The present invention is directed to system, apparatus and method for holding and positioning a medical imaging instrument. More particularly, the invention relates to an apparatus adapted to hold a medical imaging instrument such that the instrument may be positioned, secured and/or rotated about at least one fixed axis by a positioning device.
Doctors and other medical professionals often utilize medical imaging instruments to conduct non-invasive examinations. That is, medical imaging instruments, including X-ray, magnetic resonance (MR), computed tomography (CT), ultrasound, and various combinations of these instruments/techniques are utilized to provide images of internal patient structure for diagnostic purposes as well as for interventional procedures. These medical imaging instruments allow examination of internal tissue that is not readily examined during normal visual or tactile examination. Applications include imaging in the areas of urology, brachytherapy, cyrotherapy, photo-dynamic therapy, or a combination of these therapies and/or fusion-guided biopsies.
Medical imaging devices typically allow for generating three-dimensional (“3-D”) images of internal structures of interest. Such 3-D imaging may improve the accuracy and/or reliability of medical diagnosis. For instance, a medical imaging device may be utilized to generate a 3-D model or map of the prostate such that one or more biopsies may be taken from a desired location of the prostate. For purposes of prostrate imaging, a transrectal ultrasound-imaging device (e.g., a “TRUS probe” or “ultrasound probe”) may provide image acquisition and guidance. The ultrasound probe is a widely accepted technique for prostate applications due to its simplicity, high specificity, and real time nature. In such an application, the ultrasound probe or any other medical imaging device may be inserted into the rectum of a patient to generate an image. Such images may be utilized to take one or more biopsies from a prostate location of interest and/or implant radioactive seeds at one or more desired locations in a brachytherapy procedure.
In order to generate 3-D images, many medical imaging devices obtain a plurality of two-dimensional (“2-D”) images and combine these images together to form a 3-D image. Accordingly, movement of a medical imaging device between the acquisition of individual images makes it more difficult to properly align (e.g., register) the different images for purposes of generating accurate 3-D images. Thus, precise and repeatable placement and guidance of the medical imaging device is desirable to achieve accurate imaging and rendering of the applicable therapy.
Traditionally, a medical practitioner manipulates a medical imaging device by hand for medical image acquisition and/or treatment. That is, the medical practitioner manually guides the instrument. Such manual manipulation is suitable for many medical procedures. However, in instances where it is desirable to obtain multiple images for 3-D image generation, manual manipulation of the device may result in movement between images. Further, for biopsy and other treatment procedures it is desirable to know the relative location between an imaging instrument and a tissue area of interest. That is, it is important that the device directs an imaging field to a particular tissue location and remain stationary to allow for guiding a biopsy/treatment device to a tissue location within the imaging field. Relative movement between the imaging device and the tissue area of interest during imaging and/or biopsy/treatment may impede the successful performance of these procedures.
Accordingly, a number of probe holding and manipulating/positioning assemblies have been proposed. These assemblies generally involve a holder that interfaces with a medical imaging device such as an ultrasound probe. The holder is then interconnected to one or more mechanical armatures and/or actuators such that the probe may be mechanically positioned and/or rotated relative to an area of interest on a patient (a “positioning device”). While this approach is generally effective, a number original equipment manufactures (“OEMs”) produce handheld probes in the market (e.g., Asucon, Aloka, ATL, B&K, Diasonics, General Electric, Hewlett Packard, Hitachi, Interspec, Philips, Siemens, Toshiba, etc.). While these probes do have some commonalities, they do not have a standardized design. Each probe generally has an acquisition or insertion portion and a handle portion. Typically, the acquisition portion is offset at an angle from the handle portion for ergonomic purposes. That said, probes produced by different manufactures feature acquisition portions and handle portions of differing lengths, widths, configurations, and offsets. Because limiting the rotation of the probe about an axis defined by the acquisition portion of the probe (an “acquisition axis”) removes a degree of freedom from subsequent calculations used to register a sequence of 2-D images together to form a 3-D image, the lack of conformity between probes has resulted in the need for specialized positioning devices for differently configured ultrasound probes. Accordingly, prior positioning devices have required that a medical facility utilize a particular probe with a particular specialized positioning device.
The present invention provides systems and methods for interfacing variously configured medical imaging devices for imaging applications (e.g., TRUS probes or other ultrasound probes, biopsy needles, therapeutic devices, medical imaging devices, etc.) in a fixed positional relationship with a positioning device. Such positioning devices may be utilized to position medical imaging devices relative to a patient tissue of interest. Aspects of the present invention provide an apparatus for interfacing an ultrasound probe with such a positioning device.
The apparatus embodied by a first aspect includes a connector and a probe holder. The connector is adapted to be rotatively coupled to a positioning device such that the connector is operative to rotate relative to the positioning device about a rotational axis. The probe holder includes a recessed surface that is sized to receive and secure at least a portion of an ultrasound probe. In addition, the probe holder is coupled to the connector at a location that is spaced from the rotational axis, and as a result, the recessed surface is offset from the rotational axis. This offset may allow an acquisition portion of a probe placed in the recessed surface to be aligned with the rotational axis of the positioning device.
The connector may be coupled to both the positioning device and the probe holder in any appropriate manner that allows the connector, and thus the probe holder, to rotate about the rotational axis. For instance, the connector may be fixedly coupled to a mating shaft that is rotatively coupled to the positioning device so as to allow the positioning device to rotate the connector via the mating shaft. In addition, because the probe holder is coupled to the connector at a position that is spaced from the rotational axis, the probe holder may orbit the rotational axis when the positioning device is in operation.
In one arrangement, the apparatus may include an ultrasound probe disposed within the recessed surface of the probe holder. The ultrasound probe may have a handle portion that generally defines a handle axis and an acquisition portion that generally defines an acquisition axis. In some cases, the handle axis and the acquisition axis may be nonconcentric. However, when the handle portion is disposed and/or secured within the recessed surface, the rotational axis of the positioning device and the acquisition axis of the acquisition portion of the probe are substantially concentric. This concentric alignment allows the acquisition portion of the probe to rotate about the rotational axis substantially free of precession or wobble, which may provide for improved image registration.
In one arrangement, the recessed surface of the probe holder may be correspondingly shaped to the handle portion of the probe. When the recessed surface of a particular probe holder is correspondingly shaped to concentrically align a particular probe, different probes having different configurations may utilize different probe holders to interface with the positioning device. That is, each different probe may utilize a customized probe holder.
In another arrangement, the apparatus may include a flexible joint disposed between the connector and the probe holder. The flexible joint may permit the selective adjustment and/or alignment of the probe holder, and thus a secured probe, in relation to the rotational axis of the positioning device. That is, the flexible joint may allow for aligning an acquisition axis of the probe with the rotational axis of the positioning device. As a result, the flexible joint may allow for more general use of the probe holder, or allow for a single probe holder to be used with various probe configurations.
The flexible joint may include one or more rotational, revolving, gyratory, or other joints of any appropriate size, type, and/or configuration. For instance, the flexible joint may include one or more ball-and-socket joints, a ball-bar-socket joint, a binge joint, or any other appropriate joint that allows for adjustment within multiple degrees of freedom.
The apparatus may also include a locking mechanism adapted to lock the flexible joint in a desired position. For example, in one arrangement, one or more securement plates may be tightened about each ball-and-socket or other rotational joint so as to prevent further movement of the rotational joint. The securement plates may be tightened with threaded fasteners such as, for example, set screws, thumbscrews, cap screws, etc.
In another aspect of the present invention, an alignment fixture may be used to adjust a flexible joint of a probe holding apparatus to concentrically align a rotational axis of a positioning device with an acquisition axis of an ultrasound probe. In this aspect, the alignment fixture may include a base that supports a probe holding apparatus in a desired relationship to the rotational axis. In one arrangement, a connector of the apparatus may be fixedly positioned relative to the rotational axis, and a probe holder of the apparatus may then be adjusted. In such an arrangement, a probe holder may be coupled to the connecter via a flexible joint. The alignment fixture may also incorporate an indicator that provides an indication of the alignment of the acquisition axis of a probe disposed in the probe holder to the relational axis. For example, when an ultrasound probe is secured within the probe holder, a lever arm of such an indicator may engage the acquisition portion of the probe such that when the mating shaft rotates the probe, the indicator detects any precession in the acquisition portion of the probe. If precession is detected, the flexible joint may be adjusted until the acquisition portion of the probe rotates about the rotational axis substantially free of precession before the flexible joint is secured
Reference will now be made to the accompanying drawings, which assist in illustrating the various pertinent features of the present disclosure. Although the present disclosure is described primarily in conjunction with transrectal ultrasound imaging for prostate imaging, it should be expressly understood that aspects of the present invention may be applicable to other medical imaging applications. In this regard, the following description is presented for purposes of illustration and description.
Systems and methods are disclosed that facilitate obtaining medical images and/or performing medical procedures. One embodiment provides a medical imaging device holder (i.e., probe holder or holder) that has a recessed surface adapted to securely support a particular ultrasound probe for interfacing the ultrasound probe in a fixed positional relationship with a positioning device. Another embodiment provides a probe holder that allows for more general use of a single holder assembly that is capable of securely supporting a variety of different ultrasound probes in a desired positional relationship with a positioning device. The probe holders of the present invention may be interfaced with a positioning device such that the acquisition axis of the supported probe may be rotated about the rotational axis of the positioning device in a manner substantially free of precession or wobble. In this regard, the supported probe may obtain multiple images in different angular positions for 3-D image generation. Because the positioning device securely supports the probe, there may be little or no probe movement between successive images, other than rotation about the rotational axis. Accordingly, successive images may more easily be registered together.
As shown in
Accordingly, it is desirable to minimize relative movement between the probe 10 and the prostrate 12 (i.e., precession, wobble or any other rotational movement of the probe about a fixed axis for image acquisition). It is also often desirable for probe 10 to remain fixed relative to the prostrate 12 during biopsy or other treatment procedures such that the desired tissue locations may be targeted accurately. To achieve such fixed positioning of probe 10, it is often desirable to interface the probe 10 with a positioning device such as the exemplary positioning device 100 shown in
The present invention may be used to interface an ultrasound probe with various positioning devices of the type discussed above. One exemplary positioning device is set forth in International Application Number PCT/CA2007/001076, entitled Apparatus for Guiding a Medical Tool. Another is set forth in U.S. application Ser. No. 11/850,482, entitled Tracker Holder Assembly, the contents of which are fully incorporated herein by reference.
In order to utilize the probe 10 with the positioning device 100 as illustrated in
As discussed above, the dimensions (e.g., lengths and/or diameters) of any or all of these components 14, 16 and 18 may vary between probes of different manufactures. Further, these components may be tapered and/or set at an angle to one another. Therefore, to interface different probes 10 to a common positioning device 100 typically requires individual probe interfaces.
Accordingly,
In this embodiment, the holder assembly 50 includes a probe holder 52 and one or more operably connected straps 54 for cinching or securing the handle portion 16 of the ultrasound probe 10 within the probe holder 52, as shown in
In the embodiment of
A mating shaft 102 of the positioning device 100 (
In this embodiment, the holder assembly 150 incorporates a flexible joint 158, which allows for more general use of the probe holder 152. Specifically, the holder assembly 150 includes a probe holder 152 having a recessed surface that can accommodate a variety of different ultrasound probes 10. One or more straps 154 or clamps are operably connected with the probe holder 152 such that the selected probe 10 may be cinched or otherwise secured within the probe holder 152, as shown in
Because the probe holder 152 does not have a custom recessed surface for each particular ultrasound probe 10 (i.e., the recessed surface is not configured for each particular ultrasound probe), the holder assembly 150 includes the flexible joint 158 between the probe holder 152 and the connector 156. The flexible joint 158 allows the recessed surface (which engages the probe handle) of the probe holder 152 to be adjusted to bring the acquisition axis AA′ (
A second ball 161 mates with a socket (not shown) formed within an offset portion 168 of the connector 156. When disposed within the sockets, the first and second balls 160, 161 may be adjusted through nearly unlimited degrees of freedom in order to concentrically align the acquisition axis AA′ (
To secure the balls 160, 161 in their respective aligned positions within the sockets, two securement plates 164 (
While the flexible joint 158 has been described as having two ball-and-socket joints, it should be understood that the flexible joint 158 may include additional or fewer rotative or other joints of any appropriate size, type, and/or configuration.
In some instances, an alignment fixture may be used to adjust the flexible joint 158 as discussed above.
The alignment fixture 200 includes a base having a first bar 210 that fixably connects a first end 112 and a second end 214. The first end 212 includes a mating shaft holder 203 that fixably couples to a second bar 216 through a disk 218. The mating shaft holder 203 also receives the mating shaft 102 of the positioning device 100 (
The acquisition portion of the secured probe 10 extends through two apertures 216 formed by corresponding biasing collar assemblies 206 that are coupled to a distal end of the second bar 216. The biasing collar assemblies 206 allow for the selective and incremental positioning of the acquisition portion 14 of the supported probe 10. As shown in further detail in
In addition, biasing members (not shown) are disposed within the aperture 226 and opposite the adjustment screws 222. The biasing members deflect slightly to accommodate the acquisition portion 14 of the supported probe 210. This slight deflection causes the biasing members apply a compressive force between the acquisition portion 14 and the adjustment screws 220. As a result, the biasing members deflect further when the acquisition portion 14 shifts in response to incremental movement of the adjustment screws 218, thereby allowing the axis AA′ of the acquisition portion 14 of the probe 10 to be concentrically aligned with the rotational axis CC′ of the mating shaft. It should be appreciated that the biasing members may be coil springs, leaf springs, or any other bias springs of appropriate size, type, and/or configuration.
To gauge probe alignment, the alignment fixture 200 may also include a dial indicator 230 having a lever arm (not shown) that engages the acquisition portion 14 of the supported probe 10. As the mating shaft 102 rotates the supported probe 10, the indicator 230 detects any precession or wobble in the acquisition portion 14 of the probe 10. If precession is detected, the biasing collar assemblies 206 may be adjusted to bring the acquisition portion 14 of the probe 10 into concentric alignment with the shaft 102, as discussed above. Once aligned, the securement plates 164, 165 of the flexible joint may be tightened about the ball-and-socket joints to secure the probe 10 within the holder assembly 150 in an aligned position.
It will be appreciated that though a finite number of exemplary embodiments have been discussed herein, the various elements of those embodiments may be used separately or combined together. For example, the customized probe holder 52 may be used in conjunction with the holder assembly 150 having the flexible joint 158.
The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described above are further intended to explain best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in similar or other embodiments and with various modifications required by the particular application(s) or use(s) of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.
This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 60/986,866 entitled “Axis Alignment Method” and having a filing date of Nov. 9, 2007, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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60986866 | Nov 2007 | US |