Mixing device and method for making bone cement - Patents.com

Abstract

A mixing device and method for making bone cement are disclosed. The piston of the mixing device is positioned in a first region of the chamber so that a mixing paddle rotates to mix the bone cement components at a first pressure to create a bone cement mixture. The piston passes through an inlet opening to be positioned in a second region of the chamber and compresses the bone cement mixture to a second pressure greater than the first pressure to create the bone cement. The bone cement can be transferred to a delivery device. The mixing device includes a function that automatically initiates a compression phase and a transfer phase after completion of the mixing phase, and may further include a function that automatically terminates the operating cycle. A three-step intuitive workflow utilizing the mixing device is also disclosed to improve efficiency in the operating room.

Description

[Technical Field]

[0001] [Priority claim] This application claims priority to and the full benefit of U.S. Provisional Patent Application No. 62 / 861,698, filed June 14, 2019, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] A common cause of low back pain is vertebral compression fractures, which result in the loss of height or collapse of a weakened or damaged vertebral body. Vertebral body weakening can result from acute injury or, more commonly, from degenerative changes such as osteoporosis. One treatment involves vertebral augmentation, in which vertebral body height is elevated or restored and stabilized at this elevated or restored height with a hardening bone cement. Bone cement typically contains bone cement components (e.g., powdered polymer and liquid monomer), which are packaged separately and mixed immediately before or during the vertebral augmentation procedure. Efficient, uniform, safe, and reproducible mixing of bone cement components is a particular area of ​​interest in development to ensure that the bone cement possesses the expected mechanical properties and attributes. Known devices requiring manual mixing (e.g., "open bowl" or vacuum techniques) are inefficient due to the need for operating room staff to vigorously agitate the bone cement components. Different staff may mix the bone cement components at varying intensities and / or for varying durations, which may result in a bone cement that is not particularly uniform or reproducible. Furthermore, some manual mixing devices may undesirably expose staff to the bone cement components. While known powered mixing devices overcome some of the aforementioned problems, they require staff to engage in a highly complex workflow, especially if the staff is unfamiliar with the device. Therefore, there is a need in the art for improved mixing devices and methods for making bone cement that overcome one or more of the aforementioned drawbacks. Summary of the Invention

[0003] A first aspect of the present disclosure is directed to a mixing device for creating a bone cement from bone cement components. The chamber defines an inlet opening and has first and second ends and a longitudinal axis extending between the first and second ends. A first region of the chamber is defined longitudinally between the first end of the chamber and an end of the inlet opening closest to the second end of the chamber. A second region of the chamber is defined longitudinally between the first and second ends of the chamber. The mixing device includes a piston disposed within the chamber. The piston includes a face. The mixing device includes a mixing paddle rotatable within the chamber. The face of the piston is configured to be located within the first region of the chamber such that the chamber is at subatmospheric pressure when the mixing paddle rotates to mix the bone cement components to create the bone cement mixture. The piston is movable along the longitudinal axis to position its face within the second region of the chamber to form a fluid-tight closure between the piston and the chamber such that further movement of the piston within the second region compresses the bone cement mixture within the chamber.

[0004] In some embodiments, a motor is operably coupled to the piston and the mixing paddle and configured to at least one of move the piston and rotate the mixing paddle. The housing further defines an outlet port adjacent the second end of the chamber. A first switch may be coupled to the housing and connected to the motor. The first switch may be movable to an energized state in which the first switch activates the motor while the piston is in the first region. The first switch may be a momentary switch biased toward a de-energized state. A second switch may be coupled to the housing and connected to the motor. The second switch may be movable to a de-energized state in which the second switch does not activate the motor while the piston is in the second region. The second switch may be a non-momentary switch in an initially energized state. The first switch and the second switch may be wired in series with the motor.

[0005] In some embodiments, an actuator is coupled to the housing and movable to engage the switch and maintain the switch in an energized state against a bias while the piston moves from the first region to the second region. A transfer gear is coupled to the motor and can be rotatable during an operating cycle. A stop nut can be configured to translate along the transfer gear to engage the actuator while the piston is in the second region.

[0006] A second aspect of the present disclosure includes a method of making bone cement using a mixing device according to the first aspect of the present disclosure, and optionally any of the corresponding embodiments thereof.

[0007] A third aspect of the present disclosure is directed to a mixing device for creating a bone cement from bone cement components. The mixing device includes a housing and a chamber within the housing. The chamber has a first region and a second region separate from the first region. The mixing device includes a mixing paddle rotatable within the chamber to mix the bone cement components to create a bone cement mixture. A piston is movable within the chamber to compress the bone cement components. A motor is coupled to the piston and the mixing paddle. A first switch is connected to the motor. The first switch is momentary and is biased to a de-energized state that prevents activation of the motor. The first switch is configured to transition from the de-energized state to an energized state that activates the motor to initiate an operating cycle by at least one of moving the piston and rotating the mixing paddle. A second switch is wired in series with the first switch and the motor. The second switch is non-momentary and is initially placed in an energized state to allow activation of the motor. The second switch is configured to transition from an energized state to a de-energized state that disables the motor and ends the operating cycle. The piston is configured to move within the chamber from a first region to a second region to mix and compress the bone cement mixture within the chamber. The piston is in the first region during activation of the first switch and in the second region during activation of the second switch.

[0008] In some implementations, the chamber is at subatmospheric pressure when the piston is in the first region, and the chamber is above atmospheric pressure when the piston is in the second region. An actuator is coupled to the housing and movable between a first position spaced from the first switch and a second position that engages and actuates the first switch.

[0009] A fourth aspect of the present disclosure includes a method of making bone cement using a mixing device according to the third aspect of the present disclosure, and optionally any of the corresponding embodiments thereof.

[0010] A fifth aspect of the present disclosure is directed to a mixing device for creating a bone cement from bone cement components. The mixing device includes a housing and a chamber within the housing. The chamber defines an inlet opening configured to receive the bone cement components. A mixing paddle is rotatable within the chamber to mix the bone cement components to create a bone cement mixture. A piston is movable within the chamber to compress the bone cement components. A motor is coupled to the piston and the mixing paddle. A first switch is attached to the housing connected to the motor, the first switch being initially in a de-energized state. A second switch is attached to the housing and spaced apart from the first switch. The second switch is in a conductive state. The first and second switches are wired in series with the motor. An actuator is coupled to the housing, spaced apart from the first switch, and movable between a first position in which the inlet opening is open to the ambient environment and a second position in which the actuator engages the first switch to transition the first switch from a de-energized state to a conductive state. A stop nut is movable into engagement with the second switch to transition the second switch from an energized state to a de-energized state.

[0011] In some embodiments, the actuator is a slider including a slider body and an arm extending from a lower surface of the slider body. The arm is configured to be laterally deflected to engage the first switch. The first switch and the second switch can be mounted directly to the housing at separate locations without being coupled to a printed circuit board.

[0012] A sixth aspect of the present disclosure includes a method of making bone cement using a mixing device according to the fifth aspect of the present disclosure, and optionally any of the corresponding embodiments thereof.

[0013] A seventh aspect of the present disclosure is directed to a mixing device for making bone cement. The mixing device includes a housing and a chamber within the housing. The chamber defines an inlet opening configured to receive bone cement components. The mixing device includes a mixing paddle rotatable within the chamber to mix the bone cement components to make a bone cement mixture. A piston is movable within the chamber to compress the bone cement components. A motor is coupled to the piston and the mixing paddle. A switch is connected to the motor. An actuator is coupled to the housing and movable between a first position and a second position. In the first position, the actuator is spaced from the switch, and the inlet opening is open to the ambient environment. In the second position, the actuator engages the switch to simultaneously (i) transition the switch from a de-energized state to an energized state in which the switch initiates an operating cycle by actuating the motor to at least one of moving the piston and rotating the mixing paddle, and (ii) close the inlet opening.

[0014] In some embodiments, the housing defines an aperture. The actuator may include a door positioned to be located between the entrance opening and the aperture when the actuator is in the second position. The entrance opening is positioned below the aperture such that bone cement components guided through the aperture further pass through the entrance opening and into the chamber under the influence of gravity. A funneling device may include a flared portion and a stem dimensioned to be received within the aperture of the housing. A flexible tether may couple the funnel device to the housing. The funneling device may include a detent on the stem. The detent is configured to releasably engage a complementary locking feature on the housing.

[0015] In some embodiments, the actuator of the ninth aspect is included in the mixing device of any one of the first, third, fifth, and seventh aspects, and may optionally be included in any of their corresponding embodiments.

[0016] An eighth aspect of the present disclosure includes a method of making bone cement using a mixing device according to the seventh aspect of the present disclosure, and optionally any of the corresponding embodiments thereof.

[0017] A ninth aspect is directed to a mixing device for making bone cement. The mixing device includes a housing having an upper shell and a lower shell coupled to the upper shell. A chamber is within the housing. The chamber defines an inlet opening configured to receive bone cement components. A mixing paddle is rotatable within the chamber to mix the bone cement components to make a bone cement mixture. A piston is within the chamber to compress the bone cement components. A motor is coupled to the piston and the mixing paddle. The upper shell includes a funnel with a sloped surface defining a hole in communication with the inlet opening.

[0018] In some embodiments, the upper shell has an upper surface with a sloped surface extending downwardly from the upper surface. The funnel is frusto-conical in shape.

[0019] In some embodiments, the integrated funnel of the ninth aspect is included in the mixing device of any one of the first, third, fifth, and seventh aspects, and may optionally be included in the mixing device of any one of these corresponding embodiments.

[0020] A tenth aspect of the present disclosure includes a method of making bone cement using a mixing device according to the ninth aspect of the present disclosure, and optionally any of the corresponding embodiments thereof.

[0021] An eleventh aspect is directed to a mixing device for making bone cement. The mixing device includes a housing and a chamber within the housing defining an inlet opening configured to receive bone cement components. A mixing paddle is rotatable within the chamber to mix the bone cement components to make a bone cement mixture. A piston is movable within the chamber to compress the bone cement components. A motor is coupled to the piston and the mixing paddle. A display device is coupled to the housing and configured to display information indicative of operation of the mixing device.

[0022] In some embodiments, the display device is a liquid crystal display (LCD), a series of light sources, a digital timer, or an analog timer. The information can be one of: a time remaining for operation of the mixing device, an elapsed time for working with the bone cement, and an estimated time remaining for working with the bone cement.

[0023] In some embodiments, the display device of the eleventh aspect may be included in the mixed device of any one of the first, third, fifth, seventh, and ninth aspects, and optionally in any one of their corresponding embodiments.

[0024] A twelfth aspect of the present disclosure comprises a method of making bone cement using a mixing device according to the ninth aspect of the present disclosure, and optionally any of the corresponding embodiments thereof.

[0025] A thirteenth aspect of the present disclosure is directed to a mixing device for making bone cement. The mixing device includes a housing and a chamber within the housing. The chamber has a first region and a second region separate from the first region. The mixing device includes a mixing paddle rotatable within the chamber to mix bone cement components to make a bone cement mixture. A piston is movable within the chamber to compress the bone cement components. A motor is coupled to the piston and the mixing paddle. A switch is connected to the motor. The switch is configured to transition between an energized state, in which the switch activates the motor to at least one of move the piston and rotate the mixing paddle, thereby initiating an operating cycle, and a de-energized state, in which the switch deactivates the motor, thereby terminating the operating cycle. The switch is biased toward the de-energized state. An actuator is coupled to the housing and is movable between a first position spaced from the switch and a second position, in which the actuator engages the switch to transition the switch from the de-energized state to the energized state and maintains the switch in the energized state against the bias. The piston is configured to move within the chamber from the first region to the second region such that when the piston is within the second region, the actuator is mechanically decoupled from the switch to bias the switch back from an energized state to a de-energized state.

[0026] In some embodiments, the switch is a momentary switch. A transfer gear is coupled to the motor and rotatable during an operating cycle. A stop nut is rotationally constrained coupled to the transfer gear such that the stop nut translates along the transfer gear to engage the actuator and mechanically disengage the actuator from the switch. The stop nut can include a nut portion having an inner diameter that threadably engages an outer diameter of the transfer gear, and a flange portion extending from the nut portion, the flange portion configured to engage the actuator to mechanically disengage the actuator from the switch.

[0027] In some implementations, the actuator is a slider comprising a slider body, an arm extending from a lower surface of the slider body, and a stop feature coupled to the arm and configured to engage the switch. The slider can further include a ramped surface coupled to the arm and positioned for engagement by the stop nut as the stop nut translates due to rotation of the transfer gear, wherein engagement of the stop nut with the ramped surface imparts bending to the arm and disengages the stop feature from the switch.

[0028] A fourteenth aspect of the present disclosure comprises a method of making bone cement using a mixing device according to the third aspect of the present disclosure, and optionally any of the corresponding embodiments thereof.

[0029] A fifteenth aspect of the present disclosure is directed to a kit for performing a vertebral augmentation procedure using bone cement. The kit includes a mixing device for mixing bone cement components to form a bone cement mixture and compressing the bone cement mixture. The mixing device includes a chamber, a piston movable within the chamber, and a mixing paddle movable within the chamber. The chamber defines an inlet opening and an outlet port communicating with the inlet opening. The kit includes a delivery device with a chamber defining an inlet port for receiving bone cement from the mixing device. The kit further includes packaging dimensioned to contain the mixing device and the delivery device. The inlet port of the delivery device communicates with the outlet port of the mixing device such that the mixing device and the delivery device are removably coupled to each other within the packaging. The mixing device and the delivery device are configured to be removed from the packaging as a single unit.

[0030] In some embodiments, when the mixing device and delivery device are removably coupled to one another, the longitudinal axis of the chamber of the mixing device and the longitudinal axis of the chamber of the delivery device are parallel so that the mixing device and delivery device are arranged in a side-by-side configuration within the package. The outlet port of the mixing device and the inlet port of the delivery device may be arranged perpendicular to their respective longitudinal axes to facilitate the side-by-side configuration.

[0031] In some embodiments, the kit includes a funnel device and a flexible connection connecting the funnel device and the mixing device. The funnel device is configured to be removed from the packaging as a single unit. Alternatively, the funnel device can be integrated into the housing. The kit can further include a liquid monomer and a powdered polymer disposed within a sterile packaging. The packaging can be a blister pack.

[0032] It will be readily appreciated that the advantages of the present disclosure will be better understood by reference to the following detailed description taken in conjunction with the accompanying drawings, in which it is understood that the drawings are purely illustrative and are not necessarily drawn to scale. [Brief explanation of the drawings]

[0033] [Figure 1] FIG. 1 is a rear perspective view of a mixing and delivery system including a mixing device and a delivery device. [Figure 2] FIG. 1 is a front perspective view of a mixing device. [Figure 3] FIG. 1 is a front perspective view of the mixing device with the upper shell of the housing removed. [Figure 4] FIG. 2 is a cross-sectional elevation view of a mixing device showing a piston positioned within a first region of a chamber of the mixing device. [Figure 5] FIG. 10 is a cross-sectional elevation view of the mixing device showing the piston positioned within the second region of the chamber of the mixing device. [Figure 6] FIG. 1 is a perspective view of a subassembly of the mixing device, including a switch, a piston, and a mixing paddle. [Figure 7] FIG. 10 is a perspective view of a gear train of the mixing device coupled to the piston and mixing paddle. [Figure 8] FIG. 1 is an elevational view of the gear train, piston, and mixing paddle. [Figure 9] FIG. 8 is an elevational view of the gear train and mixing paddle of FIG. 7 with the transfer gear and translation shaft removed to show the paddle drive gear that couples the mixing paddle to the gear train. [Figure 10] FIG. 1 is an exploded view of a subassembly of a mixing device configured to effect longitudinal movement of a piston (and mixing paddle) within a chamber, the subassembly including a transfer gear, a translation shaft, a rear chamber housing, and a push cap. [Figure 11] 1 is an elevational view of a component of a mixing device configured to provide automatic termination of an operating cycle, the component including a stop nut disposed in a first position on a transfer gear. [Figure 12] FIG. 12 is an elevational view of the components of FIG. 11 with the stop nut positioned in a second position on the transfer gear and engaging the actuator. [Figure 13] FIG. 1 is a perspective view of a slider forming an actuator. [Figure 14] FIG. [Figure 15] FIG. 10 is a top perspective view of a portion of a mixing device with the mounting portion of the actuator deflected laterally to engage the mounting portion of the switch. [Figure 16] FIG. 10 is a top perspective view of a portion of the mixing device in which a mounting portion of the stop nut is configured to engage a second switch to effect automatic termination of the operating cycle. [Figure 17] FIG. 10 is a rear perspective view of the mixing device with the release assembly in the unlocked position. [Figure 18] FIG. 12 is a perspective view of a front chamber housing including a transfer conduit. [Figure 19A] 19A is a detailed view of the transfer conduit and release assembly within dashed line 19A-19A of FIG. 17. [Figure 19B]FIG. 10 is a detailed view of another embodiment of a transfer conduit and release assembly. [Figure 20] FIG. 19B is a perspective view of the release assembly of FIG. 19A. [Figure 21] 2 is a pictorial representation of one step of a method of using a kit including the mixed delivery system of FIG. 1. [Figure 22] 1 is a visual representation of another step of the method. [Figure 23] 1 is a visual representation of another step of the method. [Figure 24] 1 is a visual representation of another step of the method. [Figure 25] 1 is a visual representation of another step of the method. [Figure 26] FIG. 1 is a front perspective view of a mixing and delivery system including a mixing device and a delivery device. DETAILED DESCRIPTION OF THE INVENTION

[0034] Referring now to the figures, where like numerals indicate corresponding parts throughout the several views, a mixing delivery system 100 is shown in FIG. 1 . The system 100 includes a mixing device 102 for mixing multiple components to form a mixture and a delivery device 104 for delivering the mixture to a target site. The system 100 is useful for any procedure requiring delivery of a mixture to a target site. In one example, the mixing device 102 mixes bone cement components to form a bone cement mixture, which is transferred to the delivery device 104. In particular, upon activation, the mixing device 102 automatically performs an operating cycle including a mixing phase and a compaction phase and automatically transfers the bone cement to the delivery device 104 in an intuitive workflow described below. The intuitive workflow promotes operating room efficiency and density of the bone cement mixture while reducing user exposure to the bone cement components. Once transferred to the delivery device 104, the delivery device 104 is manipulated by the user to deliver the bone cement into a vertebral body, for example, during a vertebroplasty or kyphoplasty procedure. One example of a delivery device 104 suitable for the present system is disclosed in commonly owned International Publication No. WO 2019 / 200091, published October 17, 2019, the entire contents of which are incorporated herein by reference. Another example of a delivery device 104 suitable for the present system is disclosed in commonly owned U.S. Patent No. 6,547,432, issued April 15, 2003, the entire contents of which are incorporated herein by reference.

[0035] 1 shows a delivery device 104 removably coupled to a mixing device 102. The delivery device 104 includes an inlet port 106 configured to be removably placed in sealed fluid communication with an outlet port 108 of the mixing device 102. A release assembly 110, described in more detail, facilitates communication between the mixing device 102 and the delivery device 104, thereby establishing communication between the inlet port 106 and the outlet port 108. The communication between the inlet port 106 and the outlet port 108 further establishes fluid communication between a chamber 112 of the mixing device 102 (see FIGS. 4 and 5 ) and a chamber (not explicitly shown) within the delivery device 104 for transporting the bone cement mixture.

[0036] The mixing device 102 includes a housing 116. Figures 1, 2, and 3 show embodiments of the housing 116, with like numbers referring to like components but differences in function and design. The housing 116 of Figure 1 includes a cradle 114 and / or a hook 117 coupled to the housing 116, for example, to support the delivery device 104. The cradle 114 may be sized and shaped to facilitate separation of the housing 118 of the delivery device 104 from the mixing device 102, and the hook 117 may be sized and shaped to facilitate transporting and separating the extension tube 105 of the delivery device 104. Figure 1 shows the cradle 114 as an arc-shaped protrusion roughly sized to fit a portion of the housing 118 of the delivery device 104. In such a coupled configuration, the cradle 114 cooperates with the release assembly 110 to allow the system 100 to be moved as a unit, for example, with one hand. In one configuration, the exit port 108 is located on the side of the mixing device 102, allowing the delivery device 104 and mixing device 102 to be packaged in a combined configuration prior to deployment in the operating room, with advantages that will be described in more detail below, although other placements of the exit port 108 are also contemplated.

[0037] The embodiment of FIG. 2 shows the cradle 114 further including a control surface 115 configured to receive input from a user to enable removal of the housing 118 of the delivery device 104 from the cradle 114. In particular, the cradle 114 can be formed from a material that allows the cradle 114 to flex upon user input. In the absence of user input, the cradle 114 can provide a holding force to the housing 118 of the delivery device 104. In another embodiment, the holding force provided by the transfer conduits 306, 306′ of the mixing device 102 and the release assembly 110 of the delivery device 104 (see FIGS. 17-20 ) is sufficient to maintain the relative positions of the mixing device 102 and the delivery device 104. The cradle 114 supports the delivery device 104 but does not otherwise provide a holding force.

[0038] Referring now to FIG. 2 , the mixing device 102 includes a housing 116, which can be formed from a suitable material and manufacturing process. The housing 116 can include an upper shell 120 and a lower shell 122 coupled to the upper shell 120. The cavities defined by each of the upper shell 120 and the lower shell 122 are sized to accommodate most of the components of the mixing device 102. The upper shell 120 and the lower shell 122 can be removably coupled to each other or permanently coupled to each other. Because the mixing device 102 is potentially a single-use, disposable component, access to the interior 124 of the housing 116 may be rare. However, even in such cases, the housing 116 can include a separation feature 126 configured to receive an input from a user to separate the upper shell 120 from the lower shell 122, thereby exposing the components contained within the interior 124 of the housing 116. 1 shows the separation feature 126 as a tab 128 adjacent to a gripping feature 130 at the interface between the upper and lower shells 120, 122. An input force applied to the tab 128 while maintaining the position of the gripping feature 130 overcomes the holding force provided by a detent at the interface between the upper and lower shells 120, 122 (FIG. 3 clearly shows the female portion 132 of the detent). A separate gripping feature 134 extending around at least a portion of the upper shell 120 can optionally allow the housing 116 and system 100 to be moved as a unit, for example, with one hand, as described above.

[0039] Continuing to refer to FIG. 2 , the housing 116 includes or defines a bore 135. The bore 135 extends through the top wall of the upper shell 120 of the housing 116. The bore 135 is generally an orifice through which bone cement components are introduced into the chamber 112 prior to the initiation of an operating cycle that includes mixing, compressing, and transporting phases. FIGS. 4 and 5 illustrate the chamber 112 and, more particularly, a front chamber housing 164 that includes or defines an inlet opening 136 that communicates with the bore 135 and the chamber 112. The inlet opening 136 can be positioned directly below the bore 135 such that bone cement components introduced through the bore 135 are further passed through the inlet opening 136 and into the chamber 112 under the influence of gravity. The chamber 112 is disposed within the housing 116.

[0040] A funnel device 138 can be provided to facilitate efficient introduction of bone cement components through the bore 135. The bone cement components typically include a liquid monomer and a powdered polymer. The funnel device 138 includes an enlarged opening opposite a narrow opening defined by a stem 140 sized to be received in the bore 135 of the housing 116. Additionally, the funnel device 138 can include a flexible connection 142 that couples the funnel device 138 to the housing 116. The flexible connection 142 can be retained by threading it through a slot in the upper shell 120 of the housing 116, although other suitable connection means are contemplated. Among other advantages, the flexible connection 142 allows the funnel device 138 to be packaged while still coupled to the housing 116 and further allows the system 100 including the funnel device 138 to be moved as a unit, e.g., with one hand. Known systems that include a funnel require the funnel to be handled separately, necessitating additional transport across the sterile barrier of an operating room. The flexible connection 142 is coupled to the housing 116 with the funnel device 138 upside down in an initial configuration, as shown in FIGS. 1 and 2 . During an intuitive workflow step, the user manipulates the funnel device 138 to place the stem 140 into the bore 135. This can be considered the first step of the workflow, as indicated by the indicia 144 on the funnel device 138, which is the number “1.” In some embodiments, the funnel device 138 can include a detent (not shown) disposed on the stem 140. The detent is configured to releasably engage a complementary opening 143 defined in the housing 116 near the bore 135. When the detent is engaged, the user is provided with visual and / or tactile feedback that the funnel device 138 is properly positioned to receive the bone cement component. The user then introduces the bone cement component into the funnel device 138, which is guided to the chamber 112.

[0041] A user initiates a motion cycle by actuating an actuator 148, for example, a slider 150, further described, that is movably coupled to the housing 116. The actuator 148 may include indicia 152, in this case the number "2," that corresponds to the second step of the intuitive workflow.

[0042] The operating cycle includes a mixing stage in which a mixing paddle 154 disposed within the chamber 112 mixes the bone cement components, and a compression stage in which a piston 156 disposed within the chamber 112 compresses the bone cement and transfers it to the delivery device 104 via the outlet port 108. Referring now to Figures 4 and 5, cross-sectional elevation views of the mixing device 102 are shown, with Figure 4 illustrating the mixing device 102 during the mixing stage and Figure 5 illustrating the mixing device 102 during the compression and transfer stages.

[0043] The mixing stage generally occurs when the piston 156 is in a first region 158 of the chamber 112 such that the bone cement components enclosed within the chamber 112 are at a first pressure, and the transfer stage generally occurs when the piston 156 is in a second region 160 of the chamber 112 such that the bone cement components are compressed to a second pressure greater than the first pressure. In one example, the first pressure is subatmospheric (e.g., at or near 1 atmosphere, substantially equal to ambient pressure, etc.), and the second pressure is greater than atmospheric (e.g., 4-7 atmospheres). The chamber 112 can be defined by or within a front chamber housing 164 (see FIG. 18) coupled to a rear chamber housing 166 (see FIG. 10). Referring simultaneously to FIG. 3, the front chamber housing 164 can be cylindrical in shape and can extend beyond the housing 116. The front chamber housing 164 can include an inner surface 168 that at least partially defines the chamber 112. The rear chamber housing 166 may be a complementary cap-like feature to the front chamber housing 164 and define a front surface 170 that at least partially defines the chamber 112 opposite the inner surface 168 (see FIG. 10 ). Conventionally, the front surface 170 of the rear chamber housing 166 may define the first end 162 of the chamber 112, and the inner surface 168 of the front chamber housing 164 may define the second end 163 of the chamber 112, as also shown in FIGS. 4 and 5 .

[0044] The first region 158 and the second region 160 are represented schematically in FIGS. 4 and 5. The first region 158 of the chamber 112 may define a height between a first end 162 of the chamber 112 and an end 172 of the inlet opening 136 closest to the inner surface 168. More specifically, the first region 158 may be defined between the first end 162 of the chamber 112 and a plane that intersects the end 172 of the inlet opening 136 and is perpendicular to the longitudinal axis LA of the chamber 112. In other words, when the face 174 of the piston 156 moving along the longitudinal axis LA has not yet reached the end 172 of the inlet opening 136 that defines the boundary between the first region 158 and the second region 160, the face 174 is in the first region 158, at least a portion of the inlet opening 136 is generally open to the surroundings, and the chamber 112 is at least substantially atmospheric pressure. The second region 160 can be defined between the end 172 and the inner surface 168 of the inlet opening 136. In other words, when the face 174 of the piston 156 moving along the longitudinal axis LA is in the second region 160 and the face 174 passes the inlet opening 136, a fluid-tight closure can be formed between the piston 156 and the housing 116, sealing the chamber 112 from the environment. Thus, in operation, when the face 174 of the piston 156 is in the first region 158 of the chamber 112 extending longitudinally between the first housing end 162 and the open end 172, the bone cement components are mixed by the mixing paddle 154 at a first pressure, or atmospheric pressure, to create a bone cement mixture. Piston 156 then moves along longitudinal axis LA to position in second region 160 extending longitudinally between open end 172 and second housing end 163 to compress the bone cement mixture in chamber 112 to a second pressure greater than the first pressure or atmospheric pressure. The bone cement mixture can also be transferred to delivery device 104 via outlet port 108 in communication with chamber 112. Among other readily apparent advantages, piston 156, which passes through inlet opening 136 and seals chamber 112 during compression and transfer of the bone cement to delivery device 104, reduces or eliminates the need for many high-pressure components required in existing systems.For example, existing systems may require an attachable lid, and the lid and the method of connecting the lid to the device must be designed to withstand the high pressures associated with the compression phase. Lids and their interfaces are often prone to catastrophic failure. They may not be intuitive to the user and therefore prone to mis-installation and subsequent failure. The lid must be transported to the sterilization chamber separately from the mixer, increasing the risk of contaminating sterile surfaces. The lid may also be dropped or roll off the table, rendering the mixing unit unusable. The piston 156, which passes through the inlet opening 136 and seals the chamber 112, eliminates the need for an attachable lid. Consequently, the self-sealing nature of the chamber 112 of the mixing device 102 reduces or eliminates the possibility of inadvertent user exposure to bone cement mixture under high pressure.

[0045] The mixing device 102 may include a sealing element (not explicitly shown) coupled to the piston 156 to form a fluid-tight closure between the piston 156 and the housing 116. Near a face 174 of the piston 156, the piston 156 may include a recess 175. The recess 175 may extend annularly around the piston 156, with a sealing element, such as an O-ring gasket, located at least partially within the recess 175. The sealing element interacts with an inner surface of the housing 116 to form a fluid-tight closure between the piston 156 and the housing 116.

[0046] The electromechanical operation of the mixing device 102 to impart rotation of the mixing paddle 154 during the mixing phase will now be described with reference to FIGS. 4-9. The mixing device 102 can be powered by a battery pack 176 including multiple batteries, as shown in FIGS. 4 and 5. In one example, the battery pack 176 includes eight conventional AA batteries, although alternatives such as lithium-ion and / or other disposable or rechargeable batteries are contemplated. Although less convenient for the operating room, the mixing device 102 can also be adapted to be powered in a corded configuration. The mixing device 102 further includes a motor 178 that connects with the battery pack 176. Furthermore, the mixing device 102 further includes a switch 180 that connects with the motor 178 and is configured to be driven between an energized state and an unenergized state. In one example, the switch 180 is a momentary microswitch that is internally biased to a de-energized state. This advantageously allows the switch 180 to be returned to its original position to discontinue operation of the mixing device 102, if desired. In another example, the switch 180 is a non-momentary switch, such as a toggle switch. Actuating the switch 180 in a manner described in more detail below activates the motor 178, providing a rotational output on the output shaft 182 of the motor 178. The motor 178 is optional, and it is contemplated that the mixing device 102 may be a manual mixing device. In such an example, the piston may resemble an axial plunger and mixing paddle configured to receive input from a user. The plunger may be in the first region 158 when the bone cement components are mixed with the mixing paddle 154 at atmospheric pressure, and the plunger may move to the second region 160 in response to input from the user to compress the bone cement mixture in the chamber 112 to a pressure greater than atmospheric pressure. Alternatively, manual mixing may be performed using an axial mixing blade configured to receive axial and rotational input from the user, as disclosed in the aforementioned U.S. Patent No. 6,547,432. Another non-motorized configuration may include a manually operated crank that operates a gear train that both rotates the mixing paddle 154 and advances the piston 156 .

[0047] Output shaft 182 is operably coupled to gear train 184, best shown in FIGS. 7-9. The illustrated gear train 184 is a stacked spur gear configuration, although other suitable configurations are contemplated (e.g., planetary gears, helical spur gears, helical planetary gears, etc.). Gear train 184 includes a pinion gear 186 coupled to output shaft 182 of motor 178. A first spur gear 188 is operably coupled to pinion gear 186. First spur gear 188 includes a first spur gear 190 having a larger outer diameter, with first spur gear 190 coupled to pinion gear 186, and a second spur gear 192 having a smaller outer diameter. A second spur gear 194 is operably coupled to first spur gear 188. The second spur gear 194 includes a first spur gear 196 having a larger outer diameter, with the first spur gear 196 coupled to the second spur gear 192 of the first spur gear 188, and also includes a second spur gear 198 having a smaller outer diameter. A third spur gear 200 is operatively coupled to the second spur gear 194. The third spur gear 200 includes a first spur gear 202 having a larger outer diameter, with the second spur gear 202 coupled to the second spur gear 198 of the first spur gear 194, and also includes a second spur gear 204 having a smaller outer diameter. The third spur gear 200, and more specifically the first spur gear 202 of the third spur gear 200, is operatively coupled to the input spur gear 206 of the paddle drive gear 208. The third spur gear 200 is also operatively coupled to a fourth spur gear 210. The fourth spur gear 210 includes a first spur gear 212 having a larger outer diameter coupled to the second spur gear 204 of the third spur gear 200, and a second spur gear 214 having a smaller outer diameter coupled to a transfer gear 216 as described. Figures 6 and 7 together show the gear train 184 disposed within a front gear train housing 218 and a rear gear train housing 220 that are operatively coupled to one another. Additionally, the rear chamber housing 166 is operatively coupled to the front gear train housing 218.

[0048] In some implementations, vibration and noise can be reduced by using vibration damping and / or vibration isolation between the motor 178 and / or gear train 184 and complementary components of the gear train housing 218. Vibration damping can be achieved by fabricating one or more gears from a lower modulus (i.e., more compliant) material, such as an elastomeric polyester such as Hytrel® manufactured by DuPont de Nemours, Inc. (Wilmington, Del.). Vibration isolation can be achieved by placing a compliant material, such as an elastomer or foam, between a vibrating component and an adjacent component, for example, between the motor 178 and adjacent portions of the gear train housing 218 (see FIG. 6) or between the gear train housing and the mixer housing. Other suitable locations for vibration damping or isolation include the first spur gear 188 and the second spur gear 200, which rotate the fastest in the gear train 184 and therefore contribute the most noise. It is further contemplated that some compliance may be provided between pinion gear 186 and first spur gear 188 to further reduce noise and sensitivity to adjustments of the component stack.

[0049] With particular reference to FIG. 9 , the mixing paddle 154 can be coupled to an end of an output shaft 222 of a paddle drive gear 208, which is coupled to the input spur gear 206. The output shaft 222 includes a longitudinally extending rail configured to mate with a complementary feature in a stem 224 of the mixing paddle 154 to rotatably secure the mixing paddle 154 to the paddle drive gear 208. The mixing paddle 154 further includes a face portion 226 extending generally radially from the stem 224. The face portion 226 is disposed adjacent to and rotatable relative to the face 174 of the piston 156, as can be seen in FIGS. 6 and 7 . A mixing feature 228 is coupled to the face portion 226. The mixing feature 228 extends longitudinally forward of the face portion 226 and includes at least one leg 230 for agitating the mixed components during rotation of the mixing paddle 154. 7 and 9 show two of the legs 230 joined together by a head 232 to form a generally U-shaped mixing function 228. Each of the legs 230 and head 232 may be plate-like in configuration with the head 232 angled inward relative to the legs 230 to flex or buckle the mixing function 228 against the face portion 226 during the compression and transfer stages in a manner that will be described in more detail. Other configurations of the mixing paddle 154 configuration are also contemplated.

[0050] In operation, the switch 180 moves from a de-energized state to an energized state. The motor 178 draws power from the battery pack 176 or other power source and operates to provide torque to the gear train 184. This operation can be considered the start of an operating cycle, or more specifically, the mixing phase of the operating cycle. According to known speed-torque characteristics associated with gearing, torque is transmitted from the pinion gear 186 through each of the first, second, and third spur gears 188, 194, 200, and through the paddle drive gear 208 to the mixing paddle 154.

[0051] Rotating the mixing paddle 154 mixes the bone cement components in the chamber 112. Referring again to FIG. 4 , the mixing paddle 154 can be rotated while the piston 156 is positioned within the first region 158 of the chamber 112. Again, the face 174 of the piston 156 is located between the first end 162 of the chamber 112 and the boundary separating the first region 158 and the second region 160, such that the mixing paddle 154 mixes the bone cement components through the chamber 112 at at least substantially atmospheric pressure. It is understood that the door 234 of the slider 150 is positioned to cover the inlet opening 136 during an operating cycle that includes a mixing phase to prevent debris from escaping from the mixing device 102, but the door 234 cannot cause more than a minimal pressurization of the chamber 112 during movement of the piston 156. The door 234 can be disposed between the aperture 135 defined by the housing 116 and the inlet opening 136 defined by the chamber 112 when the actuator 148 is in the second position. At least in part because the bone cement components are mixed at atmospheric pressure in the chamber 112, a sealing element 236 disposed in the outlet port 108 of the mixing device 102 prevents spillage or premature transfer of the bone cement mixture from the mixing device 102 to the delivery device 104. As a result, a less complex and more cost-effective valve can be utilized to form the sealing element 236.

[0052] As can be further appreciated from FIG. 4 , the legs 230 of the mixing paddle 154 extend forward from the piston 156 such that the head 232 of the mixing paddle 154 is positioned proximate or adjacent to the inner surface 168 of the front chamber housing 164. This arrangement allows the mixing paddle 154 to access substantially the entire chamber 112 so that no portion of the bone cement components is insufficiently mixed or agitated. In other words, the legs 230 can effectively remove any bone cement components adhering to the sidewalls at least partially defining the chamber 112, and the head 232 can effectively remove any bone cement components adhering to the inner surface 168 at least partially defining the chamber 112. However, as previously mentioned and further described, the piston 156 moves from the first region 158 to the second region 160 for the compression and transfer phases. As a result, the mixing paddle 154 must accommodate this longitudinal movement of the piston 156 within the chamber 112. To that end, the mixing paddle 154 is configured to flex or buckle while the piston 156 compresses the bone cement mixture within the chamber 112. The piston 156 and mixing paddle 154 move along the longitudinal axis LA until the head 232 of the mixing paddle 154 abuts the inner surface 168 of the front chamber housing 164. Because the head 232 is angled inward relative to the legs 230, the continued force exerted by the piston 156 causes the legs 230 to deform at the interface 238 between the legs 230 and the face portion 226 (see FIGS. 7 and 8 ). This deformation can be thought of as buckling at the pivot point induced by the interface 238. The axial profile of the face portion 226 relative to the face 174 of the piston 156 corresponds to the legs 230 and head 232 such that, when nearly or fully flexed, the mixing feature 228 is substantially flat and abuts or is adjacent to the face 174 of the piston 156. Among other advantages, this arrangement allows the piston 156 to move longitudinally throughout substantially the entire chamber 112 to compress the bone cement mixture and transport it through the outlet port 108 located near the second end 163 of the chamber 112 (see FIG. 5 ).

[0053] The electromechanical operation of mixing device 102 to impart longitudinal movement of piston 156 (and mixing paddle 154) will now be described with reference to Figures 4, 5, 8, 9, and 10. As previously mentioned, fourth spur gear 210 includes second spur gear 214 coupled to transfer gear 216. Figures 7, 8, and 10 best illustrate transfer gear 216, which includes transfer spur gear 240 and a threaded shaft 242 extending from transfer spur gear 240. Transfer spur gear 240 is coupled to second spur gear 214 of fourth spur gear 210 such that rotation of gear train 184 including fourth spur gear 210 imparts rotation to transfer gear 216. As best shown in Figure 10, transfer gear 216, and more specifically threaded shaft 242, defines an inner bore 246 extending therethrough. At least one rail feature 248 is disposed within the bore 246 and oriented along the length of the bore 246. Figure 10 shows two rail features 248 disposed diametrically opposite one another. The bore 246 is further defined at the rear end thereof by a front face (not shown) of the transfer spur gear 240. A bore (not shown) having a smaller diameter than the bore 246 extends through the transfer spur gear 240 and is sized to allow the output shaft 222 of the paddle drive gear 208 to be disposed through the transfer gear 216, as shown in Figures 4 and 5, and more generally understood by viewing Figures 7 and 9 together.

[0054] With particular reference to FIGS. 8 and 10 , a translation shaft 244 is movably disposed within a bore 246 of the transfer gear 216. The translation shaft 244 includes an outer diameter that is smaller than the inner diameter of the bore 246 such that the translation shaft 244 is slidably movable within the bore 246. Additionally, the translation shaft 244 includes threads 250 disposed about its outer surface having the described functionality. The threads 250 can define at least one slot 252 extending longitudinally between opposing ends 245, 247 of the translation shaft 244. While FIG. 10 clearly illustrates one slot 252, it should be understood that there is another slot 252 radially opposite the slot 252 that is configured to engage with a rail feature 248 of the transfer gear 216. Engagement of the rail feature 248 and the slot 252 prevents relative rotation between the translation shaft 244 and the transfer gear 216 while allowing translation. The translation shaft 244 may also define a bore 254 extending between the opposing ends 245, 247, the bore 254 being sized to allow the output shaft 222 of the paddle drive gear 208 to be disposed therethrough, as shown in Figures 4 and 5 and more generally understood by viewing Figures 7 and 9 together. Thus, the paddle drive gear 208, the translation shaft 244, and the transfer gear 216 may be coaxially disposed.

[0055] A biasing element (not shown), e.g., a coil spring, is disposed within the bore 246 of the transfer gear 216. The biasing element includes an end disposed against the transfer spur gear 240 and another end disposed against the rear end 247 of the translation shaft 244. The biasing element biases a front end 245 of the translation shaft 244, opposite the rear end 247, toward and into contact with the rear chamber housing 166. With continued reference to FIG. 10 , the rear chamber housing 166 defines a bore 256 with internal threads 258. The bore 256 may be coaxially aligned with the paddle drive gear 208, the translation shaft 244, and / or the transfer gear 216. The bore 256 is sized to allow the output shaft 222 of the paddle drive gear 208 to be positioned through the rear chamber housing 166, and is further sized such that the internal threads 258 are configured for threaded engagement with the threads 250 of the translation shaft 244. It should be appreciated that the rear chamber housing 166 is a fixed component of the mixing device 102, such that the threaded engagement between the internal threads 258 and the threads 250 of the translation shaft 244 imparts translational movement of the translation shaft 244 relative to the rear chamber housing 166 (and relative to the transfer gear 216).

[0056] The rear chamber housing 166 can define a bore 260 that communicates with the bore 256 and is disposed on a side of the rear chamber housing 166 opposite the translation axis 244. The bore 260 is sized to initially receive at least a portion of a push cap 262. FIG. 10 illustrates the push cap 262 as a ring-like structure that includes an outer portion 264 that is sized to be received in the bore 260 and is disposed adjacent a front surface 266 of the bore 260 adjacent the internal threads 258. The push cap 262 includes a bore 268 that is sized to allow the output shaft 222 of the paddle drive gear 208 to be disposed therethrough. The outer portion 264 of the push cap 262 opposite the side that engages the front surface 266 is configured to engage an annular slot (not shown) on the rear side of the piston 156.

[0057] In operation, the switch 180 moves from a de-energized state to an energized state. The motor 178 draws power from the battery pack 176 and operates to provide torque to the gear train 184 to actuate the mixing paddle 154. As previously mentioned, this action can be considered the start of the mixing phase of the operating cycle, with torque being transferred in the illustrated gear train 184 from the pinion gear 186 through the first, second, and third spur gears 188, 194, and 200, respectively, and through the paddle drive gear 208 to the mixing paddle 154. The mixing paddle 154 immediately begins to rotate. Simultaneously, torque is transferred from the fourth spur gear 210 through the first, second, and third spur gears 188, 194, and 200, respectively, to the transfer gear 216. The transfer gear 216 immediately begins to rotate, albeit at a speed different from that of the mixing paddle 154. The translation shaft 244 rotates with the transfer gear 216 because rotation is constrained by a rail feature 248 of the transfer gear 216 that engages a slot 252 in the translation shaft 244. Meanwhile, the biasing element biases the front end 245 into contact with the rear chamber housing 166 such that the threads 250 of the translation shaft 244 engage with internal threads 258 of the rear chamber housing 166. The threaded engagement of the threads 250, 258 results in translational movement of the translation shaft 244 relative to the transfer gear 216. In other words, the translation shaft 244 can be rotating and translating simultaneously.

[0058] As previously mentioned, at least a portion of the push cap 262 is initially positioned within the bore 260 adjacent the front surface 266. Additionally, FIG. 10 illustrates the bore 256 of the rear chamber housing 166, having a depth or length defined between the front surface 266 and an opposite rear surface (not shown). The depth of the bore 256 is the distance the translation shaft 244 must travel before the front end 245 of the translation shaft 244 engages the inner portion 270 of the push cap 262, thereby moving the push cap 262 and, in turn, the piston 156. This distance, in conjunction with the pitch of the threads 250, 258, is specifically tailored to provide a time lag between the mixing phase of the operating cycle and the compression and transport phases of the operating cycle. In other words, during the time lag while the translation shaft 244 travels through the depth of the bore 256, the mixing paddle 154 rotates, mixing the bone cement components in the manner previously described. In one example, the time lag is 30 seconds, although other time frames are contemplated. Once the translation shaft 244 urges the push cap 262 against the piston 156, the continuing torque provided via the gear train 184 causes the piston 156 to move along the longitudinal axis. This movement is considered a transition phase of the operating cycle because, although the piston 156 is moving, the face 174 of the piston 156 must still enter the second region 160 of the chamber 112 (e.g., the face 174 of the piston 156 may only partially pass through the inlet opening 136). Thus, the chamber 112 may remain at generally atmospheric pressure during the transition phase. It should be further understood that, for at least a brief period of time, the piston 156 may be moving along the longitudinal axis LA while the mixing paddle 154 is fully extended and rotating (because the head 232 of the mixing paddle 154 must still contact the interior surface 168 and begin to bend or buckle, as previously described).

[0059] 4 , FIG. 5 illustrates the translation shaft 244 moved along the longitudinal axis LA and spaced from the rear chamber housing 166, with the corresponding movement of the push cap 262 and piston 156 (with the mixing paddle 154 removed for clarity). As previously described, the face 174 of the piston 156 passes through the inlet opening 136, more specifically the end 172 of the inlet opening 136, such that a fluid-tight closure is formed between the piston 156 and the housing 116, sealing the chamber 112 from the environment. FIG. 5 illustrates the face 174 of the piston 156 within the second region 160. The piston 156 compresses the bone cement mixture in the chamber 112 to a pressure greater than atmospheric pressure, and the bone cement can also be transferred to the delivery device 104 via the outlet port 108, which is in communication with the chamber 112. From the above, it will be readily appreciated that a single actuation of switch 180 causes mixing device 102 to advantageously perform mixing and time-lag compression and transport steps in a manner that mixes bone cement components at atmospheric pressure and compresses and transports the bone cement mixture in a self-sealing, closed system.

[0060] Additionally, mixing device 102 is further configured to automatically terminate an operating cycle after a predetermined period based on the completion of the mixing, compression, and transfer stages. Referring again to FIGS. 4 and 5, and further to FIGS. 11-14, a user initiates an operating cycle by actuating actuator 148, e.g., slider 150, movably coupled to housing 116. Slider 150 and switch 180 are complementary arranged such that moving slider 150 from a first position (see FIG. 1) to a second position (see FIGS. 4, 5, 11, 12, and 17) causes switch 180 to move from a de-energized state to an energized state, thereby initiating an operating cycle. In one embodiment, switch 180 can be biased to a de-energized state, and when slider 150 is in the second position, switch 180 remains energized against the bias. When the piston 156 is within the second region 160, the actuator 148 is mechanically disengaged from the switch 180, allowing the biased switch 180 to return from an energized state to a de-energized state. In one example, in a manner described in more detail, a stop nut 272 is configured to disengage the slider 150 from the switch 180, thereby allowing the switch 180 to be biased back to a de-energized state, thereby terminating the operating cycle. In another example, a structure such as a flange or arm coupled to the piston 156 may disengage the slider 150 from the switch 180, thereby allowing the switch 180 to be biased back to a de-energized state. In another embodiment described in more detail, a stop nut 272′ is configured to engage the second switch 181′ to return the mixing device 102 to a de-energized state, thereby terminating the operating cycle. In yet another example, an action such as cutting a cable occurs when piston 156 is properly within second region 160, which action will bias switch 180 back to a de-energized state. Alternatively, as previously mentioned, it is contemplated that switch 180 is a non-momentary switch and that when piston 156 is within second region 160, switch 180 will automatically and mechanically move to a de-energized state, ending the operating cycle and preventing motor 178 from operating.

[0061] FIG. 13 is a perspective view of slider 150 forming actuator 148. Slider 150 includes a slider body 274 including a control surface 276 opposite a lower surface 278. Control surface 276 can be considered a surface configured to receive user input, for example, to move slider 150 from a first position to a second position. Slider 150 also includes a first arm 280 and a second arm 282 separate from first arm 280. First arm 280 and second arm 282 extend from or are coupled to lower surface 278. In particular, FIGS. 11-13 show slider body 274 of slider 150 including a protrusion 284 extending downwardly from lower surface 278, with each of first arm 280 and second arm 282 extending generally laterally from protrusion 284. The protrusion 284 serves to space the first arm 280 and the second arm 282 from the underside 278 of the slider body 274 so that the first arm 280 and the second arm 282 are positioned inside 124 of the housing 116, and further so that the slider body 274 including the control surface 276 is outside of the housing 116 for user operation.

[0062] A door 234 is coupled to the first arm 280. As previously described, the door 234 is sized and contoured to cover the entrance opening 136 of the chamber 112, more specifically, to cover it when the slider 150 is in the second position. The door 234 covering the entrance opening 136 forms a closure that, although not pressurized and cannot be considered fluid-tight, prevents the escape of bone cement components from the chamber 112 during the mixing phase of the operating cycle. An engagement member 286 is coupled to the second arm 282 and includes a stop feature 288 and a ramped surface 290. FIG. 13 illustrates the stop feature 288 as a flange extending laterally from the engagement member 286. When the slider 150 moves from the first position to the second position, the stop feature 288 of the engagement member 286 engages the switch 180, moving the switch 180 from a de-energized state to a de-energized state. Stop feature 288 continues to maintain switch 180 in an energized state against the internal bias of switch 180 until it is disengaged from switch 180 by stop nut 272 in a manner to be further described. Figures 11, 12, and 15 show slider 150 in a second position such that switch 180 is engaged and energized (some support structure in Figures 11, 12, 15, and 16 has been removed to clearly show the relative positions between the illustrated components).

[0063] FIG. 14 illustrates a stop nut 272 including a nut portion 292 and a flange portion 294. The nut portion 292 is ring-shaped in configuration and includes a bore 296 and internal threads 298 sized and shaped for threaded engagement with the threaded shaft 242 of the transfer gear 216 (see FIGS. 4, 5, 7, and 10-12). The flange portion 294 includes at least one flange 300 extending generally radially outward from the outer surface of the nut portion 292. While FIG. 14 illustrates two flanges 300 separated by a slot, only one flange is also contemplated. Each of the flanges 300 includes a side surface 302 configured to engage a surface defining a slot 304 in the upper shell 120 of the housing 116. Referring to FIG. 6, one of the flanges 300 is shown positioned within the slot 304. As a result, rotation of the stop nut 272 relative to the housing 116 is prevented, and therefore, rotation of the transfer gear 216 causes the stop nut 272 to translate along the threaded shaft 242 of the transfer gear 216 .

[0064] In operation, a user provides input to the actuator 148, for example, in the second step of the intuitive workflow. The slider 150 moves from a first position to a second position. The door 234 coupled to the first arm 280 moves to cover the entrance opening 136, and the stop feature 288 coupled to the second arm 282 moves into engagement with the switch 180, moving it from a de-energized state to an energized state. Thus, the single action of providing input to the actuator 148 simultaneously provides a barrier over the entrance opening 136 and initiates an operating cycle. At this point, the mixing device 102 may be as shown in FIG. 4 , with the stop nut 272 positioned on the threaded shaft 242, proximate or adjacent to the transfer spur gear 240. The internal threads 298 of the nut portion 292 engage the threads of the threaded shaft 242. When switch 180 is energized, motor 178 provides torque from fourth spur gear 210 to transfer gear 216 through gear train 184, i.e., first, second, and third spur gears 188, 194, 200, respectively. As transfer gear 216 rotates, and with stop nut 272 prevented from rotating (by side surface 302 of flange portion 294 disposed within slot 304 in the housing), stop nut 272 translates along threaded shaft 242. Referring to FIG. 12 , flange portion 294 of stop nut 272 eventually abuts engagement member 286, and more specifically, angled surface 290 of engagement member 286. The second arm 282 of the slider 150 is configured to bend, and as the stop nut 272 translates further along the threaded shaft 242, the flange portion 294 engages the ramp surface 290, bending the second arm 282 and the engagement member 286 coupled to the second arm 282 upward. The degree of bending is such that the stop feature 288 disengages (i.e., moves upward out of interference with) the switch 180, allowing the switch 180 to automatically return to its de-energized state due to its internal bias. With the switch 180 in the de-energized state, the motor 178 ceases operation, and movement of the piston 156 and rotation of the mixing paddle 154 cease, which may be considered the end of the operating cycle.It should be appreciated that a single component, which can be molded and may be inexpensive, serves as a barrier over the inlet opening 136, initiates the operating cycle, and aborts the operating cycle.

[0065] Another embodiment for automatically terminating an operating cycle of the mixing device 102 after a predetermined period of time is described with reference to FIGS. 15 and 16. FIG. 15 shows the actuator 148 in a second position, i.e., for contacting a switch (hereinafter, the first switch 180′) after receiving an input to initiate an operating cycle. The first switch 180′ is a momentary switch that is internally biased to a de-energized state. When the actuator 148 moves from the first position to the second position, the second arm 282 translates downward through a channel 221 in the front gear train housing 218 and / or the rear gear train housing 220 and abuts against the inclined surface 223 that defines the channel 221. The second arm 282 can deflect laterally (to the left in FIG. 15 ) to contact the first switch 180′. The first switch 180′ moves from a de-energized state to a de-energized state due to mechanical force from an engagement member 286′ of the second arm 282. The second arm 282 may be restrained from resiliently bending back toward its original position by the angled surface 223 of the rear gear train housing 220. The mixing device 102 begins its operating cycle as previously described.

[0066] When the switch 180' is energized, the motor 178 provides torque from the fourth spur gear 210 to the transfer gear 216 through the gear train 184, i.e., the first, second, and third spur gears 188, 194, and 200, respectively. FIG. 16 shows a stop nut 272' in threaded engagement with the transfer gear 216, with a flange portion 294' extending laterally therefrom. As the stop nut 272' translates along the threaded shaft 242, the stop nut 272' is prevented from rotating. The mixing device 102 includes a second switch 181' separate from the first switch 180'. The second switch 181' is coupled to the housing 116 so as to be aligned with the flange portion 294' of the stop nut 272'. The second switch 181' may be a non-momentary switch that is initially energized. As the stop nut 272' translates along the threaded shaft 242, the flange portion 294' of the stop nut 272' eventually abuts the second switch 181', causing the second switch 181' to move from an energized state to a de-energized state. When the switch 181' is in a de-energized state (even though the first switch 180' remains energized), the motor 178 stops operating, causing the piston 156 to stop moving and the mixing paddle 154 to stop rotating, which can be considered the end of the operating cycle. The duration of the operating cycle can be specifically adjusted as needed. Based on the distance, the stop nut 272 must travel along the threaded shaft 242 to abut the second switch 181'.

[0067] The first switch 180' and the second switch 181' can be wired in series between the battery 176 and the motor 178. Thus, if either the first switch 180' or the second switch 181' is de-energized, the motor 178 is disabled. In the example above, the first switch 180' was initially de-energized, and the second switch 181' was initially energized. When a user input moves the actuator 148, both the first switch 180' and the second switch 181' are energized, and the motor 178 is enabled. When the stop nut 272' finally hits the second switch 181', the second switch 181' is de-energized, the first switch is energized, and the motor 178 is again disabled. This can be considered the end of the operating cycle, as the motor 178 stops operating, the piston 156 stops moving, and the mixing paddle 154 stops rotating.

[0068] As previously described, the delivery device 104 is removably coupled to the mixing device 102 to establish communication between the inlet port 106 and the outlet port 108 for transferring the bone cement mixture, and the release assembly 110 facilitates the removable coupling between the mixing device 102 and the delivery device 104. FIGS. 1 and 2 show the release assembly 110 in an initial or locked position. The release assembly 110 is configured to be movable from the initial or locked position to an unlocked position to decouple the delivery device 104 from the mixing device 102. FIGS. 17 and 19A show the release assembly 110 in the unlocked position. Referring now to FIGS. 17-20, the housing 116 includes a transfer conduit 306 in communication with the outlet port 108. As best shown in FIG. 18, the transfer conduit 306 may include a boss extending outward from the front chamber housing 164. The first end 308 of the transfer conduit 306 may include an inner wall 310 that defines the outlet port 108. Alternatively, the inner wall 310 may be coupled to a sidewall of the front chamber housing 164. The transfer conduit 306 has a length defined between a second end 309 and an opposite first end 308, the length being dimensioned to receive a sealing element 236, as shown in FIG. 19A . In particular, the sealing element 236 may be bucket-shaped with a slit or self-closing orifice (not explicitly shown) in its base 312, which is positioned adjacent to or abutting the inner wall 310 of the transfer conduit 306. The slit or self-closing orifice is configured to open upon receiving sufficiently high pressure from the bone cement mixture in the chamber 112, particularly during the compression and transfer phases of the operating cycle. In contrast, during the mixing phase of the operating cycle, which is performed at or near atmospheric pressure, the slit or self-closing orifice may prevent premature outflow of the bone cement components or mixture. The sealing element 236 may include at least one sidewall 314 extending from the base 312 and terminating near the second end 309 of the transfer conduit 306 .The inner diameter, at least partially defined by the side wall 314, is sized to removably receive a complementary male component of the delivery device 104 to provide sealed fluid communication between the outlet port 108 of the mixing device 102 and the inlet port 106 of the delivery device 104.

[0069] 18 and 19A , the transfer conduit 306 may include a first mating feature 316 and / or a second mating feature 318 configured to selectively engage complementary features of the release assembly 110, as described, to facilitate desired movement and operation of the release assembly 110. The first mating feature 316 may be a rib 320 extending along the outer surface of the transfer conduit 306, specifically extending between the first end 308 and the second end 309. FIGS. 18 and 19A , when viewed together, show two ribs 320 positioned diametrically opposite one another. The first mating feature 316 is configured to provide an interference, in a manner as described, to limit the range of movement of the release assembly 110 relative to the transfer conduit 306. In one example, the maximum range of movement is a 90-degree counterclockwise rotation, as shown in FIG. 17 , for example, relative to FIG. 1 . The second coupling feature 318 may include a rib 322 extending along the outer surface of the transfer conduit 306, particularly subtending an arc at or near the second end 309. FIGS. 18 and 19A show two ribs 322 positioned diametrically opposite one another. The ribs 322 are configured to axially retain the release assembly 110 on the transfer conduit 306. Additionally, the transfer conduit 306 may include at least one defeatable feature 324 (identified as hidden but not shown in FIG. 19A ), such as a protrusion or ridge-like structure extending outward from the outer surface of the transfer conduit 306. The defeatable feature 324 may be positioned adjacent to (behind) one or both of the ribs 322 forming the second coupling feature 318. The defeatable feature 324 is configured to maintain the release assembly 110 in the locked position to prevent inadvertent unlocking of the delivery device 104 from the mixing device 102. When input from a user is provided to the release assembly 110 with an appropriate force to overcome the interference engagement of the defeatable feature 324, the release assembly 110 can be moved to the unlocked position.

[0070] The release assembly 110 will be described with reference to FIGS. 19A and 20 . The release assembly 110 includes a head portion 326 and a body portion 328 coupled to the head portion 326. The head portion 326 may be generally tubular in shape and may include at least one sidewall 330 defining a lumen 332. The inner diameter of the lumen 332 is slightly larger than the outer diameter of the transfer conduit 306 such that the head portion 326 receives the transfer conduit 306 into the lumen 332, as shown in FIG. 19A . The head portion 326 includes at least one protrusion 334 extending inward from the sidewall 330 and disposed within the lumen 332. The at least one protrusion 334 may be two protrusions (one shown) disposed diametrically opposite one another. The protrusion 334 is configured to cooperate with the first coupling feature 316, i.e., the rib 320, to limit the range of motion of the release assembly 110. 19A shows one of the protrusions 334 engaging one of the ribs 320 when the release assembly 110 is in an unlocked configuration such that the release assembly 110 has a maximum range of motion of 90 degrees counterclockwise relative to the locked configuration. Additionally, the protrusion 334 selectively engages the second coupling feature 318, i.e., the rib 322, to prevent the release assembly 110 from being axially removed from the transfer conduit 306. More specifically, during assembly of the mixing device 102, prior to coupling the upper shell 120 of the housing 116 and the lower shell 122 of the housing 116, the protrusion 334 is guided through a gap defined between the ribs 322 that form the second coupling feature 318. At this time, the release assembly 110 is in an exaggerated clockwise orientation relative to the locked position. The release assembly 110 is rotated counterclockwise so that the protrusion 334 assumes a position behind the rib 322 and the upper shell 120 of the housing 116 together with the lower shell 122 of the housing 116. The interference between the body portion 328 of the release assembly 110 and the upper shell 120 of the housing 116 prevents clockwise rotation of the release assembly 110, and the protrusion 334 may again align with the gap (thereby allowing the release assembly 110 to be removed axially).When the body portion 328 of the release assembly 110 rests in a recess 336 defined in the upper shell of the housing 116 (see FIG. 17), the release assembly 110 may be considered to be in a locked position.

[0071] Another embodiment of the transfer conduit 306' is shown in FIG. 19B. The transfer conduit 306' includes a boss 311 extending from an inner wall 310'. The boss 311 can be coaxially disposed within a head portion 326'. The boss 311 includes a sidewall 314' that defines an inner cavity that communicates with the chamber 112 of the mixing device 102. The annular space between the boss 311 and the head portion 326' can be dimensioned to accommodate a sealing element (not shown), which in this embodiment is coupled to the delivery device 104. The head portion 326' can include a second coupling feature 318', specifically a rib 321 extending along the inner surface of the transfer conduit 306'. The rib 321 can be helical in configuration to define a groove 323 that is helical in shape. The groove 323 forms an internal thread configured to threadingly engage with an external thread (not shown) disposed on the delivery device 104. More specifically, when the release assembly 110 is rotated from the unlocked position to the locked position, for example, during assembly and packaging of the system 100, the groove 323 rotates to draw the delivery device 104 toward the mixing device 102, thereby ensuring a sealing engagement between the two. This sealing engagement further prevents the delivery device 104 from inadvertently unlocking from the mixing device 102. When the release assembly 110 is rotated from the locked position to the unlocked position, for example, prior to deploying the delivery device 104, the groove 323 rotates to move the delivery device 104 away from the mixing device 102.

[0072] The body portion 328 can be an elongated structure extending from the head portion 326. FIG. 20 shows the body portion 328 including two legs 338 that form a roughly right angle. One of the legs 338 includes a control surface 340 configured to receive input from a user. One of the legs 338 can also include indicia 342, in this case the number "3," which can correspond to a third step of the intuitive workflow. The third step of the workflow occurs after completion of the second step of the intuitive workflow, i.e., after completion of the operating cycle of the mixing device 102, which includes the transfer stage in which the bone cement mixture is transferred to the delivery device 104. When it is desired to disconnect the delivery device 104 from the mixing device 102, the user provides input to the control surface 340 to move the release assembly 110 from the locked position to the unlocked position. In particular, the release assembly 110 is rotated counterclockwise relative to the transfer conduit 306, during which the protrusion 334 abuts the defeatable feature 324. A further input is applied with sufficient force to overcome the interference engagement of the defeatable feature 324 and the release assembly 110 moves to the unlocked position shown in Figures 17, 19A and 19B.

[0073] FIG. 20 , taken in conjunction with FIG. 1 , generally illustrates the release assembly 110 in the locked position. The head portion 326 of the release assembly 110 includes a lip 344 that extends axially outward and subtends an arc such that a gap is defined between two edges 346 of the lip 344. The gap can be dimensioned to be at least equal to the width of a complementary mating feature of the delivery device 104 (e.g., a boss extending from the housing 118 and at least partially defining the inlet port 106). The lip 344 and head portion 326 define a groove 348 that extends at least substantially circumferentially between each edge 346 of the lip 344. The groove 348 includes a first groove portion 350 and second groove portions 352 (one shown) disposed on either side of the first groove portion 350. The first groove portion 350 is wider than the second groove portion 352. The second groove portion 352 is sized and configured to retain complementary mating features (e.g., radially opposed tabs extending from a boss) on the delivery device 104. The tabs on the delivery device 104 can be positioned at the 6 o'clock and 12 o'clock positions when the delivery device 104 is mated with the release assembly 110 to prevent the delivery device 104 from axially separating or slipping radially through the gap.

[0074] When the release assembly 110 is in the unlocked position, the first groove portion 350 is aligned with one of the tabs on the delivery device 104, and the gap is aligned with the other of the tabs on the delivery device 104. The relatively large width of the first groove portion 350 allows the delivery device 104 to move axially some distance relative to the release assembly 110 when the first groove portion 350 is positioned at the 6 o'clock position (see FIG. 19A ). Together, the gap is positioned at the 12 o'clock position, allowing the delivery device 104 to be manipulated upwardly relative to the release assembly 110 to decouple the delivery device 104 from the release assembly 110 and the mixing device 102. Another input is provided to the control surface 115 of the cradle 114 to allow the housing 118 of the delivery device 104 to be removed from the cradle 114.

[0075] The mixing delivery system 100 offers several advantages in the operating room. First, the mixing device 102 and delivery device 104 can be efficiently packaged. Referring now to FIGS. 19 and 20, a kit including the mixing device 102 and delivery device 104 is shown. The kit may further include packaging, for example, a blister pack 354 having a base 356 and a cover 358. The base 356 may be a thermoformed plastic that is roughly contoured to fit the mixing delivery system 100, and the cover 358 may be a release film bonded to the base 356 with an adhesive. The space-conscious manner in which the mixing device 102 and delivery device 104 are disposed within the base 356 of the blister pack 354 can accommodate conveniently containing the bone cement components (i.e., liquid monomer 360 (see FIG. 25) and powdered polymer 362) within the blister pack 354. The entire contents of the blister pack 354 may be sterile before the blister pack is opened. Thus, a surgical technician need only pass the blister pack 354 across the sterile barrier of an operating room, for example, without having to separately remove each of the mixing device 102, delivery device 104, liquid monomer 360, and powdered polymer 362. Alternatively, the blister pack 354 may include a packaging insert, such as a thermoformed tray, to protect the cover 358 from damage due to contact with the mixed delivery system 100. The packaging insert may include features that hold the liquid monomer 360 and powdered polymer 362 and allow them to be transferred to the sterile field in one step. Additionally, the mixed delivery device 100, liquid monomer 360, and powdered polymer 362 may be placed in an inner blister tray covered by the tray insert, and all of these may be transferred to the sterile field in one step. Passing fewer items across the sterile barrier increases efficiency and reduces the chance of contaminating the sterile field. In another example, the liquid monomer 360 and powdered polymer 362 may be directly coupled to the mixing device so that they can be removed from the packaging with the rest of the mixed delivery device 100 as a single unit. In another example, the powdered polymer 362 can be placed in the chamber 112 .This arrangement eliminates the steps of transferring the powdered polymer 362 to the sterile field and introducing the powder through the funnel device 138. Additionally, the liquid monomer 360 can be contained in a container (e.g., a syringe, foil pouch, or administration device) that allows direct communication with the chamber 112, thereby eliminating the need for a funnel device.

[0076] Second, as previously described, arranging the mixing device 102 and the delivery device 104 side-by-side allows the mixing device 102 and the delivery device 104 to be compactly packaged in a coupled configuration prior to deployment in a surgical suite. Referring again to FIG. 1 , the mixing device 102 includes a longitudinal axis LAM of the chamber 112, as previously described with reference to FIGS. 4 and 5 . Additionally, the delivery device 104 includes a longitudinal axis LAD. The longitudinal axis LAD of the delivery device 104 may be generally defined between the ends of the housing 118 of the delivery device 104 and / or may be coaxial with the chamber of the delivery device 104. As can be generally understood from FIG. 1 , when the delivery device 104 is coupled to the mixing device 102, the respective longitudinal axes LAD, LAM are parallel. The parallel arrangement of the respective longitudinal axes LAD, LAM allows for the efficient packaging described above. To facilitate this parallel arrangement, the outlet port 108 defined by the transfer conduit 306 (and the inlet port 106 of the delivery device 104) is disposed perpendicular to the respective longitudinal axes LAD, LAM. In other words, the bone cement mixture initially traveling within the chamber 112 along the longitudinal axis LAM is generally directed laterally through the outlet port 108 toward the inlet port 106 of the delivery device 104. The bone cement mixture can then be generally directed laterally to travel within the chamber of the delivery device 104 along the longitudinal axis LAD. Furthermore, when the delivery device 104 is coupled to the mixing device 102, the respective longitudinal axes LAD, LAM are substantially in the same horizontal plane to achieve the aforementioned parallel arrangement. The parallel and side-by-side arrangement allows the lengths of the respective housings 116, 118 to be approximately equal (when viewed in a plan view) in the coupled configuration. In other words, the structures of the mixing device 102 and the delivery device 104 rarely, if ever, extend beyond each other, thereby minimizing the need for unnecessary containment in the corresponding packaging.

[0077] FIG. 22 shows the mixing delivery system 100 within the base 356 of the blister pack 354, and FIG. 23 shows the mixing delivery system 100 being removed as a unit from the base 356 with one hand, which is the user's left hand (LH). Additionally, the flexible connection 142 allows the funnel device 138, along with the mixing device 102 and delivery device 104, to be moved with one hand. Furthermore, packaging the mixing delivery system 100 in a coupled configuration prior to deployment in the operating room allows the user to immediately use the system 100 without having to couple the delivery device 104 to the mixing device 102 before or after the start of the surgical procedure. The risk of user error is minimized, and the user can be confident that a closed, sealed system is formed between the delivery device 104 and the mixing device 102.

[0078] Once the mixing delivery system 100 is in the sterile field of an operating room, a user can initiate a three-step intuitive workflow, as generally shown in FIGS. 22 and 23 . The first step involves the user inverting the funnel device 138 and placing it into the bore 135, as indicated by the indicia 144 on the funnel device 138, which is the number “1.” The number “1” indicia may also be included on the housing 116, preferably near the bore 135, to help inform the user where to insert the funnel device 138. The user introduces the liquid monomer 360 and the powdered polymer 362 into the funnel device 138, such that they are directed to the chamber 112 within the mixing device 102. The second step involves the user providing an input to the actuator 148, e.g., moving the slider 150 from a first position to a second position, as indicated by the indicia 152 on the actuator 148, which is the number “2.” By moving the actuator 148, in the manner described in detail above, the mixing device 102 automatically executes an operating cycle by mixing the bone cement components at atmospheric pressure and then compressing and transporting the bone cement mixture in a self-sealing manner. Furthermore, the mixing device 102 automatically de-energizes to complete the operating cycle after a predetermined period based on the completion of the mixing, compressing, and transporting phases. The de-energization of the mixing device 102 indicates the completion of step 2 of the intuitive workflow. A user can recognize the de-energization of the mixing device 102 based on the elapsed time (e.g., less than one minute or more than one minute) and / or the absence of noise that may be associated with the motor 178, gear train 184, etc. As indicated by indicia 342 on the release assembly 110, which is numbered “3,” the third step of the intuitive workflow involves providing an input to the release assembly 110 to move it from a locked position to an unlocked position, thereby allowing the delivery device 104 to decouple from the mixing device 102. The delivery device 104 is ready for use as shown in FIG.

[0079] Although the bone cement mixture has been described as including a liquid monomer component and a powdered polymer component, other exemplary bone cement components can be mixed by the above-described methods and systems, including those including more than two components, those including two liquid components, or those including one or more paste components. In addition, the above-described systems and methods can also be used to deliver mixtures other than bone cement, such as bone graft materials, biological agents, other hardenable substances, and combinations thereof.

[0080] It is further contemplated that many modifications and variations are possible in light of the above teachings and that the invention may be practiced otherwise than as specifically described. By way of example, referring to FIG. 26 , a mixing and delivery system 100 is shown including stylized embodiments of a mixing device 102 and a delivery device 104. The delivery device 104 may be the same as or similar to that shown in FIG. 1 , as disclosed in the aforementioned International Publication No. 2019 / 200091 or the aforementioned U.S. Patent No. 6,547,432, among others. Alternatively, the delivery device 104 may include a hydraulic mechanism, in which the mixing device 102 transfers bone cement to a cartridge that can be pressurized by a hydraulic pump.

[0081] The mixing device 102 may include internal structure and operation similar in many respects to the previously discussed embodiments, with only certain variations described for brevity. With continued reference to FIG. 26 , a funnel device 138 may be integrated into the housing 116. In particular, the upper shell 120 of the housing 116 defines a funnel 138′, which is a sloped surface 139 extending downward from the upper surface. The funnel 138′ communicates with an aperture (not shown) that leads to a chamber (not shown). The integration of the funnel 138′ further reduces the footprint of the mixing device 102, and therefore the footprint of the mixing delivery system 100. The reduced footprint may simplify packaging and consume less space in the operating room. Furthermore, the integration of the funnel 138′ may simplify user workflow by eliminating the need for the user to insert the funnel device 138 of FIG. 1 into the aperture 135.

[0082] The release assembly 110 of the mixing device 102 may be a button 364, as opposed to the lever previously described. FIG. 27 shows a button 364, many of which are known and marked "eject," located on the top surface of the upper shell 122 of the housing 116. The button 364 can be actuated, and an internal mechanism (not shown) of the release assembly coupled to the button 364 can move the system 100 from an initial or locked position to an unlocked position, allowing the delivery device 104 to decouple from the mixing device 102. As the release assembly 110 moves the system 100 from the initial or locked position to the unlocked position, the internal mechanism can further be configured to move a portion of the delivery device 104 slightly away from the mixing device 102 to visually indicate that the delivery device 104 is no longer docked and that it is appropriate to completely remove the delivery device 104 for use.

[0083] In one embodiment, the release or "undocking" of the delivery device 104 from the mixing device 102 can be based on the movement of one or more components of the mixing device 102. For example, a mechanical, electromechanical, or electrical actuator(s) can detect when the piston 156 is in a position within the second region 160 of the chamber 112 that indicates the completion of the compression and transfer stages. Based on this position, the actuator(s) move the system 100 from a locked position to an unlocked position and / or move a portion of the delivery device 104 slightly away from the mixing device 102.

[0084] The mixing device 102 may include a display 366, e.g., a digital numeric display. The display 366 is shown disposed on the front surface of the upper shell 120, although other suitable locations are contemplated. The display 366 is configured to provide a user with information regarding the operation of the system 100, and more particularly, the operation of the mixing device 102. In one example, the display 366 displays the remaining time of an operating cycle. In other words, the display 366 counts down from the initial time to zero. In another example, the display 366 displays the elapsed time of an operating cycle. In other words, the display 366 counts up from zero. In yet another example, the display 366 displays an estimate of the remaining working time of the bone cement. A temperature sensor (not shown) may be included in the mixing device 102. Because the total working time of the bone cement depends on the external temperature, an algorithm can be stored in memory (not shown) for determining the total working time of the bone cement based on the temperature (e.g., room temperature) sensed by the temperature sensor. In combination with a timer function, the processor can determine the remaining working time as the difference between the total working time and the elapsed working time. In addition to the display 366 displaying the remaining work time numerically, other types of visual indicia may be presented. The display 366 may change color (e.g., green, yellow, red) when the remaining work time falls below a predetermined threshold. Similarly, the display 366 may flash and / or emit an audible alarm. Additionally, the timer may be a series of lights, a moving bar, an analog clock, etc.

[0085] In some embodiments, the display 366 can be configured to selectively or automatically transition between information related to the operation of the mixing device 102 or bone cement. For example, the display 366 can provide a first output including the time remaining in the operating cycle, as described above. Then, after reaching zero, the display 366 can automatically transition from the first output to a second output including counting up from zero to indicate the elapsed operating time. A user can selectively switch between the first input, the second input, and / or any additional inputs.

[0086] The mixing device 102 may include at least one indicator light 368, 370, 372 to enhance usability. In at least some respects, the indicator lights 368, 370, 372 may be similar to the indicia 146, 152, 342 (see FIGS. 2 and 20 ) for guiding a user through a workflow. The first indicator light 368 may be located near, on, near, or around the funnel device 138 and thus corresponds to directing bone cement components through the funnel device 138 into the chamber 112. The second indicator light 370 may be located near, on, near, or around the power button 374 and thus corresponds to operating the mixing device 102 to begin an operating cycle. The third indicator light 372 may be located near, on, near, or around the button 364 and thus corresponds to transitioning the release assembly 110 from a locked configuration to an unlocked configuration. The indicator lights 368, 370, 372 may be light emitting diodes (LEDs) or other suitable indicator lights.

[0087] The indicator lights 368, 370, 372 can be connected to a controller or processor. Based on some actions, the controller can selectively control one or more of the indicator lights 368, 370, 372 to illuminate to notify the user what to do next. In one workflow, the power button 374 can be actuated to turn on the mixing device 102, i.e., to wake the mixing device 102 from a sleep-like state. The controller sends a signal to illuminate the first indicator light 368 because directing the bone cement components into the chamber 112 through the funnel device 138 can be the first step in the workflow. The first indicator light 368 can remain illuminated until sensors connected to the controller (e.g., a load sensor in the chamber 112 and an optical sensor near the hole 135) detect that the bone cement components have been directed into the chamber 112. The controller sends a corresponding signal to turn off the first indicator light 368 and turn on the second indicator light 370 based on the signal received from the sensor, since pressing the power button 374 can be the second step in the workflow. The mixing device 102 begins the blending, compressing, and transporting phases of the operating cycle described above. The display 366 can present information regarding the status of the operating cycle. Upon completion, the controller sends a corresponding signal to turn off the second indicator light 370 and turn on the third indicator light 372, since transitioning the release assembly 110 from the locked configuration to the unlocked configuration can be the third step in the workflow. The user can press the button 364 to remove the delivery device 104 from the mixing device 102. Once the button 364 is pressed, the display 366 can begin displaying the remaining working time as the difference between the total working time and the elapsed working time, for example, based on the room temperature.

[0088] Some implementations can be described with reference to the following exemplary clauses.

[0089] Clause 1 - A method for making bone cement using a mixing device including a chamber defining an entrance opening, the chamber including a first end opposite a second end, the entrance opening being between the first end and the second end, the mixing device further including a piston disposed within the chamber and a mixing paddle disposed within the chamber, the method comprising: mixing bone cement components using the mixing paddle at a first pressure to make a bone cement mixture when a face of the piston is located within a first region of the chamber extending longitudinally between the first end of the chamber and the entrance opening; and moving the piston toward the second end of the chamber so that the face of the piston is past the entrance opening and located within the second region of the chamber to compress the bone cement mixture at a second pressure greater than the first pressure.

[0090] Clause 2 - The method of clause 1, wherein the first pressure is atmospheric pressure.

[0091] Clause 3 - The method of clause 1 or 2, further comprising forming a fluid-tight closure between the piston and the chamber in the second region.

[0092] Clause 4 - The method of any one of clauses 1 to 3, wherein the chamber further defines an outlet port adjacent a second end of the chamber, and the step of moving the piston further includes moving the piston along the longitudinal axis within the second region to force the bone cement out of the mixing device through the outlet port.

[0093] Clause 5 - The method of any one of clauses 1-4, further comprising rotating a mixing paddle to mix the bone cement components in the chamber.

[0094] Clause 6 - The method of any one of clauses 1 to 5, further comprising bending the mixing paddle with forces associated with the piston moving along the longitudinal axis and with forces associated with the inner surface of the housing defining the second end of the chamber.

[0095] Clause 7 - A method of making bone cement using a mixing device and transferring the bone cement to a delivery device coupled to the mixing device, the mixing device including a chamber defining an entrance opening, a piston disposed within the chamber, a mixing paddle disposed within the chamber, a motor coupled to the piston and the mixing paddle, an actuator coupled to the housing, and a door coupled to the actuator, the method including the steps of: introducing at least two bone cement components into the chamber through the entrance opening; moving the actuator from a first position to a second position to cover the entrance opening with the door; and simultaneously activating the motor while the piston is within the first region, wherein activating the motor rotates the mixing paddle to mix the at least two bone cement components in the chamber at atmospheric pressure to form a bone cement mixture; and moving the piston through the entrance opening into a second region of the chamber to (i) compress the bone cement mixture at a second pressure greater than atmospheric pressure; and (ii) transfer the bone cement to the delivery device.

[0096] Clause 8 - The method of clause 7, wherein the mixing device further includes a release assembly that couples the mixing device to the delivery device, and the method further includes providing an input that moves the release assembly from a locked position in which an orientation feature of the release assembly engages with a complementary orientation feature of the delivery device to an unlocked position in which the orientation feature and the complementary orientation feature are disengaged, allowing the delivery device to be disconnected from the mixing device.

[0097] Clause 9 - The method of clause 7 or 8, wherein the at least two bone cement components are a liquid monomer and a powdered polymer, and the step of introducing the bone cement components into the chamber further includes directing both the liquid monomer and the powdered polymer through the inlet opening.

[0098] Clause 10 - A mixing device for making bone cement, comprising: a housing; a chamber within the housing, the chamber having a first region and a second region distinct from the first region; a mixing paddle rotatable within the chamber for mixing bone cement components to make a bone cement mixture; a piston movable within the chamber for compressing the bone cement components; a motor coupled to the piston and the mixing paddle; and a switch connected to the motor, the switch transitioning between an energized state in which the switch initiates an operating cycle by actuating the motor to move at least one of the piston and rotate the mixing paddle, and a de-energized state in which the switch terminates an operating cycle by de-energizing the motor. a switch configured to energize a piston in a chamber such that the switch is biased toward a de-energized state; and an actuator coupled to the housing, the actuator movable between a first position in which the actuator is spaced from the switch and a second position in which the actuator engages the switch to transition the switch from the de-energized state to an energized state and to maintain the switch in an energized state against the bias, the piston configured to move within the chamber from the first region to the second region such that when the piston is in the second region, the actuator is mechanically decoupled from the switch to bias the switch back from the energized state to the de-energized state.

[0099] Clause 11 - A mixing device as described in clause 10, wherein the switch is a momentary switch.

[0100] Clause 12 - The mixing device of clause 10 or 11, further comprising: a transfer gear coupled to the motor and rotatable during an operating cycle; and a stop nut coupled to the transfer gear, the stop nut being rotationally constrained relative to the transfer gear so as to translate along the transfer gear and engage the actuator to mechanically disengage the actuator from the switch.

[0101] Clause 13 - The mixing device of clause 12, wherein the stop nut further comprises a nut portion having an inner diameter that threadably engages an outer diameter of the transfer gear, and a flange portion extending from the nut portion, the flange portion configured to engage the actuator to mechanically decouple the actuator from the switch.

[0102] Clause 14 - A mixing device according to any one of clauses 10 to 13, wherein the actuator is a slider comprising a slider body, an arm extending from a lower surface of the slider body, and a stop feature coupled to the arm and configured to engage the switch.

[0103] Clause 15 - A mixing device as described in clause 14, wherein the slider further comprises an inclined surface coupled to the arm and positioned for engagement by the stop nut when the stop nut is translated by rotation of the transfer gear, wherein engagement of the stop nut with the inclined surface imparts a bending to the arm and disengages the stop feature from the switch.

[0104] Clause 16 - A mixing device for making bone cement, comprising: a housing; a chamber within the housing, the chamber having a first region and a second region distinct from the first region; a mixing paddle rotatable within the chamber for mixing bone cement components to make a bone cement mixture; a piston movable within the chamber for compressing the bone cement components; a motor coupled to the piston and the mixing paddle; a switch connected to the motor, the switch configured to transition between an energized state in which the switch initiates an operating cycle by actuating the motor to move at least one of the piston and rotate the mixing paddle, and a de-energized state in which the switch terminates an operating cycle by de-energizing the motor, the switch being momentary and biased toward the de-energized state; and an actuator coupled to the housing, the actuator movable between a first position in which the actuator is spaced from the switch and a second position in which the actuator engages the switch to transition the switch from the de-energized state to an energized state and maintain the switch in the energized state against the bias.

[0105] The above disclosure is not intended to be exhaustive or to limit the invention to any particular form, and the terminology used is intended to be words of description rather than of limitation in nature. The scope of the patent claims at the time of filing is as follows: [Claim 1] 1. A mixing device for making a bone cement from bone cement components, said mixing device comprising: Housing and a chamber within the housing and defining an inlet opening, the chamber having first and second ends and a longitudinal axis extending between the first and second ends, a first region of the chamber defined longitudinally between the first end of the chamber and an end of the inlet opening closest to the second end of the chamber, and a second region of the chamber defined longitudinally between the first region of the chamber and the second end; a piston disposed within the chamber and having a face; a mixing paddle rotatable within the chamber; the face of the piston is configured to be located within the first region of the chamber such that the chamber is at subatmospheric pressure when the mixing paddle rotates to mix the bone cement components to form a bone cement mixture; The piston is configured to be movable along the longitudinal axis to position the surface within the second region of the chamber to form a fluid-tight closure between the piston and the chamber, such that further movement of the piston within the second region compresses the bone cement mixture within the chamber. [Claim 2] 10. The mixing device of claim 1, further comprising a motor operably coupled to the piston and the mixing paddle, the motor configured to at least one of move the piston and rotate the mixing paddle. [Claim 3] 3. The mixing device of claim 1 or 2, wherein the chamber further defines an outlet port adjacent the second end of the chamber. [Claim 4] 4. The mixing device of claim 3, further comprising a first switch coupled to the housing and connected to the motor, the first switch being transitionable to an energized state in which the first switch activates the motor while the piston is within the first region. [Claim 5] 5. The mixing device of claim 4, further comprising a second switch coupled to the housing and connected to the motor, the second switch being movable to a de-energized state that prevents the second switch from operating the motor while the piston is within the second region. [Claim 6] 6. The mixing device of claim 4 or 5, wherein the first switch is a momentary switch biased toward the non-energized state. [Claim 7] 6. The mixing device of claim 5, wherein the first switch and the second switch are wired in series with the motor. [Claim 8] 8. The mixing device of claim 4, further comprising an actuator coupled to the housing and movable to engage the first switch to maintain the first switch in the energized state. [Claim 9] a rotatable transfer gear coupled to the motor; a stop nut configured to move along the transfer gear and engage the second switch while the piston is in the second region; and The mixing device of claim 5 further comprising: [Claim 10] 1. A mixing device for making bone cement, said mixing device comprising: Housing and a chamber within the housing; and a mixing paddle rotatable within the chamber to mix the bone cement components to form a bone cement mixture; a piston movable within the chamber for compressing the bone cement component; a motor coupled to the piston and the mixing paddle; a switch connected to the motor, the switch being momentary and biased to a de-energized state that prevents activation of the motor, the switch being configured to transition from the de-energized state to an energized state that activates the motor to initiate an operating cycle by at least one of moving the piston and rotating the mixing paddle; A mixing device wherein the piston is configured to move within the chamber from a first region to a second region to mix and compress the bone cement mixture within the chamber, the piston being within the first region during activation of the first switch. [Claim 11] 11. The mixing device of claim 10, wherein the switch is a first switch, the mixing device comprises a second switch wired in series with the first switch and the motor, the second switch being non-momentary and initially disposed in an energized state to allow activation of the motor, the second switch being configured to transition from the energized state to a de-energized state that disables activation of the motor and terminates the operating cycle, and the piston is within the second region during activation of the second switch. [Claim 12] 12. The mixing device of claim 10 or 11, wherein the chamber is at sub-atmospheric pressure when the piston is in the first region and above atmospheric pressure when the piston is in the second region. [Claim 13] 13. The mixing device of claim 11 or 12, further comprising an actuator coupled to the housing and movable between a first position spaced from the first switch and a second position that engages and activates the first switch. [Claim 14] 1. A mixing device for making bone cement, said mixing device comprising: Housing and a chamber within the housing defining an entrance opening configured to receive a bone cement component; a mixing paddle rotatable within the chamber to mix the bone cement components to form a bone cement mixture; a piston movable within the chamber for compressing the bone cement component; a motor coupled to the piston and the mixing paddle; a switch mounted on the housing and connected to the motor, the switch being initially in a de-energized state; an actuator coupled to the housing, the actuator movable between a first position in which the actuator is spaced from the first switch and the entrance opening is open to the environment, and a second position in which the actuator engages the first switch to transition the first switch from the de-energized state to the energized state; A mixing device comprising: [Claim 15] The switch is a first switch, and the mixing device is a second switch mounted on the housing and spaced apart from the first switch, the second switch being initially in an energized state, the first switch and the second switch being wired in series with the motor; and a stop nut movable into engagement with the second switch to transition the second switch from the energized state to the de-energized state; 15. The mixing device of claim 14, further comprising: [Claim 16] 16. The mixing device of claim 15, wherein the actuator is a slider comprising a slider body and an arm extending from a lower surface of the slider body, the arm configured to move into engagement with the first switch. [Claim 17] 17. The mixing device of claim 15 or 16, wherein the first switch and the second switch are mounted directly to the housing at separate locations without being coupled to a printed circuit board. [Claim 18] 1. A mixing device for making bone cement, said mixing device comprising: Housing and a chamber within the housing defining an entrance opening configured to receive a bone cement component; a mixing paddle rotatable within the chamber to mix the bone cement components to form a bone cement mixture; a piston movable within the chamber for compressing the bone cement component; a motor coupled to the piston and the mixing paddle; a switch connected to the motor; an actuator coupled to the housing, the actuator being movable between a first position in which the actuator is spaced from the switch and the inlet opening is open to the environment, and a second position in which the actuator engages the switch and simultaneously (i) transitions the switch from a de-energized state to an energized state in which the switch begins an operating cycle by actuating the motor to move at least one of the piston and rotate the mixing paddle, and (ii) closes the inlet opening; A mixing device comprising: [Claim 19] a funnel device having a flared portion and a stem sized to be received within the inlet opening of the chamber; a flexible connection connecting the funnel device to the housing; 20. The mixing device of claim 18, further comprising: [Claim 20] 20. The mixing device of claim 18, wherein the housing defines a bore, the inlet opening is positioned below the bore such that bone cement components guided through the bore further pass through the inlet opening into the chamber under the influence of gravity, and the actuator further comprises a door positioned to be located between the inlet opening and the bore when the actuator is in the second position. [Claim 21] a funnel device including a flared portion and a stem sized to be received within the bore of the housing; a flexible connection connecting the funnel device to the housing; 21. The mixing device of claim 19 or 20, further comprising: [Claim 22] 22. The mixing device of claim 21, wherein the funnel device further comprises a locking feature disposed on the stem and configured to releasably engage with a complementary locking feature on the housing. [Claim 23] 1. A mixing device for making bone cement, said mixing device comprising: a housing including an upper shell and a lower shell coupled to the upper shell; a chamber within the housing defining an entrance opening configured to receive a bone cement component; a mixing paddle rotatable within the chamber to mix the bone cement components to form a bone cement mixture; a piston movable within the chamber for compressing the bone cement component; a motor coupled to the piston and the mixing paddle; A mixing device wherein the upper shell comprises a funnel having a sloped surface defining a hole in communication with the inlet opening. [Claim 24] 24. The mixing device of claim 23, wherein the upper shell has an upper surface and the angled surface extends downwardly from the upper surface. [Claim 25] 25. The mixing device of claim 23 or 24, wherein the funnel is frusto-conical in shape. [Claim 26] 1. A mixing device for making bone cement, said mixing device comprising: a housing including an upper shell and a lower shell coupled to the upper shell; a chamber within the housing defining an entrance opening configured to receive a bone cement component; a mixing paddle rotatable within the chamber to mix the bone cement components to form a bone cement mixture; a piston movable within the chamber for compressing the bone cement component; a motor coupled to the piston and the mixing paddle; a display coupled to the housing and configured to display information indicative of operation of the mixing device; A mixing device comprising: [Claim 27] 27. The mixing device of claim 26, wherein the display device is a liquid crystal display (LCD), a series of indicator lights, a digital timer, or an analog timer. [Claim 28] 28. The mixing device of claim 26 or 27, wherein the information is one of a remaining time for operation of the mixing device, an elapsed time for working with the bone cement, and an estimated remaining time for working with the bone cement. [Claim 29] 1. A kit for performing a vertebral augmentation procedure using bone cement, the kit comprising: a mixing device for mixing bone cement components to form a bone cement mixture and compressing the bone cement mixture, the mixing device comprising: a chamber defining an inlet opening and an outlet port in communication with said inlet opening; a piston movable within the chamber; a mixing paddle rotatable within the chamber; a delivery device including a chamber defining an inlet port for receiving bone cement from the mixing device; a package sized to contain the mixing device and the delivery device; The inlet port of the delivery device is in communication with the outlet port of the mixing device such that the mixing device and the delivery device are removably coupled to each other within the packaging and are configured to be removed from the packaging as a single unit. [Claim 30] 30. The kit of claim 29, wherein when the mixing device and the delivery device are removably coupled to one another, a longitudinal axis of the chamber of the mixing device and a longitudinal axis of the chamber of the delivery device are parallel such that the mixing device and the delivery device are disposed in a side-by-side arrangement within the packaging. [Claim 31] 31. The kit of claim 30, wherein the outlet port of the mixing device and the inlet port of the delivery device are oriented perpendicular to their respective longitudinal axes to facilitate the side-by-side orientation. [Claim 32] 32. The kit of any one of claims 29 to 31, further comprising a funnel device and a flexible connection connecting the funnel device and the mixing device such that the funnel device is configured to be removed from the packaging as a single unit. [Claim 33] 33. The kit of any one of claims 29 to 32, further comprising a liquid monomer and a powdered polymer disposed within the package. [Claim 34] 45. The kit of any one of claims 29 to 44, wherein the packaging is a blister pack.

Claims

1. 1. A mixing device for making a bone cement from bone cement components, said mixing device comprising: Housing and a chamber within the housing, the chamber defining an inlet opening and an outlet port, the outlet port configured to be removably coupled to a delivery device to establish fluid communication between the inlet opening and the delivery device, the chamber having a first end and a second end and a longitudinal axis extending between the first end and the second end, a first region of the chamber defined longitudinally between the first end of the chamber and an end of the inlet opening closest to the second end of the chamber, and a second region of the chamber defined longitudinally between the first region of the chamber and the second end; a piston disposed within the chamber and having a face; a mixing paddle rotatable within said chamber; a motor operably coupled to the piston and the mixing paddle; the face of the piston is configured to be located within the first region of the chamber such that the chamber is at subatmospheric pressure when the mixing paddle rotates to mix the bone cement components to form a bone cement mixture; The motor is configured to move the piston along the longitudinal axis to position the surface within the second region of the chamber to form a fluid-tight closure between the piston and the chamber, such that further movement of the piston compresses the bone cement mixture in the second region of the chamber and transfers the bone cement mixture from the connection between the delivery device and the outlet port to the delivery device.

2. The mixing device of claim 1 , wherein the motor is configured to rotate the mixing paddle.

3. 3. The mixing device of claim 1 or 2, wherein the chamber further defines an outlet port adjacent the second end of the chamber.

4. 3. The mixing device of claim 2, further comprising a first switch coupled to the housing and connected to the motor, the first switch being capable of being moved to an energized state in which the first switch activates the motor.

5. 5. The mixing device of claim 4, further comprising a second switch coupled to the housing and connected to the motor, the second switch being movable to a de-energized state that prevents the second switch from operating the motor.

6. 6. The mixing device of claim 5, wherein the first switch is a momentary switch biased toward the un-energized state.

7. 6. The mixing device of claim 5, wherein the first switch and the second switch are wired in series with the motor.

8. 8. The mixing device of claim 4, further comprising an actuator coupled to the housing and movable to engage the first switch to maintain the first switch in the energized state.

9. a rotatable transfer gear coupled to the motor; a stop nut configured to move along the transfer gear and engage the second switch while the piston is in the second region; and The mixing device of claim 5 further comprising:

10. 1. A mixing device for making bone cement, said mixing device comprising: Housing and a chamber within the housing defining an inlet opening and an outlet port, the outlet port configured to be removably coupled to a delivery device to establish fluid communication between the inlet opening and the delivery device; a mixing paddle rotatable within the chamber to mix the bone cement components to form a bone cement mixture; a piston movable within the chamber for compressing the bone cement component; a motor coupled to the piston and the mixing paddle; an actuator movably coupled to the housing; a switch connected to the motor, the switch being momentary and biased to a de-energized state that prevents activation of the motor, the switch being configured by the actuator to be transitioned from the de-energized state to an energized state that activates the motor to move the piston and thereby initiate an operating cycle; A mixing device that mixes and compresses the bone cement mixture in the chamber from a first region through the inlet opening to form a fluid-tight closure between the piston and the chamber in a second region, and transfers the bone cement mixture from a connection between the delivery device and the outlet port to the delivery device, the piston being within the first region during activation of the switch.

11. 11. The mixing device of claim 10, wherein the switch is a first switch, the mixing device comprises a second switch wired in series with the first switch and the motor, the second switch being non-momentary and initially disposed in an energized state to allow activation of the motor, the second switch being configured to transition from the energized state to a de-energized state that disables activation of the motor and terminates the operating cycle, and the piston is within the second region during activation of the second switch.

12. 12. A mixing device according to claim 10 or 11, wherein the chamber is at sub-atmospheric pressure when the piston is in the first region and above atmospheric pressure when the piston is in the second region.

13. 12. The mixing device of claim 11, further comprising an actuator movable between a first position spaced from the first switch and a second position engaging and actuating the first switch.

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