[go: up one dir, main page]

WO2007032682A1 - Sonde allongée d’imagerie en temps réel par ultrasons à insérer dans le corps - Google Patents

Sonde allongée d’imagerie en temps réel par ultrasons à insérer dans le corps Download PDF

Info

Publication number
WO2007032682A1
WO2007032682A1 PCT/NO2005/000340 NO2005000340W WO2007032682A1 WO 2007032682 A1 WO2007032682 A1 WO 2007032682A1 NO 2005000340 W NO2005000340 W NO 2005000340W WO 2007032682 A1 WO2007032682 A1 WO 2007032682A1
Authority
WO
WIPO (PCT)
Prior art keywords
array
ultrasound
probe
ultrasound imaging
imaging
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.)
Ceased
Application number
PCT/NO2005/000340
Other languages
English (en)
Inventor
Bjørn A. J. ANGELSEN
Tonni F. Johansen
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.)
Individual
Original Assignee
Individual
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
Application filed by Individual filed Critical Individual
Priority to PCT/NO2005/000340 priority Critical patent/WO2007032682A1/fr
Publication of WO2007032682A1 publication Critical patent/WO2007032682A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/48—Diagnostic techniques
    • A61B8/483—Diagnostic techniques involving the acquisition of a 3D volume of data
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/12—Diagnosis using ultrasonic, sonic or infrasonic waves in body cavities or body tracts, e.g. by using catheters

Definitions

  • Extended, ultrasound real time imaging probe for insertion into the body.
  • the invention relates to methods, ultrasound probes, and instrumentation for real time 3D imaging around the tip of an ultrasound probe that can be inserted into the body, either through natural openings or through surgical wounds.
  • Real time (Rt) two-dimensional (2D) and three-dimensional (3D) ultrasound imaging around the tip of a flexible ultrasound probe is in many situations a sought after tool, both for diagnosis and for guidance of procedures. Examples of such procedures are placement of devices in the heart ventricles and atria, guidance of electrophysiology ablation, or guidance in minimal invasive surgery. In these cases, the ultrasound probe gets in direct contact with the blood path, and it is then a great advantage to use factory-sterilized, disposable probes. This requires that the manufacturing cost of the probes can be kept low.
  • Such imaging around a probe tip is done by lateral scanning of a pulsed ultrasound beam from the probe tip, where 3D imaging requires scanning in two lateral directions within a volume, while 2D imaging is obtained by lateral scanning in one direction across a surface.
  • the volume scanning is ideally done with a two-dimensional matrix array where the element width is less than ⁇ /2 in both directions, where ⁇ is the wave-length of the ultrasound in the tissue.
  • ⁇ is the wave-length of the ultrasound in the tissue.
  • the small size of the elements of the matrix probe also makes it difficult to manufacture the matrix arrays for ultrasound frequencies above ⁇ 5 MHz.
  • the probe is further a need for the probe to be flexible, for example for insertion into the vessels and the heart as a catheter. In this situation one could also want to control flexing of the tip from the external instrument. In other situations, like endoscopic surgery, one would like to have a stiff probe.
  • the present invention provides a solution to these problems by using mechanical direction steering of the ultrasound beam in one direction, and for 3D imaging the ultrasound beam is electronically scanned in the 2 nd direction.
  • 2D imaging one can mechanically direction scan a single element transducer with a fixed focus, or an annular array transducer to obtain electronically steered dynamic focusing.
  • annular array one can conveniently use solutions as described in US Patent No 6,540,677 to increase the sensitivity and reduce the number of wires connecting between the probe tip and the external imaging instrument.
  • the electronic bean scanning in the 2 nd direction can be obtained by a linear phased, curvilinear switched, or linear switched array.
  • Example embodiments of the mechanical direction scanning of the beam are shown by rotation of the array by a flexible cable through the probe, or mechanical wobbling of the array, for example by hydraulic means.
  • depth variable focusing i.e. dynamic focusing
  • both of the transmit and the receive beam of the ultrasound beam in the mechanical scan direction by linear combination of the received RF signal from neighboring mechanical scan directions.
  • 2D imaging one can also obtain electronic steering of the focus symmetrically around the beam axis with an annular array as described above.
  • 3D imaging one obtains electronic steering of the focus in the electronic scan direction (referred to as the azimuth direction) with the electronic array beam former.
  • the mechanical scan direction referred to as the elevation direction
  • one can then for slow moving objects obtain depth variable focusing by linear combination of the received RF-signal from neighboring beams in the elevation direction.
  • 3D electronic steering of the beam focus in the elevation direction can also be obtained by dividing the array elements in the elevation direction, with for example a switched aperture focusing, or a steerable or switchable signal delay based focusing.
  • the elevation focusing can be done by electronics at the tip of the probe, to reduce the number of wires connecting the tip of the imaging probe and the external imaging instrument.
  • Sub-aperture beam forming in the azimuth direction by electronics at the tip of the probe also provides a reduction in the number of wires connecting the imaging probe tip and the external imaging instrument.
  • the probes can be made both flexible and stiff, for best adaption to the application.
  • the tip of the flexible probe can be direction steered (flexed) through wires along the periphery of the probe that are stretched/released through handles at the outside instrument.
  • FIG. 1 shows an overview of a real time 2D or 3D imaging system with a probe according to the invention
  • FIG. 2 shows an example embodiment of the distal tip of a flexible, probe according to the invention where the mechanical beam scanning is obtained by a mechanical rotation of the array
  • FIG. 3 shows examples of three types of arrays for electronic azimuth scanning of the beam with their corresponding image formats for 3D imaging
  • FIG. 4 shows an example of a 3D region that can be scanned by an ultrasound beam from the distal probe tip of the type shown in FIG. 2, and
  • FIG. 5 shows yet another arrangement of 3D imaging with a rotating array according to the invention
  • FIG. 6 shows an example 2D display of the conic image on a screen
  • FIG. 7 shows yet another arrangement with two rotating transducers according to the invention.
  • FIG. 8 shows a method of combining the element signals from a sub-aperture group of neighboring elements, to reduce the number of signals that must be connected to the imaging instrument
  • FIG. 9 shows example transmitted beam profiles with grating lobes that is found with transmitting with less than all array elements in a sub-aperture arrangement
  • FIG. 10 shows yet another method of mechanical scanning of the ultrasound beam from the distal tip of the probe, according to the invention.
  • FIG. 11 shows an example of a 3D region that can be scanned with an ultrasound beam generated by the arrangement in FIG. 10, and
  • FIG. 12 shows an example of an optical angular position resolver for measuring the mechanical rotation of the array in a probe tip like displayed in FIG. 2, and
  • FIG. 13 shows an example of an optical angular position resolver for measuring the angular wobbling of the array for a probe tip of the type shown in FIG. 10.
  • the invention relates to an ultrasound real time imaging system, which in a typical embodiment is composed of the components shown in FIG. 1, where 100 shows an elongated imaging probe with a distal imaging tip 101 and a proximal end 102 that is connected to an utility console interface 103.
  • the imaging ultrasound beam is transmitted from the distal tip of the probe and is for 3D imaging enabled to be scanned within a volume region 110 to be imaged, and for 2D imaging can be enabled to be scanned within a sector surface 111.
  • the utility interface further connects via the cable 104 the probe signals to an ultrasound imaging instrument 105.
  • the imaging instrument has an image display screen 106 for visualization of the images and also other information, and a key board interface 107 for user control of the instrument.
  • the imaging probe 100 is a particularly flexible catheter probe for example allowing double curving of the probe, which has advantages for imaging inside tortuous vessels and the heart cavities.
  • the probe can be much less flexible, close to stiff, for example in minimally invasive surgery where the probes would be inserted through a trocar.
  • the flexible probe one often would stretch wires along the periphery of the probe, where the wires can systematically be manipulated by control organs 108 at the utility interface 103 for flexing the tip of the probe in one or two directions.
  • the invention specially relates to methods of scanning the ultrasound beam within the volume 110 of 3D space and surface 111 for 2D imaging, from the distal tip of such an elongated probe.
  • FIG. 2 shows a first example embodiment according to the invention of the distal tip 101 of such an elongated probe 100.
  • FIG. 2a shows a solution for 3D imaging where 201 shows an array transducer that allows electronic direction steering of the ultrasound beam, while FIG. 2b shows simplifications for 2D imaging along a conical surface where the array is modified to a single element or annular array transducer 216.
  • the mechanical scan mechanism and catheter design in other respects are the same for the 2D and 3D imaging.
  • the array 201 typically can be a linear phased array transducer with a set of array elements 202, or the array can also for example be a switched array or a curved switched array.
  • the array elements 202 are electrically connected to an electronic circuit 203, with an acoustically isolating material (backing material) 213 between the array and the circuit, to avoid ringing acoustic pulses from the back side of the array.
  • the circuit 203 typically contains receiver amplifiers with switching circuits between transmit and receive of the ultrasound pulses.
  • it can also contain steerable or selectable delay circuits of the receive element signals to combine the signals from neighboring elements in sub-aperture groups into a reduced number of sub-aperture signals, so that the connection of the signals between the array and the utility console can be obtained by less number of wires than the total number of elements in the array aperture, as described in relation to FIG. 8a.
  • the number of wires between the imaging tip and the external imaging instrument can also be reduced with synthetic aperture techniques, as further described below in relation to FIG. 8c. This is important to reduce the diameter of the catheter.
  • the array 201 and the circuit 203 are mounted in an array holder unit 204 that is connected to a flexible rotation cable 205 typically made of double helix spun wires, like a speedometer wire used in cars.
  • the rotation cable 205 has a core of electric cable wires 206 that connects the array and circuit to the external utility console 103, as shown in FIG. 1.
  • the wire is on the distal end connected to a motor 207 in the utility console, and transmits the motor rotation to rotation of the transducer array 201 around the cable axis 208.
  • the rotating cable would typically be covered with a plastic sheath 209, but this sheath could in some embodiments be left out.
  • the electronic circuit 203 can also be left out, and the cable wires 206 would then connect directly to the array elements 202.
  • a position sensor 210 would typically be mounted at the probe tip to measure the rotation ⁇ , indicated as 211, of the array holder 204 and array 201 in relation to the catheter sheath 209.
  • This position sensor could typically be of optical types like described in FIGS. 12 and 13, but other methods like electromagnetic angular position sensors could also be used.
  • Accurate monitoring of the angular direction of the array is used in the image reconstruction to minimize the effect of variable angular rotation differences along the cable 205 from the proximal to the distal end, as these differences might vary with rotation angle and bending of the probe.
  • Other position sensors that relate the rotation to a more global reference, like the patient surface, for example using electromagnetic induction, can also be used.
  • Such sensors are well known to any-one skilled in the art, and would typically be used to merge ultrasound images from different locations of the probe tip, or relate the ultrasound images to images obtained with other modalities like XRay or MR images, or priorly taken ultrasound images, or a treatment tool like a surgical tool, or an ablation tool, etc.
  • the invention also covers embodiments where the rotation of the array holder 204 is mounted directly to a rotating motor at the tip of the array, for example an electric motor or a hydraulic motor.
  • a linear array embodiment of the array 201 one can obtain electronic direction steering of the ultrasound beam in a sector format with phased array operation as illustrated in FIG. 3a.
  • the full opening angle of the sector scan is ⁇ , indicated by 303.
  • Beam steering in a weakly opened sector with a switched linear curved array as illustrated in FIG. 3b can also be used.
  • wide band transducers for example as shown in US Pat 6,645,150, or US Pat 6,761,692
  • Beam steering in a rectangular format with a switched linear array as illustrated in FIG. 3c is then interesting for high frequencies.
  • FIG. 4 illustrates a typical beam 401 obtained with simultaneous electronic steering of the beam with a phased array in the 2D sector format in FIG. 3a, and mechanical rotation of the array.
  • the phased array beam steering provides a beam angle ⁇ (402) relative to the rotation axis of the array.
  • the mechanical rotation of the array gives a beam angle ⁇ (403) relative to a reference.
  • the combined electronic and mechanical direction steering of the beam allows collection of ultrasound backscatter data from a sub-spherical volume region with boundaries 400 determined by the 2D sector 405 and the spherical range of the 2D image 406.
  • an opening angle ⁇ (407) of the 2D sector one could ideally mount the array with a skewed angle to the probe axis 208, so that the normal of the array forms an angle ⁇ /2 to the probe axis, shown as 212 in FIG. 2.
  • the 3D beam along the probe axis is then obtained with steering of the beam to the outer right side 408 of the 2D sector, and this beam direction can be obtained with all mechanical angular directions ⁇ of the array, due to the degeneration of the spherical to rectangular coordinate transform for this polar direction.
  • the ultrasound beam has a certain width determined by the beam focusing and the diffraction, one then can shoot less 2D beams in the directions for small values of ⁇ , than for large values of ⁇ .
  • all 2D sectors contain ultrasound beams with large angles ⁇ , while smaller values of ⁇ are only found in selected 2D sectors, so that the beam density is kept approximately constant in the real 3D space.
  • D ⁇ of the beam in the ⁇ direction at the maximal range R indicated as 409 in FIG. 4
  • the number of beams required as a function of ⁇ for adequate 3D sampling of the image at this angle is
  • N 3D ( ⁇ ) 2 ⁇ ( 1 -cos ⁇ )R 2 /A b (3)
  • An adequate diameter of such a catheter probe for intra-cardiac echo applications is 3 mm.
  • the element pitch becomes ⁇ 50 ⁇ m, which allows ultrasound wave lengths down to lOO ⁇ m corresponding to frequencies up to 15MHz.
  • FIG. 5 shows a modification compared to FIG. 2 of the rotating array
  • the array 501 with elements 502 and an optional electronic circuit 503 is mounted on the side of the flexible, rotating wire shaft 205.
  • Rotating the shaft around its axis 208 for example in the clockwise direction 504 produces a "donut" like 3D volume scanning region of the ultrasound beam 505 limited by the sector opening lines 506 and the depth range 507.
  • Other arrays like switched linear or curvilinear arrays can also be used.
  • the array can according to the invention be mounted with a variety of angles relative to the rotation axis 208, to provide a variety of 3D scanning regions for a variety of applications.
  • the electronic direction steering array 201 could typically be exchanged with a single element, fixed focus transducer, or an annular array transducer as 215 in FIG. 2b with annular elements 216.
  • the 2D transducer elements is mounted on a backing material 217 and annular array elements can also be connected to an integrated circuit 218 with receiver amplifiers and also beam forming circuits for electronic focus steering, where for example methods and implementations according to US Patent No 6,540,677 could be used.
  • the mechanical scanning system is otherwise the same as for the 3D imaging probe, which gives a lateral scanning of the ultrasound beam across a conical surface illustrated as 601 in FIG. 6a, where the opening angle of the conical surface is given by the direction ⁇ of the transducer surface indicated as 219 in FIG. 2b.
  • FIG. 6b An example of visualization of the 2D conic image data on a flat screen, is shown in FIG. 6b.
  • the physical, conical surface 601 across which the beam is scanned is divided for example along 4 radial lines 602 to be separated into 4 surface regions 603, 604, 605, and 606. These surface regions are then projected onto the plane sectors 607, 608, 609, and 610 displayed on the image screen in the same sequence.
  • the images are typically shown as grey scale images for the amplitude of the reflections that gives a tissue image, or in a color scale for movement velocities of the object, according to well-known principles.
  • FIG. 7 shows a similar probe tip as in FIG. 2, but with an added transducer array 701 with a beam 702 at the circumference of the rotating array holder unit 204.
  • This transducer can again be a single element transducer or an annular transducer array, similar to the forward looking array 201.
  • the 2D image would then be displayed as 703 on the screen, typically together with the forward looking image cone as in FIG. 6.
  • FIG. 8a Example embodiments of such sub-aperture beam forming is shown in FIG. 8a, where a group 801 of the array elements 202 forms one of the sub-apertures.
  • the number of elements in the sub-aperture group is 4, but other numbers of 2, 3, etc. can be used.
  • the signals from each element are fed to transmit/receive switches 802 that in receive mode feed the signal to receiver amplifiers 803.
  • the outputs of the receiver amplifiers are in this example embodiment of sub-aperture processing fed to a cross-point switch 804 that connects the element signals to a summing delay line system 805 with a set of delay elements 806, so that any of the signals can be connected to any delay-point 807.
  • the output 808 of the delay line system is then fed via the cable 206 to the external imaging instrument where the sub-aperture signals are combined to a complete beam, or several parallel beams, according to known methods.
  • FIG. 8b An example embodiment of a delay cell is shown in FIG. 8b, where 809 indicates a differential amplifier, and the signal delay is given by the resistor 810 and capacitor 811.
  • the transfer function of this delay cell is
  • the transmit beam of the sub-aperture can in its most general form be generated by a sub- aperture transmit beam former 813 that feeds a set of element driver amplifiers 814 with transmit pulses that have intermediate delays given by the sub-aperture transmit beam former 813 and set up by the sub-aperture control bus 812.
  • the transmit trigger pulse for each sub-aperture transmit beam-former is conveniently transferred on the receive line 808 for each sub-aperture, to limit the number of wires connecting the catheter tip and the imaging instrument.
  • the sub-aperture transmit beam-former can in some applications be left out, where only a sub-set of the elements in the sub-aperture, for example 1 or 2 elements, are used to transmit at each sub-aperture. In these cases, the transmit beam would get grating lobes as illustrated in FIG. 9 for a wide band transmit pulse.
  • This Figure shows the amplitude of the far-field beam profile of the transmitted beam as a function of azimuth angular direction from the beam center axis.
  • each sub-aperture has 3 elements, and a single element is used to transmit from each sub-aperture.
  • 901 shows the main lobe and 902 shows the grating lobes of the beam where the transmit elements have the same position within each sub-aperture (periodic position of the transmit elements).
  • 903 shows the main lobe of the beam where the transmit elements have a close to random variation of their position within each sub-aperture, and 904 shows the side lobes for this random location.
  • the sharp peak grating lobe disappears, and we get a more even leveled side lobes which are higher than the side lobes for the transmit elements with a fixed position in each sub- aperture.
  • the sidelobes close to the main lobe of the sub-set transmit apertures are close to the sidelobes for the fully sampled aperture, while the sidelobe/grating lobe level 904 at large distance from the main lobe is ⁇ 20 dB higher than for the fully sampled aperture 910.
  • the transmit beam grating lobes are also reduced by focusing of the beam. Their effect on the image is further reduced since the receive beam which uses the full sub-apertures is missing these grating lobes, hence attenuating the back scattered signal from these lobes.
  • the transmitted grating lobes would generate some noise in the image, and lowest noise images would be obtained with a full sub-aperture transmit beam former, illustrated as 813 in FIG. 8a.
  • the total array aperture is in this Figure divided in the middle into two, equal groups, Aperture 1 and Aperture 2.
  • the array elements 202 are pair wise from each group connected to 2 to 1 multiplexers 820, which through the control signal 821 connect either the elements from Aperture 1 (as shown in the Figure) or Aperture 2 to the wires 822 that connects through the probe to the external imaging instrument.
  • image beams are in an alternating sequence collected from Aperture 1 and Aperture 2, and then the RF signal for the two beams from Aperture 1 and Aperture 2 are combined with the Synthetic aperture technique known to anyone skilled in the art, into a single beam focused at all depths with focus width determined by the full aperture.
  • Dynamic focusing of the beam in the elevation direction can be achieved by dividing the array elements in the elevation direction, and feeding the element signals to a sub- aperture beam former like exemplified in FIG. 8a for each azimuth position of the elements.
  • the outputs of the elevation focusing beam formers from neighboring azimuth elements could then in turn be fed to azimuth sub-aperture beam formers as described.
  • For the elevation focusing one would only need small delays, as there is no large electronic direction steering of the beam in the elevation direction. Small electronic direction steering is highly interesting to use parallel receive beams in the elevation direction also, to increase the frame rate, in a manner known to anyone skilled in the art.
  • the transmit beam former 813 of FIG. 8a For the elevation focusing of the transmit beam, one would in most situations avoid the transmit beam former 813 of FIG. 8a and transmit with a central group of elevation elements with a fixed pre-focusing. This gives an adequately elevation focused transmit beam, as the receive focusing provides the dynamic elevation focusing. With parallel elevation beams, the elevation width of the transmit beam must also be sufficiently high.
  • FIG. 10 Yet another embodiment for the mechanical beam scanning both for 2D and 3D imaging according to the invention, is shown in FIG. 10, where 1001 shows the combined array and integrated circuit assembly that is enclosed in a sub-spherical dome 1003.
  • the array would provide electronic direction steering of the ultrasound beam in one duirection, as for example shown in FIG. 3, while for 2D imaging the array could typically be a single element transducer with fixed focus or an annular array as described in relation to FIG. 2b.
  • the assembly 1001 is connected to a flexible member 1004 that locates the assembly in the middle of the dome and also feeds electric signal wires from the array and electronic circuit to the imaging instrument.
  • the member 1004 can for example be made as a printed flex circuit or similar structure.
  • the signal wires can connect to a more convenient type of cable 1006 at the interface 1005 to be fed throughout the probe to connect to the utility console 103 of FIG. 1.
  • the probe in this example embodiment contains two hydraulic channels 1009 and 1010 that can inject or remove fluid from the chambers 1007 and 1008, that are separated by the flexing member 1004.
  • the interior compartments 1002, 1007, and 1008 are filled with a fluid, preferable water with physiological composition. Injecting fluid through the tube 1009 into compartment 1007 while removing fluid through tube 1010 from compartment 1008 causes the array/circuit assembly 1001 to rotate in the clockwise direction indicated by the arrow 1012. The opposite rotation is obtained by injecting fluid through tube 1010 into chamber 1008 while removing fluid through tube 1009 from chamber 1007.
  • valves at the distal end of the channel one can also construct designs, where one fluid channel feeds continuously fluid out to the array, and the fluid is either dumped out of the probe at the tip, or returned to the proximal end of the probe through a separate channel.
  • a continuous forward filling with fluid is obtained by the channels 1014 that feeds fluid from the compartments 1007 and 1008 into the compartment 1002, while the channel 1015 feeds fluid from the compartment 1002 to the outside front of the probe dome.
  • This continuous flow of fluid to the front of the dome improves acoustic contact between the dome and the object contact surface, or can spill into the blood when the probe is inserted into a blood-filled region.
  • the draining of the fluid from compartment 1002 can be done through the probe to its proximal, outside end, by a specific channel through the probe from the distal to the proximal end.
  • the probe is on its proximal end connected electrically and hydraulically to the utility console 103 of FIG. 1, which for this embodiment also contains a hydraulic pumping and control system that injects or removes fluid through the channels 1009 and 1010 and provides the wobbling motion of the array assembly 1001.
  • the array can typically be a linear phased array with a 2D azimuth scan normal to the wobbling direction which is in the elevation direction of the 2D scan. This provides a three-dimensional scanning of the ultrasound beam as illustrated in FIG. 11, where 1101 indicates an ultrasound transmit/receive beam for the array/circuit assembly 1001 with azimuth angle ⁇ illustrated as 1102 within a 2D sector 1103.
  • the wobbling of the array/circuit assembly 1001 provides a steerable elevation angle ⁇ of the 2D sector and the beam indicated as 1104. It should be clear that this hydraulic wobbling mechanism also allows for mounting of the array so that the wobbling axis forms an angle other than 90 deg to the probe tip axis, to adjust the detailed location of the 3D imaging region in relation to the probe tip axis to the particular application at hand.
  • N 30 ⁇ ⁇ R 2 /A b (5)
  • N 3D 2056.
  • 70 ⁇ sec per beam it takes 144 msec to capture the image, giving ⁇ 6 3D frames per second.
  • Using 2, 3, and 4 parallel beams increases the 3D frame rate to 12, 18, and 24 3D frames per second with this opening angle.
  • This scan method could hence conveniently be used with down to one single parallel receive beam, where the high 3D frame rates are obtained by decreasing the 3D scan opening angle below ( ⁇ /
  • the mechanical wobbling of the array assembly 1001 would provide a lateral sector scanning of the ultrasound beam that would provide a 2D sector image of tissue structures and scatterer velocities and displacements that is displayed according to known methods. It should also be clear from FIG. 10 that the middle position of the array assembly 1001 could also be rotated to provide sector scans with an angle to the probe tip. The assembly could also be rotated to also provide sector scans that have a cross sectional position to the probe axis.
  • FIG. 12 illustrate an optical position sensor for the rotating scan system of FIGS. 2, 5 and 7, and FIG. 13 illustrate an optical position sensor for the wobbling scan system in FIG. 10.
  • FIG. 12a shows the rotating array holder 204 with the rotating drive cable 205, that rotates the array in the direction indicated by 1204.
  • the rotating drive cable contains in this example embodiment also an optical fiber 1201 that feeds light into a transparent sub-part 1202 of the array holder.
  • the surface of the sub-part 1202 is partly covered with a light inhibiting film at the end face and also at grating lines 1203 in a periodic pattern along the circumference of 1202 that inhibits light to shine out through the circumference, while between the grating lines the light is allowed to shine through.
  • the distance between the grating lines is equal to the width of the grating lines within the accuracy of the manufacturing.
  • Two optical fibers 1205 and 1206 picks up light that shines through the circumference of 1202 and feeds the light back to the instrument where it is converted to electrical analog signals by for example photo transistors and subsequently converted to digital form for processing to accurately detect the rotational angle of the array holder 204.
  • Example signals after the phototransistors for the two fibers are shown in FIG. 12b where 1210 shows a typical signal x(t) from fiber 1205 and 1211 shows a typical signal y(t) from fiber 1206. Due to spread of the light, the signals are close to sinusoidal in shape.
  • the two fibers 1205 and 1206 have a distance between each other close to 1/4 of the period of the grating lines, which gives close to 90 deg phase lag of y(t) in relation to x(t).
  • FIG. 13a A similar optical position sensor for the wobbling system in FIG. 10, is shown in FIG. 13a, where 1001 shows the array holder within the dome 1003.
  • a variable reflectance grating 1301 composed of stripes 1302 with high reflectance periodically arranged with stripes 1103 of low reflectance.
  • the distance between the pickup areas of fiber 1306 and 1307 is 1/4 of the grating period, so that the signals in the two fibers 1306 and 1307 produces signals x(t) and y(t) as in FIG. 12b, which is further processed to resolve the angular position of the array holder similar to Eqs.(6,7).
  • FIG. 12a is shown a position sensor with a transmitting grating, while it is clear to any one skilled in the art that a reflecting grating could equally well be used similar to the sensor in FIG. 13a, for which sensor one could also use a transmitting grating.
  • the same fiber can also be used for transmitted and reflected light using for example a transmitting mirror as shown in FIG. 13b.
  • the light source 1310 shines a light beam 1311 through a transmitting mirror 1312 so that the light enters the fiber 1313.
  • the light reflected at the distal end of the fiber will then come out of the tip and be reflected at the mirror 1312 so that the reflected light is separated into the beam 1314 that hits the detector 1315 and is converted to an electrical signal and digitized.
  • Other methods of angular position sensing can be based on electromagnetic methods of measuring the array angle in relation to the tip, and also in relation to the external world.
  • the frequency and bandwdith of the arrays can be selected freely within the scope of the invention.
  • wide band or multi-band transducers as described in US Patent 6,645,150 or based on ceramic films as described in US Patent 6,791,692
  • the overview image could for example be used to guide one's way in the cardiac chambers to move the probe tip close to an electrophysiology ablation scar, and then evaluate the scar with the high resolution short range image.
  • the probes can also be used with the new dual frequency pulse technique described in PCT Application PCT/NO20005/00278. Example array designs for such applications are given in US Provisional Patent Application of July 26 by B. A. J. Angelsen et. al. With such dual frequency techniques the probes could be used for improved imaging of ultrasound contrast agent micro-bubbles, micro-bubbles produced by extracorporal blood oxygenators or in decompression situations, micro-calcifications found in tumors and atherosclerotic plaque, and assessment of tissue properties.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Biophysics (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Pathology (AREA)
  • Radiology & Medical Imaging (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Ultra Sonic Daignosis Equipment (AREA)

Abstract

La présente invention concerne une sonde d’imagerie par ultrasons permettant l’imagerie par ultrasons tridimensionnelle en temps réel depuis le bout de la sonde qui peut être insérée dans le corps. Le faisceau d’ultrasons est électroniquement numérisé dans un plan azimut bidimensionnel à barrette linéaire et la numérisation dans le sens d’élévation à angle droit vers le plan azimut est obtenue par mouvement mécanique de la barrette. Ce mouvement est obtenu soit par rotation de la barrette par le biais d'un fil flexible, soit par sa rotation à l’aide d’une activation hydraulique, par exemple. La sonde peut être flexible ou rigide et il faut noter que le mode de réalisation flexible est particulièrement intéressant pour l’imagerie de cathéter dans le cœur et dans les vaisseaux et le mode de réalisation rigide a des applications dans le cadre d'une chirurgie minimalement invasive et autres procédures. La conception de la sonde permet une fabrication à coût réduit qui permet aux sondes stérilisées à l’usine d’être jetées après utilisation.
PCT/NO2005/000340 2005-09-15 2005-09-15 Sonde allongée d’imagerie en temps réel par ultrasons à insérer dans le corps Ceased WO2007032682A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/NO2005/000340 WO2007032682A1 (fr) 2005-09-15 2005-09-15 Sonde allongée d’imagerie en temps réel par ultrasons à insérer dans le corps

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/NO2005/000340 WO2007032682A1 (fr) 2005-09-15 2005-09-15 Sonde allongée d’imagerie en temps réel par ultrasons à insérer dans le corps

Publications (1)

Publication Number Publication Date
WO2007032682A1 true WO2007032682A1 (fr) 2007-03-22

Family

ID=36118595

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NO2005/000340 Ceased WO2007032682A1 (fr) 2005-09-15 2005-09-15 Sonde allongée d’imagerie en temps réel par ultrasons à insérer dans le corps

Country Status (1)

Country Link
WO (1) WO2007032682A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012161770A1 (fr) * 2011-03-22 2012-11-29 Boston Scientific Scimed, Inc. Dispositif d'imagerie ultrasonore en champ lointain et en champ proche
US9078593B2 (en) 2008-02-05 2015-07-14 Fujitsu Limited Ultrasound probe device and method of operation
CN113712631A (zh) * 2021-09-02 2021-11-30 南京广慈医疗科技有限公司 一种随机分布三维相控阵探头的制备方法
US11826200B2 (en) * 2017-10-04 2023-11-28 Verathon Inc. Multi-plane and multi-mode visualization of an area of interest during aiming of an ultrasound probe

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5271402A (en) * 1992-06-02 1993-12-21 Hewlett-Packard Company Turbine drive mechanism for steering ultrasound signals
US5699805A (en) * 1996-06-20 1997-12-23 Mayo Foundation For Medical Education And Research Longitudinal multiplane ultrasound transducer underfluid catheter system
US6540677B1 (en) * 2000-11-17 2003-04-01 Bjorn A. J. Angelsen Ultrasound transceiver system for remote operation through a minimal number of connecting wires
US20050119572A1 (en) * 2003-10-10 2005-06-02 Angelsen Bjorn A. Probe for 3-dimensional scanning and focusing of an ultrasound beam

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5271402A (en) * 1992-06-02 1993-12-21 Hewlett-Packard Company Turbine drive mechanism for steering ultrasound signals
US5699805A (en) * 1996-06-20 1997-12-23 Mayo Foundation For Medical Education And Research Longitudinal multiplane ultrasound transducer underfluid catheter system
US6540677B1 (en) * 2000-11-17 2003-04-01 Bjorn A. J. Angelsen Ultrasound transceiver system for remote operation through a minimal number of connecting wires
US20050119572A1 (en) * 2003-10-10 2005-06-02 Angelsen Bjorn A. Probe for 3-dimensional scanning and focusing of an ultrasound beam

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9078593B2 (en) 2008-02-05 2015-07-14 Fujitsu Limited Ultrasound probe device and method of operation
WO2012161770A1 (fr) * 2011-03-22 2012-11-29 Boston Scientific Scimed, Inc. Dispositif d'imagerie ultrasonore en champ lointain et en champ proche
US8801617B2 (en) 2011-03-22 2014-08-12 Boston Scientific Scimed Inc. Far-field and near-field ultrasound imaging device
US11826200B2 (en) * 2017-10-04 2023-11-28 Verathon Inc. Multi-plane and multi-mode visualization of an area of interest during aiming of an ultrasound probe
CN113712631A (zh) * 2021-09-02 2021-11-30 南京广慈医疗科技有限公司 一种随机分布三维相控阵探头的制备方法
CN113712631B (zh) * 2021-09-02 2024-05-03 南京广慈医疗科技有限公司 一种随机分布三维相控阵探头的制备方法

Similar Documents

Publication Publication Date Title
US7699782B2 (en) Extended, ultrasound real time 3D image probe for insertion into the body
US20050203416A1 (en) Extended, ultrasound real time 2D imaging probe for insertion into the body
US11559277B2 (en) Ultrasound 3D imaging system
US9486143B2 (en) Intravascular forward imaging device
US6045508A (en) Ultrasonic probe, system and method for two-dimensional imaging or three-dimensional reconstruction
US11000185B2 (en) Devices, systems, and methods for visualizing an occluded vessel
CA1304493C (fr) Systeme d'imagerie ultrasonique utilise en endoscopie
US5876345A (en) Ultrasonic catheter, system and method for two dimensional imaging or three-dimensional reconstruction
Angelsen et al. Which transducer array is best?
JP4582827B2 (ja) 超音波診断装置
US20060173350A1 (en) Systems and methods for three dimensional imaging with an orientation adjustable array
US20090247879A1 (en) Extended ultrasound imaging probe for insertion into the body
US20120179044A1 (en) Ultrasound 3d imaging system
KR20110137829A (ko) 범용 복수 개구 의료용 초음파 프로브
WO2014099797A2 (fr) Ensemble cathéter à extrémité raccourcie
US7691060B2 (en) Probe for 3-dimensional scanning and focusing of an ultrasound beam
WO2007032682A1 (fr) Sonde allongée d’imagerie en temps réel par ultrasons à insérer dans le corps
US20250169792A1 (en) Ultrasound 3d imaging system
O'donnell et al. Synthetic phased array imaging of coronary arteries with an intraluminal array
JP2004350703A (ja) 超音波診断プローブ装置
JP2914871B2 (ja) 超音波診断装置
Halliwell Ultrasonic imaging in medical diagnosis
Von Behren et al. External Diagnostic Ultrasound Capabilities, Limitations, And Future Trends
Zhi et al. A simple 2-D ultrasound array and front-end electronics for 3-D volumetric imaging
Wilhjelm et al. In vitro imaging of the carotid artery with spatial compound imaging

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 05797332

Country of ref document: EP

Kind code of ref document: A1