CN101653627A - Digital medical ultrasonic bubble detector - Google Patents

Abstract

A digital medical ultrasonic bubble detector is composed of a light-emitting diode, an ultrasound transmitting transducer, a probe, a control circuit board, a fastener, a signal output line, a back cover and an ultrasound receiving transducer. The top of the probe is provided with a groove and a pipe passes through; the ultrasound transmitting transducer and the ultrasound receiving transducer aretwo piezoelectric ceramic oscillator plates which have same parameters and are symmetrically adhibited to the outer walls at both sides of the groove firmly; and the light-emitting diode are equippedto the top of the probe. When the pipe is filled with liquid after the transmission of ultrasound, an ultrasound echo pulse exists in the pipe; if the bubble exists, the echo pulse disappears immediately. The electronic circuit of the invention determines whether the echo pulse is qualified to a preset value. If the echo pulse is qualified, the object in the pipe is determined to liquid and the light-emitting diode at top of the probe is lightened; If the echo pulse is not qualified, the existence of the bubble is determined and the light-emitting diode is turned off.

Description

Digital medical ultrasonic bubble detector

Technical field:

The present invention relates to a kind of sensing device of surveying bubble in the pipeline fluid, particularly a kind of digital medical ultrasonic bubble detector.

Background technology:

The detector of bubble in the existing measurement fluid circuit, multiple optics or continuous ultrasound wave detector are arranged, its principle is light intensity signal or the ultrasonic signal intensity that pipeline is crossed in direct detection transmission, and judges in the pipeline it is liquid or bubble according to the variation of the voltage signal after the conversion.Its common characteristic is all to belong to the analog circuit category, sensitivity adjusting complexity, to the piping material bad adaptability, and such environmental effects is responsive to external world, with the microcontroller interface complexity.The optical detection mode is subject to the ambient light light intensity and disturbs, and to the transparency of pipeline, consistency of colour requires high.In continuous ultrasound ripple detection mode, ultrasonic emitting continues to carry out, and has both comprised the transmitted wave that directly penetrates pipeline in the signal that receptor is received, comprises the pipeline internal reflection echo that ripple thus causes again.Two types ripple mingles together, has increased desired signal identification difficulty greatly, causes accuracy of detection low, the rate of false alarm height, and the production debugging complexity, concordance is poor.At some medical domains, feed back such as human transfusion and blood component, above-mentioned detector might cause the bubble that exists in the pipeline to enter the blood of human body blood circulation uncontrollably, thereby causes blood circulation local air thromboembolism, and health is caused serious harm.

Summary of the invention:

Present situation in view of the prior art existence, the objective of the invention is the defective that exists at present prior art, design a kind of to bubble certainty of measurement height, response in the pipeline liquid in time, be not subject to extraneous factor influence, adaptability strong, debug the sensing device of digital medical ultrasonic bubble detection easily.

The present invention achieves the above object by following technical measures:

This digital medical ultrasonic bubble detector, by light emitting diode, the emission ultrasonic transducer, detecting head, control circuit board, securing member, output line, bonnet, the reception ultrasonic transducer constitutes, the detecting head top has a groove, there is the medical macromolecular materials pipeline to pass through in the groove, it is characterized in that launching ultrasonic transducer and receiving ultrasonic transducer is that two parameters are identical, the symmetry firm attachment is in the piezoelectric ceramics vibration sheet of groove both sides outer wall, light emitting diode is loaded on the detecting head top, emission ultrasonic transducer and reception ultrasonic transducer tow sides are respectively drawn one group of two line, link to each other with control circuit board respectively with the light emitting diode line, the output line of control circuit passes from the bonnet bottom, and control circuit board and bonnet are in aggregates by securing member and detecting head assembling.

Above-mentioned control circuit can be taken place by signal, signal amplification filtering, Digital Signal Processing three partial circuits are formed, signal generation divide by the time base, interrupted wave generation circuit, ultrasonic Sasser generation circuit are formed; Signal amplification filtering part is extracted circuit by signal amplification circuit, echo-signal and is formed; The Digital Signal Processing part is by pulse-scaling circuit, the logical judgment output circuit is formed, Shi Ji, interrupted wave generation circuit is base 1 and the output of Shi Ji 2 two-way sometimes, time base 1 outfan extracts circuit with echo-signal respectively and is connected with pulse-scaling circuit, time base 2 outfans are connected with pulse-scaling circuit with ultrasonic concussion wave generation circuit respectively, the outfan of ultrasonic concussion wave generation circuit is connected with the emission ultrasonic transducer, the outfan that receives ultrasonic transducer is connected with signal amplification circuit, the outfan of signal amplification circuit extracts circuit with echo-signal and is connected, echo-signal is extracted circuit output end and is connected with pulse-scaling circuit, the pulse-scaling circuit outfan is connected with logic judging circuit, and the outfan of logic judging circuit links to each other with led pins.

In order to improve anti-extraneous factor interference performance and to improve detector to there being the pipeline adaptability of nuance, guarantee the bubble in the reliable detection liquid, base when the present invention has designed in electronic circuit, interrupted wave generation circuit and ultrasonic concussion wave generation circuit, adopted unique interrupted ultrasonic emitting, make alternate supersonic oscillations drive the signal of telecommunication and be converted to ultrasound wave and emission through the emission ultrasonic transducer, penetrate the detected liquid in interior pipeline of groove and the pipeline, receive by the reception ultrasonic transducer that is installed on the groove opposite side, simultaneously, Shi Ji, interrupted wave generation circuit extracts circuit with echo-signal and combines, the extraction and analysis transmitting terminal stops to launch the echo-signal that exists in the ultrasound wave moment pipeline, masks the interference of direct transmission signal fully, extracts echo-signal accurately and reliably from the signal that receives.

In order to guarantee amplification to high frequency weak signal, the present invention's signal amplifier in signal amplification circuit filter uses the long-pending current mode operational amplifier of high gain-bandwidth, simultaneously, with the echo-signal after the processing and amplifying, directly be converted to digital pulse signal and carry out pulse bandwidth filtering, counting processing, improved the detector capacity of resisting disturbance greatly.This pick off to micro-bubble reaction fast, can be under pipeline 100ml/ minute flow velocity the bubble of reliable detection volume 〉=0.05ml, response time is less than 30ms.

The sensitivity of digital medical ultrasonic bubble detector of the present invention is decided by pulse count value.With the step-by-step counting standard value be provided with the sensitivity that improves detector less than normal, otherwise then reduce the sensitivity of detector.The counting standard value can realize by electrical switch toggle count device pin wiring break-make.Therefore this detector does not have any traditional adjustable resistance or electric capacity, has reduced debugging difficulty, guarantees very high homogeneity of product.And also very simple with MPI, directly can realize the programme-control of sensitivity by microprocessor control electrical switch.

Because the present invention has adopted piezoelectric ceramics vibration sheet as emission, receiving transducer spare with have the electronic control circuit of unique texture, make digital medical ultrasonic bubble detector of the present invention have accuracy of detection height, the reduction of production difficulty, good product consistency, the adaptable remarkable advantage of vulnerability to jamming and pipeline.

Description of drawings:

Fig. 1 digital medical ultrasonic bubble detector structural representation

Fig. 2 control circuit board circuit block diagram

Fig. 3 signal generation parallel circuit figure

Fig. 4 signal condition filtering partial circuit figure

Fig. 5 digital processing partial circuit figure

The specific embodiment:

Embodiment 1

Shown in Figure 1 is the structure applications of this digital medical ultrasonic bubble detector.As seen from the figure, this digital medical ultrasonic bubble detector is made of light emitting diode 1, emission ultrasonic transducer 2, light emitting diode line 3, emission ultrasonic transducer line 4, detecting head 5, control circuit board 6, securing member 7, output line 8, bonnet 9, reception ultrasonic transducer line 11 and reception ultrasonic transducer 13, detecting head 5 tops have a groove 10, having medical macromolecular materials pipeline 14 to pass through in the groove, is detected fluid 12 in the pipeline 14.

Light emitting diode 1 is installed in detecting head 5 tops, and is connected with control circuit board 6 by light emitting diode line 3.Emission ultrasonic transducer 2 and reception ultrasonic transducer 13 symmetries are adhesive in detecting head groove 10 both sides outer walls.Emission ultrasonic transducer 2 tow sides are drawn one group of totally two emission ultrasonic transducer line 4, and link to each other with control circuit board 6, receive the ultrasonic transducer tow sides draw one group totally two reception ultrasonic transducer lines 11 also link to each other with control circuit board 6.The output line 8 of control circuit board passes from the through hole of bonnet 9 bottom center.Control circuit board 6, bonnet 9 assemble in aggregates by securing member 7 and detecting head 5.At detecting head 5 crown centers one groove 10 is arranged, groove 10 is embedded in tested macromolecule medical pipeline 14, has detected fluid 12 to pass through in the macromolecule medical pipeline 14, is isolated by this macromolecule medical pipeline 14 between detected fluid 12 and the detecting head 5.Detection means does not contact with fluid to be measured in the whole testing process.

Control circuit board 6 circuit block diagrams are made up of signal generation, signal amplification filtering, Digital Signal Processing three parts as shown in Figure 2.Signal generation divides to produce to be modulated with discontinuous wave and sonic oscillation ripple, and the two sends ultrasound wave by W1 path drives emission ultrasonic transducer after inner modulation.In the present embodiment, the supersonic oscillations Frequency Design is the 4MHz square wave, dutycycle 1: 1, and interrupted frequency of modulated wave is the 45KHz square wave, dutycycle 0.82: 1.This wave beam penetrates medical high polymer pipeline 14 and the interior liquid 12 of pipeline in the detecting head groove 10, be received ultrasonic transducer 13 and receive and be converted into ultra-weak electronic signal, this signal of telecommunication is sent to control circuit partitioned signal amplification filtering part via the W2 path, its amplitude is exaggerated and is converted to the Transistor-Transistor Logic level digital signal, the T1 signal of binding signal generation part generation carries out Filtering Processing again, the spuious pulse signal that shielding direct wave and multiple reflection ripple cause, extract the echo pulse signal that needs, and export the Digital Signal Processing part to by the ECHO path.The T1 that part produces takes place in Digital Signal Processing part binding signal, logical judgment is counted and made to the signal that the T2 signal transmits the ECHO path. when the echo impulse count value that receives during, be judged as the discovery bubble less than preset value 8; When the echo impulse count value that receives during, be judged as and do not find bubble more than or equal to preset value 8.After judging, use for other control circuit and light emitting diode by BK path, the output of B path respectively.

The each several part circuit is described below:

Signal generation divide by the time base, interrupted wave generation circuit and sonic oscillation wave generation circuit constitute.In Fig. 3, form indirect feedback-type non-steady-state oscillation circuit by time-base integrated circuit U1A NE556D and capacitor C 4, resistance R 1, R2.U1A the 5th foot output 45KHz square-wave signal is as the T1 signal.Constitute pulse enable type monostable circuit by U1B, R3, R6, C6, its triggering signal is provided by U1A the 5th foot output signal, this signal input U1B the 8th foot is as the burst enable signal of monostable circuit, thereby make U1B the 9th foot output T2 signal, pull-up resistor R5, R4 make T1,2 signal levels meet the TTL signal level.

U6A among the hex inverter 74HC04D, U6B, R10, R11, C10 constitutes the not gate self-maintained circuit, produce 4MHz supersonic oscillations signal by this circuit, because ultrasound emission is intermittently to carry out, circuit starting of oscillation and failure of oscillation are by the T2 control (this control signal is by the input of U6A the 1st foot) of U1B the 9th foot output, thereby form the supersonic oscillations signal after the modulation, this signal is exported from W1 by U6C the 6th foot and U6D the 8th foot parallel connection through the buffering back, be sent to the emission ultrasonic transducer through the ultrasonic transducer line, and then driving emission ultrasonic transducer sends ultrasound wave to receiving ultrasonic transducer.After the reception ultrasonic transducer is received ultrasonic signal, acoustic signals is converted into the signal of telecommunication, deliver to control circuit board W2 place by reception ultrasonic transducer line and carry out amplification filtering, the amplification filtering circuit theory is seen Fig. 4, LM359M current mode dual operational amplifier U4A, U4B, R13, C9, R14, R15, R16, R17, R18, R19, R20 constitute two-stage signal and amplify, and the signaling conversion circuit that is made of U5A, Q2, R24 in 74HC132D four NAND gate circuits is converted to this voltage signal the pulse signal of 5V subsequently.Comprised current ultrasonic signal, the ultrasound echo signal last time of directly penetrating that receives in this pulse signal, (＞the signal that receives during 4.5V) proposes the T1 signal high level that U1A the 5th foot is produced by U5B subsequently, this signal is the ultrasonic echo pulse signal, simultaneously other unwanted signal pulse is filtered out, and export the 1st foot of Digital Signal Processing partial circuit U2A from ECHO to.

Digital Signal Processing partial circuit figure sees Fig. 5, form by pulse-scaling circuit and logical judgment output circuit 2 parts, pulse-scaling circuit is by two 4 the binary counter U2A of 74HC393D, U2B and 74HC4040D 12 bit synchronization binary counter U3 form, at first in conjunction with the T2 signal that U1B the 9th foot produces the binary pulse of input is counted by U2A, count value greater than setting after, then produce spill over and import U2B into and U3, U2B carries out second level step-by-step counting in conjunction with the T1 signal that U1A the 5th foot produces to the spill over that imports into, if the step-by-step counting sum is thought full of liquid in the pipeline greater than 8, if have bubble in the pipeline, then the U2A count value does not reach the counting lower limit or surpasses lower limit but do not reach 8 as yet, binary counter can the output carry signal in the count cycle, will make zero in case the count cycle finishes its count value.U3 is 12 binary counters, and it does 12 samplings to the binary carry signal of U2 output, causes false triggering to avoid disturbing pulse once in a while.In 12 sampling processes, if U2 output exists an above low level (less than 0.5V) to have bubble to cause counted number of pulses not reach setting in the pipeline, U3 output low level then; If the lasting output of U2 12 high level (greater than 0.5V), i.e. full of liquid in the pipeline, then U3 output high level.U3 output signal and U2B output signal enter the rest-set flip-flop that U5C, U5D constitute as R signal and S signal, carry out level logic and judge.When in the ultrasonic bubble detector groove not in tubulature or the pipe of packing into when the bubble rest-set flip-flop be in reset mode, U5C output discovery air signal, BK is a low level.U5D exports high level, and light emitting diode B current potential is a high level, and light emitting diode extinguishes.Rest-set flip-flop is in set and hold mode during full of liquid in pipe in the ultrasonic bubble detector groove of packing into, U5C output discovery liquid signal, and BK is a high level.The U5D output low level, making light emitting diode B current potential is low level, light emitting diode is lighted.

Claims (4)

1, digital medical ultrasonic bubble detector, by light emitting diode (1), emission ultrasonic transducer (2), light emitting diode line (3), emission ultrasonic transducer line (4), detecting head (5), control circuit board (6), securing member (7), output line (8), bonnet (9), receive ultrasonic transducer (13), receiving ultrasonic transducer line (11) constitutes, the detecting head top has a groove (10), there is medical macromolecular materials pipeline (14) to pass through in the groove, it is characterized in that launching ultrasonic transducer (2) and receiving ultrasonic transducer (13) is two piezoelectric ceramics vibration sheets that parameter is identical, these two piezoelectric ceramics vibration sheet symmetry firm attachment are in groove both sides outer wall, light emitting diode (1) is loaded on detecting head (5) top, receive ultrasonic transducer (2) and launch ultrasonic transducer (13) tow sides separately a line (4) is respectively arranged, (11), link to each other with control circuit board (6) respectively with light emitting diode line (3), the output line (8) of control circuit board (6) passes from bonnet (9) bottom center, control circuit board (6), bonnet (9) is in aggregates with detecting head (5) assembling by securing member (7).

2, digital medical ultrasonic bubble detector according to claim 1, it is characterized in that control circuit is made up of signal generation, signal amplification filtering, Digital Signal Processing three partial circuits, signal generation divide by the time base, interrupted wave generation circuit, ultrasonic Sasser generation circuit are formed; Signal amplification filtering part is extracted circuit by signal amplification circuit, echo-signal and is formed; The Digital Signal Processing part is by pulse-scaling circuit, the logical judgment output circuit is formed, Shi Ji, interrupted wave generation circuit is base 1 and Shi Ji 2 two-way outfans sometimes, time base 1 outfan extracts circuit with echo-signal respectively and is connected with pulse-scaling circuit, time base 2 outfans are connected with pulse-scaling circuit with ultrasonic concussion wave generation circuit respectively, the outfan of ultrasonic concussion wave generation circuit is connected with emission ultrasonic transducer (2), the outfan that receives ultrasonic transducer (13) is connected with signal amplification circuit, the outfan of signal amplification circuit extracts circuit with echo-signal and is connected, echo-signal is extracted circuit output end and is connected with pulse-scaling circuit, the pulse-scaling circuit outfan is connected with logic judging circuit, and the outfan of logic judging circuit links to each other with light emitting diode (1) pin.

3, digital medical ultrasonic bubble detector according to claim 1 and 2, the size that it is characterized in that ultrasonic transducer are 10mm * 10mm * 1mm.

4, digital medical ultrasonic bubble detector according to claim 1 and 2 is characterized in that launching ultrasonic transducer and reception ultrasonic transducer symmetry firmly is pasted on groove both sides outer wall.

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