Abstract:
An apparatus for supporting and facilitating accurate positioning, both linearly and angularly of a medical device such as an ultrasound probe, a medical instrument or an imaging device. The apparatus is capable of both gross and precise multi-directional movements with the medical device attached, while remaining connected to stationary objects such as a portable floor stand and/or operating table. After gross manual placement and approximate positioning, the fine tune mechanism of the attached medical device is locked in positioned and secured to two fixed points. Exact positioning is then achieved by the precision movements which are available in all three linear directions and rotational axes. By this arrangement which allows preattachment of the medical device or instrument (i.e., an ultrasound probe) to the apparatus prior to positioning in the patient, quicker, more accurate and more reproducible medical device positioning and placement are achieved. In one preferred embodiment, the apparatus provides for multi-directional adjustment including a plurality of translational adjustments and one rotational adjustment.

Description:
This application is the United States National Phase Application of PCT Application No. PCT/US98/01252, filed Jan. 21, 1998, which claims the benefit of U.S. Provisional Application No. 60/069,225, filed Dec. 11, 1997 and is a continuation of U.S. application Ser. No. 08/955,321, filed Oct. 21, 1997 and now U.S. Pat. No. 5,961,527, which in turn was a continuation-in-part of U.S. application Ser. No. 08/787,155, filed Jan. 22, 1997, now abandoned. 
    
    
     TECHNICAL FIELD 
     This invention relates generally to a support apparatus for precision medical instruments, and more particularly to an adjustable support apparatus and system for ultrasound imaging probes and other instruments for use in surgery. 
     BACKGROUND ART 
     As advances are made in the medical field, surgical procedures requiring precise positioning of monitoring and surgical tools become necessary. For example, radiologists perform numerous percutaneous guided biopsies using ultrasound and computer aided tomography (“CAT”) scanning techniques, magnetic resonance imaging techniques and fluoroscopic imaging techniques. Biopsies and other percutaneous procedures are performed using a variety of needle-like instruments. It would be advantageous to stabilize such instruments or at least be able to manipulate them in a more precise manner than with manual operation. 
     For example, one currently widely applied and popular method for the treatment of prostate cancer is the percutaneous transperineal implantation of radioactive seeds of either Iodine-125 or Palladium-103. This procedure is performed with the patient in the lithotomy position, using an ultrasound imaging probe placed in the rectum to monitor seed placement. A template arrangement which is kept in precise linear orientation with the ultrasound probe must be accurately oriented adjacent to the perineum in relation to the prostate, and locked in position throughout the procedure to achieve optimum seed placement. Precise and reproducible orientation of the ultrasound imaging probe in the rectum is the key element in both the calculations required for determining the number and distribution of radioactive seeds required for treatment and their subsequent placement using pre-loaded needles guided by the perineal template and real time ultrasound imaging. This form of treatment for prostate cancer has been increasing in popularity because of minimal patient morbidity compared to other available treatments and the potential for improved efficacy due to increasingly accurate methods of seed placement. 
     Presently, there are many homemade and commercially available devices for holding, manipulating and stabilizing the various commercially available ultrasound imaging probes designed for use in this procedure. None of these devices have achieved wide acclaim because of significant limitations in their ease of use. In general, these devices suffer from the same basic limitation in that they are “post-insertion” probe fixation devices where the probe is first inserted into the rectum and then affixed to a stand. This inevitably leads to a reorientation of the probe, vis-à-vis the insertion cavity, and valuable time is wasted in recreating mechanically the desired probe orientation that was readily achieved with the freedom of omni-directional manual movement. 
     In an attempt to remedy these shortcomings, certain “pre-insertion” fixation devices have been developed. In these devices, the probe is first affixed to a stand and then the combination of the fine adjustment mechanism with the probe affixed is released to the free “omni-directional” mode to enhance insertion of the probe into the body of the patient. For prostate cancer treatment, for example, the probe is manually inserted into the rectum and, once the desired orientation is achieved as viewed and confirmed by the monitored ultrasound images, the device is then “set” in the “fixed” mode. 
     Many currently available devices provide multi-axis movement, but movement in one or more of these axes is clumsy, inaccurate and risks significant loss of orientation in other axes during adjustment, or control of the fine adjustment is severely limited. Moreover, such current devices are cumbersome and tend to either be heavy and/or broad-based to achieve floor stand based stability or spatially cumbersome table-mounted structures which tend to obstruct the surgeon&#39;s movements and patient access. 
     Several presently available examples of post-insertion cumbersome devices for prostate treatment are available in the marketplace. One such device is available from Seed Plan Pro of Seattle, Wash. called the Northwest Transperineal Prostate Implant Stabilization Device. Another such currently marketed device very similar thereto is offered by Hutchinson Medical Designs. A third similar immobilization device offered by Mick Radio-Nuclear Instruments, Inc. of Bronx, N.Y. is called the Cotan Stabilizing Device. Mick also distributes the Martin Immobilization Device which can be used as a “pre-insertion” fixation device but has no fine adjustment mechanism for positioning after insertion. Thus, there remains a need for improved holding, manipulation and stabilizing devices for use in this procedure. In addition, there are numerous other medical procedures where enhanced holding, manipulation and/or stabilizing devices can be helpful. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the above prior art shortcomings and includes the following features: 
     1. A universal mounting platform on which a variety of commercially available imaging probes, needles or similar instruments may be attached prior to insertion of the instrument into the body of the patient; 
     2. Six axis, fine adjustment for the mounting platform, which provides positive control of probe movement in the X, Y and Z directions and rotation about the X, Y and Z axes for optimum probe orientation and allows for any probe or instrument to be properly “zeroed” at the desired location for accurate measurement, seeding biopsy or other treatment; 
     3. A set of lockable two-segment articulating arms having end universal joints allowing for low resistance, free-hand, manual instrument placement while the instrument remains fully engaged to the platform apparatus and floor and/or operating table whereupon the ideal manual placement may be quickly fixed in place and secured to two fixed points; 
     4. A universal stabilizing arm which adapts to any table without modification and, in combination with the portable floor stand, provides a multi-functional unit which can be used with or without the floor stand or, after initial placement, transferred from the floor stand to full table mounting support without loss of position; 
     5. A light, freely mobile, wheeled, stable floor stand with adjustable feet and one-step lockdown mechanism; and 
     6. An offset base of the stand to provide wide-base stability while allowing the operator to stand close thereto without interference. 
     The present invention has applicability to other surgical procedures which require steady, but mobile instrumentation such as cryosurgery, thermotherapy and laser surgery and any procedure where precision movement of imaging or operating instrumentation is required. In addition to the application with prostate cancer seed implantation described above, this omni-directional precision instrument platform apparatus can be used in minimally invasive surgery for prostate cancer and BPH, including laser ablation of benign prostatic hyperplasia, transurethral needle oblation of the prostate, microwave therapy for both BPH and prostatic carcinoma, and cryosurgery for prostatic carcinoma. Furthermore, this apparatus is useful in percutaneous surgical biopsies. Radiologists typically perform such procedures utilizing any one of a wide variety of radiological instruments or probes to assist in locating or contacting the organ or tissue to be biopsied. CAT scanning and ultrasound x-ray, fluoroscopic or MRI imaging can be used to perform precision biopsies with the present apparatus. In all these minimally invasive procedures, and in other fields of surgery as well, there is great need and potential for an instrument fixation device which is as versatile and precise as that which is disclosed and claimed herein. 
     This invention is specifically directed to an apparatus and system for supporting and facilitating accurate manual positioning, both linearly and angularly, of an ultrasound probe, needle biopsy guide or other instruments used during surgical or diagnostic procedures and, thereafter for securing that positioning with respect to, and while remaining connected to, a stationary object such as a portable floor stand included in the system and/or an edge of a table and the like. After freehand manual positioning of the imaging device or instrument which has been previously fixed to the fine adjustment mechanism, the combination is “set” and further finely controlled movements and angular reorientation in all three linear directions and rotational axes, respectively, (i.e., omni-directional) may be made by adjusting mechanisms of the apparatus provided. By this arrangement, quicker, more accurate and/or reproducible imaging or instrumentation is achieved. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation view of a preferred embodiment of the apparatus  10  with one rotational adjustment knob  68  and associated mechanism removed for clarity. 
     FIG. 2 is a top plan broken view of FIG.  1 . 
     FIG. 3 is a perspective view of the apparatus of FIG.  1  and including a stepping device  80  for receiving a transrectal ultrasound imaging probe (not shown) and upper portions of lockable articulating arms  120  and  120   a  of the system. 
     FIG. 4 is a front end elevation view of FIG.  3 . 
     FIG. 5 is a right side elevation view of FIG.  3 . 
     FIG. 6 is a top plan view of FIG.  3 . 
     FIG. 7 is a perspective view of a portable floor stand and a lower end of the lockable articulating arm  120  of the system. 
     FIG. 8 is a side perspective view of the system  150  which includes the apparatus  10  shown in FIG. 3 supported on the portable floor stand  100  of FIG.  7  and articulating lockable arms  120  and  120   a.    
     FIG. 9 is a side schematic view of the preferred embodiment of the system  150   a  in use. 
     FIG. 10 is a perspective view of another preferred embodiment of another positioning apparatus according to the invention. 
     FIG. 11 is a perspective view of yet another preferred embodiment of a positioning apparatus according to the present invention. 
     FIG. 12 is an exploded view of the components of the embodiment of FIG.  11 . 
     FIG. 13 is another view of the embodiment of FIG. 11 with one arm detached. 
     FIG. 14 is an enlarged view in part of the apparatus of FIG.  11 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and particularly to FIGS. 1 and 2, the preferred embodiment of the omni-directional position and orientation adjusting apparatus of the invention is shown generally at numeral  10  for use in placement of seedings for treating prostate cancer. 
     The apparatus  10  includes first, second, third and fourth descendingly spaced and somewhat coextensive plate members  12 ,  14 ,  36 , and  54 . The first or upper plate member  12  is structured as best seen in FIG. 3 for supportive connection with a stepping device  80  (not shown in FIGS. 1 and 2) which is commercially available for receiving a transrectal ultrasound imaging probe and other similar precision medical instrumentation. Generally positioned between the second or intermediate plate  14  and the upper plate  12  is an arrangement which effects rotational positioning about a longitudinal and a transverse axis therebetween. The upper and second plates  12  and  14 , respectively, are pivotally connected one to another by universal cross members  16  and  18  which are themselves connected together centrally and connected at each end thereof into support blocks  20  and  22 , respectively, blocks  20  being connected atop second plate  14  while blocks  22  are connected to the lower surface of upper plate  12 . By this arrangement, upper plate  12  is rotatable about the orthogonal longitudinal and transverse axes of cross members  18  and  16  in the direction of arrows A 1  in FIG.  1  and A 2  in FIG. 4, respectively. 
     Two upright compression springs  24  oriented at 90° to one another about upright axis G with respect to the axes of cross members  16  and  18  are positioned between aligned end portions of plates  12  and  14 . A guide pin  26  connected to second plate  14  within each spring  24  maintains the stable configuration of each spring  24  under compression. Two adjusting members  30  which are threadably engaged onto threaded shafts  28  mounted and upwardly extending from the opposite ends of second plate  14  from springs  24 . A spherical ball  32  positioned between upper plate  12  and the upper end of each adjusting member  30  provides for minimal frictional contact at that point so that, as adjusting members  30  are each rotated about their respective threaded shafts  28 , movement in the direction of arrows C and D effects the angular orientation A 1  and A 2 . Instead of the spherical ball, a conical or triangular shaped point can be used to achieve low friction contact with the plate. 
     A plastic spacer block  34  is positioned between second plate  14  and third plate  36 , spacer block  34  being slideably positioned therebetween. Two fully threaded shafts  40  and  46  are threadably engaged in orthogonal fashion through block  34 . Threaded shaft  40  slideably engages through end support blocks  38  which are connected near each longitudinal end of second plate  14 , while threaded shaft  46  is slideably engaged through end support blocks  42  connected adjacent each lateral end of third plate  36 . Adjusting knob  44  at one end of the threaded shaft  40  is provided to effect linear movement of second plate  14  in the direction of arrow B with respect to block  34  and third plate  36 . Adjusting knobs  48  at each end of threaded shaft  46  facilitate lateral movement in the direction of arrow H of second plate  14  with respect to block  34  and third plate  36 . 
     Angular orientation about the upright longitudinal axis G of this apparatus  10  is effected by rotation of adjusting knob  68  and threaded shaft  58  (not shown in FIG.  1 ). Threaded shaft  58  is threadably engaged into plastic block  60  which, in turn, is held for pivotal movement only about pin  62 , the lower end of pin  62  being connected to one end  54   a  of fourth or lower plate  54 . Frictional tensioning and positioning of knob  68  against bracket  56  connected to third plate  36  is accomplished by threaded nut  66  against spring  64 . By suitable rotation of adjusting knob  68 , movement of flange  56  in the direction of arrow F effects rotational movement of third plate  36  and, consequently second plate  14  and upper plate  12 , about the vertical axis G. 
     Referring now to FIGS. 3,  4  and  5 , the apparatus  10  also includes a support tube  50  which slideably engages within an outer support tube  52  connected and downwardly extending from lower plate  54 . By this arrangement, in combination with the structure and function associated with adjusting knob  86  previously described, only vertical movement in the direction of arrow E between third plate  36  and lower plate  54  is provided. To achieve fine vertical adjustment in the direction of arrow E, a threaded shaft  85  seen in FIG. 5 which is connected to, and extends downwardly from support tube  50 , threadably engages into plastic adjusting wheel  86 . The plastic adjusting wheel  86  is held for rotational movement only with respect to outer support tube  52  by block  84 . The vertical movement adjusting wheel  86  and associated cooperating members at the lower end of outer tube  52  of FIG. 1 is best seen in FIG.  3 . 
     Referring now to FIGS. 6 to  8 , the entire system of the present invention is shown generally at numeral  150  and includes the apparatus  10  previously described, articulating lockable arms  120  and  120   a  and a portable floor stand  100 . The floor stand  100  seen best in FIG. 7 is structure to facilitate both easy rolling during transport and quick stationary lockability during use. A rolling frame  104  includes an upright rectangular tubular member  102  and radially extending legs having rolling wheels downwardly disposed at each end. A lockdown frame  108  also includes an upwardly extending rectangular tubular member  106  which slideably engages within tubular member  102 . Disposed at the lower end of tubular member  106  is a stabilizing base which includes radially extending arms and non-skid floor contact members. An eccentric adjusting cam  110  is pivotally connected to tubular member  106  such that the periphery of the adjusting member  110  contacts one upper margin of tubular member  102 . By rotation of the adjusting member  110 , the lockdown member  108  is either placed in contact with the floor or elevated to place the wheels in contact with the floor. By this arrangement, once the entire system  150  is generally positioned as desired, the floor stand  100  may be quickly locked in place to secure that overall positioning. 
     In this system embodiment  150 , two articulating lockable arm members  120  and  120   a  are provided. Each of these arm members  120  and  120   a  include two separate arm segments  90 / 116  and  88 / 117 , respectively which are each pivotally connected one to another at locking knobs  118  and  98 , respectively. Each of the ends  92 ,  94 ,  114  and  122  of these articulating arm members  120  and  120   a  include universally movable support shafts  62 ,  73 ,  112  and  119 , respectively. The lockable articulating arms  120  and  120   a  are thus angularly orientable at three locations when locking handles  98  and  118  are released and simultaneously lockable after being selectively positioned. These lockable articulating arms  120  and  120   a  are commercially available and are called Three-Link locking lever mechanisms. Such devices are included in the prior art Martin Immobilization Device described in the background. 
     Connected to shaft  119  is a table clamp  124  which is quickly engagable onto an edge of a table T by locking handle  126 . While shaft  112  of articulating arm  120  is shown threadably engaged into the upper end of floor stand  100 , a similar self-locking member  124  may be substituted therefor as will be described in FIG.  9 . 
     By this arrangement, after floor stand  100  has been generally positioned with respect to a patient or an operating table and locked in that position as previously described, a precision medical instrument such as an ultrasound imaging probe which has been mounted in stepping member  80  may be manually positioned while articulating arm members  120  and  120   a  are in the unlocked position. Thereafter, by simply rotating locking knobs  98  and  118 , the manually selected position and orientation of the precision instrument is fully maintained. 
     Referring to FIG. 9, a schematic of the preferred embodiment of the invention in use for radioactive seed implantation in a diseased prostate P of a patient is shown at numeral  150   a.  The omni-directional adjusting apparatus  10  has the stepping member  80  mounted thereatop. Mounted within the stepping member  80  is the transrectal ultrasound imaging probe  130  which is initially positioned manually for having probe  132  inserted into the rectal area of the patient. During the surgical procedure, one articulating arm  120   a  is connected to table T′ while the other articulating arm  120   a  is connected to an upper support member  113  of floor stand  100   a.  Floor stand  100   a  is otherwise identical to the floor stand  100  previously shown and described in FIG.  7 . 
     In one embodiment of method of use, to initially manually position the ultrasound probe  130 , the locking knobs  118  of each articulating arm  120   a  are released. A surgeon or medical practitioner may than manually manipulate the ultrasound probe  130  by grasping shaft  52  or as may be otherwise convenient. By monitoring the image output of the ultrasound probe  130  with a conventional CRT monitor or the like, the surgeon may carefully place the probe  132  into the rectal area for optimal initial alignment. While still holding this initial alignment, locking knobs  118  of each of the articulating arm assemblies  120   a  are then quickly locked to secure the manually selected initial alignment and orientation of the probe  132 . Should floor stand  100   a  be inconveniently positioned, lock member  124  may be released to remove floor stand  100   a  and then reconnected to another fixed or stationary object such as an edge of table T. 
     In a preferred method of use, only a single articulating arm assembly  120   a  which is connected to floor stand  100   a  or table, is used as above described to establish the manually selected initial placement of the ultrasound probe  130 . Thereafter, the other articulating arm  120   a  is connected between lower plate  54  and another stationary or fixed in place object such as the edge of table T′. This preferred sequence of use minimizes obstacles that might be in the way of the surgeon performing the initial instrument placement during the procedure. 
     After the ultrasound image probe  130  is thus positioned and secured in the manually selected initial orientation by either of the above methods, each of the omni-directional fine adjusting mechanisms of the apparatus  10  as best shown in FIGS. 1 and 2 and as previously described may be carefully adjusted to fine tune the positioning of the probe  132 . Note that each of the six adjustments for linear positioning in all three orthogonal directions and rotational orientation about all three orthogonal axes are accomplished individually and without affecting any of the other adjusted positions. 
     A preferred use of the system  150   a  is depicted in FIG. 9 in conjunction with the implantation of radioactive seeds into a diseased prostate P. This procedure is also depicted in conjunction with promotional brochures for the Martin Immobilization Device. A template  134  is connected to the stepping device  80  and generally orthogonally oriented with respect to the longitudinal axis of the ultrasound transducer  130 . The transparent template  134  includes a plurality of evenly spaced small holes  140  formed therethrough to receive an implant needle  138  of a seed implant device  136 . Assisted. by CRT images provided by the ultrasound probe assembly  130 , exact positioning of implant needle  138  and the radioactive seeds within the prostate P is achieved. 
     In general, the invention thus provides an instrument platform for facilitating omni-directional freehand positioning of the instrument during perineal surgery, for immediate securement of the chosen freehanded instrument positioning to at least one and preferably two fixed objects and, finally, for fine omni-directional micro-adjustment of the instrument position and angular orientation about all three linear axes and about all three axes of rotation of the platform. Perineal surgery includes surgery of the rectal, vaginal, urethral and perineal areas. 
     FIG. 9 shows another embodiment of the apparatus  160  of the invention. This device is essentially the same as that shown in the previous drawings, with the exception that stepping device  80  is not present. Where the same components are present as in the other figures, the same numerals have been used. 
     In place of stepper so, the apparatus of FIG. 9 includes a simple support plate  165  which can be secured to plate member  12  by screws and bolts or the like. Upon this support plate  165  can be mounted any one of a wide variety of probes, biopsy guides, needles, needle guides, or other instruments for use in surgical or diagnostic procedures. One of ordinary skill in the art can easily provide the necessary adapters, supports or grips for these instruments so that they can be securely mounted to support plate  165 . The apparatus  160  can then be used to enhance the accuracy and security of the procedure. For example, for percutaneous biopsy, it is easy to image the biopsy line with all necessary equipment lined up in position. This provides a positive confirmation of accuracy before and during the actual biopsy by standard imaging techniques and avoids the uncertainties and variables associated with manual manipulation. 
     For certain procedures, fine adjustment in only three rather than four planes provides sufficient precision. Four planes would be used for the most critical procedures for best results. Thus, the present device is useful for guided biopsy of the breasts, thyroid or kidney as well as for other intra-abdominal or retroperitoneal organs or areas. This device is designed to hold needle biopsy guides in a precise way to allow intermittent imaging and use of a variety of modalities to confirm position before advancing the needle to biopsy the tissue of concern. 
     Referring to FIG. 11, another embodiment of a positioning apparatus  210  according to the present invention includes a side to side adjustment knob  212  which provides for translational movement along an X axis. A vertical adjust knob  214  provides for translational movement along AY axis. A plastic threaded knob  216  can be tightened to limit the vertical adjustment and the unit&#39;s travel. The plastic knob  216  cooperates with a milled flat  217  as shown in FIG. 12 for guiding the vertical limits of adjustment. The plastic threaded knob  216  sits on the milled flat  217  to lock the vertical adjustment and eliminate tolerance in the system or apparatus. Another knob  218  provides for front to back adjustment along AZ axis of translational movement. 
     In addition to the three translational adjustments along the above-identified X, Y and Z axes, the apparatus  210  also provides for one rotational adjustment along a predetermined axis. This rotational adjustment is obtained by knob  220  which allows for a tilt control of about plus or minus 7 degrees about a rotational Z axis. The rotational adjustment obtained by knob  220  works against the compression of spring  222  as shown on the opposite side in FIG.  11 . The spring  222  holds the top plate in position. 
     The apparatus  210  also includes a handle  224  as well as universal jointed arms  226  and  228  which have clamps  230  and  232 , respectively. If desired, arm  226  can be detached so that the remaining arm  228  can be used to connect the apparatus  210  to a table. The apparatus  210  does not require a wheeled base. 
     As shown in FIG. 12, the components of the apparatus  210  include lead screws  234  and  236  which have knobs  212  and  218  on one end thereof. A plastic block  238  has threaded passages  240  for the lead screws  234  and  236 . The apparatus  210  also includes a top  242 , a second plate  248  and two tilt members  244  and  246  which are attached to the top plate  242 . These tilt members  244 ,  246  have one surface that is flat and an opposing surface that is arcuate, so that they provide substantial tilt control adjustment about the rotational Z axis. Also included is a centering piece attached to the second plate  248  to prevent the top plate  243  from sliding along the Z axis. 
     While the instant invention has been shown and described herein in what are conceived to be the most practical and preferred embodiments, it is recognized that departures may be made by one of ordinary skill in the art, and it is intended that the appended claims cover all such departures and modifications to the extent that they fall within the true spirit and scope of this invention.