Patent Description:
<CIT> discloses an imaging catheter comprising a plurality of segments along the length of the catheter body. The catheter may be provided so that the stiffness of different ones of the plurality of segments may be different.

<CIT> discloses a lined variable braided differential durometer multi-lumen catheter shaft.

<CIT> discloses a catheter including a liner, a braid, and an outer jacket assembled to provide varying flexibility along a length of the catheter.

Transesophageal echocardiography (TEE) is one type of diagnostic medical procedure that uses ultrasound to create very clear images of the heart structure, valves and arteries. The TEE transducer is attached to a tube that is inserted through the mouth, down the throat and into the esophagus. Generally, the tube includes a bending neck on which the TEE transducer is disposed, and an insertion tube disposed between the bending neck and the clinician. During a procedure, the clinician guides the TEE transducer to a desired location in the esophagus by pushing on the insertion tube. To achieve clear images reliably, the TEE probe tip needs to remain stable and maintain good contact to the esophagus wall.

While TEE exams have relatively low complication rates, some common side effects are common in known TEE devices that cause discomfort for the patient during and after the procedure. Consequences of manipulating the TEE transducer to achieve desired images include discomfort from gagging, esophagus irritation, bleeding (rare) and sore throat post-procedure.

These discomforts are a result of comparatively large transducer heads and comparatively large diameter insertion tubes. While an overall smaller diameter TEE transducer is desirable as it would make intubation less traumatic and more comfortable for patients, image quality may be compromised due to poor contact of the TEE transducer tip with the esophagus using known components. Moreover, the known comparatively large diameter insertion tubes include all electrical elements (e.g., cables), as well as pull cables used to manipulate the position of the transducer head during the procedure.

While improvements have been made in TEE transducers that enable fewer electrical cables in the insertion tube (and thus a reduction of the outer diameter (OD) of the insertion tube), the transfer of forces by the clinician needed to properly guide and locate the TEE transducer can suffer due to an overall lower durometer value of known lower OD insertion tubes. As will be appreciated, proper location of the TEE transducer is important to obtaining the best available image quality.

What is needed, therefore, is a TEE transducer assembly that reduces irritation and patient discomfort, while providing high quality images.

The representative embodiments are best understood from the following detailed description when read with the accompanying drawing figures. It is emphasized that the various features are not necessarily drawn to scale. In fact, the dimensions may be arbitrarily increased or decreased for clarity of discussion. Wherever applicable and practical, like reference numerals refer to like elements.

In the following detailed description, for purposes of explanation and not limitation, representative embodiments disclosing specific details are set forth in order to provide a thorough understanding of an embodiment according to the present teachings. Descriptions of known systems, devices, materials, methods of operation and methods of manufacture may be omitted so as to avoid obscuring the description of the representative embodiments but may be used in embodiments. It is to be understood that the terminology used herein is for purposes of describing particular embodiments only and is not intended to be limiting. The defined terms are in addition to the technical and scientific meanings of the defined terms as commonly understood and accepted in the technical field of the present teachings.

It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements or components, these elements or components should not be limited by these terms. These terms are only used to distinguish one element or component from another element or component. Thus, a first element or component discussed below could be termed a second element or component without departing from the teachings of the inventive concept.

The terminology used herein is for purposes of describing particular embodiments only and is not intended to be limiting. As used in the specification and appended claims, the singular forms of terms 'a', 'an' and 'the' are intended to include both singular and plural forms, unless the context clearly dictates otherwise. Additionally, the terms "comprises", and/or "comprising," and/or similar terms when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. As used herein, the term "and/or" may be used and includes any and all combinations of one or more of the associated listed items.

Unless otherwise noted, when an element or component is said to be "connected to", another element or component, it will be understood that the element or component can be directly connected to the other element or component, or intervening elements or components may be present. That is, these and similar terms encompass cases where one or more intermediate elements or components may be employed to connect two elements or components.

Various apparatus are described herein for use in ultrasound imaging. In accordance with various representative embodiments, the apparatuses may be a TEE assembly, or an ultrasound intra-cardia echo (ICE) imaging assembly, or an intravascular ultrasound (IVUS) assembly. It is emphasized that the present teachings are not limited to the noted assemblies, and may be applied to other ultrasound devices within the purview of one of ordinary skill in the art, having had the benefit of the present disclosure.

<FIG> is a partial cross-sectional view of an apparatus <NUM> inserted down an esophagus <NUM> of a patient <NUM> in accordance with a representative embodiment. The apparatus <NUM> comprises an insertion tube <NUM> at a proximal end <NUM>. A distal end <NUM> of the insertion tube <NUM> is connected to a proximal end (see <FIG>) of a bending neck <NUM>. A distal end <NUM> of the bending neck <NUM> is connected to a proximal end (see <FIG>) of a transducer assembly <NUM>. Accordingly, the transducer assembly <NUM>, the bending neck <NUM>, and the insertion tube <NUM> are disposed in tandem.

The transducer assembly <NUM> is positioned in the esophagus <NUM> to foster high-quality echocardiography images of a heart <NUM> of the patient. As described more fully below, the proximal end <NUM> of the insertion tube <NUM> is manipulated by a clinician's hands <NUM> to guide the transducer assembly <NUM> in position for image gathering.

As will become clearer as the present teachings continue, the components of the apparatus <NUM> have dimensions that are smaller than the esophagus <NUM>, but does not compromise image quality. To this end, the insertion tube <NUM>, the bending neck <NUM>, and the transducer assembly <NUM> each have a diameter or cross-sectional dimension that is less than the diameter or the cross-sectional dimension of the esophagus <NUM>. However, as explained more fully below, the manipulation of the insertion tube <NUM>, the bending neck <NUM> and the transducer assembly <NUM> by a clinician's hands <NUM> are not compromised by the reduced dimensions of the components of the apparatus <NUM> compared to known TEE assemblies, which have comparatively large components.

The transducer assembly <NUM> may be as described in <CIT> entitled "Intraluminal Imaging Devices with a Reduced Number of Signal Channels". Notably, the transducer assembly <NUM> as described in that application reduces the number of electrical cables needed for signal and power transmission to/from the transducer assembly <NUM>, while maintaining the needed number of pull cables. This reduction in electrical cables, when compared to known TEE assemblies, fosters a reduced diameter/cross-sectional area needed to provide all needed electrical and mechanical connections from the ultrasound equipment (not shown) through the insertion tube <NUM> and the bending neck <NUM> to the transducer assembly <NUM>. Moreover, compared to certain known transducer assemblies, the transducer assembly <NUM> has a smaller diameter/cross-section.

The reduction of dimensions of the insertion tube <NUM>, the bending neck, and the transducer assembly <NUM> of the present teachings, compared to known components of TEE assemblies, reduces contact of these components of the apparatus <NUM> with the esophagus, and beneficially improves patient comfort. As described more fully below, however, the improvements of the apparatus <NUM> in comfort do not compromise image quality since dexterity of placement of the transducer assembly <NUM> in a location needed for proper imaging of the heart <NUM> and its surrounding structures are not compromised.

<FIG> is a perspective view of apparatus <NUM> in accordance with a representative embodiment. Many aspects of the apparatus <NUM> are common to those described in connection with <FIG>, and may not be repeated.

The apparatus <NUM> comprises insertion tube <NUM> having proximal end <NUM>. The distal end <NUM> of the insertion tube <NUM> is connected to a proximal end <NUM> of a bending neck <NUM>. The distal end <NUM> of the bending neck <NUM> is connected to a proximal end <NUM> of the transducer assembly <NUM>. Accordingly, the transducer assembly <NUM>, the bending neck <NUM>, and the insertion tube <NUM> are disposed in tandem.

In accordance with a representative embodiment, the stiffness of the proximal end <NUM> of insertion tube <NUM> is greater than the stiffness of the distal end <NUM> of the insertion tube <NUM>. This comparatively high durometer value of the proximal end <NUM> of the insertion tube <NUM> provides a rigidity that is greater than the rigidity of the distal end <NUM> of the insertion tube <NUM>. As will be appreciated by one of ordinary skill in the art, it is beneficial to have a comparatively high durometer value for the proximal end <NUM> of the insertion tube <NUM> in order to properly transfer torque from the user to the insertion tube <NUM> to enable manipulation and articulation of the transducer assembly <NUM> as far as its distal end.

In accordance with a representative embodiment along its length, the insertion tube <NUM> has a durometer value in the range of approximately <NUM> Shore D to approximately <NUM> Shore D, with the higher value at the proximal end <NUM> and the lower value at the distal end <NUM>.

Accordingly, the stiffness and thus the relative rigidity of the apparatus <NUM> decreases along its length from the proximal end <NUM> of insertion tube <NUM> to the distal end of the insertion tube. The change in stiffness along the length of the insertion tube <NUM> can be comparatively continuous, continual, or abrupt. As described more fully below, the insertion tube <NUM> can be fabricated so the stiffness decreases continuously or continually from its proximal end <NUM> to its distal end <NUM>.

It is noted that in combinations of the above-described components of the apparatus <NUM>, the stiffness of the bending neck <NUM> and the transducer assembly <NUM> are generally fixed, and driven by the insertion tube <NUM>. As described more fully below for example, the insertion tube <NUM> may be fabricated so its stiffness continuously, continually, or abruptly decreases between its proximal end <NUM> and its distal end <NUM>. This insertion tube <NUM> may be connected in tandem to the bending portion that has a constant stiffness between its proximal end <NUM> and its distal end <NUM>. Taking this example further, the change in stiffness from the proximal end <NUM> to the distal end <NUM> of the insertion tube <NUM> can be made so there is no change in stiffness from the distal end <NUM> of the insertion tube <NUM> to the proximal end <NUM> of the bending neck <NUM> (i.e., the durometer value at the distal end <NUM> of the insertion tube <NUM> is substantially identical to the durometer value at the proximal end <NUM> of the bending neck <NUM>).

Regardless of whether the decrease in the durometer value between the proximal end <NUM> to the distal end <NUM> of the insertion tube <NUM> is continuous, or continual, or abrupt, the durometer value along the length of the insertion tube <NUM> is selected to transfer sufficient torque along the insertion tube <NUM>, which has a reduced diameter/cross-section compared to known insertion tubes. This transfer of force is illustrated in <FIG>, which depicts apparatus <NUM> connected to a handle end <NUM>. To this end, rotation <NUM> by of the handle end <NUM> by the user rotates the proximal end <NUM> of the insertion tube <NUM> and transfers torque at the bending neck <NUM> and transducer assembly <NUM>, resulting in a rotation <NUM> of the transducer assembly <NUM>.

The higher stiffness of the proximal end <NUM> of the insertion tube <NUM> compared to those of distal end <NUM> enables sufficient transfer of torque from the clinician at the proximal end <NUM> of the insertion tube <NUM> to the bending neck <NUM> without sacrificing flexibility in the bending neck <NUM> and transducer assembly <NUM> to move within the esophagus. As such, by the present teachings, a more patient-friendly apparatus <NUM>, having a smaller cross-section is provided, while allowing allows proper articulation of the transducer assembly <NUM> in order to provide better quality images. By contrast to the present teachings, reducing the diameter/cross-section of known insertion tubes to those of the present teachings, while potentially beneficial to patient comfort, result in an unacceptably low durometer value, and ultimately unacceptable dexterity of the transducer assembly to enable images of acceptable quality.

<FIG> is a perspective view of a bending neck <NUM> connected to an insertion tube <NUM> in accordance with a representative embodiment. Certain aspects of the bending neck <NUM> connected to an insertion tube <NUM> are common to those described in connection with representative embodiments described in connection with <FIG>, and may not be repeated.

The insertion tube <NUM> has a proximal end <NUM> and a distal end <NUM>. The distal end <NUM> of the insertion tube <NUM> is connected to a proximal end <NUM> of a bending neck <NUM>. In a representative embodiment, a suitable adhesive <NUM>, such as an epoxy that may be used in invasive medical procedures, is used to adhere the distal end <NUM> of the insertion tube <NUM> to the proximal end <NUM> of the bending neck <NUM>. As will be appreciated, a distal end <NUM> of the bending neck <NUM> is connected to a proximal end (not shown in <FIG>) of a transducer assembly (not shown in <FIG>). Accordingly, the transducer assembly, the bending neck <NUM>, and the insertion tube <NUM> are disposed in tandem.

In a representative embodiment, the bending neck <NUM> and insertion tube <NUM> are cylindrical in shape, and have a diameter measured along the z-axis of the coordinate system of <FIG>. As noted above, and as described more fully herein, the diameter of the insertion tube <NUM> is smaller than the diameter of the bending neck <NUM>, and may be beneficially smaller than the diameter of known insertion tubes, while having a durometer value that is at least as great as known insertion tubes. More generally, the cross-sectional area (measured in the y-z plane of the coordinate system of <FIG>) of the insertion tube <NUM> is less than the cross-sectional area of the bending neck <NUM>, and may be beneficially smaller than the diameter of known insertion tubes, while having a durometer value that is at least as great as known insertion tubes.

<FIG> is a cross-sectional view of the insertion tube <NUM> of <FIG> along the line 2B-2B. <FIG> is a cross-sectional view of the insertion tube <NUM> of <FIG> along the line 2C-2C. <FIG> is a perspective view of an inner jacket <NUM> in accordance with a representative embodiment. Certain aspects of the insertion tube <NUM> are common to those described in connection with representative embodiments described in connection with <FIG>, and may not be repeated.

As shown in <FIG>, the insertion tube <NUM> has an interior channel <NUM>, which is configured to hold an electrical wire (not shown) used to transmit signals to/from the transducer assembly (not shown in <FIG>), as well as pull cables (not shown) used for manipulation of the transducer assembly during a medical procedure. Illustratively, the interior channel <NUM> has a diameter of approximately <NUM> to approximately <NUM>.

In a representative embodiment, an inner jacket <NUM> is disposed circumferentially around the interior channel <NUM>. As described in greater detail in connection with <FIG>, and more fully below, the inner jacket <NUM> may be used to provide a desired stiffness along a length (x-direction in the coordinate system of <FIG>) of the insertion tube <NUM>.

Circumferentially surrounding the inner jacket <NUM> is a braid <NUM>. As described more fully below, the braid <NUM> may also be used to provide to provide a desired stiffness along a length (x-direction in the coordinate system of <FIG>) of the insertion tube <NUM>.

Circumferentially surrounding braid <NUM> is an outer jacket <NUM>. As described more fully below, the outer jacket <NUM> may also be used to provide to provide a desired durometer value along a length (x-direction in the coordinate system of <FIG>) of the insertion tube <NUM>.

In accordance with representative embodiments of the present teachings, each of, or one or more of, the inner jacket <NUM>, the braid <NUM>, and the outer jacket <NUM> are used selectively to provide a desired durometer value along the length of the insertion tube. As explained more fully below, not only can each of the inner jacket <NUM>, braid <NUM>, and outer jacket <NUM> be selected for placement along a length (x-direction of <FIG>) of the insertion tube <NUM> to provide a desired durometer value, but also their interaction along the length of the insertion tube <NUM> may be used to tailor the magnitude of the stiffness of the insertion tube <NUM> along its length. As described more fully below, through the use of one or more of the inner jacket <NUM>, braid <NUM>, and outer jacket <NUM>, the desired stiffness magnitude, change in magnitude in stiffness, and type of change in magnitude (i.e., continuous, continual, discrete) in the stiffness along the length of the insertion tube <NUM> can be realized.

Returning to <FIG>, therefore, in accordance with various representative embodiments, the stiffness of the insertion tube <NUM> at its distal end <NUM> can be less than at its proximal end <NUM>, with the inner jacket <NUM>, braid <NUM>, and outer jacket <NUM> used to tailor the desired durometer magnitude, change in magnitude, and type of change in magnitude (i.e., continuous, continual, discrete) in the stiffness of the insertion tube <NUM> between its proximal end <NUM> and distal end <NUM>. Moreover, and as described more fully below, the inner jacket <NUM>, braid <NUM>, and outer jacket <NUM> may be used in combination, or selectively omitted, or both, to provide the desired magnitude, change, and type of change in the stiffness of the insertion tube <NUM> between its proximal end <NUM> and distal end <NUM>.

In accordance with a representative embodiment, and as shown in <FIG>, the inner jacket <NUM> is a monocoil with a helical shape. The inner jacket <NUM> is used to provide a stiffer durometer value at the proximal end <NUM> than at the distal end <NUM> of the insertion tube <NUM>, thereby improving, compared to known insertion tubes, the ability to transfer torque from the proximal end <NUM> to the distal end <NUM> of the insertion tube <NUM> without losing flexibility needed to move the transducer assembly (e.g., transducer assembly <NUM> of <FIG>) within the body. Notably, and in accordance with a representative embodiment, the stiffness of the durometer provided by the inner jacket <NUM> can be increased by stacking more than one (e.g., two) inner jacket <NUM> upon each other at locations along the length (x-direction in the coordinate system of <FIG>) where an comparatively stiff durometer. So, to increase the durometer value along the proximal end <NUM> of the insertion tube <NUM>, two (or more) inner jackets <NUM> may be stacked upon one another along the desired length of the proximal end <NUM> of the insertion tube. By contrast, the relative stiffness of the insertion tube <NUM> at the distal end <NUM> can be desirably reduced by foregoing the inner jacket <NUM> in one or more portions of the insertion tube <NUM>.

Illustratively, the inner jacket <NUM> comprising the monocoil is made of a suitable metal or metal alloy. Alternatively, the monocoil may be made of a synthetic material such as Kevlar®. The gauge or thickness of the material used for the monocoil is selected to provide a desired rigidity and durometer value along the length (x-direction in the co ordinate system of <FIG>) of the monocoil and inner jacket. Similarly, the pitch of the helix (see <FIG>) of the monocoil can be altered to provide a desired rigidity and durometer value along the length of the monocoil, and thus the inner jacket. As such, the stiffness of the inner jacket <NUM> can be varied along the length (e.g., from the proximal end <NUM> to the distal end <NUM>) of the insertion tube <NUM> by selection of the gauge or thickness, or pitch of the monocoil, or both, by selectively stacking and/or foregoing the monocoil or combinations thereof, at selected portions of along the length of the monocoil that comprises the inner jacket <NUM>. By way of illustration and not limitation, the monocoil configuration may comprise flat wire having a width of approximately <NUM> to approximately <NUM> and a thickness of approximately <NUM> to approximately <NUM>. The wraps of the monocoil can range from touch (i.e., no gap) to spaced wraps having a gap as great as <NUM>. Alternately, the shape of the monocoil can be round or elliptical.

As alluded to above, in accordance with a representative embodiment, the braid <NUM> may also be used to provide a desired stiffness along the length (x-direction in coordinate system of <FIG>). Like the inner jacket <NUM>, the braid <NUM> is used to provide a stiffer durometer at the proximal end <NUM> than at the distal end <NUM> of the insertion tube <NUM>, thereby improving, compared to known insertion tubes, the ability to transfer torque from the proximal end <NUM> to the distal end <NUM> of the insertion without losing flexibility needed to move the transducer assembly (e.g., transducer assembly <NUM> of <FIG>) within the body.

As described more fully below in connection with <FIG>, the stiffness of the braid <NUM> can be selected along a length (x-direction of <FIG>) of the insertion tube <NUM>. Illustratively, the braid angle and the tensile modulus of the individual wires that make up the braid <NUM> can be selected to provide a desired stiffness at a location along the braid <NUM>, and to alter the stiffness of the braid continually, continuously, or abruptly along the length of the insertion tube <NUM>.

Illustratively, the braid <NUM> is made of a suitable metal or metal alloy. Alternatively, the monocoil may be made of a synthetic material such as Kevlar®. As described more fully below in connection with <FIG>, the braid angle, or the tensile modulus of the material used for the wires of the braid <NUM>, or both, are selected to provide a desired rigidity and durometer value along the length (x-direction in the coordinate system of <FIG>) of the monocoil and inner jacket <NUM>.

In accordance with a representative embodiment, the outer jacket <NUM> may also be used to provide a desired durometer value along the length (x-direction in coordinate system of <FIG>). Notably, the in certain embodiments, the braid <NUM> is adhered to an outer jacket <NUM> with adhesive. In this way, the braid <NUM> can be captured between the inner jacket <NUM> and the outer jacket <NUM> as a separate layer. Alternatively, the braid <NUM> is thermally bonded to the outer jacket <NUM>. By way of example, the outer jacket <NUM> can be laminated to the braid <NUM> via co-extrusion or other known methods.

Like the inner jacket <NUM> and the braid <NUM>, the outer jacket <NUM> is used to provide a stiffer durometer value at the proximal end <NUM> than at the distal end <NUM> of the insertion tube <NUM>, thereby improving, compared to known insertion tubes, the ability to transfer torque from the proximal end <NUM> to the distal end <NUM> of the insertion tube <NUM> without losing flexibility needed to move the transducer assembly (e.g., transducer assembly <NUM> of <FIG>) within the body.

Like the inner jacket <NUM> and the braid <NUM>, the stiffness of the outer jacket <NUM> can be selected along a length (x-direction of <FIG>) of the insertion tube <NUM>. Illustratively, as noted above, the durometer value of the outer jacket <NUM> can be made to vary continually, continuously, or abruptly along the length of the insertion tube <NUM>. Construction of the desired stiffness profile along the length of the insertion tube <NUM> can be achieved by attaching various tubing by adhesive or thermally bonding or alternately via continuous variable extrusion methods. Just by way of illustration, the outer jacket <NUM> may comprise tubing commercially available from Putnam Plastics, Dayvillle, CT (USA). The stiffness of the outer jacket along the length of the insertion tube <NUM> using Total Intermittent Extrusion (TIE™) by Putnam Plastics. This proprietary process is capable of producing extrusions with variable durometer values along their length. (http://www. putnamplastics. com/extrusions/intermittent-extrusion-tie). ) As such, the magnitude of the stiffness of the insertion tube <NUM> along the proximal end <NUM> can be made greater than at the distal end <NUM> of the insertion tube <NUM> by the selection of the extrusion to provide the greater and lesser durometer values at the proximal end <NUM> and the distal end <NUM>, respectively. Moreover, the extrusion process can be used to provide an outer jacket <NUM> having a durometer value that varies continually, continuously, or abruptly along the length of the insertion tube <NUM>.

As noted above, each of the inner jacket <NUM>, the braid <NUM>, and the outer jacket <NUM> can be used selectively to provide the desired stiffness profile along the length (x-direction of <FIG>) of the insertion tube <NUM>. To this end, the braid <NUM>, and the outer jacket <NUM> can be used or foregone along portions of the length of the insertion tube <NUM> to provide desired durometer magnitudes along the length of the insertion tube <NUM>. Moreover, the selected stiffness of the outer jacket <NUM> can be selected to provide a desired durometer value at locations along the length of the insertion tube <NUM>. As such, by the selective incorporation of the outer jacket <NUM> with the braid <NUM>, or the inner jacket <NUM>, the stiffness along the length of the insertion tube <NUM> can be varied as desired. As such, the insertion tube <NUM>, having a variable durometer value along its length, can be realized by using the outer jacket <NUM> alone; or by incorporating the braid <NUM>, or the inner jacket <NUM>, or both, with the outer jacket <NUM>.

The flexibility of the insertion tube <NUM> can also be tailored with combinations by selection of the durometer value of the plastic/polymer materials, and the modulus of the reinforcement metal materials such as the monocoil. For example, the durometer value of the inner jacket <NUM>, or the outer jacket <NUM>, or both, can be substantially constant along the length (along the x-axis in <FIG>) of the insertion tube <NUM>, and the stiffness of the insertion tube <NUM> can be altered by varying the characteristics of the braid <NUM>. This variation of the durometer can be made by selection of the monocoil material, stress modulus, shape, or configuration (e.g., round monocoil, flat monocoil, and spacing of coils of the monocoils) of the braid <NUM>. Alternatively, the properties and configurations of the inner jacket <NUM>, the outer jacket <NUM> and the monocoil can be varied to realize the desired durometer value profile along the length (along the x-axis in <FIG>) of the insertion tube <NUM>.

<FIG> is a perspective view of insertion tube <NUM> in accordance with a representative embodiment. Notably, for ease of description, the outer jacket (e.g., outer jacket <NUM> of <FIG>) and the inner jacket (e.g., inner jacket <NUM> of <FIG>) are not shown in <FIG> in order to facilitate the description of the braid <NUM> along the length of the insertion tube <NUM>. Certain aspects of the insertion tube <NUM> are common to those described in connection with representative embodiments described in connection with <FIG>, and may not be repeated.

The insertion tube <NUM> has a first section <NUM>, a middle section <NUM>, and a second section <NUM>. The first section <NUM> has a comparatively high durometer value; the middle section <NUM> has a lower durometer value than the first section <NUM>; and the second section <NUM> has a durometer value that is lower than the middle section <NUM> or the first section <NUM>.

As noted above, the braid angle is one determinant of the durometer value of the braid <NUM>. As shown in the inset of <FIG>, a first braid <NUM> having a braid angle of <NUM>° and a second braid <NUM> has a braid angle of <NUM>°. As is known, the rigidity (and thus the durometer value) of a braid is inversely dependent upon the braid angle. As such, the second braid <NUM> has a greater durometer value (and therefore is stiffer) than the first braid <NUM>. Similarly, a third braid <NUM> having, an illustrative braid angle of <NUM>° is between the braid angles of the first braid <NUM> and the second braid <NUM>, is disposed in the middle section <NUM>. As such, the middle section 311has a durometer value that is greater than that of the first braid <NUM> and less than that of the second braid <NUM>.

In the presently described embodiment, the braid angle of the first section <NUM> is less than the braid angle of the middle section <NUM>, and even less than the braid angle of the second section <NUM>. This provides the first section <NUM> with a comparatively high durometer value; the middle section <NUM> with a lower durometer value than the first section <NUM>; and the second section <NUM> with a durometer value that is lower than the middle section <NUM> or the first section <NUM>. It is emphasized that the braid angle is only one of the factors that impacts the durometer value of a braid <NUM>. As noted above, the tensile strength of the individual wires or fibers of the braid <NUM> also impact the magnitude of the durometer value of the braid <NUM>. By the present teachings, the durometer value of the braid <NUM> is set by the selection of the braid angle, or by selection of the tensile strength of the braid <NUM>, or both.

Notably, and as shown by the abrupt increase of the braid angle as shown, the change in durometer value between the first section <NUM> and the middle section <NUM> is comparatively abrupt. Similarly, the change in stiffness between the middle section <NUM> and the second section <NUM> is also abrupt, as evidenced by the abrupt increase in the braid angle of the second section <NUM> compared to the middle section <NUM>. This is merely illustrative. In other representative embodiments described below, a continuous change in the braid angle of the braid <NUM> can be used to provide a change in the stiffness from the first section <NUM> to the middle section <NUM> and the second section <NUM>.

Additionally, the change in the braid angle can be continual along the length (x-direction of <FIG>) of the insertion tube <NUM>. To this end, and as described more fully below, rather than an abrupt change in braid angle between the first section <NUM> and the middle section <NUM>, or between the middle section <NUM> and the second section <NUM>, or both, or a continuous change in the braid angle along the length (x-direction of <FIG>) between the first section <NUM> and the second section <NUM>, the braid angle can change gradually in the regions near the first section <NUM> and the middle section <NUM>, or near the middle section <NUM> and the second section <NUM>, or both.

<FIG> is a partial cross-sectional view of an apparatus <NUM> inserted down an esophagus <NUM> of a patient <NUM> in accordance with a representative embodiment. Certain aspects of the insertion tube <NUM> are common to those described in connection with representative embodiments described in connection with <FIG>, and may not be repeated.

The apparatus <NUM> comprises an insertion tube <NUM> at a proximal end <NUM>. A distal end <NUM> of the insertion tube <NUM> is connected to a proximal end <NUM> of a bending neck <NUM>. A distal end <NUM> of the bending neck <NUM> is connected to a proximal end of a transducer assembly <NUM>. Accordingly, the transducer assembly <NUM>, the bending neck <NUM>, and the insertion tube <NUM> are thus disposed in tandem.

The transducer assembly <NUM> is positioned in the esophagus <NUM> to foster high-quality echocardiography images of a heart <NUM> of the patient. During an imaging and/or treatment procedure, the proximal end <NUM> of the insertion tube <NUM> is manipulated by a clinician's hands to guide the transducer assembly <NUM> in a desired position.

As noted above, the braid angle of the first section <NUM> is less than the braid angle of the middle section <NUM>, and even less than the braid angle of the second section <NUM>. This provides the first section <NUM> with a comparatively high durometer value; the middle section <NUM> with a lower durometer value than the first section <NUM>; and the second section <NUM> with a durometer value that is lower than the middle section <NUM> or the first section <NUM>. It is noted that the use of three sections having different durometer values is merely illustrative. In certain representative embodiments, the insertion tube <NUM> has two sections, with the transition from one section to another being continuous or continual or abrupt. In yet other embodiments, there are more than three sections, and again, the transition from one section to another being continuous or continual or abrupt. Finally, as noted above, instead of, or in addition to, the modification of the braid angle to tailor the desired changes in the durometer value, the desired changes in durometer value along the length of the insertion tube may be effected by selection of the tensile strength of the braid.

In a representative embodiment, the insertion tube <NUM> has a length of approximately <NUM> meter. The first section <NUM> is comparatively straight, and has a length between approximately <NUM> and approximately <NUM>. The middle section <NUM>, which is an intermediate transition region, has a length between approximately <NUM> and approximately <NUM>. The second section <NUM> has a length between approximately <NUM>-<NUM> centimeters. Notably, the angular region <NUM> of section <NUM> is typically approximately <NUM> to approximately <NUM> in length, and transitions over an angle of approximately <NUM>° and <NUM>°.

The durometer value along the length of the insertion tube <NUM> is selected to transfer sufficient torque along the insertion tube <NUM>, which has a reduced diameter/cross-section compared to known insertion tubes. The large durometer value of the insertion tube <NUM> compared to those of the bending neck <NUM> and transducer assembly <NUM> enables sufficient transfer of torque from the clinician at the proximal end <NUM> of the insertion tube <NUM> to the bending neck <NUM> without sacrificing flexibility in the bending neck <NUM> and the transducer assembly <NUM> to move within the esophagus. As such, by the present teachings, a more patient-friendly apparatus <NUM> is provided, which allows proper articulation of the transducer assembly <NUM> in order to provide quality images, and to carry out procedures with desired precision.

<FIG> is a side view of a portion of a braid <NUM> useful in the apparatuses described above, in accordance with a representative embodiment. Many aspects of the apparatuses are common to the apparatuses described above, and may not be repeated in the interest of clarity of description.

The braid <NUM> has a continuous change in braid angle along a length (x-direction in the coordinate system of <FIG>) from a first section <NUM>, to a second <NUM>, and a third section <NUM> between a first end <NUM> and a second end <NUM>. In the representative embodiment, the braid angle increases in magnitude from the first end <NUM> to the second end <NUM>, and gradually between the first~third sections <NUM>-<NUM>. Just by way of illustration, <FIG> shows a section of the braid <NUM> near the first end <NUM> in the first section <NUM>, and the braid angle at this section is approximately <NUM>°. <FIG> shows another section of the braid <NUM> near the second end <NUM> in the third section <NUM>, and the braid angle at this section is approximately <NUM>°.

The braid <NUM> has a continuous change in braid angle along a length (x-direction in the coordinate system of <FIG>) between a first end <NUM> and a second end <NUM>. As depicted in <FIG>, the braid angle decreases between the first end <NUM> and the second end <NUM>.

Although apparatuses of the present teachings have been described with reference to several representative embodiments, it is understood that the words that have been used are words of description and illustration, rather than words of limitation. Changes may be made within the purview of the appended claims without departing from the scope of the patent. Although the illustrative apparatuses and systems that include these apparatuses of representative embodiments have been described with reference to particular means, materials and embodiments, the scope is not intended to be limited to the particulars disclosed, but extends to all functionally equivalent structures that are within the scope of the appended claims.

The illustrations are not intended to serve as a complete description of all of the elements and features of the disclosure described herein.

One or more embodiments of the disclosure may be referred to herein, individually and/or collectively, by the term "invention" merely for convenience and without intending to voluntarily limit the scope of this application to any particular invention or inventive concept. Moreover, although specific embodiments have been illustrated and described herein, it should be appreciated that any subsequent arrangement designed to achieve the same or similar purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all subsequent adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the description.

In the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all of the features of any of the disclosed embodiments. Thus, the following claims are incorporated into the Detailed Description, with each claim standing on its own as defining separately claimed subject matter.

Claim 1:
An apparatus (<NUM>,<NUM>), comprising:
a transducer assembly (<NUM>, <NUM>);
a bending neck (<NUM>, <NUM>, <NUM>) connected to a proximal end (<NUM>) of the transducer assembly (<NUM>, <NUM>); and
an insertion tube (<NUM>, <NUM>, <NUM>) disposed in tandem with the bending neck (<NUM>, <NUM>, <NUM>) and comprising a distal end (<NUM>, <NUM>, <NUM>) connected to a proximal end (<NUM>, <NUM>, <NUM>) of the bending neck (<NUM>,<NUM>, <NUM>), and a proximal end (<NUM>, <NUM>, <NUM>) for manipulation of the transducer assembly (<NUM>, <NUM>), the insertion tube (<NUM>, <NUM>, <NUM>) having a first durometer value at a first section (<NUM>), and a second durometer value at a second section (<NUM>), wherein the first durometer value is greater than the second durometer value, wherein the first section extends along a length of the insertion tube starting from the proximal end of the insertion tube, wherein the second section extends along a length of the insertion tube starting from the distal end of the insertion tube, wherein the first and second sections do not overlap, and wherein the insertion tube further comprises an interior channel (<NUM>);
characterized in that the insertion tube comprises an inner jacket (<NUM>) disposed circumferentially around the interior channel <NUM>, wherein the inner jacket is a monocoil with helical shape, wherein a stiffness of the inner jacket is varied along the length of the insertion tube by selection of:
a gauge, a thickness or a pitch of the monocoil; or
by stacking and/or foregoing the monocoil at selected portions along the length of the monocoil that comprises the inner jacket.