are each grouped and arranged symmetrically around the outer periphery of the near-infrared sensor, but this is not limited thereto, and it is of course possible to implement such that one constant current electrode and one measuring electrode together form a pair of electrode groups, and at least one or more paired electrode groups are arranged at equal intervals around the near-infrared sensor.

[0064] In addition, it goes without saying that the above-mentioned constant current electrode and the measuring electrode may be arranged in various shapes, such as an oval, circle, or polygon, along the perimeter of the near-infrared sensor on the plate-shaped plate forming the above-mentioned dual sensor unit.

[0065] The above-mentioned subcutaneous fat analysis unit (200) may include a light source control unit (210) that determines the wavelength and light quantity of near-infrared rays to be irradiated to the skin tissue of the animal and controls the near-infrared rays to be irradiated from the first light source and the second light source at a constant time difference, and a light quantity analysis unit (220) that calculates the ratio of the absorption rate of the second light source to the absorption rate of the first light source based on the light quantity detected by the photodetector, and then calculates the subcutaneous fat ratio of the animal based on the calculated absorption rate ratio.

[0066] To this end, the light source control unit (210) may include a first converter (DAC) that controls the wavelength and amount of near-infrared light irradiated from the first light source, and a second converter (DAC) that controls the wavelength and amount of near-infrared light irradiated from the second light source. In addition, the light source control unit (210) may further include a near-infrared (NIR) measurement circuit that measures the amount of near-infrared light received from the photodetector.

[0067] Accordingly, the light source control unit (210) transmits the wavelength and light quantity of the near-infrared ray irradiated from the first light source or the second light source, and the light quantity of each near-infrared ray measured by the photodetector, to the central processing unit (400) so that they can be used for body composition analysis.

[0068] The above light source control unit (210) first controls the first light source (111) to testly irradiate near-infrared rays having a center wavelength of 900 to 940 nm. Then, based on the amount of near-infrared rays irradiated from the first light source and reflected from skin tissue and received by the photodetector (113), the light amount of the first light source (NIR light source A) that serves as a reference value is set on a look-up table (NIR light source A / B light amount reference LUT) that is provided in advance.

[0069] At this time, since the central wavelength of the near-infrared light irradiated from the first light source has already been determined, the light quantity of the first light source, which serves as a reference value, can be set using the lookup table. That is, when the light quantity of the first light source received by the photodetector is insufficient, the reference value of the first light source can be set using the lookup table so that the light quantity of the first light source increases.

[0070] In addition, the light source control unit (210) can determine the light quantity of the second light source (NIR light source B) corresponding to the light quantity of the first light source, which is the reference value, using a lookup table (LUT), and then control the second light source to irradiate near-infrared rays.

[0071] At this time, the light source control unit (210) can measure the light quantity by converting the light quantity of the near-infrared light received by the photodetector into a current signal based on the responsiveness according to the wavelength of the near-infrared light and the incident light power (P), and converting it into a voltage signal using a current and voltage (IV) conversion circuit. In addition, the responsiveness according to the wavelength of the near-infrared light can be expressed as a current value per watt (A / W) according to the wavelength of the near-infrared light.

[0072] In addition, the light quantity analysis unit (220) can calculate the subcutaneous fat ratio based on the ratio of the absorption rate of the first light source absorbed in skin tissue and the absorption rate of the second light source absorbed in skin tissue by using the light quantity of the near-infrared light received by the photodetector after the near-infrared light is irradiated from the second light source (112).

[0073] At this time, if the animal's skin tissue is in a high-fat state, the absorption rate for the second light source is measured to be high, and if the animal's skin tissue is in a low-fat state, the absorption rate for the second light source is set to be relatively low. Therefore, the light quantity analysis unit can calculate the subcutaneous fat ratio using the ratio of the absorption rate for the first light source, which is the reference, and the absorption rate for the second light source.

[0074] In addition, the impedance measuring unit (300) may include a constant current output control unit (310) that controls the application of an AC constant current having a certain frequency to the skin tissue of an animal from the constant current electrode and measures the voltage dropped while reacting with the skin tissue at the measuring electrode, and an impedance calculating unit (320) that compares the voltage value measured at the measuring electrode with the AC constant current value applied from the constant current electrode to detect the voltage phase and the current phase, detects the phase difference based on this, and then calculates the bioimpedance of the animal using the detected phase difference.

[0075] At this time, the constant current output control unit (310) sequentially generates an AC constant current having at least three different frequencies centered on 50 KHz and applies the generated AC constant current to the constant current electrode so that a multi-frequency measurement method can be applied, and the voltage value measured at the measurement electrode can be measured in response to each AC constant current having a different frequency.

[0076] In the above impedance calculation unit (320), the phase difference can be detected using the voltage measured at the measurement electrode corresponding to each alternating current having a different frequency applied to the constant current electrode, and the impedance of the animal can be calculated based on the detected phase difference.

[0077] In this way, the impedance measurement unit (300) can overcome the problems and limitations of a single-frequency measurement method by using an AC constant current having multiple frequencies, and can also measure the animal's bioimpedance multiple times using an AC constant current of the same frequency, and determine the average value of the impedance values ​​calculated accordingly as the animal's bioimpedance.

[0078] Typically, bioimpedance is measured by utilizing differences in the electrical conductivity of skin tissue. That is, current flows along the area with the lowest impedance and highest conductivity, and impedance, a factor that impedes the flow of alternating current, is frequency-dependent.

[0079] This impedance (Z) is composed of the sum of resistance (R) and reactance (Xc) measured at a specific frequency, as shown in the following mathematical expression 1. The resistance (R) component corresponds to a non-conductive component that impedes the flow of current when an alternating current is passed through the body, and the reactance (Xc) component affects the flow of alternating current as an effect of capacitance generated in structural forms such as cell membranes or boundaries of biological tissues.

[0080] [Mathematical Formula 1]

[0081]

[0082] In addition, in body composition analysis, the subject of measurement can be assumed to be a cylinder, and in this case, as in mathematical equation 2 below, the resistance (R) of the cylinder can be obtained by multiplying the equation that is inversely proportional to the cross-sectional area (A) and proportional to the length (L) by the resistivity (ρ). In addition, the volume (V) of the cylinder can be obtained by multiplying the cross-sectional area and the length.

[0083] [Equation 2]

[0084]

[0085] Afterwards, by modifying the mathematical formula for calculating the resistance of a cylinder to express the cross-sectional area in terms of length and resistance and then substituting it into the mathematical formula for calculating the volume, the following mathematical formula 3 can be derived for estimating the volume of a cylinder based on the relationship between resistance, length, and resistivity.

[0086] [Equation 3]

[0087]

[0088] At this time, the reactance (Xc) has a small value and has little effect on the impedance value, so the body resistance of the measurement target can be used as an approximate value of the impedance, as in the following mathematical expression 4.

[0089] [Equation 4]

[0090]

[0091] The cylindrical model, which is the subject of impedance measurement, can be viewed as a homogeneous conductor, and the height of the subject (Height) corresponds to the length of the cylinder (L), and the resistance value (R) can be obtained through measurement. Through this process, the body water content of the subject's living body can be estimated, and since a certain portion of the lean body mass (FFM: Fat Free Mass) is known to be body water, the estimated body water content can be used to calculate lean body mass.

[0092] In general, low-frequency currents cannot pass through cells due to the capacitive properties of the cell membrane in body impedance, but high-frequency currents can pass through the cell membrane, and the impedance can be measured as the sum of the intracellular and extracellular fluid components.

[0093] In addition, conductivity is proportional to the amount of water and electrolytes, and decreases as the shape of the cell approaches a sphere. Fat tissue has cells that are close to a sphere in shape, contain little water, and have very low electrical conductivity due to the insulating nature of fat itself, so fat is a tissue with relatively high impedance.

[0094] In contrast, fat-free tissue has a high water content of 72-74% and contains electrolytes, so it has high electrical conductivity, and tissues other than fat have lower impedance than fat tissue, and since body water is the component of a living body that passes current well, by contacting the constant current electrode and the measuring electrode with the skin tissue of the animal to be measured, and then passing an alternating current through the constant current electrode and measuring the voltage at the measuring electrode, the volume of body water can be estimated.

[0095] In order to measure the impedance of a living body, an alternating current is applied to the living body, and the applied alternating current has frequency characteristics. Conventionally, a single frequency method (Single frequency BIA, SF-BIA) was used to estimate total body water using only 50 kHz alternating current. In the bioimpedance measurement using 50 kHz alternating current, the weighted sum of the resistance of extracellular water (ECW) and intracellular water (ICW) rather than the total body water (TBW) was measured.

[0096] However, the single frequency measurement method has the disadvantage of being able to estimate total body water because the frequency of the alternating current that penetrates the thin cell membrane is around 50 kHz, so low-frequency current below that has low cell permeability and flows along the extracellular water, and high-frequency current over 100 kHz has high cell permeability and flows through the cell membrane, but cannot distinguish between intracellular fluid and extracellular fluid, and the accuracy decreases when water accumulation is severe. Therefore, the single frequency measurement method has the limitation that it is difficult to measure the difference from intracellular water (ICW) although it can estimate fat-free mass (FFM) and total body water (TBW).

[0097] Accordingly, the impedance measurement unit (300) can be controlled to measure bioimpedance using both low and high frequencies by applying a multi-frequency measurement method (Multi frequency BIA, MF-BIA) that complements the shortcomings of the single-frequency measurement method.

[0098] For multi-frequency methods, multiple frequencies, typically ranging from 1 kHz to 1 MHz, are used to measure and evaluate lean body mass (FFM), total body water (TBW), intracellular water (ICW), and extracellular water (ECW). Thus, multi-frequency bioimpedance measurement is used to evaluate the ratio of intracellular water (ICW) to extracellular water (ECW), with lower frequencies below 50 kHz used to measure the extracellular compartment, and higher frequencies above 200 kHz used to distinguish and measure intracellular and extracellular fluids separately.

[0099] In addition, for practical measurements, the volume of total body water (TBW) is obtained using low-frequency current, the volume of extracellular water (ECW) is obtained using low-frequency current, and the volume of intracellular water (ICW) is obtained by subtracting the volume of extracellular water (ECW) from the volume of total body water (TBW).

[0100] The elements calculated by measuring bioimpedance are largely divided into body fat mass (FM) and fat-free mass (FFM). Among these, fat-free mass (FFM) can be divided into bone mass, extracellular water (ECW), intracellular water (ICW), and protein. In general, the remainder after subtracting bone mass is divided into body cell mass (BCM).

[0101] In this way, an alternating current is applied to the skin tissue of the animal to be measured through the constant current electrode (121) provided in the impedance sensing unit, and the voltage is measured at the measuring electrode (122), and the impedance can be calculated using the value. Using the impedance calculation result, the body composition of the animal, such as body fat mass, extracellular water, and intracellular water, can be analyzed based on various estimation formulas established through various studies.

[0102] The above body composition analysis unit (400) can calculate preset body composition information such as the animal's body fat mass, muscle mass, and body water level by matching the animal's bio-information, such as animal species, length, circumference, age, and gender, to the subcutaneous fat ratio calculated by the subcutaneous fat analysis unit and the bio-impedance calculated by the impedance measurement unit.

[0103] Accordingly, the body composition analysis unit (400) can calculate total body water (TBW) and extracellular water (ECW) by applying the animal's biological information, the subcutaneous fat ratio, and bioimpedance to a pre-programmed estimation formula.

[0104] In addition, the body composition analysis unit (400) calculates intracellular water (ICW) by subtracting extracellular water (ECW) from total body water (TBW), and fat-free mass (FFM) can be calculated by dividing total body water (TBW) by a water coefficient of 0.732. In addition, body fat mass (FM) can be calculated by subtracting fat-free mass (FFM) from body weight (BW).

[0105] In addition, the body composition analysis unit (400) can generate a body mass index (PMI: Pet Mass Index) of an animal by indexing the value calculated as the ratio of lean body mass and body fat mass (FFM / FM) using a pre-generated reference value table.

[0106] In this way, calculating each body composition information using the animal's biological information and the above-mentioned subcutaneous fat ratio and bioimpedance based on various estimation formulas is widely used in general body composition analysis devices. Therefore, the body composition analysis unit is not limited to a specific estimation formula and can, of course, calculate the animal's body fat mass, muscle mass, body water level, etc. in detail using this.

[0107] In addition, the animal body composition analysis device (10) according to the present invention may further include a display unit (500) that allows the measurer to visually check various body composition information of the animal calculated by the body composition analysis unit on site, as illustrated in FIG. 1.

[0108] The above display unit (500) is installed on the other side of the housing where the dual sensor unit is installed, and can display the subcutaneous fat ratio calculated from the subcutaneous fat analysis unit and the bioimpedance calculated from the impedance measurement unit together with the body composition information calculated from the body composition analysis unit so that the user can check them while measuring.

[0109] In addition, the animal body composition analysis device (10) according to the present invention may further include a communication unit (600) that can transmit the body composition information calculated by the body composition analysis unit to a pre-matched smart phone of a measurer or a remote server through a wireless communication network.

[0110] In this way, by transmitting and storing the body composition information, subcutaneous fat ratio, and bio-impedance to the measurer's smartphone or server through the communication unit (600), it is possible to continuously monitor changes in the body composition of a specific animal, which can be utilized for animal care.

[0111]

[0112] Next, with reference to FIG. 9, a body composition analysis method for animals according to another embodiment of the present invention will be described.

[0113] Figure 9 is a flow chart of a body composition analysis method for animals according to the present invention.

[0114] Referring to FIG. 9, a body composition analysis method for an animal according to another embodiment of the present invention may include a step (S100) of determining a wavelength and light quantity of near-infrared rays to be irradiated to the skin tissue of an animal, controlling the irradiation of near-infrared rays from a first light source and a second light source with a predetermined time difference, and calculating a subcutaneous fat ratio of the animal using the ratio of the absorption rate of the second light source to the absorption rate of the first light source based on the amount of light detected by a photodetector; a step (S200) of generating an alternating current having a predetermined frequency and then controlling the application of the alternating current to the skin tissue of the animal from a constant current electrode, and calculating a bioimpedance of the animal by measuring a voltage dropped while reacting with the skin tissue at a measurement electrode; and a step (S300) of analyzing and providing a body composition including body fat mass, muscle mass, and body water content of an animal as a measurement target by matching the bioinformation of the animal to the subcutaneous fat mass and bioimpedance.

[0115] In the step (S100) of calculating the subcutaneous fat ratio of the above animal, first, a near-infrared ray having a center wavelength of 900 to 940 nm is irradiated from a first light source, and based on the amount of near-infrared ray irradiated from the first light source and reflected from skin tissue and received by the photodetector, a look-up table prepared in advance is used to set the amount of light of the first light source, which serves as a reference value.

[0116] At this time, since the central wavelength of the near-infrared light irradiated from the first light source has already been determined, the light quantity of the first light source can be determined using the lookup table. That is, if the light quantity of the first light source received by the photodetector is insufficient, the reference value of the first light source can be set using the lookup table so that the light quantity of the first light source increases.

[0117] Thereafter, the light quantity of the second light source corresponding to the light quantity of the first light source set as the reference value is determined using the lookup table, and the light quantity of the second light source is controlled to have the set value using a converter (DAC), so that near-infrared rays with a center wavelength of 940 to 1040 nm from the second light source are irradiated with the light quantity of the set value and applied to the skin tissue of the animal.

[0118] And, the amount of near-infrared light reflected from the skin tissue after being irradiated by the second light source and received by the photodetector can be measured.

[0119] In addition, in the step (S100) of calculating the subcutaneous fat ratio of the animal, the subcutaneous fat ratio can be calculated based on the ratio of the absorption rate of the first light source absorbed in the skin tissue and the absorption rate of the second light source absorbed in the skin tissue.

[0120] In the step (S200) of calculating the bioimpedance of the animal, an alternating current having a certain frequency is generated and then applied to the skin tissue of the animal from a constant current electrode, and the voltage dropped while reacting with the skin tissue can be measured from a measurement electrode.

[0121] At this time, in the step (S200) of calculating the bioimpedance of the animal, an AC constant current having at least three frequencies centered on 50 KHz is sequentially generated to enable calculation of impedance by multiple frequencies, and is applied to the constant current electrode, and each AC constant current having a different frequency can be measured by the measurement electrode.

[0122] Thereafter, in the step (S200) of calculating the bioimpedance of the animal, the phase difference, which is the difference between the voltage phase and the current phase, is detected using the voltage measured at the measuring electrode in response to each of the alternating currents having different frequencies applied to the constant current electrode, and the impedance of the animal can be calculated based on the detected phase difference.

[0123] At this time, since alternating currents with different frequencies are applied multiple times and the phase difference is detected for each, the phase difference to be applied to calculate the animal's bioimpedance must be determined.

[0124] Accordingly, in the step (S200) of calculating the bioimpedance of the animal, the arithmetic mean of the phase differences detected for each alternating current can be determined as the phase difference to be applied to calculate the bioimpedance.

[0125] In addition, in the step (S200) of calculating the bioimpedance of the animal, the allowable range of phase differences that can be detected is set in advance, and if the detected phase difference for each alternating current is out of the allowable range, it is judged that there is an error in the measurement and is deleted, and only the phase differences within the allowable range are selected as valid values, and then the arithmetic average of the selected phase differences can be determined as the phase difference to be applied to calculate the bioimpedance.

[0126] In addition, in the step (S200) of calculating the bioimpedance of the animal, an arbitrary reference phase difference that can be detected from the measurement subjects is set, and if the detected phase difference is a value close to the reference phase difference, a higher weight is given to it than a value that is not, and the arithmetic mean of the phase differences to which the weights are reflected can be determined as the phase difference to be applied in calculating the bioimpedance.

[0127] At this time, the reference phase difference can be set to the phase difference detected in the most recent measurement of the animal in question, or can be set to the average of phase differences measured in other animals with the same biological information.

[0128] In the step (S300) of analyzing and providing the above body composition, the subcutaneous fat ratio and bioimpedance are matched with the biological information of the animal being measured, such as animal species, length, circumference, age, and sex, and then preset body composition information, such as the animal's body fat mass, muscle mass, and body water content, can be calculated.

[0129] To this end, the total body water (TBW) and extracellular water (ECW) can be calculated by applying the animal's biological information, the subcutaneous fat ratio, and bioimpedance to a pre-programmed estimation formula.

[0130] In addition, in the step (S300) of analyzing and providing the above body composition, intracellular water (ICW) is calculated by subtracting extracellular water (ECW) from total body water (TBW), and fat-free mass (FFM) can be calculated by dividing total body water (TBW) by the water coefficient of 0.732. In addition, body fat mass (FM) can be calculated by subtracting fat-free mass (FFM) from body weight (BW).

[0131] In addition, the value calculated as the ratio of lean body mass to body fat mass (FFM / FM) can be indexed using a pre-created reference value table, and then generated as the animal body mass index (PMI: Pet Mass Index).

[0132] Additionally, in the step (S300) of analyzing and providing the body composition, the calculated body composition information can be displayed via a display device, allowing the person measuring the body composition to check it in real time. Furthermore, the calculated body composition information can be transmitted to a pre-configured smartphone or server via a communication network for cumulative storage, thereby enabling continuous monitoring of changes in the animal's body composition and utilization in animal care.

[0133] The above detailed description should not be construed as limiting in any respect and should be considered illustrative only. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are intended to be included within the scope of the present invention.

Claims

1. A dual sensor unit in which a near-infrared sensor that irradiates near-infrared rays to the animal's skin and a constant current electrode that applies alternating current to the animal's skin are exposed together on one side of the housing so that they can come into contact with the skin of the animal being measured; A subcutaneous fat analysis unit that detects the amount of near-infrared light reflected within skin tissue after being irradiated onto the animal's skin from the above near-infrared sensor and calculates the subcutaneous fat ratio; An impedance measuring unit that calculates bioimpedance by using the current received from the measuring electrode after being applied to the animal's skin from the above-mentioned constant current electrode; and A body composition analysis device for animals, comprising a body composition analysis unit that analyzes and provides body composition, including body fat mass, muscle mass, and body water content, of an animal as a measurement target by matching the animal's bio-information to the above-mentioned subcutaneous fat ratio and bio-impedance.

2. In paragraph 1, The above dual sensor part, A near-infrared sensor installed in the inner space of a plate-shaped plate and irradiating near-infrared rays of a preset wavelength; and It includes an impedance sensing unit installed on the outer periphery of the near-infrared sensor and applying an alternating current having a preset frequency; The above near-infrared sensor, An animal body composition analysis device comprising a first light source that irradiates near-infrared light with a center wavelength of 900 to 940 nm, a second light source that irradiates near-infrared light with a center wavelength of 940 to 1040 nm, and a photodetector that receives light reflected from inside skin tissue after being irradiated onto the skin of the animal from the first light source or the second light source.

3. In paragraph 2, The above near-infrared sensor, A shielding wall that blocks the movement of light between the first and second light sources and the photodetector; and An animal body composition analysis device further comprising a transparent window covering the upper portion of a near-infrared sensor in which the first light source, the second light source, and the photodetector are arranged.

4. In paragraph 2, The above impedance sensing unit, A constant current electrode that contacts the animal's skin and applies an alternating current having a constant frequency to the animal's skin; and A measuring electrode for measuring the voltage dropped as the alternating current passes through the animal's skin; An animal body composition analysis device, wherein the above-mentioned constant current electrode and the measuring electrode are formed as pin-shaped electrodes protruding outward higher than the upper end of the near-infrared sensor on a plate-shaped plate.

5. In paragraph 2, The above impedance sensing unit, An animal body composition analysis device, wherein at least one constant current electrode and one or more measuring electrodes are arranged symmetrically around the outer periphery of the near-infrared sensor, each forming a group.

6. In paragraph 2, The above impedance sensing unit, An animal body composition analysis device, wherein one constant current electrode and one measuring electrode form a pair of electrode groups, and at least one pair of electrode groups is arranged at equal intervals around the near-infrared sensor.

7. In paragraph 2, The above subcutaneous fat analysis section, A light source control unit that determines the wavelength and amount of near-infrared light to be irradiated to the skin tissue of the animal and controls the near-infrared light to be irradiated from the first light source and the second light source at a constant time interval; and An animal body composition analysis device, comprising: a light quantity analysis unit that calculates the ratio of the absorption rate of a second light source to the absorption rate of a first light source based on the amount of light detected by the above-mentioned photodetector, and then calculates the subcutaneous fat ratio of the animal based on the ratio of the calculated absorption rates.

8. In paragraph 2, The above light source control unit, An animal body composition analysis device, which controls a first light source to irradiate near-infrared rays having a center wavelength of 900 to 940 nm, sets the light quantity of the first light source as a reference value on a lookup table provided in advance based on the light quantity of the near-infrared rays irradiated from the first light source and received by the photodetector, determines the light quantity of the second light source corresponding to the light quantity of the first light source as the reference value using the lookup table, and then controls the second light source to irradiate near-infrared rays.

9. In paragraph 2, The above impedance measuring unit, A constant current output control unit that generates an alternating current having a certain frequency and then controls the application of the constant current to the animal's skin tissue from the constant current electrode, and measures the voltage dropped while reacting with the skin tissue from the measurement electrode; and An animal body composition analysis device, comprising an impedance calculation unit that detects a voltage phase and a current phase by comparing a voltage value measured from the above-mentioned measuring electrode with an AC constant current value applied from the above-mentioned constant current electrode, detects a phase difference based on the voltage phase and the current phase, and then calculates the animal's bioimpedance using the detected phase difference.

10. In paragraph 9, The above constant current output control unit, An animal body composition analysis device that sequentially generates alternating currents having at least three different frequencies centered on 50 KHz and applies them to the constant current electrodes so that a multi-frequency measurement method can be applied, and controls the measurement of voltage values ​​measured at the measurement electrodes in response to each alternating current having a different frequency.

11. In paragraph 1, An animal body composition analysis device further comprising a display unit that displays the animal body composition information calculated from the body composition analysis unit so that the information can be visually confirmed.

12. In paragraph 1, An animal body composition analysis device further comprising a communication unit that transmits the animal body composition information calculated from the body composition analysis unit to a pre-matched smartphone or server via a wireless communication network.

13. A step of determining the wavelength and amount of near-infrared light to be irradiated to the skin tissue of an animal, controlling the irradiation of near-infrared light from a first light source and a second light source at a constant time interval, and calculating the subcutaneous fat ratio of the animal by using the ratio of the absorption rate of the second light source to the absorption rate of the first light source based on the amount of light detected by the photodetector; A step of generating an alternating current having a certain frequency, controlling it to be applied to the skin tissue of an animal from a constant current electrode, and measuring the voltage dropped while reacting with the skin tissue at a measuring electrode to calculate the bioimpedance of the animal; and A method for analyzing body composition of an animal, comprising: a step of analyzing and providing body composition including body fat mass, muscle mass, and body water content of the animal as a measurement target by matching the animal's bio-information to the above-mentioned subcutaneous fat ratio and bio-impedance.

14. In paragraph 13, In the step of calculating the subcutaneous fat ratio of the above animal, A method for analyzing body composition of an animal, comprising: irradiating a near-infrared ray having a center wavelength of 900 to 940 nm from a first light source; setting the light quantity of the first light source as a reference value using a look-up table prepared in advance based on the light quantity of the near-infrared ray received by the photodetector after being irradiated from the first light source; determining the light quantity of a second light source corresponding to the light quantity of the first light source as a reference value using the look-up table; and then irradiating a near-infrared ray having a center wavelength of 940 to 1040 nm from the second light source.

15. In paragraph 13, In the step of calculating the bioimpedance of the above animal, A method for analyzing body composition of an animal, which sequentially generates an alternating current having at least three frequencies centered on 50 KHz, applies it to a constant current electrode, and measures the voltage value measured at a measuring electrode corresponding to each alternating current having a different frequency.

16. In paragraph 13, In the step of calculating the bioimpedance of the above animal, A method for analyzing body composition of an animal, wherein the phase difference between the voltage phase and the current phase is detected using the voltage measured at the measuring electrode for each of a plurality of alternating currents applied from the constant current electrode, and then the arithmetic average of the detected phase differences is determined as the phase difference to be applied to calculate bioimpedance.

17. In paragraph 13, In the step of calculating the bioimpedance of the above animal, A method for analyzing body composition of an animal, wherein the phase difference between the voltage phase and the current phase is detected using the voltage measured at the measuring electrode for each of a plurality of alternating currents applied from the constant current electrode, the allowable range of phase differences that can be detected when applying the alternating current is set in advance, only the phase differences within the allowable range are selected as valid values, and the arithmetic average of the selected phase differences is determined as the phase difference to be applied to calculate bioimpedance.

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