Damping cushion for ultrasound probes

An ultrasonic probe is provided. The probe includes a base member and an ultrasonic transducer housed by the base member. The probe also includes an intermediary damping member secured to the base member. The damping member includes an interior cavity for receiving an acoustic coupling fluid. The probe may optionally be secured to a flexible intermediary buffer. In an alternative embodiment, a coupling member is secured to the base member. The coupling member includes an interior cavity for receiving an acoustic coupling fluid. The coupling member also includes a malleable contacting surface for contacting an anatomical structure during use. Another alternative embodiment of the invention includes a transducer housing, an ultrasonic transducer mounted in the housing, and a flexible cushioned pad directly secured to a periphery of the transducer housing. Yet another alternative embodiment includes a pliable damping member defining an interior for retaining a fluid and structure for secured the damping member to an ultrasonic probe.

BACKGROUND OF THE INVENTION
 The present invention generally relates to ultrasound probes and in
 particular to ultrasound probe and handle housings and cushions for use
 with ultrasound probes.
 Ultrasonic diagnostic imaging probes generally have been used in the past
 to image anatomical structures within the body. Ultrasonic probes have
 been used in the past during non-invasive procedures (such as
 trans-thoracic probes), during invasive procedures (such as
 trans-esophageal echocardiography (TEE) probes and trans-vaginal probes),
 and during surgical procedures (i.e., intraoperative probes).
 When using ultrasonic probes, it is important that the hand of the
 physician using the probe not obscure the site being examined. While the
 probe is imaging, for example, a physician must be able to accurately
 determine and maintain the position of the probe while looking at a
 monitor displaying the information obtained from the probe.
 Past intraoperative ultrasound probes have provided, for example in U.S.
 Pat. No. 5,381,795 to Nordgren et al., an intraoperative ultrasound probe
 having a transducer section and an angled handle section that form an
 obtuse angle with respect to one another. The shape of the handle was used
 in an attempt to permit the physician to grasp the probe without blocking
 the physician's view of the surgical site. Surgical procedures in which
 intraoperative probes have been used include vascular surgery and
 transplant surgery. During vascular surgery, ultrasonic imaging probes can
 be used to image and diagnose the interior of carotid arteries. In
 transplant surgery, intraoperative ultrasonic probes can be used to verify
 successful attachment and function of renal arteries. Intraoperative
 ultrasound probes are preferably small and as easy to manipulate as
 surgical instruments.
 Past trans-vaginal probes have provided, for example in U.S. Pat. No.
 4,742,829 to Law et al., a handle offset from the central axis of the
 probe. The shape of the handle was used in an attempt to free the space
 around the entrance of a needle guide to thereby permit manipulation of
 the needle by hand. The probes disclosed in the above-referenced patents
 did not, however, present a probe having a multiple-angled handle section.
 Past TEE probes have provided, for example in U.S. Pat. No. 5,351,691 to
 Brommersma, a flexible tube having at one end a probe head. The flexible
 end part is connected to a housing to allow a probe head to be bent
 forwards or backwards.
 Several problems exist with respect to past ultrasound probes. During
 examination of organs within the body, particularly during intraoperative
 examination, the quality of ultrasound images is adversely affected by the
 presence of a moving organ, due to, for example, blood pulsation. For
 example, an ultrasound probe may be placed directly on a heart during open
 heart surgery. The pulsation of the heart applies forces to the ultrasound
 probe which cause the probe to move up and down and/or side to side and
 therefore adversely affect the quality of the ultrasound images obtained.
 The images may be adversely affected because returning ultrasound waves
 may miss the probe altogether (thereby producing no image) or return when
 the probe is at a different angle or orientation than when the ultrasound
 wave was sent (thereby causing an incorrect image to be produced).
 Second, ultrasound images are adversely affected by the lack of an
 effective acoustic coupling due to the fixed (usually flat) transducer or
 probe surface and the curved or irregular shape of an anatomic structure,
 such as a heart, artery or other organ (especially during intraoperative
 examination). When a flat probe is placed against the curved or irregular
 surface of an anatomic structure, only a portion of the probe actually
 contacts the anatomic structure. When this occurs, air is located between
 the non-contacting portion of the probe surface and the anatomic
 structure. Ultrasonic waves travel at different speeds in air than in the
 anatomic structure. Because of the different speeds at which ultrasonic
 waves travel, the ultrasonic waves refract (i.e., bend sharply) when they
 enter and leave the anatomic structure. Because of this refraction or
 bending, the returning ultrasound waves may either appear to emanate from
 an incorrect location or miss the probe altogether. The existence of
 various, unpredictable air pockets between the probe and anatomic
 structure may be referred to as the lack of an effective acoustic
 coupling. A smaller number of air pockets between the probe surface and
 anatomic structure corresponds to a more effective acoustic coupling.
 Third, when using past ultrasound probes, it is difficult to obtain steady
 probe contact with an organ while not deforming the organ or its blood
 flow, especially during intraoperative examination. Organ deformation
 occurs because past ultrasound probes placed a rigid probe surface against
 the soft organ tissue. In order to achieve an effective acoustic coupling,
 a probe user may firmly press the probe against the anatomic structure
 sought to be imaged. This deformation adversely affects ultrasound image
 quality because an anatomic structure sought to be imaged may be deformed
 to an unnatural shape or the velocity of blood flow may be altered due to
 deformation. The alteration of blood flow may be a particular problem
 where blood flow pattern and/or velocity are sought to be imaged.
 Past ultrasound technology has not presented an ultrasonic probe that can
 avoid the aforementioned problems of organ movement during intraoperative
 ultrasound examination, the lack of an effective acoustic coupling, and
 deformation.
 A need has long existed for such a probe. A further need remains for an
 improved ultrasonic probe housing that enables a physician to accurately
 determine and maintain the position of the probe during use. A need also
 remains for an improved ultrasonic probe housing that allows the physician
 to move the probe while maintaining its orientation without having to view
 the probe to ensure it is oriented properly. It is an object of the
 present invention to meet these needs.
 BRIEF SUMMARY OF THE INVENTION
 In an exemplary embodiment of the invention, an ultrasonic probe is
 provided. The probe includes a base member and an ultrasonic transducer
 housed by the base member. The probe also includes an intermediary damping
 member secured to the base member. The damping member includes an interior
 cavity for receiving an acoustic coupling fluid. The probe may optionally
 be secured to a flexible intermediary buffer. In another exemplary
 embodiment of the invention, a coupling member is secured to the base
 member. The coupling member includes an interior cavity for receiving an
 acoustic coupling fluid. The coupling member also includes a malleable
 contacting surface for contacting an anatomical structure during use. An
 alternative embodiment of the invention includes a transducer housing, an
 ultrasonic transducer mounted in the housing, and a flexible cushioned pad
 directly secured to a periphery of the transducer housing. Another
 alternative embodiment includes a pliable damping member defining an
 interior for retaining a fluid and structure for secured the damping
 member to an ultrasonic probe.

DETAILED DESCRIPTION OF THE INVENTION
 This application is a continuation-in-part of Application No. 09/233,403,
 filed Dec. 30, 1998, the subject matter of which is hereby incorporated in
 its entirety by reference.
 FIG. 1 illustrates an ultrasonic probe and handle housing 100. The housing
 includes a base 102 and a stem extending from the base for handling the
 probe. The stem includes a first stem portion 104 and a second stem
 portion 106. A probe cable 107 extends from the second stem portion 106.
 FIG. 1A illustrates a view of the base 102 and first stem portion 104 of
 the housing 100. The longitudinal axis of the base 108, the longitudinal
 axis of the first stem portion 110, and the inclined angle 112 at which
 the two axes intersect are also shown.
 Turning to FIG. 1B, a top view of the probe and handle housing 100 is
 presented. The longitudinal axis along which the first stem portion
 extends 110, the longitudinal axis along which the second stem portion
 extends 114, and the angle 116 at which the axes intersect are shown.
 Turning back to FIG. 1, a base 102 is provided for use with ultrasonic
 imaging technology. In the present embodiment, the lower surface of the
 probe is rectangular in shape, although this is not required. The first
 stem portion 104 extends from the base 102. The first stem portion 104 may
 extend from the base 102 in one of several methods such as, for example,
 the stem portion 104 may be affixed to the base 102 or the stem portion
 104 and base 102 may be integrally molded. The first stem portion 104 may
 extend from the base 102 at any portion of the base 102, including at the
 center of the upper face of the base 102.
 Referring still to FIG. 1, a second stem portion 106 is merged with the
 first stem portion 104, preferably to the section of the first stem
 portion opposite the section of the first stem portion that extends from
 the base 102. The second stem portion 106 may be merged with the first
 stem portion 104 using one of several methods such as, for example, the
 second stem portion 106 may be affixed to the first stem portion 104 or
 the first and second stem portions 104, 106 may be integrally molded.
 Preferably, the first and second stem portions 104, 106 are rigid. To meet
 this preferred construction, the stem portions 104, 106 may be made of,
 for example, a hard plastic. If the probe housing is suited for use, for
 example, as an intraoperative probe housing, the housing 100 should be
 suitable for use in a sterile environment, such as in an operating room
 during surgery.
 As shown in FIG. 1A, the first stem portion 104 in this embodiment extends
 from the base 102 so that the first stem portion 104 extends along a
 longitudinal axis 110. The longitudinal axis 110 of the first stem portion
 104 preferably forms an inclined angle 112 with respect to the
 longitudinal axis 108 of the base, as shown in FIG. 1A. This relationship
 between the longitudinal axes of the base 108 and first stem portion 110
 permits, for example, the front portion of the base 102 to extend under a
 portion of unincised skin during an operation, as shown in FIG. 6. A
 physician may therefore obtain ultrasonic image information about
 anatomical structures above which the skin has not been cut. This
 relationship also permits the physician using the probe to be able to more
 accurately determine the position of the probe relative to the anatomical
 structure being monitored since the stem portions 104, 106 form a handle
 for the physician to hold onto the probe during usage. As a result, the
 physician is able to maintain an accurate sense of direction of the
 ultrasound beam and its relative position to the anatomical structure the
 physician is imaging. Additionally, if, for example, the probe handle were
 to extend from the base at a perpendicular angle (i.e., vertically with
 respect to the base), the physician's fingers would be more likely to get
 in the way of the physician's line of sight to the portion of the body
 being monitored.
 As shown in FIG. 1B, the second stem portion 106 is, in the illustrated
 embodiment, merged with the first stem portion 104 so that the second stem
 portion 106 extends along a longitudinal axis 114. The longitudinal axis
 114 of the second stem portion preferably forms an inclined angle 116 with
 respect to the longitudinal axis 110 of the first stem portion, as shown
 in FIG. 1B. This relationship between the first and second stem portions
 104, 106 permits the physician using the probe to more accurately
 determine the position of the probe relative to the anatomical structure
 being monitored than if only a first stem portion were present.
 Specifically, the inclined angle 116 permits the physician to accurately
 maintain the orientation of the probe while viewing, for example, a
 monitor displaying an output from the probe. The angulation of the second
 stem portion 106 also allows the physician to hold the probe, at least in
 part, by the second stem portion 106 without placing his or her fingers in
 the line of sight to the base of the probe.
 Turning now to FIGS. 1C, 2 and 3, FIG. 1C presents the base 102 of the
 housing 100, including the longitudinal axis of the base 108, the lateral
 axis of the base 118, and the plane 120 in which the longitudinal and
 lateral axes may reside. FIG. 2 illustrates the inclined plane 200 in
 which the first and second stem portions 104, 106 may reside. Also
 presented are the line of intersection 202 of these two planes, the angle
 of intersection 204 of these two planes, and the longitudinal axis of the
 second stem portion 205 (which, in FIG. 2, resides in the inclined plane
 200). FIG. 3 presents the planes in which the axes of the base 120, first
 stem portion 300, and second stem portion 302 may reside.
 As shown in FIG. 1C, the base 102 may be constructed such that the lateral
 118 and longitudinal 108 axes of the base reside in a first plane 120.
 Preferably, the first stem axis 104 extends from the base in a second
 plane 300, shown in FIG. 3, that is substantially perpendicular to the
 first plane 120, in which the axes of the base 108, 118 reside. This
 perpendicular relationship between the planes 120, 300 permits the probe
 to be used in a manner that will cause minimal agitation, including
 tearing, to an incised portion of the tissue during, for example,
 intraoperative use, as can be seen from FIG. 6.
 In the preferred construction, the second stem portion 106 resides in a
 third plane 302 that forms an inclined angle 304 with the first plane and
 an inclined angle 306 with the second plane, as shown in FIG. 3. That is,
 the second stem portion 106 preferably extends, at least in part,
 laterally away from the second plane 300 while it extends, at least in
 part, vertically away from the base 102 of the probe.
 In the embodiment illustrated in FIG. 2, the first and second stem portions
 104, 106 lie in an inclined plane 200 with respect to the plane 120 in
 which the longitudinal and lateral axis of the base reside. The inclined
 plane 200 intersects the first plane 120 along a line 202 parallel to the
 lateral axis of the base. That is, the first and second stem portions 104,
 106 in this embodiment gradually move away from the base at a constant,
 inclined angle 202, even after the transition from the first stem portion
 104 to the second stem portion 106 (shown by angle 116).
 Turning now to FIGS. 4 and 5, those Figures present a probe and handle
 housing 400 including a base 102 and a handle 402 according to another
 embodiment of the invention. The illustrated base 102 is elongated and has
 longitudinal 108 and lateral 118 axes. The handle 402 of the housing 400
 has a proximal end 404 and a distal end 406. The proximal end 404 of the
 handle is coupled to the base 102. The distal end 406 of the handle,
 however, extends away from the base 102 in a lateral direction with
 respect to the longitudinal axis 108 of the base. In the illustrated
 embodiment, the handle 402 is curvilinear in shape and, in fact, forms a
 continuous curvilinear profile.
 As with a previously-referenced embodiment, this shape permits the
 physician to be able to more accurately determine where the probe is
 positioned relative to the anatomical structure being imaged.
 Specifically, if the physician grips the handle 402 near the distal end
 406, the physician may have an unobstructed view of the proximal end 404
 of the handle and, more importantly, of the base 102 of the probe.
 Additionally, in the illustrated embodiment of FIG. 5, the handle 402 has
 a substantially hollow interior 500. The substantially hollow interior 500
 permits, for example, the multifilament cable shown in FIG. 5 to lead to a
 connector suitable for connecting the probe to an ultrasonic diagnostic
 system which drives the transducer of the probe and receives ultrasonic
 echo signals from the transducer. The probe cable 107 shown in FIG. 1 may
 be provided, for example, to contain the multifilament cable.
 Preferably, the distal end 406 of the handle extends away from the base 102
 at an inclined angle with respect to the base 102. When the probe is used
 intraoperatively, this shape permits the physician to more easily grip the
 handle 402 of the probe without agitating or interfering with the incised
 area of the patient. The probe may also be formed such that the proximal
 end 404 of the handle extends away from the base 102 at an inclined angle
 with respect to the base. Preferably, both the proximal 404 and distal 406
 ends extend away from the base at an inclined angle. This preferred
 structure permits as short of a handle 402 as possible while still
 allowing the physician to properly grip the handle 402 without obstructing
 the physician's view of the probe.
 In the illustrated embodiment of FIG. 4, the longitudinal and lateral axes
 108, 118 of the base reside in a first plane 120. The proximal end 404
 initially extends from the base 102 in a second plane 300 that is
 approximately perpendicular to the first plane, as shown in FIG. 3. When
 used intraoperatively, this illustrated structure permits the handle to
 extend from the probe in a manner causing minimal agitation of the incised
 area of the patient, similarly to the embodiment shown in FIG. 6. In the
 illustrated embodiment, the distal end 406 of the handle lies in an
 inclined plane that intersects the first plane along a line of
 intersection that is parallel to the lateral axis of the base; for
 example, the inclined plane 200 shown in FIG. 2.
 In the present embodiment, the handle 402 may be formed by multiple handle
 portions, such as the first 700 and second 702 handle portions of FIG. 7,
 that intersect at an obtuse angle 704. As a result, it can be seen that a
 handle 402 according to the present invention may be partially curved in
 shape and partially straight.
 According to yet another embodiment of the invention, whichever of the
 aforementioned configurations is used, a cushion 800 may be removably
 affixed to the base 102, as shown in FIG. 8. The cushion 800 may be
 adapted to contain a fluid 802. The fluid 802 contained within the cushion
 800 may be composed of a material having a similar sound velocity to
 anatomical tissue, thereby permitting the ultrasound probe to obtain a
 better image of the anatomical structure sought to be imaged. Other
 purposes for the cushion 800 of the present invention will be further
 discussed below. First, the cushion 800 provides acts as a "pillow"
 because it provides a damping effect between a pulsing anatomical
 structure and the probe. The pulsing may be caused by, for example, blood
 pulsation. Second, the cushion 800 improves the acoustic coupling between
 a fixed (usually flat) surface of a probe and an often curved and/or
 irregularly shaped anatomical structure, such as a heart, artery, or other
 organ. The cushion 800, with the fluid 802 contained therein, is
 preferably pliable so that the damping and coupling can be effected.
 The cushion 800 shown in FIG. 8 is balloon-shaped, having a neck portion
 804 and a bag portion 806. Although this shape is not required, when the
 cushion 800 is so shaped, the neck portion 804 may be removably affixed to
 the base. In the illustrated embodiment of FIG. 8, the inner perimeter of
 the neck portion 804 receives the lower surface of the base 102.
 Preferably, a substantially fluid-impermeable seal is formed where the
 neck portion 804 is removably affixed to the base 102. Additionally, in
 the illustrated embodiment, it is the bag portion 806 of the cushion 800
 that is adapted to contain a fluid 802.
 Whichever of the embodiments is used, however, the handle may also be
 constructed so that it does not have a substantially hollow interior. The
 probe cable 107 may exit the handle closer to the base 102 than
 illustrated in FIG. 1. Alternatively, the probe cable 107 may exit the
 base 102 separately from the handle (not pictured). The handle may also be
 removably affixed to the base 102, so that the handle can be detached from
 the base 102. Moreover, the handle may be formed such that it is flexible
 and bendable to a user desired shape.
 FIG. 9 illustrates a perspective view of an ultrasonic probe 900 having a
 base member 902 with an undersurface 903 which houses an ultrasonic
 transducer 1702 (as illustrated in FIG. 17), and a pliable cushion 904
 according to an alternative embodiment of the present invention. The base
 member 902 is elongated and includes four sidewalls 905. The sidewalls 905
 include a groove 906 extending horizontally around the perimeter of the
 base member 902. The groove 906 is located at an intermediate section of
 the base member 902, for example approximately one-half way between the
 undersurface 903 and the top of the base member 902. The perimeter of the
 illustrated sidewalls 905 is substantially rectangular in shape. FIG. 10
 discloses a side view of the probe 900 and cushion 904. FIG. 11 discloses
 a front view of the probe 900. As shown in FIG. 11, the groove 906 may be
 a square groove, formed at right angles with respect to the probe base
 member sidewalls 905.
 The illustrated cushion 904 or pad includes a flexible bag portion 908, a
 neck portion 910, and includes an interior cavity 911. In the preferred
 embodiment, the cushion 904 includes an elastic member, for example an
 elastic band 912 as shown in FIG. 9, attached to the neck portion 910 of
 the cushion 904. The cushion 904 shown in FIG. 9 also includes an
 undersurface 913 and an aperture 914 through the neck portion 910. FIG. 9
 also illustrates an optional fluid receptacle 916 and an inner surface 918
 of the cushion 904.
 In order to use the ultrasonic probe 900 with the cushion 904, the cushion
 904 is filled with a fluid, for example through the aperture 914.
 Optionally, the cushion 904 may be filled through a resealable fluid
 receptacle 916 which may allow a needle or similar object to penetrate the
 cushion 904 to fill the cushion 904 with an acoustic coupling fluid 802.
 Optionally, the cushion 904 may be filled with a fluid 802 through a
 tunnel 1002, in the base member 902 and/or other portions of the probe
 900, having a receptacle 1004 at one end of the tunnel 1002 for insertion
 of a fluid, as shown in FIG. 10. In this alternative embodiment, the base
 member 902 includes on its undersurface 903 an aperture 1006 at the
 opposite end of the tunnel 1002 for transmitting a fluid 802 to the
 cushion 904. Optionally, the cushion 904 may be manufactured and shipped
 containing the fluid 802 and having a peel-away cover 1502 that may be
 removed prior to use to permit the pad 904 to be secured to the base
 member 902, as shown in FIG. 15.
 Either before or after the cushion 904 is filled with a fluid 802, the pad
 904 is secured to the base member 902 by placing the transducer of the
 probe 900 through the aperture 914 in contact with the fluid. The elastic
 band 912 is inserted into the groove 906, as shown in FIGS. 10 and 17.
 Optionally, the cushion 904 may be secured to the base member 902 by
 alternate means, for example by tying, clamping or strapping the cushion
 904 to the base member 902. For example, as shown in FIG. 13, the cushion
 904 is strapped to the probe 900 by one or more straps 1302. In the
 embodiment illustrated by FIG. 13, the cushion 904 may also be equipped
 with an additional device for maintaining a fluid-impermeable seal with
 the base member 902. Optionally, the cushion 904 may be made from an
 elastic material and the cushion 904 may be secured to the probe 900
 simply by stretching the neck portion 910 of the pad 904 around the base
 member 902, as shown in FIG. 8. Optionally, the sidewalls 905 of the base
 member 902 may be shaped to form a trapezoid, step or other structure for
 securing the cushion 902 to the probe 900. FIG. 18 illustrates a
 trapezoidal shaped base member 1802, which includes an upper cross-section
 .alpha. and a lower long cross-section .beta. to assist in retaining a
 cushion 904 to the base member 902. FIG. 19 illustrates a square step 1902
 along the base of the sidewall 902 to assist in retaining a cushion 904 to
 the base member 902.
 The cushion 904 may be made of any one or more of a number of pliable
 materials. Preferably, the material should be able to retain a fluid and
 be able to stretch to fit around the perimeter of the base member. The
 material preferably has acoustical qualities such that it does not
 substantially interfere with the transmitted and received ultrasonic
 waves. Exemplary materials include latex, vinyl, nitrile and
 ELASTYREN.RTM.. ELASTYREN.RTM. is a substitute for latex for those who are
 allergic to latex and is manufactured by ECI Medical Technologies, Inc. in
 Bridgewater, Nova Scotia, Canada.
 The cushion 904 may be removably affixed to the base, as shown in FIGS. 8,
 10 and 11. A fluid compartment 908 is created between the bottom surface
 903 of the base member 902 and the inner surface 918 of the cushion 904.
 Optionally, the cushion 904 may envelop the entire base member 902 and a
 portion of the stem, as shown in FIG. 14. The cushion 904 may be secured
 to the probe stem by using a strap 1402, for example a VELCRO.RTM. strap.
 Preferably, the fluid contained within the cushion 904 is composed of a
 material having a similar sound velocity to anatomical tissue (or at least
 a sound velocity that does not adversely affect the ultrasonic waves).
 This permits the ultrasound probe 900 to obtain a better image of the
 anatomical structure sought to be imaged. The illustrated cushion 904 can
 be filled with sterile water or a gel. Sterile water is preferred because
 the preferred cushion 904, when filled immediately prior to usage, does
 not need to be shipped and stored while containing a fluid (and therefore
 is not susceptible to evaporation). The use of water instead of gel is
 beneficial because water has a sound velocity that is more similar to
 anatomical tissue than are gels.
 During use, the cushion 904 acts as a pillow or cushion to dampen forces
 and motion external to the probe, such as during intraoperative use. Such
 external forces may include pulsing anatomical structures, for example the
 heart, other organs or other tissue related to the pressure side of the
 blood system. External forces or motion may also include motion during
 muscle activation. The cushion 904 also improves the acoustical coupling
 between a fixed surface of the base member 902 and an often curved and/or
 irregularly shaped anatomical structure, such as a heart, artery, or other
 organ. Specifically, the cushion 904 conforms to the shape of the
 anatomical tissue, thereby eliminating air pockets between the probe 900
 and tissue and improving the ultrasound image quality. Without the pliable
 cushion 904, the rigid undersurface 903 of the illustrated base member 902
 might deform the organ and/or its blood flow when pressed against the
 organ, thereby adversely affecting ultrasound image quality. For this
 reason, the cushion 904, with the fluid 802 contained therein, is
 preferably pliable so that the damping and coupling can be effected.
 During use, the undersurface 913 of the cushion 904 may contact the
 anatomic structure sought to be imaged. The pliable cushion 904 will
 deform according to the pressure placed on the pad by the organ, thus
 compensating for the movement of the organ and the probe 900 while still
 obtaining an acoustic coupling for the ultrasound energy.
 The cushion 904 shown in FIGS. 8, 9 and 10 is balloon-shaped, having a neck
 portion 910 and a bag portion 908. Although this shape is not required,
 when the cushion 904 is so shaped, the neck portion 910 may be removably
 affixed to the base 902, for example as discussed above. In the
 illustrated embodiment of FIG. 8, the inner perimeter of the neck portion
 910 receives the lower surface of the base 902, and thus no elastic member
 is needed. Preferably, a substantially fluid-impermeable seal is formed
 where the neck portion 910 is removably affixed to the base 902,
 regardless of whether an elastic member is used. Additionally, in the
 illustrated embodiment of FIG. 8, it is the bag portion of the cushion pad
 904 that is adapted to contain a fluid 802. Optionally, the cushion 904
 may contain a sealing member 1602 on the interior 911 of the cushion 904
 below the neck portion 910 of the cushion 904. If a sealing member 1602 is
 used, the undersurface 903 of the base member 902 is preferably placed in
 direct contact with the sealing member 1602 during use (to avoid the
 existence of air pockets between the base member 902 and the anatomic
 structure).
 Turning now to FIG. 12, that Figure presents an alternative embodiment of
 an ultrasound probe 1200 wherein the base member 1201 includes a ridge
 1202 for securing a cushion 904 to the base member 1201. The ridge 1202
 may be used for affixation of a pliable cushion 904 having an elastic
 member to the base member 1201. Optionally, a pliable pad may have a rigid
 ring at its neck portion shaped to form a snap fit with the ridge 1202.
 While particular embodiments of the invention have been shown, it will be
 understood, of course, that the invention is not limited thereto since
 modifications may be made by those skilled in the art, particularly in
 light of the foregoing teachings. For example, although the invention is
 at times discussed as being used intraoperatively, the invention is not
 limited to intraoperative probes. Moreover, although the invention is
 shown in FIGS. 9-11 as having a multi-angled handle, the one of many
 different types of handles invention is not limited thereto since it may
 be used with an ultrasound probe having one of many type of handle, for
 example as indicated in FIGS. 8 and 12. It is, therefore, contemplated
 that the appended claims will cover any such modifications as incorporate
 those features which constitute the essential features of these
 improvements within the true spirit and the scope of the invention.