Patent Publication Number: US-2005131301-A1

Title: Ultrasound probe receptacle

Description:
CROSS REFERENCE TO RELATED CASES  
      Applicants claim the benefit of Provisional Application Ser. No. 60/529,122, filed DEC. 12, 2003. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates generally to storing transducers used in ultrasonic imaging systems and, in particular, to the storage and maintenance of endocavity transducers, such as transesophageal echo (TEE) transducers.  
      2. Description of the Related Art  
      Ultrasonic imaging systems are used to observe the internal organs of a patient. The ultrasonic range is described essentially by its lower limit: 20 kHz, roughly the highest frequency a human can hear, although medical ultrasound imaging systems tend to use frequencies in the 2 to 15 MHz range. The systems emit ultrasonic pulses which, if not absorbed, echo (i.e., reflect), refract, or are scattered by structures in the body. Most of the received signal is from scattering, which is caused by many small inhomogeneities (much smaller than a wavelength) making a small part of the wave energy disperse in all directions. The signals are received and are translated into images by the ultrasound system.  
      A typical ultrasound system  100  is shown in  FIG. 1 , with each component labeled. The system  100  shown in  FIG. 1  is a SONOS 7500/5500 ultrasound system from Philips Electronics (Philips Ultrasound, Andover, Mass.). As can be seen in the drawings, ultrasound system  100  is mounted on four wheels  110  so that it can be relatively easily moved by a single person. These wheels can be locked in place by wheel lock  112  when sonography is being performed on a patient. The operator of the system uses keyboard  120  and touch panels  122  to control the operation of ultrasound system  100 , and can also use optical disk drive  132 , floppy disk drive  134 , or videocassette recorder (VCR)  136 , to store data and/or images from system  100 . A monitor  140  displays the ultrasound images.  
      The component which is placed on (or in) the patient in order to transmit and receive the ultrasonic waves which image the region of interest in the patient is called a “transducer”. In  FIG. 1 , several ultrasonic transducers  150  are shown being held by transducer holders  153  on the right-hand side of system  100 , next to monitor  140 . Although shown in the particular configuration of  FIG. 1 , it should be noted that transducer holders may take a variety of forms and may be located at a variety of places within and/or around the ultrasound system. In order to communicate data back to ultrasound system  100 , the various ultrasound transducers  150  are connected by a cable to transducer connections  155  on ultrasound system  100 .  
      Ultrasonic transducers take a variety of shapes and sizes, and each one is designed for one or more particular imaging applications. In general, transducers fit in one of two categories: those used externally (placed on the skin of the patient) and those used internally (placed inside the patient). External ultrasonic transducers, such as those used to perform imaging of a fetus during pregnancy, are familiar to most of the public. Internal ultrasonic transducers are less well-known, and include endocavity transducers (such as endorectal and endovaginal transducers) and intraoperative transducers (which are used during surgery to visualize internal structures).  
      One type of endocavity transducer is a transesophageal echo (TEE) transducer, such as the TEE transducer  200  shown in  FIG. 2 . The ultrasonic transducer probe  210  located at the distal end of TEE transducer  200  contains the transducer elements which transmit and receive the ultrasonic waves. Probe  210  is inserted into the patient&#39;s esophagus in order to scan internal organs, such as the heart, from its location inside the esophagus (thus having a vantage point which is not blocked by bone or other tissue). Deflection area  220  which connects probe  210  to flexible shaft  230  is capable of movement (i.e., “deflection”) relative to flexible shaft  230  so that TEE probe  210  can be aimed at the appropriate area. At the other end of flexible shaft  230  is probe handle  240  which contains the deflection controls for deflection area  220 . At its other end, probe handle  240  is connected to system connector cable  250  which is used to connect transducer  200  to system  100  by means of connector plug  260 . Connector plug  260  plugs into one of the transducer connections  155  in  FIG. 1 .  
      A TEE transducer  200 , with its probe  210  inserted inside a patient, can be seen in  FIG. 3 , which is based on  FIG. 8  of U.S. Pat. No. 6,572,547 to Miller et al., assigned to the same assignee as the present invention and hereby incorporated by reference. In  FIG. 3 , probe  210  is shown inside the esophagus  380  of a patient. Flexible shaft  230  leads from the deflection area  220  up through the esophagus  380  and the mouth  330  of the patient to probe handle  240  located outside of the patent&#39;s mouth  330 . The operator uses probe handle  240  to control the relative orientation of probe  210  inside the esophagus  380 . The flexible shaft  230  is inserted through introducer  335  which extends from the patient&#39;s lips back to the patient&#39;s uvula  333 .  
      In  FIG. 3 , introducer  335  protects the flexible shaft  230  from the patent and protects the patient from flexible shaft  230 . Although an introducer is shown in  FIG. 3  (and described in the &#39;547 patent), most ultrasound TEE examinations are performed without an introducer (except in special cases, such as infants). In most ultrasound TEE examinations, a bite guard is used to protect the transducer probe. It is true that operators may perform the TEE examination without a bite guard, but this is not recommended, as damage to the TEE transducer may result. Although seen in one location inside esophagus  380 , probe  210  can be inserted further into the patient, i.e., into the fundus of the stomach (see, e.g.,  FIG. 8C  of the &#39;547 patent). Ultrasonic transducer array  342  on probe  210  transmits and receives the ultrasonic waves as seen by the dotted lines in  FIG. 3 .  
      Although TEE transducer  200  in  FIGS. 2 and 3  resembles the Omniplane series of TEE transducers from Philips Electronics (Philips Ultrasound, Andover, Mass.), the TEE transducer  200  in  FIGS. 2 and 3  is intended only as an example of any endocavity transducers which may be used with any ultrasound system. Similarly, the ultrasound system in  FIG. 1  is intended to represent any ultrasound system which uses endocavity transducers.  
      Because, as graphically depicted by TEE transducer  200  in  FIG. 3 , endocavity transducers are inserted deeply into the bodies of patients, a protective disposable sheath is typically used to cover the endocavity transducer during an examination. Furthermore, endocavity transducers must be carefully maintained, cleaned, and disinfected between uses.  
      Exemplary transducer cleaning and maintenance operations are described in SONOS 7500/5500 TRANSDUCER REFERENCE GUIDE, Edition 7, published in December 2002 by Philips Electronics (Part No. M2424-99300-07; hereinafter referred to as “GUIDE”), hereby incorporated by reference. For example, as described therein, an endocavity transducer must be thoroughly washed, preferably with an enzymatic cleaner, and disinfected, preferably with a glutaraldehyde-based disinfectant, after each examination. After disinfecting the transducer for a period of time, it is thoroughly rinsed with sterile water and checked for any residual organic material. If any is found, the process is repeated (for full description, see, e.g., pages 2-14-2-15, GUIDE).  
      Although endocavity transducers could be stored like the external transducers  150  in  FIG. 1 , i.e., in holders  153  on the side of the ultrasound system  100 , this is not recommended for a number of reasons, some of which are obvious. First, storing endocavity transducers in such external holders is ill-advised because the surfaces of the endocavity transducer would be exposed to the environment, which may include direct sunlight and/or temperature extremes, as well as contaminants from the open air and accidental contact with other objects. Second, endocavity transducers must be stored separately from the other transducers in order to avoid any potential damage (see, e.g., page 2-4, GUIDE). Because of these dangers (and others), many operators will store endocavity transducers in their original case or in a drawer. However, this is also inappropriate, as there may be contamination if the transducer is stored in a slightly damp condition, and neither a typical drawer nor the original packaging for the transducer is designed for storing a cleaned and disinfected endocavity transducer until its next use.  
      As an example of the storage problems for endocavity transducers, consider a TEE transducer, such as the one described in reference to  FIGS. 2 and 3 . A new TEE transducer typically arrives in a carrying case, such as the one shown in  FIG. 4 . However, such a carrying case is inappropriate for the intermittent storage of a TEE transducer frequently used for examinations, at least because the case itself may become contaminated (cf. “Never store a TEE transducer in the carrying case, except to transport it”, emphasis in original, page 2-4, GUIDE). Because of the extensive cleaning and pre-reuse operations required by the TEE transducer, there is usually one or more designated areas for such operations in the hospital, clinic, or doctor&#39;s office. Typically, wall-mounted racks in the designated cleaning area end up serving as the storage area for TEE transducers between examinations.  
      However, these designated cleaning/disinfecting areas may be situated a considerable distance away from the location or locations where the ultrasonic transducers will be used to examine patients. For instance, in a typical mid-size hospital, the cleaning and disinfection area may be located in the basement, whereas the operating room (OR), intensive care unit (ICU), echo lab, radiology suites, or other places where endocavity ultrasound examinations are performed, may be located on the first, second, or third floor. Thus, in such a hospital, endocavity transducers will have to be transported to and from the examination area and the cleaning/disinfecting area, either with or without the rest of the ultrasound system. This naturally requires that the locations of the transducers be tracked, as well as their present disinfecting status, to ensure that each ultrasound system will have an appropriately matched disinfected transducer when an examination is about to be performed. Besides the extra work involved in such transportation and tracking, there is the risk of contamination whenever the transducers are moved from one place to another.  
      In addition to these problems, there may be particular storage or maintenance needs for particular transducers. For instance, the flexible shaft  230  of a TEE transducer  200  must not be bent or coiled into a circle of less than a certain diameter (typically around one foot) in order to avoid damaging the steering mechanism or shaft  230  itself. Furthermore, the distal end of the TEE transducer should be protected by a tip protector in order to prevent damage to the transducer array  342 .  
      Therefore, there is a need for a system and apparatus for the proper maintenance and storage of endocavity transducers used by ultrasound systems. Furthermore, it should be noted that, although the problems discussed above were brought up in the context of endocavity transducers in general, and in the context of TEE transducers in particular, the problems for which the present invention is a solution may be suffered by any ultrasonic transducer which belongs in the “critical” device category (devices which contact blood, compromise tissue, or are used in a sterile field) and/or “semi-critical” device category (devices which may come into contact with mucous membranes but do not penetrate a body surface).  
     SUMMARY OF THE INVENTION  
      One object of the present invention is to provide a receptacle appropriate for the storage, maintenance, and transportation of ultrasonic transducers used in critical or semi-critical environments.  
      Another object of the present invention is to provide an ultrasonic transducer receptacle which can be securably attached and detached from an ultrasound imaging system.  
      Yet another object of the present invention is to provide an ultrasonic transducer receptacle in which portions of the ultrasonic transducer only come into contact with a disposable liner.  
      Still another object of the present invention is to provide an ultrasonic transducer receptacle which has a visual means by which the present status, in terms of usage and/or cleaning/disinfecting, may be determined.  
      A further object of the present invention is to provide an ultrasonic transducer receptacle which is integrated into the physical structure of the ultrasound imaging system.  
      These and other objects are met by the present invention, a receptacle appropriate for the storage, maintenance, and transportation of ultrasonic transducers used in critical or semi-critical environments. In one aspect, the receptacle is embodied in a tray capable of being detachably secured to an ultrasound system, in which at least a portion of the ultrasonic transducer may be placed while being transported. In another aspect, the receptacle is embodied in a case which has a form-fitting cavity for holding the ultrasonic transducer, a movable or removable cover for sealing the transducer inside the case, and a handle to be used when the case is being transported.  
      A liner may be used to line the interior of the receptacle, thereby keeping the surfaces of the transducer separate from the interior surfaces of the receptacle. The liner may be disposable, semi-permanent, or permanent (depending on its ability to be cleaned and/or disinfected).  
      The movable/removable cover on the case may be transparent so that the operator can quickly determine the condition of the transducer contained within. Furthermore, a status indicator may be attached to the receptacle in order to provide the operator with information concerning the transducer.  
      Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      In the drawings:  
       FIG. 1  is a drawing of a conventional ultrasound imaging system;  
       FIG. 2  is a drawing of a conventional transesophageal echo (TEE) ultrasonic transducer for use with an ultrasound system such as ultrasound system  100  in  FIG. 1 ;  
       FIG. 3  is a diagram showing how the probe of a TEE transducer, such as TEE transducer  200  in  FIG. 2 , is inserted into the esophagus of a patient;  
       FIG. 4  is a photograph of a prior art carrying case for a TEE transducer, such as TEE transducer  200  in  FIG. 2 ;  
       FIG. 5  is a drawing of an ultrasound transducer receptacle according to a first presently preferred embodiment of the present invention; and  
       FIG. 6  is a drawing of an ultrasound transducer receptacle according to a second presently preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS  
      In general, the present invention is directed to a receptacle in which an ultrasonic transducer may be stored and transported, and which also provides appropriate sanitary safeguards for ultrasonic transducers used in critical or semi-critical environments. Two presently preferred embodiments are described herein: a tray which has a cavity for holding at least a portion of the ultrasonic transducer, and which is capable of being detachably secured to the ultrasound system, according to a first preferred embodiment; and a case which has a form-fitting cavity for holding the ultrasonic transducer, and which has a handle and a movable or removable cover, through or by which the operator may determine the current status of the ultrasonic transducer. These presently preferred embodiments, the tray and the case, are only two examples within the wide variety of embodiments possible in accordance with the present invention. In other words, the scope of the present invention includes embodiments which share one or more features of both the presently preferred embodiments, and embodiments which share one or more features with only one of the presently preferred embodiments.  
      In the first presently preferred embodiment, the inventive receptacle takes the form of tray  500 , as shown in  FIG. 5 . For convenience, only certain portions of the overall ultrasound imaging system are shown in  FIG. 5 . The portions of the ultrasound system shown in  FIG. 5  include a pedestal  410  and an articulating monitor arm  420  which holds the system&#39;s monitor (not shown in  FIG. 5 ) and enables the operator to move the monitor into an appropriate position. Portions of transducer probe  200  can also be seen in  FIG. 5 , including probe handle  240 , which is set into probe handle holder  411  on pedestal  410 , and probe  210 , which is resting in a portion of tray  500 .  
      As can be seen in  FIG. 5 , tray  500  is constructed to complement the architecture of the area to which it is attached. For example, the profile of tray  500  in the horizontal plane is roughly in the shape of an upside-down “U” in order that tray  500  may fit atop pedestal  410  yet still fit around the base  421  of monitor arm  420 . In this manner, the shape of tray  500  complements the overall structure of the ultrasound system, and does not protrude from either side of the ultrasound system, nor above the monitor. Because of its complementary shape, tray  500  will not obstruct a technician&#39;s view when moving the entire ultrasound system, nor is tray  500  likely to catch on a doorway or other object while the entire ultrasound system is being moved. It should be noted that tray  500  is only one example of complementarity according to the present inventive receptacle. In other words, the manner in which another receptacle may complement another ultrasound system may be completely different, depending on the specific shape of the other ultrasound system. Furthermore, a receptacle according to the present invention does not have to be resting on a planar surface of the ultrasound system (as tray  500  is resting on pedestal  410 ), but may rather be contained within a portion of the ultrasound system, for example, or be attached to a side of the ultrasound system.  
      Tray  500  is constructed of a material which is capable of being cleaned, disinfected, and/or sterilized (thereby making tray  500  reusable). However, in other embodiments of the present invention, it is possible for the receptacle to be constructed from a material which is disposable, i.e., an embodiment where the receptacle itself is disposable or semi-permanent. Tray  500  preferably weighs less than a maximum of about  10  pounds when empty.  
      Tray  500  is removably attached to pedestal  410 . In  FIG. 5 , the means of removable attachment comprise portions on the bottom of tray  500  which engage portions on the top of pedestal  410  when tray  500  is moved and locked into place. The removable attachment means may comprise one or more protrusions formed on the top surface of pedestal which fit into one or more matching receiving means, such as tracks, on the bottom surface of tray  500 . In other embodiments, the removable attachment means may comprise any form of mechanical means, including, but not limited to, one or more snaps, one or more latches, a notch and detent system, or a system of mounting brackets. In any of these embodiments, the attachment means is intended to keep tray  500  secure enough so that tray  500  will not be dislodged by the typical movements of the entire ultrasound system when it is being moved from place to place.  
      In  FIG. 5 , the probe  210  at the distal end of transducer  200  is sitting in a portion of tray  500 . Probe  210  is held in place by clip  510  in order to prevent probe  210  from falling out of tray  500 . As shown in  FIG. 5 , clip  510  may be used to hold any portion of probe  210 , as long as the sensitive portions of probe  210 , such as transducer array  342 , are adequately protected. A protective tip may cover probe  210  while probe  210  is clipped into tray  500 . Probe  210  may be covered and clipped to tray  500  immediately after being disinfected.  
      The tray embodiment shown in  FIG. 5  can be used for carrying portions or the entirety of transducer  200  to and from a cleaning/disinfecting area. For example, after an examination, probe  210  and flexible shaft  230  may be disconnected from probe handle  240  and placed in tray  500 , which is then detached from pedestal  410  and brought to the cleaning/disinfecting area. It may be desireable to separate these portions from the remaining portions of the transducer  200  because probe  210  and flexible shaft  230  need a higher level of disinfection than probe handle  240  or connector cable  250  because probe  210  and flexible shaft  230  were inserted into the patient&#39;s body. Typically, probe  210  and flexible shaft  230  have to be immersed in a glutaraldehyde solution, whereas the probe handle  240  and connector cable  250  need only be cleaned with soap and water (and may, in fact, be damaged if immersed in the glutaraldehyde solution).  
      Preferably, the entire transducer  200  is placed in tray  500  for transport to the cleaning/disinfecting area, where all the component parts of transducer  200  are appropriately cleaned and disinfected. When tray  500  is holding the entire transducer, probe handle  240  is held in portion  520  across from where probe  210  is clipped, and flexible shaft  230  juts out from tray  500 . Specifically, shaft  340  runs out from probe  210  at trap lip  532  and re-enters tray  500  so that the portion entering probe handle  240  rests on at tray lip  534 . Of course, other embodiments may wish to avoid having any portion of the transducer hanging out of tray  500 . The remaining portions of transducer  200 , connector cable  250  and connector plug  260  (not shown in  FIG. 5 ), are placed in section  540  of tray  500 . After being cleaned, disinfected, and appropriately dried, transducer  200  may be stored in tray  500 , and await its next use. Tray  500  may also be used to carry other ultrasound system accessories, such as the mouth guard and ECG pads.  
      In order to clarify the cleaning/disinfecting status of the transducer  200  lying in tray  500 , a status indicator may be used to indicate whether it is currently ready to be used, whether it has just been used, or whether it has been in storage, and for how long (as it may require another cycle of cleaning/disinfecting before use). Systems of status identification according to the present invention will be described in greater detail in reference to the second preferred embodiment, described below with reference to  FIG. 6 .  
      In the first preferred embodiment of the present invention, as shown in  FIG. 5 , a disposable liner may be used to line the inside of tray  500  before transducer  200  is placed back into tray  500  after a cleaning/disinfecting. Preferably, this is done after each cleaning/disinfecting procedure. After each examination, the disposable liner is left in place until tray  500  arrives at the cleaning/disinfecting area, where it is removed and either cleaned/disinfected or thrown out. In other embodiments, the liner may be permanent or semi-permanent, with the intention that the liner be cleaned/disinfected after each examination. Furthermore, a removable cover may be locked onto the top of tray  500  after each cleaning/disinfecting in order to ensure that the transducer remains relatively clean while being stored. Movable and removable covers according to the present invention will be described in greater detail in reference to the second preferred embodiment, described below with reference to  FIG. 6 . In the case of tray  500 , such a cover might comprise a clear plastic material which is spread over the top of tray  500  in order to seal in transducer  200 . The plastic seal remains intact until the next time the transducer is used, when it is removed and thrown out.  
      In the second presently preferred embodiment, the inventive receptacle takes the form of a case  600 , as shown in  FIG. 6 . The case in  FIG. 6  has roughly the same profile as the tray in  FIG. 5 , but also includes a cover (not shown in  FIG. 6 ), and a handle  610  which can be used to hold case  600  when transporting the transducer separately from the rest of the ultrasound imaging system. The cover is either removable or movable (i.e., capable of both sealing in the contents of case  600  and moving out of the way so that the operator may access the contents). Examples of movable covers include, but are not limited to, covers connected to case  600  by hinges, covers which lock onto, snap onto, slide onto, or form another type of friction seal with case  600 , and covers which are sealed onto case  600  by a vacuum seal.  
      Preferably, the cover of case  600  is substantially transparent so that the operator may easily observe the transducer contained therein in order to determine general status and/or level of contamination of the transducer. In addition, a status indicator may be incorporated into the cover or into another part of case  600 . The status indicator would provide information to anyone viewing the outside of case  600  as to the transducer stored within. Such information may include, for example, the state of disinfection and/or cleaning, the appropriate routing for the transducer, the owner of the transducer, the safety test status of the transducer, the repair status of the transducer, or any other information of importance concerning the transducer.  
      The status indicator may be implemented, for example, by lettering, symbols, and/or color codes on a designated rewritable surface located on the transparent cover. As another example, a system of status indication could be used in which removable labels (with lettering, symbols, and/or color codes) are placed on, and removed from, the cover after specified acts, events, or periods of time. The status indicator could also be implemented by mechanical means (such as movable tabs in slots) or electronic means (such as an LED or LCD display with appropriate controls) attached to the cover of case  600 . Other embodiments of the present invention may locate the status indicator on a different surface of case  600 , or may implement the status indicator by another means.  
      The interior  620  of case  600  has a form-fitting cavity for the transducer. The form-fitting cavity would be similar in shape to the cavity shown in the prior art case of  FIG. 4  and may be constructed of, for example, foam or plastic. Similar to tray  500 , the form-fitting cavity of case  600  may have a liner for keeping the form-fitting cavity and/or the transducer clean and disinfected, and the liner may be disposable, permanent, or semi-permanent. The outside surface  630  of case  600  may be constructed of either hard material or soft material, which may depend on the material used for the form-fitting cavity in the interior  620  of case  600 .  
      While there have shown and described and pointed out fundamental novel features of the invention as applied to two preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.