Apparatus and method for tracking medical ultrasound objects

Abstract

The vascular occlusion treatment system includes: an ultrasound imaging system having an imaging control circuit communicatively coupled to an ultrasound imaging probe and a display screen; and an ultrasound vibration system having an ultrasound generator operably coupled to a medical ultrasound object, such as an ultrasound catheter. The ultrasound catheter has a core wire with a distal tip. The ultrasound generator has a generator control circuit that alternately switches between an ultrasound operating frequency and a tracking frequency. The generator control circuit sends a notification to the imaging control circuit when the generator control circuit has switched from the ultrasound operating frequency to the tracking frequency. The imaging control circuit responds by initiating a search in the ultrasound imaging space to locate the distal tip that is vibrating at the tracking frequency and indicating the position of the distal tip in the ultrasound image displayed on the display screen.

Description

Technical Field

[0001] The present invention relates to tracking medical objects within a patient, and more particularly, to apparatus and methods for tracking medical ultrasound objects within a patient, such as in a vascular occlusion treatment system. Background Art

[0002] An ultrasonic catheter system is disclosed in U.S. Pat. No. 8,690,819, in which an ultrasound-activated catheter (hereinafter referred to as an ultrasonic catheter) is used to perform plaque removal and interrupt vascular blockages, such as vascular occlusions, by ablating calcified plaques in a vessel of a vascular system. The ultrasonic catheter system includes an ultrasonic vibration source configured to generate a vibratory motion, which is coupled to a portion of the ultrasonic catheter.

[0003] In particular, the ultrasound catheter has a catheter sheath with an inner cavity, and has an ultrasound transmission member movably arranged in the inner cavity of the catheter sheath. The ultrasound transmission member has a proximal portion coupled to an ultrasonic vibration source via an ultrasonic transducer, and the ultrasonic transducer transmits the vibration motion to the ultrasound transmission member. The distal portion of the ultrasound transmission member can be exposed from the catheter sheath. In operation, the distal portion is excited by ultrasonic waves generated by the ultrasonic transducer, thereby generating longitudinal and transverse mechanical vibrations at the distal portion of the ultrasound transmission member of the ultrasound catheter, which in turn ablates calcified lesions in the blood vessel.

[0004] What is needed in the art is an apparatus and method for locating, tracking, and displaying the position of a medical ultrasound object, such as an ultrasound catheter, during a medical procedure utilizing an ultrasound imaging system. Summary of the invention

[0005] The present invention provides an apparatus and method for locating and tracking a medical ultrasound object in a patient using ultrasound imaging during a medical procedure and displaying the position of the medical ultrasound object on a display screen of an ultrasound imaging system.

[0006] In one form, the present invention relates to a vascular occlusion treatment system, which includes an ultrasound imaging system and an ultrasound vibration system. The ultrasound imaging system has an imaging control circuit that is communicatively coupled to each of an ultrasound imaging probe and a display screen. The ultrasound imaging system is configured to generate an ultrasound image for display on a display screen based on ultrasound imaging data collected from an ultrasound imaging space. The ultrasound vibration system has an ultrasound generator that is operably coupled to an ultrasound catheter. The ultrasound catheter has a core wire with a distal tip. The ultrasound generator has a generator control circuit that is configured to alternately switch between an ultrasound operating frequency and a tracking frequency. The generator control circuit is communicatively coupled to the imaging control circuit. The generator control circuit is configured to execute program instructions to send a notification to the imaging control circuit when the generator control circuit has switched from the ultrasound operating frequency to the tracking frequency. The imaging control circuit is configured to respond to the notification by executing the following program instructions: initiating a search in the ultrasound imaging space to locate the distal tip of the core wire of the ultrasound catheter that is vibrating at the tracking frequency, and indicating the position of the distal tip in the ultrasound image displayed on the display screen.

[0007] In another form, the present invention relates to a method for tracking a medical ultrasound object using an ultrasound imaging system having an ultrasound imaging probe and a display screen, the ultrasound imaging probe generating ultrasound imaging data in an ultrasound imaging space for generating an ultrasound image for display on the display screen. The method includes: alternatingly vibrating the medical ultrasound object at an ultrasound operating frequency and a tracking frequency, the ultrasound operating frequency and the tracking frequency being different frequencies; notifying the ultrasound imaging system of a change from the ultrasound operating frequency to the tracking frequency; initiating a search by the ultrasound imaging system to search in the ultrasound imaging space to locate the medical ultrasound object being vibrated at the tracking frequency; and indicating a position of the medical ultrasound object in the ultrasound image displayed on the display screen.

[0008] In another form, the present invention relates to a method for locating the distal tip of an ultrasound catheter used in conjunction with an ultrasound imaging system having an ultrasound imaging probe and a display screen, the ultrasound imaging probe generating ultrasound imaging data in an ultrasound imaging space for generating an ultrasound image for display on the display screen. The method includes: establishing an ultrasound operating frequency of the distal tip of the core wire of the ultrasound catheter; establishing a tracking frequency of the distal tip of the core wire of the ultrasound catheter that is different from the ultrasound operating frequency; alternating the operation of the ultrasound catheter between vibrating the distal tip at the ultrasound operating frequency and vibrating the distal tip at the tracking frequency; notifying the ultrasound imaging system that the operation of the ultrasound catheter is changed from the ultrasound operating frequency to the tracking frequency; in response to the notification, initiating a search by the ultrasound imaging system to locate the distal tip of the core wire of the ultrasound catheter that is vibrating at the tracking frequency in the ultrasound imaging space; and indicating the position of the distal tip of the core wire of the ultrasound catheter in the ultrasound image displayed on the display screen.

[0009] In another form, the present invention relates to an alternative vascular occlusion treatment system, wherein an ultrasonic generator may have a generator control circuit configured to alternately switch between an output power level for treatment and an output power level for image tracking while maintaining the same ultrasonic frequency. The generator output power level for treatment can transmit strong vibration energy into the catheter and cause the distal portion of the catheter of the core wire (i.e., the active portion) to vibrate strongly at the ultrasonic frequency. The generator output power level for image tracking can transmit relatively small energy into the ultrasonic catheter and cause the distal portion of the core wire (i.e., the active portion) to vibrate, but without any therapeutic effect. The generator control circuit is communicatively coupled to the imaging control circuit. The generator control circuit is configured to execute program instructions to send a notification to the imaging control circuit when the generator control circuit has switched from the treatment power level to the image tracking power level. The imaging control circuit is configured to respond to the notification by executing program instructions to initiate a search in the ultrasound imaging space using the Doppler function. The Doppler function will only detect any moving components in the ultrasound imaging space. Therefore, the ultrasound imaging system will be able to detect the vibration of the distal portion (i.e., the active portion) of the core wire of the ultrasound catheter. After active averaging and filtering, the position of the distal tip of the core wire in the ultrasound image displayed on the display screen of the ultrasound imaging system will be displayed.

[0010] An advantage of the present invention is that the apparatus and method of the present invention do not require a separate tracking field generation system to generate a separate tracking field for locating a medical object in a patient. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other features and advantages of the present invention and the manner in which they are achieved will become more apparent, and the present invention will be better understood, by referring to the following description of the embodiments of the present invention in conjunction with the accompanying drawings, in which:

[0012] Figure 1 is a circuit block diagram of a vascular occlusion treatment system including an ultrasound imaging system and an ultrasound vibration system, the vascular occlusion treatment system being configured to locate and track a medical ultrasound subject.

[0013] Figure 2 yes Figure 1 Graphic depiction of use of a vascular occlusion therapy system in positioning and tracking a medical ultrasound object during a vascular occlusion therapy procedure.

[0014] Figure 3 is used Figure 1 A flow chart of a method for a vascular occlusion treatment system to locate and / or track a medical ultrasound object.

[0015] Corresponding reference characters indicate corresponding parts throughout the several views.The examples set out herein illustrate embodiments of the invention, and these examples should not be construed in any way as limiting the scope of the invention. DETAILED DESCRIPTION

[0016] Referring now to the drawings, and more particularly to Figure 1 , a vascular occlusion treatment system 10 according to an embodiment of the present invention is shown. The vascular occlusion treatment system 10 includes an ultrasound imaging system 12 and an ultrasound vibration system 14.

[0017] The ultrasound imaging system 12 includes an ultrasound console 16 that is communicatively coupled to an ultrasound imaging probe 18, such as by a flexible communication cable 20, such as a cable (multi-wire). The ultrasound console 16 includes imaging control circuitry 22 and a display screen 24. The imaging control circuitry 22 is communicatively coupled to each of the ultrasound imaging probe 18 and the display screen 24, such as by respective wired connections 26, 28. Also refer to Figure 2 The ultrasound imaging system 12 is configured to generate an ultrasound image 60 based on ultrasound imaging data collected from an ultrasound imaging space 30 defined by the ultrasound imaging probe 18 for display on the display screen 24. For example, in one embodiment, the ultrasound imaging space 30 may be represented by three-dimensional (3D) imaging data, and the ultrasound image may be a two-dimensional (2D) ultrasound image or a 3D ultrasound image.

[0018] The ultrasound imaging probe 18 includes a probe housing 18-1 and an ultrasound transducer array 18-2. The ultrasound transducer array 18-2 can be configured as a transceiver that is communicatively coupled to the imaging control circuit 22, for example, via a wired connection. The ultrasound transducer array 18-2 is mounted, for example, housed in the probe housing 18-1, and defines an ultrasound imaging space 30 as an ultrasound volume extending from the probe housing 18-1 along the Z-axis 18-3. The ultrasound transducer array 18-2 generates two-dimensional (2D) ultrasound slice data within the ultrasound field of view volume of the ultrasound imaging space 30, wherein a plurality of sequential 2D ultrasound data slices can be merged (e.g., stitched together) to form a 3D data set with 3D imaging data. In the present embodiment, in order to generate a 3D data set, the ultrasound transducer array 18-2 of the ultrasound imaging probe 18 can be a two-dimensional (2D) matrix of piezoelectric elements that are electronically scanned in a sweeping motion. In this way, the ultrasound imaging space 30 includes a plurality of sequentially generated 2D ultrasound image slices. Alternatively, the ultrasound transducer array 18-2 of the ultrasound imaging probe 18 may be a mechanically movable one-dimensional (ID) linear array of piezoelectric elements that is mechanically scanned to produce a plurality of sequentially generated ultrasound image slices. As another alternative, if desired, the ultrasound transducer array 18-2 may be a fixed position linear array (i.e., fixed relative to the probe housing 18-1) that generates a single ultrasound image slice (periodically refreshed), in which case the ultrasound imaging space 30 is narrowed to the thickness of a single ultrasound image slice.

[0019] In the present embodiment, the imaging control circuit 22 is a circuit with data processing capabilities and command generation capabilities for processing the imaging data generated by the ultrasound imaging probe 18 and generating an ultrasound image for display on the display screen 24. In the present embodiment, the imaging control circuit 22 has a microprocessor 22-1 and an associated non-transitory electronic memory 22-2, as well as an input / output (I / O) circuit. As will be appreciated by those skilled in the art, the microprocessor 22-1 and the associated non-transitory electronic memory 22-2 are commercially available components. As is known in the art, the microprocessor 22-1 can be in the form of a single microprocessor or two or more parallel microprocessors. The non-transitory electronic memory 22-2 can include multiple types of digital data storage, such as random access memory (RAM), non-volatile RAM (NVRAM), read-only memory (ROM) and / or electrically erasable programmable read-only memory (EEPROM). The non-transitory electronic memory 22-2 can also include one or more of the above-mentioned electronic memory forms, or mass data storage on a computer hard drive or optical disk. Alternatively, the imaging control circuit 22 can be assembled as one or more application-specific integrated circuits (ASICs).

[0020] refer to Figure 1 and Figure 2 , the ultrasound imaging space 30 may be represented by three-dimensional (3D) imaging data generated and stored in the non-transitory electronic memory 22-2 of the imaging control circuit 22. The imaging control circuit 22 processes program instructions received from a program source such as software or firmware, and ultrasound imaging data received from the ultrasound imaging probe 18 and / or previously stored in the non-transitory electronic memory 22-2 to which the imaging control circuit 22 has electronic access, to generate an ultrasound image 60 (see Figure 2 ) for display on the display screen 24. In other words, the imaging control circuit 22 generates an ultrasound image 60 for display on the display screen 24 based on ultrasound imaging data collected from the ultrasound imaging space 30, wherein the ultrasound imaging data has been generated and stored by the ultrasound transducer array 18-2 of the ultrasound imaging probe 18 and stored in the non-transitory electronic memory 22-2.

[0021] The display screen 24 may be or form part of a graphical user interface, wherein the display screen 24 is a touch screen that accommodates user input and displays an ultrasound image formed by 2D ultrasound slice data provided by the ultrasound imaging probe 18 within a 3D imaging volume of the ultrasound imaging space 30. The display screen 24 may be configured as a standard 2D display, or alternatively, may be configured as a 3D display. For example, a 3D data set captured by the ultrasound imaging system 12 may be presented to the user via an autostereoscopic or other display method that presents a 3D image to the user. In this way, the display screen 24 may display the ultrasound image 60 as a 2D or 3D ultrasound image.

[0022] The ultrasonic vibration system 14 includes an ultrasonic generator 32, an ultrasonic transducer 34, and a medical ultrasound object 36. In the present example, the medical ultrasound object 36 is a vibrating device, such as a portion of an ultrasonic catheter.

[0023] The ultrasonic generator 32 is operably coupled to the medical ultrasound object 36 via the ultrasonic transducer 34. More specifically, the ultrasonic generator 32 is communicatively coupled to the ultrasonic transducer 34 via a communication cable 38 such as a multi-wire cable. The ultrasonic generator 32 is configured to generate an electrical signal at an ultrasonic frequency, which in turn is provided to the ultrasonic transducer 34 via the communication cable 38. The ultrasonic transducer 34, such as an acoustic horn, converts the ultrasonic electrical signal received from the ultrasonic generator 32 into a mechanical vibration wave. The ultrasonic transducer 34 is mechanically and / or acoustically coupled to the medical ultrasound object 36 so as to transmit the ultrasonic vibration wave to the medical ultrasound object 36.

[0024] The ultrasonic generator 32 includes a generator control circuit 40. The generator control circuit 40 is a circuit with data processing capabilities and command generation capabilities. In the present embodiment, the generator control circuit 40 has a microprocessor 40-1 and an associated non-transient electronic memory 40-2, as well as an input / output (I / O) circuit. As will be appreciated by those skilled in the art, the microprocessor 40-1 and the associated non-transient electronic memory 40-2 are commercially available components. As known in the art, the microprocessor 40-1 can be in the form of a single microprocessor or two or more parallel microprocessors. The non-transient electronic memory 40-2 can include multiple types of digital data storage, such as random access memory (RAM), non-volatile RAM (NVRAM), read-only memory (ROM) and / or electrically erasable programmable read-only memory (EEPROM). The non-transient electronic memory 40-2 can also include one or more of the above-mentioned electronic memory forms, or mass data storage on a computer hard drive or optical disk. Alternatively, the generator control circuit 40 can be assembled as one or more application-specific integrated circuits (ASICs).

[0025] The generator control circuit 40 is connected to the power supply 41 via a communication link 42 (such as a wired cable) or alternatively through a wireless interface operating with a short-range wireless protocol (such as ), communicatively coupled to the imaging control circuit 22.

[0026] The generator control circuit 40 is configured to operate the ultrasonic generator 32 to generate a variable ultrasonic electrical signal, wherein the operating frequency of the ultrasonic signal alternately switches between an ultrasonic operating frequency and a tracking frequency different from the ultrasonic operating frequency. More specifically, the generator control circuit 40 processes program instructions received from a program source such as software or firmware, to which the generator control circuit 40 has electronic access, so as to operate the ultrasonic generator 32 to generate a variable ultrasonic electrical signal at a plurality of ultrasonic operating frequencies (i.e., at least one ultrasonic operating frequency and a tracking frequency different from the ultrasonic operating frequency). The generator control circuit 40 also executes the program instructions to send a notification (e.g., a switch bit or a message packet) to the imaging control circuit 22 via the communication link 42 when the generator control circuit 40 has switched the operating frequency of the ultrasonic electrical signal generated by the ultrasonic generator 32 from the ultrasonic operating frequency to the tracking frequency.

[0027] In the present exemplary embodiment, the ultrasound operating frequency may be, for example, an operating frequency in the frequency range of about 20 kilohertz (kHz) to about 40 kHz, and the tracking frequency is a different operating frequency that affects the vibration velocity of the medical ultrasound object 36 (e.g., the distal tip of the elongated ultrasound core wire) in the range of about 1 cm per second to about 500 cm per second. In some embodiments, it may be desirable for the tracking frequency to be lower than the ultrasound operating frequency, while in other embodiments, it may be desirable for the tracking frequency to be higher than the ultrasound operating frequency.

[0028] As used herein, the term "about" refers to the indicated amount of the indicated unit, plus or minus 10%.

[0029] Each operating frequency, namely the ultrasonic working frequency and the tracking frequency, is alternately generated by the ultrasonic generator 32 and further coupled to the medical ultrasonic object 36 via the ultrasonic transducer 34. In the present embodiment, the medical ultrasonic object 36 may be a vibrating portion of the ultrasonic catheter 44.

[0030] For example, refer to Figure 1 and Figure 2 , the ultrasonic catheter 44 has a catheter sheath 46 and a core wire 48. The catheter sheath 46 has a proximal end 46-1, a distal end 46-2, and a lumen 46-3 extending longitudinally between the proximal end 46-1 and the distal end 46-2. The core wire 48 is movably disposed in the lumen 46-3 of the catheter sheath 46. The core wire 48 can be formed as an integral elongated member made of a flexible metal such as nitinol to serve as an ultrasonic transmission member.

[0031] The core wire 48 has a proximal portion 48-1, a distal portion 48-2, and a distal tip 48-3. The proximal portion 48-1 of the core wire 48 is mechanically and / or acoustically coupled to the ultrasonic generator 32 via the ultrasonic transducer 34, so that the ultrasonic transducer 34 transmits the vibration motion to the core wire 48, more specifically, to the distal portion 48-2 of the core wire 48. The distal portion 48-2 of the core wire 48 can be exposed from the distal end 46-2 of the catheter sheath 46, such as, for example, in the range of 5 millimeters (mm) to 200 mm, wherein the exposed distal portion 48-2 of the core wire 48 is referred to herein as an active portion having a distal tip 48-3.

[0032] refer to Figure 2, a graphical representation of a portion of a patient 50 (e.g., a portion of a leg) having tissue 52 is shown, through which a blood vessel 54 extends. A calcified occlusion 56 is located in the blood vessel 54. The ultrasonic catheter 44 is inserted into the blood vessel 54 via an introducer cannula 58. During the occlusion removal procedure, the distal portion 48-2 of the core wire 48 engages the calcified occlusion 56. The distal portion 48-2 of the core wire 48 is excited at the ultrasonic operating frequency by ultrasonic waves generated by the ultrasonic transducer 34, which in turn generates longitudinal and transverse mechanical vibrations at the distal portion 48-2 of the core wire 48. The longitudinal and transverse mechanical vibrations at the distal portion 48-2 of the core wire 48, including the distal tip 48-3, ablate the calcified occlusion 56 in the blood vessel 54 of the patient 50.

[0033] In order to locate and track the position of the medical ultrasound object 36, such as the distal tip 48-3 of the core wire 48, the generator control circuit 40 alternately switches between the ultrasound operating frequency and the tracking frequency, wherein the tracking frequency is different from the ultrasound operating frequency. The generator control circuit 40 executes program instructions to send a notification (e.g., a switching bit or a message packet) to the imaging control circuit 22 of the ultrasound imaging system 12 when the generator control circuit 40 switches the operating frequency of the ultrasound electrical signal generated by the ultrasound generator 32 from the ultrasound operating frequency to the tracking frequency. The imaging control circuit 22 of the ultrasound imaging system 12 is configured to respond to the notification by executing program instructions to initiate a search in the ultrasound imaging space 30, i.e., the associated 3D imaging data, to locate the distal tip 48-3 of the core wire 48 of the ultrasound catheter 44 that is vibrating at the tracking frequency, and once located, indicate the position of the distal tip 48-3 in the ultrasound image 60 displayed on the display screen 24. The action of indicating the position of the distal tip 48-3 in the ultrasound image 60 displayed on the display screen 24 can be achieved by the imaging control circuit 22 executing program instructions to highlight a portion of the ultrasound image 60 displayed on the display screen 24, represented by the diamond 62, which corresponds to the distal tip 48-3 of the core wire 48 of the ultrasound catheter 44. As used herein, "highlighting" means providing a contrasting color or brightness relative to the brightness and / or color of the ultrasound image 60.

[0034] The generator control circuit 40 may periodically alternate between the ultrasonic operating frequency and the tracking frequency, for example in a continuous loop, wherein the time ratio of the ultrasonic operating frequency to the tracking frequency may be in the range of 80:20 to 95:5. For example, the duration of the ultrasonic operating frequency may be at least four times longer than the duration of the tracking frequency, so that the duration of the tracking frequency does not adversely affect the occlusion removal performance of the distal tip 48-3 of the core wire 48. Moreover, the switching between the ultrasonic operating frequency and the tracking frequency may occur at a switching frequency of about 1 Hz to about 1000 Hz. At the end of the tracking frequency duration, the generator control circuit 40 executes the program instructions to switch back to the ultrasonic operating frequency. In addition, the generator control circuit 40 may execute the program instructions as a continuous loop, repeating each action of switching to the tracking frequency, sending a notification, and switching back to the ultrasonic operating frequency at a set or variable repetition frequency, wherein the repetition frequency may be in the range of about 1 Hz to about 1000 Hz.

[0035] refer to Figure 3 , a flow chart of a method for locating and / or tracking a medical ultrasound object 36 using an ultrasound imaging system 12 having an ultrasound imaging probe 18 and a display screen 24 is shown. As described more fully above, the ultrasound imaging probe 18 generates ultrasound imaging data in an ultrasound imaging space 30 for generating an ultrasound image 60 for display on the display screen 24.

[0036] At step S100, the medical ultrasound object 36 is vibrated alternately at an ultrasonic operating frequency and a tracking frequency, wherein the ultrasonic operating frequency and the tracking frequency are different frequencies. Each of the ultrasonic operating frequency and the tracking frequency is predetermined and can be established in the non-transitory electronic memory 40-2 of the generator control circuit 40 for reference. The medical ultrasound object 36 can be, for example, the distal tip 48-3 of the core wire 48 carried by the ultrasound catheter 44, or the distal portion 48-2 including the distal tip 48-3 of the core wire 48. For example, at step S100, the operation of the ultrasound catheter 44 alternates between vibrating the distal tip 48-3 at the ultrasonic operating frequency and vibrating the distal tip 48-3 at the tracking frequency.

[0037] The ultrasound operating frequency may be an operating frequency in the range of about 20 kHz to about 40 kHz generated by the ultrasound generator 32, and the tracking frequency may be an operating frequency of a vibration velocity in the range of about 1 cm per second to about 500 cm per second that affects the medical ultrasound object 36 generated by the ultrasound generator 32. The tracking frequency may be higher than the ultrasound operating frequency, or the tracking frequency may be lower than the ultrasound operating frequency.

[0038] The time ratio of the ultrasonic operating frequency to the tracking frequency is in the range of 80:20 to 95:5, wherein after a predetermined duration of the tracking frequency, the operating frequency of the ultrasonic generator 32 is switched back to the ultrasonic operating frequency. After a predetermined duration of the tracking frequency, the method switches back to the ultrasonic operating frequency. The action of alternating vibration at step S100 alternately switches between the ultrasonic operating frequency and the tracking frequency at a switching frequency of about 1 Hz to about 1000 Hz.

[0039] At step S102, the ultrasound imaging system 12 is notified of the change from the ultrasound operating frequency to the tracking frequency. In particular, the generator control circuit 40 executes program instructions to send a notification (e.g., a switching bit or a message packet) to the imaging control circuit 22 of the ultrasound imaging system 12 when the generator control circuit 40 switches the operating frequency of the ultrasound electrical signal generated by the ultrasound generator 32 from the ultrasound operating frequency to the tracking frequency.

[0040] At step S104 , in response to the notification at step S102 , the ultrasound imaging system 12 initiates a search in the ultrasound imaging space 30 using imaging data generated and collected by the ultrasound imaging probe 18 to locate the medical ultrasound object 36 vibrating at the tracking frequency.

[0041] For example, assume that the medical ultrasound object 36 is a distal portion 48-2 having a distal tip 48-3 of a core wire 48 of an ultrasound catheter 44. In response to the notification, a search is initiated by the ultrasound imaging system 12 to locate the distal tip 48-3 of the core wire 48 of the ultrasound catheter 44 that is vibrating at the tracking frequency in the ultrasound imaging space 30. For example, assume that the tracking frequency is selected to affect the medical ultrasound object 36 (e.g., the distal tip 48-3) at a vibration speed of approximately 50 centimeters per second. In such a case, for example, the imaging control circuit 22 can call a Doppler function to search the imaging data set associated with the ultrasound imaging space 30 to identify an object that is vibrating at a speed of approximately or exactly 50 centimeters per second, so as to determine the location within the ultrasound imaging space 30 where the vibration occurs at the vibration speed associated with the tracking frequency.

[0042] As a further refinement of the search, in some implementations, the ultrasound imaging system 12 may take into account the shape of the medical ultrasound object 36 in conjunction with positioning the object to track frequency vibrations.

[0043] At step S106, the position of the medical ultrasound object 36 is indicated in the ultrasound image 60 displayed on the display screen 24. The ultrasound image 60 may be, for example, a 2D ultrasound image or a 3D ultrasound image. Figure 2, the action of indicating the position of the distal tip 48-3 in the ultrasound image 60 displayed on the display screen 24 can be achieved by the imaging control circuit 22 executing program instructions to highlight a portion of the ultrasound image 60 represented by a diamond 62 displayed on the display screen 24, which portion of the ultrasound image 60 corresponds to the medical ultrasound object 36, for example, the distal tip 48-3 of the core wire 48 of the ultrasound catheter 44.

[0044] If the medical ultrasound object 36, for example, the distal tip 48-3 of the core wire 48 of the ultrasound catheter 44, is not positioned within the ultrasound imaging space 30 of the ultrasound imaging probe 18, then the ultrasound image 60 displayed on the display screen 24 will not indicate the current position of the medical ultrasound object 36. To correct this situation, the user will move the ultrasound imaging probe 18 relative to the patient 50 until the medical ultrasound object 36 is positioned within the ultrasound imaging space 30 of the ultrasound imaging probe 18. Once the medical ultrasound object 36 is positioned within the ultrasound imaging space 30, the current position of the medical ultrasound object 36 relative to the patient 50 will be indicated in the ultrasound image 60 displayed on the display screen 24.

[0045] Once the location of the medical ultrasound object 36 is identified, the location of the medical ultrasound object 36 may be tracked by observing the movement of a highlighted portion represented by a diamond 62 of an ultrasound image 60 displayed on the display screen 24 that corresponds to the medical ultrasound object 36 .

[0046] As an alternative to the above-described method and apparatus, the generator control circuit 40 of the ultrasonic generator 32 can be configured to alternately switch between an output power level for treatment and an output power level for image tracking while using the same ultrasonic frequency. The generator output power level for treatment can transmit strong vibration energy into the ultrasonic catheter 44 and cause the distal portion 48-2 (i.e., the active portion) of the core wire 48 to vibrate strongly at the ultrasonic frequency. The generator output power level for image tracking can transmit relatively small energy into the ultrasonic catheter 44 and cause the distal portion 48-2 (i.e., the active portion) of the core wire 48 to vibrate, but without any therapeutic effect. The generator control circuit 40 is communicatively coupled to the imaging control circuit 22. The generator control circuit 40 is configured to execute program instructions to send a notification to the imaging control circuit 22 when the generator control circuit 40 has switched from the treatment power level to the image tracking power level. The imaging control circuit 22 is configured to respond to the notification by executing program instructions to initiate a search in the ultrasound imaging space 30 using the Doppler function. The Doppler function will detect only any moving components in the ultrasound imaging space 30. Therefore, the vibration of the distal portion 48-2 (i.e., the active portion) of the core wire 48 of the ultrasound catheter 44 will be detectable by the ultrasound imaging system 12. After active averaging and filtering, the position of the distal tip 48-3 of the core wire 48 will be displayed in the ultrasound image displayed on the display screen 24 of the ultrasound imaging system 12, for example, by highlighting indicated by diamond 62.

[0047] The following also relate to the present invention:

[0048] In one form, the present invention relates to a vascular occlusion treatment system, which includes an ultrasound imaging system and an ultrasound vibration system. The ultrasound imaging system has an imaging control circuit that is communicatively coupled to each of an ultrasound imaging probe and a display screen. The ultrasound imaging system is configured to generate an ultrasound image for display on a display screen based on ultrasound imaging data collected from an ultrasound imaging space. The ultrasound vibration system has an ultrasound generator that is operably coupled to an ultrasound catheter. The ultrasound catheter has a core wire with a distal tip. The ultrasound generator has a generator control circuit that is configured to alternately switch between an ultrasound operating frequency and a tracking frequency, wherein the ultrasound operating frequency and the tracking frequency may be different frequencies. The generator control circuit is communicatively coupled to the imaging control circuit. The generator control circuit is configured to execute program instructions to send a notification to the imaging control circuit when the generator control circuit has switched from the ultrasound operating frequency to the tracking frequency. The imaging control circuit is configured to respond to the notification by executing the following program instructions: initiating a search in the ultrasound imaging space to locate the distal tip of the core wire of the ultrasound catheter that is vibrating at the tracking frequency, and indicating the position of the distal tip in the ultrasound image displayed on the display screen.

[0049] The ultrasound imaging system may be configured to represent the ultrasound imaging space by 3D imaging data, and the ultrasound image may be a 2D ultrasound image or a 3D ultrasound image. The time ratio of the ultrasound operating frequency to the tracking frequency may be about 80:20 to 95:5. Optionally, after a predetermined duration of the tracking frequency, the generator control circuit executes a program instruction to switch back to the ultrasound operating frequency. The generator control circuit may execute a program instruction to switch between the ultrasound operating frequency and the tracking frequency at a switching frequency of about 1 Hz to about 1000 Hz. More specifically, the generator control circuit may execute a program instruction to repeat the actions of switching to the tracking frequency, sending a notification, and switching back to the ultrasound operating frequency at a repetition frequency of about 1 Hz to about 1000 Hz. The tracking frequency may affect the vibration velocity of the distal tip of the ultrasound catheter, which ranges from about 1 cm per second to about 500 cm per second. The tracking frequency may be higher than the ultrasound operating frequency. Alternatively, the tracking frequency may be lower than the ultrasound operating frequency. The imaging control circuitry may be configured to indicate the location of the distal tip in an ultrasound image displayed on the display screen by executing program instructions to highlight a portion of the ultrasound image displayed on the display screen, the portion of the ultrasound image corresponding to the distal tip of the core wire of the ultrasound catheter.

[0050] In another form, the present invention relates to a method, for example, for operating a medical device, using an ultrasound imaging system having an ultrasound imaging probe and a display screen to track a medical ultrasound object, the ultrasound imaging probe generating ultrasound imaging data in an ultrasound imaging space for generating an ultrasound image for display on the display screen. The method includes: vibrating the medical ultrasound object alternately at an ultrasound operating frequency and a tracking frequency, the ultrasound operating frequency and the tracking frequency being different frequencies; notifying the ultrasound imaging system of a change from the ultrasound operating frequency to the tracking frequency; initiating a search by the ultrasound imaging system to search in the ultrasound imaging space to locate the medical ultrasound object being vibrated at the tracking frequency; and indicating the position of the medical ultrasound object in the ultrasound image displayed on the display screen.

[0051] The medical ultrasound object may be the distal tip of a core wire carried by an ultrasound catheter. The ultrasound imaging space may be represented by 3D imaging data, and the ultrasound image may be a 2D ultrasound image or a 3D ultrasound image. The time ratio of the ultrasound operating frequency to the tracking frequency may be about 80:20 to 95:5. Optionally, after a predetermined duration of the tracking frequency, the method includes switching back to the ultrasound operating frequency. The alternating vibration action may include switching between the ultrasound operating frequency and the tracking frequency at a switching frequency of about 1 Hz to about 1000 Hz. The alternating vibration action may include repeatedly switching to the tracking frequency, notifying, and switching back to the ultrasound operating frequency at a repetition frequency of about 1 Hz to about 1000 Hz. The tracking frequency may affect the vibration speed of the medical ultrasound object, which ranges from about 1 cm per second to about 500 cm per second. The tracking frequency may be higher than the ultrasound operating frequency. Alternatively, the tracking frequency may be lower than the ultrasound operating frequency. The indicating action may include highlighting a portion of an ultrasound image displayed on a display screen, which portion of the ultrasound image is for the medical ultrasound object.

[0052] In another form, the present invention relates to a method, such as for operating a medical device, to locate the distal tip of an ultrasound catheter used in conjunction with an ultrasound imaging system having an ultrasound imaging probe and a display screen, the ultrasound imaging probe generating ultrasound imaging data in an ultrasound imaging space for generating an ultrasound image for display on the display screen. The method includes establishing an ultrasound operating frequency of the distal tip of the core wire of the ultrasound catheter; establishing a tracking frequency of the distal tip of the core wire of the ultrasound catheter that is different from the ultrasound operating frequency; alternating the operation of the ultrasound catheter between vibrating the distal tip at the ultrasound operating frequency and vibrating the distal tip at the tracking frequency; notifying the ultrasound imaging system that the operation of the ultrasound catheter is changed from the ultrasound operating frequency to the tracking frequency; in response to the notification, initiating a search by the ultrasound imaging system to locate the distal tip of the core wire of the ultrasound catheter that is vibrating at the tracking frequency in the ultrasound imaging space; and indicating the position of the distal tip of the core wire of the ultrasound catheter in the ultrasound image displayed on the display screen.

[0053] The ultrasound imaging space can be represented by 3D imaging data, and the ultrasound image can be a 2D ultrasound image or a 3D ultrasound image. The time ratio of the ultrasound operating frequency to the tracking frequency is optionally in the range of 80:20 to 95:5. Optionally, after a predetermined duration of the tracking frequency, the method includes switching back to the ultrasound operating frequency. The action of alternatingly operating the ultrasound catheter may include switching from the ultrasound operating frequency to the tracking frequency at a switching frequency of about 1 Hz to about 1000 Hz.

[0054] The action of alternatingly operating the ultrasonic catheter may include repeatedly switching to the tracking frequency, notifying, and switching back to the ultrasonic operating frequency at a repetition frequency of about 1 Hz to about 1000 Hz. The tracking frequency may affect the vibration speed of the distal tip of the ultrasonic catheter, which ranges from about 1 cm per second to about 500 cm per second. The tracking frequency may be higher than the ultrasonic operating frequency. Alternatively, the tracking frequency may be lower than the ultrasonic operating frequency. The action of indicating may include highlighting a portion of an ultrasonic image displayed on a display screen, the portion of the ultrasonic image corresponding to the distal tip of the core wire of the ultrasonic catheter.

[0055] In another form, the present invention relates to an alternative vascular occlusion treatment system. The system includes an ultrasound imaging system and an ultrasound vibration system. The ultrasound imaging system has an imaging control circuit that is communicatively coupled to each of an ultrasound imaging probe and a display screen. The ultrasound imaging system is configured to generate an ultrasound image for display on the display screen based on ultrasound imaging data collected from an ultrasound imaging space. The ultrasound vibration system has an ultrasound generator that is operably coupled to an ultrasound catheter. The ultrasound catheter has a core wire with a distal portion, the distal portion having a distal tip. The ultrasound generator has a generator control circuit that is configured to alternately switch between an output power level for treatment and an output power level for image tracking while maintaining the same ultrasound frequency. The generator control circuit is communicatively coupled to the imaging control circuit. The generator control circuit is configured to execute program instructions to send a notification to the imaging control circuit when the generator control circuit has switched from a treatment power level to an image tracking power level. The imaging control circuit is configured to respond to the notification by executing the following program instructions: initiating a search in the ultrasound imaging space using a Doppler function to detect any moving components in the ultrasound imaging space; and indicating the position of the distal tip in the ultrasound image displayed on the display screen.

[0056] The ultrasound imaging system may be configured to represent the ultrasound imaging space by 3D imaging data, and the ultrasound image may be a 2D ultrasound image or a 3D ultrasound image. The imaging control circuit may be configured to indicate the position of the distal tip in the ultrasound image displayed on the display screen by executing program instructions to highlight a portion of the ultrasound image displayed on the display screen, the portion of the ultrasound image corresponding to the distal tip of the core wire of the ultrasound catheter.

[0057] Although the present invention has been described for at least one embodiment, the present invention can be further modified within the spirit and scope of the present disclosure. Therefore, the present application is intended to cover any variation, use or modification of the present invention using its general principles. In addition, the present application is intended to cover such deviations from the present disclosure that fall into the known or customary practices in the field to which the present invention belongs and fall within the limitations of the appended claims.

Claims

1. A vascular occlusion treatment system, comprising: an ultrasound imaging system having imaging control circuitry communicatively coupled to each of an ultrasound imaging probe and a display screen, the ultrasound imaging system being configured to generate an ultrasound image for display on the display screen based on ultrasound imaging data collected from an ultrasound imaging space; and An ultrasonic vibration system having an ultrasonic generator operably coupled to an ultrasonic catheter having a core wire with a distal tip, the ultrasonic generator having a generator control circuit configured to alternately switch between an ultrasonic operating frequency and a tracking frequency, the generator control circuit being communicatively coupled to the imaging control circuit, wherein the tracking frequency is higher than the ultrasonic operating frequency, the generator control circuit being configured to execute program instructions to send a notification to the imaging control circuit when the generator control circuit has switched from the ultrasound operating frequency to the tracking frequency; The imaging control circuit is configured to respond to the notification by executing the following program instructions: initiating a search for a tracking frequency in the ultrasound imaging space to locate a distal tip of a core wire of the ultrasound catheter that is vibrating at the tracking frequency, wherein initiating the search for the tracking frequency includes the imaging control circuit invoking a Doppler function to search an imaging data set associated with the ultrasound imaging space to identify an object that is vibrating at approximately or exactly the vibration velocity of the distal tip; as well as A position of the distal tip in the ultrasound image displayed on the display screen is indicated.

2. The vascular occlusion treatment system according to claim 1, wherein: The ultrasound imaging space is represented by 3D imaging data, and the ultrasound image is a 2D ultrasound image or a 3D ultrasound image.

3. The vascular occlusion treatment system according to any one of claims 1 to 2, wherein: A time ratio of the ultrasonic operating frequency to the tracking frequency is in a range of 80:20 to 95:

5.

4. The vascular occlusion treatment system according to any one of claims 1 to 2, wherein: After a predetermined duration of the tracking frequency, the generator control circuit executes program instructions to switch back to the ultrasonic operating frequency.

5. The vascular occlusion treatment system according to any one of claims 1 to 2, wherein: The generator control circuit executes program instructions to switch between the ultrasonic operating frequency and the tracking frequency at a switching frequency of about 1 Hz to about 1000 Hz.

6. The vascular occlusion treatment system according to any one of claims 1 to 2, wherein: The generator control circuit executes program instructions to repeat the actions of switching to the tracking frequency, sending the notification, and switching back to the ultrasonic operating frequency at a repetition frequency of about 1 Hz to about 1000 Hz.

7. The vascular occlusion treatment system according to any one of claims 1 to 2, wherein: The tracking frequency affects a vibration velocity of the distal tip of the ultrasonic catheter in a range of about 1 centimeter per second to about 500 centimeters per second.

8. The vascular occlusion treatment system according to any one of claims 1 to 2, wherein: The action of indicating the position of the distal tip in the ultrasound image displayed on the display screen includes the imaging control circuit executing program instructions to highlight a portion of the ultrasound image displayed on the display screen, the portion of the ultrasound image corresponding to the distal tip of the core wire of the ultrasound catheter.

9. A vascular occlusion treatment system, comprising: an ultrasound imaging system having imaging control circuitry communicatively coupled to each of an ultrasound imaging probe and a display screen, the ultrasound imaging system being configured to generate an ultrasound image for display on the display screen based on ultrasound imaging data collected from an ultrasound imaging space; and an ultrasonic vibration system having an ultrasonic generator operably coupled to an ultrasonic catheter, the ultrasonic catheter having a core wire with a distal portion, the distal portion having a distal tip, the ultrasonic generator having a generator control circuit, the generator control circuit being configured to alternately switch between an output power level for treatment and an output power level for image tracking while maintaining the same ultrasonic frequency, the generator control circuit being communicatively coupled to the imaging control circuit, the generator control circuit being configured to execute program instructions to send a notification to the imaging control circuit when the generator control circuit has switched from the therapeutic power level to the image tracking power level, The imaging control circuit is configured to respond to the notification by executing the following program instructions: initiating a search in the ultrasound imaging space using a Doppler function to detect any moving components in the ultrasound imaging space, wherein initiating the search for the tracking frequency includes the imaging control circuit invoking the Doppler function to detect only any moving components within the ultrasound imaging space; and A position of the distal tip in the ultrasound image displayed on the display screen is indicated.

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