Patent Description:
Ultrasonic transducers have been employed in ultrasound therapy systems to achieve therapeutic heating of diseased and other tissues. Arrays of ultrasound transducers operating to form a beam of ultrasonic energy cause a conversion of sound to thermal energy in the affected tissue areas or treatment volumes, and a subsequent beneficial rise in the temperature in the treatment volumes.

In image-guided ultrasound therapy systems, a patient and the ultrasound therapy apparatus, including an ultrasound positioning apparatus, are generally disposed in an imaging volume such as a magnetic resonance imaging (MRI) apparatus, which allows guidance of the applicator placement, and in addition allows monitoring of the treatment effect on the tissue by providing real-time data from which temperature maps can be calculated. A clinical operator can then monitor the progress of the therapy within the treatment volume or diseased tissue and manual or automated changes can be made to the ultrasound power signals based on input from the results and progress of the treatment. With proper monitoring of the heating effect, ultrasound therapy systems can be used to treat harmful cells and to controllably destroy tumors while minimizing damage to healthy tissue. <CIT> describes a device for acoustic coupling, temperature regulation, and immobilization of patient during focused ultrasound therapy. <CIT> and <CIT> also disclose a high-intensity focused ultrasound therapy system with cooling.

Example embodiments described herein have innovative features, no single one of which is indispensable or solely responsible for their desirable attributes. The following description and drawings set forth certain illustrative implementations of the disclosure in detail, which are indicative of several exemplary ways in which the various principles of the disclosure may be carried out. The illustrative examples, however, are not exhaustive of the many possible embodiments of the disclosure. Without limiting the scope of the claims, some of the advantageous features will now be summarized. Other objects, advantages and novel features of the disclosure will be set forth in the following detailed description of the disclosure when considered in conjunction with the drawings, which are intended to illustrate, not limit, the invention as defined by the appended claims.

An aspect of the invention is directed to a convertible patient support apparatus comprising a patient support bed having a hole defined therein; a support frame disposed on or in the hole, the support frame attached to the patient support bed; and a static membrane fixedly attached to the support frame. The convertible patient support apparatus further comprises a removable patient contact including: an interface frame removably attached to the support frame; a patient contact frame fixedly attached to the interface frame; and a patient contact membrane fixedly attached to the interface frame. The patient contact membrane, the static membrane, and the interface frame define a cavity, the cavity having a port to introduce or remove an ultrasound coupling and cooling fluid to or from the cavity.

In one or more embodiments, the static membrane is disposed below the removable patient contact. In one or more embodiments, the static membrane is rigid. In one or more embodiments, the patient contact membrane is deformable.

In one or more embodiments, the port comprises an inlet port, an internal fluid circulation channel is formed between the patient contact frame, the static membrane, and the support frame, and the internal fluid circulation channel provides the ultrasound coupling and cooling fluid to the cavity through the inlet port and receives the ultrasound coupling and cooling fluid from the cavity through the outlet port. In one or more embodiments, the apparatus further comprises an ultrasound coupling and cooling fluid recirculation system; an outlet channel that fluidly couples the outlet port to an input of the ultrasound coupling and cooling fluid recirculation system; and an input channel that fluidly couples an output of the ultrasound coupling and cooling fluid recirculation system to the internal fluid circulation channel. In one or more embodiments, the ultrasound coupling and cooling fluid recirculation system comprises a tank, a pump, a fluid chiller, and a degasser.

In one or more embodiments, the apparatus further comprises mechanical locks that releasably securely attach the interface frame to the support frame.

Another aspect of the invention is directed to a convertible patient support apparatus comprising a patient support bed having a hole defined therein; a support frame disposed on or in the hole, the support frame attached to the patient support bed; and a static membrane fixedly attached to the support frame. The apparatus further comprises a removable patient contact comprising: an interface frame removably attached to the support frame; a patient contact frame fixedly attached to the interface frame; a patient contact membrane fixedly attached to the interface frame; a raised rigid patient contact attached to the patient contact frame, the raised rigid patient contact disposed between the patient contact membrane and the static membrane; and a plurality of circulation channels disposed on or in the raised rigid patient contact. An internal fluid circulation channel is formed between the patient contact frame, the static membrane, and the support frame. The circulation channels are fluidly coupled to one or more inlet ports in the internal fluid circulation channel to receive the ultrasound coupling and cooling fluid. In addition, the circulation channels are fluidly coupled to one or more outlet ports in the internal fluid circulation channel to output the ultrasound coupling and cooling fluid.

In one or more embodiments, the raised rigid patient contact is configured to engage an anatomical structure of a patient during an ultrasound therapeutic treatment when the patient is on the patient support bed. In one or more embodiments, the circulation channels extend parallel to each other.

In one or more embodiments, the circulation channels form a spiral. In one or more embodiments, an output channel is formed through the spiral to receive the ultrasound coupling and cooling fluid from a termination of the circulation channels. In one or more embodiments, the output channel is fluidly coupled to the one or more outlet ports in the internal fluid circulation channel. In one or more embodiments, the output channel is fluidly coupled to an ultrasound coupling and cooling fluid recirculation system. In one or more embodiments, the ultrasound coupling and cooling fluid recirculation system comprises a tank, a pump, a fluid chiller, and a degasser.

Yet another aspect of the invention is directed to a kit comprising a convertible patient apparatus and a plurality of removable patient contacts. The convertible patient apparatus comprises a patient support bed having a hole defined therein; a support frame disposed on or in the hole, the support frame attached to the patient support bed; and a static membrane fixedly attached to the support frame. Each removable patient contact includes an interface frame configured to be removably attached to the support frame; a patient contact frame fixedly attached to the interface frame; and a patient contact membrane fixedly attached to the patient contact frame. When the interface frame of one of the removable patient contacts is attached to the support frame to form an attached patient contact, an internal fluid circulation channel is formed between the patient contact frame of the attached patient contact, the static membrane, and the support frame.

In one or more embodiments, the plurality of removable patient contacts includes a first removable patient contact, and when the first removable patient contact is attached to the support frame, the patient contact membrane and the static membrane define a cavity having a port that is fluidly coupled to the internal fluid circulation channel to introduce or remove an ultrasound coupling and cooling fluid to or from the cavity. In one or more embodiments, when the first removable patient contact is attached to the support frame: the port comprises an inlet port, the cavity has an outlet port that is fluidly coupled to the internal fluid circulation channel, and the cavity receives the ultrasound coupling and cooling fluid from the inlet port and outputs the ultrasound coupling and cooling fluid through the outlet port. In one or more embodiments, the internal fluid circulation channel is fluidly coupled to an ultrasound coupling and cooling fluid recirculation system. In one or more embodiments, the ultrasound coupling and cooling fluid recirculation system comprises a tank, a pump, a fluid chiller, and a degasser.

In one or more embodiments, when the first removable patient contact is attached to the support frame, the static membrane is disposed below the first removable patient contact. In one or more embodiments, the patient contact membrane of the first removable patient contact is deformable.

In one or more embodiments, the plurality of removable patient contacts includes a second removable patient contact. In the second removable patient contact: a raised rigid patient contact is attached to the patient contact frame; a plurality of circulation channels are disposed on or in the raised rigid patient contact, the circulation channels configured to receive the ultrasound coupling and cooling fluid from one or more inlet ports in the internal fluid circulation channel to output the ultrasound coupling and cooling fluid to one or more outlet ports in the internal fluid circulation channel; and when the second removable patient contact is attached to the support frame, the raised rigid patient contact of the second removable patient contact is disposed between the patient contact membrane and the static membrane.

In one or more embodiments, the raised rigid patient contact is configured to engage an anatomical structure of a patient during an ultrasound therapeutic treatment when the patient is on the patient support bed, and the second removable patient contact is attached to the support frame. In one or more embodiments, the circulation channels, disposed on or in the raised rigid patient contact, extend parallel to each other. In one or more embodiments, the circulation channels, disposed on or in the raised rigid patient contact, form a spiral. In one or more embodiments, an output channel is formed through the spiral to receive the ultrasound coupling and cooling fluid from a termination of the circulation channels.

In one or more embodiments, the output channel is fluidly coupled to the one or more outlet ports in the internal fluid circulation channel. In one or more embodiments, the output channel is fluidly coupled to an ultrasound coupling and cooling fluid recirculation system. In one or more embodiments, the ultrasound coupling and cooling fluid recirculation system comprises a tank, a pump, a fluid chiller, and a degasser.

In one or more embodiments, the plurality of removable patient contacts includes a third removable patient contact. In the third removable patient contact: the patient contact membrane is rigid; the patient contact membrane, the static membrane, and the interface frame define a cavity having an inlet port and an outlet port that are fluidly coupled to the internal fluid circulation channel; and the cavity receives the ultrasound coupling and cooling fluid from the inlet port in the circulation frame and outputs the ultrasound coupling and cooling fluid through the outlet port.

In one or more embodiments, the kit further comprises mechanical locks that releasably securely attach the interface frame of each removable patient contact to the support frame. In one or more embodiments, the static membrane is rigid.

Another aspect of the invention is directed to a system comprising a convertible patient support and a high intensity focused ultrasound (HIFU) system for sonicating a sonication volume of a patient. The convertible patient support comprises: a patient support bed having a hole defined therein; a support frame disposed on or in the hole, the support frame attached to the patient support bed; a static membrane fixedly attached to the support frame; and a removable patient contact. The removable patient contact comprises: an interface frame removably attached to the support frame; a patient contact frame fixedly attached to the interface frame; and a patient contact membrane fixedly attached to the interface frame. The patient contact membrane, the static membrane, and the interface frame define a cavity, the cavity having a port to introduce or remove an ultrasound coupling and cooling fluid to or from the cavity. The HIFU system includes an ultrasound applicator disposed below the hole in the patient support bed, the ultrasound applicator generating ultrasound energy having a path through the static membrane, the ultrasound coupling and cooling fluid, and the patient contact membrane to reach a target volume in the patient.

In one or more embodiments, the path of the ultrasound energy does not include any structures that are opaque to ultrasound energy transmission.

In one or more embodiments, the port comprises an inlet port, an internal fluid circulation channel is formed between the patient contact frame, the static membrane, and the support frame, and the internal fluid circulation channel provides the ultrasound coupling and cooling fluid to the cavity through the inlet port and receives the ultrasound coupling and cooling fluid from the cavity through the outlet port.

In one or more embodiments, an internal fluid circulation channel is formed between the patient contact frame, the static membrane, and the support frame, the internal fluid circulation channel providing the ultrasound coupling and cooling fluid to the cavity through the inlet port and receiving the ultrasound coupling and cooling fluid from the cavity through the outlet port.

In one or more embodiments, the system further comprises: an ultrasound coupling and cooling fluid recirculation system; an outlet channel that fluidly couples the outlet port to an input of the ultrasound coupling and cooling fluid recirculation system; and an input channel that fluidly couples an output of the ultrasound coupling and cooling fluid recirculation system to the internal fluid circulation channel. In one or more embodiments, the ultrasound coupling and cooling fluid recirculation system comprises a tank, a pump, a fluid chiller, and a degasser.

For a fuller understanding of the nature and advantages of the present concepts, reference is made to the detailed description of preferred embodiments in connection with the accompanying drawings.

A convertible patient support apparatus includes a patient support bed and a removable patient contact disposed in a hole in the patient support bed. The hole is defined by a support frame. A static membrane is attached to the support frame. A plurality of removable patient contacts can be provided to convert the convertible patient support apparatus based on the patient and/or therapy.

Each patient contact includes an interface frame, a patient contact frame, and a patient contact membrane attached to the patient contact frame. An internal fluid circulation channel is formed between the support frame, the patient contact frame, and the static membrane. The internal fluid circulation channel is configured to circulate ultrasound coupling and cooling fluid in the patient contact.

In one embodiment, the patient contact membrane, the static membrane, and the interface frame form a cavity that is fluidly coupled to the internal fluid circulation channel such that the ultrasound coupling and cooling fluid can flow into and out of the cavity. The patient contact membrane can be rigid such that it maintains it shape when it contacts and receives a force from a patient during use. Alternatively, the patient contact membrane can be deformable such that it deforms in response to contact and force from a patient during use.

In another embodiment, the patient contact membrane is deformable and a raised rigid patient contact is disposed between the deformable patient contact membrane and the static membrane. The raised rigid patient contact can be configured to engage an anatomical structure of a patient during ultrasound therapeutic treatment when the patient is on the patient support bed. A plurality of ultrasound coupling and cooling fluid channels can be defined on or in the raised rigid patient contact.

<FIG> is a diagram of one type of a medical system <NUM> in which at least some of the apparatus, systems, and/or methods disclosed herein are employed, in accordance with at least some embodiments. The system <NUM> includes a patient support <NUM> for a patient <NUM>, a magnetic resonance imaging system <NUM>, and an image-guided HIFU system <NUM>.

The magnetic resonance imaging system <NUM> includes a magnet <NUM> disposed about an opening <NUM>, an imaging zone <NUM> in which the magnetic field is strong and uniform enough to perform magnetic resonance imaging, a set of magnetic field gradient coils <NUM> to change the magnetic field rapidly to enable the spatial coding of MRI signals, a magnetic field gradient coil power supply <NUM> that supplies current to the magnetic field gradient coils <NUM> and is controlled as a function of time, a transmit/receive coil <NUM> (also known as a "body" coil) to manipulate the orientations of magnetic spins within the imaging zone <NUM>, a radio frequency transceiver <NUM> connected to the transmit/receive coil <NUM>, and a computer <NUM>. The computer <NUM> includes a hardware-based processor that executes computer-readable instructions (e.g., stored on a non-transitory storage medium operatively coupled to the computer <NUM>) to perform tasks to facilitate operation of the MRI system <NUM>. In addition, the computer <NUM> is coupled to the radio frequency transceiver <NUM>, the magnetic field gradient coil power supply <NUM>, and the image-guided energy delivery system <NUM>.

The HIFU system <NUM> includes a therapeutic applicator comprising an array of ultrasonic transducer elements to perform image-guided thermal therapy (e.g., ultrasound therapy) in multiple angular directions to treat a target treatment region. The array of ultrasonic transducer elements are configured and arranged to have a geometric focus <NUM> that can be electronically steered by adjusting the relative phase of the ultrasound energy generated by each ultrasonic transducer element. The HIFU system <NUM> is imaged-guided to treat a target treatment region <NUM> in the patient <NUM>.

The MRI computer <NUM> can include more than one computer in some embodiments, which can be dedicated for the MRI system <NUM>. In at least some embodiments, the MRI computer <NUM> and/or one or more other computing devices (not shown) in and/or coupled to the system <NUM> may also perform one or more tasks (e.g., by executing computer-readable instructions stored on a non-transitory storage medium) to implement one or more aspects and/or embodiments disclosed herein (or portion(s) thereof) to determine the thickness of subcutaneous fat between the therapeutic applicator and the target treatment region and to adjust one or more treatment parameters based on the subcutaneous fat thickness.

One or more of the computers, including computer <NUM>, can include a treatment plan for the patient <NUM> that includes the target treatment region and the desired or minimal energy (e.g., thermal) dose for the target treatment region. The computer(s) can use images from the magnetic resonance imaging system <NUM> to image guide the therapeutic applicator (e.g., position and angular orientation). Some or all of the foregoing computers can be in communication with one another (e.g., over a local area network, a wide area network, a cellular network, a WiFi network, or other network), for example through a software-controlled link to a communication network.

<FIG> is a perspective view of a convertible patient support <NUM> according to an embodiment. The convertible patient support <NUM> can be the same as patient support <NUM>. The convertible patient support <NUM> includes a patient support bed <NUM> and a removable patient contact <NUM>. The removable patient contact <NUM> is disposed in a hole <NUM> defined in the patient support bed <NUM>.

A support frame <NUM> is disposed around or proximal to the perimeter of the hole <NUM>. The support frame <NUM> is attached to the patient support bed <NUM>. For example, the support frame <NUM> can be attached to a top surface <NUM> of the patient support bed <NUM>. The top surface <NUM> can be a planar surface or a generally planar surface on which a patient (e.g., patient <NUM>) lies during ultrasound therapeutic treatment. Additionally or alternatively, the support frame <NUM> can be attached to an inner surface of the patient support bed <NUM> that defines the hole <NUM>. In either case, the support frame <NUM> can be directly attached to the respective surface or indirectly attached to the respective surface (e.g., the support frame <NUM> can be attached to an underlying structure that is directly attached to the surface).

The removable patient contact <NUM> includes optional mechanical locks <NUM>, a patient contact membrane <NUM>, the interface frame <NUM>, and a patient contact frame <NUM>.

The mechanical locks <NUM> (e.g., a mechanical locking mechanism) releasably attach the removable patient contact <NUM> to the support frame <NUM>. The mechanical locks <NUM> include a slideable structure that can slide in a first direction to engage a complementary structure in the underlying support frame <NUM> to secure the removable patient contact <NUM> relative to the support frame <NUM>. The slideable structure can slide in a second direction, opposite to the first direction, to disengage the complementary structure in the underlying support frame <NUM> to unlock the removable patient contact <NUM> from the support frame <NUM>. The slideable structure can include a rod, a projection, a fin, or other structure. The complementary structure can include a groove, recess, or other complementary structure. Alternatively, the mechanical locks <NUM> can include a rotatable structure (e.g., as in a window sash lock), a latch, or other structure. Or the top frame structure could accommodate a rotational lock mechanism such as bayonet lock or threaded lid.

The patient contact membrane <NUM> is attached to (e.g., fixedly attached to) the patient contact frame <NUM>. The patient contact membrane <NUM> contacts the patient's skin proximal to the target treatment region during ultrasound therapeutic treatment. The patient contact membrane <NUM> encloses and contains the ultrasound coupling and cooling fluid that circulates in the removable patient contact <NUM> below. The membrane is constructed in such a way that it can transmit ultrasound from an ultrasound device (e.g. image-guided HIFU system <NUM>) to the patient, and also conduct heat energy away from the patient.

The patient contact membrane <NUM> can be rigid or deformable. When the patient contact membrane <NUM> is rigid, the patient contact membrane <NUM> (e.g., the exposed patient contact surface <NUM> of the patient contact membrane <NUM>) maintains a predetermined shape when the patient applies a force thereto, such as by laying on the patient support bed <NUM> or placing a limb on the removable patient contact <NUM>. The predetermined shape of the patient contact membrane <NUM> can be planar (e.g., as illustrated in <FIG>) or non-planar. Examples of non-planar patient contact membrane surfaces includes one or more raised planar regions (e.g., plateaus) that can be configured to engage an anatomical feature in the patient during ultrasound therapeutic treatment. The rigid patient contact membrane <NUM> can comprise an ultrasound gel pad.

When the patient contact membrane <NUM> is deformable, the patient contact membrane <NUM> (e.g., the exposed patient contact surface <NUM> of the patient contact membrane <NUM>) deforms when the patient applies a force thereto, such as by laying on the patient support bed <NUM> or placing a limb on the removable patient contact <NUM>. For example, the patient contact membrane can conform, partially or fully, to the patient's body (e.g., similar to a water bed). The deformable patient contact membrane can comprise a thermoplastic elastomer (TPE).

<FIG> is a perspective view of a convertible patient support <NUM> according to an embodiment. Convertible patient support <NUM> is identical to convertible patient support <NUM> except that the removable patient contact <NUM> in convertible patient support <NUM> includes a deformable patient contact membrane <NUM> instead of the patient contact membrane <NUM>.

<FIG> is a cross-sectional view of convertible patient support <NUM> through line <NUM>-<NUM> in <FIG>. The cross-section view of convertible patient support <NUM> is representative of the cross-section view of convertible patient support <NUM> except that the removable patient contact <NUM> in convertible patient support <NUM> includes a deformable patient contact membrane <NUM> instead of the patient contact membrane <NUM>.

The cross-sectional view illustrates that the convertible patient support <NUM> includes a static or fixed membrane <NUM> (in general, static membrane <NUM>) and a patient contact frame <NUM>. The static membrane <NUM> can comprise BoPET (biaxially-oriented polyethylene terephthalate) (e.g., MYLAR® available from DuPont Teijin Films). The static membrane <NUM> is attached (e.g., fixedly attached) to the support frame <NUM>, which is attached (e.g., fixedly attached) to the patient support bed <NUM>. The removable patient contact <NUM> includes the interface frame <NUM>, the patient contact frame <NUM>, and the deformable patient contact membrane <NUM>. The interface frame <NUM> is attached (e.g., fixedly attached) to the patient contact frame <NUM>, which is attached (e.g., fixedly attached) to the deformable patient contact membrane <NUM>. Optional mechanical locks <NUM> on the interface frame <NUM> can releasably secure the interface frame <NUM> (and thus the removably patient contact <NUM>) to the support frame <NUM>. Thus, the patient contact frame <NUM> is indirectly attached to the support frame <NUM>.

In some embodiments, the interface frame <NUM> is optional in which case the patient contact frame <NUM> is removably attached to the support frame <NUM>.

A cavity <NUM> is formed between the deformable patient contact membrane <NUM>, the static membrane <NUM>, and the interface frame <NUM>. The cavity <NUM> is in fluid communication with one or a plurality of inlet port(s) <NUM> in the cavity <NUM> to receive an ultrasound coupling and cooling fluid (e.g., water) from an internal fluid circulation channel <NUM>. In some embodiments, the internal fluid circulation channel <NUM> and the optional plurality of inlet ports <NUM> can function as a manifold. The internal fluid circulation channel <NUM> is formed between the support frame <NUM>, the patient contact frame <NUM>, and the static membrane <NUM>. The patient contact frame <NUM> can include gaskets to provide a fluid-tight seal for the internal fluid circulation channel <NUM>. The weight of the convertible patient support <NUM> and the patient laying thereon can improve the fluid-tight seal caused by the gaskets.

The ultrasound coupling and cooling fluid can exit the cavity <NUM> via one or more outlet port(s) <NUM> in the cavity <NUM>. The outlet port(s) <NUM> are fluidly coupled to an outlet channel <NUM> to direct the ultrasound coupling and cooling fluid to an ultrasound coupling and cooling fluid recirculation system <NUM>. Alternatively, in some embodiments the cavity <NUM> can include a single port for introducing and/or receiving the ultrasound coupling and cooling fluid.

The ultrasound coupling and cooling fluid recirculation system <NUM> includes a tank <NUM>, a pump <NUM>, a chiller or heat exchanger <NUM> (e.g., to regulate or control the temperature of the ultrasound coupling and cooling fluid which is heated during circulation), and a degasser <NUM>. The ultrasound coupling and cooling fluid flows out of the cavity <NUM> via the outlet ports <NUM> and an outlet channel <NUM> into the tank <NUM> to transfer heat away from the cavity <NUM> and the patient's skin. A pump <NUM> feeds the heated ultrasound coupling and cooling fluid from the tank <NUM> into a chiller unit <NUM> and a degasser <NUM> where the ultrasound coupling and cooling fluid is cooled and cleared of air bubbles, respectively. After passing through the ultrasound coupling and cooling fluid recirculation system <NUM>, the temperature-controlled ultrasound coupling and cooling fluid is recirculated to the internal fluid circulation channel <NUM> through an input channel <NUM>.

When the ultrasound coupling and cooling fluid fills the cavity <NUM>, the deformable patient contact membrane <NUM> (e.g., including exposed patient contact surface <NUM>) is displaced away from the static membrane <NUM>. When the ultrasound coupling and cooling fluid is removed from the cavity <NUM>, the deformable patient contact membrane <NUM> (e.g., including exposed patient contact surface <NUM>) can deform or bend towards the static membrane <NUM>.

The static membrane <NUM> can have a generally planar surface that faces the cavity <NUM>. The static membrane <NUM> can be attached to the support frame <NUM> using an adhesive or another attachment means. A fluid-tight seal (or a substantially fluid-tight seal) can be formed by the attachment between the static membrane <NUM> and the support frame <NUM>.

During treatment, an ultrasound applicator (e.g., in image-guided HIFU system <NUM>) is placed below the hole <NUM> defined in the patient support bed <NUM>. Ultrasound energy passes through the static membrane <NUM>, the ultrasound coupling and cooling fluid, and the deformable patient contact membrane <NUM> and into the patient where the ultrasound energy is focused on a target volume. The path of the ultrasound energy does not include any structures that are opaque to ultrasound energy transmission.

In addition to providing a path for ultrasound energy to travel, the ultrasound coupling and cooling fluid regulates the temperature of the patient's skin which is heated during treatment. Only a small fraction of the ultrasound energy is conducted through the skin to the target volume. The remaining ultrasound energy is absorbed by the skin tissue, resulting in heating of the skin. This occurs due to density differences in the boundary layer between the skin and the deformable patient contact membrane <NUM>. The energy-conduction ratio decreases significantly if air, which was a much lower density, is able to flow into any gaps in the boundary layer. Therefore, a good skin-membrane boundary layer is desired for a high energy-conduction ratio and to prevent skin burns.

<FIG> is a perspective view of a convertible patient support <NUM> according to an embodiment. Convertible patient support <NUM> is identical to convertible patient support <NUM> except that the removable patient contact <NUM> in convertible patient support <NUM> includes a raised rigid patient contact structure <NUM> disposed between the deformable patient contact membrane <NUM> and the static membrane <NUM>. The raised rigid patient contact structure <NUM> is attached to the patient contact frame <NUM>.

The raised rigid patient contact structure <NUM> has a height that is measured with respect an axis that is orthogonal to the plane defined by a planar portion <NUM> of the raised rigid patient contact structure <NUM>. The top <NUM> of the raised rigid patient contact structure <NUM> is generally planar such that the raised rigid patient contact structure <NUM> forms a plateau. The illustrated plateau is in a teardrop shape. In other embodiments, the plateau can have a heart shape, a round shape (e.g., circle, oval, or other round shape), a rectangular shape, or another shape. Alternatively, the raised rigid contact structure <NUM> can be in the form of a dome. Additionally or alternatively, the raised rigid contact structure <NUM> can be in a form other than a plateau or a dome, or it can include multiple (e.g., <NUM> or more) raised structures.

The teardrop shape illustrated in <FIG> is configured to displace certain patient organs (e.g., stomach and/or liver), not intended for therapy, out of the path of the ultrasound beam when providing therapeutic ultrasound therapy to the target organ (e.g., pancreas). In addition to displacing sensitive organs, the raised rigid patient contact structure <NUM> functions as an ultrasonic coupling medium through which therapeutic ultrasound energy can be transmitted from an ultrasound device (e.g., image-guided HIFU system <NUM>) to the patient.

The deformable patient contact membrane <NUM> is disposed over the raised rigid patient contact structure <NUM> and generally conforms to the shape thereof. For example, in <FIG> the deformable patient contact membrane <NUM> generally conforms to the teardrop shape of the raised rigid patient contact structure <NUM>.

<FIG> is a perspective view of the convertible patient support <NUM> to illustrate a first embodiment of cooling channels <NUM> on the raised rigid patient contact structure <NUM>. The cooling channels <NUM> extend parallel to each other across opposing sides <NUM>, <NUM> of the patient contact frame <NUM>. The cooling channels <NUM> also extend parallel to a central axis <NUM> of the convertible patient support <NUM> (e.g., that extends from a head support to a foot support of the convertible patient support <NUM>).

Each cooling channel <NUM> is preferably fluidly coupled to a respective inlet port on one side of the support frame <NUM> (e.g., to receive the ultrasound coupling and cooling fluid such as water) and to a respective outlet port on the opposing side of the support frame <NUM> (e.g., to output the ultrasound coupling and cooling fluid such as water). For example, each cooling channel <NUM> can be fluidly coupled to a respective inlet port on a first side <NUM> of the support frame <NUM> and to a respective outlet port on a second side <NUM> of the support frame <NUM>. Alternatively, each cooling channel <NUM> can be fluidly coupled to a respective inlet port on the second side <NUM> of the support frame <NUM> and to a respective outlet port on the first side <NUM> of the support frame <NUM>. The inlet and outlet ports are fluidly coupled to the internal fluid circulation channel <NUM>.

In an alternative embodiment, the cooling channels <NUM> can extend parallel to each other across opposing sides <NUM>, <NUM> of the patient contact frame <NUM> and orthogonal to the central axis <NUM>. The cooling channels <NUM> can be fluidly coupled to respective inlet ports on a third side <NUM> of the support frame <NUM> and to respective outlet ports on a fourth side <NUM> of the support frame <NUM>. Alternatively, the cooling channels <NUM> can be fluidly coupled to respective inlet ports on the fourth side <NUM> of the support frame <NUM> and to respective outlet ports on the third side <NUM> of the support frame <NUM>.

<FIG> is a cross-sectional view of convertible patient support <NUM> through line <NUM>-<NUM> in <FIG>. For clarity, the deformable patient contact membrane <NUM> is not illustrated in <FIG>. The convertible patient support <NUM> is fluidly coupled to an ultrasound coupling and cooling fluid recirculation system <NUM>. The ultrasound coupling and cooling fluid flows out of the raised rigid patient contact structure <NUM> via the outlet ports <NUM> and outlet channel <NUM> into the tank <NUM> to transfer heat away from the raised rigid patient contact structure <NUM>. A pump <NUM> feeds the heated ultrasound coupling and cooling fluid from the tank <NUM> into a chiller unit <NUM> and a degasser <NUM> that cool the ultrasound coupling and cooling fluid and remove dissolved gasses from it (e.g., which may form bubbles in the ultrasound coupling and cooling fluid when exposed to negative pressure waves in the ultrasound beam), respectively The ultrasound coupling and cooling fluid is fed via the inlet channel <NUM> into the internal fluid circulation channel <NUM>. Thus, the ultrasound coupling and cooling fluid can flow from a tank or reservoir <NUM>, through one or more inlet channels <NUM> to the internal fluid circulation channel <NUM> (via pump <NUM>), to the inlet ports, then through the cooling channels <NUM>, and out through the outlet ports in the internal fluid circulation channel <NUM>, and back to the tank or reservoir <NUM> via one or more outlet channels <NUM>.

During treatment, an ultrasound applicator (e.g., in image-guided HIFU system <NUM>) is placed below the hole <NUM> defined in the patient support bed <NUM>. Ultrasound energy passes through the static membrane <NUM>, the ultrasound coupling and cooling fluid, the raised rigid patient contact structure <NUM>, and the deformable patient contact membrane <NUM> and into the patient where the ultrasound energy is focused on a target volume. The path of the ultrasound energy does not include any structures that are opaque to ultrasound energy transmission.

<FIG> is a perspective view of convertible patient support <NUM> to illustrate a second embodiment of cooling channels <NUM> on or in the raised rigid patient contact structure <NUM>. For clarity, the deformable patient contact membrane <NUM> is not illustrated in <FIG>. The cooling channels <NUM> extend in a spiral around the raised rigid patient contact structure <NUM>. The illustrated spiral is formed of three cooling channels <NUM>. Additional or fewer cooling channels <NUM> can form the spiral in other embodiments.

The cooling channels <NUM> can be fluidly coupled to one or more inlet ports <NUM> in the internal fluid circulation channel <NUM> (e.g., to receive the ultrasound coupling and cooling fluid). An output hole or channel <NUM> can be formed through the spiral (e.g., through the center of the spiral) to receive the ultrasound coupling and cooling fluid from the termination of the cooling channels <NUM>. The hole or channel <NUM> can be fluidly coupled to the tank <NUM> of the ultrasound coupling and cooling fluid recirculation system <NUM>, such as through outlet channel <NUM>. One or more inlet channels (e.g., inlet channels <NUM>) can fluidly couple the output of the ultrasound coupling and cooling fluid recirculation system <NUM> to the internal fluid circulation channel <NUM>.

It is recognized that the cooling channels <NUM>, <NUM> can have other fluid paths and/or configurations. The paths and configurations <NUM>, <NUM> are provided as non-limiting examples only.

<FIG> is a block diagram of a kit <NUM> according to an embodiment. The kit <NUM> includes a convertible patient support <NUM> and removable patient contacts <NUM>, <NUM>, <NUM>. The convertible patient support <NUM> can be the same as any of the convertible patient supports described herein (e.g., convertible patient support <NUM>, convertible patient support <NUM>, or convertible patient support <NUM>). The convertible patient support <NUM> can include a removable patient contact <NUM> (e.g., removable patient contact <NUM>) or the removable patient contact <NUM> can be removed. In either case, the convertible patient support <NUM> is configured to releasably receive one of a plurality of removable patient contacts <NUM>, <NUM>, <NUM> in a hole <NUM> defined in the convertible patient support <NUM>.

Each removable patient contact <NUM>, <NUM>, <NUM> can be configured the same or different than the others. For example, removable patient contact <NUM> can be the same as described above with respect to <FIG> (e.g., having a patient contact membrane <NUM>). Removable patient contact <NUM> can be the same as described above with respect to <FIG> and <FIG> (e.g., having a deformable patient contact membrane <NUM>). Removable patient contact <NUM> can be the same as described above with respect to any of <FIG> (e.g., having a raised rigid patient contact structure <NUM>).

Claim 1:
A convertible patient support apparatus (<NUM>, <NUM>, <NUM>, <NUM>) comprising:
a patient support bed (<NUM>) having a hole (<NUM>, <NUM>) defined therein; wherein
the convertible patient support apparatus (<NUM>, <NUM>, <NUM>, <NUM>) further comprises:
a support frame (<NUM>) disposed on or in the hole (<NUM>, <NUM>), the support frame (<NUM>) attached to the patient support bed; and
a static membrane (<NUM>) fixedly attached to the support frame (<NUM>); and
a removable patient contact (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) including:
an interface frame (<NUM>) removably attached to the support frame (<NUM>);
a patient contact frame (<NUM>) fixedly attached to the interface frame (<NUM>); and
a patient contact membrane (<NUM>, <NUM>) fixedly attached to the interface frame (<NUM>),
wherein:
the patient contact membrane (<NUM>, <NUM>), the static membrane (<NUM>), and the interface frame (<NUM>) define a cavity (<NUM>), the cavity (<NUM>) having a port (<NUM>, <NUM>) to introduce or remove an ultrasound coupling and cooling fluid to or from the cavity (<NUM>).