Abstract:
An immersion bag system for use with an ultrasound probe to overcome near field artifact includes a flexible thin wall thickness immersion bag with an attached flexible collar having an integral internal seal. The immersion bag contains a gel or other ultrasound transmission medium and is sealingly and removably attached to the tip end of an ultrasound probe by use of the flexible collar having the integral internal seal. The immersion bag is able to conform to a cornea as well as to other surfaces whether flat or irregular, thereby enabling an ultrasound probe to be used easily on such surfaces. An ultrasound probe in use with the immersion bag system is maintained at a distance above the contact surface of the immersion bag and is positionable about the vertical axis while the immersion bag maintains stationary conformal contact with the structure against which it is in contact.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     None. 
     FIELD OF THE INVENTION 
     The present invention primarily applies to the medical device field, and more particularly, pertains to an immersion bag system having an immersion bag of acoustically invisible, i.e., transparent, material and a sealing collar with pressure release valve that encapsulates the distal end of and is incorporated into use with an ultrasound probe. The immersion bag system, suitable for containment of a gel or other aqueous medium, overcomes near field artifact allowing the examination of shallow anatomical structures. 
     Definition of “near field artifact.” Typically, a stationary ultrasound probe passes or scans approximately 10 degrees during ultrasound scanning, but by physically moving the ultrasound probe tip back and forth via a motor or other suitable means, a range of 120 degrees can be examined. However, when the ultrasound probe transducer head moves, the consequential pulsating of the ultrasound waves causes the ultrasound waves to collide with one another, thus creating interference which results in an acoustic dead zone. Structures contained within this dead zone cannot be visualized; this is termed “near field artifact”. Therefore, examining shallow/superficial tissue with a moving ultrasound probe, anatomical structures within the near field artifact cannot be visualized because of the near field artifact. 
     This invention has medical and industrial applications by enhancing the ability to exam shallow/superficial structures amenable to ultrasound evaluation. Medical and industrial sonogram examinations may be improved by this method of overcoming near field artifact (defined previously). This includes:
     a. anterior ocular structures, e.g., the cornea, iris, lens, ciliary body;   b. skin lesions, e.g., skin cancers, cysts, or neoplasms;   c. vascular structure/flow assessment; and,   d. industrial monitoring of flow characteristics in tubing.   

     DESCRIPTION OF THE PRIOR ART 
     Ultrasound scans of the eye or other areas of the body are performed using an ultrasound scan probe and a coupling medium placed between the ultrasound probe tip and the surface of the area being scanned during examination. The medium, such as a gel or other less viscous aqueous medium, allows for the transmission of ultrasound waves between the ultrasound probe and through human tissue or other structures. To reduce or eliminate the near field artifact, the ultrasound probe tip and the superficial structures under examination (such as blood vessels or anterior aspects of the eye) must be separated at a distance from each other and not in direct contact. A common method of accomplishing this is to use a cylinder-shaped cup that is open on both ends and contains a gel or other suitable aqueous medium, which is then placed over the area of the examining surface. The use of an open ended cylinder-shaped cup requires that the operator fill the cup with gel or other suitable aqueous medium. An excessive filling of the cup may result in undesirable overrun of the cup when the tip of the ultrasound probe is introduced therein. An insufficient filling of the cup results in less than desirable ultrasound scan examination because the near field artifact opaque zone cannot be overcome, thus preventing an examination of the structure under study. More importantly, if a cylinder with an open bottom, i.e., a cup, is used, the gel or other suitable aqueous medium must be at a depth to allow a sufficient probe distance from the exam surface to overcome the opaque zone created by the near field artifact. The acoustically transparent immersion bag of the present invention eliminates the need for tedious and correct medium filling to a proper level and provides for ultrasound probe separation from the exam surface to overcome the near field artifact, thereby allowing visualization of superficial structures of the body and/or other structures during the ultrasound exam. 
     SUMMARY OF THE INVENTION 
     The general purpose of the present invention is the creation of an immersion bag system, portions of which are fabricated from acoustically invisible, i.e., transparent, material, such as polyethylene, hydrophilic plastic or other suitable thin flexible material, for encapsulating the tip of an ultrasound probe. An immersion bag, suitable for containment of a gel or other aqueous medium, overcomes near field artifact thereby allowing the examination of shallow/superficial structures. The immersion bag is permanently attached to a flexible collar which seals around the distal end of the ultrasound probe outer body. 
     According to one or more embodiments of the present invention, there is an immersion bag system having a flexible compressible collar and an immersion bag attached thereto which are collectively used to encapsulate the tip portion of an ultrasound probe. The immersion bag system, portions of which can contain preloaded or site-loaded gel or other suitable aqueous medium, engages and surrounds a portion of the distal end of an ultrasound probe to an adequate depth to overcome the near field artifact. The mutually secured immersion bag and flexible collar are comprised of flexible and pliable materials. Specifically, the flexible collar includes an open end for inserting an ultrasound probe and includes an integral seal. The acoustically invisible immersion bag is attached to the flexible collar, each having annular configurations. A lip of the immersion bag is permanently secured within the flexible collar by a capture ring and other suitable attachment means. Additionally, the seal, which is integral to the flexible collar frictionally engages the body of the ultrasound probe upon the ultrasound probe being introduced therein. By inserting the ultrasound probe into the partially liquid filled immersion bag, slight hydraulic (internal) pressure is created, effectively eliminating bag material wrinkles, which is another cause of acoustical near field artifact, thereby forming and ensuring a smooth surface shape of the immersion bag. To maintain immersion bag shape and integrity, venting is provided by one or more self-sealing valves to release air, excess gel, or other excess aqueous medium from the immersion bag during insertion of the ultrasound probe or during operation of the invention in order to maintain positive internal immersion bag pressure. One or more self-sealing valves are calibrated to provide positive internal pressure at a safe immersion bag material limit. The internal pressure and bag tension also provides resistance and tactile feedback to the operator when moving the probe toward the immersion bag bottom. This internal immersion bag pressure and bag tension offsets the ultrasound probe tip from the examined surface, thus overcoming near field artifact and maintaining spacing between the transducer and the immersion bag end. The end of the immersion bag is conformally reshaped to mirror and envelop the examining surface upon contact while remaining wrinkle free. Moreover, being flexible and pliable, the immersion bag conforms to irregularly shaped anatomical areas such as, but not limited to, the nose region or eyelid. 
     The flexible immersion bag accommodates off-center and angular positioning of the ultrasound probe for off-center ultrasound scans. Thus, while the immersion bag is immobile, the ultrasound probe is free to move within the immersion bag. This minimizes potential damage to sensitive and delicate tissues such as the cornea. The ultrasound probe and immersion bag containing the liquid medium can easily be moved and repositioned on different anatomical areas to be examined. 
     One significant aspect and feature of the present invention is an acoustically transparent immersion bag of an immersion bag system that encapsulates one end of an ultrasound probe. 
     Another significant aspect and feature of the present invention includes an acoustically transparent immersion bag system where a collar including a seal and a capture ring in cooperation with an immersion bag surround and engage a portion of an ultrasound probe. 
     Still another significant aspect and feature of the present invention is a flexible collar and closely associated structure which effectively secures and seals to the ultrasound probe body. 
     Still another significant aspect and feature of the present invention is an immersion bag which can be preloaded on site with a gel or other aqueous medium. 
     Yet another significant aspect and feature of the present invention is an immersion bag wherein gel or other aqueous medium is contained and encapsulated about and between the distal end of an ultrasound probe and the interior of the immersion bag. 
     Another significant aspect and feature of the present invention is a flexible collar including controlled pressure venting for air, gases, gels or other aqueous medium. 
     Yet another significant aspect and feature of the present invention is a flexible immersion bag that accommodates off-center positioning of an ultrasound probe for off-center ultrasound scans by the immersion bag remaining stationary and the ultrasound probe moving within the immersion bag so that there is no or minimal abrasive contact with delicate or sensitive structures. 
     Another significant aspect and feature of the present invention is an immersion bag including a flexible collar with one or more self-sealing valves which provide for passive control of the pressure in an immersion bag during probe insertion and thereby prevent the immersion bag from bursting by allowing air and excessive filler medium to escape. 
     Another significant aspect and feature of the present invention is internal immersion bag hydraulic pressure and bag material tension creating buoyancy and resistance on the ultrasound probe when the operator is moving the probe deeper into the immersion bag and contacting the examined surface. This offsets the height of the ultrasound probe from the examined surface. 
     Having thus briefly described embodiments of the present invention and having mentioned some significant aspects and features of the present invention, it is the principal object of the present invention to provide an acoustically transparent immersion bag system that overcomes near field artifact by surrounding the tip portion of an ultrasound probe with gel or liquid contained in an immersion bag that is secured to and about the ultrasound probe via a flexible collar that contains self-sealing valve structure for excess air or excess liquid. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein: 
         FIG. 1  is an isometric view of an immersion bag system, the present invention, shown in use surrounding the tip of an ultrasound probe; 
         FIG. 2  is a partially exploded view of an immersion bag system and a typical ultrasound probe for use therewith; 
         FIG. 3  is a cross section view of a one-piece flexible collar taken along line  3 - 3  of  FIG. 4  in order to show both the general structure of the one-piece flexible collar and the structure of the valving extending through the wall thereof; 
         FIGS. 4 and 5  are top and bottom views, respectively, of the immersion bag one-piece flexible collar; 
         FIG. 6  is a partial cross section view showing engagement of an immersion bag system with the tip of an ultrasound probe; 
         FIG. 7  illustrates an ultrasound probe with its tip surrounded by an immersion bag system contacting the cornea of an eye for performing an ultrasound scan of the central portion of the eye; 
         FIG. 8  illustrates an ultrasound probe with its tip surrounded by an immersion bag system engaging the cornea of an eye, the ultrasound probe being angled within the stationary but flexible immersion bag for an ultrasound scan of a non-central portion of the eye; 
         FIG. 9  is a cross section view of an alternative embodiment of a one-piece flexible collar taken along line  9 - 9  of  FIG. 10 ; 
         FIGS. 10 and 11  are top and bottom views, respectively, of the alternative embodiment one-piece flexible collar; and, 
         FIG. 12  is a partial cross section view showing engagement of an immersion bag system using the alternative one-piece flexible collar with the tip of an ultrasound probe. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  is an isometric view of an immersion bag system  10 , the present invention, shown affixed to and in use with an ultrasound probe  12 . The lower region of the ultrasound probe  12  is sealed in close association with the following components comprising the immersion bag system  10 , each with flexible qualities, including: an immersion bag  16 , a flexible collar  18  having an integral seal  20 , and a capture ring  22 , all of which are shown in  FIG. 2 . The body  24  of the ultrasound probe  12  generally is tubular in shape and includes a transducer  26  at one end and houses other internal components associated with operation of the transducer  26 . The ultrasound probe body  24  includes suitable geometrically configured external structure about the upper region thereof. A control/power cable  28  exits one end of the ultrasound probe  12  for connection to external support components associated with operation of the transducer  26 . 
       FIG. 2  is a partially exploded view of the immersion bag system  10  which in use will frictionally engage the lower portion of the ultrasound body  24 . The structure of the immersion bag system  10  includes the immersion bag  16 , the flexible collar  18 , the seal  20  integral to the flexible collar  18 , and the capture ring  22 , collectively having features suitable for providing sealed communication of the immersion bag  16  with the lower portion of the body  24  of the ultrasound probe  12 . 
     The seal  20 , which is an integral portion of the flexible collar  18 , is of annular shape, is fashioned of a flexible material, such as, but not limited to, latex, rubber, plastic, or other suitable material, and includes aligned and connecting generally annular-shaped structure. 
     The immersion bag  16  is formed of a thin and flexible pliable acoustically transparent material, such as polyethylene, hydrophyllic plastic, or other suitable material which is capable of containing a gel or other suitable medium which allows the passage of ultrasound waves. The immersion bag  16  preferably has a general cylindrical shape for the greatest portion thereof and includes an end  30  which is dome shaped and an interior  32 . The top of the immersion bag  16  is reversed a short distance outwardly and about itself to form a lip  34  of annular shape extending about the upper region of the immersion bag  16  for accommodation of the capture ring  22 . The capture ring  22  is of annular shape fashioned of a flexible material, such as, but not limited to, rubber, latex, plastic or other suitable material. 
       FIG. 3  is a cross section view of the one-piece flexible collar  18  taken along line  3 - 3  of  FIG. 4 . The one-piece flexible collar  18 , also shown in detail in  FIGS. 4 ,  5  and  6 , is of annular shape fashioned preferably of a flexible material such as foam, preferably closed cell foam, or of other suitable flexible and pliable material. The cross section view of  FIG. 3  is taken along line  3 - 3  of  FIG. 4  in order to show both the general structure of the one-piece flexible collar and the structure of the valving extending through the wall thereof. The continuously formed flexible collar  18  is comprised of a plurality of geometrically configured structures including: a vertically oriented outer wall  36  which forms the periphery of the flexible collar  18 , a horizontally oriented top wall  38  which intersects the upper region of the outer wall  36  and extends inwardly a short distance, an angled transition wall  40  extending inwardly and downwardly from the top wall  38 , and the seal  20  extending downwardly from the lower portion of the transition wall  40 . The lower portion of the seal  20  is canted in slightly to ensure forcible flexed contact of the inner periphery of the seal  20  with the body  24  of the ultrasound probe  12 . Other annular regions are formed by the previously described structure of the flexible collar  18  including a top opening  42  incorporating the angled inner periphery of the transition wall  40  as a guide structure for insertion of a probe body, such as the probe body  24 , through the flexible collar  18 , and a middle opening  44  formed by the inner periphery of the seal  20 . A capture annulus  46  is formed near the junction of the inside surface of the outer wall  36  and the region underlying the top wall  38  for captured accommodation of the lip  34  of the immersion bag  16  in cooperation with the capture ring  22 . An expansive bottom opening  48  is provided extending between the lower region of the capture annulus  46  and below the bottom edge of the seal  20  through which a probe body, such as the probe body  24 , can pass unhindered. One or more self-sealing valves  50   a - 50   n  of arcuate and other structure are located along, about and extending through the transition wall  40 . The cross section of the self-sealing valves  50   a - 50   n , such as shown at self-sealing valve  50   n , discloses a triangular shape having an elongated arcuate opening  52  at the outwardly facing surface of the transition wall  40  narrowing to a closed but actuable elongated arcuate slit  54  at the inwardly facing surface of the transition wall  40 . The triangular shape extends as an extruded arcuate shape along a suitable arc, such as 20° for the purpose of example and illustration. 
       FIGS. 4 and 5  are top and bottom views, respectively, of the immersion bag flexible collar  18  including the seal  20 . Shown in particular are the self-sealing valves  50   a - 50   n  in the flexible collar  18  and the annular structure of the flexible collar  18 . The self-sealing valves  50   a - 50   n  vent the interior  32  of the immersion bag  16  when the tip of the ultrasound probe  12  is introduced into the interior  32  of the immersion bag  16 . Air, gases, liquids, gels, or other mediums or fluids can be displaced or vented through the self-sealing valves  50   a - 50   n  during introduction of the tip of the ultrasound probe  12  or during further operation of the invention. The size of the self-sealing valves  50   a - 50   n  is shown in exaggerated form for purpose of illustration. In actual practice, the slits at the upper portions of the self-sealing valves  50   a - 50   n , which alternatively can be in the form of narrow gaps or other suitable structure are parted by the force of the expelled or displaced air, gas, liquid, aqueous medium, gel, or the like, and modulate toward or to a closed state upon equalization between the immersion bag interior  32  and ambient pressure. The self-sealing valves  50   a - 50   n  could also be of different sized structure to operate across a pressure relief range. The purpose of the structure of the self-sealing valves  50   a - 50   n  is to prevent breakage of the immersion bag  16  by displacing air and to act as a fluid overflow. The self-sealing valves  50   a - 50   n  ensure adequate hydraulic force to remove wrinkles in the immersion bag  16  which result in acoustic artifacts (dead zones where shallow/superficial structures cannot be visualized). 
       FIG. 6  is a partial cross section view showing engagement of the immersion bag  16  with the tip of the ultrasound probe  12 . The immersion bag system  10  shown includes the flexible collar  18  including the seal  20 , the capture ring  22 , and the immersion bag  16  fully arranged and assembled using the structural features of such components in suitable engagement made possible by the elastic qualities of the involved components in combination with the fixation of the lip  34  of the immersion bag  16  within the capture annulus  46  by the capture ring  22  using heat staking, adhesive or other suitable attachment. Additionally, the lip  34  of the immersion bag  16  is secured in the capture annulus  46  and sealingly held against the inner surface of the outer wall  36  by the forcible positioning of and the forcible engagement of the capture ring  22 . The seal  20  flexes to sealingly accommodate and frictionally engage and seal against the body  24  of the ultrasound probe  12 . The tip of the ultrasound probe  12  is positioned within the interior  32  of the immersion bag  16 , wherein the transducer  26  is spaced sufficiently from the immersion bag end  30  to allow flexing of the bag end  30  about the surface of the eye and to prevent contact of the transducer  26  with the immersion bag end  30  during such flexing. 
     MODE OF OPERATION 
       FIGS. 7 and 8  illustrate the immersion bag system  10  in use with an ultrasound probe  12  engaging a cornea  56  of an eye  58  for an ultrasound scan, e.g., of the central and non-central aspects of the eye  58 , respectively. The immersion bag system  10  can be furnished as a sterile prepackaged disposable unit. The immersion bag  16  can be manually filled with a gel  60  or other suitable ultrasound transmission medium such as other aqueous medium, or the immersion bag  16  can be prefilled and covered by a removable top seal to contain the gel  60  or other aqueous medium within the immersion bag  16 , wherein the top seal is removed prior to introducing the end of the probe body  24  into the flexible collar  18  and into the immersion bag  16 . Also, a foil seal can hold an adequate amount of transducer coupling medium on the outside of the immersion bag  16 . During introduction of the end of the probe body  24  into the flexible collar  18  and the immersion bag  16 , the seal  20  flexingly seals against the body  24  of the ultrasound probe  12  to ensure that the gel  60  or other aqueous medium is contained within the interior  32  of the immersion bag  16 . The previously described self-sealing valves  50   a - 50   n  are parted when the internal pressure of the immersion bag  16  exceeds a certain level in order to maintain the integrity of the immersion bag  16  and releases enough air, gas, liquid, gel, or other aqueous medium to reduce the internal pressure of the immersion bag  16  to a safe level and to prevent the bag from bursting but still have an internal positive pressure within the immersion bag  16 . The ultrasound probe  12  is introduced a suitable distance (depending on probe frequency) into the interior  32  of the immersion bag  16  laden with gel  60  or other aqueous medium to overcome near field artifact where the transducer  26  preferably maintains a suitable spacing from the immersion bag end  30  and thus from the cornea  56  or other near surface. The invention comes in direct contact with the cornea  56  or other superficial structure, and upon initial contact, the bag end  30  of the immersion bag  16  intimately contacts and begins conformal reshaping to and about the surface of the cornea  56  or other superficial structure, while yet maintaining suitable spacing between the transducer  26  and the cornea  56  to overcome near field artifact. Also, the immersion bag  16  conforms to the surface under examination whether regular or irregular. The external ultrasound equipment is then energized after the ultrasound probe  12  is placed into the immersion bag  16  containing liquid/gel that has coupling fluid on the outside surface enabling an ultrasound scan of suitable width across the anterior aspects of the eye or other superficial structure. An ultrasound scan across a non-central portion of the eye  58  or other superficial structure can be accomplished, such as shown in  FIG. 8 , where the ultrasound probe  12  is repositioned to the side of the immersion bag  16  while maintaining the central original bag end  30  point of mutual contact. Contact with the examining surface remains in intimate contact due to the flexible nature of the immersion bag  16 . Thus, there is minimal drag across sensitive and delicate structures such as the cornea, reducing the chance of abrasion. Although the invention is described for use with an eye, the principles of the invention also apply to use about other superficial areas of a body, whether human or animal, for ocular, cutaneous or vascular purposes, or inanimate objects, such as tubing carrying fluid. When the ultrasound probe  12  is inserted through the flexible collar  18 , the seal  20  will be pulled downwardly, whereby this action will open one or more of the self-sealing valves  50   a - 50   n . Thus, as the ultrasound probe  12  is moved into position as it is inserted into the immersion bag  16 , slight positive pressure in the immersion bag  16  is maintained as the ultrasound probe  12  stops moving downwards but excess filler gel/liquid or air is simultaneously displaced. 
       FIG. 9  is a cross section view of an alternative embodiment of a one-piece flexible collar  62  taken along line  9 - 9  of  FIG. 10 . The one-piece flexible collar  62 , also shown in detail in  FIGS. 10 and 11 , is of annular shape fashioned preferably of a flexible material such as foam, preferably closed cell foam, or of other suitable flexible and pliable material. The cross section view of  FIG. 9  is taken along line  9 - 9  of  FIG. 10  in order to show both the general structure of the one-piece flexible collar  62  and the structure of the valving extending through the wall thereof. The continuously formed flexible collar  62  is comprised of a plurality of geometrically configured structures including: a vertically oriented outer wall  64  which forms the periphery of the flexible collar  62 , a horizontally oriented top wall  66  which intersects the upper region of the outer wall  64  and extends inwardly a short distance, a vertically oriented the inner wall  68  extending downwardly from top wall  66 , an angled transition wall  70  extending inwardly and downwardly from the lower portion of the inner wall  68 , and a downwardly extending seal  72  extending from the angled transition wall  70 . The lower portion of the seal  72  can be canted in slightly to ensure forcible flexed contact of the inner periphery of the seal  72  with the body  24  of the ultrasound probe  12 . Other annular regions are formed by the previously described structure of the flexible collar  62  including a top opening  74  incorporating the angled inner periphery of the transition wall  70  and the inner periphery of the inner wall  68  as a guide structure for insertion of a probe body, such as the probe body  24 , through the flexible collar  62 , and a bottom opening  76  formed by the inner periphery of the seal  72 . A capture annulus  78  is formed near the junction of the inside surface of the outer wall  64  and the region underlying the top wall  66  for captured accommodation of the lip  34  of the immersion bag  16  in cooperation with the capture ring  22 . One or more self-sealing valves  80   a - 80   n , preferably of arcuate structure, are located along, about and extending vertically through the inner face of the seal  72 . The cross section of the self-sealing valves  80   a - 80   n , such as shown at self-sealing valve  80   a , discloses an elongated arcuate structure. The self-sealing valves  80   a - 80   n  are shown in the open position such as when venting excess pressures or fluid medium therethrough. In the non-venting position, the shape of the self-sealing valves  80   a - 80   n  would assume a flattened position but would modulate toward the open position, as shown, during release of pressure or of fluid medium. 
       FIGS. 10 and 11  are top and bottom views, respectively, of the immersion bag flexible collar  62  including the seal  72 . Shown in particular are the self-sealing valves  80   a - 80   n  in the flexible collar  62  and the annular structure of the flexible collar  62 . The self-sealing valves  80   a - 80   n  vent the interior  32  of the immersion bag  16  when the tip of the ultrasound probe  12  is introduced into the interior  32  of the immersion bag  16 . Air, gases, liquids, gels, or other mediums or fluids can be displaced or vented through the self-sealing valves  80   a - 80   n  during introduction of the tip of the ultrasound probe  12  or during further operation of the invention. The size of the self-sealing valves  80   a - 80   n  is shown in exaggerated form for purpose of illustration. In actual practice, the self-sealing valves  80   a - 80   n  which alternatively can be in the form of narrow gaps, slits, other suitable structure, are parted by the force of the expelled or displaced air, gas, liquid, aqueous medium, gel, or the like, and modulate toward or to a closed state upon equalization between the immersion bag interior  32  and ambient pressure. The self-sealing valves  80   a - 80   n  could also be of different sized structure to operate across a pressure relief range. The purpose of the structure of the self-sealing valves  80   a - 80   n  is to prevent breakage of the immersion bag  16  by displacing air and to act as a fluid overflow. The self-sealing valves  80   a - 80   n  ensure adequate hydraulic force to remove wrinkles in the immersion bag  16  which result in acoustic artifacts (dead zones where shallow/superficial structures cannot be visualized). 
       FIG. 12  is a partial cross section view showing engagement of an immersion bag system  10   a  with the tip of the ultrasound probe  12 . The immersion bag system  10   a  shown includes the flexible collar  62  including the seal  72 , the capture ring  22 , and the immersion bag  16  fully arranged and assembled using the structural features of such components in suitable engagement made possible by the elastic qualities of the involved components in combination with the fixation of the lip  34  of the immersion bag  16  within the capture annulus  78  by the capture ring  22  using heat staking, adhesive or other suitable attachment. Additionally, the lip  34  of the immersion bag  16  is secured in the capture annulus  78  and sealingly held against the inner surface of the outer wall  64  by the forcible positioning of and the forcible engagement of the capture ring  22 . The seal  72  flexes to sealingly accommodate and frictionally engage and seal against the body  24  of the ultrasound probe  12 . The tip of the ultrasound probe  12  is positioned within the interior  32  of the immersion bag  16 , wherein the transducer  26  is spaced sufficiently from the immersion bag end  30  to allow flexing of the bag end  30  about the surface of the eye and to prevent contact of the transducer  26  with the immersion bag end  30  during such flexing. The mode of operation of the immersion bag system  10   a  is substantially the same as described for the immersion bag system  10 , the only difference being that the flexible collar  62  is substituted for the flexible collar  18 . Although flexible collar  62  has been characterized as being an alternative to the flexible collar  18 , neither collar is to be construed as being preferred over the other; both have equal stature. 
     Various modifications can be made to the present invention without departing from the apparent scope thereof. 
     PARTS LIST 
     
         
           10  immersion bag system 
           10   a  immersion bag system 
           12  ultrasound probe 
           16  immersion bag 
           18  flexible collar 
           20  seal 
           22  capture ring 
           24  body 
           26  transducer 
           28  control/power cable 
           30  end 
           32  interior 
           34  lip 
           36  outer wall 
           38  top wall 
           40  transition wall 
           42  top opening 
           44  middle opening 
           46  capture annulus 
           48  bottom opening 
           50   a - n  self-sealing valves 
           52  opening 
           54  slit 
           56  cornea 
           58  eye 
           60  gel 
           62  flexible collar 
           64  outer wall 
           66  top wall 
           68  inner wall 
           70  angled transition wall 
           72  seal 
           74  top opening 
           76  bottom opening 
           78  capture annulus 
           80   a - n  self-sealing valves