EP1026989A1 - Diagnostic non invasif en temps reel de la migraine - Google Patents

Diagnostic non invasif en temps reel de la migraine

Info

Publication number
EP1026989A1
EP1026989A1 EP97918333A EP97918333A EP1026989A1 EP 1026989 A1 EP1026989 A1 EP 1026989A1 EP 97918333 A EP97918333 A EP 97918333A EP 97918333 A EP97918333 A EP 97918333A EP 1026989 A1 EP1026989 A1 EP 1026989A1
Authority
EP
European Patent Office
Prior art keywords
blood flow
flow rate
ultrasound waves
brain
intracranial
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.)
Withdrawn
Application number
EP97918333A
Other languages
German (de)
English (en)
Other versions
EP1026989A4 (fr
Inventor
David Michaeli
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.)
Inta Medics Ltd
Original Assignee
Inta Medics Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from IL11962396A external-priority patent/IL119623A0/xx
Application filed by Inta Medics Ltd filed Critical Inta Medics Ltd
Publication of EP1026989A1 publication Critical patent/EP1026989A1/fr
Publication of EP1026989A4 publication Critical patent/EP1026989A4/fr
Withdrawn legal-status Critical Current

Links

Definitions

  • the present invention relates generally to diagnosis and study of migraine by observation of variations in the blood flow in the brain.
  • migraine sufferers do not turn to neurology departments of medical institutions, but rather turn to their family doctor for prescription on an ad hoc basis.
  • Migraine is known to be diagnosed via clinical examinations and non-objective means.
  • One objective finding known to be closely associated with migraine is variation, contraction or dilation, of blood vessels in the brain.
  • patients are sent for MRI or CT examinations — examinations that are very costly and that often involve a long waiting time. This, of course, causes inconvenience to the patient, who also has to travel to the medical centers that have these devices, which, in many cases, are far from the patient's home.
  • Isotope Diagnosis Isotope Diagnosis
  • TCD Transcranial Dopplerography
  • Transcranial Dopplerography is noninvasive and does give real-time measurement, but it does not measure the volumetric velocity of the blood flow and does not give precise measurement of the contraction or dilation of blood vessels in the brain. It is therefore not useful for diagnosis of migraine.
  • This imprecision results from the fact that TCD can only be used to observe a sector or large area in the brain, instead of a localized point.
  • TCD uses ultrasound waves at a frequency of 2 MHz, which, for an estimated 15 ⁇ 40% of the population [DR. MICHAELI: REFERENCE, PLEASE.], do not actually reach the interior of the cranium, because of high attenuation of the ultrasound waves in the bone tissue of the cranium.
  • the acoustic reflections detected are only from the magistrial and proximal blood vessels.
  • this method also detects reflections from the brain and from other, non-cranial, blood vessels. The result is a noisy signal which does not allow precise determination of the depth of the measurement point. This does not allow measurement of individual blood vessels or their blood flow with any precision.
  • Use of ultrasound technology as a diagnostic tool is discussed, inter alia, in the book entitled “Textbook of Diagnostic Ultrasonography,” 4 th edition, by Mosby, pages 682-686.
  • the present invention seeks to provide a method and device which facilitates observation in real-time of migraine activity. It is sought to accomplish this by detecting variations in cranial blood flow and observing the contraction or dilation of blood vessels in the brain.
  • the technique used in the present invention is non-invasive and is based on objective measurement.
  • the present invention is based on ultrasound technology, with no injection of contrast- enhancing or any other substances into the bloodstream.
  • the measurement results are displayed immediately, in real-time, on a computer display terminal, which allows immediate detection of changes in blood flow at a precisely defined location (i.e., position and depth) in blood vessels in the brain.
  • the time for the measurement with the present invention is negligible compared to the time required for the currently accepted methods of measurement. Measurement with the present invention is also less costly than currently accepted methods of measurement.
  • the present invention utilizes innovative application of ultrasound technology and the known reaction of different tissues to ultrasound waves for the diagnosis of changes in the system of blood vessels in the cranium (pathophysiology) in patients suffering from migraines.
  • the present invention is based on analysis of reflected ultrasound pulses from the different structures in the intracranial space (i.e., brain, ventricles, vasales, and cysterns), their recording on magnetic media, and their immediate presentation, in real-time, on a computer display terminal.
  • a method of real-time determination of variations in effective diameter of cranial blood vessels, thereby to provide an indication of migraine activity which includes determining the blood flow rate to the brain of a subject; determining the intracranial blood flow rate in selected blood vessels; and comparing the intracranial blood flow rate with the determined blood flow rate to the brain thereby to determine a change in the intracranial blood flow rate relative to the blood flow rate to the brain, indicating a corresponding change in the effective diameter of the preselected blood vessel.
  • the method also includes the step, between the steps of determining the blood flow rate and determining the intracranial blood flow rate, of observing the pulsatile variations in the intracranial blood flow in selected blood vessels in real time, and further includes the step, between the steps of determining the intracranial blood flow rate and comparing, of analyzing the pulsatile variations in the intracranial blood flow in selected blood vessels thereby to determine changes in the effective diameter of the selected blood vessel.
  • the steps of observing the pulsatile variations in the intracranial blood flow in selected blood vessels includes the sub-steps of exposing the head of the subject to pulses of ultrasound waves in a frequency waveband selected so as to not to be substantially attenuated by bone tissue, and such that the ultrasound energy is reflected; and detecting ultrasound waves reflected from the selected blood vessels; and the step of determining intracranial blood flow rate further includes comparing reflected ultrasound waves with transmitted ultrasound waves in real-time, thereby to reveal pulsatile variations in the intracranial blood flow in selected blood vessels and to determine a rate of intracranial blood flow in the selected blood vessels.
  • the step of determining the blood flow rate to the brain includes detection of a reference pulse at a predetermined location upstream in the blood stream from the brain in synchronization with the step of observing pulsatile variations in the intracranial blood flow.
  • this is performed by employing ECG in synchronization with the step of dete ⁇ nining the intracranial blood flow rate
  • the step of exposing the head of the subject to pulses of ultrasound waves includes emitting ultrasound waves in the frequency range 0.5-3.0 MHz, but preferably in the range 0.8-1.2 MHz, and having a output intensity in the range 100-300 mW/cm 2 , but, in any case, not greater than 300 mW/cm 2 .
  • Figure 1 is a block diagram of a system for observing variations in the blood flow in the brain, constructed and operative in accordance with an embodiment of the present invention.
  • Figure 2 is an illustration of a main unit of the system of the present invention, showing the primary components or modules of the system in their housing or cage.
  • FIG 3-A is a more detailed block diagram of the modules contained in the cage in Figure 2.
  • FIG. 3-B is a more detailed block diagram of the circuits performing the primary ultrasound signal processing functions, the Echo Encephalogram (ECHO-EG) and the Echo PulsoGram (EPG).
  • ECHO-EG Echo Encephalogram
  • EPG Echo PulsoGram
  • Figure 4-A is a graphical data output display of the present embodiment of the system of the invention, obtained from a healthy subject.
  • Figures 4-B and 4-C are graphical data output displays of the present embodiment of the system of the invention, obtained from a subject suffering from migraine, for the right and left hemispheres of the brain, respectively.
  • the present invention provides a system, referenced generally 100, for providing an indication of the status of cranial blood vessels, dilation or contraction, as part of the chain of causes of migraine.
  • a system referenced generally 100, for providing an indication of the status of cranial blood vessels, dilation or contraction, as part of the chain of causes of migraine.
  • the present invention allows determination of whether there are local increases or decreases in rate of blood flow in the brain. This indicates whether selected blood vessels in the brain are dilated or contracted, which is known to be associated with migraine activity. The determination is based on the measurement of changes in the blood vessels in the brain, which indicate deviations from known normal rate of blood flow to the brain.
  • the present invention includes a number of factors to overcome these problems. These include using ultrasound waves transmitted in pulses at a preferred frequency of 1.0 ⁇ 0.2 MHz, which allows use of Ultrasound power preferably of 250 ⁇ 50 mW/cm 2 .
  • the present invention includes the analysis and interpretation of the reflected pulses of ultrasound waves detected from those transmitted to the brain in a manner that provides both mean and real-time measurement of the rate of blood flow in the brain at selected locations.
  • the system 100 of the present invention includes an Ultrasound probe 101, a computer 107 having an .Analog to Digital (A/D) converter 106, and an Ultrasound Signal controller and processor, referenced generally 112, a Gating circuit 104, and a Electrocardiograph (ECG) 105, connected to the A/D converter 106.
  • the system includes a suitable low- voltage power supply 109 to provide power to these circuits and a high- voltage power supply 108 to supply the Ultrasound Transmitter 113 which drives the probe 101.
  • a suitable display terminal 110 and printer 111 and appropriate software, as described below m conjunction with the description of computer 107.
  • Probe 101 may be any suitable ultrasound probe for emission and detection of ultrasound waves of a frequency range of 0.5-3.0 MHz, but preferably 1.0 ⁇ 0.2 MHz, and having a output intensity in the range of 100-300 mW/cm2, but preferably 250 ⁇ 50 mW/cm2, and in any case no greater than 300 mW/cm2.
  • Computer 107 is provided for control of the measurement and analysis of the resulting data and may be based on any suitable microprocessor such as a 486 (or higher)-based PC.
  • the computer 107 includes a program written to perform data collection, display, and analysis.
  • the data collection functions, which control the measurement process could be performed by a suitable dedicated microprocessor included in the Ultrasound Signal controller 112.
  • the display and analysis program is built from two modules. A first program module displays the digital signals coming from the A/D Converter 106 which originate in the ECHO- EG 102, EPG 103, and ECG 105 circuits. A second program module allows analysis of the pulses at the specific measurement point by means of the signals from the EPG 103 and the Gating circuit 104.
  • the Ultrasound Signal controller and processor 112 is responsible for generation of pulses of ultrasound waves with a frequency of 1.0 ⁇ 0.2 MHz, by probe 101, detection of the reflected waves or echoes, also by probe 101, and processing of the signals so detected.
  • the reflected waves are received as one-dimensional Echo Encephalogram (ECHO-EG) 102 signals.
  • ECHO-EG Echo Encephalogram
  • this Ultrasound Signal controller and processor 112 operates as follows:
  • the Ultrasound Transmitter 113 powered by the high-voltage power supply 108, receives a Start signal from the computer 107 via the A/D and the Gates 104. In response, it generates a series of Ultrasound pulses in the probe 101.
  • the probe which is typically placed at a location of interest on the head of the subject being examined, transmits the Ultrasound pulses into the head and brain of the subject and detects the Ultrasound energy reflected from various locations within the head and brain of the subject.
  • the reflected signal from the brain is passed by the probe 101 to the Echo Encephalogram (ECHO-EG) 102 block of the Ultrasound Signal controller and processor 112.
  • ECHO-EG Echo Encephalogram
  • the reflected Ultrasound pulses are received as one-dimensional digital Echo Encephalogram (ECHO-EG) 102 signals, which provides a representation of features in the head and brain of the subject along the straight line coming out of the probe 101.
  • the ECHO-EG signal thus generated is passed to the Gating circuit and the Echo Pulsogram (EPG) block 103 of the Ultrasound Signal controller and processor 112 for further processing.
  • the ECHO-EG signal is also passed to the A/D converter 106 in the computer 107. This is required to allow processing and presentation of the signal in digital form on the computer display 110 and for storing and recalling the data.
  • the Gating circuit 104 imposes a window gate on the Echo Encephalogram signal and thereby allows observation of the Ultrasound pulses reflected from a selected location in the brain in an amplified and integrated fashion.
  • the part of the Ultrasound Signal controller and processor 112 that performs this signal processing is the Echo Pulsogram (EPG) 103 block.
  • the EPG 103 produces a signal that represents the variation of the blood flow in the brain in real-time at the selected location.
  • a typical resolution of the EPG circuit is 6 msec.
  • the Gating circuit 104 when connected to the circuits of the Ultrasound Signal controller and processor 112 and when controlled by the program in the computer 107, allows the system operator to select a location in the brain for observation and analysis.
  • the Electrocardiogram (ECG) 105 circuit records the pulsing of the heart muscle, in particular, the start of the pulsing, or the Systole.
  • the present embodiment invention uses a standard ECG card, such as marketed by AerotelTM, which includes an integral power supply in the form of a nine-volt battery.
  • the ECG circuit 105 receives its nine- volt supply voltage from the system power supply 109.
  • a protective opto-coupler one-way electrical valve
  • the three analog signals produced by the present embodiment of the invention namely, ECHO-EG, EPG, and ECG, are passed to the A D converter 106 in the computer 107 (in the present embodiment of the invention) for transformation to digital signals for processing by the computer and for storing and recreating the signal data.
  • the present embodiment of the invention includes an electrical power supply 109 with an input voltage of 220 AC Volts and DC output voltages as required by the component circuits, namely, ⁇ 5 Volts and ⁇ 12 Volts and a projected embodiment of the invention includes an output of 9 Volts DC for the ECG 105.
  • the high voltage DC power supply for the probe 101 must be a source of highly-filtered "square" DC power in the range 100-200 Volts DC.
  • FIG. 2 shows the housing or cage 200 for the primary component circuits for the present embodiment of the invention, namely the low- voltage power supply 109, the high- voltage power supply 108, the Ultrasound Signal controller and processor 112, the Gates 104, and the Electrocardiogram 105. Every slot in the cage 200 preferably has its own built-in noise-shielding circuit. On the rear panel of the cage are BNC connectors 202 for each circuit, which allow examination of the specific circuits functioning by means of an oscilloscope. This measurement allows matching up the digital signals with the analog signals.
  • the A/D Converter circuit 106 transforms the analog signals to digital signals.
  • the circuit is located on a card in one of the slots of the computer 107. It could alternatively be housed in the cage 200 of the circuits described above.
  • the ECG or Electrocardiograph circuit block 105 which is included in the present embodiment of the invention, is built around an Aerotel TM model 400 Electrocardiograph circuit board 202 which is connected to the ECG electrodes 204 placed on the subject. This is supported by a voltage regulator circuit 206 to supply its required operating voltage.
  • the ECG can be powered either by the DC power of the circuit cage 200 or by a battery.
  • a protective Optocoupler or one-way electrical valve circuit 208 can be included to protect the subject from the voltage source.
  • the ECG signal in the present embodiment of the invention provides a reference event at a selected location upstream in the bloodstream. This establishes a reference starting time for blood flowing to the brain, which can be used to determine the rate of blood flow to the brain.
  • the contraction of the heart muscle (Systola) detected by the ECG 105 which can be seen in the ECG signal in the example of the graphical data output display of the current system in Figure 4- A serves as this reference starting time.
  • the present invention includes alternative embodiments which use any other suitably precise method of determining a reference starting time for measuring the rate of blood flow to the brain.
  • the pulse in the carotid artery which supplies blood to the brain, could also be detected by either electrostatic (ECG) or acoustic means to serve as the required reference starting time.
  • the Ultrasound Signal processing circuit block 210 is discussed in detail below with respect to Figure 3 -A.
  • the Gates circuit block 104 uses methods of signal processing familiar to those versed in the art. It includes Frequency Generator circuits 212, Counter circuits 214, Timer circuits 216, and Trigger circuits 218. It chooses a segment of the actual ECHO-EG signal for integration in time to produce the EPG signal. It also includes the circuitry to display the gate on the displayed ECHO-EG signal, shown in Figure 4-A for example, so the operator can select a particular portion of the ECHO-EG display for EPG analysis.
  • Figure 3-A includes two Power Supply circuit blocks 108 and 109.
  • the low voltage power supply 109 may be any suitable conventional power supply.
  • the high voltage (100-200 Volts DC) supply 108 is preferably a source of highly-filtered "square" DC power, which is required for the reduction of noise in the system.
  • the probe 101 receives the driving ultrasound frequency (1.0 ⁇ 0.2 MHz) signal from the Transmitter circuit 113, which is controlled by a Start signal received from the computer 107 via the A/D Converter 106 ( Figure 1).
  • the probe 101 also detects the reflected Ultrasound signal which is processed by the Discriminator 302, Preamplifier 304, Bandpass Filter 306, and Gain Regulator Amplifier circuits 308 in the ECHO-EG block, referenced 102, of the Ultrasound Signal Processor 112.
  • the processed signal is modified by an Inverter 310 and a dual-diode Detector circuit 312 and processed by a Filter circuit 314 to produce the ECHO- EG signal for analysis and display.
  • the ECHO-EG signal is then amplified by an Amplifier circuit 316 and then the Gate 104 for the display (See description of Figure 4-A below) is added by an Echo Gate Switch circuit 318, Echo Gate Integrator circuit 320, and Marker Signal Switch circuit 322.
  • the unamplified ECHO-EG signal is also routed to the circuits of the EPG 103, which, based on the signal from the Gate circuit 104 process a portion of the ECHO-EG curve to produce the EPG curve.
  • the EPG includes a Pulse Gate circuit 324, the Pulse Gate Integrator circuit 326, and a pair of Lowpass Filter circuits 328 and 330 which produce the EPG signal for analysis and display. They are preferably arranged as shown in Figure 3-B.
  • the J T Converter circuit 106 which transforms the analog signals to digital signals, is located, in the present embodiment of the invention, on a card in one of the slots of the computer 107. It could also be housed in the cage 200 of the special circuits described above.
  • Figures 4-A 4-B, and 4-C are printouts of examples of graphical data output display obtained with the present embodiment of a system according to this invention as displayed on the display terminal of the computer 107.
  • the displays each include three signals: the Echo Encephalogram (ECHO-EG) signal, the Echo Pulsogram (EPG) signal, and the Electrocardiograph (ECG) signal, which are described below.
  • Figure 4-A represents data obtained from a healthy subject.
  • Figures 4-B and 4-C represent data obtained from a subject diagnosed independently to be suffering from migraine, for the right and left hemispheres of the brain, respectively.
  • the three signals graphically represented in each figure are used by the present invention to characterize the blood flow in the brain.
  • the signals, as shown in Figure 4-A are as follows:
  • the Echo Encephalogram (ECHO-EG) signal 401 graphically shows modulation in the reflected ultrasound waves detected when ultrasound waves are transmitted through the cranium to blood vessels in the brain.
  • the modulation is a function of time from the transmission of the signal and bears a one-to-one relationship with the depth of the point of reflection.
  • This means the ECHO-EG signal 401 is a representation of features in the head and brain of the subject along the straight line coming out of the probe 101 ( Figure 1).
  • the gate 418 superimposed on the ECHO-EG signal indicates the specific portion of the curve being observed in the Echo Pulsogram (EPG) signal, which corresponds to the location in the brain selected for observation.
  • EPG Echo Pulsogram
  • the Echo Pulsogram (EPG) signal 402 graphically shows modulation of the total (integrated) detected ultrasound signal from the area selected by the gate on the ECHO-EG signal 401 as a function of time. This signal 402 provides a measure in real-time of the condition of the blood vessels (contraction or dilation) represented by the selected area in the ECHO-EG signal 401.
  • the EPG signal 402 is displayed in the same units of amplitude as the ECHO-EG signal 401.
  • the Electrocardiograph (ECG) signal 403 presents graphically modulation of the signal from the heart muscle as a function of time. This signal shows the start (Systola) and other details of each heartbeat in real-time.
  • the time units of the horizontal axes are the same for the EPG signal 402 and ECG signal 403, but not for the ECHO-EG signal 401. Descriptions of additional details shown on the data output display are as follows:
  • Point Cl on the graph of the ECG signal 403 is the starting time of the Systola of the heart.
  • Point PI on the graph of the EPG signal 402 is the starting time for the pulse in the selected blood vessel in the brain.
  • the time interval 413 between points Cl and PI represents the time for blood to flow from the heart to the brain, which is also the delay between the ECG and Echo-PG signals . This interval is called tau ( ⁇ ).
  • tau In the example pictured in Figure 4-A the time ⁇ is 211 msec.
  • the depth of the measurement point is displayed in the box 414 labeled "Gate Depth" in the upper right of the graph 414. This point corresponds to the point in the ECHO-EG signal graph selected by the gate 418. In this case, the Gate Depth is 72.93 mm. This point is labeled on the graph as point El.
  • the graph of the ECHO-EG signal 401 enclosed by the gate 418 there are two peaks Al and A2 shown at the same point, referenced El, in the signal graph.
  • the peaks Al and A2 represent a blood vessel in the brain in the respective states of Diastole and Systole.
  • the graph of the EPG signal 402 which is the reflected Ultrasound signal in the area enclosed by the gate 418 as a function of time, these two points are the respective minimum and maximum points, 426 and 427, of the EPG signal 402.
  • the rise time and fall time of this signal represents the rise time and fall time of the pulse in the blood vessel in the brain.
  • the shape of the EPG waveform 402 indicates the status of the blood vessel and can be used to deduce the presence of migraine activity. This representation is the usual one for this type of graph.
  • the time for blood to flow from the heart to the brain is 211 ⁇ 6 msec.
  • the data is for a subject suffering from migraine, right side of brain.
  • the time interval 423 between points Cl and PI is 240 msec at a depth of 65.25 mm. This reading indicates a contraction of the blood vessels in this part of the brain, since the time for blood to flow to the brain is longer than average.
  • the data is for a the same subject suffering from migraine, left side of brain.
  • the time interval 433 between points Cl 431 and PI 432 is 150 msec at a depth of 65.25. This reading indicates a dilation of the blood vessels in this part of the brain, since the time for blood to flow to the brain is shorter than average.
  • the normal time for blood to flow from the heart to the brain is 211 ⁇ 6 msec.

Abstract

Procédé permettant de déterminer en temps réel des variations du diamètre effectif des vaisseaux sanguins crâniens, ce qui permet d'obtenir une indication de la migraine et consiste à déterminer le débit sanguin (402) vers le cerveau d'un sujet; à déterminer le débit sanguin intracrânien (413) dans des vaisseaux sanguins sélectionnés; à comparer le débit sanguin intracrânien (413) avec le débit sanguin déterminé (402) vers le cerveau afin de déterminer une modification du débit sanguin intracrânien par rapport au débit sanguin vers le cerveau, ce qui indique une modification correspondante du diamètre effectif du vaisseau sanguin présélectionné.
EP97918333A 1996-11-15 1997-05-13 Diagnostic non invasif en temps reel de la migraine Withdrawn EP1026989A4 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
IL11962396A IL119623A0 (en) 1996-11-15 1996-11-15 Non-invasive real time diagnosis of migraine
IL11962396 1996-11-15
PCT/IL1997/000156 WO1998024370A1 (fr) 1996-11-15 1997-05-13 Diagnostic non invasif en temps reel de la migraine

Publications (2)

Publication Number Publication Date
EP1026989A1 true EP1026989A1 (fr) 2000-08-16
EP1026989A4 EP1026989A4 (fr) 2000-08-16

Family

ID=11069486

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97918333A Withdrawn EP1026989A4 (fr) 1996-11-15 1997-05-13 Diagnostic non invasif en temps reel de la migraine

Country Status (1)

Country Link
EP (1) EP1026989A4 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4660564A (en) * 1984-04-02 1987-04-28 Teltec Electronic Equipment Ab Apparatus for measuring pulsetile part-structures within a living body
US4688577A (en) * 1986-02-10 1987-08-25 Bro William J Apparatus for and method of monitoring and controlling body-function parameters during intracranial observation
EP0498281A1 (fr) * 1991-01-31 1992-08-12 Sankyo Company Limited Mesure de la vitesse de transmission d'onde à impulsion
US5379770A (en) * 1993-12-21 1995-01-10 Nicolet Biomedical, Inc. Method and apparatus for transcranial doppler sonography

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4660564A (en) * 1984-04-02 1987-04-28 Teltec Electronic Equipment Ab Apparatus for measuring pulsetile part-structures within a living body
US4688577A (en) * 1986-02-10 1987-08-25 Bro William J Apparatus for and method of monitoring and controlling body-function parameters during intracranial observation
EP0498281A1 (fr) * 1991-01-31 1992-08-12 Sankyo Company Limited Mesure de la vitesse de transmission d'onde à impulsion
US5379770A (en) * 1993-12-21 1995-01-10 Nicolet Biomedical, Inc. Method and apparatus for transcranial doppler sonography

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
JUE WANG ET AL: "AN ULTRASONIC MEASURE SYSTEM IN CEREBRAL BLOOD FLOW DYNAMICS ANALYSIS INSTRUMENT" PROCEEDINGS OF THE ANNUAL INTERNATIONAL CONFERENCE OF THE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY,US,NEW YORK, IEEE, vol. CONF. 13, 1991, pages 199-200, XP000346240 *
See also references of WO9824370A1 *

Also Published As

Publication number Publication date
EP1026989A4 (fr) 2000-08-16

Similar Documents

Publication Publication Date Title
US5840018A (en) Non-invasive real time diagnosis of migraine
US6705992B2 (en) Ultrasound imaging enhancement to clinical patient monitoring functions
US7547283B2 (en) Methods for determining intracranial pressure non-invasively
US7572223B2 (en) Integrated physiology and imaging workstation
US6328694B1 (en) Ultrasound apparatus and method for tissue resonance analysis
CA2123536C (fr) Detecteur ultrasonique de la vitesse d'ecoulement du sang
US20060100530A1 (en) Systems and methods for non-invasive detection and monitoring of cardiac and blood parameters
EP2392262A1 (fr) Procédés et systèmes pour localiser et illuminer acoustiquement une zone cible souhaitée
Baskett et al. Screening for carotid junction disease by spectral analysis of Doppler signals
JP6783863B2 (ja) 血行管理のためのマルチサイト連続超音波流量測定
CN216702565U (zh) 一种可穿戴可视化的超声无创监控仪器
US20080039722A1 (en) System and method for physiological signal exchange between an ep/hemo system and an ultrasound system
EP1026989A1 (fr) Diagnostic non invasif en temps reel de la migraine
Prepared by the Safety Group of the British Medical Ultrasound Society Guidelines for the safe use of diagnostic ultrasound equipment
RU2353290C2 (ru) Устройство диагностики состояния плода в дородовый период
CN113440165A (zh) 一种可穿戴可视化的超声无创监控设备
Joseph et al. Image-free technique for flow mediated dilation using ARTSENS® Pen
Lee et al. A clinical evaluation of a noninvasive electromagnetic flowmeter
KR20030008722A (ko) 태아 심박 원격 진단 시스템 및 그 방법
Raymond et al. Optimal resources for ultrasonic examination of the heart
RU2098011C1 (ru) Способ диагностики нарушения кровенаполнения поджелудочной железы
US20050277840A1 (en) Method and system for processing periodic physiological signals
Gramiak et al. Report of the inter‐society commission for heart disease resources Optimal resources for ultrasonic examination of the heart
Kumar et al. ECG abnormalities detection using doppler shift method
CN100371940C (zh) 周期性生理信号处理系统

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19990608

A4 Supplementary search report drawn up and despatched

Effective date: 20000406

AK Designated contracting states

Kind code of ref document: A4

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

17Q First examination report despatched

Effective date: 20010110

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20010721