CN2472227Y - Electronic scale with human fat determining device - Google Patents

Abstract

The utility model relates to an electronic scale capable of measuring the human body fat content, which mainly comprises an electrode plate which is positioned on and combined with the upper surface of the scale, a human body impedance measuring circuit, a weight sensor and a signal processing circuit, a microprocessor MCU system, a display, a keyboard and other members. The utility model integrates the function of measuring the human body impedance further to measure the human body fat content with the function of measuring the human body weight. The utility model uses the correlativity between the potential drop of the human body by using the AC pulse current and the human body fat content, and combines the entered human body height and the age to measure the human body fat content. The measured human body weight and human body fat content are output by the display. In the daily life, people can measure the body fat content conveniently while measuring the weight.

Description

The electronic scales that has body fat assay function

The utility model belongs to technical field of measurement and test, further relates to a kind of electronic scales that has body fat assay function.

Body fat content is significant for estimating human body obese degree, nutritional status and health condition.Up to now, the method and the achievement of more existing mensuration body fat content.As isotope-labelling method, weight method, height and weight empirical algorithms, ultrasonic Method for Measuring, infrared rays survey method and human body impedance measuring method etc. under water.Wherein simple and easy to do in daily life method is height and weight empirical algorithms and human body impedance measuring method.For the height and weight empirical algorithms, can only be in the crowd of normal type rough assessor's body fat content in little scope, and,, also can't distinguish both fat contents though height and weight is identical for soft-fat type or athletic type.For the human body impedance measuring method, then be by distinguishing the different electrical impedance of human muscular tissue and body fat, and with the correlativity of body fat content, and judgement body fat content.This kind method has two kinds of embodiments: a kind of is only by measuring local impedance with the human epidermal electrode in contact; After another kind is measurement and the contacted local impedance of human epidermal,, estimate tested person's height, body weight, age input.Obviously, compare with measuring method such as weight method under water, the human body impedance measuring method should be that a kind of precision is lower than the evaluation method of weight method under water owing to just obtain the human body local impedance.But method is simple for this kind, for for controlling obesity, keep the bodily form, preventing that purposes such as some disease, body building from needing often to measure fat content, grasps the requirement of variation tendency, a kind of practicable method of can yet be regarded as.

Human body impedance measuring method in the past or measure the body local impedance merely and show limitation to objective thoroughly evaluating body fat content, otherwise after measuring human body impedance, need simultaneously by other method measure human body weight, height show inconvenient.

The purpose of this utility model is to overcome above-described deficiency, and provide a kind of human body impedance measuring and human body weighing are combined, the human body impedance that to measure by the vola and the body weight of measurement and height, the age of input are comprehensively judged by intelligent chip, provide a kind of electronic scales that has body fat assay function of body weight value and fat content value simultaneously.

The utility model comprises the battery lead plate that combines with the scale pan, human body impedance measuring circuit, LOAD CELLS and signal processing circuit, microprocessor system, display, keyboard etc.Its ultimate principle is: pole plate conduct and human body sole electrodes in contact, after the alternating-current pulse electric current feeds human body by pole plate, all can produce voltage drop being connected in a sample resistance and a tested human body place in the path with human body, this voltage drop signal is processed into human body impedance value and body weight for humans value with the load cell signal of handling through metering circuit in little processing, be processed into body fat content through mathematical model.A kind of expression way of mathematical model is: $\mathrm{Fat}=\frac{a_{1}H+a_{2}W+a_3\mathrm{Rm}+a_{4}Y+a_0}{{\mathrm{ce}}^{-(b_{1}H+b_{2}W)}}$ $\mathrm{Fat}(\%)=\frac{\mathrm{Fat}}{W}$ Wherein Fat is body fat value (kg), and Fat (%) is people's body fat content, and W is human body weight (kg), and H is human body height (cm), and Rm is the human body resistance value, and Y is tested person's age, a ₀, a ₁, a ₂, a ₃, a ₄, b ₁, b ₂, c is coefficient.In mathematical model, Rm and W are for recording parameter, and H and Y are through keyboard input parameter.

The utility model will be further described below in conjunction with accompanying drawing.

Fig. 1 is the utility model system construction drawing.

Fig. 2 is the metering system synoptic diagram.

Fig. 3 is electrode plate structure embodiment 1 synoptic diagram.

Fig. 4 is electrode plate structure embodiment 2 synoptic diagram.

Fig. 5 is a sample of signal principle schematic in the human body impedance measuring circuit.

Fig. 6 is a signal quantization embodiment synoptic diagram in the human body impedance measuring circuit.

Fig. 7 is a microprocessor MCU system principle synoptic diagram.

Fig. 8 is a strain-type weight sensor test circuit embodiment synoptic diagram.

Fig. 9 is a condenser type weight sensor test circuit embodiment synoptic diagram.

With reference to Fig. 1, battery lead plate 1 links to each other with the port of the human body impedance measuring circuit 3 that contains impedance conversion and rectification function with 2, and the signal after impedance conversion and rectification is linked to each other with the port of microprocessor MCU system 4 by the output terminal of human body impedance measuring circuit 3.The signal wire of LOAD CELLS 8 links to each other with weighing-up wave treatment circuit 7, and the signal after the processing is by the output terminal of weighing-up wave treatment circuit 7 and the port of microprocessor MCU system 4.Display 5 as the demonstration output block of weight and body fat content links to each other with the output terminal of microprocessor MCU system 4, links to each other with the I/O port of microprocessor MCU system 4 as the keyboard 6 of measured's height with the input block of non-measurement parameters such as age.

With reference to Fig. 2, metering system of the present utility model is that the naked foot of measured stands on the electronic scales scale pan 9, the vola sole of biped respectively with place the scale pan 9 on battery lead plate 1 and 2 contact.Weight measurement and human body impedance measuring are carried out simultaneously.

Electrode plate structure of the present utility model has two kinds of embodiment.With reference to Fig. 3, electrode plate structure embodiment 1 has represented to place the battery lead plate 1 and 2 on the scale pan 9 to have at least more than two can have a long-pending battery lead plate of certain surface with the human body sole is contacted.With reference to Fig. 4, electrode plate structure embodiment 2 represented to place the battery lead plate on the pan of a steelyard 9 has that two groups of above some electrode slices that are connected by lead form at least can with human body sole electrode in contact group 12,13.

With reference to Fig. 5, the alternating-current pulse signal is loaded on human body load Rm by battery lead plate 1,2, and the lead that links to each other with battery lead plate 1 is converted to d. c. voltage signal V1 through impedance conversion and rectification circuit (being made up of emitter follower and commutation diode) 10.An end that is connected on the sample resistance R in the alternating-current pulse loop links to each other with the input end of impedance conversion and rectification circuit (being made up of with commutation diode emitter follower) 11, and is reflected the d. c. voltage signal V2 of sample resistance R voltage drop signals by impedance conversion and rectification circuit 11 outputs.By following formula human body impedance Rm as can be known: $\mathrm{Rm}=\frac{V1-V2}{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="Y0023932000081.png,Y0023932000121.png"\; state="\{\{state\}\}">V</figure-callout>}2}*R$ Impedance conversion and rectification circuit 10 and 11 promptly are the ingredients of human body impedance measuring circuit 3.

With reference to Fig. 6, the embodiment of signal quantization in a kind of human body impedance measuring circuit.Series connection is connected to R1, R2, R3, R4, R5, R6, R7, R8, nine resistance of R9 between power supply VCC and ground, and the junction of per two resistance has eight lead-in wires and eight and selects eight input ends of an analog switch 4051 to link to each other.4051 output terminal extremely links to each other with the reference of comparer 393.D. c. voltage signal V2 (or V1) to the human body impedance sampling extremely links to each other with the input of comparer 393.The output stage output V0 of comparer 393, V0 is 0 or 1 logic level, is connected to an I/O mouth of microprocessor MCU system 4.4051 selection port A, B, C connects the I/O mouth from microprocessor MCU system 4.

With reference to Fig. 7, the AD mouth that d. c. voltage signal V1, the V2 of human body impedance sampling is connected to microprocessor MCU system 4 carries out the AD conversion.Quantification logic level V0 in a kind of human body impedance measuring circuit among embodiment Fig. 6 of signal quantization is connected to an I/O mouth of microprocessor MCU system.Weight sensor 8 is resonant force sensor, the output terminal of the output terminal of its oscillatory circuit and standard crystal oscillator M oscillatory circuit is connected to the D end and the CLK end of 7474D trigger respectively, and then forms difference frequency signal is exported to microprocessor MCU system 4 by the Q end a counter mouth metering frequency.

With reference to Fig. 8, strain-type weight sensor test circuit embodiment has represented that strain-type weight sensor Rb1 and other three resistance R b2, Rb3, Rb4 connect into the electric bridge form, the output terminal of electric bridge links to each other with the input end of electric bridge signal processing circuit 14, and the output terminal of electric bridge signal processing circuit 14 links to each other with the AD mouth of microprocessor MCU system 4.

With reference to Fig. 9, condenser type weight sensor test circuit embodiment has represented that condenser type weight sensor Cs is in parallel with resistance R c, two ends link to each other with the input end of RC oscillator signal treatment circuit 15 respectively, and the output terminal of RC oscillator signal treatment circuit 15 links to each other with a counter mouth of microprocessor MCU system 4.

The utility model will be being integrated in one by the function of measuring human body impedance and then measurement body fat content and the function that human body weight is measured, make it to become that to have the electronic scales device of measuring body fat assay function be purpose, be applied to that the measured measures body fat content easily in the daily life when measuring weight.

Claims (3)

1. electronic scales that has body fat assay function, it comprises and places pan of a steelyard upper surface and the battery lead plate that combines with the scale pan, human body impedance measuring circuit, weight sensor and signal processing circuit thereof, microprocessor MCU system, display, keyboard etc., it is characterized in that: battery lead plate 1 and 2 places the pan of a steelyard upper surface, and link to each other with the port of human body impedance measuring circuit 3, the signal after impedance conversion and rectification is linked to each other with the port of microprocessor MCU system 4 by the output terminal of human body impedance measuring circuit 3.The signal wire of LOAD CELLS 8 links to each other with weighing-up wave treatment circuit 7, and the signal after the processing is linked to each other with the port of microprocessor MCU system 4 by the output terminal of weighing-up wave treatment circuit 7.Display 5 as the demonstration output block of weight and body fat content links to each other with the output port of microprocessor MCU system 4, links to each other with the I/O port of microprocessor MCU system 4 as the keyboard 6 of height with the input block of non-measurement parameters such as age.

2. a kind of electronic scales that has body fat assay function as claimed in claim 1 is characterized in that: placing battery lead plate 1 and 2 on the scale pan 9 to have at least more than two can have a long-pending battery lead plate of certain surface with the human body sole is contacted.

3. a kind of electronic scales that has body fat assay function as claimed in claim 1 is characterized in that: place that battery lead plate on the scale pan 9 has that two groups of above some electrode slices that are connected by lead form at least can with human body sole electrode in contact group 12,13.

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