Patent Description:
Ultrasound transducers are commonly used in sterile environments yet it is impractical and expensive to keep the transducers and their accompanying signal cord sterile. Sterilization is time-consuming and not performed in the area where the ultrasound equipment is used. Because ultrasound transducers are expensive, maintaining sufficient numbers of available sterilized units is cost-prohibitive. Thus, common practice is to sheath the transducer and accompanying signal cord in a sterile sheath, with the outside of the sheath being sterile and the inside of the sheath being the only part that is in contact with the non-sterile transducer and cord. A number of patents have issued in this field, including: <CIT> (a sterile cover for a sonic probe); <CIT> (telescopingly-collapsed polymeric tube with open-ended polygonal body mounted inside the tube to keep entryway of tube open, polygonal body is flat prior to use and can be popped open); <CIT> (sterile cover for ultrasound transducer and connection cable); and <CIT>, <CIT> (sterile sheath for use in a biopsy system wherein biopsy needle pierces sheath). A collapsible device for single operator sheathing of an ultrasound probe is described in <NPL>.

This article discloses a two-part concept design consisting of a non-sterile probe holder and a sterile, disposable sheath cartridge that first snaps over the probe, thus protecting the outside of the sheath from contact with the probe. The probe can then be grasped through the sheath and pulled upwards, thus preventing contact of the gloved hands of the clinician with the non-sterile probe as the sheath unfurls along the length of the cord. The cartridge then opens to release the now sheathed probe. In a related field, a condom having deployment tabs is described in http://www. sensiscondoms.

Protek's Pull Up™ probe cover includes a pouch in form of a collar that is configured to snap open when squeezed with one hand, in order to facilitate pulling the cover over the probe and probe cable.

One of the problems that a user needs to be careful of when deploying the cover is not touching the non-sterile transducer cord when unfurling the cover. It is also difficult for an individual to apply a cover to a transducer probe by themselves without a high risk of contaminating the sterile field. Most prior art approaches require either two people or something physical to hold the ultrasound probe or the cover in place while applying and deploying the cover.

Further complicating the application of the sheath to the transducer is the fact that acoustic conductive gel must be applied to the transducer head before insertion into the sheath. It is difficult for the user to access the target surface for gel application and probe insertion with current fold methods, as the cover needs to be held open with a hand and the folded portion is not compact, causing the target surface to be several inches deep inside the cover. Keeping the gel, which is non-sterile, out of contact with the practitioner's hands, while also avoiding spreading the gel to other parts of the probe and the cord is a difficult task.

Thus, a need exists for a sheath and that can be easily applied to an ultrasound probe to achieve an easily repeatable process that maintains sterility of the outside of the sheath and the gloved hands of the practitioner who installs the sheath on the probe. The present invention addresses that need by providing three embodiments of a sheath that can be applied by one person easily and without risk of loss of sterility to the outside of the sheath.

One aspect of this invention is a ring sheath applicator with self-deploying elastic bands.

A second aspect of this invention is a semi-rigid sheath holder in which the flexible sheath is housed prior to use and from which it is dispensed.

The embodiment illustrated in figs. <NUM>-<NUM> is not covered by the subject-matter of the claims.

Referring now to the various figures wherein like reference characters refer to like parts there are described two embodiments of the invention, as well as a further embodiment that is outside the subject-matter of the claims.

With reference to <FIG> and <FIG>, in this first embodiment, the cover assembly consists of a sleeve-like sheath <NUM> closed on one end and open on the other end, a ring-shaped applicator <NUM>, and multiple elastic bands <NUM>. The sheath is made with traditional flexible ultrasound transducer probe cover materials and dimensions. As shown in <FIG>, the sheath <NUM> is folded accordion-style along its length to be retained on the outside of the rigid applicator ring <NUM>. The elastic bands <NUM> shown in <FIG> and <FIG>, are stretched around the outside of the sheath as it is placed onto the ring <NUM>. The elastic bands are placed at intervals from the closed-end to the open-end, and drawn together within the accordion fold, helping to retain the folded sheath onto the applicator ring.

With reference to <FIG> and <FIG>, to use the inventive sheath and ring installer, an applicator ring <NUM>, having an extended lip <NUM> is applied over an ultrasound transducer <NUM> by the user. Once the sheath is on the distal end of the transducer, the sheath-covered portion of the transducer can be grasped and the open end of the sheath pulled along the length of the transducer <NUM> and transducer cord <NUM> by holding the ring applicator and pulling away from the transducer thus causing the sheath to unfold and be transferred from the applicator to the transducer. As the sheath unfurls over the transducer, the elastic bands are transferred one-by-one to the transducer handle and cord, both releasing the sheath from the ring applicator and securing the sheath to the transducer in a form-fitting manner along its length. The ultrasound transducer and cord may be temporarily mounted on a stand that allows a practitioner wearing sterile clothing and gloves to apply the sheath without directly touching the transducer or cord.

When the full length of the sheath has been deployed, the applicator ring can be removed from the transducer cord by flexing the ring apart at break <NUM> and pulling the applicator free past the cord.

The ring applicator solves the problem of the difficulty for the user to access the target surface of the ultrasound transduce for gel application and probe insertion with current fold methods, as the cover needs to be held open with a hand and the folded portion is not compact, causing the target surface to be several inches deep inside the cover. The ring applicator holds the cover in a wide-open fashion and contains the folded portion in a neat and compact state, further improving the ability of a single person to apply the cover and maintain sterility, as well as improving the ease of access for gel application and probe insertion.

A second embodiment of an improved sheath for an ultrasound probe is shown in <FIG>. In this embodiment as shown in <FIG>, a semi-rigid dual-walled pouch <NUM> having two open ends <NUM>, <NUM> houses an accordion-pleated protective sheath <NUM> between the dual walls <NUM>, <NUM> of the pouch. The dual walls are clearly seen in <FIG>, which is a bottom end view of the dispenser flexed for use. In operation, the sheath is dispensed from the bottom end of the pouch as shown in <FIG>. The pouch can be made of cardboard or plastic or any other suitable material. The pouch is designed to house the sterile sheath and to snap open as shown in <FIG> and <FIG> when grabbed at the corners <NUM>, <NUM>, as shown in <FIG>. The protective sheath can be stuffed up inside the pouch as shown in <FIG> such that the pouch holds/encompasses or contains the sheath prior to use.

Assembly of an exemplary dual-walled pouch is as follows: An exemplary sheet is shown in <FIG>. The sheet of <FIG> is first folded between parts <NUM> and <NUM>, as shown in <FIG> such that parts <NUM> and <NUM> end up back-to-back. Next, parts <NUM> and <NUM> are folded to a <NUM> degree angle from their respective adjacent portions <NUM> and <NUM>, to form a base as shown in <FIG>, where parts <NUM> and <NUM> are vertical. The vertical parts of the pouch, <NUM> and <NUM> serve as guides onto which a protective sheath <NUM> is slid and pushed down to form accordion-like folds as shown in <FIG>. Once the entire sheath is pushed fully down onto parts <NUM> and <NUM> of the dispenser, parts <NUM> and <NUM> are folded up alongside parts <NUM> and <NUM> respectively to form outer walls of the dispenser. Lastly, parts <NUM> and <NUM> are wrapped around and affixed to part <NUM> to complete the pouch/sheath assembly. The completed pouch, without a sheath installed is shown in <FIG> and is shown with a sheath installed in <FIG> and <FIG>.

Advantages of the pouch design are that it uses a cost-efficient method of "folding" the cover to minimize its size. Next, the pouch provides a protective support to the cover which is beneficial in deployment of cover as well as handling the cover if deployment is performed by a single user. The cover is "folded" into a pouch type protective holder which is rigid enough to hold the cover in its "folded" configuration and makes it easier for the user to handle and use.

The method of folding the sheath into this pouch is very easy for manufacturing which makes it possible to consider for the extra cost of the pouch cover holder. The pouch also provides a printable area onto which a manufacturer's logo or use information can be printed, as shown, for example, in <FIG>.

Deployment of the exemplary sheath <NUM> out of the pouch <NUM> and over an ultrasound transducer <NUM> and cord <NUM> is shown in <FIG>.

A third embodiment of a protective sheath for ultrasound probes is shown in Figs. <NUM>-<NUM>. In Fig. <NUM>, the sheath <NUM> is a cylinder or other sleeve-like shaped container of flexible plastic or the like, having one open end <NUM> and one closed end <NUM>. The sheath is rolled tightly around a flexible band <NUM>, placing the folded portion in a compact state while leaving the closed end <NUM> that will go over the ultrasound probe fully accessible to the user. As shown in <FIG>, the sheath <NUM> is doubled over at the band, <NUM> such that the open end of the sheath <NUM> is substantially up to the closed end. This method of folding the cover is very fast and easy, and offers potential cost savings and excellent scalability for volume manufacturing.

<FIG> is a plan view of an exemplary cylindrical sheath having a longitudinal axis A and doubled over about its midsection at point B. The outer half of the length of the doubled over sheath is shown in full lines while the inner half of the length of the doubled over sheath is shown in hashed lines. The closed end of the sheath <NUM> is at the bottom of the two doubled over portions, as is the open end of the sheath, which in this view has a tab <NUM> attached for easy use as will be seen in the following explanation and figures. <FIG> shows the sheath of <FIG> with a flexible band <NUM> in cross section. <FIG> shows how the flexible band <NUM> shown in <FIG> is rolled down the length of the sheath, thus rolling up together both the inner and outer portions of the sheath. <FIG> shows a fully rolled sheath and a directional arrow pointing out the direction of insertion of an ultrasound probe.

In a preferred embodiment, shown in use <FIG>, one or more pull tabs <NUM> are attached to the open end of the rolled sheath and left exposed after the sheath is fully rolled for easy access.

As shown in <FIG> and <FIG>, a doubled over sheath <NUM> can also be rolled about itself without a band and can optionally include a pull tab <NUM> for easy deployment.

As shown in <FIG>, the user places the sheath over the ultrasound probe <NUM> holding the probe through the closed end of the sheath. The user then pulls the tab <NUM> causing the sheath to un-roll along the length of the transducer and cord <NUM>.

In an embodiment, the pull tab <NUM> can include a printed company logo, installation or expiry information.

In a further embodiment, shown in <FIG>, a band <NUM> is placed between the inner <NUM> and outer portions <NUM> of the folded sheath at the fold point <NUM>. In this embodiment, the sheath is rolled as described above and can be constructed with or without a pull tab <NUM>, as described above.

Claim 1:
A cover system for an ultrasound probe (<NUM>) having a distal end portion and a proximate end portion, the system comprising:
a cover formed of a flexible material in the shape of an elongated tubular sheath (<NUM>), said sheath having a longitudinal axis, an outer surface, a closed end and an open end, said open end being located at the opposite end of said sheath from said closed end,
a ring applicator (<NUM>), and
at least one elastic band (<NUM>),
said ring applicator having an oval or circular cylindrical shape, a perimeter, distal and proximate ends, and a single opening completely extending axially from said distal to said proximate end,
wherein said ring applicator further comprises a lip (<NUM>) that extends radially away from said proximal end of said cylinder to aid in retaining said sheath in place prior to installation onto the ultrasound probe and to further aid in deployment of the sheath,
said cover being applied over said ring applicator with said closed end of said cover being substantially flush with said distal end of said ring applicator, the majority of said tubular sheath being compressed along its longitudinal axis over said ring applicator with said elastic band placed about the outer surface of said cover to hold said cover onto said ring applicator.