EP0205487A1 - Method and device for determining the cardiovasculary characteristics by external process and application thereof to cardiopathies - Google Patents

Method and device for determining the cardiovasculary characteristics by external process and application thereof to cardiopathies

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Publication number
EP0205487A1
EP0205487A1 EP19850906077 EP85906077A EP0205487A1 EP 0205487 A1 EP0205487 A1 EP 0205487A1 EP 19850906077 EP19850906077 EP 19850906077 EP 85906077 A EP85906077 A EP 85906077A EP 0205487 A1 EP0205487 A1 EP 0205487A1
Authority
EP
European Patent Office
Prior art keywords
time
doppler
successive
curve
computer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP19850906077
Other languages
German (de)
French (fr)
Inventor
Bernard Levy
Alain Tedgui
François BORNES
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Institut National de la Sante et de la Recherche Medicale INSERM
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Original Assignee
Commissariat a lEnergie Atomique CEA
Institut National de la Sante et de la Recherche Medicale INSERM
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Filing date
Publication date
Application filed by Commissariat a lEnergie Atomique CEA, Institut National de la Sante et de la Recherche Medicale INSERM filed Critical Commissariat a lEnergie Atomique CEA
Publication of EP0205487A1 publication Critical patent/EP0205487A1/en
Pending legal-status Critical Current

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Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/48Diagnostic techniques
    • A61B8/483Diagnostic techniques involving the acquisition of a 3D volume of data
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/06Measuring blood flow
    • A61B8/065Measuring blood flow to determine blood output from the heart
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/88Sonar systems specially adapted for specific applications
    • G01S15/89Sonar systems specially adapted for specific applications for mapping or imaging
    • G01S15/8906Short-range imaging systems; Acoustic microscope systems using pulse-echo techniques
    • G01S15/8979Combined Doppler and pulse-echo imaging systems
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/88Sonar systems specially adapted for specific applications
    • G01S15/89Sonar systems specially adapted for specific applications for mapping or imaging
    • G01S15/8906Short-range imaging systems; Acoustic microscope systems using pulse-echo techniques
    • G01S15/8993Three dimensional imaging systems

Definitions

  • the present invention creates a new method which makes it possible to instantly know essential characteristics such as cardiac output, speed of flow of blood, in particular in the aorta, acceleration at the start of systole and , therefore, it becomes possible to intervene very quickly, which is decisive for some patients, especially for mechanically ventilated patients with serious conditions.
  • the method for determining cardiovascular characteristics externally is characterized laughed at by determining the cross section of a blood vessel, by determining the distance between a substantially cross section of the blood vessel and part of the patient's body surface, by emitting inside regular time intervals of the ultrasonic bursts, in that the Doppler echo of said bursts is collected at a time interval corresponding to the distance separating the vessel from the part of the patient's body surface, in that '' the successively collected echoes are converted into directional Doppler signals, in that said directional Doppler signals are converted into digital signals, in that one alternately stores a number of digital signals which is a power of 2 in two buffers for short successive sampling time intervals, in that the digital signals coming successively from l are processed alternately by Fourier transformation and in real time 'and the other memory buffers to establish a frequency spectrum and. amplitudes corresponding to each sampling time, and in that the average frequency is calculated
  • Fmoy ⁇ (A 2 .F) ⁇ A 2 to obtain a curve as a function of time, each period of which is the image of a systole.
  • the invention also extends to a device for implementing the above method, device which by its realization can be produced in a small volume and at a low price given the specificity of its components intended to fill only a limited number of functions although in very short times, and thus the miniaturization that it is possible to carry out of the device makes it possible to implement it even outside intensive care units.
  • the information provided by the device can be obtained for the most part in direct reading, for example on a cathode-ray screen while allowing as much, possibly, graphic recordings at characteristic moments of a treatment or during the sudden evolution of the patient's condition.
  • the device comprises a transducer for the emission of bursts of ultrasound at regular time intervals and for reception of the resulting Doppler echo, a directional circuit for obtaining signals Directional Doppler, an analog to digital converter connected to the directional Doppler circuit, two buffer memories connected to the analog to digital converter and receiving alternately a number of significant image points of the directional Doppler signal, a computer connected to the two buffers and successively processing the illustrative data points stored in said buffer memories for the formation of a spectrum of amplitudes and frequencies respectively illustrating half of the significant points stored each time in each of the buffer memories, a first memory for storing the amplitudes and frequencies spectrum characteristics and a computer connected to said memory to perform at least the calculation ⁇ (A 2 . F)
  • the invention finds a particularly important application in the establishment of cardiovascular characteristics, in particular at the level of the ascending aorta.
  • the transducer is placed in the suprasternal fossa behind the manubrium, being directed downwards to intercept a section of the ascending aorta close to the sigmoid valves.
  • Fig. 1 is a block diagram of the device for implementing the method for determining cardiovascular characteristics, object of the invention.
  • Fig. 2 is an explanatory anatomical diagram.
  • Fig. 3 illustrates two curves for obtaining a Doppler signal.
  • Fig. 4 is a diagram illustrating a processing phase of the method of the invention.
  • Fig. 5 schematically illustrates a spectrum obtained by Fourier transformation from the Doppler signals illustrated schematically in FIG. 3.
  • Fig. 6 is an illustrative curve of cardiovascular characteristics obtained according to the invention in real time.
  • Fig. 7 is a curve illustrating a three-dimensional representation obtained according to the invention.
  • Fig. 8 illustrates the so-called three-dimensional representation obtained from the cardiovascular characteristics determined according to the invention from the curves of FIG. 6.
  • Figs. 9 and 9a are vector representations illustrating the speed of the blood cells in a vessel during a sampling time defined in relation to FIG. 3.
  • 1 designates a transducer for the emission of signal bursts and the reception of Doppler signals through a gate 2 leading to a processing circuit 3 for forming directional Doppler signals, that is to say all positive and for example between 0 and 7 KHz.
  • the transducer 1, door 2 and circuit 3 assembly is adjusted as illustrated in FIG. 3 to first obtain Doppler samples, that is to say that in successive time intervals T, T 1 ... T n , for example of 10 -4 s, first of all a burst of high frequency pulses for example at 4 MHz for a time t.
  • the frequency of the bursts of pulses is chosen taking into account the approximate known speed of the blood cells, generally between 0 and 150 cm / s in the ascending aorta during a systole so that the Doppler signal, that is to say the difference between the transmitted frequency and the received frequency, ie a directional frequency preferably included in the audible frequencies, for example between 0 and 7 KHz, as indicated above.
  • FIG. 2 To determine the cardiovascular characteristics at the level of the ascending aorta, the procedure is as illustrated in FIG. 2.
  • 4 designates the left ventricle of the heart
  • 5 designates the sigmoid valves
  • 6 the ascending aorta.
  • the transducer 1 is applied at the level of the suprasternal fossa 7, that is to say behind manubrium 8 of the patient and said head 1a is maintained so that its axis is substantially vertical and directed downward as illustrated by axis 9, so that said axis is approximately concentric to a cross section 10 of the part of the aorta ascending near the sigmoid valves.
  • An anatomical study can moreover be carried out for each patient concerned before the examination by means of an ultrasound observation making it possible to locate the section 10 at approximately 6 cm from the suprasternal pit 7 and, likewise, the aortic section at the Cut level 10 is normally known from tables or easily determined by ultrasound observation.
  • the time t 1 must be set to elapse between the end of the burst of high frequency pulses emitted during the time t and the opening of the door 2 making it possible to receive the Doppler echo.
  • the time t 1 is for example between 60 and 80 ⁇ s, the door 2 then remaining open for a time t 2 for example between 1 and 3 ⁇ s.
  • said time t 2 represents the sampling time of the Doppler frequency.
  • the section 10 has a diameter of approximately 3 cm and a thickness of between 0.75 and 2.25 mm when the level at which the echo is to be appreciated is 4.5 to 6 cm away from the receiving transmitting part of the transducer head 1a.
  • the directional Doppler signal from circuit 3 is applied to an analog-to-digital converter 11 intended for alternately loading two buffer memories 12 and 13 which are connected to a processing computer 14 in which said buffer memories are alternately discharged as illustrated diagrammatically in fig. 4.
  • each buffer memory 12, 13 receives successively a integer number of points, which is a power of 2 and, preferably, each memory receives 128 points constituting the digital image of the Doppler signal corresponding to a sampling time period of 5 ms.
  • the processing calculator 14 comprises a calculation software 14a causing it to perform a Fourier transformation for each of the data received alternately from one and the other memories in successive sampling time periods of 5 ms.
  • Fig. 5 shows that the processing computer 14 establishes, during each 5 ms period of time, a spectrum of 64 values of frequency F and 64 values of amplitude A.
  • the values of the frequencies and the amplitudes thus calculated during each lapse of time of 5 ms are stored in memories 15 of amplitudes and frequencies connected to a computer 16 (fig. 1) which, in the example described in the following , is designed to perform two types of calculations and which can therefore be constituted in the form of a unit specific to these only types of calculations, which allows it to be performed in reduced form and relatively inexpensively.
  • the computer 16 receiving the data from the memories 15 performs from each spectrum conforming to that of FIG. 5 an average frequency calculation in real time, that is to say as each spectrum is established.
  • each pulse I of the curve of FIG. 6 corresponds to the acceleration that the blood undergoes at the start of the systole, the front edge of said curve thus being a very important illustration of the cardiac state since the acceleration that the blood undergoes in the ascending aorta near the valves sigmoid is an image of the contractility of the heart muscle.
  • each pulse I also corresponds to the volume of blood ejected during systole, this volume can thus be easily calculated by the computer 16 which only has to carry out the integral of each pulse.
  • the section of the aorta is also known as explained in the foregoing, the product of the velocity by this section can also be easily executed by the computer to know the blood flow to each systole.
  • the curve of fig. 6 being a frequency curve as a function of time and this curve delimiting with precision the successive sytoles and diastoles, the durations of the latter are also determined in a simple manner.
  • the computer 16 is normally connected to a screen 17 making it possible to permanently display the characteristics calculated by the computer.
  • a keyboard 18 is associated with the computer 16 to allow the operator to store in memory for a more or less long time, for example 5 to 7 seconds, the coordinates of the curve of FIG. 6 and thus allow then to make a plot by means of a writer 19 of the data of the curve of FIG. 6 which have been frozen in memory for the time selected above. It can be seen from the above that, by the means described, the invention makes it possible, for example at each cardiac period, to know the blood volume ejected during systole, to know the ejection time, the maximum blood speed, maximum blood acceleration and cardiac output, results which allow them to appreciate the cardiovascular state and in particular the contractility characteristics of the muscle.
  • the method of the invention also extends to the determination and the visualization of the differences in speed of the blood glovules in the vessel studied by showing the results obtained in the form of a three-dimensional plot which thus appears in the manner a relief representation.
  • the amplitude and frequency spectra of the memory 15 are transferred to the computer 16 to be stored and processed there in deferred time, that is to say that the succession of amplitude and frequency data allows from the curve according to fig. 5 to trace at the end of each sampling time of 5 ms a first envelope of the spectrum as illustrated by the curve E 1 of FIG. 7.
  • the computer 16 is programmed to calculate and then trace the envelope E 2 of the spectrum of the second sampling time of 5 ms.
  • the plotting of the curve E 2 and of the following ones is carried out according to coordinates shifted in the time of regular measurements, images of the sampling time of 5 ms as indicated in fig. 7.
  • the calculation of the plot of the curves E 1 , E 2 ... E n of the envelopes of the successive spectra is carried out as shown in FIG. 7 so that only the parts of the envelopes not hidden by the preceding envelopes appear.
  • the three-dimensional trace described is obtained by acting on the keyboard 18 of the computer 16 to freeze in the main memory of the latter the data of the successive spectra at 64 amplitudes and 64 frequencies. memories 15 for a time, for example of about 10 seconds or more, to then allow and in delayed time the three-dimensional tracing over a significant period of time corresponding for example to a respiratory cycle, which then allows the observer to '' appreciate the cardiac cycles taking into account the interferences produced on the aortic circulation in the course of the respiratory cycles.

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Abstract

Dispositif comportant un transducteur (1) pour l'émission au niveau du manubrium de salves d'ultrasons à intervalles de temps réguliers et pour la réception de l'écho Doppler d'une coupe transversale provenant de l'aorte ascendante, un convertisseur analogique numérique des signaux Doppler, deux mémoires-tampons (12, 13) reliées au convertisseur (11) et recevant alternativement un nombre de points images du signal Doppler, un calculateur (14) traitant successivement les données illustratives des points emmagasinés dans les mémoires-tampons pour la formation d'un spectre d'amplitudes et de fréquences correspondant aux points significatifs emmagasinés dans chacune des mémoires-tampons, une mémoire (15) pour emmagasiner les valeurs des amplitudes et fréquences caractéristiques du spectre et un ordinateur (16) relié à ladite mémoire (15) pour effectuer et afficher le calcule (I), qui illustre chaque systole dans le temps.Device comprising a transducer (1) for the emission at the manubrium of bursts of ultrasound at regular time intervals and for the reception of the Doppler echo of a cross section coming from the ascending aorta, an analog-to-digital converter Doppler signals, two buffers (12, 13) connected to the converter (11) and alternately receiving a number of image points of the Doppler signal, a computer (14) successively processing the illustrative data of the points stored in the buffers for forming an amplitude and frequency spectrum corresponding to the significant points stored in each of the buffer memories, a memory (15) for storing the values of the amplitudes and frequencies characteristic of the spectrum and a computer (16) connected to said memory (15) to perform and display the compute (I), which illustrates each systole over time.

Description

Procédé et dispositif de détermination de caractéristiques cardic-vasculaires par voie externe et leur application aux cardiopathiesMethod and device for determining cardiovascular characteristics externally and their application to heart disease
Dans de nombreuses maladies cardiovasculaires, il est utile d'être à même de connaître le cycle hémodynamique d'un patient pour déterminer le traitement à lui appliquer et l'évolution de celui-ci. L'estimation clinique de l'état hémodynamique d'un patient conduit fréquemment à des erreurs de sorte que dans des cas graves, notamment dans le cas de patients ventilés mécaniquement, on est conduit à effectuer une cathétérisation cardiaque qui permet de vérifier rapidement l'évolution d'une thérapeutique. C'est ainsi qu'on utilise de plus en plus la cathétérisation dans des unités de soins intensifs pour contrôler le débit cardiaque de patients, en particulier par le procédé dit de "thermo-dilution".In many cardiovascular diseases, it is useful to be able to know the hemodynamic cycle of a patient to determine the treatment to be applied to it and its evolution. The clinical estimation of the hemodynamic state of a patient frequently leads to errors so that in serious cases, in particular in the case of mechanically ventilated patients, we are led to carry out a cardiac catheterization which makes it possible to quickly check the evolution of a therapy. This is how catheterization is used more and more in intensive care units to control the cardiac output of patients, in particular by the process known as "thermo-dilution".
Ce procédé ne donne pas une information instantanée sur l'écoulement sanguin ni sur l'écoulement à partir du ventricule gauche, ce qui est très regrettable étant donné que les tonus veineux et sympathiques peuvent varier simultanément et de façon imprévisible. Par ailleurs, il est connu que les méthodes d'examen telles que la cathétérisation ne sont pas sans risque.This process does not give instant information on the blood flow or the flow from the left ventricle, which is very unfortunate since the venous and sympathetic tone can vary simultaneously and unpredictably. Furthermore, it is known that examination methods such as catheterization are not without risk.
La présente invention crée un nouveau procédé qui rend possible de connaître d'une manière instantanée des caractéristiques essentielles telles que le débit cardiaque, la vitesse d'écoulement du sang, en particulier dans l'aorte, l'accélération au début de la systole et, par conséquent, il devient possible d'intervenir de manière très rapide, ce qui est déterminant pour certains patients, notamment pour des patients ventilés mécaniquement et atteints d'affections graves.The present invention creates a new method which makes it possible to instantly know essential characteristics such as cardiac output, speed of flow of blood, in particular in the aorta, acceleration at the start of systole and , therefore, it becomes possible to intervene very quickly, which is decisive for some patients, especially for mechanically ventilated patients with serious conditions.
Conformément à l'invention, le procédé pour la détermination de caractéristiques cardio-vasculaires par voie externe, dans lequel on met en oeuvre l'effet Doppler, est caracté risé en ce qu'on détermine la section d'un vaisseau sanguin, en ce qu'on détermine la distance séparant une section sensiblement transversale du vaisseau d'une partie de la surface corporelle du patient, en ce qu'on émet à l'intérieur d'intervalles de temps réguliers des salves d'ultrasons, en ce qu'on recueille l'écho Doppler desdites salves à un intervalle de temps correspondant à la distance séparant le vaisseau de la partie de la surface corporelle du patient, en ce qu'on convertit les échos successivement recueillis en signaux Doppler directionnels, en ce qu'on convertit lesdits signaux Doppler directionnels en signaux numériques, en ce qu'on mémorise alternativement un nombre de signaux numériques qui est une puissance de 2 dans deux mémoires-tampons pendant des intervalles de temps d'échantillonnage sucessifs de courte durée, en ce qu'on traite alternativement par transformation de Fourier et en temps réel les signaux numériques provenant successivement de l'une et l'autre mémoirestampons pour établir un spectre de fréquences et. d'amplitudes correspondant à chaque temps d'échantillonnage, et en ce qu'on calcule la fréquence moyenneAccording to the invention, the method for determining cardiovascular characteristics externally, in which the Doppler effect is used, is characterized laughed at by determining the cross section of a blood vessel, by determining the distance between a substantially cross section of the blood vessel and part of the patient's body surface, by emitting inside regular time intervals of the ultrasonic bursts, in that the Doppler echo of said bursts is collected at a time interval corresponding to the distance separating the vessel from the part of the patient's body surface, in that '' the successively collected echoes are converted into directional Doppler signals, in that said directional Doppler signals are converted into digital signals, in that one alternately stores a number of digital signals which is a power of 2 in two buffers for short successive sampling time intervals, in that the digital signals coming successively from l are processed alternately by Fourier transformation and in real time 'and the other memory buffers to establish a frequency spectrum and. amplitudes corresponding to each sampling time, and in that the average frequency is calculated
Fmoy = ε (A2.F) ε A2 pour obtenir une courbe fonction du temps dont chaque période est l'image d'une systole.Fmoy = ε (A 2 .F) ε A 2 to obtain a curve as a function of time, each period of which is the image of a systole.
L'invention s'étend aussi à un dispositif pour la mise en oeuvre du procédé ci-dessus, dispositif qui par sa réalisation peut être réalisé sous un faible volume et à un prix peu élevé étant donné la spécificité de ses composants prévus pour remplir uniquement un nombre restreint de fonctions bien que dans des temps très brefs, et ainsi la miniaturisation qu'il est possible de réaliser du dispositif rend possible de le mettre en oeuvre même en dehors d'unités de soins intensifs. De plus, les informations que procure le dispositif peuvent être obtenues pour la plupart en lecture directe, par exemple sur un écran cathodique tout en permet tant, éventuellement, des enregistrements graphiques à des moments caractéristiques d'un traitement ou lors de l'évo¬lution brusque de l'état du patient.The invention also extends to a device for implementing the above method, device which by its realization can be produced in a small volume and at a low price given the specificity of its components intended to fill only a limited number of functions although in very short times, and thus the miniaturization that it is possible to carry out of the device makes it possible to implement it even outside intensive care units. In addition, the information provided by the device can be obtained for the most part in direct reading, for example on a cathode-ray screen while allowing as much, possibly, graphic recordings at characteristic moments of a treatment or during the sudden evolution of the patient's condition.
Conformément à cette seconde disposition de l'invention, le dispositif comporte un transducteur pour l'émission de salves d'ultrasons à intervalles de temps réguliers et pour la réception de l'écho Doppler en résultant,un circuit directionnel pour l'obtention de signaux Doppler directionnels, un convertisseur analogique numérique relié au circuit Doppler directionnel, deux mémoires-tampons reliées au convertisseur analogique numérique et recevant alternativement un nombre de points significatifs images du signal Doppler directionnel, un calculateur relié aux deux mémoires-tampons et traitant successivement les données illustratives des points emmagasinés dans lesdites mémoires-tampons pour la formation d'un spectre d'amplitudes et de fréquences illustrant respectivement la moitié de.s points significatifs emmagasinés à chaque fois dans chacune des mémoires-tampons, une première mémoire pour emmagasiner les amplitudes et fréquences caractéristiques du spectre et un ordinateur relié à ladite mémoire pour effectuer au moins le calcul ε(A2. F)According to this second arrangement of the invention, the device comprises a transducer for the emission of bursts of ultrasound at regular time intervals and for reception of the resulting Doppler echo, a directional circuit for obtaining signals Directional Doppler, an analog to digital converter connected to the directional Doppler circuit, two buffer memories connected to the analog to digital converter and receiving alternately a number of significant image points of the directional Doppler signal, a computer connected to the two buffers and successively processing the illustrative data points stored in said buffer memories for the formation of a spectrum of amplitudes and frequencies respectively illustrating half of the significant points stored each time in each of the buffer memories, a first memory for storing the amplitudes and frequencies spectrum characteristics and a computer connected to said memory to perform at least the calculation ε (A 2 . F)
Fmoy = ε A2 et transmettre le résultat dudit calcul à un moyen d'affichage.Fmoy = ε A 2 and transmit the result of said calculation to a display means.
L'invention trouve une application particulièrement importante dans l'établissement des caractéristiques cardiovasculaires, en particulier au niveau de l'aorte ascendante. Conformément à cette troisième disposition de l'invention, pour la détermination des caractéristiques cardio-vasculaires de l'aorte ascendante, le transducteur est disposé dans la fosse sus-sternale en arrière du manubrium en étant dirigé vers le bas pour intercepter un tronçon de l'aorte ascendante proche des valvules sigmoïdes. Diverses autres caractéristiques de l'invention ressortent d'ailleurs de la description détaillée qui suit.The invention finds a particularly important application in the establishment of cardiovascular characteristics, in particular at the level of the ascending aorta. According to this third arrangement of the invention, for the determination of the cardiovascular characteristics of the ascending aorta, the transducer is placed in the suprasternal fossa behind the manubrium, being directed downwards to intercept a section of the ascending aorta close to the sigmoid valves. Various other characteristics of the invention will also emerge from the detailed description which follows.
Une forme de réalisation de l'objet de l'invention est représentée, à titre d'exemple non limitatif, au dessin annexé.An embodiment of the object of the invention is shown, by way of nonlimiting example, in the accompanying drawing.
La fig. 1 est un schéma synoptique du dispositif pour la mise en oeuvre du procédé de détermination de caractéristiques cardio-vasculaires, objet de l'invention.Fig. 1 is a block diagram of the device for implementing the method for determining cardiovascular characteristics, object of the invention.
La fig. 2 est un schéma anatomique explicatif.Fig. 2 is an explanatory anatomical diagram.
La fig. 3 illustre deux courbes pour l'obtention d'un signal Doppler.Fig. 3 illustrates two curves for obtaining a Doppler signal.
La fig. 4 est un schéma illustrant une phase de traitement du procédé de l'invention.Fig. 4 is a diagram illustrating a processing phase of the method of the invention.
La fig. 5 illustre de façon schématique un spectre obtenu par transformation de Fourier à partir des signaux Doppler illustrés schématiquement à 1a fig. 3.Fig. 5 schematically illustrates a spectrum obtained by Fourier transformation from the Doppler signals illustrated schematically in FIG. 3.
La fig. 6 est une courbe illustrative de caractéristiques cardio-vasculaires obtenues selon l'invention en temps réel.Fig. 6 is an illustrative curve of cardiovascular characteristics obtained according to the invention in real time.
La fig. 7 est une courbe illustrant une représentation tridimensionnelle obtenue selon l'invention.Fig. 7 is a curve illustrating a three-dimensional representation obtained according to the invention.
La fig. 8 illustre la représentation, dite tridimensionnelle, obtenue des caractéristiques cardio-vasculaires déterminées selon l'invention à partir des courbes de 1a fig. 6.Fig. 8 illustrates the so-called three-dimensional representation obtained from the cardiovascular characteristics determined according to the invention from the curves of FIG. 6.
Les fig. 9 et 9a sont des représentations vectorielles illustrant la vitesse des globules sanguins dans un vaisseau pendant un temps d'échantillonnage défini en relation avec 1a fig. 3. Aux fig. 1 et 2, 1 désigne un transducteur pour l'émission de salves de signaux et la réception de signaux Doppler à travers une porte 2 menant à un circuit de traitement 3 de formation de signaux Doppler directionnels, c'est-à-dire tous positifs et compris par exemple entre 0 et 7 KHz.Figs. 9 and 9a are vector representations illustrating the speed of the blood cells in a vessel during a sampling time defined in relation to FIG. 3. In fig. 1 and 2, 1 designates a transducer for the emission of signal bursts and the reception of Doppler signals through a gate 2 leading to a processing circuit 3 for forming directional Doppler signals, that is to say all positive and for example between 0 and 7 KHz.
L'ensemble transducteur 1, porte 2 et circuit 3 est réglé comme l'illustre la fig. 3 pour obtenir tout d'abord des échantillons Doppler, c'est-à-dire que dans des intervalles de temps successifs T, T1 ... Tn, par exemple de 10 -4s, on émet tout d'abord une salve d'impulsions à haute fréquence par exemple à 4 MHz pendant un temps t.The transducer 1, door 2 and circuit 3 assembly is adjusted as illustrated in FIG. 3 to first obtain Doppler samples, that is to say that in successive time intervals T, T 1 ... T n , for example of 10 -4 s, first of all a burst of high frequency pulses for example at 4 MHz for a time t.
La fréquence des salves d'impulsions est choisie compte tenu de la vitesse approximative connue des globules sanguins, généralement comprise entre 0 et 150 cm/s dans l'aorte ascendante pendant une systole pour que le signal Doppler, c'est-à-dire la différence entre la fréquence émise et la fréquence reçue, soit une fréquence directionnelle comprise de préférence dans les fréquences audibles, par exemple entre 0 et 7 KHz, comme indiqué ci-dessus.The frequency of the bursts of pulses is chosen taking into account the approximate known speed of the blood cells, generally between 0 and 150 cm / s in the ascending aorta during a systole so that the Doppler signal, that is to say the difference between the transmitted frequency and the received frequency, ie a directional frequency preferably included in the audible frequencies, for example between 0 and 7 KHz, as indicated above.
Pour une détermination des caractéristiques cardio-vasculaires au niveau de l'aorte ascendante, on procède comme illustré à la fig. 2. A cette figure, 4 désigne le ventricule gauche du coeur, 5 les valvules sigmoïdes et 6 l'aorte ascendante.To determine the cardiovascular characteristics at the level of the ascending aorta, the procedure is as illustrated in FIG. 2. In this figure, 4 designates the left ventricle of the heart, 5 designates the sigmoid valves and 6 the ascending aorta.
Pour permettre de déterminer les caractéristiques notamment d'accélération, de vitesse et de débit dans la partie amont de l'aorte ascendante, on applique le transducteur 1 au niveau de la fosse sus-sternale 7, c'est-à-dire en arrière du manubrium 8 du patient et on maintient ladite tête 1a pour que son axe soit sensiblement vertical et dirigé vers le bas comme illustré par l'axe 9, afin que ledit axe soit approximativement concentrique à une coupe transversale 10 de la partie de l'aorte ascendante se trouvant à proximité des valvules sigmoïdes. Une étude anatomique peut d'ailleurs être effectuée pour chaque patient concerné avant l'examen au moyen d'une observation échographique permettant de situer la coupe 10 à environ 6 cm de la fosse sus-sternale 7 et, de même, la section aortique au niveau de la coupe 10 est normalement connue par des tables ou facilement déterminée par l'observation échographique.To allow the characteristics of acceleration, speed and flow in the upstream part of the ascending aorta to be determined, the transducer 1 is applied at the level of the suprasternal fossa 7, that is to say behind manubrium 8 of the patient and said head 1a is maintained so that its axis is substantially vertical and directed downward as illustrated by axis 9, so that said axis is approximately concentric to a cross section 10 of the part of the aorta ascending near the sigmoid valves. An anatomical study can moreover be carried out for each patient concerned before the examination by means of an ultrasound observation making it possible to locate the section 10 at approximately 6 cm from the suprasternal pit 7 and, likewise, the aortic section at the Cut level 10 is normally known from tables or easily determined by ultrasound observation.
Lorsque la position de la coupe 10 a été choisie correctement, on règle le temps t1 devant s'écouler entre la fin de la salve d'impulsions à haute fréquence émise pendant le temps t et l'ouverture de la porte 2 permettant de recevoir l'écho Doppler.When the position of the cut 10 has been chosen correctly, the time t 1 must be set to elapse between the end of the burst of high frequency pulses emitted during the time t and the opening of the door 2 making it possible to receive the Doppler echo.
Dans la pratique et dans l'exemple considéré de la coupe 10, le temps t1 est par exemple compris entre 60 et 80 μs , la porte 2 demeurant ensuite ouverte pendant un temps t 2 compris par exemple entre 1 et 3 μs. Ainsi que l'illustre la fig. 3, ledit temps t 2 représente le temps d'échantillonnage de la fréquence Doppler.In practice and in the example considered in section 10, the time t 1 is for example between 60 and 80 μs, the door 2 then remaining open for a time t 2 for example between 1 and 3 μs. As illustrated in fig. 3, said time t 2 represents the sampling time of the Doppler frequency.
Dans la pratique et compte tenu des indications numériques données dans ce qui précède, la coupe 10 présente un diamètre d'environ 3 cm et une épaisseur comprise entre 0,75 et 2,25 mm lorsque le niveau auquel l'écho doit être apprécié est distant de 4,5 à 6 cm de la partie émettrice réceptrice de la tête 1a du transducteur.In practice and taking into account the numerical indications given in the foregoing, the section 10 has a diameter of approximately 3 cm and a thickness of between 0.75 and 2.25 mm when the level at which the echo is to be appreciated is 4.5 to 6 cm away from the receiving transmitting part of the transducer head 1a.
Le signal Doppler directionnel provenant du circuit 3 est appliqué à un convertisseur analogique numérique 11 destiné à charger alternativement deux mémoires-tampons 12 et 13 qui sont reliées à un calculateur de traitement 14 dans lequel lesdites mémoires-tampons sont déchargées alternativement comme cela est illustré schématiquement à la fig. 4.The directional Doppler signal from circuit 3 is applied to an analog-to-digital converter 11 intended for alternately loading two buffer memories 12 and 13 which are connected to a processing computer 14 in which said buffer memories are alternately discharged as illustrated diagrammatically in fig. 4.
Dans le cas de l'exemple numérique énoncé dans ce qui précède, on réalise la conversion analogique numérique de façon que chaque mémoire-tampon 12, 13 reçoive successivement un nombre entier de points, qui soit une puissance de 2 et, de préférence, chaque mémoire reçoit 128 points constituant l'image numérique du signal Doppler correspondant à un laps de temps d'échantillonnage de 5 ms.In the case of the digital example stated in the foregoing, analog digital conversion is carried out so that each buffer memory 12, 13 receives successively a integer number of points, which is a power of 2 and, preferably, each memory receives 128 points constituting the digital image of the Doppler signal corresponding to a sampling time period of 5 ms.
Le calculateur de traitement 14 comporte un logiciel de calcul 14a faisant qu'il effectue une transformation de Fourier pour chacune des données rec;ues alternativement de l'une et l'autre mémoires dans des laps de temps d'échantillonnage successifs de 5 ms.The processing calculator 14 comprises a calculation software 14a causing it to perform a Fourier transformation for each of the data received alternately from one and the other memories in successive sampling time periods of 5 ms.
La fig. 5 montre que le calculateur de traitement 14 établit pendant chaque laps de temps de 5 ms un spectre de 64 valeurs de fréquence F et de 64 valeurs d'amplitude A.Fig. 5 shows that the processing computer 14 establishes, during each 5 ms period of time, a spectrum of 64 values of frequency F and 64 values of amplitude A.
Les valeurs des fréquences et des amplitudes ainsi calculées pendant chaque laps de temps de 5 ms sont stockées dans des mémoires 15 d'amplitudes et de fréquences reliées à un ordinateur 16 (fig. 1) qui, dans l'exemple décrit dans ce qui suit, est conçu pour exécuter deux types de calculs et qui peut, par conséquent, être constitué sous la forme d'une unité spécifique à ces seuls types de calculs, ce qui permet de le réaliser sous forme réduite et à relativement bon marché.The values of the frequencies and the amplitudes thus calculated during each lapse of time of 5 ms are stored in memories 15 of amplitudes and frequencies connected to a computer 16 (fig. 1) which, in the example described in the following , is designed to perform two types of calculations and which can therefore be constituted in the form of a unit specific to these only types of calculations, which allows it to be performed in reduced form and relatively inexpensively.
L'ordinateur 16 recevant les données des mémoires 15 effectue à partir de chaque spectre conforme à celui de la fig. 5 un calcul de fréquence moyenne en temps réel, c'est-à-dire au fur et à mesure de l'établissement de chaque spectre.The computer 16 receiving the data from the memories 15 performs from each spectrum conforming to that of FIG. 5 an average frequency calculation in real time, that is to say as each spectrum is established.
Le calcul des fréquences moyennes correspond à la formule ε (A2.F)The calculation of the average frequencies corresponds to the formula ε (A 2 .F)
Fmoy = ε A2 Les résultats du calcul ci-dessus permettent de tracer une courbe de fréquences moyennes en fonction du temps, c'est- à-dire une courbe qui est une image dans le temps notamment de l'accélération et de la vitesse du sang au cours de chaque systole au niveau de la coupe 10 de la fig. 2.Fmoy = ε A 2 The results of the calculation above make it possible to draw a curve of average frequencies as a function of time, that is to say a curve which is an image in time in particular of the acceleration and the speed of the blood during each systole at the level of section 10 of FIG. 2.
Ce qui précède montre que le front avant de chaque impulsion I de la courbe de la fig. 6 correspond à l'accélération que subit le sang au début de la systole, le front avant de ladite courbe étant ainsi une illustration très importante de l'état cardiaque puisque l'accélération que subit le sang dans l'aorte ascendante à proximité des valvules sigmoïdes est une image de la contractilité du muscle cardiaque.The above shows that the front edge of each pulse I of the curve of FIG. 6 corresponds to the acceleration that the blood undergoes at the start of the systole, the front edge of said curve thus being a very important illustration of the cardiac state since the acceleration that the blood undergoes in the ascending aorta near the valves sigmoid is an image of the contractility of the heart muscle.
La surface de chaque impulsion I correspond par ailleurs au volume du sang éjecté pendant la systole, ce volume pouvant ainsi être facilement calculé par l'ordinateur 16 qui n'a à effectuer que l'intégrale de chaque impulsion.The area of each pulse I also corresponds to the volume of blood ejected during systole, this volume can thus be easily calculated by the computer 16 which only has to carry out the integral of each pulse.
Etant donné que la section de l'aorte est également connue comme cela est expliqué dans ce qui précède, le produit de la vitesse par cette section peut également être exécuté facilement par l'ordinateur pour connaître le débit sanguin à chaque systole.Since the section of the aorta is also known as explained in the foregoing, the product of the velocity by this section can also be easily executed by the computer to know the blood flow to each systole.
La courbe de la fig. 6 étant une courbe de fréquences en fonction du temps et cette courbe délimitant avec précision les sytoles et diastoles successives, les durées de ces dernières sont également déterminées d'une manière simple.The curve of fig. 6 being a frequency curve as a function of time and this curve delimiting with precision the successive sytoles and diastoles, the durations of the latter are also determined in a simple manner.
Comme l'illustre la fig. 1, l'ordinateur 16 est normalement relié à un écran 17 permettant d'afficher en permanence les caractéristiques calculées par l'ordinateur.As illustrated in fig. 1, the computer 16 is normally connected to a screen 17 making it possible to permanently display the characteristics calculated by the computer.
Un clavier 18 est associé à l'ordinateur 16 pour permettre à l'opérateur d'emmagasiner en mémoire pendant un temps plus ou moins long, par exemple 5 à 7 secondes, les coordonnées de la courbe de la fig. 6 et de permettre ainsi ensuite de faire un tracé au moyen d'un scripteur 19 des données de la courbe de la fig. 6 qui ont été gelées dans une mémoire pendant le temps choisi ci-dessus. On voit par ce qui précède que, par les moyens décrits, l'invention permet, par exemple à chaque période cardiaque, de connaître le volume sanguin éjecté au cours de la systole, de connaître le temps d'éjection, la vitesse sanguine maximale, l'accélération sanguine maximale et le débit cardiaque, résultats qui permettent à leur tout d'apprécier l'état cardio-vasculaire et notamment les caractéristiques de contractilité du muscle.A keyboard 18 is associated with the computer 16 to allow the operator to store in memory for a more or less long time, for example 5 to 7 seconds, the coordinates of the curve of FIG. 6 and thus allow then to make a plot by means of a writer 19 of the data of the curve of FIG. 6 which have been frozen in memory for the time selected above. It can be seen from the above that, by the means described, the invention makes it possible, for example at each cardiac period, to know the blood volume ejected during systole, to know the ejection time, the maximum blood speed, maximum blood acceleration and cardiac output, results which allow them to appreciate the cardiovascular state and in particular the contractility characteristics of the muscle.
Le procédé de l'invention s'étend également à la détermination et à la visualisation des différences de vitesse des glovules sanguins dans le vaisseau étudié en faisant apparaître les résultats obtenus sous la forme d'un tracé tri-dimensionnel qui apparaît ainsi à la manière d'une représentation en relief. Pour cela et comme le montre la fig. 7, les spectres d'amplitudes et de fréquences de la mémoire 15 sont transférés dans l'ordinateur 16 pour y être stockés et traités en temps différés, c'est-à-dire que la succession de données d'amplitudes et de fréquences permet à partir de la courbe selon la fig. 5 de tracer à l'issue de chaque temps d'échantillonnage de 5 ms une premier enveloppe du spectre comme cela est illustré par la courbe E1 de la fig. 7.The method of the invention also extends to the determination and the visualization of the differences in speed of the blood glovules in the vessel studied by showing the results obtained in the form of a three-dimensional plot which thus appears in the manner a relief representation. For this and as shown in fig. 7, the amplitude and frequency spectra of the memory 15 are transferred to the computer 16 to be stored and processed there in deferred time, that is to say that the succession of amplitude and frequency data allows from the curve according to fig. 5 to trace at the end of each sampling time of 5 ms a first envelope of the spectrum as illustrated by the curve E 1 of FIG. 7.
L'ordinateur 16 est programmé pour calculer puis tracer ensuite l ' enveloppe E2 du spectre du second temps d ' échantillonnage de 5 ms. Le traçage de la courbe E2 et des suivantes s'effectue selon des coordonnées décalées dans le temps de mesures régulières, images du temps d'échantillonnage de 5 ms comme indiqué à la fig. 7. Le calcul du tracé des courbes E1 , E2 ... En des enveloppes des spectres successifs est réalisé comme le montre la fig. 7 pour que seules apparaissent les parties des enveloppes non cachées par les enveloppes précédentes.The computer 16 is programmed to calculate and then trace the envelope E 2 of the spectrum of the second sampling time of 5 ms. The plotting of the curve E 2 and of the following ones is carried out according to coordinates shifted in the time of regular measurements, images of the sampling time of 5 ms as indicated in fig. 7. The calculation of the plot of the curves E 1 , E 2 ... E n of the envelopes of the successive spectra is carried out as shown in FIG. 7 so that only the parts of the envelopes not hidden by the preceding envelopes appear.
La représentation tridimensionnelle qui est ainsi obtenue et qui est illustrée à la fig. 8 de façon à correspondre au temps T de la fig. 6 fait apparaître de cette manière, suivant l'axe des amplitudes les vitesses vectoreilles, illustrées aux fig. 9 et 9a, des globules sanguins entre les parois aortiques 20 au cours des trois systoles illustrées dans ledit temps T, les mesures selon l'axe des amplitudes A correspondant aux informations données dans la représentation antérieurement connue des variations dans l'échelle des gris.The three-dimensional representation which is thus obtained and which is illustrated in FIG. 8 so as to correspond to the time T of FIG. 6 makes it appear in this way, along the amplitude axis the vector velocities, illustrated in figs. 9 and 9a, blood cells between the aortic walls 20 during the three systoles illustrated in said time T, the measurements along the axis of the amplitudes A corresponding to the information given in the previously known representation of the variations in the gray scale.
De la même façon qu'exposé dans ce qui précède, le tracé tridimensionnel décrit est obtenu en agissant sur le clavier 18 de l'ordinateur 16 pour geler dans la mémoire principale de celui-ci les données des spectres successifs à 64 amplitudes et 64 fréquences des mémoires 15 pendant un temps, par exemple d'environ 10 secondes ou davantage, pour permettre ensuite et en temps différé le traçage tridimensionnel sur un laps de temps significatif correspondant par exemple à un cycle respiratoire, ce qui permet ensuite à l'observateur d'apprécier les cycles cardiaques compte tenu des interférences produites sur la circulation aortique dans les cours des cycles respiratoires.In the same way as explained in the foregoing, the three-dimensional trace described is obtained by acting on the keyboard 18 of the computer 16 to freeze in the main memory of the latter the data of the successive spectra at 64 amplitudes and 64 frequencies. memories 15 for a time, for example of about 10 seconds or more, to then allow and in delayed time the three-dimensional tracing over a significant period of time corresponding for example to a respiratory cycle, which then allows the observer to '' appreciate the cardiac cycles taking into account the interferences produced on the aortic circulation in the course of the respiratory cycles.
L'invention n'est pas limitée à l'exemple de réalisation représenté et décrit en détail, car diverses modifications peuvent y être apportées sans sortir de son cadre. En particulier, ce qui est décrit dans ce qui précède peut être mis en oeuvre pour la détermination des caractéristiques vasculaires d'autres vaisseaux, notamment d'autres artères. The invention is not limited to the embodiment shown and described in detail, because various modifications can be made without departing from its scope. In particular, what is described in the foregoing can be used for the determination of the vascular characteristics of other vessels, in particular other arteries.

Claims

RevendicationsClaims
1 - Procédé pour la détermination de caractéristiques cardiovasculaires par voie externe dans lequel on met en oeuvre l'effet Doppler, caractérisé en ce qu'on détermine la section d'un vaisseau sanguin, en ce qu'on détermine la distance séparant une section sensiblement transversale du vaisseau d'une partie de la surface corporelle du patient, en ce qu'on émet à l'intérieur d'intervalles de temps réguliers des salves d'ultrasons, en ce qu'on recueille l'écho Doppler desdites salves à un intervalle de temps correspondant à la distance séparant la section transversale choisie du vaisseau de la partie de la surface corporelle du patient, en ce qu'on convertit les échos successivement recueillis en signaux Doppler directionnels, en ce qu'on convertit lesdits signaux Doppler directionnels en signaux numériques, en ce qu'on mémorise alternativement un nombre de signaux numériques qui est une puissance de 2 pendant des intervalles de temps d'échantillonnage successifs de courte durée, en ce qu'on traite alternativement par transformation de1 - Process for the determination of cardiovascular characteristics externally in which the Doppler effect is implemented, characterized in that the section of a blood vessel is determined, in that the distance separating a section substantially is determined transverse of the vessel from a part of the patient's body surface, in that it emits within regular time intervals bursts of ultrasound, in that it collects the Doppler echo of said bursts at a time interval corresponding to the distance separating the selected cross-section of the vessel from the part of the patient's body surface, in that the successively collected echoes are converted into directional Doppler signals, in that said directional Doppler signals are converted into digital signals, in that alternately stores a number of digital signals which is a power of 2 during successive sampling time intervals of short-term, in that it is treated alternately by transformation of
Fourier et en temps réel les signaux numériques mémorisés pour établir un spectre de fréquences et d'amplitudes correspondant à chaque temps d'échantillonnage, et en ce qu'on calcule la fréquence moyenneFourier and in real time the digital signals stored to establish a spectrum of frequencies and amplitudes corresponding to each sampling time, and in that the average frequency is calculated
Fmoy = ε(A2. F) ε A2 pour obtenir une courbe fonction du temps dont chaque alternance positive est l'image d'une systole.Fmoy = ε (A 2. F) ε A 2 to obtain a time-dependent curve, each positive alternation of which is the image of a systole.
2 - Procédé selon la revendication 1, caractérisé en ce qu'on mémorise pendant un temps significatif, de l'ordre de plusieurs secondes, les points de la courbe de fréquence moyenne, en ce qu'on trace la courbe obtenue à partir desdits points, en ce qu'on intègre la surface les alternances successives de la courbe pour déterminer le volume sanguin, en ce qu'on multiplie ladite vitesse par la section du vaisseau examiné pour faire apparaître le débit cardiaque soit au cours de chaque systole successive/ soit à l'issue d'un autre laps de temps choisi et en ce qu'on lit la pente du front avant des alternances pour déterminer l'accélération sanguine, reflet de la contractilité cardiaque.2 - Method according to claim 1, characterized in that it stores for a significant time, of the order of several seconds, the points of the average frequency curve, in that we trace the curve obtained from said points , in that one integrates the surface the successive alternations of the curve to determine the blood volume, in that one multiplies said speed by the section of the vessel examined to reveal the cardiac output either during each successive systole / or at the end of another chosen period of time and in that the slope of the forehead is read before the alternations to determine the blood acceleration, a reflection of the cardiac contractility.
3 - Procédé suivant l'une des revendications 1 et 2, caractérisé en ce qu'on mémorise les spectres successifs des amplitudes et des fréquences obtenus au cours de chaque temps d'échantillonnage, en ce qu'on détermine les envelop- pes des spectres successifs et en ce qu'on trace les enveloppes des spectres successifs de manière décalée le long de l'axe des temps à des intervalles correspondant au temps d'échantillonnage de chacun d'eux et de façon que seule la partie visible de l'enveloppe d'un nouveau spectre reste apparente par rapport à l'enveloppe des spectres précédents, de sorte qu'on obtient une représentation tridimensionnelle pour chaque systole en faisant apparaître la durée, le temps d'éjection, la vitesse sanguine, l'accélération sanguine et la différences de vitesses des globules sanguins dans la partie examinée du vaisseau.3 - Method according to one of claims 1 and 2, characterized in that the successive spectra of the amplitudes and frequencies obtained during each sampling time are memorized, in that the envelopes of the spectra are determined successive and in that the envelopes of the successive spectra are drawn offset along the time axis at intervals corresponding to the sampling time of each of them and so that only the visible part of the envelope of a new spectrum remains apparent with respect to the envelope of the previous spectra, so that a three-dimensional representation is obtained for each systole by showing the duration, the ejection time, the blood speed, the blood acceleration and differences in the speed of blood cells in the examined part of the vessel.
4 - Dispositif pour la mise en oeuvre du procédé selon l'une des revendications 1 à 3, caractérisé en ce qu'il comporte un transducteur (1) pour l'émission de salves d'ultrasons à intervalles de temps réguliers et pour la réception d'échos Doppler à fréquence audible en résultant, un circuit directionnel pour l'obtention de signaux Doppler directionnels, un convertisseur analogique numérique relié au circuit Doppler directionnel, deux mémoires (12, 13) reliées au convertisseur analogique numérique et recevant alternativement un nombre de points significatifs images du signal Doppler directionnel, un calculateur relié aux deux mémoires- tampons et traitant successivement les données illustratives des points emmagasinés dans lesdites mémoires-tampons pour la formation d'un spectre d'amplitudes et de fréquences illustrant respectivement la moitié des points significatifs emmagasinés à chaque fois dans chacune des mémoires-tampons, une première mémoire (15) pour emmagasiner les amplitudes et fréquences caractéristiques du spectre et un ordinateur (16) relié à ladite mémoire (15) pour effectuer au moins le calcul4 - Device for implementing the method according to one of claims 1 to 3, characterized in that it comprises a transducer (1) for the emission of bursts of ultrasound at regular time intervals and for reception resulting audible frequency Doppler echoes, a directional circuit for obtaining directional Doppler signals, an analog to digital converter connected to the directional Doppler circuit, two memories (12, 13) connected to the analog to digital converter and alternately receiving a number of significant points images of the directional Doppler signal, a computer connected to the two buffer memories and successively processing the illustrative data of the points stored in said buffer memories for the formation of a spectrum of amplitudes and frequencies respectively illustrating half of the significant points stored each time in each of the buffer memories, a first memory (15) in. ur store the amplitudes and characteristic frequencies of the spectrum and a computer (16) connected to said memory (15) to perform at least the calculation
Fmoy = ε (A2.F) ε A2 et transmettre le résultat dudit calcul à un moyen d'affichageFmoy = ε (A 2 .F) ε A 2 and transmit the result of said calculation to a display means
(17).(17).
5 - Dispositif suivant la revendication 4, caractérisé en ce que l'ordinateur (16) comporte un clavier (18) pour la commande du stockage d'un nombre déterminé de données successives correspondant à la fréquence moyenne5 - Device according to claim 4, characterized in that the computer (16) comprises a keyboard (18) for controlling the storage of a determined number of successive data corresponding to the average frequency
Fmoy = ε(A2.F) εA2 pendant une durée significative de l'ordre de 5 à 10 s et des moyens de traçage (19) d'une courbe à partir desdites fréquences Fmoy calculées.Fmoy = ε (A 2 .F) εA 2 for a significant duration of the order of 5 to 10 s and means for plotting (19) a curve from said frequencies Fmoy calculated.
6 - Dispositif suivant l'une des revendications 4 et 5, caractérisé par des moyens pour mémoriser dans l'ordinateur les spectres successifs obtenus au cours des temps d'échantillonnage successifs correspondant au nombre de points emmagasinés alternativement dans chacune des mémoires (12, 13), par des moyens pour déterminer l'enveloppe (E1, E2 ... En) des spectres successifs et par des moyens pour tracer la partie visible des enveloppes (E2 ... En) successives à des intervalles distants les uns des autres pour faire apparaître une courbe tridimensionnelle.6 - Device according to one of claims 4 and 5, characterized by means for storing in the computer the successive spectra obtained during the successive sampling times corresponding to the number of points stored alternately in each of the memories (12, 13 ), by means for determining the envelope (E 1 , E 2 ... E n ) of the successive spectra and by means for drawing the visible part of the envelopes (E 2 ... E n ) successively at distant intervals from each other to reveal a three-dimensional curve.
7 - Dispositif suivant l'une des revendications 4 à 6, caractérisé en ce que le convertisseur analogique numérique (11) est relié à deux mémoires-tampons emmagasinant chacune successivement 128 points caractéristiques en un laps de temps d'échantillonnage de 5 ms.7 - Device according to one of claims 4 to 6, characterized in that the analog digital converter (11) is connected to two buffer memories each storing successively 128 characteristic points in a sampling time of 5 ms.
8 - Dispositif suivant l'une des revendications 4 à 7, caractérisé en ce que le calculateur (14) relié aux deux mémoirestampons (12, 13) est piloté pour effectuer à partir des 128 points reçus chaque 5 ms successivement de l'une et l'autre mémoires-tampons un spectre de 64 amplitudes et8 - Device according to one of claims 4 to 7, characterized in that the computer (14) connected to the two buffer memories (12, 13) is controlled to perform from 128 points received each 5 ms successively from both buffers a spectrum of 64 amplitudes and
64 fréquences à partir desquelles est calculée la fréquence64 frequencies from which the frequency is calculated
Fmoy = ε (A2.F) ε A2 Fmoy = ε (A 2 .F) ε A 2
9 - Dispositif suivant l ' une des revendications 4 à 8 , caractérisé en ce que le tracé des enveloppes successives (E1,9 - Device according to one of claims 4 to 8, characterized in that the layout of the successive envelopes (E 1 ,
E2 ... En) est effectué tous les 5 ms.E2 ... E n ) is performed every 5 ms.
10 - Dispositif suivant l'une des revendications 4 à 9,caractérisé par une porte réglable prévue dans la tête (1a) du transducteur (1) pour régler le laps de temps ( t1 ) s'écoclant entre la fin de l'émission de la salve d'ultrasons et le début de la réception de l'écho Doppler (t2) .10 - Device according to one of claims 4 to 9, characterized by an adjustable door provided in the head (1a) of the transducer (1) for adjusting the time lapse (t 1 ) flowing between the end of the emission of the ultrasonic burst and the start of reception of the Doppler echo (t 2 ).
11 - L'application du procédé et du dispositif de l'une des revendications 1 à 9 à la détermination des caractéristiques cardio-vasculaires de l'aorte ascendante dans laquelle le transducteur est disposé contre la fosse sussternale en arrière du manubrium en étant dirigé vers le bas pour intercepter un tronçon de l'aorte ascendante proche des valvules sigmoïdes.11 - The application of the method and the device of one of claims 1 to 9 to the determination of the cardiovascular characteristics of the ascending aorta in which the transducer is disposed against the sussternal fossa behind the manubrium being directed towards the bottom to intercept a section of the ascending aorta close to the sigmoid valves.
12 - L'application de la revendication 11 dans laquelle la salve d'ultrasons est émise à 4 MHz pendant un temps t, la porte (2) étant réglée pour que l'écho Doppler soit reçu un temps t1 égal à 60 à 80 μs après la fin de la salve d'impulsions à 4 MHz.12 - The application of claim 11 in which the burst of ultrasound is emitted at 4 MHz for a time t, the gate (2) being adjusted so that the Doppler echo is received a time t 1 equal to 60 to 80 μs after the end of the 4 MHz pulse burst.
13 - Application des revendications 11 et 12, caractérisée en ce qu ' une salve d'ultrasons et un écho Doppler sont respectivement émis et reçus à l'intérieur d'intervalles de temps réguliers de l'ordre de 10 -4s. 13 - Application of claims 11 and 12, characterized in that a burst of ultrasound and a Doppler echo are respectively transmitted and received within regular time intervals of the order of 10 -4 s.
EP19850906077 1984-12-07 1985-12-06 Method and device for determining the cardiovasculary characteristics by external process and application thereof to cardiopathies Pending EP0205487A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8418779A FR2574280B1 (en) 1984-12-07 1984-12-07 METHOD AND DEVICE FOR DETERMINING CARDIOVASCULAR CHARACTERISTICS BY EXTERNAL ROUTE AND THEIR APPLICATION TO HEART DISEASE
FR8418779 1984-12-07

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JP (1) JPS62501269A (en)
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FR2600778B1 (en) * 1986-06-27 1988-09-02 Trt Telecom Radio Electr RADAR DEVICE FOR MEASURING THE DISTANCE FROM A SURFACE
US5085220A (en) * 1989-10-05 1992-02-04 Spacelabs, Inc. Doppler flow sensing device and method for its use
GB9112854D0 (en) * 1991-06-14 1991-07-31 Skidmore Robert Flowmeters
US5285788A (en) * 1992-10-16 1994-02-15 Acuson Corporation Ultrasonic tissue imaging method and apparatus with doppler velocity and acceleration processing
AUPQ508300A0 (en) * 2000-01-14 2000-02-10 Kyushu University A cardiac valve movement measuring device
GB0001773D0 (en) * 2000-01-27 2000-03-22 Deltex Guernsey Ltd Improvements in or relating to cardiac function monitors
CN108037494B (en) * 2017-12-05 2021-05-14 大连大学 Radar target parameter estimation method under impulse noise environment
CN110221279B (en) * 2019-06-21 2023-03-03 瑞纳智能设备股份有限公司 Automatic detection system and detection method for ultrasonic transducer

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US4257278A (en) * 1979-08-24 1981-03-24 General Electric Company Quantitative volume blood flow measurement by an ultrasound imaging system featuring a Doppler modality
US4378022A (en) * 1981-01-15 1983-03-29 California Institute Of Technology Energy-frequency-time heart sound analysis
US4476874A (en) * 1982-06-01 1984-10-16 Sri International Ultrasonic imaging with volume flow measuring method and apparatus

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FR2574280A1 (en) 1986-06-13
JPS62501269A (en) 1987-05-21
FR2574280B1 (en) 1988-11-25
WO1986003593A1 (en) 1986-06-19

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