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 by a mutually formed probe/seal valve to the tip end of an ultrasound probe. 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 
     This patent application is a continuation-in-part of application Ser. No. 11/356,873 entitled “Immersion Bag System for Use With an Ultrasound Probe” filed on Feb. 17, 2006, which is pending. 
    
    
     BACKGROUND OF THE INVENTION 
     1. 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 material and a flexible sealing collar which when engaged with a body of an ultrasound probe forms a deformable valve which can also serve as a pressure release valve. The bag 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 of any suitable viscosity, overcomes near field artifact allowing the examination of shallow anatomical structures. In operation of the invention the distal end of the ultrasound probe, including a transducer, is immersed in the gel or other aqueous medium. 
     Definition of “near field artifact”. Typically, a stationary ultrasound probe passes or scans over just 10 degrees during ultrasound scanning, but by physically moving the ultrasound probe transducer head 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 collide with one another creating interference which results in an acoustic dead zone. Structures contained within this dead zone cannot be visualized and 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, iris angle, 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.       

     2. Description of the Prior Art 
     Ultrasound scans of the eye or other areas of the body are performed using an ultrasound 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 cylindrical shaped cup that is open on both ends which can contain gel or other suitable aqueous medium and which is placed over the area of the examining surface. The use of an open cylindrical 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 and the coupling gel, e.g., methylcellulose, may be an eye irritant. 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. Further, with the open cylinder technique, the ultrasound probe may readily come into contact with the sensitive cornea of the eye. Transmission of microorganisms is possible with the open cylinder technique as sterilization of the ultrasound probe is difficult and time consuming. 
     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 material such as polyethylene, hydrophilic plastic or other suitable thin flexible material which encapsulate the tip of an ultrasound probe. The 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 closely associated ultrasound probe outer case. When the ultrasound probe is inserted into the immersion bag, the immersion bag becomes a cylindrical or other shaped bag with positive internal pressure. During an examination, this internal positive pressure in the immersion bag inhibits the ultrasound probe from moving forward and contacting nearby structures, such as the cornea of the eye. Also, the ultrasound probe is encapsulated by the sterile immersion bag, thus reducing the likelihood of transmission of microorganisms from patient-to-patient. 
     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 is collectively used to encapsulate the tip portion of an ultrasound probe. The immersion bag system, which can contain preloaded or site loaded gel or other suitable aqueous medium, engages and surrounds the distal end of the 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 the ultrasound probe and also includes an integral flexible seal. The acoustically invisible immersion bag is attached to the flexible collar, each having annular qualities. A lip of the immersion bag is permanently secured within the flexible collar by a rigid or semi-rigid capture ring or by other suitable attachment methods. Additionally, the flexible seal, which is integral to the flexible collar, frictionally engages the body of the ultrasound probe upon introduction therein to form a deformable probe/seal valve therebetween which is watertight. 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 a source of acoustical artifact, thereby forming and ensuring a smooth surface shape of the immersion bag. A consequence of positive internal hydraulic pressure is the resistance created on the ultrasound probe when moved into the immersion bag, thereby minimizing the possibility of physical contact by the ultrasound probe with the superficial structures under examination, such as the sensitive cornea of the eye. Canting or otherwise reorienting of the ultrasound probe with respect to the flexible seal and flexible collar can deformingly open the probe/seal valve to lower internal bag air pressure or can release excess gel or aqueous medium from the immersion bag. To maintain immersion bag shape and integrity, venting can be 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. The internal pressure and bag tension also provides resistance and tactile feedback to the operator when moving the ultrasound probe toward the immersion bag end. This internal immersion bag pressure and bag tension offsets the ultrasound probe tip from the examined surface, thus overcoming near field artifact, and due to resistance, maintains 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. Moreover, being flexible and pliable, the immersion bag conforms to irregularly shaped anatomical areas, such as, but not limited to, the cornea, nose region or eyelid. 
     The flexible immersion bag accommodates off-center and angular positioning of the ultrasound probe for off-center ultrasound scans such as a lesion on the side of the eye (sclera). Thus, while the immersion bag is immobile, the ultrasound probe can be angled within the immersion bag. The immersion bag end also can be rolled on the examined surface for acquiring angled ultrasound images at various angles while still maintaining a spaced relationship with the examined surface. 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 without consequence to the cornea. 
     One significant aspect and feature of the present invention is a sterile acoustically invisible immersion bag of an immersion bag system that fully encapsulates one end of an ultrasound probe. 
     Another significant aspect and feature of the present invention includes an acoustically invisible immersion bag system where a flexible collar including a flexible seal and a rigid or semi-rigid capture ring in cooperation with an immersion bag surrounds and engages the distal end portion of the ultrasound probe. 
     Still another significant aspect and feature of the present invention is the flexible collar and closely associated structure which effectively secures and seals to the ultrasound probe body to form a probe/seal valve which is deformable. 
     Still another significant aspect and feature of the present invention is an immersion bag system which can be preloaded or loaded 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 which can include controlled pressure venting for air, gases, gels or other aqueous medium. 
     Yet another significant aspect and feature of the present invention is where a flexible immersion bag accommodates off-center positioning of the ultrasound probe for off-center ultrasound scans; hence, the immersion bag is stationary and the ultrasound probe moves within the immersion bag or can be rolled on the examined area and achieve similar results so 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 that functions in cooperation with the body of an ultrasound probe to form a self-sealing valve which can by itself or in combination with additional valves with the flexible collar provide passive control of the internal pressure in the immersion bag during ultrasound probe insertion, thereby preventing the immersion bag from bursting by allowing air and excessive filler medium to escape. 
     Another significant aspect and feature of the present invention is the utilization of internal immersion bag hydraulic pressure and bag material tension creating buoyancy and resistance on the ultrasound probe when the operator is moving the ultrasound probe deeper into the immersion bag into close proximity with the examined surface. Further, once the ultrasound probe has been inserted into the immersion bag, the consequential positive hydraulic pressure is a safety feature minimizing the likelihood of the ultrasound probe making physical contact with nearby superficial structures such as the cornea of the eye. Thus, there is an offset of the ultrasound probe from the examined surface that overcomes near field artifact. 
     Another embodiment of the present invention includes additional aspects and features wherein: 
     Another significant aspect and feature of the present invention is the use of a maneuvering ring which surrounds a flexible collar and other closely associated components to provide a measured amount of rigidity in order that the user can grasp and position the immersion bag with respect to the eye. 
     Another significant aspect and feature of the present invention is the use of a maneuvering ring having an interior annular receptor groove which engages, couples and mates with an exterior annular ring of the flexible collar for mutual joining thereof in order to fasteningly accommodate the lip of the immersion bag and other closely associated components. 
     Another significant aspect and feature of the present invention is the use of an O-ring or band to depress a portion of the immersion bag lip into an annular interior groove of a capture ring to secure the immersion bag to the capture ring. 
     Yet another significant aspect and feature of the present invention is the use of an immersion bag substantially having a conical shape for the greatest portion thereof which includes an end which is arcuate in profile, whereby such an arcuate end reversibly conforms to the shape of the cornea. 
     Yet another significant aspect and feature of the present invention is that examination of ocular structures does not require coupling gel on the bag outer surface. 
     Having thus briefly described one or more 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 a acoustically invisible immersion bag system that overcomes near field artifact by surrounding the tip portion of an ultrasound probe tip with gel or liquid contained in an immersion bag removably secured by the use of a probe/seal valve to and about an ultrasound probe via a flexible collar that may contain self-sealing valve structure for venting 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 provided to show a partially exploded view of the ultrasound immersion bag system and a typical ultrasound probe for use therewith; 
         FIG. 3  is a cross section view along line  3 - 3  of  FIG. 4  in order to show both the general structure of a flexible collar and to show valve structure extending through a flexible collar wall; 
         FIGS. 4 and 5  are top and bottom views, respectively, of the immersion bag flexible collar; 
         FIG. 6  is a partial cross section view showing the engagement of the immersion bag system with the tip of the ultrasound probe; 
         FIG. 7  illustrates a sterile immersion bag system surrounding the tip of an ultrasound probe and contacting the cornea of an eye as utilized during an ultrasound scan of the central portion of the eye and illustrating how the near field artifact is overcome; 
         FIG. 8  illustrates the ultrasound probe with the immersion bag system in close engagement with a cornea of an eye for an ultrasound scan of a noncentral portion of the eye where the ultrasound probe is depicted at an angle within the stationary but flexible immersion bag and maintaining positive pressure to minimize the chance of damaging sensitive/delicate tissue such as the cornea of the eye. 
         FIG. 9 , an alternative embodiment, is a cross section view of a one-piece flexible collar; 
         FIGS. 10 and 11  are top and bottom views, respectively, of the one-piece flexible immersion bag; 
         FIG. 12  is a partial cross section view showing engagement of the immersion bag system by the tip of the ultrasound probe; 
         FIG. 13 , an alternative embodiment, is an isometric view of an immersion bag system shown affixed to and in use with another form of the ultrasound probe; 
         FIG. 14  is a partially exploded view of the sterile immersion bag system incorporated to frictionally engage the lower nontapered portion of the ultrasound probe; 
         FIG. 15  is an exploded isometric top view of the immersion bag system shown distanced from the ultrasound probe; 
         FIG. 16  is an exploded isometric bottom view of the immersion bag system shown distanced from the ultrasound probe; 
         FIG. 17  is a cross section view of the one-piece flexible collar shown in  FIGS. 15 and 16  along line  17 - 17  of  FIG. 15  in order to show the general structure of the flexible collar; 
         FIG. 18  is a cross section view of the one-piece maneuvering ring along line  18 - 18  of  FIG. 15  in order to show the general structure of the maneuvering ring; 
         FIGS. 19 and 20  are top and bottom views respectively of the flexible collar including the flexible seal; 
         FIG. 21  is a partial cross section view showing engagement of the immersion bag system by the tip of the ultrasound probe; 
         FIG. 22  is a view like  FIG. 21  where sideways force is exerted upon the ultrasound probe thereby urging the ultrasound probe off center with respect to the flexible seal; and, 
         FIG. 23  is a top view in partial cross section along line  23 - 23  of  FIG. 22  showing the off-center location of the ultrasound probe and the gap created by the deforming of the annular sealing aspect of the probe/seal valve to open the probe/seal valve. 
     
    
    
     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: a flexible immersion bag  16 , a flexible collar  18  having an integral flexible seal  20 , and a capture ring  22  which can be rigid or semi-rigid, 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 also houses other internal components associated with operation of the transducer  26 . The upper region of the ultrasound probe body  24  includes suitable geometrically configured external structure about the upper region thereof. A control/power cable  28  exits from 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 sterile immersion bag system  10  incorporated to 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 flexible seal  20  integral to the flexible collar  18 , and the rigid or semi-rigid capture ring  22  collectively having features suitable for providing sealed communication of the immersion bag system  10  with respect to the lower portion, i.e., the body  24 , of the ultrasound probe  12 . 
     The flexible seal  20  which is integral to the flexible collar  18  is of a general annular shape each being fashioned of a flexible material, such as, but not limited to, foam, preferably close cell foam, latex, rubber, plastic, or other suitable flexible and pliable material, and includes aligned and connecting generally annular-shaped structure. Once engaged onto the ultrasound probe  12 , the flexible seal  20  is watertight permitting examinations in any position (e.g., patient sitting upright or laying down). 
     The immersion bag  16  is formed of a thin and flexible pliable acoustically invisible material (for example and demonstration, in a range of 0.1 micron to 250 microns), such as polyethylene, hydrophilic plastic, or other suitable material, which is capable of containing a gel or other suitable medium and 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 and/or bullet shaped and also includes an interior  32 . In the alternative, as shown in  FIG. 14 , an immersion bag  16   a  can have a conical shape for the greatest portion thereof and can include an end  30   a  which has an arcuate profile. 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 a general annular shape fashioned of a rigid or semi-rigid material, such as, but not limited to, plastic or other suitable material. 
       FIG. 3  is a cross section view of the one-piece flexible collar  18 , also shown in detail in  FIGS. 4 ,  5  and  6 . 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 flexible collar  18  and to show the structure of the valving extending through the wall thereof. The continuously formed flexible collar  18  is comprised of a plurality of geometrically configured and connecting 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  to intersect the flexible seal  20 , and the flexible seal  20  extending downwardly from the lower portion of the transition wall  40 . The lower portion of the flexible seal  20  is canted in slightly to ensure forcible flexed contact of the inner periphery of the flexible seal  20  with the body  24  of the ultrasound probe  12 . An arrangement and the relationship of the ultrasound probe  12  with the flexible seal  20  results in an annular shaped deformable probe/seal valve  49  which is formed as shown in  FIG. 6 , whereby such an arrangement and relationship is perfected by the engagement of the body  24  of the ultrasound probe  12  with the inner circumference of the flexible seal  20 . 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 through a middle opening  44  formed by the inner periphery of the flexible 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 flexible seal  20  through which an ultrasound probe body, such as the probe body  24 , can pass while still maintaining slideable engagement with the flexible seal  20 . 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 flexible collar  18  including the flexible seal  20 , the later of which when in intimate engagement with the body  24  of the ultrasound probe  12  cooperatively functions as a part of the probe/seal valve  49  itself. 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, gas, 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 purposes 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 holes or other suitable structure, are parted by the force of the expelled or displaced air, gas, liquid, aqueous mediums, gel, or the like, and modulate toward or to a closed state upon equalization between the interior  32  of the immersion bag  16  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 (typically, arcuate shaped noise above the examining surface). Such hydraulic force also provides resistance so that the ultrasound probe  12  does not come into direct contact with superficial structures, such as the delicate cornea of the eye. 
       FIG. 6  is a partial cross section view showing engagement of the immersion bag  16  by the tip of the ultrasound probe  12 . The immersion bag system  10  shown includes the flexible collar  18  including the flexible 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 , such as by the use of heat staking, tape, an O-ring, bands (not shown) which preferably are elastic, adhesive or other suitable attachment devices or methods. 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 flexible seal  20  flexes to sealingly accommodate and frictionally engage and seal against the body  24  of the ultrasound probe  12  forming the probe/seal valve  49 , as previously described. 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 end  30  of the immersion bag  16  to allow flexing of end  30  about the surface of the eye and to prevent contact of the transducer  26  with end  30  of the immersion bag 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 water, 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 . When examining ocular structures, coupling gel on the bag outer surface is not required. This is a unique feature of this invention. However, the use of gel on the bag exterior may be considered in cutaneous or industrial applications. Also, a foil sealed external container can hold an adequate amount of transducer coupling medium external to the immersion bag  16  for manual loading. During introduction of the end of the probe body  24  into the flexible collar  18  and the immersion bag  16 , the flexible seal  20  flexingly and transitionally seals against the body  24  of the ultrasound probe  12  and concurrently forms the probe/seal valve  49 . This ensures that the gel  60  or other aqueous medium is contained within the interior  32  of the immersion bag  16  and positive pressure is created. By exerting sideways force, using the ultrasound probe  12  against the flexible seal  20  or by rocking or angulating the ultrasound probe  12  against the flexible seal  20 , a gap is created by deforming the probe/seal valve  49  to expel excess internal pressure, air and liquid overfill allowing a reduction in immersion bag internal pressure to a desired level and a desired bag shape. 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 immersion bag  16  from bursting while still maintaining a suitable internal positive pressure within the immersion bag  16 . The ultrasound probe  12  is introduced a suitable distance (depending on probe transducer frequency) into the interior  32  of the immersion bag  16  filled 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 where the possibility of direct contact with structures under examination are minimized. The distal end of the invention, i.e., the immersion bag  16 , comes in direct contact with the cornea  56  or other superficial structure, and upon initial contact, the 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 inside enabling an ultrasound scan of suitable width across the anterior aspects of the eye or other superficial structure. An ultrasound scan across a noncentral portion of the eye  58 , such as the sclera or white of the eye or other superficial structure, can be accomplished, such as shown in  FIG. 8 , where the ultrasound probe  12  and the flexible collar  18  is unitarily repositioned off center and to the side of the immersion bag  16  while maintaining the central original 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, 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 flexible seal  20  will be pulled downwardly, whereby this action will open one or more of the self-sealing valves  50   a - 50   n . Concurrently, the flexible seal  20  can function as a deformed component of the probe/seal valve  49  by forcing the ultrasound probe  12  against the flexible seal  20  in one or another direction or by angulation or by rocking thereby deforming the probe/seal valve  49  and creating one or more gaps at the flexible seal. Thus, as the ultrasound probe  12  is moved into position as it is inserted into the immersion bag  16 , a slight pressure is maintained as the ultrasound probe  12  stops moving downwards, whereby excess filler gel/liquid or air has been simultaneously displaced. By angulating and/or forcing the body of the ultrasound probe  12  against one side of the probe/seal valve  49 , one or more gaps can be created (such as gap  122  shown in  FIGS. 22 and 23  of an alterative embodiment), thereby opening the probe/seal valve  49  to release internal pressure, trapped air and/or excess fluid. 
       FIG. 9  is a cross section view of a one-piece flexible collar  62  for use with an immersion bag system  10   a , an alternative embodiment, also shown in detail in  FIGS. 10 ,  11  and  12 . The flexible collar  62  is of a general annular shape fashioned preferably of a flexible material, such as foam, preferably close cell foam, latex, rubber or of other suitable flexible and pliable materials. 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 flexible collar  62  and to show the structure of the valving extending through the wall thereof. The continuously formed flexible collar  62  is comprised of a plurality of geometrically configured and connecting 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 inner wall  68  extending downwardly from the top wall  66 , and an angled transition wall  70  extending inwardly and downwardly from the lower portion of the inner wall  68  and a downwardly extending seal flexible  72  extending from the angled transition wall  70 . The lower portion of the flexible seal  72  can be canted in slightly to ensure forcible flexed contact of the inner periphery of the flexible 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 flexible 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 flexible 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 nonventing position, the shape of the self-sealing valves  80   a - 80   n  would assume a flattened position against the body  24  of the ultrasound probe  12 , but would modulate toward the open position during releasing of pressure or of fluid medium. 
       FIGS. 10 and 11  are top and bottom views, respectively, of the flexible collar  62 , including the flexible 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, gas, 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 purposes of illustration. In actual practice, the option of additional self-sealing valves  50   a - 50   n , which alternatively can be in the form of narrow gaps, slits or of related shape decreasing geometry structure or other suitable structure, are parted by the force of the expelled or displaced air, gas, liquid, aqueous mediums, gel, or the like, and modulate toward or to a closed state upon equalization between the interior  32  of the immersion bag  16  and ambient pressure. The self-sealing valves  80   a - 80   n  could 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  or optional/additional 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  80   a - 80   n  ensure adequate hydraulic force to remove wrinkles in the immersion bag  16  which result in acoustic artifacts (typically, arcuate shaped noise above the examining surface). Such hydraulic force also provides resistance so that the ultrasound probe  12  is prevented from coming into direct contact with the cornea of the eye. 
       FIG. 12  is a partial cross section view showing engagement of the immersion bag  16  by the tip of the ultrasound probe  12 . The immersion bag system  10   a  shown includes the flexible collar  62 , including the flexible 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 flexible seal  72  flexes to sealingly accommodate and frictionally engage and seal against the body  24  of the ultrasound probe  12  in the formation of the probe/seal valve  49   a . 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 end  30  of immersion bag  16  to allow flexing of the end  30  in a spaced relationship with the eye and to prevent contact of the transducer  26  with the end  30  of immersion bag  16  during such flexing. The mode of operation of this first alternative embodiment 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 . 
       FIG. 13  is an isometric view of an immersion bag system lob, an alternative embodiment, shown affixed to and in use with another form of the ultrasound probe  12 , herein designated as ultrasound probe  12   a . The lower region of the ultrasound probe  12   a  is sealed in close association with the following components comprising the immersion bag system lob each with flexible or semi-rigid qualities including: an immersion bag  16   a , a flexible collar  82  having an integral flexible seal  84 , and a capture ring  86  which can be rigid or semi-rigid having an annular groove  88  and an opening  89 , each of which are shown in  FIG. 14 . The lower region of the ultrasound probe  12   a  also closely associates with other components of the immersion bag system  10   a , including an O-ring  90 , preferably having flexible qualities, and a rigid maneuvering ring  92 , each of which are also shown in  FIG. 14 . The body  24   a  of the ultrasound probe  12   a  is, for the most part, a tapered tubular structure including tapered body section  24   b  and a nontapered body section  24   c , and includes a transducer  26   a  at one end and also houses other internal components associated with operation of the transducer  26   a . A control/power cable  28   a  exits from one end of the ultrasound probe  12   a  for connection to external support components associated with operation of the transducer  26   a.    
       FIG. 14  is a partially exploded view of the sterile immersion bag system  10   b  incorporated to frictionally engage the nontapered body section  24   c  of the ultrasound body  24   a  of the ultrasound probe  12   a . The structure of the immersion bag system  10   b  includes the immersion bag  16   a , the flexible collar  82 , the flexible seal  84  integral to the flexible collar  82 , the capture ring  86  which can be rigid or semi-rigid, the O-ring  90  and the maneuvering ring  92 , collectively, having features suitable for providing sealed communication and/or maneuvering of the immersion bag system  10   b  with respect to the lower portion, i.e., the nontapered body section  24   c  of the ultrasound probe  12   a.    
     The flexible seal  84 , which is integral to the flexible collar  82 , is of a general annular shape, each being fashioned of a flexible material, such as, but not limited to, foam, preferably close cell foam, latex, rubber, plastic, or other suitable flexible and pliable material, and includes aligned and connecting generally annular-shaped structure. Once engaged onto the nontapered body section  24   c  of the ultrasound probe  12   a , the flexible seal  84  is watertight permitting examinations in any position (e.g., patient sitting upright or laying down). 
     The immersion bag  16   a  is formed of a thin and flexible pliable acoustically invisible material (for example and demonstration, in a range of 0.1 micron to 250 microns), such as polyethylene, hydrophilic plastic or other suitable material which is capable of containing a gel or other suitable medium and which allows the passage of ultrasound waves. The immersion bag  16   a  preferably is substantially a conical shape for the greatest portion thereof and includes an end  30   a  which is arcuate in profile and also includes an interior  32   a . The top of the immersion bag  16   a  is reversed a short distance outwardly and about itself to form a lip  34   a  of annular shape extending about the upper region of the immersion bag  16   a  for accommodation of the capture ring  86 . The lip  34   a  is shown as it would subsequently appear when affixed over and around, and forced and depressed into the annular groove  88  of the capture ring  86  by the O-ring  90 , thereby forming an inwardly directed annular depression  93  thereabout, such as when securing the lip  34   a  of the immersion bag  16   a  to the capture ring  86 . A suitable size small band may be substituted for use in lieu of the O-ring  90 , whereby the band can be used to depress the lip  34   a  into the annular groove  88  of the capture ring  86  to form the annular depression  93 , or the band can be of greater vertical proportion to forcibly direct the broad portion of the lip  34   a  against outer periphery of the capture ring  86  to connect the lip  34   a  of the immersion bag  16   a  to the capture ring  86 . The O-ring  90  or the described bands and the capture ring  86  may also be used in the previously described embodiments to fasten the lip  34  of the immersion bag  16  to the capture ring  22 . The capture ring  86  is of a general annular shape fashioned of a rigid or semi-rigid material, such as, but not limited to, plastic or other suitable material. 
       FIG. 15  is an exploded isometric top view of the immersion bag system lob shown distanced from the ultrasound probe  12   a , and  FIG. 16  is an exploded isometric bottom view of the immersion bag system  10   b  shown distanced from the ultrasound probe  12   a.    
       FIG. 17  is a cross section view of the one-piece flexible collar  82 , also shown in  FIGS. 15 and 16 , taken along line  17 - 17  of  FIG. 15  in order to show the general structure of the flexible collar  82 . The continuously formed flexible collar  82  is comprised of a plurality of geometrically configured and connecting structures including a vertically oriented outer wall  94  having an externally located annular ring  96  which has a beveled profile forming the periphery of the flexible collar  82 , a horizontally oriented bottom wall  98  which is annular and which intersects the lower region of the outer wall  94  and extends inwardly a short distance, a horizontally oriented top wall  100  which intersects the upper region of the outer wall  94  and extends inwardly a short distance, an angled transition wall  102  extending inwardly and downwardly from the top wall  100  to intersect the flexible seal  84 , and the flexible seal  84  extending downwardly and inwardly from the lower portion of the transition wall  102 . The lower portion of the flexible seal  84  is canted in slightly to ensure forcible flexed contact of the inner periphery of the flexible seal  84  with the nontapered body section  24   c  of the ultrasound probe  12   a . An arrangement and relationship of the ultrasound probe  12   a  with the flexible seal  84  results in an annular shaped deformable probe/seal valve  49   b  which is formed as shown in  FIG. 21 , whereby such an arrangement and relationship is perfected by the engagement of the nontapered body section  24   c  of the body  24   a  of the ultrasound probe  12   a  with the inner circumference of the flexible seal  84 . Other annular regions are formed by the previously described structure of the flexible collar  82  including a top opening  104  bordered by the angled inner periphery of the transition wall  102  and a middle opening  106  bordered by the angled inner periphery of the flexible seal  84 , the combination of which serve as a guide structure for insertion of a probe body, such as the probe body  24   a , partially through the flexible collar  82 . A capture annulus  108  is formed by the junction of the inside surface of the outer wall  94 , the region underlying a portion of the top wall  100  and the inside surface of the bottom wall  98  for captured accommodation of the lip  34   a  of the immersion bag  16   a  and the capture ring  86  and O-ring  90 . An expansive bottom opening  110  is provided generally extending between and bounded by the lower to mid-region of the capture annulus  108  and the bottom edge of the flexible seal  84  through which a portion of the nontapered body section  24   c  of the ultrasound probe  12   a  can maintain slideable sealed engagement with the flexible seal  84 . One or more optional self-sealing valves  109  in tubular or cylindrical form or of other suitable structure are shown in dashed lines located along, about and extending through the transition wall  102  offering communication between ambient and the interior  32   a  of the immersion bag  16   a.    
       FIG. 18  is a cross section view of the one-piece maneuvering ring  92  along line  18 - 18  of  FIG. 15  in order to show the general structure of the maneuvering ring  92 . The maneuvering ring  92  frictionally engages over and about the combined structure of the flexible collar  82 , the O-ring  90 , the lip  34   a  of the immersion bag  16   a , the immersion bag  16   a , and the capture ring  86  as shown in  FIG. 21 . The use of the maneuvering ring  92  supplies a structure having a measured amount of rigidity in order that the user can grasp and position the immersion bag  16   b  with respect to the eye or other surface being examined without the danger of disturbing the integrity of the probe/seal valve  49   b . The interior geometry of the maneuvering ring  92  snappingly engages the exterior geometry of the flexible collar  82  in mutual coaxial engagement to secure about the capture ring  86 , the lip  34   a  of the immersion bag  16   a , and the O-ring  90 . The maneuvering ring  92  includes an annular outer wall  111 , a bottom wall  112  which intersects and extends inwardly a short distance from the bottom of the outer wall  111 , a top opening  114 , an annular receptor groove  116  adjacent the top opening  114  recessingly extending into the inner surface of the outer wall  111 , a middle opening  118  adjacent and below the receptor groove  116 , and a beveled bottom opening  120  located below and adjacent the middle opening  118  and between the inner edge of the bottom wall  112 . The receptor groove  116  of the maneuvering ring  92  snappingly engages the annular ring  96  extending from the flexible collar  82  as the flexible collar  82  gains entry through and into the structure of the maneuvering ring  92 , first by entering the top opening  114  followed by entry adjacent the annular receptor groove  116  and finally into the middle opening  118  where resistance to further positioning is subsequently offered by contact with the bottom wall  112 . 
       FIGS. 19 and 20  are top and bottom views, respectively, of the flexible collar  82 , including the flexible seal  84 . Also shown is one optional self-sealing valve  109  extending through the transition wall  102  of the flexible collar  82  and other annular structure of the flexible collar  82 . The use of one or more optional self-sealing valves  109  can be utilized to vent the interior  32   a  of the immersion bag  16   a  when the tip of the ultrasound probe  12   a  is introduced into the interior  32   a  of the immersion bag  16   a . Air, gas, liquids, gels, or other mediums or fluids can be displaced or vented through the optional self-sealing valve(s)  109  during introduction of the tip of the ultrasound probe  12   a  or during further operation of the invention. The size of the optional self-sealing valve(s)  109  is shown in exaggerated form for purposes of illustration. In actual practice, the choice of including optional self-sealing valve(s)  109  or of self-sealing valves  50   a - 50   n  which alternatively can be in the form of narrow gaps, slits or of related shape decreasing geometry structure or other suitable structure, are parted by the force of the expelled or displaced air, gas, liquid, aqueous mediums, gel, or the like, and modulate toward or to a closed state upon equalization between the interior  32   a  of the immersion bag  16   a  and ambient pressure. The self-sealing valve(s)  109  could be of different sized similar structure to operate across a pressure relief range. The purpose of the structure of the optional/additional self-sealing valve(s)  109  or optional/additional self-sealing valves  50   a - 50   n  is to prevent breakage of the immersion bag  16   a  by displacing air and to act as a fluid overflow. The optional self-sealing valve(s)  109  can ensure adequate hydraulic force to remove wrinkles, if any, in the immersion bag  16   a , which result in acoustic artifacts (typically, arcuate shaped noise above the examining surface). Such hydraulic force also provides resistance so that the ultrasound probe  12   a  is prevented from coming into direct or indirect contact with the cornea of the eye. 
       FIG. 21  is a partial cross section view showing engagement of the immersion bag  16   a  of the immersion bag system  10   b  by the tip of the ultrasound probe  12   a , i.e., the nontapered body section  24   c . The immersion bag system  10   b  shown includes the flexible collar  82 , including the flexible seal  84 , the capture ring  86 , and the immersion bag  16   a  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   a  and the juxtaposed upper portion of the immersion bag  16   a  within the capture annulus  108  by frictional engagement between the capture annulus  108  and the capture ring  86 . Other additional fixation and securing methods can be used in addition, such as, but not limited to, the use of heat staking, adhesive, or other suitable attachment. Additionally, the lip  34   a  of the immersion bag  16   a  is sealingly held between the inner surface of the outer wall  94  of the flexible collar  82  by the forced positioning of and by the forced engagement of the capture ring  86  against the lip  34   a  in cooperation with the spongy and elastic qualities of the flexible collar  82 . The flexible seal  84  flexes to sealingly accommodate and frictionally engage and seal against the nontapered body section  24   c  of the ultrasound probe  12   a  in the formation of the probe/seal valve  49   b . The tip of the ultrasound probe  12   a  is positioned within the interior  32   a  of the immersion bag  16   a , wherein the transducer  26   a  is spaced sufficiently from the end  30   a  of immersion bag  16   a  to allow flexing of the end  30   a  in a spaced relationship with the eye and to prevent contact of the transducer  26   a  with the end  30   a  of immersion bag  16   a  during such flexing. The mode of operation of this second alternative embodiment is substantially the same as described for the immersion bag system  10   a , the difference being that the flexible collar  82  is substituted for the flexible collar  62 , the shape of the immersion bag  16   a  is substantially conical with an arcuate end  30   a  and the maneuvering ring  92  is included. In this embodiment, the general shape of the immersion bag  16   a  is a combination of a conical shape terminating in an arcuate shape, whereby such a combination provides a minimum, i.e., not an excessive amount of material at the site of contact with the cornea, thereby minimizing bunching or folding of the immersion bag  16   a . The arcuate shape of the end  30   a  reverses upon contact with the cornea  56  to conformingly drape about the shape of the cornea in one-to-one correlation. Although the flexible collar  82  has been characterized as being an alternative to the flexible collars  18  and  62 , neither collar is to be construed as being preferred over the other—each have equal stature. 
       FIG. 22  is a view like  FIG. 21  where sideways force is exerted upon the ultrasound probe  12   a , thereby urging the ultrasound probe  12   a  off center with respect to the flexible seal  84  of the flexible collar  82  to create a gap  122  between the flexible seal  84  and the nontapered section  24   c  of the ultrasound probe  12   a , thus opening the probe/seal valve  49   b  to allow transfer of air or aqueous medium through the gap  122 . The geometry of the probe/seal valve  49   b  is influenced by this action to open the probe/seal valve  49   b . The geometry of the probe/seal valve  49   b  can be otherwise influenced by angulating or rocking the ultrasound probe  12   a  to cause deformation of and opening of the probe/seal valve  49   b  by creating other gap(s) to allow transfer of air or aqueous medium through such gap(s). The flexible qualities of the flexible seal  84  accommodate such movement of the ultrasound probe  12   a.    
       FIG. 23  is a top view in partial cross section along line  23 - 23  of  FIG. 22  showing the off-center location of the ultrasound probe  12   a  and the gap  122  created by the deforming of the annular sealing aspect of the probe/seal valve  49   b  to open the probe/seal valve  49   b . Gaps are also created in the previous embodiments in the same manner as just described with reference to  FIGS. 22 and 23 . 
     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 
           10   b  immersion bag system 
           12  ultrasound probe 
           12   a  ultrasound probe 
           16  immersion bag 
           16   a  immersion bag (conical) 
           18  flexible collar 
           20  flexible seal 
           22  capture ring 
           24  body 
           24   a  body 
           24   b  tapered body section 
           24   c  nontapered body section 
           26  transducer 
           26   a  transducer 
           28  control/power cable 
           28   a  control/power cable 
           30  end 
           30   a  end 
           32  interior 
           32   a  interior 
           34  lip 
           34   a  lip 
           36  outer wall 
           38  top wall 
           40  transition wall 
           42  top opening 
           44  middle opening 
           46  capture annulus 
           48  bottom opening 
           49  probe/seal valve 
           49   a  probe/seal valve 
           49   b  probe/seal valve 
           50   a - n  self-sealing valves 
           52  opening 
           54  slit 
           56  cornea 
           58  eye 
           60  gel 
           62  flexible collar 
           63  flexible seal 
           64  outer wall 
           66  top wall 
           68  inner wall 
           70  angled transition wall 
           72  flexible seal 
           74  top opening 
           76  bottom opening 
           78  capture annulus 
           80   a - n  self-sealing valves 
           82  flexible collar 
           84  flexible seal 
           86  capture ring 
           88  annular groove 
           89  opening 
           90  O-ring 
           92  maneuvering ring 
           93  annular depression 
           94  outer wall 
           96  annular ring 
           98  bottom wall 
           100  top wall 
           102  transition wall 
           104  top opening 
           106  middle opening 
           108  capture annulus 
           109  self sealing valve 
           110  bottom opening 
           111  outer wall 
           112  bottom wall 
           114  top opening 
           116  receptor groove 
           118  middle opening 
           120  bottom opening 
           122  gap