CN1085336C - Measurement method and device for non-anticoagulant apparent viscosity of blood - Google Patents

Abstract

In the present invention, liquid to be measured is both accelerated and flows through a U-shaped pipe by utilizing a precision transmission mechanism and a sealed pneumatic technique, and the pressure difference of the liquid in the pipe and the variation data of liquid shear rates with time are measured by a micropressure sensor in real time. The apparent viscosity of non-anticoagulated blood can be calculated in real time by A/D conversion and microcomputer processing. The present invention can also be used for detecting the apparent viscosity of other liquid. The measurement instrument can automatically absorb and discharge samples under the control of a computer. The present invention has the characteristics of high measurement precision, easy operation, etc.

Description

A kind of method and device of measuring non-anticoagulant apparent viscosity of blood

The present invention is applicable to the measurement of the apparent viscosity of one of non-Newtonian fluid rheology characteristic, is specially adapted to measure non-anticoagulation method of viscosity and device.

For treating and preventing many diseases, the measurement of blood viscosity is important and effective key factor.Present surveying instrument is broadly divided into two big classes, and rotary viscosimeter and capillary viscosimeter are no matter but the sort of instrument all can only carry out anticoagulant test.Can influence its rheological characteristics and add other material in blood, and influence the effect that factor produced of hemorheology performance in the blood, retinue's collection blood plays spent time length and changes.Therefore, the best method of measuring blood viscosity is to detect with live body (can't harm), or does not add anti-coagulants promptly take out i.e. survey under near physiology rheology environment.

Traditional capillary viscosimeter produces the driving force of fluid to be measured by gravity or atm difference, and true the flowing of liquid is not at the uniform velocity stable pipe stream, but the calculating of viscosity all is at the uniform velocity to stablize computing formula that pipe flows down, easily to produce systematic error.

The purpose of this invention is to provide a kind of method of easy quick measurement liquid apparent viscosity and realize the device of this method.The gas circuit sealing can make liquid flow velocity controlled in real time under precision drive and computer control during this device work, reaches and promptly takes out the purpose of promptly surveying, and overcomes non-measuring error of at the uniform velocity bringing and yield stress to tonometric influence.

Key problem in technology of the present invention is: behind the puncture blood collecting, under computer control, utilize the blood drawing of precision drive mechanism and airtight Pneumatic method, in the suction U type pipeline, even again acceleration is discharged blood sample after stablizing from pipeline, drains in the sample tube.In the stock layout process, two pressure transducers detect the pressure differential at the horizontal capillary tube segment of U type pipe two ends and the data on flows of liquid wherein in real time, according to formula＜1 of deriving voluntarily 〉,＜5 and＜6 can obtain apparent viscosity η _aStock layout cleans the back and uses dry gas drying pipeline inside.

With reference to the accompanying drawings the present invention is described in detail below, Fig. 1 provides the formation synoptic diagram of apparatus of the present invention.

The present invention includes body part, test section and the control section of measuring the rheology environment; The test section is made of pressure transducer, amplifier, A/D converter, liquid level detector; Control section is made of cylinder, motor and driver thereof, solenoid valve, relay, mechanical transmission mechanism and microcomputer; It is characterized in that measuring rheology environment body is U type pipe, can provide the U type of making near the material of blood flow environment under Human Physiology condition pipeline with glass or other, and the horizontal liquid of U type pipeline band gateway.The left VERTICAL TUBE internal diameter of U type pipe is 8mm or 5mm, and length is 100mm or 60mm, and internal diameter is uniformity along its length, and the top is provided with pressure tap, driving pressure hole, oven dry hole; Horizontal capillary inner diameter is about 1mm, long 270mm, and internal diameter is uniformity along its length, and horizontal kapillary and right VERTICAL TUBE interface are established a horizontal liquid gateway; Right VERTICAL TUBE is provided with liquid level detector, solenoid valve, pressure tap from bottom to top successively, top seal, in the right VERTICAL TUBE between pressure tap and solenoid valve internal diameter be 0.3～0.5mm.The liquid gateway is divided into two-way, and one the tunnel is connected on the silicone tube of band piercing needle through solenoid valve (16), and another road is through solenoid valve (17) sewer pipe that runs in.(1), (2) are micro-pressure sensors among Fig. 1, (4), (5), (16), (17) are solenoid valves, (7) be microcomputer, (6) are A/D converters, and (8) are temperature sensors, (9) be temperature controller, (10) be well heater, the component models that (3) are made up of cylinder, precision mechanical transmission mechanism, motor and driver thereof, (15) are the oven dry holes, (19) be the driving pressure hole, (20) and (21) are pressure taps.Pressure tap connects micro-pressure sensor, driving pressure hole relay part module (3), and cylinder is driven through mechanical transmission mechanism by motor, and the oven dry hole connects solenoid valve (4).Computing machine is according to the needs of measuring method, the break-make of controlling each solenoid valve is to open or to turn-off its place pipeline, control motor promotion cylinder pushes away or roping is moved, two pressure transducers send computing machine (7) through A/D converter (6) with signal, and the DI/DO interface of computing machine is connected on drive motor driver, solenoid valve (4), (5), (16), (17) and the liquid level sensor (12) of cylinder.A/D and DI/DO interface adopt the module of buying on the market.In the frame of broken lines is (14) 37 ± 0.1 ℃ of flat-temperature zones, air bath.The temperature of flat-temperature zone is by the temperature control subsystem controls; The closed loop temperature control system is by thermistor (8), and temperature controller (9) and well heater (10) are formed, and adopts electric bridge input type closed loop switching system.What Fig. 2 provided is the temperature control circuit synoptic diagram.Module S is a reference power supply among Fig. 2, and Rt is a thermistor.Thermistor detects the flat-temperature zone temperature, and converts electric signal to, and through bridge arm ratio, the real-time control heater of its difference heats or stops heating, to keep the temperature controlled region temperature stabilization at 37 ± 0.1 ℃.Computing machine (7) is through A/D converter timing sampling temperature value, to monitor the working condition of temperature control system.

The present invention's blanket gas flowing control method is constructed an environment that satisfies following notional result service condition, and can be used to measure few sample, and requires the non-anticoagulant apparent viscosity of blood of big shear rate scope.To the gradual Guan Liuyou of non-Newtonian fluid: ${\mathrm{\&tau;}}_{\mathrm{\&omega;}}=R[P\left(t\right)-\mathrm{L\&rho;}\frac{\mathrm{dU}\left(t\right)}{\mathrm{dt}}]/2L----<1>$ $\stackrel{\&CenterDot;}{\mathrm{\&gamma;}}\left({\mathrm{\&tau;}}_{\mathrm{\&omega;}}\right)=\frac{1}{\mathrm{\&pi;}{R}^3}[3Q+P\frac{\mathrm{dQ}}{\mathrm{dP}}]----<2>$ P is the pressure reduction at the horizontal kapillary of U type pipe two ends in the formula, and R is its inside radius, and Q is its pipe inner volume flow, and d is a differential sign, and L is a level length capillaceous, and p is a density of liquid.

During measurement, top, U type pipe two top is the sealed thermostat quantitative gas, satisfies Boyle's law.By the Pneumatic Control Technology flow velocity of controlling level capillary liquid in pipe easily, do not contact during micro-pressure sensor work with fluid to be measured, can measure the pressure P 1 and the P2 at horizontal kapillary two ends indirectly by two pressure transducers, thereby make pressure reduction P and flow Q is as follows: $Q=-\frac{C_1}{P_1^2}{}^{d{P}_1}/_{\mathrm{dt}}+\mathrm{\&pi;}{R}_0^2\frac{d{l}_1\left(t\right)}{\mathrm{dt}}----<3>$ $P\left(t\right)=P_1\left(t\right)-P_2\left(t\right)+K_1\mathrm{\&rho;}-\frac{K_2\mathrm{\&rho;}}{P_1\left(t\right)}{K}_3\mathrm{\&rho;}{l}_1\left(t\right)----<4>$ Will＜3 〉,＜4〉formula to time diffusion and substitution＜2〉formula, can obtain the variation relation of apparent viscosity by following apparent viscosity definition with shear rate. ${\mathrm{\&eta;}}_a={\mathrm{\&tau;}}_{\mathrm{\&omega;}}/\stackrel{.}{\mathrm{\&gamma;}}\left({\mathrm{\&tau;}}_{\mathrm{\&omega;}}\right)----<5>$

The concrete steps that realize the method for the invention are as follows:

A) U type pipe (13) is inserted in the main body case (14), plug silicone tube (11), (18), be communicated with each passage of cylinder and circuit in pressure transducer (1), (2), solenoid valve (4), (5), (16), (17) and liquid level detector (12) and the component models (3).

B) start temperature control system, the temperature controlled region temperature stabilization is 37 ℃ of setting values (error is ± 0.1 ℃).C) computer control cylinder place initial position, solenoid valve (4), (5), (16), (17) are closed, and cut off gas circuit, make it sealing.Inhale sample behind the puncture blood collecting, solenoid valve (16) is opened, and cylinder slowly moves, and pressure transducer (1) detects liquid level, and blood drawing extremely left VERTICAL TUBE H is highly located, and stops blood drawing.D) solenoid valve (5) is opened, and the computer control cylinder is adjusted liquid level and highly located to the H that edits, and two VERTICAL TUBE top gas are sealed.E) cylinder, is promoted liquid and flows out from pipeline to terminal point by static uniformly accelerated motion, provides the continuous change procedure of corresponding O shear rate to maximum shear rate simultaneously, and micro-pressure sensor (1), (2) are gathered pressure signal in real time, and preserves after the A/D conversion.F) detergent line behind the stock layout, wash number can preestablish.Clean rear electromagnetic valve (4) and open, cylinder under motor-driven, the suction dry gas, solenoid valve (4) cuts out, and cuts off gas circuit, the cylinder counter motion is released gas from U type pipe Horizontal Exit.Solenoid valve (16), (17) this moment all open.G) after computer data is handled, calculate wall shear stress, wall shear rate by following formula

(τ _ω), thereby calculate apparent viscosity value under the different shear rates. ${\mathrm{\&tau;}}_{\mathrm{\&omega;}}=R[P\left(t\right)-\mathrm{L\&rho;}\frac{\mathrm{dU}\left(t\right)}{\mathrm{dt}}]/2L$ $\stackrel{\&CenterDot;}{\mathrm{\&gamma;}}\left({\mathrm{\&tau;}}_{\mathrm{\&omega;}}\right)=\frac{1}{\mathrm{\&pi;}{R}^3}[-\frac{3C_1\&CenterDot;d{P}_1\left(t\right)/\mathrm{dt}}{P_1^2\left(t\right)}+3\mathrm{\&pi;}{R}_0^2\&CenterDot;d{l}_1\left(t\right)/\mathrm{dt}+P\frac{\mathrm{dQ}}{\mathrm{dP}}]----<6>$ In the formula: $\mathrm{dQ}=[\frac{{2C}_1(d{P}_1\left(t\right)/\mathrm{dt}{)}^2}{P_1^3\left(t\right)}-\frac{C_1\&CenterDot;d^2{P}_1\left(t\right)/{\mathrm{dt}}^2}{P_1^2\left(t\right)}+\mathrm{\&pi;}{R}_0^2\&CenterDot;d^2{l}_1\left(t\right)/{\mathrm{dt}}^2]d\left(t\right)$ $\mathrm{dP}\left(t\right)=[d{P}_1\left(t\right)/\mathrm{dt}-d{P}_2\left(t\right)/\mathrm{dt}+K_2\mathrm{\&rho;}\frac{d{P}_1\left(t\right)/\mathrm{dt}}{P_1^2\left(t\right)}-K_3\mathrm{\&rho;}\&CenterDot;d{l}_1\left(t\right)/\mathrm{dt}]d\left(t\right)$ $P\left(t\right)=P_1\left(t\right)-P_2\left(t\right)+K_1\mathrm{\&rho;}-K_2\mathrm{\&rho;}\frac{1}{P_1\left(t\right)}-K_3\mathrm{\&rho;}{l}_1\left(t\right)$ K in the formula ₁, K ₂, K ₃Be the constant relevant, C with pipeline size ₁, C ₂Be the constant in the Boyle's law, R ₀Radius for cylinder.

H) show with printing and show and print the different shear rates of the fluid to be measured apparent viscosity value down and the shear rate value of correspondence, show the function curve of apparent viscosity number with the shear rate variation.The sampling number and the time interval can preestablish.

Claims (2)

1. a device of measuring liquid apparent viscosity and non-anticoagulant apparent viscosity of blood comprises body part, test section and the control section of measuring the rheology environment, and the test section is made of pressure transducer, amplifier, A/D converter, liquid level detector; Control section is made of cylinder, motor and driver thereof, solenoid valve, relay, mechanical transmission mechanism and microcomputer; It is characterized in that measuring rheology environment body is U type pipe, and the left VERTICAL TUBE internal diameter of U type pipe is 8mm or 5mm, and length is 100mm or 60mm, and internal diameter is uniformity along its length, and the top is provided with pressure tap, driving pressure hole, the oven dry hole; Horizontal capillary inner diameter is about 1mm, long 270mm, and internal diameter is uniformity along its length, and horizontal kapillary and right VERTICAL TUBE interface are established a horizontal liquid gateway; Right VERTICAL TUBE is provided with liquid level detector, solenoid valve, pressure tap from bottom to top successively, top seal, in the right VERTICAL TUBE between pressure tap and solenoid valve internal diameter be 0.3～0.5mm; The driving pressure hole connects the component models of being made up of cylinder, precision mechanical transmission mechanism, motor and driver thereof; The liquid gateway is divided into two-way, and one the tunnel is connected on the silicone tube of band piercing needle through solenoid valve (16), and another road is through solenoid valve (17) sewer pipe that runs in.

2. method of utilizing the described device of claim 1 to measure the liquid apparent viscosity fast, its step comprises: inhale that sample, adjustment, control, data acquisition, apparent viscosity calculate, the apparent viscosity value shows and print, it is characterized in that:

1. after puncture blood collecting is inhaled sample, open solenoid valve (5), highly locate at left VERTICAL TUBE H by computing machine (7), pressure transducer (1), component models (3) control level stability;

2. under computer control, cylinder is by predetermined regular movement, liquid is flowed out from the pipeline gateway through horizontal kapillary, and flow velocity increases gradually by 0, and computing machine utilizes pressure transducer (1) and (2), the horizontal kapillary pressure at two ends of liquid level detector (12) real-time sampling data;

3. after computer data is handled, determine the apparent viscosity of the liquid of surveying automatically by following formula, ${\mathrm{\&tau;}}_{\mathrm{\&omega;}}=R[P\left(t\right)-\mathrm{L\&rho;}\frac{\mathrm{dU}\left(t\right)}{\mathrm{dt}}]/2L$ $\stackrel{\&CenterDot;}{\mathrm{\&gamma;}}\left({\mathrm{\&tau;}}_{\mathrm{\&omega;}}\right)=\frac{1}{\mathrm{\&pi;}{R}^3}[-\frac{3C_1\&CenterDot;d{P}_1\left(t\right)/\mathrm{dt}}{P_1^2\left(t\right)}+3\mathrm{\&pi;}{R}_0^2\&CenterDot;d{l}_1\left(t\right)/\mathrm{dt}+P\frac{\mathrm{dQ}}{\mathrm{dP}}]$

4. after the pipeline stock layout cleans, dry with dry gas in the pipe.

Images