Patent Description:
Ultrasound transducers are commonly used in clean, but non-sterile environments, such as patient examination rooms. In many typical ultrasound procedures, such as prenatal abdominal ultrasounds, bladder or other organ screenings, transesophageal echocardiography, etc., an acoustic ultrasound gel is applied to a supine patient's abdomen and an ultrasound transducer is positioned to contact the gel and is moved around the abdomen to acquire ultrasound images. Once the procedure is complete, both the patient and the ultrasound transducer must be cleaned of gel. In circumstances in which time between procedures is a concern, the cleaning process negatively impacts productivity. Examples of known removable interfaces for covering ultrasound transducers are disclosed in Documents <CIT> , <CIT> , <CIT>.

The following detailed description refers to the accompanying drawings.

The present invention provides an ultrasound transducer interface pad, comprising: a first substrate layer (<NUM>) having a first surface and a second surface; a hydrophilic layer (<NUM>) formed on the first surface of the first substrate layer, wherein the hydrophilic layer is configured to be hydrated to provide an acoustic coupling between an ultrasound transducer and a patient; a second substrate layer (<NUM>) having a third surface and a fourth surface; a first adhesive layer (<NUM>) formed on the third surface of the second substrate layer and configured to adhere to the second surface of the first substrate layer; and a second adhesive layer (<NUM>) formed on the fourth surface of the second substrate layer and configured to adhere to an operational portion of an ultrasound transducer characterized in that: the first adhesive layer comprises a non-silicon-based adhesive including an acrylic rubber-based adhesive material or a synthetic rubber-based adhesive material and the second adhesive layer comprises a silicone-based adhesive, and wherein the non-silicone-based adhesive exhibits a first removal force greater than a second removal force of the silicone-based adhesive.

In a further aspect, the present invention provides a method of making a disposable ultrasound transducer interface pad, the method comprising: applying a hydrophilic material to a first surface of a first substrate layer (<NUM>) to form a hydrophilic layer (<NUM>), wherein the hydrophilic material is configured to be hydrated to provide an acoustic coupling between the patient and an ultrasound transducer; curing the hydrophilic layer; applying a first adhesive to a third surface of a second substrate layer (<NUM>) to form a first adhesive layer (<NUM>), applying a second adhesive to a fourth surface of the second substrate layer to form a second adhesive layer (<NUM>); bonding the first substrate layer to the second substrate layer via the first adhesive layer; and cutting the bonded first substrate layer and second substrate layer to a size and a shape to form the disposable ultrasound transducer interface pad, wherein the first adhesive layer comprises a non-silicone-based adhesive and the second adhesive layer comprises a silicone-based adhesive, and wherein the non-silicone-based adhesive exhibits a first removal force greater than a second removal force of the silicone-based adhesive.

Implementations described herein relate to materials for providing an effective and easy to use interface between an ultrasound transducer and a patient. Consistent with one implementation described herein, a disposable transducer interface includes a multilayer configuration, hereinafter referred to as a "pad," for engaging an operating end of the transducer on one side and a patient's skin on the opposite side. The disclosed multilayer interface pad includes a carrier layer, with an adhesive layer and a hydrophilic layer applied to opposing sides of the carrier layer. During use, the adhesive layer side of the pad removably adheres to the transducer (or patient) to provide a positive, consistent coupling between the pad and the transducer. The hydrophilic layer is then hydrated to provide a positive acoustic coupling that facilitates clear and efficient transmission of ultrasound signals therethrough and eliminates the need to use traditional acoustic coupling gel.

<FIG> illustrate an environment <NUM> in which embodiments described herein may be implemented. As shown in <FIG>, environment <NUM> includes a patient <NUM>, an ultrasound transducer <NUM>, and an interface pad <NUM>. During use, as shown in <FIG>, interface pad <NUM> may be used in one of two manners. In a first embodiment, as shown in <FIG>, interface pad <NUM> may be adhered, as described below, to the operational end of ultrasound transducer <NUM>, while in the second embodiment, as shown in <FIG>, interface pad <NUM> may be adhered to patient <NUM>. In either embodiment, once affixed to either transducer <NUM> or patient <NUM>, pad <NUM> may be hydrated by applying a liquid, such as water, saline, lidocaine, chloraprep, isopropyl alcohol, or other like solution to the exposed surface to form an acoustically efficient interface and allow for easy movement (i.e., sliding) between transducer <NUM> and interface pad <NUM>. In some embodiments, a patient's bodily fluid or excretions may be sufficient to hydrate pad <NUM>. In such embodiments, external or added hydrating solutions may not be necessary.

<FIG> illustrate cross-sectional views of exemplary implementations of interface pad <NUM>, depicted as interface pads <NUM>-<NUM> to <NUM>-<NUM>, respectively. As shown in <FIG>, interface pad <NUM>-<NUM> includes a substrate layer <NUM>, such as a polyurethane carrier or material having a thickness ranging from approximately <NUM> to <NUM>. Consistent with implementations described herein, substrate layer <NUM> may be formed in either a planar or non-planar (e.g., shaped) configuration depending on application. For example, in some embodiments, substrate layer <NUM> may have a shaped (e.g., three-dimensional) configuration corresponding to the ultrasound transducer onto which it is to be applied. In other embodiments, substrate layer <NUM> may be formed as a planar layer usable with a number of different transducers and in a variety of procedures. Furthermore, consistent with embodiments described here, substrate layer <NUM> may be formed in any feasible manner to accomplish the desired dimensions. For example, substrate layer <NUM> may be formed by extrusion, dipping, molding, chemical deposition, etc..

Consistent with embodiments described herein, interface pad <NUM>-<NUM> further includes a hydrophilic coating layer <NUM> applied to one side of substrate layer <NUM>. In this configuration, hydrophilic coating layer <NUM> is provided on an outside of interface pad <NUM> relative to transducer <NUM>.

In one embodiment, hydrophilic coating layer <NUM> includes an ultra-violet (UV) light or heat curable materials, such as polyvinylpyrrolidone/polyurethane (PVP/PU) or poly methacrylate (PM), having a thickness in the range of approximately <NUM> to <NUM> microns. During manufacture, hydrophilic coating layer <NUM> may be applied to the substrate layer <NUM> and cured via exposure to UV light or exposing the layer to heat.

During use, an acoustic coupling gel may be applied to an inside of substrate layer <NUM> prior to applying interface pad <NUM>-<NUM> to the ultrasound probe. Next, hydrophilic coating layer <NUM> may be activated using only water or saline to provide the requisite acoustic coupling interface between transducer <NUM> and patient <NUM>.

Consistent with embodiments described herein, interface pad <NUM>-<NUM> may be formed of any suitable shape or dimensions consistent with the particular ultrasound transducer or patient body part with which it is to be used. For example, in one embodiment, interface pad <NUM>-<NUM> may be formed in a rectangular configuration having a length of approximately <NUM> inches and a width of approximately <NUM> inches.

<FIG> illustrates an embodiment of interface pad <NUM>-<NUM> that includes a second hydrophilic coating layer <NUM> applied on a side of substrate layer <NUM> opposite from hydrophilic coating layer <NUM>. During use, hydrophilic coating layers <NUM> and <NUM> may each be activated using only water or saline to provide the requisite acoustic coupling interface between transducer <NUM> and patient <NUM>.

In another implementation, as shown in <FIG>, interface pad <NUM>-<NUM> includes substrate layer <NUM>, an adhesive layer <NUM>, a hydrophilic coating layer <NUM>, and a removable release layer <NUM>. In one embodiment, substrate layer <NUM> comprises a polyurethane film carrier or material, such as polyether polyurethane having a thickness ranging from approximately <NUM> to <NUM> millimeters (mm).

In other embodiments, adhesive layer <NUM> may include an acrylic or synthetic rubber-based adhesive material. Such non-silicone-based adhesives, may exhibit significantly higher removal forces (e.g., as high as <NUM>. 7N per <NUM>). An adhesive having a higher removal force may be desirable in some circumstances, such as where slippage of the pad during use is a concern.

Consistent with embodiments described herein, adhesive layer <NUM> is applied (e.g., coated) onto substrate layer <NUM> at a coat weight ranging from approximately <NUM> to <NUM> grams per square meter (gsm), and preferably at a coat weight of <NUM> gsm, resulting in adhesive layer <NUM> having an applied thickness ranging from <NUM> to <NUM> (e.g., <NUM>).

As shown in <FIG>, hydrophilic coating layer <NUM> is applied to substrate layer <NUM> on an opposite side of substrate layer <NUM> relative to adhesive layer <NUM>. During manufacture and prior to use, interface pad <NUM>-<NUM> includes a release layer <NUM> (also referred to as a liner or release liner) that is provided on adhesive layer <NUM> to protect the tackiness of adhesive layer <NUM> and to prevent adhesive layer <NUM> from adhering to other items or itself prior to use. In one implementation, release layer <NUM> comprises a polycarbonate layer. Consistent with embodiments described herein, release layer <NUM> is removed (e.g., peeled off) prior to using interface pad <NUM>-<NUM>, e.g., prior to adhering interface pad <NUM> to transducer <NUM>/patient <NUM>. In some embodiments, release layer <NUM> may include an edge area or slit that allows release layer <NUM> to be easily removed when interface pad <NUM>-<NUM> is ready for use.

Although interface pad <NUM>-<NUM> of <FIG> is described above as including three distinct layers <NUM>-<NUM> and a release layer <NUM>, in other implementations, interface pad <NUM> may be formed of only two layers, with an adhesive layer <NUM> being applied directly to hydrophilic coating layer <NUM>, without the requirement of an underlying polyurethane substrate layer.

<FIG> depicts interface pad <NUM>-<NUM> that includes substrate layer <NUM> and hydrophilic layer <NUM>, as described above in relation to <FIG>. In addition, interface pad <NUM>-<NUM> includes a second substrate layer <NUM> sandwiched between adhesive layer <NUM> and a second adhesive layer <NUM>. In some implementations, this combination of adhesive layer <NUM>, second substrate layer <NUM>, and second adhesive layer <NUM> is formed independently of substrate layer <NUM> and hydrophilic coating layer <NUM>. During manufacture, adhesive layer <NUM> (previously joined with second substrate <NUM> and second adhesive layer <NUM>) is joined with initial substrate <NUM>, the opposite side of which includes hydrophilic coating layer <NUM>.

In one embodiment, second substrate layer <NUM> and initial substrate layer <NUM> each comprises a polyurethane film carrier or material, such as polyether polyurethane having a thickness ranging from approximately <NUM> to <NUM> millimeters (mm). In some implementations, adhesive layers <NUM>/<NUM> may include a silicone-based adhesive, having, for example, an adhesion (or removal force) of between <NUM> and <NUM> Newtons (N) per <NUM> millimeters (mm). The relatively low removal force of such a silicon-based adhesive renders interface pad <NUM>-<NUM> generally repositionable after initial deployment. Furthermore, such silicone-based adhesives are capable of sticking to itself without destroying the product during initial deployment, repositioning or removing.

Adhesive layer <NUM> include an acrylic or synthetic rubber-based adhesive material. The non-silicone-based adhesives exhibit significantly higher removal forces (e.g., as high as <NUM>. 7N per <NUM>). An adhesive having a higher removal force may be desirable in some circumstances, such as where slippage of the pad during use is a concern.

Thus, adhesive layer <NUM> include a different material than adhesive layer <NUM>, i.e. adhesive layer <NUM> include an acrylic or synthetic rubber-based adhesive material and adhesive layer <NUM> include silicone-based adhesive.

Consistent with embodiments described herein, adhesive layers <NUM>/<NUM> are applied (e.g., coated) onto second substrate layer <NUM> at a coat weight ranging from approximately <NUM> to <NUM> grams per square meter (gsm), and preferably at a coat weight of <NUM> gsm, resulting in adhesive layers <NUM>/<NUM> each having an applied thickness ranging from <NUM> to <NUM> (e.g., <NUM>).

During manufacture and prior to use, interface pad <NUM>-<NUM> also includes release layer <NUM> (also referred to as a liner or release liner) that is provided on second adhesive layer <NUM> to protect the tackiness of second adhesive layer <NUM> and to prevent second adhesive layer <NUM> from adhering to other items or itself prior to use. In one implementation, release layer <NUM> comprises a polycarbonate layer. Consistent with embodiments described herein, release layer <NUM> is removed (e.g., peeled off) prior to using interface pad <NUM>, e.g., prior to adhering interface pad <NUM>-<NUM> to transducer <NUM>/patient <NUM>. In some embodiments, release layer <NUM> may include an edge area or slit that allows release layer <NUM> to be easily removed when interface pad <NUM> is ready for use.

In other implementations, although not depicted in <FIG>, a second release layer may be applied to a surface of adhesive layer <NUM> opposite to second substrate <NUM> prior to application of adhesive layer <NUM> to initial substrate <NUM>. In this manner, the adhesive layer <NUM>/second substrate <NUM>/second adhesive layer <NUM> combination may be protectively stored prior to use.

<FIG> illustrate flow charts illustrating exemplary processes <NUM>, <NUM>, and <NUM>, and <NUM>, respectively of forming and using an ultrasound transducer interface pad in accordance with embodiments described herein, with process <NUM> corresponding to the embodiment of <FIG>, process <NUM> corresponding to the embodiment of <FIG>, process <NUM> corresponding to the embodiment of <FIG>, and process <NUM> corresponding to the embodiment of <FIG>.

Referring to <FIG>, a hydrophilic material may be coated onto one side of a substrate material (block <NUM>). For example, hydrophilic layer <NUM> may be coated (e.g., sprayed, brushed, etc.) on a side of a sheet of polyurethane substrate. As described above, as a precursor to the application of hydrophilic layer <NUM>, the substrate material (e.g., substrate layer <NUM>) may be initially formed into a desired configuration using a suitable manufacturing technique, such as extrusion, dipping, molding, deposition, etc..

At block <NUM>, the hydrophilic material is cured, such as via heat or UV light. At block <NUM>, one or more interface pads <NUM> are cut to a desired size and/or shape, such as with a die cut machine.

At block <NUM>, a traditional ultrasound coupling gel is applied to an inside surface of an interface pad <NUM>-<NUM>. Next, interface pad <NUM>-<NUM> is applied to an operating end of ultrasound transducer <NUM> to secure interface pad <NUM>-<NUM> to transducer <NUM> (block <NUM>). Next, the hydrophilic layer is activated (block <NUM>). For example, a water or saline may be applied to hydrophilic layer <NUM>. Finally, the ultrasound transducer with the activated interface pad secured thereto is applied to a region of interest on a patient (block <NUM>).

Referring to <FIG>, a hydrophilic material may be coated onto both sides of a substrate material (block <NUM>). For example, hydrophilic layers <NUM> and <NUM> may be coated (e.g., sprayed, brushed, etc.) onto the sides of a sheet of polyurethane substrate. At block <NUM>, the hydrophilic material is cured, such as via heat or UV light. In some implementations, hydrophilic layer application and curing are done independently for each of layers <NUM> and <NUM>. At block <NUM>, one or more interface pads <NUM>-<NUM> are cut to a desired size and/or shape, such as with a die cut machine.

At block <NUM>, one of the hydrophilic layers is activated. For example, hydrophilic layer <NUM> is activated using water or saline. Next, interface pad <NUM>-<NUM> is applied to an operating end of ultrasound transducer <NUM> to secure interface pad <NUM>-<NUM> to transducer <NUM> via the activated hydrophilic layer <NUM> (block <NUM>). Next, the other hydrophilic layer is activated (block <NUM>). For example, a water or saline may be applied to hydrophilic layer <NUM>. Finally, the ultrasound transducer with the activated interface pad secured thereto is applied to a region of interest on a patient (block <NUM>).

Referring to <FIG>, an adhesive layer is initially applied to a substrate layer (block <NUM>). For example, a silicone adhesive material may be coated (e.g., poured, sprayed, brushed, etc.) onto a first surface of a polyurethane substrate layer, such as substrate layer <NUM> to form the adhesive layer. Next, a release layer, such as a polymeric or paper layer, may be applied to the adhesive layer to prevent the adhesive from losing tackiness or sticking to unintended materials (block <NUM>). For example, release layer <NUM> may be applied to a tacky side of adhesive layer <NUM>.

Next, a hydrophilic material may be coated on a reverse side of the substrate layer (block <NUM>). For example, hydrophilic layer <NUM> may be coated (e.g., poured, sprayed, brushed, etc.) on a side of substrate <NUM> opposite to adhesive layer <NUM>. At block <NUM>, the hydrophilic material is cured, such as via heat or UV light. At block <NUM>, one or more interface pads <NUM>-<NUM> are cut to a desired size and/or shape from the layered materials, such as with a die cut machine.

At block <NUM>, the release layer is removed, and the adhesive layer is applied to either to an operating end of an ultrasound transducer or directly to the region of interest on the patient. For example, release layer <NUM> is removed to expose the tacky side of adhesive layer <NUM> and the adhesive layer <NUM> is then applied to transducer <NUM> or patient <NUM>. Next, at block <NUM>, the hydrophilic layer is activated. For example, hydrophilic layer <NUM> is activated using water or saline. Finally, either the ultrasound transducer with the activated interface pad <NUM>-<NUM> secured thereto is applied to a region of interest on a patient or the ultrasound transducer is applied to the activated interface pad <NUM>-<NUM> secured to the patient (block <NUM>).

Referring to <FIG>, a two-sided adhesive is formed and/or sourced (block <NUM>). For example, a material having second substrate <NUM>, sandwiched between adhesive layer <NUM> and second adhesive layer <NUM> is formed. One or more release layers, such as a polymeric or paper layer, may be applied to the adhesive layers <NUM>/<NUM> to prevent the adhesive from losing tackiness or sticking to unintended materials (block <NUM>).

Next, a hydrophilic material may be coated on a reverse side of the substrate layer (block <NUM>). For example, hydrophilic layer <NUM> may be coated (e.g., poured, sprayed, brushed, etc.) one side of substrate <NUM>. At block <NUM>, the hydrophilic material is cured, such as via heat or UV light. At block <NUM>, the two-sided adhesive of blocks <NUM>/<NUM> is bonded to the side of the substrate layer opposite the hydrophilic layer. Next, one or more interface pads <NUM>-<NUM> are cut to a desired size and/or shape from the layered materials, such as with a die cut machine (block <NUM>).

At block <NUM>, the release layer is removed, and the adhesive layer is applied to either to an operating end of an ultrasound transducer or directly to the region of interest on the patient. For example, release layer <NUM> is removed to expose the tacky side of adhesive layer <NUM> and adhesive layer <NUM> is then applied to transducer <NUM> or patient <NUM>. Next, at block <NUM>, the hydrophilic layer is activated. For example, hydrophilic layer <NUM> is activated using water or saline. Finally, either the ultrasound transducer with the activated interface pad <NUM>-<NUM> secured thereto is applied to a region of interest on a patient or the ultrasound transducer is applied to the activated interface pad <NUM>-<NUM> secured to the patient (block <NUM>).

Consistent with embodiments described herein, the interface pad may be packaged as either a sterile or a non-sterile product for use in different medical environments or circumstances.

No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention ,which scope is defined by the appended claims, unless explicitly described as such. Also, as used herein, the article "a" is intended to include one or more items. Further, the phrase "based on" is intended to mean "based, at least in part, on" unless explicitly stated otherwise.

Claim 1:
An ultrasound transducer interface pad, comprising:
a first substrate layer (<NUM>) having a first surface and a second surface;
a hydrophilic layer (<NUM>) formed on the first surface of the first substrate layer, wherein the hydrophilic layer is configured to be hydrated to provide an acoustic coupling between an ultrasound transducer and a patient;
a second substrate layer (<NUM>) having a third surface and a fourth surface;
a first adhesive layer (<NUM>) formed on the third surface of the second substrate layer and configured to adhere to the second surface of the first substrate layer; and
a second adhesive layer (<NUM>) formed on the fourth surface of the second substrate layer and configured to adhere to an operational portion of an ultrasound transducer,
characterized in that:
the first adhesive layer comprises a non-silicon-based adhesive including an acrylic rubber-based adhesive material or a synthetic rubber-based adhesive material,
and the second adhesive layer comprises a silicone-based adhesive, and wherein the non-silicone-based adhesive exhibits a first removal force greater than a second removal force of the silicone-based adhesive.