WO2008092302A1

WO2008092302A1 - Body composition analyzing apparatus and method for measuring body resistance by using frequencies

Info

Publication number: WO2008092302A1
Application number: PCT/CN2007/000313
Authority: WO
Inventors: Oi Shan Lau
Original assignee: Channel Way Holdings Co., Ltd
Priority date: 2007-01-29
Filing date: 2007-01-29
Publication date: 2008-08-07

Abstract

A body composition analyzing apparatus or method for measuring the body resistance by using frequencies, solves the technical problem of analyzing and measuring weight, fat ratio, water content, muscle content and bone mineral content. The analyzing apparatus comprises a scale pan (2), weight sensors (9) connected with the scale pan (2), a LCD (16A) and a printed circuit board (PCBA) connected therewith, conductive electrodes (2A,2B,3A,3B), a keyboard circuit (14A), a memory circuit (15A), a wirelessly transmitting circuit (17A) and a USB circuit (18A). The measuring method is divided into two periods for measuring the body resistance signaland the reference resistance respectively, employing a microprogrammed control unit (MCU) to calculate body fat ratio, water ratio, bone mineral content, metabolism, and heat amount necessary to be incepted.

Description

Human body component analyzer and measuring method for spectrum measuring human body resistance

TECHNICAL FIELD The present invention relates to a body composition analyzer for measuring body resistance of a human body, in particular, a human body weight, a body fat percentage, a body body moisture content, a human body muscle content, a human bone mineral content, and a human body day. The required heat measurement function is indeed

Human body comprehensive test equipment.

Recognize

Background technique '

Ben

The weight of the human body and the body fat percentage are important for evaluating the degree of obesity, nutritional status and health of the human body. At the same time, the water content of the human body, the muscle content of the human body, and the mineral content of the human bones are important for the health of the human body. So far, there are many methods for measuring the body weight, body fat, moisture and other components, such as: weighing the human body with a human scale, measuring the fat percentage of the body fat, calculating the height and weight, ultrasonic measurement, isotope measurement Method, underwater weighing method, skin wrinkle method and infrared measurement method, etc. There are also some methods for measuring the moisture content of the human body. For example, commonly used measurement methods are drug dilution method, capacitive gate capacitance sensor measurement, and the like. There are also methods for measuring the muscle content of the human body, such as magnet resonance imaging MRI, computed tomography CT, dual energy X-ray absorptiometry DEXA, and the like. Many of the above-mentioned widely used methods have their own shortcomings. They are either simple or inaccurate, or the technology is complicated and costly, and the operation is troublesome. Many measurements must be completed in the hospital. SUMMARY OF THE INVENTION An object of the present invention is to provide a body composition analyzer for measuring body resistance of a spectrum and The measurement method, the technical problem to be solved, is to be able to easily and scientifically and accurately perform analysis and measurement of body weight, body fat percentage, body body moisture content, human body muscle content and human bone mineral content.

The invention adopts the following technical solutions: a body composition analyzer for measuring human body resistance, the analyzer is used for measuring body weight, body fat percentage, moisture rate, muscle rate, human bone mineral content, and calculating human body day The metabolism and the energy required for human biological activities, identify the user, and pass the measured data to other external and internal devices, including:

Weighing scale weighing pan, 4 weighing sensors connected to the weighing pan;

a liquid crystal display for displaying human body weight and human body moisture, fat, muscle, bone mineral components and a printed circuit board connected thereto;

4 conductive electrodes for the measurement of human bioelectrical resistance;

a keyboard circuit for inputting personal data by a user;

Memory circuit

Wireless transmission circuit

USB circuit.

The printed wiring board of the present invention comprises:

An 8-bit microcontroller;

One of the input/output terminals of the 8-bit microcontroller is connected to the waveform conversion and the input of the constant current source circuit;

The output of the waveform conversion and constant current source circuit of the present invention is connected to one conductive electrode sheet;

The printed circuit board of the invention has two follower circuits, and the input ends thereof are respectively electrically connected The pole piece and the one end of the selector switch are connected;

The output of the follower circuit of the present invention is respectively connected to the input end of the operational amplifier; 'the output end of the operational amplifier of the present invention is connected to the input end of the filter circuit; the output end of the filter circuit of the present invention and the rectifier The input ends of the circuit are connected; the output of the rectifier circuit of the present invention is connected to the input of another filter circuit;

The output of the other filter circuit of the present invention is connected to one end of an 8-bit microcontroller, and the other filter circuit outputs a signal to a selection circuit inside the 8-bit microcontroller.

The input terminals of the selection circuit of the 8-bit microcontroller of the present invention are respectively connected to the output end of the load cell and the output end of the other filter circuit;

The 8-bit microcontroller of the present invention, wherein an input/output terminal is connected to the input of the waveform conversion and constant current source circuit, and outputs a square wave signal of a plurality of frequencies to the input end of the waveform conversion and constant current source circuit;

The square wave signal of multiple frequencies output by the 8-bit microcontroller of the present invention is a square wave of three sets of frequencies, the first group is a group of square wave signals with a center frequency of 17KHZ, and the second group is 54KHZ. a set of square wave signals with a center frequency, and a third group of square wave signals with a center frequency of 100 kHz;

The square wave of the three sets of frequencies described in the present invention has a duty ratio of 1:1.

The four conductive electrodes provided on the weighing pan of the invention are divided into two groups of left and right, two pieces in each group, which are respectively in contact with the left and right feet, and each component is a front electrode piece and a rear electrode piece, which respectively correspond to the tester's sole In contact with the heel;

The electrode piece in contact with the left foot of the present invention, respectively, and the waveform conversion and constant current source The output end of the circuit, the input end of the follower is connected to one end of the other selection switch; the electrode piece in contact with the left heel of the present invention is respectively connected to one end of the other selection switch and one end of the digital adjustable potentiometer connection;

The other end of the digital adjustable potentiometer of the present invention is connected to one end of the selection switch; the electrode piece in contact with the right foot of the present invention and the electrode piece in contact with the right heel are connected to one end of the selection switch;

The electrode material of the electrode sheet of the present invention is an electroplated conductive coating material.

The keys of the keyboard circuit of the present invention are three keyboards, which are setting, up, and down keys respectively; the setting keys of the present invention are used to set the start and end of the user and the data confirmation input selected by the user to the microcontroller and In the memory circuit, the up and down keys are used to select personal data of the user;

The keyboard of the present invention is used for selecting a user number of a user, and inputting the gender, age, height and daily physical activity level of the user;

The daily physical activity level of the user of the present invention is divided into five exercise levels. A method for measuring a body fat rate by a spectrum, wherein the measurement is divided into two time periods, the first time period is to measure the human body resistance signal, and the second time period is to measure the reference resistance; the first time period includes the following steps: A square wave signal of not less than 3 frequencies is outputted from one input/output terminal of the 8-bit microcontroller, and the square wave signal is a group of square wave signals with a center frequency of 54 kHz, and the square wave signal is subjected to waveform conversion and constant The flow source circuit is transformed into a set of sinusoidal crossover signals of corresponding frequencies. The sinusoidal crossover signal enters the human body through two electrodes contacting the left and left heels of the human body, and then enters the 'electrode through two electrodes contacting the right and the right heels. The circuit, after 2 levels of amplification, 2 stages of filtering, the digital signal of the human body resistance after analog-to-digital conversion by the analog-to-digital converter of the microcontroller is input to the 8-bit microcontroller core; The time period includes the following steps: the signal output from the digital potentiometer is sent to the detection circuit, and the digital signal of the digital potentiometer after analog-to-digital conversion is input to the detection circuit through the 2-stage amplification and the 2-stage filtering. The 8-bit microcontroller core; the 8-bit microcontroller calculates the body resistance based on the human body resistance signal and the potentiometer reference signal, and calculates the body fat percentage based on the body resistance and the pre-entered tester's personal biological information.

A method for measuring a human body moisture rate, a human muscle rate, and a human bone mineral content, wherein the measurement is divided into two time periods, the first time period is a measurement of a human body resistance signal, and the second time period is The reference resistor is measured; the first period includes the following steps: one set of input/output terminals of the 8-bit microcontroller outputs two sets of square wave signals of a plurality of small three frequencies, respectively, and measures a group of human body moisture rates. The square wave signal of frequency is a square wave signal measuring a human body muscle rate and a human bone mineral content with a square wave signal with a center frequency of 17KHZ. It is a square wave signal with a center frequency of 100KHZ, a square wave signal. After the waveform conversion and the constant current source circuit are converted into a set of sinusoidal crossover signals of corresponding frequencies, the sinusoidal crossover signal enters the human body through two electrodes contacting the left and left heels of the human body, and then contacts the right and the right heels. The electrodes enter the detection circuit, and are subjected to 2-stage amplification and 2-stage filtering, and the human body resistance after analog-to-digital conversion is performed by an analog-to-digital converter in the microcontroller. The digital signal is input to the 8-bit microcontroller core; the second period includes the following steps: The digital potentiometer outputs the signal to the detection circuit, which is amplified by 2 stages, filtered by 2 stages, and passed through the analog-to-digital converter in the microcontroller. The potentiometer reference digital signal after analog-to-digital conversion is input to the 8-bit microcontroller core; the 8-bit microcontroller calculates the human body resistance according to the human body resistance signal and the digital potentiometer reference signal, according to the human body resistance and the pre-input test The personal biometric information calculates the human body's moisture rate, human muscle rate, and human bone mineral content.

A measure of the body's daily metabolism and the amount of calories needed for human biological activity The value method includes the following steps: The tester inputs his physical activity intensity category, gender, height and age data through the keyboard, the physical activity intensity category is divided into 5 exercise levels, and the weight signal sensed by the load cell Passed to an 8-bit microcontroller, an 8-bit microcontroller that calculates the calorie value of the tester's daily metabolism and human biological activity. '

Compared with the prior art, the invention measures the human body resistance by spectrum to measure the body weight, the body fat percentage, the body body moisture content, the human body muscle content, the human bone mineral content, the analyzer cost is low, the operation Easy to use, accurate measurement, convenient for users to understand their health and nutritional status, combined with the tester's daily physical activity intensity level, weight and the data of the individual organisms input by the measurer, calculate the daily calorie intake of the tester. Value, when the user makes the second measurement, the analyzer can automatically identify the tester, give the tester's user number and personal data, and transfer the tester's data to the external device when needed for analysis and research. Use, suitable for measurement analysis of the family.

DRAWINGS

1 is a circuit schematic diagram of an embodiment of the present invention.

Figure 2 is a frequency response diagram of human tissue.

Figure 3 is a three-element equivalent circuit model of human tissue.

Figure 4 is a schematic illustration of the test of the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. As shown in FIG. 4, the body composition analyzer for measuring the body resistance of the present invention comprises a weighing pan 2 for weighing the body, and the glass weighing pan 2 is provided with four conductive electrodes, which are directly connected to the left and right feet of the human body. Touch, the four electrodes are divided into two groups, two in each group, which are the front electrode piece and the back electrode piece, which are respectively in contact with the tester's sole and the heel, and the electrode material is a conductive coating material coated on the glass, respectively The front electrode piece 2A and the rear electrode piece 2B of the left foot, and the front electrode piece 3A and the rear electrode piece 3B of the right foot are respectively in contact with the tester's sole and the heel, and the AC test signal is entered from the left foot to be tested. In the human body, the AC test signal is attenuated by the human body, outputted from the body to be tested via the right foot, and enters the input end of the follower circuit 4. There are also four weight sensors 9 connected to the glass weighing pan 2.

As shown in FIG. 1, the body component analyzer of the spectrum measuring body resistance of the present invention has a printed circuit board PCBA, and an 8-bit microcontroller MCU is disposed on the PCBA, and input terminals of the selection circuit 10A in the MCU are respectively connected with the load cell 9A. The output terminal is connected to the output terminal of the filter circuit 8A.

One of the input/output terminals of the MCU is connected to the waveform conversion and the input terminal of the constant current source circuit 1A, and the frequency square wave signal output by the MCU is applied to the waveform conversion and the input terminal of the constant current source circuit 1A, and the square wave signal is three sets of frequencies. Square wave, square wave signal of not less than three frequencies in each group, the first group of square wave signals with center frequency of 17KHZ, and the second group of square wave signals with center frequency of 54KHZ, group III A group of square wave signals with a center frequency of 100 kHz, the square wave duty ratio of the three groups of frequencies is 1:1.

The output of the mode conversion and constant current source circuit 1A is connected to the conductive electrode sheet 2A, and the electrode sheet 2A in contact with the left foot is also connected to the input end of the follower 4A and one end of the other selection switch 1B, respectively. The electrode pads 2B contacting the heel are respectively connected to one end of the other selection switch 1B and one end of the digital adjustable potentiometer 1, and the other end of the digital adjustable potentiometer is connected to one end of the selection switch 1C; The electrode sheet 3A is connected to the electrode sheet 3C in contact with the right heel and one end of the selection switch 1C. Wave type conversion and constant current source The road 1A outputs an AC test signal to the tested human body, and the two follower circuits 4A and B have their input terminals connected to the electrode pads 2A and the one end of the selection switch 1C, respectively, and the output terminals thereof are respectively connected to the input terminals of the operational amplifier 5A. . The signal output from the operational amplifier 5A is passed through the filter circuit 6A, the rectifier circuit 7A, the filter circuit 8A to the input terminal of the MCU selection circuit 10A, and then amplified by the amplifier 11A of the MCU, and the 16-bit analog-to-digital converter ADC in the MCU. The 12A is converted to a number from which the value of the body impedance is calculated from the reference value in the CORE of the MCU core.

The output of the MCU is also connected to the liquid crystal display LCD 16A, the keyboard 14A, the memory 15A, the wireless transmission circuit 17A, and the USB interface 18A, respectively. The keyboard is a three-button keyboard, which is set to SET, UP up, and down to DO. The SET button is used to set the start and end of the user, and the data selected by the user is confirmed to be input into the MCU and the memory. The DOWN key is used to select the user's personal data, such as gender: male, female, male athlete, female athlete, age, height, daily physical activity level, daily physical activity level, divided into five sports levels to choose from.

As a preferred embodiment, the digital adjustable potentiometer of the present invention is CAT5113, the MCU adopts SP8P1909, the selection circuit adopts CD4053, the waveform conversion and constant current source circuit adopts Unicom Holding Co., Ltd. HD-3 module, and the follower adopts SGM324. The operational amplifier uses SGM324, the two filter circuits use RC filter, the rectifier circuit uses 1N60, the weight sensor uses resistive pressure sensor, the keyboard uses the shrapnel switch button, the memory uses AT24C02, the display uses liquid crystal display, and the transmission frequency of wireless transmission circuit For 433MHZ, the bit A/D converter uses a 16-bit ∑Δ analog-to-digital converter, the core of the microcontroller uses SN8P1909, the select switch 1C uses CD4053, and the other select switch 1B uses CD4053.

The body composition analyzer of the spectrum measuring human body resistance of the present invention has the following functions: measurement Body weight, body fat percentage, body water rate, body muscle rate, human bone mineral content, analysis and calculation of the body's daily metabolism and human body biological activities

'Quantity, at the same time, can automatically identify the user, pass the measured data to other external devices and internal devices through the wireless transmission circuit or USB interface.

The working process of the human body component test analyzer of the invention is: the tester first inputs the biological characteristic information of the gender, the height, the age, the physical activity intensity and the like through the keyboard, and the output of the MCU outputs the three sets of frequency square wave signals, wherein A group of square wave signals measuring the body fat rate is not less than three square wave signals with a center frequency of 54 kHz, and a square wave signal of a set of frequencies for measuring the body moisture rate is not less than three, at 17 kHz. As a square wave signal of the center frequency, a square wave signal of a set of frequencies measuring human muscle rate and human bone mineral content is not less than three square wave signals with a center frequency of 100 kHz. The square wave signal is converted into a sinusoidal crossover signal of the corresponding frequency through the waveform conversion and constant current source circuit, and the sinusoidal crossover signal enters the human body through the two electrodes contacting the left foot and the left heel of the test subject, and passes through the right foot after passing through the human body. The two electrodes of the right heel are input to the detection circuit, and the signals are amplified by the 2-stage amplification and the 2-stage filtering, and then converted to the MCU core of the 8-bit microcontroller to calculate the human body resistance; the digital potentiometer output The signal to the detection circuit is subjected to 2-stage amplification and 2-stage filtering, and the potentiometer reference signal after analog-to-digital conversion is input to the MCU core of the 8-bit microcontroller; the 8-bit microcontroller MCU is based on the human body resistance signal and the digital potentiometer The reference signal is used to calculate the body resistance, and the body fat percentage, the body water rate, the human muscle rate, and the human bone mineral content are calculated based on the body resistance and the pre-entered tester's personal biological information. The calorie value of the subject's daily metabolism and human biological activity is calculated by combining the sex, height, age, physical activity intensity, and body weight of the test subject, and is displayed on the display. In the test process of body fat percentage, human moisture rate, human muscle rate and human bone mineral content, the present invention uses three frequency segment test signals to separately measure human body resistance, in the measurement process of each human body component. In the middle, it is divided into two stages, for example, in the measurement of body fat percentage, the first stage: as shown in Fig. 1, one input/output terminal of the microprocessor circuit 20A outputs a plurality of sets of center frequencies of 54 kHz. The test signal of the square wave of the frequency, the duty ratio of the square wave signal is 1: 1, the square wave signal is output to the input end of the waveform conversion and constant current source circuit 1A, after the waveform conversion and the constant current source circuit 1A, the The signal becomes a constant current crossover signal, the switch 1B is closed, the electrode sheets 2A and 2B are turned on, and the switch 1C is turned on at the E terminal, and the signal enters the human body through the left foot electrode sheets 2A and 2B, and enters the electrode on the right foot of the human body. Pieces 3A and 3B, due to the capacitive impedance of the human body, the amplitude of the AC sine wave signal will be attenuated to some extent, and the phase of the voltage will also be shifted to some extent. After the measurement signal of the human body passes through the followers 4A, 4B, it is amplified by the amplifier 5A in turn, the filter 6A filters out the clutter, the waveform shaper 7A is shaped, the filter 8A filters out the clutter again, and finally the selector of the microprocessor 20A After 10A and amplifier 11A enter the 16-bit A/D conversion of microprocessor 20A, an A/D1 value is obtained.

A/D1=K (R+2R1) (1)

K is a constant, which can be calculated according to the parameters of the circuit. R is the body resistance, and R1 is the contact resistance of the human foot or the heel and the electrode piece.

In the second stage, the switch 1B is open, and the switch 1C is turned on, so that the measurement signal of the digital potentiometer 1D enters the detection circuit, and finally the 16-bit A/D converter of the microprocessor 20A obtains another A/D2 value. . Adjust the digital potentiometer 1D so that the value of the body resistance can be calculated.

A/D2=K (R0+2R1) (2) RO is known, if R0 = 200 ohms, use (1) minus (2) to get:

R= (A/Dl-A/D2) /K+200 (3)

Thereby, the value of the human body resistance is obtained, and the measuring method of the human body resistance of the present invention can reduce the error caused by the contact resistance of the human foot or the heel and the electrode piece, and improve the measurement accuracy.

The present invention uses a plurality of frequency spectral signals to measure body resistance, which eliminates measurement errors caused by accidental factors.

The square wave test signal output by the MCU becomes a constant current crossover signal after the waveform conversion and constant current source circuit. After the signal enters the human body, the AC sinusoidal signal is due to the capacitive impedance of the human body. The amplitude will have a certain degree of attenuation, and the phase of the voltage will also be offset to some extent. Tested: The different tissues of the human body have different degrees of electrical signals to the same frequency. The low-density tissues of the human body, such as human blood and human secretions, have a low degree of blockage of electrical signals. The phase shift of the electrical signal voltage is small; the high-density tissue of the human body, such as human body fat, human muscles, human bones, and minerals in human bones, have a large degree of blockage of electrical signals, and the electrical signal voltage The phase offset is also large. At the same time, the different density of the human body has different degrees of blockade for the electrical signals of different frequencies. In general, high-density human tissue has a high degree of blockage of high-frequency AC signals, and its phase shift of voltage is also large. Low-density human tissue, the degree of blockade of low-frequency AC signals is relatively high-frequency communication. The degree of signal block is large, and the phase shift of the voltage is also large, so the organization of each part of the human body is different in damping of electrical signals of different frequencies.

Impedance characteristics of human tissue: The most basic functional unit of the human body is cells. The cells are surrounded by a semi-permeable membrane with a special structure and function. We call it a cell membrane that allows certain substances to pass selectively while maintaining the intracellular composition of the substance. Stable. The cell membrane is not only a barrier between the cell and the surrounding environment, but also a gateway for cells to receive external signals. Various physical stimuli in the cellular environment, chemical stimuli such as hormones produced in the human body, human biological signals of the nervous system or external electrical signals, etc., many of which are first acting on the cell membrane and then acting on the cytoplasm of the cells. And the nucleus. The human cells are bathed in a conductive extracellular fluid containing conductive liquid intracellular fluid. The electrical properties of extracellular fluids and intracellular fluids are close to electrical resistance, while cell membranes are equivalent to capacitance. Therefore, the equivalent circuit of human tissue should be a series-parallel network composed of several resistors and capacitors.

As shown in Fig. 3, in the three-component equivalent circuit model of human tissue, Re is the extracellular fluid resistance, Ri is the intracellular liquid resistance, and Zc is the cell membrane capacitance tolerance. The body tissue impedance Z can be expressed by the following expression:

Z II Re (Zc+Ri ) I (Re+Zc+Ri) (4)

Where Zc II 1/WC is the capacitive reactance of the cell membrane, W is the frequency of the test signal, and C is the capacitance of the cell membrane. It can be seen from equation (4) that the measured electrical signals of different frequencies have different body impedances Z, which vary with the frequency of the test signals. Since the human body has various tissues, the electrical conductivity of each tissue is different. For measuring electrical signals entering a blood vessel, since Re is much smaller than (Zc + Ri), the electrical signal entering the blood is mainly conducted by the extracellular fluid. For example, a vessel with a resistivity of P, a length of L, and a cross section of A, with a resistance value of:

R two p L/A (5)

Multiplying the numerator and denominator on the right side of equation (5) by L gives:

R=p L*I7(L*A) (6)

L*A=V, V is the volume of blood in the blood vessels, available: V two p L*L/R (7)

It can be obtained from (7), the blood content of the human body has a certain mathematical relationship with the resistance value. For other tissues of the human body, it is difficult to establish a mathematical model due to the existence of cell membrane capacitance, so the measurement of the content of human tissue, The work of the inventive body composition test analyzer is based on the dual basis of bioelectrical impedance analysis BIA and statistics, so the tester's personal biological data needs to be input during the measurement.

It can be seen from (4) that the body impedance Z varies with the frequency of the test signal. When w increases, Zc 2/wc decreases, then Z= Re (Zc+Ri ) I ( Re+Zc+Ri The invention patent uses a set of spectral signals of not less than three frequencies to measure a set of body impedances, 'for example, a set of frequencies using wl, w2, w3...., where wl < w2 < w3 ...... The measured body impedances are Zwl, Zw2, Zw3...., which should satisfy the following relationship:

Zwl>Zw2>Zw3>... (8)

From (8) we can verify the correctness of the human body resistance at a certain frequency and improve the measurement accuracy.

Frequency response of human tissues: The cells of different tissues of the human body vary in shape and size, and the spacing between cells is different. The conductivity of intracellular fluid and extracellular fluid is also different, so different human tissues are different. The frequency of the electrical signal, its frequency response is not the same.

As shown in FIG. 2, which is a frequency response diagram of a certain tissue of the human body, a Q value of a signal attenuation is introduced as a test parameter in the figure, and an AC signal having a current of 5 MA or less is output to the human body tissue, and then the measurement is performed. The trend of changes before and after the AC signal input. The Q value is calculated by:

Q=f * cos ( A Θ ) / (Α1*Α1/Α2*Α2) (9)

f is the frequency of the AC signal, and A1 is the voltage amplitude of the AC constant current source before entering the human body. Value, A2 is the voltage amplitude after passing through the human body, and Δ Θ is the voltage constant change of the AC constant current source and the human body. As can be seen from the figure: As the frequency of the AC signal increases, its Q value is nearly linear before reaching the starting frequency of the characteristic frequency, so dQ/df is approximately constant. When the Q value is at ~f2, f2 is the end frequency of the characteristic frequency, which is expressed as a curve, so dQ/df is not a constant, and dQ/df becomes small. When f2, its Q value is close to a straight line, so dQ/df is approximately constant. It can be concluded from Fig. 2 that the human body tissue has different damping effects for electrical signals of different frequencies, so we choose fl~f2 as the characteristic frequency band for measuring the human tissue. For different races, fl and f2 are slightly different.

Through experiments, the body composition test analyzer of the present invention works between 48KHZ and 60KHZ. As a test frequency band of human body fat, a set of spectral electric signals with a plurality of frequencies having a center frequency of 54 kHz is used as a measure of body fat content. Measurement signal. For human muscle and human bone tissue, the test frequency band of the present invention is 92KHZ to 108KHZ. The present invention uses a plurality of spectral electric signals of a plurality of frequencies having a center frequency of 100 kHz as a measurement signal for measuring the content of human muscle and human bone tissue. The test frequency band of human body water is 12KHZ to 22KHZ, and the present invention uses a plurality of spectral electric signals of a plurality of frequencies having a center frequency of 17 kHz as a measurement signal for measuring the moisture content of the human body. The present invention employs a multi-frequency spectrum test signal to reduce measurement errors.

The body fat percentage was measured, and as described above, the body resistance of the body was measured using a set of measurement signals having a center frequency of 54 kHz. It contains many kinds of human body bio-impedance, and the body fat impedance accounts for 20% to 25% of the whole body's impedance. In the body fat testing process, it is not enough to know only the body fat resistance. The body weight of different body densities varies greatly, such as the body fat resistance and the weight of two people, but their Different body heights have different body fat percentages, so the percentage of body fat has a direct function relationship with the body density of the human body.

The body density of the human body has a certain functional relationship with the height and age of the person. At the same time, the body density of men and women is very different, so the mathematics formula of the following experience is obtained by combining the height, age and sex of the tester: The height, age, and gender are biometric information that is input by a keyboard in advance.

BF (%) = al*Wt- bl*Ht+cl*Age+dl*R+el (ordinary male),

BF (%) = a2*Wt- b2*Ht+c2*Age+d2*R_e2 (ordinary women),

BF (%) two a3*Wt- b3*Ht- c3*Age- d3*R+e3 (male athletes),

BF (%) = a4*Wt- b4*Ht+c4*Age+d4*R+e4 (female athletes),

Where Wt is the weight of the tester, the unit is KG; R is the body impedance, the unit is ohm; Ht is the height of the tester, the unit is cm; Age is the age of the tester. a, b, c, d, e are constants, where:

Al=0. 482, bl2 0 322, cl 2 0. 197, dl=0. 0011, el=32. 098,

A2=0. 618, b2=0. 075, c2=0. 284, d2二 0· 0016, e2=9. 396,

A3=0. 514, b3=0. 503, c3=0. 026, d3二 0· 0010, e3=63. 342,

A4=0. 45, b4=0. 487, c4=0. 072, d4=0. 0012, e4-71. 914,

The invention performs 2-stage filtering on the human body signal, can better filter out the interference signals generated by the human body's heartbeat, breathing, etc., and improve the measurement accuracy.

Measuring human muscles and human bone minerals, using a set of crossover signals with a center frequency of 100KHZ, after passing through the human body, the body impedance can be measured. The human bioimpedance calculated by measuring the human body electrical signal contains many kinds of bio-impedances of human tissue. In fact, human muscle impedance accounts for 35% to 40% of the whole body's impedance, and the human bone's impedance accounts for The entire body impedance is 5% to 8%. Just knowing that human muscle resistance and human bone resistance are not enough, people with different body densities have different muscle content and human bone mineral content, such as human muscle resistance and human bone resistance and the same weight of two people, but he Their height and age are different, their body muscle content and human bone mineral content are not exactly the same, so the human muscle content and human bone mineral content is directly related to the body's body density. The body density of the human body has a certain functional relationship with the height and age of the person. At the same time, the body density of men and women is very different. Therefore, we combine the tester's height, age, and gender to get the following formula:

Human muscle calculation formula:

Muscle (KG) =al*Wt+bl*Ht- cl*Age_dl*R- el (general male),

Muscle (KG) = a2*Wt+b2*Ht- c2*Age+d2*R+e2 (ordinary female),

Muscle (KG) = a3*Wt+b3*Ht- c3*Age- d3*R- e3 (male athlete),

Muscle (KG) = _a 4*Wt+b4*Ht+c4*Age+d4*R-e4 (female athlete).

Where Wt is the weight of the tester, the unit is KG; R is the body impedance, the unit is ohm; Ht is the height of the tester, the unit is cm; Age is the age of the tester. a, b, c, d, e are constants, where: . '

Al=0. 561, bl=0. 191, cl=0. 121, dl=0. 0025, el=12. 751, a2=0. 302, b2=0. 084, c2=0. 037, d2 0. 0013, e2=ll. 747,

A3=0. 739, b3=0. 085, c3 two 0. 062, d3 two 0. 0020, e3=4. 379, a4=0. 474, b4=0. 193, c4=0. 022, d4 two 0. 0015, e4=16. 041 ₀ Human skeleton calculation formula:

Bone (KG) =el*Wt+bl*Ht_cl*A _g e+dl*R- el (ordinary male),

Bone (KG) = e2*Wt+b2*Ht- c2*Age- d2*R+e2 (ordinary female), Bone (KG) =e3*Wt+b3*Ht- c3*Age+d3*R +e3 (male athlete), Bone (KG)

氺Wt+b4*Ht+c4*Age+d4*R - e4 (female athletes).

Where Wt is the weight of the tester, the unit is KG; R is the body impedance, the unit is ohm; Ht is the height of the tester, the unit is cm; Age is the age of the tester. a, b, c, d, e are constants, where

Al=0. 026, bl=0. 011, cl=0. 006, dl=0. 0001, el=0. 556,

A2=0. 016, b2-0. 005, c2=0. 001, d2=0. 0002, e2=0. 541 ,

A3=0. 035, b3=0. 004, c3=0. 003, d3=0. 0002, e3=0. 02,

A4=0. 024, b4=0. 01, c4 two 0. 001, d4 two 0. 0001, e4=0. 766.

To measure the body's moisture content, a set of crossover signals with a center frequency of 17 kHz can be used to measure the value of the body impedance after passing through the human body. People with different body densities have different body water contents, such as two people with the same body impedance and weight, but their height and age are different, their body water content is not exactly the same, the body's body is higher, the body's The larger the volume of the body cavity, the different the body's moisture content. On the other hand, during the growth and development of the human body, the body cavity of the human body is gradually increasing, so the body's water content is also different, and the male and female are also different. Therefore, we combine the tester's height, age, and gender to get the following experience. Calculation formula:

TBW(%) =al*Ht-bl*Wt-cl*Age+dl*R+el (general male),

TBW (%) two a2*Ht-b2*Wt- c2*Age+d2*R+e2 (ordinary female),

TBW (%) = a3*Ht- b3*Wt- c3*Age+d3*R+e3 (male athletes),

TBW (%) -a4*Ht-b4*Wt-c4*Age+d4*R+e4 (female athletes).

Where Wt is the weight of the tester, the unit is KG; R is the body impedance, the unit is ohm; Ht is the height of the tester, the unit is cm; Age is the age of the tester. a, b, c, d, e Is a constant, where

Al=0. 065, bl=0. 377, cl=0. 258, dl=0. 0023, el=82. 617

A2=0. 054, b2=0. 381, c2=0. 253, d2=0. 0016, e2=74. 282

A3=0. 229, b3=0. 332, c3=0. 172, d3=0. 0025, e3=49. 828

A4=0.203, b4=0. 302, c4=0. 133, d4=0. 0020, e4=45. 103 Calculate the body's metabolic heat (calories). By statistical method, we divide the test population into 5 categories, the first category: People who sit still, those who do not or rarely participate in sports, including those who are extremely inactive and sitting all day. The second category: Slightly active people, those who are slightly active, minor activities include: walking, sweeping the floor, playing the piano and cycling (non-competitive). The third category: moderately active people, those who are physical or assembly workers, including brisk walking, dancing, table tennis, ice skating, etc. The fourth category: heavy physical activity groups, those who are active or engaged in heavy physical strength, including swimming, running, various competitive games. Category 5: Extremely heavy physical activity groups, those who are engaged in extremely heavy physical labor or elite athletes, including boxing, boating, and mountaineering.

The basic metabolic calculation formula for men:

BMR = a + b * Wt+ c * Ht + d * Age―,

Where Wt is the weight of the tester, the unit is KG; Ht is the height of the tester, the unit is cm; Age is the age of the tester. a, b, c, d, e are coefficients:

a two 68

b=15. 9

c two 5· 9

d=-4. 8

The basic metabolic calculation formula for women: BMR = a+ b*Wt + c* Ht + d *Age,

a=678

b=9. 9

c=l. 8

D— 4. 8

Then multiply the coefficients of each level, you can get the daily calorie value: The first type: the static sitting population, the coefficient is 1. 2; The second category: the slightly active population, the coefficient is 1.475; The third category: moderately active population with a coefficient of 1. 55; the fourth category: heavy physical activity population with a coefficient of 1.77; and the fifth category: very heavy physical activity population with a coefficient of 2.22.

The automatic identification tester, the human body component test analyzer of the present invention uses three sets of multi-frequency signals as measurement signals, and can memorize the bio-resistance of the user at multiple frequencies. When the user uses the bio-information of the user, The body impedance is memorized in the memory. When the subject is measured again, the body composition test analyzer can identify the subject according to the bioelectrical resistance of the memory.

When measuring, place the analyzer's glass weighing pan on the ground. First, input the personal biological data of the testee's gender, age, height and physical activity intensity level using the keyboard. Then you can start the analysis of the body weight, body fat percentage, body water content, muscle content in the human body and human bone mineral content, and analyze the calorie value that the human body needs to consume every day. The measurement results are displayed on the display. It can also be connected to an external device, the measurement results are analyzed, and it is more direct and convenient to use.

Claims

1. A body composition analyzer for measuring body resistance of a human body, characterized in that the analyzer is used for measuring body weight, body fat percentage, moisture rate, muscle rate, body bone mineral content, and calculating human body's daily metabolism. And the power required for human biological activities

Amount, identify the user, and pass the measured data to other external devices and internal devices, including: Weighing scale weighing pan, 4 weighing sensors connected to the weighing pan; Used to display human body weight and human body moisture, fat a liquid crystal display (LCD) with muscle and bone mineral components and a printed circuit board (PCBA) connected thereto;

4 conductive electrodes for the measurement of human bioelectrical resistance;

begging

Keyboard circuit for user input of personal data; memory circuit; wireless transmission circuit;

USB circuit.

2. The body composition analyzer for measuring body resistance of a human body according to claim 1, wherein: said printed circuit board (PCBA) comprises: an 8-bit microcontroller (MCU); said 8-bit micro a controller (MCU), wherein an input/output terminal is connected to the waveform conversion and the input of the constant current source circuit (1A); the waveform conversion and the output end of the constant current source circuit are connected to one conductive electrode sheet; The printed circuit board (PCBA) has two heel counter circuits (4A, 4B) whose input 'ends are respectively connected to one end of the electrode piece (2A) and the selection switch (1C); the output ends of the follower circuit are respectively Connected to the input of the operational amplifier (5A); An output of the operational amplifier is coupled to an input of the filter circuit (6A); an output of the filter circuit is coupled to an input of the rectifier circuit (7A); an output of the rectifier circuit is coupled to another filter The input of the circuit (8A) is connected; the output of the other filter circuit (8A) is connected to one end of the 8-bit microcontroller, and the other filter circuit (8A) outputs a signal to the interior of the 8-bit microcontroller. Select the circuit (10A).

3. The body composition analyzer for measuring body resistance of a human body according to claim 1, wherein: an input end of the selection circuit (10A) of the 8-bit microcontroller and an output end of the load cell and The output of the other filter circuit (8A) is connected; the 8-bit microcontroller, wherein an input/output terminal is connected to the waveform conversion and the input of the constant current source circuit (1A), and outputs a square wave of a plurality of frequencies Signal to waveform input and input to the constant current source circuit;

The square wave signal of the plurality of frequencies output by the 8-bit microcontroller is a square wave of three groups of frequencies, the first group is a group of square wave signals with a center frequency of 17 kHz, and the second group is centered at 54 kHz. a set of square wave signals of frequency, the third group is a set of square wave signals with a center frequency of 100KHZ;

The square wave of the three sets of frequencies has a duty ratio of 1:1.

4. The body composition analyzer for measuring body resistance of a spectrum according to claim 1, wherein: the four conductive electrodes provided on the weighing pan are divided into two groups of left and right, two in each group, respectively In contact with the left and right feet, each component is a front electrode piece and a rear electrode piece,

• Contact the tester's sole and heel, respectively;

The electrode piece (2A) in contact with the left foot, respectively, and the output of the waveform conversion and constant current source circuit (1A), the input of the follower (4A), and another selection switch (1B) Connected to one end;

The electrode sheets (2B) in contact with the left heel are respectively connected to one end of another selection switch (1B) and one end of the digital adjustable potentiometer (1D);

The other end of the digital adjustable potentiometer is connected to one end of the selection switch (1C); the electrode piece (3A) in contact with the right foot and the electrode piece (3B) and the selection switch (1C) in contact with the right heel Connected to one end;

The electrode material of the electrode sheet is an electroplated conductive coating material.

5 . The human body composition analyzer for measuring body resistance of a human body according to claim 1 , wherein: the keyboard circuit has three keyboards, which are respectively set (SET), up (UP), and down. (DOWN) key;

The SET button is used to set the start and end of the user and the data selected by the user to confirm input into the microcontroller (MCU) and the memory circuit, the up (UP) and down

The (DO 丽) button is used to select the user's personal data;

The keyboard is used to select a user number of the user, and input the gender, age, height, and daily physical activity level of the user;

The user's daily physical activity level is divided into five exercise levels.

6. A method for measuring a body fat rate by a spectrum, wherein: the measurement is divided into two time periods, the first time period is a measurement of a human body resistance signal, and the second time period is a measurement of a reference resistance; The time period includes the following steps: a square wave signal of not less than 3 frequencies is outputted by an input/output terminal of an 8-bit microcontroller (MCU), and the square wave signal is a group of square waves centered at -54 KHZ The signal, the square wave signal is converted into a set of sinusoidal crossover signals of the corresponding frequency through the waveform conversion and the constant current source circuit, and the sinusoidal crossover signal enters the human body through the two electrodes contacting the left sole of the human body and the left heel, and then touches the right The two electrodes of the sole and the right heel enter the detection circuit, and the digital signal of the human body resistance after analog-to-digital conversion is input to the 8-bit micro via the 2-level amplification and 2-stage filtering through the analog-to-digital converter of the microcontroller (MCU). The controller (MCU) core; the second period includes the following steps: The digital potentiometer outputs the signal to the detection circuit, and is subjected to analog-to-digital conversion by a microcontroller (MCU) analog-to-digital converter through 2-stage amplification and 2-stage filtering. The measured digital signal of the digital potentiometer is input to an 8-bit microcontroller (MCU) core; an 8-bit microcontroller (MCU) calculates the body resistance according to the human body resistance signal and the potentiometer reference signal, according to the body resistance and The personal biometric information of the tester input in advance calculates the body fat percentage.

7. A method for measuring a human body moisture rate, a human muscle rate, a human bone mineral content, wherein the measurement is divided into two time periods, the first time period is a measurement of a human body resistance signal, and the second The first period is the measurement of the reference resistance. The first period includes the following steps: An input/output terminal of an 8-bit microcontroller (MCU) outputs two groups of square wave signals of a small number of three frequencies, respectively, to measure human water. The square wave signal of a group of frequencies is a square wave signal measuring a human body muscle rate and a human bone mineral content with a square wave signal centered at 17KHZ, and is a square wave with a center frequency of 100KHZ. The signal, the square wave signal is converted into a set of sinusoidal crossover signals of the corresponding frequency through the waveform conversion and the constant current source circuit, and the sinusoidal crossover signal enters the human body through the two electrodes contacting the left sole of the human body and the left heel, and then contacts the right foot. And the 2 electrodes of the right heel enter the detection circuit, and the body resistance after analog-to-digital conversion is performed by the analog-to-digital converter in the microcontroller (MCU) through 2-stage amplification and 2-stage filtering. The digital signal is input to the 8-bit microcontroller (MCU) core; the second period includes the following steps: The digital potentiometer outputs the signal to the detection circuit, which is amplified by 2 stages, filtered by 2 stages, and passed through the microcontroller (MCU). The analog-to-digital converter performs analog-to-digital conversion of the potentiometer reference digital signal, input to 8-bit micro control The controller (MCU) core; the 8-bit microcontroller (MCU) calculates the body resistance based on the human body resistance signal and the digital potentiometer reference signal, and calculates the body moisture rate based on the body resistance and the pre-entered tester's personal biological information. , human muscle rate, human bone mineral content. '

8. A method of measuring a body's daily metabolism and calorie value required for human biological activity, comprising the steps of: the tester inputs his or her physical activity intensity category, gender, height and age data through a keyboard, the physical activity The intensity category is divided into 5 motion levels. The load cell transmits the sensed weight signal to an 8-bit microcontroller (MGU), an 8-bit microcontroller (MCU), which calculates the tester's daily metabolism and people.