Patent Publication Number: US-2022233164-A1

Title: Ultrasound Probe

Description:
TECHNICAL FIELD 
     The following generally relates to ultrasound imaging and more particularly to an ultrasound probe, and is described with particular application to neurosurgery, and is amenable to other applications in which a probe head with a transducer is inserted into a natural or artificial cavity in a subject (e.g., human or animal) or an object (e.g., non-human/animal) to image a surface of the natural or artificial cavity. 
     BACKGROUND 
     Ultrasound imaging has provided useful information about the interior characteristics of an object or subject under examination. For example, intraoperative ultrasound imaging has been used in brain tumor surgery for detecting and localizing tumor remnants Unlike other imaging modalities, e.g. magnetic resonance imaging (MRI) and computed tomography (CT) in neurosurgery, ultrasound offers a real-time display of anatomy and/or function during a procedure. In one instance, the real-time display allows for determining a relevancy of a pre-operative navigation image. For instances, when a brain shift occurs the pre-operative image used by the navigation/tracking system may become obsolete and unusable to the surgeon for the procedure. In another example, the real-time display allows to detect a presence of blood, assess whether a vessel needs to be avoided or clipped, identify a functional area to avoid, etc. 
     However, ultrasound transducers in neurosurgery are designed for scanning from the top of the cavity, and not designed for reaching the bottom of the resection cavity, e.g., due to their bulk sizes. That is, the ultrasound probes do not carry a form factor that allows easy scanning onto the bottom of the resection cavity and keeps the surgeon line of sight. As a consequence, saline is added into the resection cavity for enabling acoustic coupling between the bottom of the resection zone and the transducer surface. Unfortunately, the introduction of saline into the procedure interrupts workflow as saline has to be added and then subsequently drained. In addition, the saline manifests as image brightness artifact, e.g., introduced from overcompensating the received signal due to a mismatch in attenuation coefficients between saline and brain tissue. 
     SUMMARY 
     Aspects of the application address the above matters, and others. 
     In one aspect, a system includes an ultrasound probe. The ultrasound probe includes a probe head, a handle, and an elongate shaft disposed between and coupling the probe head and the handle. The probe head houses a transducer array. The elongate shaft includes a first portion coupled to the probe head and a second portion coupled to the handle. The second portion includes a first end region coupled to the handle. The second portion further includes a second end region extending above the handle and coupled to the first portion such that a line of site from behind the probe to the probe head is visually unobstructed by the handle. 
     In another aspect, a method includes positioning a head of an ultrasound probe in a cavity within an object. The ultrasound probe includes a transducer array in the head, a handle, and an elongate shaft between the head and the handle. The elongate shaft includes a linear portion coupled to the head and a non-linear portion coupled to the handle. The non-linear portion protrudes above the handle and is coupled to the first portion such that a line of site from behind the probe to the head is visually unobstructed by the handle. The method further includes transmitting ultrasound signals with the transducer array. The method further includes receiving echo signals with the transducer array. The method further includes generating an image of an inside of the cavity based on the received echo signals. 
     In yet another aspect, an ultrasound system includes a console and an ultrasound probe in electrical communication with the console. The ultrasound probe includes a probe head that houses a transducer array, a handle; and an elongate shaft coupling the probe head and the handle. The elongate shaft positions the probe head above the handle so that a line of site from behind the probe to the probe head is visually unobstructed by the handle. 
     Those skilled in the art will recognize still other aspects of the present application upon reading and understanding the attached description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The application is illustrated by way of example and not limited by the figures of the accompanying drawings, in which like references indicate similar elements and in which: 
         FIG. 1  schematically illustrates an example ultrasound imaging system including a console and a probe, in accordance with an embodiment(s) herein; 
         FIG. 2  schematically illustrates an example of the probe, in accordance with an embodiment(s) herein; 
         FIG. 3  schematically illustrates an example of a rectangular shaped face, in accordance with an embodiment(s) herein; 
         FIG. 4  schematically illustrates another example of a rounded rectangular shaped face, in accordance with an embodiment(s) herein; 
         FIG. 5  schematically illustrates an example of a square shaped face, in accordance with an embodiment(s) herein; 
         FIG. 6  schematically illustrates another example of a rounded square shaped face, in accordance with an embodiment(s) herein; 
         FIG. 7  schematically illustrates an example of a circular shaped face, in accordance with an embodiment(s) herein; 
         FIG. 8  schematically illustrates another example of an elliptical square shaped face, in accordance with an embodiment(s) herein; 
         FIG. 9  schematically illustrates another example of the probe, in accordance with an embodiment(s) herein; 
         FIG. 10  schematically illustrates yet another example of the probe, in accordance with an embodiment(s) herein; 
         FIG. 11  schematically illustrates still another example of the probe, in accordance with an embodiment(s) herein; 
         FIG. 12  schematically illustrates another example of the ultrasound imaging system further including a tracking system, in accordance with an embodiment(s) herein; 
         FIG. 13  schematically illustrates an example method, in accordance with an embodiment(s) herein; 
         FIG. 14  schematically illustrates an example configuration for 3-D and/or 4-D imaging, in accordance with an embodiment(s) herein; 
         FIG. 15  schematically illustrates another example configuration for 3-D and/or 4-D imaging, in accordance with an embodiment(s) herein; and 
         FIG. 16  schematically illustrates still another example configuration for 3-D and/or 4-D imaging, in accordance with an embodiment(s) herein. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an example imaging system  102  such as an ultrasound imaging system/scanner. The imaging system  102  includes a probe  104  and a console  106 , which interface with each other through suitable complementary wireless interfaces  108  and  110  and/or hardware (e.g., cable connectors and a cable, etc.). With a wireless probe, the probe  104  can be placed on an instrument table next to an examination region, which can improve workflow efficiency and/or allow acquired data to be wirelessly transmitted to a computing device for processing. 
     The probe  104  includes a transducer array  114  with one or more transducer elements  116 . The one or more transducer elements  116  includes a capacitive micromachined ultrasonic transducer (cMUT), thick film print, piezoelectric-composite and/or other type of transducer material. In one instance, the transducer material provides optimal near-field image quality. In another instance, the transducer material is based on other criteria. The one or more transducer elements  116  are configured to convert an excitation electrical pulse into an ultrasound pressure field and convert a received ultrasound pressure field (an echo) into electrical (e.g., a radio frequency (RF)) signal. 
     The one or more transducer elements  116  is arranged as a 1-D or 2-D, linear, curved and/or otherwise shaped, fully populated or sparse, etc. array. In one instance, a pitch is selected to ensure a wide steering angle in either 2-D or 3-D and/or a footprint of the array  114  is set to fit a smallest cavity ducted by the user. For example, in one instance the pitch is half a wavelength. The one or more transducer elements  116  are configured to transmit in a range of one (1) to fifty (50) megahertz (MHz). For example, for neurosurgery application, in one instance, the one or more transducer elements  116  are configured to transmit at a frequency that is in a range of five (5) to eighteen (18) MHz. 
     In one instance, the probe  104  is configured for one-dimensional (1-D) imaging. Additionally, or alternatively, the probe  104  is configured for two-dimensional (2-D) imaging Additionally, or alternatively, the probe  104  is configured for three-dimensional (3-D) imaging. Additionally, or alternatively, the probe  104  is configured for four-dimensional (4-D) imaging. In one instance, for 3-D and/or 4-D imaging, the transducer array is swept to acquire volumetric data using mechanical and/or electronical approaches. Mechanical approaches include tilting the transducer via a motor inside the probe and/or otherwise, and electronical approaches include electronically steering the emitted ultrasound beam. 
       FIGS. 14, 15 and 16  schematically illustrate different configurations of the one or more transducer elements  116  for 3-D and/or 4-D imaging. It is to be understood that other configurations are also contemplated herein.  FIG. 14  schematically illustrates a configuration in which the transducer array  114  produces an image plane  1402  that rotates around a long axis  1404  of an elongate end  1406  of the probe  104 . In this embodiment, an axis of rotation  1408  is the long axis  1404 . In the  FIG. 15  schematically illustrate a configuration in which the transducer array  114  rotates an image plane  1502  through a position where the image plane  1502  extends out axially from the long axis  1404  (shown) to other positions, such a where the image plane  1502  is rotated about a short axis  1504  to extend transverse to the long axis  1404 . In this embodiment, an axis of rotation  1506  is the short axis  1504 .  FIG. 16  schematically illustrate a configuration in which the transducer array  114  transmits a 3-D beam  1602  that extends out from the long axis  1404  from a front  1604  of the elongate end  1406 . 
     Returning to  FIG. 1 , as described in greater detail below, in one instance the probe  104  is structurally configured for access into a (natural or artificial) cavity, including reaching a bottom of the cavity for scanning an interior of the cavity, and structurally configured to provide an unobstructed line of sight by the use to a tip of the probe  104  (e.g., the probe head). As such, the probe  104  mitigates having to add saline or other material into the cavity for enabling acoustic coupling between probe and the medium of interest. In one instance, this results in a clear ultrasound image without contamination of brightness/enhancement artifact and without interrupting the user&#39;s workflow. 
     The console  106  includes transmit circuitry (TX)  118  configured to generate the excitation electrical pulses and receive circuitry (RX)  120  configured to process the RF signals, e.g., amplify, digitize, and/or otherwise process the RF signals. The console  106  further includes a switch (SW)  122  configured to switch between the TX  118  and the RX  120  for transmit and receive operations, e.g., by electrically connecting and electrically disconnecting the TX  118  and the RX  120 . 
     The console  106  includes further an echo processor  124  configured to process the signal from the RX  120 . For example, in one instance the echo processor  124  is configured to beamform (e.g., delay-and-sum) the signal to construct a scanplane of scanlines of data. The echo processor  124  can be implemented by a hardware processor such as a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor, etc. 
     The console  106  further includes a display  126 . The output of the echo processor  124  is scan converted to the coordinate system of the display  126  and displayed as images via the display  126 . In one instance, the scan converting includes changing the vertical and/or horizontal scan frequency of signal based on the display  126 . The scan converter can be configured to employ analog scan converting techniques and/or digital scan converting techniques. In a variation, the display  126  is separate from the console  106  and electrically connected thereto. 
     The console  106  further includes a user interface  128 , which includes one or more input devices (e.g., a button, a touch pad, a touch screen, etc.) and one or more output devices (e.g., a display screen, a speaker, etc.). The user interface  128 , in one instance, allows a user to manipulate a displayed image, e.g., zoom, pan, rotate, set/change a gain value, change a display mode, etc. 
     The console  106  further includes a controller  130  configured to control one or more of the probe  104 , the transmit circuitry  118 , the receive circuitry  120 , the switch  122 , the echo processor  124 , the display  126 , the user interface  128 , and/or one or more other components of the imaging system  102 . The controller  130  can be implemented by a hardware processor such as a CPU, a GPU, a microprocessor, etc. 
       FIG. 2  illustrates a non-limiting example of the probe  104 . 
     In this example, the probe  104  includes a probe head  202  with a first end region  204  and a second end region  206 , which spatially opposes the first end region  204 . The transducer array  114  (not visible) is disposed and housed within the probe head  202 . In this example, the probe  104  is configured as an end fire probe, with a transducing side of the transducer array  114  facing out of the first end region  204  of the probe head  202  such that a transmitted beam  205  traverses a direction out of the first end region  204 . 
     The probe  104  further includes a handle  208  with a first end region  210  and a second end region  212 , which spatially opposes the first end region  210 . Electronics  214  for routing electrical signals indicative of received ultrasound pressure fields from the probe  104  to a device remote from the probe  104  are disposed at the second end region  212 . As briefly discussed above, electronics  214  may include a cable and/or a wireless interface. 
     The illustrated handle  208  is cylindrical in shaped and includes a top  216  and a bottom  218  coupled together by sides  220  and  222 . The illustrated handle  208  further includes a least one physical control  224  (e.g., a button) located on the top  216 . In one instance, the control  224  is configured to activate and deactivate transmission and reception. In another embodiment, the control  224  is otherwise located (e.g., on the bottom  218 , etc.) and/or the handle  208  includes another type and/or control(s). For example, in another instance, the handle  208  includes a freeze control button. 
     The probe  104  further includes an elongated shaft  226  with a first end region  228  and a second end region  230 , which spatially opposes the first end region  228 . The second end region  206  of the probe head  202  is coupled to the first end region  228  of the shaft  226 , and the first end region  210  of the handle  208  is coupled to the second end region  228  of the shaft  226 . In this example, the shaft  226  includes a first portion  232  and a second portion  234 . In this example, the first portion  232  is generally linear shaped, and the second portion  234  is non-linear shaped. In this embodiment, a length of the shaft  226  is between three (3) and ten (10) millimeters (mm), such as five (5) mm, six and a half (6.5) mm, etc. 
     In this example, the second portion  234  generally is sigmoid or “S” shaped with a first end region  236  and a second end region  238  and rigid/non-flexible. In other embodiments, the second portion  234  is otherwise shaped (e.g., linear) and/or flexible/non-rigid. The second end region  238  is coupled to the handle  208  between the top  216  and the bottom  218 , which causes the first end region  236  to be raised above the handle  208 , providing a direct line of site  240  to the probe head  202  by a user of the probe  104 , unobstructed from the handle  208 . In one instance, this aids the user with navigating the probe head  202  into a cavity for imaging a surface of an inside of the cavity proximate with the surface without having to add a coupling fluid, such as saline or the like, to the cavity. 
     In one instance, the shape of the shaft  226  mimics that shape of a tool utilized during a resection or other procedure. For example, in one instance the shape of the shaft  226  imitates surgical instruments that surgeons are already using throughout a procedure. That is, the probe  104  has a bend between the probe head  202  that enters the cavity and the handle  208  on which a surgeon operates it. In this example, the bend in part of the second portion  234  and has an angle for the uninterrupted line of sight  240  from the eyes of the operator to the bottom of the cavity. 
     A face  242  of the first end region  204  of the probe head  202  can be variously shaped.  FIGS. 3-8  schematically illustrate several examples.  FIG. 3  depicts a rectangular shaped face  242 .  FIG. 4  depicts a rectangular shaped face  242  with rounded corners.  FIG. 5  depicts a square shaped face  242 .  FIG. 6  depicts a square shaped face  242  with rounded corners.  FIG. 7  depicts an ellipse shaped face  242 .  FIG. 8  depicts a circular shaped face  242 . In one instance, a longest side “A” or diameter of the face  242  is between five (5) and twenty (20) millimeters (mm), such as fourteen (14) mm or other dimension such that it can fit into a burr hole cavity. 
     In  FIG. 2 , a long axis  244  of the handle  208  is at a fixed angle (θ)  246  between zero (0) and ninety (90) degrees with respect to a long axis  248  of the first portion  232  of the shaft  226 . In another instance, as shown in  FIG. 9 , the angle (θ)  246  is fixed at ninety (90) degrees, and the long axis  244  of the handle  208  and the long axis  248  of the shaft  226  are parallel. In another embodiment, the angle (θ)  246  is between that shown in  FIGS. 2 and 9 . In yet another instance, the angle (θ)  246  is fixed at an angle less than that shown in  FIG. 2 , including a negative angle where the second end region  212  of the probe  104  faces the direction of the beam  205 . 
     In another instance, the angle (θ)  246  is adjustable.  FIG. 10  shows an embodiment in which the “S” shaped portion  234  is configured to flex and includes a tension wire  1002 , which is statically connected at a pivot joint  1004 , free at the first end region  238 , and fed through a hollow channel  1006  in the handle  208 . Pulling the tension wire  1002  out of the hollow channel  1006  causes the “S” shaped portion  234  to flex inward/downward, decreasing the angle (θ)  246 . A fastener  1008 , such as a clamp or the like, when engaged, holds the tension wire  1002  at a current position. Disengaging the fastener  1008  allows the tension wire  1002  to move to increase or decrease the angle (θ)  246 . 
     In one instance, the “S” shaped portion  234  is configured to flex between an angle of θ=zero (0) degrees (where the axis  244  is perpendicular to the axis  248 ) and θ=ninety (90) degrees (where the axis  244  is parallel to the axis  248 ). In yet another embodiment, the “S” shaped portion  234  is configured to flex less than ninety (90) degrees. In still another embodiment, the “S” shaped portion  234  is configured to flex more than ninety (90) degrees. For example, in this embodiment the “S” shaped portion  234  flexes such that the angle (θ)  246  is negative and the second end region  212  of the probe  104  flexes and faces the direction of the beam  205 . 
       FIG. 11  shows another embodiment in which the “S” shaped portion  234  is connected to the shaft  226  via a pivot joint  1102  that includes a fastener  1104 , such as a set screw, or the like, that when engaged holds the “S” shaped portion  234  at a current position relative to the shaft  226 . Disengaging the fastener  1104  allows the “S” shaped portion  234  to pivot. Similar to  FIG. 10 , the “S” shaped portion  234  can be configured to pivot less than ninety (90) degrees, ninety (90) degrees or more than ninety (90) degrees, including from where the axes  244  and  248  are parallel to where the second end region  212  of the probe  104  faces the direction of the beam  205 , which is opposite to the direction illustrated in  FIG. 11 . 
       FIG. 12  illustrates another non-limiting example of the system  102 . 
     In this variation, the probe  104  further includes an internal and/or external tracking device(s)  1202  and the console  106  further includes a probe tracking system  1204 , which tracks a spatial orientation of the probe  104  based on a signal from the tracking device(s)  1202 . Suitable tracking devices include electromagnetic, optical, etc. 
     With an electromagnetic tracking device, in one instance tracking coils are included in the handle  208 , the shaft  226 , and/or the head  202 . The tracking system  1204  measures a magnetic field strength of the coils, which depends on a distance and direction of the coils to the tracking system  1204 , and the strength and direction is used to determine location and orientation of the probe  104 . 
     With an optical tracking device, in one instance a fiducial target is placed on the handle  208 , e.g., adjacent the first end region  210  of the handle  208 , which corresponds to a location between the “S” shaped portion  234  of the elongate shaft  226  and a user&#39;s hand on the handle  208 . In one instance, this ensures optimal line of sight between operator and cavity zone and between an optical tracking system and the handle  208 . The tracking system  1204  includes a video camera or the like that records the spatial orientation of the fiducial to determine location and orientation of the probe  104 . 
     Suitable tracking is discussed in Birkfellner et al., “Tracking Devices,” In: Peters T., Cleary K. (eds) Image-Guided Interventions. Springer, Boston, Mass., 2008, and U.S. patent application US 2010/0298712 A1, filed Feb. 10, 2010, and entitled “Ultrasound Systems Incorporating Position Sensors and Associated Method,” which is incorporated herein by reference in its entirety. Other approaches are also contemplated herein. 
       FIG. 13  illustrates an example method in accordance with an embodiment herein. 
     It is to be appreciated that the order of the below acts is not limiting, and in other embodiments, there may be more, less and/or different acts. 
     At  1302 , the ultrasound imaging probe  104  is procured. 
     At  1304 , a portion of an object within the object is removed, creating a cavity. 
     At  1306 , the head  202  of the ultrasound imaging probe  104  is positioned in the cavity. 
     At  1308 , the ultrasound imaging probe  104  is activated to image an inside of the cavity. 
     The application has been described with reference to various embodiments. Modifications and alterations will occur to others upon reading the application. It is intended that the invention be construed as including all such modifications and alterations, including insofar as they come within the scope of the appended claims and the equivalents thereof.