Patent Publication Number: US-2011071362-A1

Title: Retractor tool

Description:
PRIORITY CLAIM AND CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/245,122, filed Sep. 23, 2009. 
    
    
     FIELD 
     A field of the invention is medical and surgical tools. Example applications of the invention include retaining tissue during a medical or surgical procedure. 
     BACKGROUND 
     Surgical excision or exploration of tissue may be facilitated by various probe devices. The probe devices are generally cylindrical, and can be used for detection and differentiation of various tissues, or for detection of foreign objects that were previously inserted into the tissue. For example, a medical probe may be used to locate a radio frequency identification (RFID) chip or passive integrated transponder (PIT) tag embedded within target tissue. Alternatively, probes may be used in conjunction with measurement devices such as thermometers, Geiger counters, and other devices to collect information about the condition of the tissue at particular and relatively precise locations. 
     Once a probe device has identified a particular area of tissue that is of interest to the user, it is often necessary to retract the targeted tissue. However, a single user may find it difficult or awkward to use both a probe and a retractor at the same time. Alternatively, the process of locating target tissue with a probe, setting aside the probe to retrieve a separate retractor, and accurately retracting the target tissue identified by the probe is both difficult and time-consuming for users. Accordingly, there is a need for a retractor tool that can be easily and comfortably used in conjunction with a medical probe device. 
     SUMMARY OF THE INVENTION 
     A retractor tool for retracting target tissue is provided for use with a medical probe. The retractor tool includes a guide piece that defines a probe channel and at least one retractor arm channel. Further, the retractor tool at least one retractor arm, each retractor arm passing through a corresponding retractor arm channel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a retractor tool of some embodiments of the present invention; 
         FIG. 2  is an overhead plan view of a guide piece of the retractor tool of  FIG. 1 ; 
         FIG. 3  is a perspective view of a guide piece with a probe channel locking mechanism; 
         FIG. 4  is an elevation of an embodiment of a guide piece, showing a probe channel axis and a parallel arm channel axis; 
         FIG. 5  is an elevation is an elevation of an embodiment of a guide piece, showing a probe channel axis and an intersecting arm channel axis; and 
         FIG. 6 . is a perspective view of a retractor tool of another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention provide a retractor tool for retracting targeted tissue. The retractor tool includes a guide piece that defines a probe channel and one or more retractor arm channels. Further, the retractor tool includes a medical probe that passes through the probe channel, and one or more retractor arms, each of the one or more retractor arms passing through a corresponding one of the one or more retractor arm channels. 
     Referring now to  FIG. 1 , a retractor tool is generally designated  10 . The retractor tool  10  includes a guide piece  12  used with a medical probe  14  and including one or more retractor arms  16 . The guide piece  12  guides the positioning of the one or more retractor arms  16  relative to the medical probe  14 . 
     The guide piece  12  is preferably made from a single, solid piece of material, such as plastic, surgical stainless steel or aluminum, and may range in size from multiple millimeters to multiple centimeters. Alternatively, any material, such as a medical grade plastic, may be used to form the guide piece  12 . The guide piece  12  includes a top face  18  as shown in  FIG. 2 , a bottom face  20 , and a side wall  22  and is preferably generally cylindrical. Alternatively, the guide piece  12  may have any other three dimensional shape, or may be composed of multiple attached components that together provide for a channel for the probe  14  and one or more retractors arms  16 . 
     The guide piece  12  includes a probe channel  24  sized to allow the medical probe  14  to pass through the guide piece. The probe channel  24  preferably extends through the guide piece  12  in a direction that is generally perpendicular to the top and bottom faces  18 ,  20  of the guide piece, such that an axis P of the probe channel is substantially in parallel with an axis of the guide piece. Moreover, the probe channel  24  has a shape and size that are chosen to match the cross-sectional shape and size of the medical probe  14  with which the guide piece  12  is used. For example, when used with a medical probe having a generally circular cross-sectional shape, the probe channel  24  is generally cylindrical. Similarly, if the probe is not circular in cross-section, the guide channel  24  would not be circular, but would rather match the cross-sectional shape of the probe. Moreover, the probe channel  24  is sized so as to allow the guide piece  12  to move freely along the probe  14 , sometimes including an accommodation for a sterile probe cover, and may or may not allow rotation about the axis P ( FIG. 4 ) of the probe channel, while still maintaining a close fit. The probe channel  24  is preferably positioned at or near the center of the cross-section of the guide piece  12 , but artisans will recognize that the probe channel could be positioned elsewhere on the guide without departing from the scope of the present invention. 
     As shown in  FIG. 3 , some embodiments of the present invention include a guide piece  12  that has a locking mechanism  26  associated with the probe channel  24 . The locking mechanism  26  releasably restricts movement of the guide piece  12  relative to the medical probe  14 . For example, the guide piece  12  may include a clamping mechanism that restricts movement of the guide piece relative to the probe via friction force when the clamp is engaged. Additionally, such a clamping mechanism may also restrict rotation of the guide piece  12  about the probe channel axis P, relative to the probe  14 . An example clamping mechanism  26  includes a threaded guide hole  28  positioned to receive a transverse screw  30  that passes through a portion of the guide piece  12  and into the probe channel  24 , allowing the screw  30  to exert pressure on the probe  14  when a user tightens the screw. 
     Another possible locking mechanism  26  includes a stop positioned between the guide piece  12  and a proximal end  32  of the probe  14 . The stop restricts movement of the guide piece  12  toward the proximal end  32  of the probe  14 , while allowing for both movement of the guide piece toward a distal end  34  of the probe and rotation of the guide piece relative to the probe about the axis P. 
     Alternatively, an inner surface of the probe channel  24  could be manufactured to include threads. Then, at least a portion of the outer surface of the medical probe  14  is threaded to receive the guide piece  12 . As another option, a threaded attachment may be mounted on a conventional probe  14  to receive the threaded probe channel  24 . The mating threaded surfaces allow a user to adjust the linear position of the guide piece relative to the probe by rotating the guide piece. 
     Still other embodiments of the present invention include a guide piece  12  that is permanently affixed to the medical probe  14 . The guide piece  12  may be affixed to the probe  14  using a variety of known attachment means, including welding, chemical adhesives, and the like. Additionally, the guide piece  12  may be integrally formed with the probe  14 . Permanent affixation such as this permanently restricts movement of the guide piece  12  toward both the proximal and distal ends  32 ,  34  of the medical probe  14 , and also prevents rotation of the guide piece relative to the probe. 
     One or more arm channels  36  included in the guide piece  12  further enable passage of one or more retractor arms  16  through the guide piece. As examples,  FIG. 1  shows a guide piece  12  including two arm channels  36 , while  FIGS. 2 and 3  each show a guide piece including four arm channels. Each arm channel  36  can be formed with an axis A that is generally parallel to the top probe channel  24 , and thus is generally parallel with the probe axis P, as shown in  FIG. 4 . Alternatively, the axis A of each arm channel  36  may intersect with the probe channel axis P so that the axes A and P converge at a point external to the guide piece  12  forming an angle θ, either above the top face  18  or below the bottom face  20 , as shown in  FIG. 5 . When the arm channel  36  has an angled axis A, the angle formed between the axis A of the arm channel and the axis P of the probe channel is preferably in a range of approximately 0° to approximately 30°. Thus, one or more of the retractor arms may be guided to converge or diverge relative to the probe&#39;s distal end. 
     The arm channels  36  are preferably spaced regularly in a circular pattern surrounding the probe channel  24 . Alternatively, the pattern formed by the arm channels  36  may be the same shape as the top and bottom faces  18 ,  20  of the guide piece  12 , or any other shape that is desirable for orienting the retractor arms  16 . Further each of the arm channels  36  has a shape and size chosen to match the cross-sectional shape and size of the retractor arms  16 , which preferably have a diameter in a range from less than 1 mm to several millimeters. That is, each of the arm channels  36  is sized such that a corresponding retractor arm  16  fits closely in the channel. 
     The medical probe  14  attached to the retractor tool  10  has proximal end  32  and distal end  34 . The distal end  34  of the probe  14  includes a sensor (not shown) that monitors at least one input, as is known in the art. For example, the sensor may be an RFID reader, a Geiger counter, a metal detector, or any similar sensor useful for determining a location of target tissue for retraction, sampling, or the like. The proximal end  32  of the probe  14  is manipulated by a user such that the sensor is passed over a portion of tissue to determine a location of target tissue. 
     The retractor tool  10  further includes one or more retractor arms  16  that are used for restraining or retracting target tissue. The retractor arms  16  are preferably relatively long and thin, linear, wire-like parts having a generally cylindrical shape. Alternatively, the retractor arms  16  may be formed with other cross-sectional shapes, such as square, hexagonal, or relatively flat shapes. The arms  16  are preferably made from metals such as surgical stainless steel, but other rigid, resilient, biocompatible materials can be used in place of or in addition to metals to form the retractor arms. Each of the retractor arms  16  includes a proximal end  38  located near the user and a distal end  40  located in a position to restrain or retract target tissue. The distal end  38  preferably includes a retaining device  42  such as a barb as shown in  FIG. 1 . Alternatively, the retaining device may be a curved or angled portion, or the like that prevents target tissue from retuning to its original position until the user releases the tissue, or the entire retractor arm itself may be curved. Each retractor arm  16  can preferably be inserted into at least one arm channel  36  to allow for retracting of targeted tissue. 
     Once the retractor arm  16  is inserted into an arm channel  36 , it may be necessary and/or beneficial to the user to lock the retractor arm in place, preventing movement of the arm toward one or both of the proximal and distal ends  32 ,  34  of the medical probe  14 . Accordingly, some embodiments of the retractor tool  10  may optionally include a locking mechanism having locked and unlocked positions. The locking mechanism releasably restricts movement toward both the proximal and distal ends of the medical probe when the mechanism is in the locked position, and does not restrict movement of the arm relative to the probe when the mechanism is in the unlocked position. 
     Alternatively, as shown in  FIG. 1 , some embodiments of the retractor arm  16  include a stop  44  disposed between the proximal and distal ends  38 ,  40  of the retractor arm. The stop  44  extends radially from a surface of the retractor arm  16  and is used to control or limit the movement of the retractor arm  16  relative to the guide piece  12 . Specifically, the stop  44  helps to prevent the retractor arm  16  from travelling past a predetermined point toward the proximal end  32  of the probe  14  while not restricting movement toward the distal end  34  of the probe. The stop  44  may be a metal or plastic protrusion that has a diameter larger than that of the arm channel  36 . The stop  44  is attached to the arm  16  using an adhesive, via a welding process, or by being formed integrally with the arm. 
     As shown in  FIG. 6 , another embodiment of the retractor tool  10  may include retractor arms  16 ′ that are permanently affixed to the guide piece  12 . That is, each arm  16 ′ may be connected to the guide piece  12  by a welded joint, a chemical adhesive, by being formed integrally, or the like. Each of the retractor arms  16 ′ also includes a retaining device  42 ′ such as a barbed tip at a distal end  40 ′ of the arm. When the retractor arms  16 ′ are permanently affixed to the guide piece  12 , the arms are permanently restrained from moving towards both the distal end  32  and the proximal end  34  of the probe  14 . 
     In use, the medical probe is inserted through the probe channel and one or more retractor arms are inserted into corresponding arm channels as desired by the user. The user then operates the probe according to known techniques to locate target tissue. Once target tissue has been located, the tissue is gripped for retraction. 
     Retracting tissue can be accomplished in various ways. For example, the entire retractor tool including the probe, guide piece, and all retractor arms may be moved toward the target tissue as a single unit. Alternatively, the guide piece and retractor arms may be moved toward the distal end of the probe while the probe is held in a stationary position, or one or more individual retractor arms may be moved toward the distal end of the probe while the probe and the guide piece are held stationary. Each of these methods causes one or more retractor arms to become embedded in the target tissue, allowing the user to manipulate the tissue as required through lateral movement and/or rotation of the retractor tool, guide piece, and/or individual retractor arms. The retaining devices located at the distal end of each retractor arm helps to prevent the target tissue from returning to its initial position until the user no longer requires that the tissue be retracted. In these ways, the user can control the amount and location of target tissue that is retracted by the arms. 
     While specific embodiments of the present invention have been shown and described, it should be understood that other modifications, substitutions and alternatives are apparent to one of ordinary skill in the art. Such modifications, substitutions and alternatives can be made without departing from the spirit and scope of the invention, which should be determined from the appended claims. 
     Various features of the invention are set forth in the appended claims.