Abstract:
The present invention is directed to an apparatus for metering the jugular venous pressure of a patient, and a method thereof. The apparatus comprises: a slider which comprises a scale for indicating the venous pressure of a patient; a pointer connected to the sliding member of the slider perpendicularly to the scale, for pointing on the filling level of the jugular venous pressure of the patient. The jugular venous pressure is indicated by positioning the patient at a certain angle, such as 30 to 45 degrees with reference to the floor, placing the tip at the sternal-angle of the patient while the slider is held vertically, sliding the pointer until pointing on the top of the filling level of the jugular vein of the patient.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to the field of metering instruments for medical purposes. More particularly, the present invention relates to a gauge for measuring Jugular Venous Pressure (JVP). 
       BACKGROUND OF THE INVENTION 
       [0002]    Heart failure is a condition that can result from any structural or functional cardiac disorder that impairs the ability of the heart to fill with or pump a sufficient amount of blood throughout the body. The jugular vein provides information about right atrium and right ventricular function and venous pulsation can be detected in the jugular vein. 
         [0003]    To diagnose heart failure, physicians regularly use two rulers to measure the height from the sternal-angle (the bony ridge adjacent to the second rib where the manubrium joins the body of the sternum) to the filling level of the jugular vein when the patient is positioned at a 45 degree angle. An elevated JVP is the classic sign of venous hypertension, e.g. right-sided heart failure. The optimal JVP measurement is to position the patient to an angle of or under 45 degrees, and measure the height of the perpendicular line forming when the bottom of the first ruler is placed on the sternal-angle with the second ruler placed at a right angle with the first, pointing at the distanced edge of the filled jugular vein. In this way, the filling level of the jugular vein is determined. In healthy people, it is 3 to 4 centimeters above the sternal-angle. Measurements of over 5 centimeters above the sternal-angle may indicate heart failure. 
         [0004]    This type of measurement is based on the classical method for quantifying the JVP as described by Borst &amp; Molhuysen in 1952. (Borst J, Molhuysen J. “Exact determination of the central venous pressure by a simple clinical method.”  Lancet  1952 Aug. 16; 2 (7): 304-9). The method, as modified later, provides a diagnostic tool for determining heart failure by discerning the jugular filling level. 
         [0005]    The JVP is easiest to observe if one looks along the surface of the sternocleidomastoid muscle, as it is easier to appreciate the movement relative the neck when looking from the side (as opposed to looking at the surface at a 90 degree angle). As in judging the movement of an automobile from a distance, it is easier to see the movement of an automobile when it is crossing one&#39;s path at 90 degrees (i.e., moving left to right or right to left), as opposed to coming toward one. This is a simple method to appreciate the indirectly observed pressure over the venous system. 
         [0006]    With the present procedures of measurement, a physician must have in his hands two rulers upright each other, point one to the sternal-angle and the other to the filling level edge of the jugular vein, and at the same time measure the height of the crossing point between the two rulers. This procedure is technically complicated because the physician is supposed to see that the vertical ruler, indicating the height from the sternal-angle, is indeed perpendicular to the ground, when the patient is lying at 45 degrees to the ground. The complication of holding two rulers at the time of measurement makes the procedure awkward, and the need to keep the rulers available to the physician at all times renders the procedure even more exhausting. 
         [0007]    It is an object of the present invention to provide a Jugular Venous Pressure (JVP) gauge, which is operated in an easy and simple way. 
         [0008]    It is a further object of the present invention to provide a Jugular Venous Pressure (JVP) gauge which is of pocket size. 
         [0009]    Other objects and advantages of the invention will become apparent as the description proceeds. 
       SUMMARY OF THE INVENTION 
       [0010]    The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods, which are meant to be merely illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other advantages or improvements. 
         [0011]    In one aspect (illustrated in  FIG. 1 ), the present invention is directed to an apparatus for metering the jugular venous pressure of a patient, the apparatus comprising:
       a slider ( 12 ) comprising a scale ( 34 ) indicating the venous pressure of a patient; and   a pointer ( 14 ) connected to the sliding member ( 22 ) of the slider ( 12 ) perpendicularly to the scale, for pointing on the filling level of the jugular vein pressure of the patient.       
 
         [0014]    The jugular venous pressure may be metered by positioning the patient at a certain angle (e.g., 30 degrees, 40 degrees) with reference to the floor, placing the tip at the sternal-angle of the patient while the slider is held vertically, and sliding the pointer until pointing on the top of the filling level of the jugular venous of the patient. 
         [0015]    According to one embodiment of the invention, scale ( 34 ) indicates the distance between each point of the scale to a tip ( 7 ) of the slider ( 12 ). 
         [0016]    According to an additional or alternative embodiment of the invention, the scale indicates normal jugular venous pressure of a patient. 
         [0017]    According to an additional or alternative embodiment of the invention, the scale indicates abnormal jugular venous pressure of a patient. 
         [0018]    According to one embodiment of the invention, the pointer ( 14 ) comprises a bar. 
         [0019]    The apparatus may further comprise a spirit level ( 10 ), for indicating verticality of the scale. 
         [0020]    The apparatus may further comprise a spirit level ( 10 ), for indicating horizontality of the pointer. 
         [0021]    The apparatus may further comprise a dowel ( 21 ) and a corresponding depression ( 18 ), for holding the pointer perpendicularly to the scale while rendering the metering. 
         [0022]    The apparatus may further comprise a dowel ( 21 ) and corresponding depression ( 19 ), for holding the pointer in parallel to the scale while the apparatus is idle. 
         [0023]    In one embodiment of the invention, pointer ( 14 ) is foldable. 
         [0024]    The apparatus may further comprise a slit ( 4 ) corresponding to the pointer, for use as housing to the pointer when folded. 
         [0025]    The apparatus may further comprise a clip ( 6 ), for attaching the apparatus to a fabric. 
         [0026]    The apparatus may further comprise a push button ( 13 ) for pushing the pointer  14  to protrude from the body of the slider, thereby allowing rotating the pointer  14  to be perpendicular to slider ( 12 ). 
         [0027]    In a preferred embodiment of the invention, the slider ( 12 ) is of pocket size (i.e., small enough to be carried in a garment pocket, such as about 14 cm). 
         [0028]    In another aspect (illustrated in  FIG. 9 ), the present invention is directed to an apparatus for metering the jugular venous pressure (JVP) of a patient, the apparatus comprising: a ruler ( 12 ) whose scale ( 34 ) indicates the distance between each point of the scale and its projection on an horizontal plane ( 46 ), wherein the angle between ruler ( 12 ) and plane ( 46 ) is at an angle ( 44 ). According to one embodiment of the invention, the angle is substantially 30 degrees. According to another embodiment of the invention, the angle is substantially 45 degrees. 
         [0029]    The apparatus may further comprise a spirit level ( 10 ) indicating the angle ( 16 ). 
         [0030]    In yet another aspect, the present invention is directed to a method for metering the jugular venous pressure of a patient, the method comprising the steps of:
       providing an apparatus comprising a first bar perpendicular to a second bar, the first bar comprising a scale indicating the distance between a tip thereof, the second bar slideable along the first bar;   positioning the patient at an angle, such as 30 degrees or 45 degrees, with reference to the floor; and   placing the tip of the first bar at the sternal-angle of the patient, while the first bar is held vertically sliding the second over the first bar until reaching the top of the filling level of the jugular vein of the patient;   at this position the jugular venous pressure is indicated by the value that the second bar points to on the scale.       
 
         [0035]    In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0036]    The objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings, in which: 
           [0037]      FIGS. 1 and 2  illustrate a jugular venous pressure gauge, according to one embodiment of the invention. While  FIG. 1  illustrates the gauge in an idle state,  FIG. 2  schematically illustrates the gauge in measuring state. 
           [0038]      FIG. 3  is an exploded view which further details the jugular venous pressure gauge of  FIGS. 1 and 2 . 
           [0039]      FIG. 4  is a sectional view of cross-section A-A of  FIG. 6 . 
           [0040]      FIG. 5  is a sectional view of cross-section B-B of  FIG. 6 . 
           [0041]      FIG. 6  is a top view of the jugular venous pressure gauge of  FIGS. 1 and 2 . It specifies two cross-sections, A-A and B-B. 
           [0042]      FIG. 7  illustrates a jugular venous pressure gauge, according to another embodiment of the invention. 
           [0043]      FIG. 8  pictorially illustrates a measurement carried out by the jugular venous pressure gauge of  FIG. 1 . 
           [0044]      FIG. 9  schematically illustrates a jugular venous pressure gauge, according to another embodiment of the invention. 
           [0045]      FIG. 10  pictorially illustrates a measurement carried out by a jugular venous pressure gauge of  FIG. 9 . 
       
    
    
       [0046]    It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. Reference numerals may be repeated among the figures to indicate corresponding or analogous elements. 
       DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0047]    In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the disclosure. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail, so as not to obscure the present disclosure. 
       The Structure of One Embodiment 
       [0048]    In the embodiments illustrated in  FIGS. 1 to 8 , the gauge is embodied as a pen, having two states: an idle state, and a measuring state. 
         [0049]      FIG. 1  schematically illustrates a jugular venous pressure gauge in its idle state, in accordance with a preferred embodiment of the present invention. 
         [0050]      FIG. 2  schematically illustrates the jugular venous pressure gauge of  FIG. 1  in its measuring state. 
         [0051]      FIG. 3  is an exploded view of the jugular venous pressure gauge of  FIG. 1 . 
         [0052]    In these figures, gauge  2  is designed as a pocket-size pen. 
         [0053]    Scale  34  denotes the distance between tip  7  of gauge  2  and pointer  14 . The JVP is commonly metered by centimeters. As such, in  FIGS. 1 to 7  the scale  34  is in centimeters, i.e., according to the metric system, but any other scale may be used. 
         [0054]    The basic structure of the embodiments illustrated in  FIGS. 1 to 9  is two parts: a body  12  and a pointer  14  which slides along body  12 . In order to measure the JVP of a patient by gauge  2 , pointer  14  should be placed perpendicularly to body  12 . In this situation, i.e., when axis  11  of body  12  and pointer  14  are perpendicular, pointer  14  slides along axis  11  of body  12 . The arrows in  FIG. 2  illustrate the direction of sliding. 
         [0055]    Element  22  is a cylinder whose external diameter is slightly smaller than the diameter of body  12  in order to be slideable along body  12 . Since cylinder  22  resembles a piston, it is also referred to herein as piston. Pointer  14  is connected to piston  22  by an axle  42 . Thus, pointer  14  may be rotated around axle  42 . 
         [0056]    Element  20  of cylinder  22  is a spring, which tightens cylinder  22  to the interior of body  12 . 
         [0057]    Element  22  also comprises a dowel  21  (seen in  FIG. 4 ), which corresponds to depressions  18  and  19  of pointer  14 , thereby providing two stop points: a stop point at which the angle between axis  11  of body  12  and pointer  14  is 0 degrees, and a stop point at which the angle between axis  11  of body  12  and pointer  14  is 90 degrees. In the measuring state, the angle between axis  11  and pointer  14  is 90 degrees, and in the idle state the angle is 0 degrees. 
         [0058]    Body  12  comprises a slit  4  which is used as housing for pointer  14  in the idle state of the gauge. 
         [0059]    Element  8  is a threaded cylinder. The threads  9  of cylinder  8  are used for securing cylinder  8  to body  12 . 
         [0060]    Element  13  is a push button whose external diameter is slightly smaller than the inner diameter of cylinder  8 , thereby being slideable along cylinder  8 . When the gauge is in the idle state (i.e., folded), pushing push button  13  inside the body results in exposing the tip of pointer  14 , thereby allowing to position pointer  14  to be perpendicular to body  12 . Of course, pointer  14  may be designed to be somewhat longer, thereby outstanding from body  12 . 
         [0061]    In the embodiment of  FIG. 1 , a spirit level  10  is attached to one end of push button  13 . The spirit level  10  helps keep body  12  vertical while carrying out a measurement. According to one embodiment of the invention, spirit level  10  is a tube. According to another embodiment of the invention, spirit level  14  is a sphere. The difference between a tube and a sphere is that while the tube indicates a tilt in one plane, a sphere indicates a tilt in the space. 
         [0062]    While in the embodiment illustrated in  FIGS. 1 and 2  the spirit level is attached to the push button  13 , in the embodiment illustrated in  FIG. 7  the spirit level is attached to pointer  14 . 
         [0063]      FIG. 7  schematically illustrates a jugular venous pressure gauge, in accordance with another preferred embodiment of the present invention. 
         [0064]    In this embodiment of the invention, the gauge comprises spirit-level  10  which is placed on the pointer, in contrast to the embodiment of  FIGS. 1 and 2  in which the spirit level is placed on body  12  of the gauge. 
       Measuring the JVP 
       [0065]      FIG. 8  illustrates a measurement carried out by the gauges illustrated in  FIGS. 1 to 7 . 
         [0066]    Firstly, the patient is placed at a tilt of 45 degrees with the floor. It should be noted that some physicians prefer a tilt of 30 degrees. 
         [0067]    While rendering the measurement, pointer  14  must be perpendicular to the axis of the body. Thus, a physician must rotate pointer  14  until body  12  and pointer  14  are perpendicular. 
         [0068]    While holding the gauge vertically (this can be indicated by the spirit level  10 ), the physician places the tip of the gauge&#39;s body  12  on sternal-angle  24  of patient  30 . 
         [0069]    While holding the gauge on the sternal-angle  24 , the physician slides pointer  14  along body  12  until the pointer  14  is at the filling level edge of the jugular vein (marked by numeral  46 ). 
         [0070]    At this time, the value that pointer  14  points at is the JVP. 
       The Structure of Another Embodiment 
       [0071]      FIG. 9  schematically illustrates a jugular venous pressure gauge, according to another embodiment of the invention. 
         [0072]    According to this embodiment, the gauge  2  is based on a ruler  12  whose scale  34  indicates the distance between a point thereon and a plane  46  in a situation wherein the ruler  12  is tilted at a degrees with the plane. As mentioned above, preferably α is 45 degrees, but some physicians prefer an angle of 30 degrees. 
         [0073]    A spirit level  10  may be added to ruler  12  in order to indicate the desired angle α. 
         [0074]    Since the scale indicates the distance between a point thereon and a plane that tilts in α degrees with the ruler, the physical distance of 1 cm of the scale is 1/sin α. 
         [0075]    As mentioned above, some physicians prefer to measure the JVP while the patient is tilted at 30 degrees with the floor. Accordingly, the gauge may be designed to correspond to 30 degrees rather than 45 degrees, or to correspond with any desirable degree. 
         [0076]      FIG. 10  pictorially illustrates a measurement carried out by a jugular venous pressure gauge of  FIG. 9 . 
         [0077]    The patient is placed at a tilt of 45 degrees with the floor. As mentioned, some physicians prefer a tilt of 30 degrees. 
         [0078]    While holding the gauge at the desired angle (45 or 30 degrees), the physician places the tip of the gauge&#39;s body  12  on sternal-angle  24  of patient  30 , and rotates the gauge along the tip until spirit level  10  indicates that the patient is at the desired angle. 
         [0079]    At this situation the filling level edge of the corresponding point of the jugular vein (marked by numeral  46 ) on scale  34  indicates the JVP. 
       The Scale 
       [0080]    In the embodiments illustrated herein, the scale indicates the JVP. Additionally or alternatively, a scale may indicate an acceptable or unacceptable result. For example, the range of acceptable JVP values may be in a different color than the scale (for example, acceptable value in green, possibility of heart failure in red, etc.) 
         [0081]    In the description and figures herein, the following numerals are mentioned:
       Numeral  2  denotes a jugular venous pressure gauge, according to embodiments of the present invention;   Numeral  4  denotes a slit in the body  12  of gauge  2 , which serves as housing for pointer  14 ;   Numeral  5  denotes a slit in cylinder  22 ;   Numeral  6  denotes a clip;   Numeral  7  denotes a tip of gauge  2 ;   Numeral  8  denotes a threaded cylinder;   Numeral  9  denotes the threads of cylinder  8 ;   Numeral  10  denotes a spirit level, for indication that the axis  11  of gauge  2  is vertical;   Numeral  11  denotes the axis of pen-gauge  2 ;   Numeral  12  denotes the body of the pen-gauge  2 ;   Numeral  13  denotes a push button whose external diameter is slightly smaller than the inner diameter of cylinder  8 , thereby being slideable along cylinder  8 ;   Numeral  14  denotes a bar used as a pointer;   Numeral  18  denotes a depression which corresponds to dowel  21 ;   Numeral  19  denotes a depression which corresponds to dowel  21 ;   Numeral  20  denotes an element which operates as a spring that presses element  20  to the walls of the interior of body  12 , and also presses element  20  towards pointer  14 ;   Numeral  21  denotes a dowel which corresponds to depressions  18  (secures pointer  14  in the measure state) and  19  (secures pointer  14  in the idle state);   Numeral  22  denotes a cylinder (referred to herein as piston) whose diameter is slightly smaller than the interior diameter of body  12 ;   Numeral  24  denotes the sternal-angle of a patient;   Numeral  28  denotes the fluid of the spirit level  10 ;   Numeral  29  denotes the bubble of the spirit level  10 ;   Numeral  30  denotes a patient;   Numeral  34  denotes a scale which indicates the distance between the tip of gauge  2  (marked as  7 ) and pointer  14 ;   Numeral  42  denotes an axle which connects pointer  14  to piston  22 ;   Numeral  44  denotes the angle between ruler  12  and the projection thereof on a horizontal plane  46  (illustrated in  FIG. 10 ); and   Numeral  46  denotes a horizontal plane (illustrated in  FIG. 10 ).       
 
         [0107]    While certain features of the invention have been illustrated and described herein, the invention can be embodied in other forms, ways, modifications, substitutions, changes, equivalents, and so forth. The embodiments described herein should be considered as illustrative and not restrictive.