Abstract:
The present invention provides an apparatus for guiding a medical instrument. The medical apparatus includes a bracket member having a cavity dimensioned and configured to receive at least a portion of a medical instrument. A carriage member is slidably connected to a base assembly adapted to move the carriage member into an imaging position. The carriage assembly is adapted to rotationally support the bracket member, as well as provide a vertically adjustable height of the bracket member. A quick release member is operatively associated with the bracket and carriage members for removably attaching and detaching the bracket member to and from the carriage member when the carriage member is in the imaging position without losing the position and orientation of the carriage member.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C § 119 (e) of U.S. Provisional Patent Application No. 60/401,830, filed Aug. 7, 2002, entitled ULTRASOUND PROBE SUPPORT AND STEPPING DEVICE, the entirety of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to support apparatus for precision medical instruments, and more particularly to an adjustable support and stepping device for use with transrectal ultrasound imaging probes and a template grid or matrix. 
     BACKGROUND OF THE INVENTION 
     Brachytherapy (radioactive seeds), thermotherapy (heating), and cryotherapy (freezing) are proven therapies for tumors, both benign and malignant. Although the effectiveness of these treatments has been established, the risks associated with these treatments prevent or at least inhibit the wide application that they might otherwise achieve. The risks in each instance are related to the difficulties in achieving full control and accurate monitoring of the treatment. The risks of damaging surrounding tissues are present in every case, potentially catastrophic and require great care and experience to control. 
     In this regard, these therapies are frequently performed in conjunction with an ultrasound imaging probe placed in the rectum to monitor treatment. A template grid arrangement, which is kept in precise linear orientation with the ultrasound probe, must be accurately oriented adjacent the perineum in relation to the prostate, and locked in position throughout the procedure to achieve optimum results. Precise and reproducible orientation and positioning of the ultrasound imaging probe in the rectum is a key element in the clinical application of these therapies. 
     A number of prior art devices provide the necessary orientation and positioning. For example, U.S. Pat. No. 5,931,786, the contents of which are incorporated herein by reference, discloses a template grid support or mount and an ultrasound probe support (collectively referred to as a stepper) with a stepping function for precision axial longitudinal movement and rotation of an ultrasound probe. During a procedure, the ultrasound probe is manually inserted into the rectum and, once the desired orientation is achieved as viewed and confirmed by the monitored ultrasound images, the probe is connected to the stepper (which is typically attached to a support stand). Alternatively, if the support stand has suitable mobility, the stepper and probe can be attached to the support stand before insertion into the rectum. With the support stand set in a fixed mode, a range of positively controlled microadjustments may be used to achieve an ideal probe or instrument orientation for starting the procedure. 
     The template grid mount supports a needle guiding template grid which may be moved longitudinally along the centerline axis of the ultrasound probe while keeping a constant radial distance from this same axis. The stepping function allows precise, independent, and reproducible longitudinal movement of the ultrasound probe while keeping it in accurate radial position in relation to the grid. The rotation function of the stepper permits free axial rotation of the ultrasound probe and easy placement and removal of the ultrasound probe from the stepping device while retaining position of the stepping function and the template grid. 
     Thus, the stepper allows rotation and longitudinal movement along the axis of the ultrasound probe. However, no vertical adjustments of the ultrasound probe with respect to template grid is possible. Such vertical adjustments could be advantageous for improving treatment efficacy and safety. As previously noted, the major concern and risk of morbidity from cryotherapy and thermotherapy is thermal damage to the rectal area. This worry often limits effective treatment at the posterior margins of the prostate. In the case of cryotherapy, freezing this area is required and if the freezing is too aggressive a postoperative fistula from the prostate to the rectum may result from also freezing the rectal wall. 
     These concerns have been dealt with clinically by using a number of techniques to reduce pressure on the anterior rectal wall, thereby improving blood flow and decreasing the chances of freezing this vital area: removing the ultrasound probe during freezing or; placing weights on the probe to pull it posteriorly away from the anterior rectal wall during freezing. The latter technique is preferred because it maintains some ultrasound visibility. These techniques may be enhanced by injecting warm saline into the rectum during freezing of the prostate or by injecting fluid in the potential space between the posterior prostate and anterior rectal wall to create additional separation prior to freezing the prostate. However, all these current methods for improving safety require actively moving the ultrasound probe away from the anterior rectal wall using methods that are clumsy, time consuming and that significantly compromise good visibility using the ultrasound image. The proposed invention described herein provides a convenient, controlled and safe method for moving the ultrasound probe away from the anterior rectal wall when desired with minimal compromise of the ultrasound images and no disruption of the surgical field, as well as exact restoration of the initial imaging position at the completion of the freezing cycle. 
     As the previous discussion illustrates, a need for an improved stepper exists. 
     SUMMARY OF THE INVENTION 
     The present invention provides a medical apparatus for guiding a medical instrument. The medical apparatus includes a base assembly having a carriage assembly slidingly mounted thereto. The carriage assembly is adapted to controllably transverse the base assembly, moving the carriage assembly into an image position. 
     A medical instrument mount is rotatably mounted to the carriage assembly, wherein the medical instrument mount is configured to receive a medical instrument. Additionally, the medical instrument mount is mounted to the carriage assembly, such that the height of the medical instrument mount is adjustable on the carriage assembly. The rotatable mounting of the medical instrument mounts enables the medical instrument to be rotated about it longitudinal axis, without have to adjust the positions of the carriage assembly or the medical instrument mount. 
     A quick release member is operatively associated with the medical instrument mount and carriage assembly. The quick release member enables the medical instrument mount to be quickly and easily mounted to and removed from the carriage assembly when the carriage assembly is in the imaging position without losing position and orientation of the carriage assembly. The quick release member includes a grooved portion of the carriage assembly and a tongued portion of the medical instrument mount, the grooved portion configured and dimensioned to receive the tongued portion and the tongued portion releasable from the grooved portion by rotation of the medical instrument mount with respect to the carriage assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: 
         FIG. 1  is a perspective view of one embodiment of the ultrasound probe mount and stepping device according to the present invention, wherein the ultrasound probe mount is in a neutral position; 
         FIG. 2  is a perspective view of the ultrasound probe mount and stepping device of  FIG. 1  showing the ultrasound probe mount rotated through 90 degrees clockwise as viewed from the neutral position shown in  FIG. 1 ; 
         FIG. 3  is a perspective view of the ultrasound probe mount and stepping device of  FIG. 1  showing the ultrasound probe mount rotated through about 90 degrees counterclockwise with respect to the neutral position shown in  FIG. 1 ; 
         FIG. 4  is an enlarged perspective view in partial section of the ultrasound mount and carriage of the stepper of  FIG. 1 ; 
         FIG. 5  is an elevation view of one end of the ultrasound probe mount; 
         FIG. 6  is a perspective view of another embodiment of the device of the present invention which includes an ultrasound probe mount in a neutral position; 
         FIG. 7  is a perspective view of the ultrasound probe mount and stepping device of  FIG. 6 ; 
         FIG. 8  is a perspective view of another embodiment of an ultrasound probe mount and stepping device according to the present invention with a carriage in a first vertical position; 
         FIG. 9  is a perspective view of the device of  FIG. 8  with the carriage in a second vertical position; 
         FIG. 10  is a perspective view from one side of another embodiment of a carriage according to the present invention with the carriage in a first vertical position; 
         FIG. 11  is a perspective view from another side of the carriage of  FIG. 10  with the carriage in a second vertical position; 
         FIG. 12  is a perspective view from one side of another embodiment of a carriage according to the present invention with the carriage in a first vertical position; and 
         FIG. 13  is a perspective view from another side of the carriage of  FIG. 10  with the carriage in a second vertical position 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the description which follows, any reference to either direction or orientation is intended primarily and solely for purposes of illustration and is not intended in any way as a limitation to the scope of the present invention. Also, the particular embodiments described herein, although being preferred, are not to be considered as limiting of the present invention. 
     Referring now to the drawing figures in which like reference designators refer to like elements, there is shown in  FIG. 1  the device  10  according to the present invention. The device  10  of the present invention includes an ultrasound probe mount  12 , a carriage  14 , a base assembly  16 , and a template grid mount  18 . The probe mount  12  is adapted to receive and securely clamp around a central enlarged portion of an ultrasound probe. This probe mount  12  is held for rotation within carriage  14 . The carriage  14  is, in turn, held for slidable longitudinal movement along the base assembly  16  and the template grid mount  18  is adapted to supportively secure a template grid  70  thereatop. 
     With respect to the rotation and longitudinal motions, the structure, function, and operation of device  10  is analogous to the steppers disclosed in U.S. Pat. No. 5,931,786, the contents of which are incorporated herein by reference. 
     With more specific detail of the components of the invention  10  discussed herebelow, and referring additionally to  FIGS. 2 and 3 , the ultrasound probe mount  12  (with ultrasound probe removed) is manually rotatable against an adjustable friction member back and forth in the direction of arrows B and C through about 90 degrees rotation in either direction from the neutral position of the ultrasound probe mount  12  shown in  FIG. 1 . As seen in  FIG. 3 , a cavity  36  is provided as clearance for tightening knob  28  which secures a pivotally connected closure strap  26  for securement of the ultrasound probe therewithin as described more fully herebelow. By this arrangement, the ultrasound probe mount  12  is fully rotatable through about 180 degrees of movement from one extreme to the other. Tightening knob  28 , closure strap  26 , and probe mount  12  are configured to allow device  10  to be used with ultrasound probes of different sizes, shapes, and manufacture. 
     The grid mount, as best seen in  FIG. 1 , is structured for securely clamping and engaging the ends of spaced apart, parallel rails  38  and  40 , by lower split flanges  64  which include holes for secure clamping engagement therebetween. The upper flange  68  includes manually tightenable fasteners  74  (typical) on each end thereof for clamping engagement with the template grid  70 . A clearance aperture formed by groove  66  in the grid mount  18  and groove  73  formed at the bottom of the template grid  70  provide for clearance access for the elongated sensing portion of the ultrasound probe. 
     The template grid  70  includes an array of apertures  72  which are precisely arranged and positioned vertically and laterally in a precise manner with respect to the longitudinal axis of the ultrasound probe when it is held within the probe mount  12 . These apertures  72  are longitudinally aligned with respect to the device  10  and are sized to receive and precisely align a needle passing therethrough having one or more spaced radioactive pellets held inside the tip of the needle. From the real time ultrasound image produced, in combination with particularly selected apertures  72 , a highly accurate placement of the radioactive seeds in the cancerous prostate is achievable. 
     Referring now to  FIGS. 4 and 5 , the details of the probe mount  12 , the carriage  14  and the base assembly  16  are shown. The probe mount  12  comprises two generally u-shaped members  19  and  20  which are held spaced apart by longitudinally oriented stainless steel pins  22  and  24 . The closure strap  26  is pivotally connected to pin  22 , the opposite end of closure strap  26  being structured for locking tightenable engagement by adjusting knob  28  with structure of the corresponding end of u-shaped channel member  19 . 
     The closely spaced facing edges of the u-shaped members  19  and  20  have a dovetail groove  104  and  106  which mateably and trappingly engages with a corresponding dovetail shape of a locking block  98 . The locking block  98  is connected to the carriage  14  by a flush mounted threaded fastener  99  which threadably engages into a threaded nylon insert  101  connected within carriage  14  as seen in  FIG. 5 . The upwardly facing concave contour of locking block  98  generally conforms with the cylindrical aligned inner surfaces of each of the u-shaped members  19  and  20 . By this arrangement, the probe mount  12  is rigidly secured within carriage  14  for rotational movement only with the frictional resistance to rotational movement controlled by the tensioning of threaded fastener  99  against locking block  98 . 
     One benefit of this structural arrangement of the probe mount  12  is to allow for at least −90° to +90° movement back and forth in the direction of arrows B and C from a neutral position of the probe mount  12 . This neutral position is physically identified by providing a detent ball plunger  92  mounted uprightly within carriage  14  and interacting with a longitudinal groove or other suitable depression  94  formed centrally along the lower outer surface of the probe mount  12 . Proper alignment of the ultrasound probe is initially established by providing one or more protuberances  96  which upwardly extend from the inner surface of the u-shaped members  19  and  20 . These protuberances  96  interact with a longitudinal groove or other suitable depression formed in most, if not all, ultrasound probe units for identifying a design orientation with respect to the probe mount  12 . For probe units having alignment pin(s) rather than a groove or depression, probe mount  12  can be provided with a groove for ensuring alignment. 
     Referring more specifically to  FIG. 5 , after the probe is inserted in probe mount  12 , the geometric center of the probe is located generally at  112  while the imaging center is located vertically upwardly at  110 . In order to compensate for this arrangement, as the probe mount  12  is rotated in the direction of either B or C, the geometric center  112  moves along arc  114  so that imaging center  110  rotates without any lateral displacement. 
     Another benefit of the structural arrangement of the probe mount  12  and carriage  14  is the ability to remove the probe mount  12  from the carriage  14  by rotation. Because the u-shaped members  19  and  20  do not form a complete circle as shown best in  FIGS. 1 and 2 , the probe mount  12  can be spun-out or off the carriage  14  until free thereof. This allows for ease of removal of probe mount  12  for cleaning purposes. In addition, this allows the probe mount  12  to be easily replaced with a new unit when inoperative. Such ease of removal and replacement of the probe without loss of position is very desirable during medical procedures should the rectum fill with gas or stool and require cleansing to restore a good ultrasound image. 
     The base assembly  16  includes two aluminum rails  38  and  40  held in spaced relation at one end by the grid mount  18 . The opposite ends of rails  38  and  40  are clampingly engaged into a first transversely oriented crossbar  50  which is clampingly secured by thumb screws  52  and  54  which squeezably engage and reduce the gaps  56  and  58  against the corresponding rails  38  and  40 . A separate crossbar  76  is also permanently attached between the corresponding ends of the rails  38  and  40 . These crossbars  46  and  50  are connected to and supported by a flat aluminum base plate  62  which is adapted to be secured to a support stand. A preferred support stand for use in this invention is shown in U.S. Pat. No. 5,961,527, the contents of which are incorporated herein by reference. The position of template grid mount  18 , and consequently template grid  70 , is adjustable by moving rails  38  and  40  using crossbar  76  as a handle when thumbscrews  52  and  54  are loosened. The ability to adjust the position of template grid  70  through the back of device  10  is another benefit. 
     The carriage  14  is slidably engaged around the rails  38  and  40  through moving longitudinal apertures formed through the lower corners of the carriage  14  as best seen in  FIG. 1 . Alternatively, a single rail can be used if desired. To control the linear longitudinal movement and secure positioning of the carriage  14  back and forth in the direction of arrow A in  FIG. 1 , an adjusting knob  32  (on one or both sides of carriage  14 ) rotatable back and forth in the direction of the arrows is connected to a coaxial gear  34  about a transverse axis with respect to the carriage  14  as also partially seen in  FIG. 4 . An elongated rack  42  having finely spaced straight teeth  44  formed along one surface thereof is connected at one end to the first crossbar  50 . The opposite end of rack  42  is secured within a second transversely oriented crossbar  46 . The rack  42  is slidably engageable within a longitudinal aperture formed through carriage  14  and positioned between the longitudinal apertures formed to slidably receive rails  38  and  40 . 
     By this arrangement of gear  34  and stationary rack  44 , by rotating the adjusting knob  32  back and forth in the direction of the arrow, movement of the carriage  14  in either direction of arrow A is effected. As best seen in  FIGS. 2 and 4 , the rack  42  also includes a series of precision spaced laterally facing dimples  80  which interact with spaced spring loaded ball plungers  86  and  88  so as to identify by feel the preselected distance of movement between each felt detent as adjusting knob  32  is rotated to effect movement of the carriage  14 . This gear, rack, and detent system achieves the stepping function required during the procedure. An alternative to knowing the exact distance of movement of the carriage  14  is provided by a fixed blade  37  positioned directly above a conventional measuring scale  78  on base plate  62  which can be viewed so as to determine the desired amount of longitudinal movement of the carriage  14 . 
     Turning now to  FIGS. 6 and 7 , an alternative embodiment of the device  210  according to the present invention is shown. In general, most of the structure shown in  FIGS. 6 and 7  is like or comparable to the structure illustrated in the embodiment shown in previous  FIGS. 1 through 5  and accordingly discussion of those like components is not believed necessary. The base plate  212  supports a tilted scale  214  positioned along each elongated side of base plate  212 . Preferably the scale  214  is tilted at about forty-five (45) degrees for ease of viewing by the medical personnel using the device of the present invention. 
     The carriage  216  is formed of two like shaped generally trapezoidal blocks  220  and  222  which are separated and kept apart by pins  224  and  226  as shown in  FIGS. 6 and 7 . The distance between blocks  220  and  222  is adjustable along pins  224  and  226 . Carriage block  220  has an indicator line  218  on each side to match up against the scales  214 . As the block moves along rods  38  and  40  the position of the carriage  216  can be measured or determined along either scale  214 . 
     The carriage  216  provides an arcuate recess that accommodates the outer curved portion of a probe mount or cradle  228  which can be formed as an integral piece or bracket with u-shaped members  230  and  232 . The closure strap  234  is pinned at one end between unshaped members  230  and  232  for pivotal rotation thereabout. At its other end the closure strap  234  can be positioned within recess  236  defined between u-shaped members  230  and  232 . Recess  236  includes a narrow portion  237 . A latch pin  238  is rotationally pinned at its one end to the other end of closure strap  234 . The other end of latch pin  238  is coupled to tightening knob  240  which can be rotationally threaded on pin  238 . After a probe is positioned within probe mount  228 , the closure strap  234  can be placed over a portion of the outer surface of the probe. The free or other end of closure strap  234  is placed in the recess  236 , the pin  238  is moved into the narrow portion  237  of recess  236 , and the tightening knob  240  is rotated on pin  238  to rest against the lower (not shown) shoulders  242  in recess  236 . The tightening knob  240  is thus oriented or positioned so that it does not interfere with the top surface of the cradle or probe mount for needle placement nor does it alter the shape of the probe cradle with clamping pressure. Probe mount  228  and in particular tightening knob  240  and closure strap  234  are configured to accommodate various ultrasound probes. The probe mount or cradle  228  also has rotation scales  242  on each side of u-shaped member  230 . If desired, rotation scales  242  can also be placed on the other u-shaped member  232 . 
     Although probe mount  228  can be freely positioned in the arcuate recess of carriage  216  for rotational movement about a longitudinal axis of device  210 , in one preferred embodiment slotted or grooved guides  244  and  246  are secured by known techniques at upper end portions of carriage  216 . The guides  244  and  246  have generally L-shaped cross-sections which fit over corresponding L-shaped grooves  248  in the ends of probe mount  228  which is thus rotationally secured to carriage  216 . In this embodiment, the locking block  98  with dovetail grooves  100  and  102  and corresponding mating structures on probe mount  12  are not needed. It is believed that the probe mount  228  is more stably retained in its rotational configuration relative to carriage  216 . In addition, because the u-shaped members  230  and  232  do not form a complete circle as shown in  FIGS. 7 and 8 , the probe mount  228  can be spun-out or off the carriage  216  until free thereof. This allows for ease of removal of probe mount  228  for cleaning purposes. In addition, this allows any broken or worn out probe mount  228  to be easily replaced with a new unit. Such ease of removal and replacement of the probe without loss of position is very desirable during medical procedures should the rectum fill with gas or stool and require cleansing to restore a good ultrasound image. 
       FIGS. 8 and 9  show another embodiment of a device  510  according to the present invention. In general, most of the structure shown in  FIGS. 8 and 9  is like or comparable to the structure illustrated in the embodiments shown in  FIGS. 1-7  and accordingly discussion of those like components is not believed necessary. Unlike carriage  14 , a carriage  514  includes a first member  600  and a second member  602 . Second member  602  includes a recess  604  for receiving an ultrasound probe. In this regard, second member  602  can be provided with a probe mount analogous to probe mount  12  for securing the ultrasound probe in a manner that allows rotational movement of the probe. First member  600  is coupled to the rest of device  510  in a manner analogous to carriage  14  to provide for controlled longitudinal movement of first member  600 . 
     First and second members  600 ,  602  are coupled so that the vertical position of second member  602  with respect to first member  600  can be adjusted. Specifically, one end of each of first legs  606  is pivotally connected to first member  600  and the other end of each of first legs  606  is pivotally connected to connecting bars  608  (only one of which is visible in  FIGS. 8 and 9 ). Similarly, one end of each of second legs  610  is pivotally connected to second member  602  and the other end of each of second legs  610  is pivotally connected to connecting bars  608 . First and second legs  606 ,  610  and connecting bars  608  provide a scissor-like mechanism. As a result, second member  602  can be moved up or down with respect to first member  600 . 
     In one embodiment, the operator simply grasps second member  602  or the ultrasound probe, which is fixed with respect to second member  602 , to effect the vertical movement. The pivotal connections between first and second legs  606 ,  610  and connecting bars  608  can be made to have sufficient resistance to maintain the vertical position of second member  602 . Alternatively, a locking element, such as a tightening knob located on one of the connecting bars  608 , can be provided. In another embodiment, the vertical movement of the second member  602  can be controlled by a worm gear or other mechanism (like that used in an automotive jack) so that more precise movement of second member  602  can be achieved. 
     In this regard,  FIGS. 10 and 11  show another embodiment of a carriage  700 . The rest of the stepping device is not shown for clarity, but would be analogous to that used with carriage  14 ,  514 . Accordingly, discussion is not believed to be necessary. Carriage  700  includes a first member  702  and a second member  704 . First member  702  is coupled to the rest of the stepper in a manner analogous to carriage  14  to provide for controlled longitudinal movement of first member  702  and has a knob  706  for affecting this longitudinal movement. A probe mount  712  analogous to probe mount  12  for securing the ultrasound probe in a manner that allows rotational movement of the probe. 
     Second member  704  comprises a left housing  714  and a right housing  716 . As explained in more detail, left and right housings  714 ,  716  can move toward and away from each other and are coupled to probe mount  712  so that this movement is translated into vertical movement of probe mount  712 . Left and right housings  714 ,  716  each have a threaded bore for receiving a threaded rod  718  that extends through left and right housings  714 ,  716 . Threaded rod  718  has a vertical control knob  720  at one end. Thus, rotation of knob  720  results in rotation of rod  718 . Rotation of knob  720  in one direction causes rod  718  to rotate in the same direction and left and right housings  714 ,  716  to move toward each other. Rotation of knob  720  in the other direction causes rod  718  to rotate in the same direction and left and right housings  714 ,  716  to move away from each other. 
     Each of left and right housings  714 ,  716  includes an oblique slot  722  in which a bar  724  can travel. Probe mount  712  includes a yoke  726  and each arm of yoke  726  has an aperture through which bar  724  extends. As bars  724  travel in slots  722  (caused by the movement of left and right housings  714 ,  716  toward or away from each other), yoke  726  is carried with bars  724 , thereby resulting in vertical movement of probe mount  712 . 
     Yoke  726  includes one or more fins  728  that move up or down in a groove (or grooves)  730  provided in first member  702 . This provides stability to probe mount  712  during vertical movement. Each of left and right housings  714 ,  716  includes a horizontal slot  732  and first member  702  includes two apertures. A bar  734  extends through each slot  732  and aperture. The cooperation of slots  732 , bars  734 , and the apertures in first member  702  helps ensure that rotational movement of threaded rod  718  is translated into lateral movement of left and right housings  714 ,  716 . Slots  732  also limit the extent of lateral movement of left and right housings  714 ,  716 . Similarly, slots  722  limit the vertical movement of probe mount  712 . 
     Referring to  FIGS. 12 and 13  the carriage  800  includes a first member  802  and a second member  804 . First member  802  is coupled to the rest of the stepper in a manner analogous to carriage  14  to provide for controlled longitudinal movement of first member  802  and has a knob  806  for affecting this longitudinal movement. The first member  802  includes a slotted section  808  configured for receiving a top section  810  of the second member  804 . 
     Second member  804  comprises a left housing  812  and a right housing  814 . As explained in more detail, left and right housings  812 ,  814  can move toward and away from each other and are coupled to probe mount  816  so that this movement is translated into vertical movement of probe mount  816 . The probe mount  816  is analogous to probe mount  12  for securing the ultrasound probe in a manner that allows rotational movement of the probe. 
     Left and right housings  812 ,  814  each have a threaded bore for receiving a threaded rod  818  that extends through left and right housings  812 ,  814 . Threaded rod  818  has a vertical control knob  820  at one end. Thus, rotation of knob  820  results in rotation of rod  818 . Rotation of knob  820  in one direction causes rod  818  to rotate in the same direction and left and right housings  812 ,  814  to move toward each other. Rotation of knob  820  in the other direction causes rod  818  to rotate in the same direction and left and right housings  812 ,  814  to move away from each other. 
     Each of left and right housings  812 ,  812  includes a pair of plate members  822 , each having an oblique slot  824  in which a bar  826  can travel. Probe mount  816  includes a yoke  828  and each arm of yoke  828  has an aperture through which bar  826  extends. As bars  826  travel in slots  824  (caused by the movement of left and right housings  812 ,  814  toward or away from each other), yoke  828  is carried with bars  826 , thereby resulting in vertical movement of probe mount  816 . 
     Yoke  828  includes one or more fins  830  that move up or down in a groove (or grooves)  832  provided in first member  802 . This provides stability to probe mount  816  during vertical movement. 
     The probe mount  816  further includes a guide member  834  configured for receiving an ultrasonic probe. The guide member  834  includes a pair of substantially parallel rods  836  extending from the probe mount  816 . A probe support  838  is mounted to the distal end of the parallel rods  836 , wherein the probe mounted  838  is configured to support a portion of an ultrasonic probe. The guide member  834  assists in maintaining the alignment of the ultrasonic probe as the probe mount  816  is moved in the vertical and horizontal directs. 
     All of the components of these devices can be made from metal. According to one embodiment, the components can be machined. Alternatively, many of the components can be fabricated or cast of a plastic, with engineering thermoplastics, such as DELRIN, being exemplary. Nylons, polycarbonates and like materials can be used, if desired. 
     The features of these devices according to the present invention include: lightweight, improving the “feel” and safety when manipulating the probe in the rectum; firm and positive stepping function preventing slippage; easy to read carriage scales; rotational capability of at least 180 degrees with easy to read marking scales from either side; audible and palpable secure centerline detent featuring smooth, clockwise and counterclockwise rotation; grid movement independent of the ultrasound probe controlled from a convenient backside location; standard template grid for needles spaced in 5 mm increments with graphics and elevations specific for each brand of ultrasound (custom grid configurations can also be employed, as desired); and an open configuration and easy separability of components allowing for convenient cleaning and maintenance. 
     Additionally, the vertical adjustment mechanism allows the operator to pull the ultrasound probe away from the anterior rectal wall (lowering in relation to the template grid) in a controlled and accurate manner. This is performed while keeping the template grid fixed in relation to the patient and after the freezing or heating is completed to accurately return the ultrasound probe to its original position in relation to the template grid and patient. This permits better visualization during the procedure, greater safety, and better control of the therapy being administered. 
     While various embodiments of the present invention are described above, it should be understood that the various features could be used singly or in any combination thereof. Therefore, this invention is not to be limited to only the specifically preferred embodiments depicted herein. 
     Further, it should be understood that variations and modifications within the spirit and scope of the invention might occur to those skilled in the art to which the invention pertains. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is accordingly defined as set forth in the appended claims.