Abstract:
An adjustable vascular compression device assists in achieving partial or full occlusion of a blood vessel when applied to a patient&#39;s limb, for example, during or following a medical procedure. Pads on the device apply preferential compression to portions of the circumference of the limb so as to enable blood flow through adjacent blood vessels during the compression period. Further, rapid fastening, tightening, loosening and release is enabled by a single mechanism, and gradual adjustments to the tightness may be made without releasing said mechanism.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Patent Application Ser. No. 61/198,956 filed Nov. 12, 2008, the contents of which are incorporated herein in their entirety by this reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention generally relates to compression devices for occluding blood flow through a blood vessel. More particularly, the invention relates to an apparatus for reducing or stopping blood flow in a blood vessel by means of adjustably applying compression to the body surface overlying said blood vessel. 
       BACKGROUND OF THE INVENTION 
       [0003]    A number of devices have been utilized to externally compress blood vessels in various parts of the body for the purpose of reducing or stopping the flow of blood through said vessels. A tourniquet is a simple device used around a limb which, when tightened, reduces or stops arterial blood flow to the distal portions of the limb and thereby minimizes hemorrhaging from wounds or punctures in the vessels. For medical procedures, tourniquet-type devices have been specifically designed to prevent bleeding through a cannulation or needle puncture in a vessel in a patient&#39;s forearm. U.S. Pat. No. 5,269,803 by Geary et al. discloses a strap that encircles the forearm with a pressure pad that applies compression over the vessel to prevent bleeding through the puncture. Other devices that include a strap to prevent bleeding through a puncture site include: U.S. Pat. No. 4,182,338 to Stanulis; U.S. Pat. No. 4,005,709 by Laerdal; U.S. Pat. No. 3,954,109 by Patel; and U.S. Pat. No. 3,586,001 by Sanderson. 
         [0004]    Several devices have improved upon the basic tourniquet by applying pressure to only selected points instead of around the entire circumference of the limb, for example: U.S. Pat. No. 6,647,986 by Korotko et al; U.S. Pat. No. 5,728,120 by Shani et al; U.S. Pat. No. 5,601,597 by Arrowood et al; U.S. Pat. No. 5,569,297 by Makower et al; U.S. Pat. No. 5,295,996 by Blair; U.S. Pat. No. 5,234,459 by Lee; U.S. Pat. No. 4,760,846 by Kelly et al; U.S. Pat. No. 4,557,262 by Snow; U.S. Pat. No. 3,570,496 by Sachs; U.S. Pat. No. 2,271,927 by Saighman; and U.S. Pat. No. 1,473,041 by Henderson. Each of these devices includes a strap for encircling a patient&#39;s limb, and pressure pads or similar devices to apply compression to stop the blood flow through the target vessels in the limb. A device called the TR Band marketed by Terumo utilizes a wrist-encircling tourniquet-type strap that applies compression by means of an inflatable bladder. 
         [0005]    Other devices are known to the inventors, which, although they do not take the form of a tourniquet or derivative device, help achieve hemostasis in blood vessels. Examples include: U.S. Pat. No. 5,304,186 by Semler, et al; U.S. Pat. No. 4,742,825 by Freund et al; U.S. Pat. No. 4,572,182 by Royse; U.S. Pat. No. 4,233,980 by McRae et al; U.S. Pat. No. 3,779,249 by Semler. These disclose mechanical and pneumatic means of applying compression over a blood vessel for the purpose of allowing a clot to form, thereby enabling hemostasis and corollary cessation of bleeding. Features noted in this art are: i) the use of clamping or inflatable bladder mechanisms to apply compression to the body surface overlying a target blood vessel and not all vessels in or leading to the extremity, and ii) the incorporation of features to gradually reduce compression and permit direct visual observation of a surface wound or puncture site leading to the target vessel close to the point of compression. 
         [0006]    Additional patents disclose straps that are used in combination with pressure pads for therapeutic purposes other than occluding the flow of blood: U.S. Pat. No. 5,372,575 by Sebastian; U.S. Pat. No. 5,312,350 by Jacobs; U.S. Pat. No. 5,135,473 by Epler et al.; U.S. Pat. No. 5,078,728 by Giarratano; U.S. Pat. No. 4,590,939 by Sakowski; U.S. Pat. No. 4,479,495 by Isaacson; U.S. Pat. No. 4,323,232 by Terpening; U.S. Pat. No. 4,308,861 by Kelly; U.S. Pat. No. 4,243,028 by Puyana; and U.S. Pat. No. 519,894 by Schutz et al. 
         [0007]    The prior art teaches that compression applied externally, i.e. on the body surface and over a target blood vessel slows the blood flow such that a clot can form so that normal hemostasis may occur. The prior art further teaches the value of: i) visual and physical access to the puncture or wound site on the body surface, and ii) preferential compression over a target vessel, so that arterial flow to or venous return from an extremity, for example a hand, are important attributes of a device having the purpose of achieving hemostasis following cannulation. 
         [0008]    One requirement, well-known to clinical practitioners, which arises following medical procedures involving an arterial puncture, for example, radial artery catheterization, is the necessity to gradually release compression over the vessel to gradually increase blood flow while not disturbing the clot formed during the hemostasis process. Devices used for hemostasis, for example, as described by Semler, provide a means of gradually reducing compression. While there are many references that disclose the broad concept of using a strap with a pressure pad to stop the flow of blood through an arterial puncture wound located on the arm or wrist, none of these devices provides a convenient, user-controlled, easily-adjustable means of: i) rapidly applying compression to a blood vessel while the cannula is removed, and ii) adjusting the amount of compression being applied to the point of compression in fine increments without releasing the fastening mechanism of the apparatus, and iii) quickly releasing compression and removing the device from the patient, and iv) integrating the adjustment and fastening means to enhance ease of use, and v) enabling distal blood flow through adjacent blood vessels, for example, distal blood flow through the ulnar artery and venous return from the hand. Therefore, a need exists for an adjustable vascular compression device. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention generally relates to devices for use following cannulation procedures performed on blood vessels in a limb of a patient, for example, during or after radial artery catheterization procedures, or during or after a hemodialysis session, or during or after withdrawal of a cannula from a vein or artery in a patient&#39;s arm. More particularly, the present invention describes an adjustable vascular compression device which applies compression on a patient&#39;s body surface overlying a blood vessel thereby constricting said vessel, for the purpose of reducing or stopping blood flow at that point of compression, for example, proximal to or over a radial artery puncture site, to permit hemostasis to occur at the site by reducing or eliminating blood flow at and distal to the point of compression. Alternatively the compression may be applied directly over the puncture site or at a point distal to the puncture site. Thus, the present invention provides utility in assisting with hemostasis following medical cannulation procedures on the limbs of a patient, for example, in: radial artery catheterization procedures for interventional cardiology, diagnostic cardiology and radiology; surgery; other cardiac procedures including electrophysiology; kidney dialysis; and, withdrawal of catheters, wires or other cannulae from a patient&#39;s blood vessels for other medical applications. 
         [0010]    The compression device of the present invention has, features that permit sufficient adjustable compression to be applied to a target blood vessel in a patient&#39;s limb, for example, a radial artery, while, at the discretion of the user deploying the device on a patient, also maintaining blood flow through the target vessel or other vessels in the limb. For example, the device may be used to partially or fully occlude blood flow through a radial artery, with adjustments by the user to gradually increase flow as hemostasis occurs, while simultaneously permitting distal arterial blood flow through the ulnar artery and venous return from the hand. In addition, the device further provides: i) a securement means for quickly fastening the device around the patient&#39;s wrist and providing compression over the artery, ii) an adjustment means for the user to adjust the compression in small increments and iii) a release means further enabling rapid release of compression and removal from the wrist. More particularly, the device may be quickly secured and tightened as a cannula is removed to provide compression over the cannulated artery, and subsequently such compression may be tightened or loosened in small continuous increments at the user&#39;s discretion without releasing the primary means by which the device is secured. 
         [0011]    Preferably, the apparatus is formed of materials that may be assembled, packaged and pre-sterilized for single-use applications. Alternatively, the device may be provided in partially assembled or non-sterilized form. 
         [0012]    In view of the above, an object of the adjustable vascular compression device of the present invention is to provide an apparatus that provides external compression, i.e. onto a body surface, which in turn compresses an underlying target blood vessel for the purpose of slowing or stopping blood flow to assist in achieving hemostasis of a puncture or wound. 
         [0013]    Another object of the present invention is to enable the device to be rapidly applied and fastened to the patient and, following use, rapidly removed from the patient. 
         [0014]    Another object of the present invention is to enable a user operating the device to make fine adjustments in the amount of external compression applied to the vessel following device deployment without releasing the fastening mechanism, one purpose of which is to enable adjustment to permit user-controlled “patency” of the vessel (i.e. the extent of flow therethrough) during compression. 
         [0015]    Another object of the present invention is to provide a user with both visual and physical access to the area of the puncture site while the compression device is applied to the patient. 
         [0016]    Another more particular object of the present invention is to provide external compression of a target blood vessel, specifically an artery or vein in the arm or wrist, directly over or near to a puncture site on the body surface, which leads to an arteriotomy or venotomy, for the purpose of stopping or slowing distal blood flow. 
         [0017]    Another more particular object of the present invention is to provide user-adjustable external compression of a radial artery, following a catheterization or other medical cannulation procedure, such that the vessel under compression retains a degree of patency. 
         [0018]    Another more particular object of the present invention is to provide external compression of a target blood vessel while permitting generally unimpeded flow of blood in other adjacent blood vessels, for example, limiting or stopping blood flow in the radial artery while permitting distal flow through the ulnar artery to the hand and venous return from the hand. 
         [0019]    The device of the present invention achieves these and other objects through its inclusion of elements that generally include a strap having threads at one end and a housing at the other end, a compression pad, and a threaded element. The device may further include an ulnar pad. Though these elements are described and shown as separate elements assembled into a single device it will be understood that they may alternatively be composed as an assembly having fewer or more separate elements, for example, one or both of the radial and ulnar pads may be formed with the strap as a single unitary element. 
         [0020]    A housing located at one end of the strap holds the threaded element, more particularly, a fully rotatable adjustment screw, within it and further provides sufficient flexion, through a hinge means at one end, to enable quick release of the strap when the hinge means is flexed. Pulling on the screw contained within the housing perpendicularly to its longitudinal axis would then cause it to act as a lever, and is a means of effecting such flexion of the hinge means. As an alternative to using a fully rotatable adjustment screw, a fully or partially threaded bolt which is non-rotatable or which has a maximum rotation of less than 360 degrees, more particularly less than 240 degrees, may be included as the threaded element. A threaded element may also be integrally formed as a non-separable, for example, molded in, part of the strap. 
         [0021]    The end of the strap opposite the end on which the housing is located is passed through the housing so that the strap encircles the arm or wrist of the patient. Threads on the strap which engage the threaded element provide a securement means for fastening the device around the arm or wrist of the patient. The fit of the threaded element within the housing and the engagement of its threads with the threads of the strap enables the strap to be quickly tightened and retained under tension around the arm or wrist, and permits easy movement of the strap through the housing when the strap is being pulled through. When an adjustment screw is used, by rotating it, tension is gradually increased or decreased as the threads on the screw engage the threads on the strap to change the circumference of the strap around the arm or wrist, thus enabling the gradual fine adjustments without releasing the fastening mechanism. Thus, in combination with the housing through which the strap is passed, the adjustment screw and the threads on the strap further provide an adjustment means. Pulling the screw away from the strap and perpendicularly to its longitudinal axis would then cause it to act as a lever to flex open the hinge means, thereby decoupling the threads on the strap from the threads on the threaded element, providing a release means. The apparatus thus enables both rapid securement and release, and fine adjustments to tension without releasing the means of securement. 
         [0022]    In the event that a fully or partially threaded bolt is employed, said bolt may be fit in place of the rotatable adjustment screw into the housing, to simply engage with the threads on the strap to provide the securement means, without the ability to make fine tension adjustments. The threads of the bolt are present on at least the side facing the threads on the strap when the strap is inserted into the housing. A tab, handle or other grasping means on either an exposed portion of the threaded element or on the housing provides a lever to enable the user to deflect the housing in its vertical axis, to provide the release means, to permit quick release of the strap. 
         [0023]    The compression pad provides preferential compression directly over the radial artery. The ulnar pad provides a cushion against the ulnar side of the forearm. The ulnar and compression pads also position the strap away from the body surface of the forearm to enable blood flow through underlying blood vessels. One or both of the pads may be integrally formed as non-separable, for example, molded-in, parts of the strap, or may be formed as separate parts to be attached to the strap. The pads may be formed in a variety of shapes, each suitable for a specific application, for example, a pad having a notch or holding means for an absorbent or other material, for example having hemostatic properties, may be employed for hemostasis of hemodialysis needle sites while a pad having an elongate shape may be employed for a post-catheterization hemostasis of a radial artery. Such pads can further include additional materials attached to their surfaces that make contact with a patient&#39;s body surface for the purpose of providing cushioning, for comfort, or for assisting with the compression of the target blood vessel, or for otherwise assisting with the medication or hemostasis of the puncture site in the blood vessel. A notch or groove may be further included on the bottom of such pad to guide placement of the pad over the cannula inserted into the puncture site on the skin surface, to provide accurate placement of compression. 
         [0024]    All or part of the apparatus, including the compression pad, may also be composed of a material having anti-microbial properties sufficient to prevent growth of microbes or to kill microbes with which it comes into contact, for example on the skin of a patient on whom the apparatus is deployed. Alternatively, the exterior surfaces of the compression pad or other components of the apparatus may be treated with a process or material having anti-microbial properties. Examples of these processes and materials, which are well-known to those skilled in the art, can include: i) the deposition of silver or organic or inorganic particles onto the surfaces of the components of the apparatus by means of vapor deposition or liquid immersion; or ii) including silver or organic or inorganic particles mixed into the materials from which the components are formed. 
         [0025]    It will be understood by those skilled in the art that, although the following drawings and Detailed Description disclose further aspects and advantages of the apparatus and describes preferred embodiments, the present invention is not intended to be limited only to these preferred embodiments. It will be apparent that other changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is a top isometric view of an adjustable vascular compression device. 
           [0027]      FIG. 2  is a bottom isometric view of the device. 
           [0028]      FIG. 3A  is a top isometric view of a strap element of the device. 
           [0029]      FIG. 3B  is an end view of a strap thread element of the strap element, taken along lines  3 B- 3 B of  FIG. 3A . 
           [0030]      FIG. 4  is a bottom isometric view of the strap element. 
           [0031]      FIG. 5  is a side elevation of a housing of the strap element. 
           [0032]      FIG. 6  is a side isometric view of a screw element of the device. 
           [0033]      FIG. 7A  is a side isometric view of a compression pad element of the device. 
           [0034]      FIG. 7B  is a bottom view of the compression pad element. 
           [0035]      FIG. 8A  is a side isometric view of an alternative embodiment of the compression pad element. 
           [0036]      FIG. 8B  is a side elevation of an alternative embodiment of the compression pad element. 
           [0037]      FIG. 9  is a cross-sectional view of a wrist, with the apparatus attached. 
           [0038]      FIG. 10A  is a fragmentary plan view of the apparatus attached to a wrist, with parts removed for clarity. 
           [0039]      FIG. 10B  is a fragmentary plan view of an alternative embodiment of the apparatus attached to a wrist, with parts removed for clarity. 
           [0040]      FIG. 11A  is a fragmentary, cross-sectional elevation, with parts removed, of screw threads engaging the strap threads on a notch of the strap threads inside the spring guide of housing of the strap element. 
           [0041]      FIG. 11B  is a fragmentary, cross-sectional elevation, with parts removed, of screw threads engaging the strap threads off of the notch of the strap threads inside the spring guide of housing of the strap element. 
           [0042]      FIG. 12A  is a side view of a bolt. 
           [0043]      FIG. 12B  is a bottom view of the bolt taken along lines  12 B- 12 B of  FIG. 12A . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0044]    An adjustable vascular compression device  10 , for use in assisting with post-procedure radial artery hemostasis following catheterization or other cannulation, is shown in the drawings and Detailed Description included herein as a preferred embodiment of the present invention. Although parts are described as discrete components and features are described with specific structures, it will be understood by those skilled in the art that alternative means of construction to achieve the same purpose may be employed without deviating from the present invention. 
         [0045]    As illustrated,  FIGS. 1 and 2  show an adjustable vascular compression device  10 , which includes a strap  80  to which a threaded element, more particularly a compression pad  20  and an adjustment screw  60  are attached. (Those of skill in the art will appreciate that a bolt or other fixation device, e.g. a bolt  70 , may be used as an alternative to an adjustment screw  60 , as indicated in  FIGS. 12A and 12B . Other suitable alternatives for a threaded element are contemplated as being within the spirit and scope of the invention.) Strap  80  is configured to be slidably received through openings provided in a compression pad to be described below, and strap  80  is dimensioned to have a width W of between approximately 0.2 centimeters and approximately 5.0 centimeters, more particularly between approximately 0.5 and approximately 2.5 centimeters to correspond nominally and substantially with the dimensions of such openings, as described and illustrated herein. 
         [0046]      FIG. 3A  further shows that the strap  80  includes at one end an angled strap tip  85  and at the opposite end a housing  82 , one side of which comprises the ulnar pad  40 . The housing  82  further includes a spring guide  87  (alternatively referred to herein as a release lever), a spring hinge  88 , a cutout  94  and a strap-tip exit opening  83 . Strap threads  81  are shown on a top surface  86  of strap  80 . The width W (refer briefly to  FIG. 7A ) of the strap  80  may be between 0.2 centimeters and 5 centimeters, more particularly between 0.5 and 2 centimeters. The height H (refer briefly to  FIG. 7A ) of the strap  80  may be between 0.2 millimeters and 10 millimeters, more particularly between 0.5 millimeters and 5 millimeters. Fingertip tabs  95  are shown on either side of the housing  82 . 
         [0047]    Tabs  95  will be appreciated by those of skill in the art to leverage the release of spring hinge  88 . The tabs can be used singly or collectively with one or more fingers of either user hand to oppose the thumb&#39;s arcuate or pivotal movement of spring guide  87  outwardly away from the body of housing  82 , thereby to facilitate release strap  80  from housing  82 . Alternative configurations of one or more tabs or wings on housing  82  are contemplated as being within the spirit and scope of the invention. 
         [0048]      FIG. 3B  shows a strap thread  81  in end view taken along lines  3 B- 3 B of  FIG. 3A . A bottom surface  89  of the strap is shown as is a concave notch  93  in the center of an upper region of the thread  81  opposite the bottom surface  89 . 
         [0049]      FIG. 4  further shows a strap-tip insertion opening  91  and screw retention hole  90  located near the spring hinge  88  on the housing  82 . Insertion opening  91  will be understood to accept angled end  85  of strap  80  to be inserted thereinto as the strap is placed around a wrist. 
         [0050]      FIG. 5  shows additional elements of the housing  82 , including the ulnar pad  40 , the tail  41  of the ulnar pad, convex surfaces  43  of the ulnar pad and its height  44 , which creates a wrist-standoff space  105  shown in  FIG. 9 .  FIG. 5  further shows the exit opening  83 , the insertion opening  91 , a cutout  94  that creates the spring hinge  88 , and an arc or arcuate axis  92  that represents the direction of movement of the spring guide  87  permitted by the spring hinge  88 . 
         [0051]      FIG. 6  shows the elements of the adjustment screw  60  including a generally frusto-conical or tapered shaft  62 , threads  63  having a top end  63   a  and bottom end  63   b , a stop ring  64  and retention knob  65 . The screw threads  63  have outside helical edges  66   a  and corresponding inside helical edges  66   b , the outside and inside helical edges being referred to herein as a double helix. The stop ring  64  and retention knob  65  serve to retain the screw  60  in the screw insertion hole  90  and spring guide  87 . The screw  60 , when retained in place in the spring guide  87  and with its screw threads  63  meshing with the strap threads  81 , serves as both a fastening and compression adjustment means for the device  10 . 
         [0052]      FIGS. 7A and 7B  show side and bottom aspects of the compression pad  20 , designed for placement directly over a puncture site  106  as shown in  FIG. 10A . Loops  22  create strap openings  23  through which strap-tip  85  and an adjustable length of the strap  80  passes. In accordance with one embodiment of the invention, the strap openings are configured to fit slidably around the strap, and are dimensioned to have a width W of between approximately 0.2 centimeters and approximately 5.0 centimeters, more particularly between approximately 0.5 and approximately 2.5 centimeters. Also in accordance with one embodiment of the invention, the strap openings have a height H of between approximately 0.2 millimeters and approximately 10 millimeters, more particularly between approximately 0.5 millimeters and 5 millimeters. Those of skill in the art will appreciate that these nominal measurements H and W of the openings are applicable also to the respective height and width of strap  82  which is received therethrough. Alternative opening widths and heights are contemplated as being within the spirit and scope of the invention. 
         [0053]    The body of the compression pad  20  comprise end sidewalls  26 , lateral sidewalls  25  and a compression surface  24  on the bottom. A notch  21  is located on the compression surface  24 , which may be located at one end or on each end of the pad  20 . The notch  21  serves to help the user position the pad  20  during deployment onto a patient and further provides a path for a cannula when it is withdrawn from the blood vessel. The strap openings  23  are of a size such that the strap loops  22  fit over the strap  80 , such fit enabling slidable movement of the compression pad  20  along the length of the strap  80  and adjustment for such variables as wrist circumference, desired vascular compression, and patient comfort. 
         [0054]    In accordance with one embodiment of the invention, the compression pad  20  is dimensioned as follows: The footprint of the pad has an area of between 1.0 and 5.0 square centimeters, or more particularly a length of approximately 2.95 centimeters and a width of approximately 0.9 centimeters for a nominal 2.66 cm 2  patient skin contact surface area. The nominal height of the pad  20  that determines the nominal height of space  105  is approximately 0.5 centimeters, although it will be appreciated that any suitable height between approximately 0.25 to 5.0 centimeters is contemplated as being within the spirit and scope of the invention. All dimensions are approximate due to rounded edges and corners. Moreover, those of skill in the art will appreciate that alternative dimensions are contemplated as being within the spirit and scope of the invention. Those of skill in the art also will appreciate that alternative configurations, shapes, contours, and radii of curvature are contemplated as being within the spirit and scope of the invention. 
         [0055]    Those of skill in the art will appreciate that compression surface  24  can be rigid or yieldable, i.e. somewhat compressible or malleable. For example, it can be formed to have a lower, skin contacting surface that ‘gives’ slightly when pressed against a person&#39;s skin, or it can be covered by a material that is so characterized, thereby further increasing the comfort to the patient during use of the invented apparatus. Such compression surface  24  may be formed as a unitary part of the compression pad  20 , or alternatively as a separate element, e.g. a material expanse, that is attached to the compression pad  20 . 
         [0056]      FIG. 8A  shows an alternative embodiment of a compression pad  20 A, which includes elements similar to the preferred embodiment of the compression pad  20 , but positioned in a different configuration for use proximal to a puncture site  106  shown in  FIG. 10B . Those of skill in the art will appreciate that the more angular facial (faceted) features of this embodiment of compression pad  20 A provides a larger and deeper notch  21 A providing a larger and deeper cannular approach, e.g. a slightly larger target zone, for visual and physical access to the radial artery or other blood vessel. This alternative embodiment of the pad might be used for example for hemodialysis, but not for radial artery cannula removal. With the radial artery, given its proximity to the palmar arch which is an artery that connects the radial artery and the ulnar artery, pad placement proximal to the access site may not work since the ulnar artery blood flow may cause bleeding from the site. With a shunt, pad placement proximal to the site may work since the ulnar blood flow does not necessarily create the ‘backflow’ to cause bleeding from the puncture site.  FIG. 8A  shows a pad designed for proximal placement, with the notch  21 A providing both visual and fingertip access to the puncture site. 
         [0057]    In contrast, with the compression pad of  FIG. 7A , the rounded feature avoids sharp edges which could create patient discomfort when the device is applied under compression. It also provides more skin surface coverage as compression increases since the pad will “sink” into the tissue, since muscle and fat tissue is generally compliant. The notch  21  enables better positioning of the pad along the longitudinal axis of the target blood vessel, i.e. the radial artery, since the cannula protruding from the puncture site will fit over the notch  21 , thus guiding the user to properly place the pad directly over the puncture site and not proximal or distal, or off to one side. The slightly convex shape of the bottom surface  24  also helps make deployment more comfortable for the patient by avoiding hard edges of the pad. It further focuses compression at the center point of the surface  24  as well as providing a long surface for compressing (albeit at a slightly lesser amount) the target vessel proximal and distal to the arteriotomy. This provides some small placement error margin, which may be needed since the arteriotomy, though close to the puncture site, is not directly under it. 
         [0058]      FIG. 8B  shows an alternative embodiment of a compression pad  20 B which includes elements similar to the preferred embodiment of the compression pad  20 , for use over a puncture site  106  as shown in  FIG. 10A . Included are loops  22 B creating strap openings  23 B, lateral sidewalls  25 B, end sidewalls  26 B, a compression surface  24 B, and further including a concavity  27  located in the compression surface  24 B for enabling physical and visual access to the puncture site  106 . Alternatively, the concavity  27  can be used to attach a separate component to the compression pad  20 B. For example, a piece of medical gauze, a sponge, a pad, a hemostatic material, or another object can be removably attached in concavity  27  to assist in compressing the puncture site  106 . The concavity  27  can assume alternative forms including a trough-like concavity extending from side to side, or a pocket or depression generally within a central lower surface of the compression pad  20 B, having sidewalls all around (as suggested by the horizontal dashed line along the bottom surface of the pad in  FIG. 8B ). The concavity can be of a regular shape, e.g. a trough of generally semicircular or parabolic cross section as shown or a pocket of generally semispherical or other regular geometric cross section. Alternatively, the concavity can be of an irregular shape to accommodate any object of irregular shape therein. 
         [0059]      FIG. 9  shows application of the device  10  onto a wrist  100  for the purpose of occluding a blood vessel  102 , in this case a radial artery, while keeping the ulnar artery  101  and veins  103  “patent” (relatively open to blood flow), by means of the standoff space  105  created between the strap  80  and the surface of the wrist  104 . 
         [0060]      FIG. 10A  shows the preferred embodiment of the compression pad  20  in position directly over the blood vessel  102  and puncture site  106 , with its compression surface  24  overlying the blood vessel  102  in its longitudinal axis. 
         [0061]      FIG. 10B  shows an alternative embodiment of the compression pad  20 A in a position proximal to the puncture site  106  and over blood vessel  102 . The compression surface  24 A lies over the blood vessel  102  but exposes the puncture site  106  by means of the notch  21 A. 
         [0062]      FIGS. 11A and 11B  show the screw  60  in place in the spring guide  87  of the housing  82 , the strap threads  81  engaging with the screw threads  63 .  FIG. 11A  shows the outside edges  66   a  of the screw threads in full contact with both the interior surface of the spring guide  87  and the portions of the top surface  86  of the strap  80  located between the threads  81 . In this position, the strap  80  is retained in place against a pulling force of a user attempting to unfasten the device, since the screw threads  63  block movement of the strap threads  81 .  FIG. 11B  shows the screw  60  and its screw threads  66  elevated onto the concave notch  93  of the strap threads  81  when the strap-tip  85  of strap  80  is pulled to fasten the device. The movement of the strap  80  in the fastening direction causes the screw threads  63  to move to engage the concave notch  93  and travel up on top of them, this movement of the screw  60  in the vertical axis  92  being permitted by the opening of the flexible spring hinge  88  (not shown in these figures) as it is forced open by the vertical travel of the screw  60 . Thus when being fastened, the strap  80  is able to move in the fastening direction, but not in the unfastening direction due to the meshing of the screw threads  63  and strap threads  81 . As the strap  80  continues to move in the fastening direction the concave notches  93  on the strap threads  81  move out from underneath the screw threads  63 , enabling the screw  60  to move downwards in the arcuate axis  92 , this movement being caused by the closing of the spring hinge  88 . 
         [0063]      FIGS. 12A and 12B  show a different kind of threaded element, as an alternative means of providing securement of the device  10 , without the ability to make significant fine adjustments in the amount of compression. A bolt  70  is shown, to be used in the housing  82  of the strap  80  instead of an adjustment screw  60 . The advantage of this embodiment is enhanced simplicity of use. The bolt  70  includes a bolt thread  67 , a non-threaded spine  68 , and, similar to the adjustment screw  60 , bolt  70  further includes a shaft  62 , stop ring  64 , and a retention knob  65 . Located at the wide end of the spine is a quick-release tab  69 . Those of skill in the art will appreciate that the bolt described and illustrated herein represents only one of many alternative embodiments contemplated as being within the spirit and scope of the invention. 
         [0064]    A preferred embodiment of the device  10  includes a strap  80 , a screw  60 , and a compression pad  20 . The strap  80  includes a housing  82 , a tip  85 , a top surface  86 , and a bottom surface  89 . The housing  82  includes an ulnar pad  40  that faces towards the ulnar surface of the wrist  100  when device  10  is applied to a patient. The housing  82  further includes a strap-tip exit opening  83 , a spring guide  87 , a spring hinge  88 , a screw retention hole  90 , a strap-tip insertion opening  91  and a cutout  94 . The top surface  86  has strap threads  81  formed onto it. Each of the strap threads  81  has a concave notch  93  at its center. The tip  85  may optionally include a downward deflection as part of its structure to more easily enable the strap  80  to be pulled through the housing  82  and exit opening  83  without being impeded by aspects of the screw  60 , for example the knob  61 . The strap  80  can be formed of a material that has the properties of flexibility and shear strength, since flexibility is needed for it to be twisted, flexed or deflected so as to fit around a wrist  100 , and since shear strength is needed to enable it to withstand the tension incurred during deployment. Examples of such a material can include, but are not limited to, a polypropylene or other plastic, or a nylon or a woven synthetic or natural material. The spring hinge  88 , when the strap  80  is formed of a material generally of the types herein described, thus functions as a live hinge. 
         [0065]    The adjustment screw  60 , which is a threaded element, includes a knob  61 , a shaft  62 , a screw thread  63  that has a top end  63   a  and bottom end  63   b , a stop ring  64 , and a retention knob  65 . The screw  60  fits into the spring guide  87 , where it is retained with the shaft  62  being held inside the retention hole  90  between the stop ring  64  and the retention knob  65 , and with the outside edges  66  of the screw threads  63  in contact with an interior sidewall of the spring guide  87 . Each of the screw threads  63  may optionally have an outside edge  66   a  that can be angled to provide a flat surface to bear against the interior sidewall of the spring guide  87  and top surface  86  of the strap  80 . The retention hole  90  accepts the retention knob  65  of the screw  60  by virtue of the resilience of the materials used to construct the housing  82  and the tapered shape of the retention knob  65 . The length of the shaft  62  between the stop ring  64  and retention knob  65  may be greater than the thickness of the sidewall surrounding the retention hole  90  to permit limited travel of the screw  60  along its longitudinal axis. The screw  60  can be formed of any rigid material and examples including, but not limited to, a metal or a glass-filled nylon or a polycarbonate or other rigid natural or synthetic substance may be preferred. 
         [0066]    The screw threads  63  may further include a taper along its outside diameter extending as much as from the top end  63   a  to the bottom end  63   b , the taper having an angle of between approximately 0.01 degrees and approximately 45 degrees, more particularly between approximately 1 degree and approximately 15 degrees, the wider portion of the taper occurring at the top end  63   a  and the narrower portion occurring at the bottom end  63   b . The interior sidewall of the spring guide  87  has a shape which matches the shape of the outside diameter of the screw threads  63 ; more particularly, a taper, if any, on the screw threads  63  shall be similarly present in the shape of the interior sidewall of the spring guide  87  so that the screw threads  63  may fit snugly within the spring guide  87 . Further, the outside edge  66   a  of the screw threads  63  may be truncated, so as to provide each screw thread  63  a flat surface, instead of a sharp edge, with which to bear against the interior sidewall of the spring guide  87  and the top surface  86  of the strap  80  between the strap threads  81 . In this embodiment a double-helical thread shape with truncated outer and inner edges  66   a ,  66   b  is used for the screw threads  63 , although it must be appreciated by those skilled in the art that different thread shapes may also be used for this purpose. 
         [0067]    The screw  60  may be able to move longitudinally within the spring guide  87  because the length of shaft  62  between the stop ring  64  and retention knob  65  may be greater than the thickness of the sidewall surrounding the screw retention hole  90 . As the strap  80  is pulled through the housing  82 , as when being tightened around a wrist  100 , the motion of the strap  80  pulls the screw  60 , by virtue of the contact between the strap threads  81  and screw threads  63 , in the same direction. The taper of the screw threads  63  generally removes the screw threads  63  from contact with the interior sidewall of the spring guide  87 , and together with the longitudinal movement of the screw  60  reduces resistance to the motion of the strap  80  being pulled through the housing  82 . The strap threads  81  traverse across the screw threads  63 , the resistance to this travel being further reduced by the concave notch  93  in the strap threads  81 . Further, the entire spring guide  87  will flex along its arcuate axis  92  as the screw threads  63  pass over the strap threads  81  because of the flexion provided by the spring hinge  88 . This permits a ratcheting type of motion of the strap  80  moving through the housing  82  due to the screw threads  63  engaging with the strap threads  81  thus permitting rapid tightening and securement of the device  10 . 
         [0068]    When the strap  80  has been suitably and fittingly (e.g. snugly) pulled through the housing  82  and the device  10  is under compression as when tightened around a wrist  100 , the screw threads  63  engage strap threads  81  thereby preventing movement relative to each other. In this state, tension on the strap  80  increases and forces the screw threads  63  against the interior sidewall of the spring guide  87 , in turn preventing further movement of the strap  80  because the screw threads  63  trap the strap threads  81 . Because of their tapers, the screw threads  63  bear against the interior sidewall of the spring guide  87  to provide frictional resistance to both rotational and longitudinal motion of the screw  60  before the stop ring  64  bottoms out against the interior sidewall surrounding the screw retention hole  90 . As tension increases, to a point, friction of the screw threads  63  against the interior sidewall of the spring guide  87  increases, providing additional securement of the device  10  around the wrist  100 . Thus, by fitting the taper of the screw threads  63  to the taper of the interior wall of spring guide  87  so as to provide rotational friction with which to lock the tapered surfaces of the screw  60  and interior sidewall of the spring guide  87  together, the strap  80  is fastened. Alternatively, the screw threads  63  and the interior sidewall of spring guide  87  may have no taper, so that, for example, their shapes, instead of being tapered, may be generally cylindrical. 
         [0069]    The compression pad  20  has loops  22  which permit the strap  80  to fit within the strap openings  23  formed by the loops  22 , allowing the compression pad  60  to slide along the length of the strap  80 . The openings formed by the loops in accordance with one embodiment of the invention are dimensioned in width and height as detailed elsewhere herein. The compression pad  20  further includes a notch  21 , a compression surface  24  on the bottom, lateral sidewalls  25 , and end sidewalls  26 . The compression surface  24  is placed directly over the puncture site  106  and blood vessel  102  so as to reduce or halt blood flow  108  by occluding the vessel to permit a clot to form at the arteriotomy. The notch  21  helps the user position the compression pad  20  in the proper location over the puncture site  106  by providing a guide within which the cannula may slide during its removal from the blood vessel  102 . In an alternative embodiment, the compression surface  24 A is placed proximal to the puncture site  106  in the blood vessel  102  with the notch  21 A enabling visual and physical access to the puncture site  106 . The compression surface  24 A, when the device  10  is under compression, thus partially or completely blocks the flow of blood  108 . 
         [0070]    The ulnar pad  40  on the housing  82  has ulnar surfaces  43  which are placed directly against the ulnar surface of the wrist  100 , serving both as a cushion and, with the height A  44  in conjunction with the height of the compression pad  20 , provides standoff to enable a space  105  to exist between the strap  80  and the surface of the wrist  100 , thereby enabling blood flow through the ulnar artery  101  and veins  103  during compression of the blood vessel  102 , in this example the radial artery. The tail  41  of the ulnar pad provides a barrier to prevent a patient&#39;s skin and hair from being caught in the insertion opening  91  (refer briefly to  FIGS. 5 and 9 ). The ulnar pad  40  optionally can include a padding material attached to its surface to provide cushioning and thus greater comfort to the person wearing the device  10 . 
         [0071]    Examples of materials from which the compression pad  20  can be formed include polypropylene, polyester, nylon, or other thermoplastics, metals, or fibrous materials, or any other suitable material. It will be appreciated by those skilled in the art that a variety of materials and shapes of the pads, in addition to those disclosed and illustrated herein, may be employed and that alternatively, these pads may be integrally formed as non-separable parts of the strap  80 . The compression surface  24  optionally can include a coating, or padding, gauze, sponge, hemostatic material, or other suitable and useful material attached to or integrally formed with it. All such alternative compression pad embodiments are contemplated as being within the spirit and scope of the invention. 
         [0072]    The device  10  is secured around a wrist  100  by threading the tip  85  through the insertion opening  91  and pushing it through the housing  82  and pulling it through the strap-tip exit opening  83 . The screw threads  63  of the screw  60 , which is retained inside the spring guide  87 , engage with the strap threads  81  and secure it in place within the housing  82 . 
         [0073]    When the strap  80  is pulled tight, the screw  60  is pulled in the direction that the strap is moving by friction of the strap threads  81  against the screw threads  63  and moves to the extent permitted by the length of the shaft  62 , between the stop ring  64  and retention knob  65 , contained inside the screw retention hole  90 . 
         [0074]    When the user stops pulling the strap  80  through the housing  82 , the compression of the device  10  against the circumference of the wrist  100  causes the screw  60 , while its screw threads  63  are still engaged with the strap threads  81 , to move towards the bottom of the spring guide  87  until stopped by the screw threads  63  coming into contact with the interior sidewall of the spring guide  87 . This provides a securement means, which permits a user to quickly tighten the device  10  and fasten it at the circumference to which it has been tightened. The securement enabled by a taper included in the shape of the screw threads  63  and the interior sidewall of the spring guide  87  has been described previously herein. 
         [0075]    In addition to providing rapid securement, the screw threads  63  engaging with the strap threads  81  provide an adjustment means to enable very gradual adjustment of the circumference of the fastened device  10  around the wrist  100 . A user, by twisting the knob  61  causes the screw threads  63  to move against the strap threads  81  thereby moving the strap  80  relative to the housing  82 . This is done without effecting any inadvertent release of securement of the device  10 . 
         [0076]    Thus, a securement means integrated with an adjustment means is created by the screw threads  63  located on the screw  60 , which is retained in the spring guide  87 , engaging with the strap threads  81 . The strap  80 , specifically that portion extending from the exit opening  83 , is pulled through the housing  82  by the user, which action causes the concave notches  93  in the centers of the strap threads  81  to travel over the screw threads  63 , thereby permitting movement of the strap  80  through the housing  82 . Flexion along the arcuate axis  92  of the spring hinge  88  provides sufficient space to allow movement of the strap  80  when the edge of a screw thread  63  is directly over the concave notch  93  of the strap thread  81 . This is further assisted by the angle of the screw thread  63 . Said flexion further causes the spring hinge  88  to move to its original position when the outer edge  66   a  of a screw thread  63  passes over the concave notch  93  of a strap thread  81  coming to a rest against the top surface  86  of the strap  80  as shown in  FIGS. 11A and 11B , thereby securing the strap  80  at the desired circumference around the wrist  100 . 
         [0077]    A rapid release of the strap  80  through the housing  82  may be achieved by flexing the spring hinge  88  along its arcuate axis  92  and pulling on the portion of the strap  80  extending from the insertion opening  91  of the housing  82 . A user may flex the spring hinge  88 , as in the manner of a live hinge, by leveraging the knob-end of the screw  60  along its arcuate axis  92 , which causes it to move against the adjacent interior sidewall of the spring guide  87  in which it is inserted. Alternatively, in the event that the composition and structure of the spring guide  87  permits—for example by the use of a flexible material such as a polypropylene or a nylon—the user can squeeze the lateral exterior sidewalls of the spring guide  87  towards each other, and by so grasping them can pull the spring guide  87  upwards, such motion being permitted by the spring hinge  88  acting as a live hinge. By either approach, the spring guide  87  is moved away from the top surface  86  of the strap  80 , such action disengaging the screw threads  63  from the strap threads  81  and top surface  86  thus permitting the strap  80  to move freely within the housing  82 . 
         [0078]    Thus, a rapid release means is created by either of two alternate actions: i) the user moves the screw  60  to deflect the spring guide  87  away from the strap  80  contained in the housing  82 , such deflection permitted by the flexion of the spring hinge  88 , the screw  60  thereby acting as a lever; and/or ii) the user squeezes the lateral exterior sidewalls of the spring guide  87 , and by so grasping them with their fingertips pulls it away from the strap  80 , such deflection permitted by the flexion of the spring hinge  88 . 
         [0079]    An alternative embodiment of the device  10  includes a bolt  70  which is placed inside the housing  82  instead of the adjustment screw  60  so that the spine  68  is in contact with the interior sidewall of the spring guide  87  and the bolt threads  67  are in contact with the strap threads  81 . The bolt  70  provides a fastening means, but without the compression adjustment enabled by the screw  60 . The bolt  70  is fastened in the housing  82  by means of the shaft  62  being inside the screw retention hole  90 , the retention knob  65  on the outside and the stop ring  64  on the inside. Though fastened in the housing  82 , the bolt  70  may move freely around its longitudinal axis, and to the extent the length of the shaft  62  between the stop ring  64  and retention knob  65  is longer than the thickness of the sidewall surrounding the screw retention hole  90 , along its longitudinal axis. The bolt  70  thus generally provides a securement means similar to that of the adjustment screw  60 , which is described elsewhere herein, but does not provide the adjustment features to the same extent as the adjustment screw  60 . In this embodiment, the bolt  70  has a tapered shape, similar to an embodiment of the adjustment screw  60  previously described, though a non-tapered shape would suffice, for example a cylindrical shape. 
         [0080]    A rapid release of the strap  80  through the housing  82  may be achieved by flexing the spring hinge  88  along its arcuate axis  92  and pulling on the portion of the strap  80  extending from the insertion opening  91  of the housing  82 , in a fashion described above with the adjustment screw  60  in place. With the bolt  70  in place, the rapid release is achieved in a similar fashion, except that the user pushes on the quick-release tab  69  towards the spring hinge, thereby lifting the bolt  70 , thus flexing the spring hinge  88  in its vertical axis  92  by means of the spine  68  bearing against the interior sidewall of the spring guide  87 . Alternatively, the bolt  70  may be rotated around its longitudinal axis, to expose the non-threaded spine  68  to the strap threads  81  thereby disengaging from them and allowing the strap  80  to move freely within the housing  82 . Such rotation may be effected by pushing on the quick-release tab  69  from side to side. Thus the bolt  70  used as an alternative to the adjustment screw  60  provides a securement means and a release means, but does not provide a means of making fine adjustments without release of the securement means. 
         [0081]    A method of using the device of the present invention includes the following steps: 
         [0082]    i) Placing the compression surface  24  on the wrist  100 . A user fits the device  10  around a wrist  100  of a patient and by pulling the tip  85  through the housing  82 , fastens it loosely so that the compression pad  20  may be moved to the desired point overlying the blood vessel  102 , for example a radial artery. The method provides that the device  10  need not necessarily be pulled tight initially, and this first step serves to place and keep in place the compression surface  24  of the compression pad  20  in the correct position relative to the puncture site  106 , in which the cannula or needle is still located. 
         [0083]    ii) Tightening the device  10  while pulling out the cannula. The user pulls out the cannula or needle from the puncture site  106  and simultaneously pulls the tip  85  of the strap  80  with their hand while holding the housing  82  or knob  61  in place with their thumb, such that flow of blood from the puncture site  106  is stopped. Alternatively a second person may pull out the cannula as the user pulls the tip  85  with one hand while holding the housing  82  in place with their other hand, or the user may press down on top of the compression pad  20  forcefully to compress the blood vessel  102  while removing the cannula, and then after discarding the cannula while continuing to press down onto the compression pad  20 , pulls the tip  85  in the fashion described above. 
         [0084]    iii) Adjusting the amount of compression applied to the surface of the wrist  100 . The user, by twisting the knob  61 , may tighten or loosen the device  10  to adjust the amount of compression applied to the surface of the wrist  100 , for example, when adjusting compression so that the blood vessel  102  retains a degree of patency during the compression period while hemostasis occurs at the puncture site  106 . Compression may further be gradually reduced during the period in which hemostasis occurs to help avoid complications. 
         [0085]    iv) Releasing the device  10  from the wrist  100 . The user, by either tilting the screw  60  away from the strap  80 , or by squeezing with their fingertips the lateral external sidewalls of the spring guide  87 , disengages the screw threads  63  from the strap threads  81  enabling the user to pull the strap  80  through the housing  82  to release the device  10  from the wrist  100  of the patient, and can then remove the device  10  entirely. 
         [0086]    It will be understood that the present invention is not limited to the method or detail of construction, fabrication, material, application or use described and illustrated herein. Indeed, any suitable variation of fabrication, use, or application is contemplated as an alternative embodiment, and thus is within the spirit and scope of the invention. Accordingly, while the present invention has been shown and described with reference to the foregoing embodiments of the invented apparatus and method of use, it will be apparent to those skilled in the art that other changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined in the claims. 
         [0087]    It is further intended that any other embodiments of the present invention that result from any changes in application or method of use or operation, configuration, method of manufacture, shape, size, or material, which are not specified within the detailed written description or illustrations contained herein yet would be understood by one skilled in the art, are within the scope of the present invention.