Abstract:
An adjustable profile probe for insertion in a body cavity to sense a biological parameter includes an elongated shaft having a sensor panel and a resiliently expandable portion substantially opposing the sensor panel. An expansion mechanism is at least partially housed within the elongated shaft for varying the profile of the probe. The expansion mechanism includes a base plate adjacent to the resiliently expandable portion and a plurality of lever arms pivotally mounted to the base plate and the sensor panel. An actuating member pivotally connects to the lever arms such that upon movement of the actuating member, the resiliently expandable portion is selectively collapsed or expanded by the plurality of lever arms pivoting between a minimal profile position near parallel with the elongated shaft and an expanded profile position with the lever arms being near perpendicular to the elongated shaft.

Description:
TECHNICAL FIELD 
     The disclosed technology generally relates to monitoring a biological parameter after insertion of a medical device or a portion of the medical device into a body cavity and, more particularly, to a probe with an adjustable profile to allow collapsing for more comfortable and easier insertion into the body cavity and then expansion after placement within the body cavity. 
     BACKGROUND INFORMATION 
     The prostate gland is part of the male reproductive system. It consists of two lobes in front of the rectum and just below the bladder. The prostate gland also surrounds the urethra, the canal through which urine passes out of the body. The prostate gland has two main periods of growth. The first growth period is during puberty. However, during a man&#39;s mid-twenties, the prostate gland begins to grow again and continues to do so for the remainder of life. As the prostate gland grows, several problems often occur as a result of excessive growth. Rarely do such afflictions occur before forty, but as a man&#39;s age increases, the likelihood of prostate gland afflictions increases significantly. 
     Benign Prostate Hyperplasia (BPH) is the later growth of the prostate gland causing symptoms such as pain, frequent urination and inability to drain the bladder. Fortunately, a digital rectal exam can often lead to early detection of BPH and several effective treatment modalities exist. For example, drugs such as finasteride, transurethral microwave procedures, transurethral needle ablation, and surgical treatments are available. 
     Several approaches to treatment by heating the prostate are known. See, for example, U.S. Pat. Nos. 6,477,426, 6,592,579, 6,402,742, 6,142,993, 5,865,788, 5,385,544, 6,490,488, and 6,895,282. Such known heat treatments have difficulty in targeting the prostate without heating the urethral and rectal walls, which can result in destroying healthy tissue. As a result, monitoring of the temperature of the prostate and surrounding areas is critical to successful procedures. In order to measure accurately the rectal wall temperature and, thereby, monitor the prostate temperature as well, it is necessary that the rectal probe be of sufficient size to press against the rectal wall at the appropriate location. However, such size causes pain and discomfort upon insertion, while after insertion, discomfort is often negligible. Known techniques for monitoring internal temperature, such as those disclosed in U.S. Pat. Nos. 6,348,039, 5,792,070, 5,404,881, 6,475,140, 6,868,290, and 4,046,139, can provide not only poor performance but also discomfort during insertion and complexity of operation. 
     SUMMARY OF THE INVENTION 
     The invention generally relates to a probe that is easily inserted into the body of a patient (such as a human or other mammal) and that is comfortable to the patient during insertion, use, and removal, while still effectively engaging an internal wall within the body after insertion into the body. The probe, or at least a portion of the probe, is expandable and collapsible. When collapsed, the probe is insertable into a cavity of the patient&#39;s body without causing the patient undue pain or discomfort. After insertion into the cavity, the probe or a portion of the probe can be expanded. After use, the expanded probe or probe portion can be collapsed and easily removed from the patient&#39;s body, again without causing the patient undue pain or discomfort. In one embodiment, the probe is a rectal probe and it includes one or more temperature sensors on its expandable/collapsible portion for sensing rectal wall temperature when in place within the rectum of the patient. The temperature of the rectal wall provides a useable and reliable measure of the temperature of the prostate of the patient. 
     In one illustrative embodiment according to the invention, a rectal probe is easily and comfortably inserted into the rectum of a patient and also expands after insertion to provide efficacious readings within the rectum, such as temperature readings. The rectal probe has an adjustable profile and is designed to be inserted into the rectum or some other body cavity of a human (or other mammal) patient. The probe can include one or more sensors for sensing at least one biological parameter (such as temperature) within the body cavity. The probe can include an elongated shaft with a sensor panel and a resiliently expandable portion that is substantially opposing the sensor panel. An expansion mechanism can be at least partially housed within the elongated shaft. This mechanism is for varying the profile of the probe, and it can include a base plate adjacent to the resiliently expandable portion, a plurality of lever arms pivotally mounted to the base plate, and the sensor panel. An actuating member pivotally connects to the lever arms such that, upon movement of the actuating member, the resiliently expandable portion is selectively collapsed or expanded by the plurality of lever arms pivoting between a minimal profile position parallel or near parallel with the elongated shaft and an expanded profile position with the lever arms being perpendicular or near perpendicular to the elongated shaft. The actuating member can have a plurality of bar links, and the resiliently expandable portion can be made of silicone, latex, and/or nitrile rubber, for example. The resiliently expandable portion can have a varying thickness, and it can have at least one lever arm pivotally mounted to the rigid portion. 
     In one aspect, the invention generally relates to an adjustable profile probe for insertion in a body cavity to sense a biological parameter. The probe comprises an elongated shaft defining an interior. The elongated shaft includes a proximal end, a closed distal end, a rigid portion, and a resiliently expandable portion substantially opposing the rigid portion. The probe also comprises at least one sensor mounted on the rigid portion for generating a signal corresponding to the biological parameter. The probe also comprises an expansion mechanism that is at least partially housed within the interior. The expansion mechanism includes a base plate, at least one lever arm, and an actuating member. The base plate is disposed adjacent to the resiliently expandable portion. The at least one lever arm includes a first end pivotally mounted to the base plate and a second end disposed adjacent to the rigid portion. The actuating member is pivotally connected to the at least one lever arm and extends toward the proximal end such that, upon movement of the actuating member towards the closed distal end, the resiliently expandable portion expands and, upon movement towards the proximal end, the resiliently expandable portion is allowed to collapse. 
     Embodiments according to this aspect of the invention can include the following features. The actuating member can include a plurality of bar links. The resiliently expandable portion can be made of silicone, latex, nitrile rubber, or other material(s) that are biocompatible and expandable. The resiliently expandable portion can have a varying thickness. The at least one lever arm can be pivotally mounted to the rigid portion. The rigid portion can be on or near the closed distal end. The at least one sensor can comprise a sensor panel that includes a plurality of the sensors. 
     In another aspect, the invention generally involves a mechanism for varying a profile of a probe having a sensor panel. The mechanism comprises an expandable portion, at least one arm pivotally mounted to the probe adjacent the expandable portion, and means attached to the at least one arm for moving the at least one arm between a first position, where the profile of the probe is substantially minimized, and a second position, where the at least one arm presses the expandable portion and thereby causes the profile of the probe to enlarge. 
     Embodiments according to this other aspect of the invention can include the following features. The expandable portion can be substantially opposing the sensor panel. The sensor panel can include at least one temperature sensor. A base plate can have the at least one arm pivotally coupled thereto. The means can be at least one bar link or a screw drive actuator. 
     In yet another aspect, the invention generally features a mechanism for varying a profile of an elongated rectal probe having a sensor. The mechanism comprises an expandable portion having the sensor mounted adjacent thereto. The mechanism also comprises means, at least partially within the expandable portion, for selectively urging the expandable portion radially outward. 
     Embodiments according to this other aspect of the invention can include various features. For example, the means can be a linkage mechanism or a flexure member. 
     In still another embodiment, the invention generally relates to a mechanism for varying a profile of an elongated rectal probe having a sensor. The mechanism comprises an expandable portion, an arm pivotally mounted to the rectal probe adjacent the expandable portion, and a linkage shaft attached to the arm for moving the arm from a first position in which the expandable portion is relaxed and a second position in which the expandable portion is extended. 
     Embodiments according to this other aspect of the invention can include various features. For example, the expandable portion can have a thickness that varies to determine the profile of the elongated rectal probe in the second position, and a base plate with the arm mounted thereto can be provided. 
     These and other aspects, features, advantages, and benefits according to the invention are described and shown elsewhere herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing discussion will be understood more readily from the following detailed description of the disclosed technology, when taken in conjunction with the accompanying drawings in which: 
         FIG. 1  illustrates a rectal probe for sensing temperature at the prostate in accordance with the subject technology, and in particular a sectional view of a patient having a BPH device and the rectal probe fully disposed in an operational position; 
         FIG. 2A  is a perspective view of the rectal probe of  FIG. 1 ; 
         FIG. 2B  is an exploded perspective view of the rectal probe of  FIG. 1 ; 
         FIG. 3A  is an assembled partial cross-sectional side view of the collapsed rectal probe of  FIG. 1 ; 
         FIG. 3B  is an assembled cross-sectional end view of the collapsed rectal probe of  FIG. 3A  taken along line  3 B; 
         FIG. 4A  is an assembled cross-sectional side view of the expanded rectal probe of  FIG. 1 ; 
         FIG. 4B  is an assembled cross-sectional end view of the expanded rectal probe of  FIG. 4A  taken along line  4 B; 
         FIG. 5A  is a cross-sectional side view of the distal end of another rectal probe, in a collapsed state, in accordance with the disclosed technology; 
         FIG. 5B  is an assembled cross-sectional end view of the collapsed rectal probe of  FIG. 5A  taken along line  5 B; 
         FIG. 6A  is a cross-sectional side view of the distal end of the rectal probe of  FIG. 5A  in an expanded state; 
         FIG. 6B  is an assembled cross-sectional end view of the expanded rectal probe of  FIG. 6A  taken along line  6 B; 
         FIG. 7  is an assembled view of the rectal probe of  FIG. 1  in preparation for insertion into a patient; and 
         FIG. 8  is an assembled view of the rectal probe of  FIG. 1  being expanded in a patient after insertion. 
     
    
    
     DESCRIPTION 
     Unless otherwise specified, the illustrated embodiments contain exemplary features of varying detail of certain embodiments according to the invention, and therefore, unless otherwise specified, features, components, modules, elements, and/or aspects of the disclosed embodiments can be otherwise combined, interconnected, sequenced, separated, interchanged, positioned, and/or rearranged and still be within the scope of the invention. Additionally, the shapes and sizes of components are exemplary and, unless otherwise specified, generally can be altered without materially affecting or limiting the invention. The term “substantially” can indicate a precise relationship, condition, arrangement, orientation, and/or other characteristic, as well as deviations thereof to the extent that such deviations do not materially impact the disclosed subject matter, as is understood by one of ordinary skill. 
     In brief and broad overview, the invention generally relates to a profile of a medical device, or a portion of a medical device, that can be adjusted to make it larger or smaller. The disclosed technology can be used to sense a biological parameter such as temperature within a body. An embodiment of a device according to the invention can be inserted into a cavity of the body while the device or a portion of it is in a collapsed state. After insertion into the body, the device or the portion of the device can be expanded or enlarged to, for example, place one or more temperature sensors closer to or in contact with an interior surface of the body cavity to allow temperature readings to be taken. The length and girth of the device or the portion of the device may be modified to allow for readings within the esophagus, ear canal, urethra, sinus passages, and/or other locations within the body of a human patient or the body of another mammal. In one illustrative embodiment, the disclosed technology is used to take temperature, humidity, and/or physiological activity readings like heartbeat, and/or to deliver direct treatment such as heat, a seed, microwave energy, ablation, and/or other types of treatment within the body. 
     In one embodiment, an adjustable profile probe according to the invention is used to sense prostate temperature during a BPH surgical procedure. An exemplary probe that may be used by inserting it into the rectum of a human (or other mammal) patient to monitor prostate temperature during a BPH procedure is shown in  FIG. 1  and referred to generally by the reference numeral  100 . A thermal device  300  is inserted into the urethra to perform the BPH procedure. The probe  100  is inserted to place sensors  102  (see  FIG. 2 ) against an area to monitor the temperature in a region. The monitored region can be the prostate “p”, and this can be accomplished by inserting the probe  100  in the rectum “r” as shown. When deployed, the medical practitioner aligns the probe  100  such that the sensors  102  are firmly placed against the rectal wall. An expansion mechanism, as described in detail below, presses the sensors  102  against the rectal wall. The probe  100  can be sized and configured to be locked in place with the sensors against the rectal wall near the prostate “p”. 
     The Probe 
     Referring now to  FIGS. 2A and 2B , perspective and exploded views of the probe  100  are shown, respectively. The sensors  102  mount on a panel  104  that is rigid and engaged to the rectal wall by an expansion mechanism. The sensor panel  104  can have four sensors  102  for providing a plurality of different readings of the rectal wall and, thereby, the prostate “p” as well. Signals from the sensors  104  are carried through leads  105  (only one shown for simplicity) to a rectal thermometry unit for readout for the medical practitioner. 
     The probe  100  includes an elongated shaft  106  having the sensor panel  104  mounted thereon and defining an interior for housing the expansion mechanism. Although the elongated shaft  106  is flexible (i.e., of a hardness on the Shore A scale of less than about 90) for contouring to the rectum “r”, the sensor panel  104  is relatively rigid to effectively press the sensors  102  against the rectal wall. In one embodiment, the length of the elongated shaft  106  is such that upon insertion up to a disk  108  mounted thereon, the sensor panel  104  is in the proximity of the prostate “p”. In another embodiment, the elongated shaft  106  includes markings or indicia to allow the medical practitioner to visually read a depth of insertion. A distal end cone  110  of the probe  100  can be frusto-conically shaped to ease insertion or can be some other shape that makes insertion easy for the person inserting the probe  100  and comfortable for the patient receiving the probe  100 . The distal end cone  110  is also fabricated from relatively rigid material. The distal end cone  110  also defines holes (not shown) for receiving alignment pins  128  formed on the rigid panel  104  to help retain the rigid panel  104  in place. A collar  130  can couple the distal end cone  110  to the distal end  120  of the probe  100 . 
     The expansion mechanism largely fits within the interior of the elongated shaft  106 . The expansion mechanism includes an elastomeric boot portion  112  substantially opposing the sensor panel  104 . The elastomeric boot portion  112  can be fabricated from silicone, latex, nitrile rubber, combinations thereof and the like, as would be appreciated by those of ordinary skill. Underneath the elastomeric boot portion  112  are a pair of base plates  114  disposed parallel to the elongated shaft  106 . Two pairs of follower arms  116  pivotally mount to each base plate  114  on one end by pins  118 . A distal end  120  of the elongated shaft  106  has hubs  122  for pivotally coupling to the other end of the follower arms  116 . The distal end  120  is sized and configured to support the rigid portion  104  and follower arms  116 . In another embodiment, the follower arms  116  mount directly to the sensor panel  104  such that the elongated shaft  106  is not necessary in the distal end  120 . 
     A shoulder  124  also couples the sensor panel  104  to the elongated shaft  106 . The shoulder  124  changes the profile of the probe  100  so that the sensor panel  104  and, thereby, the sensors  102  protrude from probe  100 . It is envisioned that the shoulder  124  can be integrally formed with the elongated shaft  106  but many other suitable configurations are possible as would be appreciated by those of ordinary skill in the pertinent art. The shoulder  124  also defines holes  126  for receiving alignment pins  128  formed on the rigid panel. 
     An elongated coupler linkage  132  extends through the elongated shaft  106  to pivotally couple to slots  133  formed in the follower arms  116 . Pins  135  can be free to move within the slots  133 . A bushing  134  surrounds the coupler linkage  132  within the elongated shaft  106  to facilitate axial motion of the coupler linkage  132  within the elongated shaft  106 . A ferule  136  attaches to the proximal end  138  of the coupler linkage  132  to act as a handle. Similarly, a complimentary ferule  139  attaches to the proximal end  140  of the elongated shaft  106  to also act as a handle for the medical practitioner. The complimentary ferule  139  can form a channel  142  to allow the leads  105  to exit the elongated shaft  106 . In another embodiment, the elongated coupler linkage  132  is a screw drive mechanism, one or more bar linkages, or the like, as would be appreciated by those of ordinary skill. 
     The Collapsed Probe 
     Referring now to  FIGS. 3A and 3B , the probe  100  is shown in cross-sectional side and end view, respectively, in a relaxed state. By relaxed state, the elastomeric boot portion  112  is minimally stressed and the diameter, as represented by arrow  140 , of the probe  100  is substantially minimized. To achieve this collapsed condition, the medical practitioner simply extracts the coupler linkage  132  from the elongated shaft  106  by ferule  136 . The extraction pulls the follower arms  116  towards the proximal end of the probe  100  whereby the follower arms  116  pivot towards parallel the elongated shaft  106 . As the follower arms  116  pivot, the base plates  114  move radially inward and the elastomeric boot portion  112  tracks the motion. 
     In some embodiments, the natural compressive force of the elastomeric boot portion  112  urges the base plates  114  radially inward. The follower arms  116  can be sized and configured to pivot substantially parallel to the elongated shaft  106 . The base plates  114  can be connected as a single arcuate structure. The thickness of the elastomeric boot portion  112  can vary to determine the profile of the probe  100  in the expanded position. Different structure can be used to perform the same function as the coupler linkage  132 . For example, alternative linkages such as chain, crank and slider, four-bar, isosceles, quick return, Whitworth, toggle, and/or moving slide linkages could be adapted for use with embodiments according to the invention. 
     The Expanded Probe 
     Referring now to  FIGS. 4A and 4B , the probe  100  is shown in cross-sectional side and end view, respectively, in an expanded state. In the expanded state, the diameter  140  of the probe  100  is increased. To achieve this expanded condition, the medical practitioner urges the coupler linkage  132  into the elongated shaft  106  by ferule  136 . The insertion pushes the follower arms  116  towards the proximal end of the probe  100  whereby the follower arms  116  pivot towards perpendicular the elongated shaft  106 . As the follower arms  116  pivot perpendicularly, the base plates  114  move radially outward and the boot portion  112  expands. 
     In another embodiment, detents or other well-known position locking mechanisms are utilized on the probe  100  and between the elongated shaft  106  and coupler linkage  132  to allow the medical practitioner to easily alternate between expanded and collapsed conditions. In still another embodiment, the coupler linkage  132  is relatively stiff and segmented into various coupled portions to allow for conforming to a body opening. 
     Another Probe 
     Referring now to  FIGS. 5A and 5B , another embodiment of the probe of the present invention is indicated generally by the reference numeral  200 . As will be appreciated by those of ordinary skill in the pertinent art, the probe  200  utilizes similar principles to the probe  100  described above. Accordingly, like reference numerals preceded by the numeral “2” instead of the numeral “1”, are used to indicate like elements whenever possible. The primary difference of probe  200  is that rather than having a coupler linkage extending through the elongated shaft  206 , an inner shaft  207  inserts therein. The inner shaft  207  has a leaf spring  209  mounted on the distal end  211  thereof. The elongated shaft  206  forms an aperture  207  adjacent the elastomeric boot portion  212 . When the inner shaft  207  is pulled away from the distal end cone  210 , the leaf spring  209  is compressed substantially flush against the inner shaft  207  within the elongated shaft  206 . As a result, the profile of the probe  200  is negligibly affected. 
     Referring now to  FIGS. 6A and 6B , when the inner shaft  207  is urged toward the distal end cone  210 , the leaf spring  209  expands through aperture  207  to press radially outward against the elastomeric boot portion  212 . As a result, the diameter of the probe  200  is expanded. In another embodiment, the leaf spring  209  extends beyond the distal end  211  of the inner shaft  207  such that the compressive force generated against the distal end cone  210  bows the leaf spring  209  radially outward against the elastomeric boot portion  212 . 
     Implantation of the Probe 
     Referring now to  FIGS. 7 and 8 , the probe  100  being deployed in the rectum “r” of a patient is illustrated. In  FIG. 7 , the probe  100  is placed in a relaxed or minimal profile state by retracting the coupler linkage  132 . A lubricant can be applied to the distal end cone  110  and otherwise as necessary to ease insertion. The medical practitioner inserts the relaxed probe  100  into the rectum “r” until the disk  108  reaches the rectum “r” as shown in  FIG. 8 . As a result, the probe  100  places the sensor panel  104  and, thereby, the sensors  102  in the portion of the rectum “r” near the prostate “p”. 
     Upon insertion to the appropriate depth, the medical practitioner urges the coupler linkage  132  towards the distal end cone  110  to activate the expansion mechanism. As the follower arms  116  pivot, the base plates  114  are urged radially outward and the elastomeric boot portion  112  expands outward such that the cross-sectional dimension of the probe  100  is increased. The expansion of the diameter of the probe  100  locks the probe  100  in place with the sensors  102  pressed against the rectal wall as shown in  FIG. 1 . Upon deployment, the probe  100  directly senses the temperature of the rectal wall in a plurality of locations and indirectly monitors the temperature of the surrounding area, such as the prostate. 
     The functions of various elements described herein may, in some embodiments, be carried out by more or fewer elements, including by a single element. Similarly, in some embodiments, any functional element may perform fewer, or different, operations than those described with respect to the illustrated embodiment. Also, functional elements (e.g., linkages, shafts, couplers, elastic portions, and the like) shown as distinct for purposes of illustration may be incorporated within other functional elements in a particular implementation. It is also envisioned that the disclosed probes may be adapted to monitor a plurality of parameters in any body orifice. 
     While certain illustrative embodiments according to the invention are disclosed herein, the invention is not limited to or by the disclosed embodiments. Also, various changes and/or modifications can be made to the disclosed embodiments without departing from the spirit or scope of the invention.