Patent Publication Number: US-2015088192-A1

Title: Tissue tensioning devices and related methods

Description:
RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 12/942,311, filed Nov. 9, 2010, which claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/259,839 filed Nov. 10, 2009 and U.S. Provisional Application Ser. No. 61/285,395 filed Dec. 10, 2009, the contents of which are hereby incorporated by reference as if recited in full herein. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to surgical devices. 
     BACKGROUND OF THE INVENTION 
     It is estimated that over 30 million musculoskeletal injuries occur every year in the United States. It is believed that over 50% of these injuries involve soft tissue tears (e.g., tendons). Unfortunately, some of these tissues will re-tear after surgical repair. For example, rotator cuff surgery has a very high rate of re-tearing (estimated at between about 20-70%). Conventionally, surgeons repair the tendons based on experience and “feel”. Various tissue grasper devices used to repair tendons are known but there remains a need for devices that can effectively measure and hold proper tension in order to promote healing of skeletal muscle and reduce the incidence of re-injury. 
     SUMMARY OF EMBODIMENTS OF THE INVENTION 
     Embodiments of the invention are directed to devices and methods for measuring (pre-load) tension applied to target tissue during surgery. 
     Some embodiments are directed to surgical devices that include: (a) a tissue grasper; (b) a tension measurement device in communication with the grasper whereby tension applied to tissue by the tissue grasper is measured; and (c) a limb mounting member configured to support the tissue grasper and releasably hold the surgical device on a limb of a patient. 
     Other embodiments are directed to surgical devices for rotator cuff repair surgeries. The devices include: (a) a soft-tissue grasper configured to pull rotator cuff tendon associated with the rotator cuff repair; (b) a tension measurement device in communication with the grasper whereby tension applied to the rotator cuff tendon by the grasper is measured; and (c) a circuit in communication with the tension measurement device configured to define a target pre-load tension. 
     Additional embodiments are directed to methods of repairing a rotator cuff injury. The methods include: (a) providing a device with a tissue grasper and a tension measurement device; (b) pulling a detached torn rotator cuff down from a retracted intrabody position using the tissue grasper; (c) measuring tension applied to the rotator cuff during the pulling step using the tension measurement device; then (d) maintaining a desired defined pre-load tension on the pulled rotator cuff using the device while affixing the rotator cuff to local bone. 
     Still other embodiments are directed to surgical devices that include tissue graspers, a tension measurement device in communication with the tissue graspers and a tissue elongation guide in communication with the tissue graspers to measure elongation of tissue held by the tissue graspers. 
     The device may include a circuit in communication with the tension measurement device configured to generate an audible and/or visual output when a target pre-load is met or exceeded. 
     The tissue graspers can be in communication with a releasably lockable gimble that can allow a user to pivot and lock the tissue graspers into a desired orientation. 
     The device may include a circuit in communication with the tissue elongation guide and the tension measurement device, the circuit configured to: (a) monitor the measured tension; (b) generate an output to a user when a target pre-load tension is approached, met and/or exceeded; and (c) measure tissue stiffness using data from the measured tension and data from the tissue elongation guide. 
     Embodiments of the invention are directed to methods of repairing a tissue injury. The methods include: (a) providing a device with a tissue grasper and a tension measurement device; (b) pulling tissue from a retracted intrabody position using the tissue grasper; (c) measuring tension applied to the tissue during the pulling step using the tension measurement device; then (d) maintaining a desired defined pre-load tension on the pulled tissue using the device while affixing the tissue to local structure. 
     The methods may further include mounting the device to a patient prior to the pulling and measuring steps; and slidably extending, retracting and pivoting the tissue graspers while the device is mounted to the patient. The measuring step can be carried out at least twice before the maintaining step, so that at least two different tension measurements are taken with the limb in at least two different positions. 
     The methods may include measuring tissue elongation of the pulled tissue using the device. 
     The foregoing and other objects and aspects of the present invention are explained in detail in the specification set forth below. 
     It is noted that aspects of the invention described with respect to one embodiment, may be incorporated in a different embodiment although not specifically described relative thereto. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination. Applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to be able to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner. These and other objects and/or aspects of the present invention are explained in detail in the specification set forth below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective view of an exemplary device (shown mounted on a patient) according to some embodiments of the present invention. 
         FIG. 2A  is a side view of the device shown in  FIG. 1  also illustrating an optional angle measurement device according to some embodiments of the present invention. 
         FIG. 2B  is a top view of the device shown in  FIG. 1 . 
         FIG. 2C  is a schematic illustration of exemplary angle positions of a limb which can be electronically measured according to some embodiments of the present invention. 
         FIG. 3  is a partial section view of a portion of the device shown in  FIG. 1  taken along line  3 - 3  in  FIG. 2B . 
         FIG. 4A  is a bottom perspective view of the device shown in  FIG. 1 . 
         FIG. 4B  is a side perspective view of the device shown in  FIG. 1 , illustrated without an outer housing. 
         FIG. 5  is a side perspective view of the device shown in  FIG. 1 , shown without the outer housing (guide) and the inner housing. 
         FIG. 6  is a top side perspective view of another embodiment illustrating the device may be hand supported. 
         FIG. 7  is a schematic illustration of another embodiment of a device which may be configured as a hand supported embodiment or as a limb-mounted embodiment according to embodiments of the present invention. 
         FIG. 8A  illustrates a tissue grasper device applying a desired pre-load “T” onto a rotator cuff while the cuff is secured in position, typically to the humerus head. 
         FIG. 8B  illustrates that, after repair, the cuff substantially maintains the desired tensile pre-load “T” applied by the tissue grasper in  FIG. 8A  according to embodiments of the present invention. 
         FIG. 9  is a schematic illustration of a device with a digital signal processor or ASIC that defines target (e.g., optimal) tensile loads for a given indication. 
         FIGS. 10A-10C  are schematic illustrations of examples of User Interfaces for the device shown in  FIG. 9 .  FIG. 10C  illustrates a graph of different angles of orientation (where used) with two lines that electronically compare tension applied to target pre-load tension according to embodiments of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     The present invention will now be described more fully hereinafter with reference to the accompanying figures, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like numbers refer to like elements throughout. In the figures, certain layers, components or features may be exaggerated for clarity, and broken lines illustrate optional features or operations unless specified otherwise. In addition, the sequence of operations (or steps) is not limited to the order presented in the figures and/or claims unless specifically indicated otherwise. In the drawings, the thickness of lines, layers, features, components and/or regions may be exaggerated for clarity and broken lines illustrate optional features or operations, unless specified otherwise. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms, “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including” when used in this specification, specify the presence of stated features, regions, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, steps, operations, elements, components, and/or groups thereof. 
     It will be understood that when a feature, such as a layer, region or substrate, is referred to as being “on” another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when an element is referred to as being “directly on” another feature or element, there are no intervening elements present. It will also be understood that, when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other element or intervening elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another element, there are no intervening elements present. Although described or shown with respect to one embodiment, the features so described or shown can apply to other embodiments. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the present application and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Embodiments of the present invention contemplate that repairing tissue (e.g., a torn or damaged tendon of a muscle-tendon unit) using a defined pre-set (pre-load) tension in a reliable and quantifiable manner will improve surgical outcomes and/or reduce re-tearing of soft tissue. In physiology, pre-load tension is important to muscle function. Too little tension or too much tension can cause inefficient and/or inadequate muscle force generation. It is believed that an injured tendon-muscle unit will have an optimal preload repair tension that can improve healing potential post-surgery. It is also believed that the optimum tension may better line up the actin-myosin cross-bridging of the myofibrils. Embodiments of the present invention provide devices that allow a surgeon to quantify the repair tension and possibly manipulate the muscle-tendon unit during repair surgery in a way that optimizes the repair tension. Embodiments of the present invention can also allow a scientist to evaluate the effect of repair tension on muscle-tendon healing/remodeling after tendon injury. 
     The terms “pre-load” and “pre-set” are used interchangeably and refer to a defined or specified tensile force or load (or range thereof) is applied that target tissue should exhibit when attached to local structure to promote healing and/or structural integrity. The target tissue can be soft tissue or hard tissue (e.g., bone). For example, it is contemplated that a rotator cuff undergoing surgical repair should be attached to the humerus head with a pre-load of between about 0.25 lb f  (about 1 N) to about 2 lb f  (about 9 N) when the repaired cuff is attached to the humerus head and the arm is adjacent and substantially parallel to the patient&#39;s torso. However, embodiments of the present invention are not limited by the actual pre-load values but contemplate that a specified pre-load is applied. Actual pre-load values can vary depending on specific parameters of each patient. 
     The target pre-load may differ depending on gender, age and the like of a patient as well as the soft tissue and/or bone undergoing repair. Thus, an anterior cruciate ligament (ACL) may have a different optimal pre-load than a rotator cuff, even in the same patient. 
     Embodiments of the invention are useful for veterinarian and human uses as well as for animal studies. That is, methods and devices provided by embodiments of the invention can be configured for any species of interest, e.g., mammalian including human, simian, mouse, rat, lagomorph, bovine, ovine, caprine, porcine, equine, feline, canine, and the like. 
     Although described primarily for use with torn or otherwise damaged tendons, it is contemplated that the devices and methods will be useful for generating, measuring and maintaining a desired tension force in tendons, ligaments, nerves, tubular vessels (e.g., a ureter or blood vessel), the dermis, bone, flap (tissue) surgery (full thickness, partial thickness and the like) and hard tissue. The devices and methods can be configured to apply, measure and/or maintain tension on a combination of the anatomical structures during a surgical procedure or an animal study. 
     Embodiments of the invention can also or alternatively electronically measure stiffness. Stiffness may be directly or indirectly determined by the tendon tension and tendon extension relationship. 
     Embodiments of the devices can also or alternatively be used to measure a change in length of tissue along with or in response to the applied tensioning (e.g., tendon extension). The measurement can be electronically performed using, for example, a proximity sensor that can communicate with grasped tissue held by the graspers  15  ( FIGS. 1-5 ) to assess a change in length in relationship to a stationary portion of the device  10 . The change in length can be relayed to a display (on-board and/or remote such as those discussed below). 
     The devices can be configured for arthroscopic, robotic and/or conventional open surgery. 
     The term “tissue” refers to soft tissue (e.g., nerves, blood vessels, ligaments, tendons, colon, intestine and the like) and hard tissue (e.g., bone). 
     Referring now to the figures,  FIGS. 1-5  illustrate one embodiment of a surgical device  10 . As shown, the device  10  includes a tissue grasper  15  attached to an elongate member  17  that communicates with a tension measurement device  20 . The tissue grasper  15  can be configured as a clamp-like member with prongs or ends that form substantially an “L” shape as shown. However, other configurations of the tissue grasper  15  can also be used as appropriate. One or both inside faces of the grasper (that contact and hold tissue) can include an anti-slip surface. This surface can be formed as a rough surface finish, include an anti-slide coating or material, and/or have an uneven surface configuration (e.g., peak and valley type surface) to inhibit slippage. The elongate member  17  can be a substantially rigid shaft as shown or may be a cable, such as a Bowden cable. Combinations of shafts and cables may also be used. Where cables are used as the external component, the end of the cable can be attached to the bone using a screw or other fixation device so that the cable does not move with respect to the tendon so that tension can be measured. 
     The tension measurement device  20  can be mechanical and/or electromechanical, including, for example, one or more of the following: a tension transducer, a tension meter (including a digital tension meter), and a load cell. The tension measurement device  20  can reside in a housing  19  that can include graduated indicia  201  of tensile load applied by the tissue grasper  15  to local structure. Alternatively, or additionally, the device  10  can include a display  21  that provides tensile load readout to a user ( FIG. 7 ). 
     As shown, a portion of the shaft  17  is held in a housing  19  with a resilient member  22 , shown as a coil spring  22   s.  The resilient member  22  is able to elastically compress, typically linearly, against an inner wall or surface of an inner housing  24 . The resilient member  22  can be a plug or block of elastomeric material, and/or one of a plurality of spring washers, dome washers, leaf springs, coil springs and the like. As shown in  FIGS. 1-5 , the resilient member  22  is a coil spring  22   s.  The elongate member  17  extends through an axially extending channel formed by the coil  22   s  and is able to slidably extend in and out of the end of the housing  19  facing the graspers  15 . 
       FIG. 3  illustrates that the elongate member (e.g., shaft)  17  can reside above a platform  30  with a slot  30   s.  The housing  19  can slide in the slot  30   s.  The platform  30  includes opposing ends  31 ,  32 . The slot  30   s  extends at least a major length of the platform and ends proximate the second end  31  (the end away from the graspers  15 ). The graspers  15  can extend beyond the bounds of the other end of the platform  32 . As one alternative to this configuration, the platform  30  can be configured to have an outwardly extending projection that engages a slot extending in a lengthwise direction in the housing  19  to allow the graspers  15  to slidably extend and retract relative to the platform  30  (not shown). Other sliding configurations may also be used. 
     As shown in  FIGS. 3-5 , the device  10  can also include a threaded shaft  28  that communicates with a user accessible handle  28   h  such as a thumb wheel or other user handle that allows a user to turn the threaded shaft  28 .  FIGS. 4A and 4B  illustrates the inner housing  24  without the guide  19  (the guide may also be described as an outer housing). The inner housing  24  can slide using downwardly extending projections  24   p  in the slot  30   s  within the guide  19 . In operation, the housing  24  is pulled back (toward the handle  28   h ) by turning the threaded member  28  causing the housing  24  to slide within guide  19  and causing the threaded member  28  to contact and increase compression on resilient member  20 , shown as the coil spring  22   s,  pushing the resilient member  20  (such as the coil spring  22   s ) against the inner wall  24   i  ( FIG. 4 ) of the housing  24  resulting in increased tension on the grasped tendon or other tissue. The tension is identified on a display  21  ( FIG. 7 ) and/or by the graduated indicia  20 I on the guide  19 . 
     In some embodiments, the resilient member  20  comprises a coil spring  22   s  with a “K” stiffness value sufficient to generate a tension of up to about 15 lb f  (about 67 N) in a limited travel/displacement of between about 1-10 inches. 
     During use, a physician or other clinician can slidably extend the tissue grasper  15  to contact and grasp target tissue such as a retracted rotator cuff in the body. When the grasper is closed, the handle  28   h  can be turned to pull the closed graspers  15  outward while applying a tension at a defined load using the tension measurement device  20 . This type of operation may be referred to as a two-stage process. The first stage is extending the graspers  15  to contact the desired tissue. The second step is to measure tension as the tissue is pulled into position during surgery and held at the position with the pre-load tension while the tissue is secured in the position with this pre-load. A clinician can then suture, screw, staple or otherwise secure the target tissue to local structure so that, when secured, the attached target tissue substantially has the desired pre-load tensile force. 
       FIGS. 1-5  illustrate that the device  10  can be limb-mounted using a limb mount member  50  that can be belted or strapped to a patient using strap/belts  52 . The device  10  may also or alternatively be configured to cooperate with a pole or bed (e.g., a pole, table, cart or bed mounted version). That is, the device can include a mount member that attaches to a pole, table, cart or bed instead of the patient limb or in combination with the limb mount (not shown). 
     Where used, the limb mount member  50  may alternatively or additionally be adhesively attached to a patient using straps  52  that have an adhesive surface for releasably attaching to the skin of a patient. Additionally or alternatively the body of the support  50  may have an adhesive on a patient-contacting surface. It is also envisioned that the support  50  may also be modified to be torso mounted. The limb mount member  50  can be concave or contoured to fit the target limb. The limb mount member  50  can be provided in various sizes to accommodate different size patients (e.g., S, M, L, XL). 
     The straps  52  can comprise cloth, fabric, leather or other suitable, typically elastic, material and/or combinations thereof The straps  52  can be configured to inhibit slippage. The straps  52  can be substantially planar or may be tubular (e.g., a rope-like) configuration or other suitable configuration that has a length sufficient to encircle or extend about the torso and/or limb of a subject. The straps  52  may be provided in S, M, L and XL sizes to fit different anatomical sizes of people or may be provided in a universal size. The straps  52  can be attached to clasp or buckle that allows for almost any desired adjustable length. 
     The device  10  can mount to the limb using a joint  70  that allows lateral and longitudinal rotational (pivoting) movement about an axis so that the tensile force can be measured while a patient&#39;s limb is moved through a variety of different angles or orientations (from 0, 15, 30, 45, 60 and 90 degrees) without requiring that the tissue grasper  15  release the tissue. The tension force measurement device  20  may be zeroed at different orientations/degrees. 
     As shown in  FIG. 2A , the device  10  can also optionally be configured to electronically measure an angle of inclination  300  of the arm or other limb associated with axis “A-A” which in  FIG. 2A  is substantially vertical (“0” degrees of inclination) with the arm at the side of the patient. The limb mount  50  can include an angle measurement device  160  (e.g., optical, electrical or electro-mechanical) that communicates with a read-out and/or display on-board or remote from the device  10 . The measurement device  160  can be integral with the body of the limb mount  50  or attached to the extension member  60  or otherwise be provided to be able to measure the different angles of inclination during a procedure. The device  10  may have a User Interface that allows a user to affirmatively indicate when the device should measure tension at a certain angle of orientation (e.g., “measure now”) which can cause the device to electronically measure (and record) both angle and tension. Thus, the tension “T” at different angles of inclination can be electronically measured and correlated.  FIG. 2C  schematically illustrates the device  10  with the arm at two additional angles of inclination “a1, a2”. The different angles and the different measurements can be stored in a circuit/memory for ease of analysis of patient records or animal study data records. 
     As shown in  FIG. 3 , the joint  70  can comprise a gimble ball  70   g.  The term “gimble” refers to a pivoted support that allows the rotation of an object (here the graspers  15 ) in three-dimensions about a single axis. The hollow outer spherical member  70   h  can reside on a lower surface of the upper platform  30  and the matably engaging ball  70   b  can reside on an upper portion of the vertical support  60 . In other embodiments, the ball and spherical members are reversed, e.g., the ball  60   b  is attached to the upper platform  30  and the spherical hollow member  70   h  is attached to the vertical member  60 . The gimble  70   g  can be releasably locked into position. However, other joint configurations may be used such as, for example, a spring, pin, linkages, cams, gears or other pivoting or rotational configurations. 
       FIGS. 1-5  also illustrate that the device  10  can include a vertically extending adjustable member  60  that can attach the limb-mount member  50  to the platform  30  via the joint  70 . The vertical adjustment member  60  can include a slot that attaches to locking members  54  on the limb-mount member  50 . 
       FIG. 6  illustrates that the device  10 ′ can be hand-supported during use and does not require the limb mount described above. During use, one physician (or a physician assistant, nurse or other clinician) can hold the device in position at the desired pre-load tension during the repair while another secures the target tissue to local structure(s). The device  10 ′ may also be configured to cooperate with a pole, cart, table or bed (e.g., a pole or bed mounted version) as well (not shown). 
       FIG. 6  also illustrates that a user can measure applied tension “T” by monitoring the indica  20 I (e.g., graduated scale) on the tension measurement device  20 . No threaded member  28  or handle  28   h  is required. The body of the housing  19  can slide rearward compressing a resilient member  20  and the position of an indicator on the shaft or other elongate member  17  can align with indicia  20 I to define the tensile load applied by the graspers  15 . This configuration can also be used with a limb mount  50  as described above or with a pole or bed mount.  FIG. 7  illustrates a device  10 ″ which includes a tension measurement device  20 , such as a transducer  20 T, in communication with the graspers  15  via elongate member  17  (e.g., shaft or cable and the like). The device  10 ″ can include an on-board display in electrical communication with the transducer  20 T which can visually show the measured tension. Again, the device  10 ″ may include a limb mount  50  as discussed above or can be used with a pole or bed mount. 
       FIGS. 8A and 8B  illustrate an exemplary rotator cuff repair. As shown in  FIG. 8A , the device  10 ,  10 ′,  10 ″ is used to apply a pre-load tension “T” onto the tendon while a surgeon attaches the tendon to the humerus head. When the tendon has been attached to the humerus head as shown in  FIG. 8B , the grasper  15  can release the tendon and the cuff has the desired pre-load “T”. 
       FIG. 9  illustrates another embodiment of the device  10 ′″. As shown, the device  10 ′″ includes the graspers  15  and an elongate member  17  that is in communication with a tension measurement device  20 . The tension measurement device  20  can be any suitable type device such as those described above. The device  10 ′″ can include a circuit  120  with an on-board digital signal microprocessor or ASIC (Application Specific Integrated Circuit)  120  that includes or communicates with a computer tension guide module  220  or is otherwise programmed to provide at least one defined pre-load tension, typically one or more defined pre-load tensions for one or a plurality of different target tissues (potentially correlated to gender and/or age). The device  10 ′″ can optionally include an on-board display  21 . The device  10 ′″ can also be configured to wirelessly communicate with a (larger) remote device  228  with a display  221  such as a clinician workstation or personal digital assistant and the like. The device  10 ′″ can be configured to measure tension load in a plurality of different positions (e.g., between 0-90 degrees). 
     As shown in  FIGS. 10A-10B , the device  10 ′″ can be configured to provide a UI (user interface)  229  that allows a user to select the desired tension for a target tissue. The UI  229  can be associated with the remote display  221  and/or the on-board display  21 . The UI  229  can be a touch screen, keypad or other entry. That is, the UI  229  can be integrated into the device  10 ′″ or the device  10 ′″ can cooperate with the remote device  228  that includes or communicates with a UI  229 . If the latter, the input and/or output can be wirelessly transmitted between the device  10 ′″ and the remote device  228 . 
       FIG. 10A  illustrates a UI  229  with a pull-down menu of different target tissues  230  (or the same target tissue but an age or gender input as well). The selection of this parameter  230  can automatically or electronically cause the device  10 ′″ to recognize the target pre-load tension  231  for the patient and select that tension for monitoring as the device reaches this tension “T”. An alert (audio and/or visual) can be generated by the device  10 ′″ when the target tension has been reached and/or if the pre-load tension is exceeded. 
       FIG. 10B  illustrates the UI  229  can allow a user to enter a target pre-load tension directly  232  and “set” this value for use during the procedure. 
     As shown in  FIG. 10C , in some embodiments, the on-board and/or remote display  21 ,  221  can have a UI  229  that displays the measured loads as a graph as shown in  FIG. 10C , illustrating Tension versus angle, the angle referring to the angle or orientation of the limb or digit (e.g., finger, thumb, toe). The measured loads can be graphically displayed adjacent target loads. 
     The device  10 ′″ can include a speaker  225  that can be configured to automatically generate an audible alert such as a tone or a pre-recorded voice/verbal instruction, word(s) or message. The device  10 ′″ may also generate a visual alert (e.g., a flashing light or a “red” light and the like) if a measured tension load exceeds or is under a target tensile load (in one or more orientations) and/or a visual or audible alert if the tension is within the desired range (e.g., a constant light rather than a flashing light, a green light, a different audio or verbal message from that generated when the load is over or under the desired load and the like). The alert can be automatically transmitted or output while the grasper  15  is in the body and engaging tissue. The grasper  15  can be configured to automatically activate the tension measurement device when closed. The grasper  15  can include a proximity sensor or may be configured to define a closed or open circuit when closed to electronically automatically activate the tension measurement device  20 . The device can include an on-board power source. The tension measurement device  20  can be in communication with the power source. The power source can be a small battery, such as a pancake type battery or other small battery. The device  10 ′″ may also have an on-board digital camera for generating images of the grasper  15  and/or target tissue during the procedure. 
     The circuit  120  can include a digital signal processor and/or an Application Specific Integrated Circuit (ASIC) (e.g., ASIC and/or processor with software) that includes or executes part or all of the computer readable program code for generating the tension measurement, readout and/or alert. The circuit  120  or module  220  can include a data processing system which may, for example, be incorporated or integrated into the processor. The processor can communicate with or include electronic memory. The processor can be any commercially available or custom microprocessor. The memory is representative of the overall hierarchy of memory devices containing the software and data used to implement the functionality of the data processing system. The memory can include, but is not limited to, the following types of devices: cache, ROM, PROM, EPROM, EEPROM, flash memory, SRAM, and DRAM. 
     The processor or memory may include several categories of software and data used in the data processing system: the operating system; the application programs; the input/output (I/O) device drivers; and tension data. 
     As will be appreciated by those of skill in the art, the operating systems may be any operating system suitable for use with a data processing system, such as OS/2, AIX, or zOS from International Business Machines Corporation, Armonk, N.Y., Windows CE, Windows NT, Windows95, Windows98, Windows2000, WindowsXP, Windows Visa, Windows7, Windows CE or other Windows versions from Microsoft Corporation, Redmond, Wash., Palm OS, Symbian OS, Cisco IOS, VxWorks, Unix or Linux, Mac OS from Apple Computer, LabView, or proprietary operating systems. 
     The I/O device drivers typically include software routines accessed through the operating system by the application programs to communicate with devices such as I/O data port(s), data storage and certain memory components. The application programs are illustrative of the programs that implement the various features of the data processing system and can include at least one application, which supports operations according to embodiments of the present invention. The data represents the static and dynamic data used by the application programs, the operating system, the I/O device driver and the like. 
     The device  10 ′″ can wirelessly communicate with a workstation and/or other remote computer device  228 . The remote device  228  can include a display  221  can communicate with a computer which includes a portal and an Application that allows the tension data to be graphically displayed for a patient record or other data record. The device  10 ′″ can communicate with the remote device  228  via a computer network including an intranet or the internet with the appropriate use of firewalls for patient privacy and compliance with HIPPA (Health Insurance Portability and Accountability Act) or other regulatory rule or authority. 
     The foregoing is illustrative of the present invention and is not to be construed as limiting thereof Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. In the claims, means-plus-function clauses, if used, are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.