Spinal alignment system with thermally actuated component

Abstract

To provide a spinal alignment system with at least one thermally actuated component.SOLUTION: A spinal adjustment system includes: a rolling bladder configured to return from a contracted state to an expanded state and from the expanded state to the contracted state; a pump supplying working fluid so that the rolling bladder expands and contracts; an accumulator in fluid communication; and a power source operable so as to selectively supply the pump with power. The pump is selectively operable so that it pumps the working fluid from a first volume to the rolling bladder so that the rolling bladder expands into the expanded state, and pumps the working fluid from the second volume to the accumulator so that the fluid is discharged to a second volume from the rolling bladder and the rolling bladder contracts into the contracted state.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 150,059, filed on February 16, 2021, entitled "SPINAL ALIGNMENT SYSTEM WITH THERMALLY ACTUATED COMPONENT", the entire content of which is incorporated herein by reference.

[0002] This application is related to U.S. Non-Provisional Patent Application No. 17 / 176,732, filed on February 16, 2021, entitled "BIDIRECTIONAL THERMALLY ACTUATED COMPONENT FOR USE IN MEDICAL DEVICES", the entire content of which is incorporated herein by reference. Field of Disclosure

[0003] The present invention relates to a spinal alignment system including a thermally actuated actuator component.

Background Art

[0004] There are various medical devices and instruments used to drive, correct, or maintain an alignment including spinal alignment. Many conventional devices are limited to manually actuated adjustment elements. Relying on human mechanical intervention poses a risk of impairment if the user is unable to make appropriate adjustments or makes inappropriate adjustments. Other devices using automatic adjustment are usually complex and prone to errors including catastrophic errors that can run amok.

[0005] Therefore, it is desirable to provide an alignment system that solves these and other problems.

Summary of the Invention

[0006] An object of the present invention is to provide a spinal alignment system that is safe and has an output restricted with respect to an input such that the output of the component is finite, thereby suppressing the risk of serious or catastrophic errors.

[0007] In an embodiment, a spinal alignment system according to an embodiment of the present disclosure includes one or more bidirectional thermally actuated components that transition between a solid and a fluid based on temperature and that may use a material that is as harmless as, for example, crayon material or paraffin wax.

[0008] In an embodiment, the system may include feedback information regarding the operation of the system to confirm that a given input has resulted in the correct output.

[0009] A spinal alignment system according to an embodiment of the present disclosure includes a rolling bladder configured to expand from a contracted state to an extended state and return from the extended state to the contracted state; and a pump connected to the rolling bladder and configured to supply a working fluid to the rolling bladder so that the rolling bladder expands to the extended state and remove the working fluid from the rolling bladder so that the rolling bladder contracts to the contracted state. The pump includes a first volume filled with a working fluid; a first pump element provided in the first volume and operable to expand when actuated to pump the working fluid from the first volume; a second volume filled with the working fluid; a second pump element provided in the second volume and operable to expand when actuated to pump the working fluid from the second volume. Here, the rolling bladder is in fluid communication with the first volume and the second volume, expands to the inflated state when the working fluid flows into the rolling bladder, and contracts when the working fluid flows out of the rolling bladder; an accumulator in fluid communication with the first volume and the second volume; and a power source electrically connected to the first pump and the second pump and operable to selectively supply power to the first pump and the second pump. Here, the first pump element expands when power is supplied to the first pump element to increase the pressure in the first volume and pump the working fluid from the first volume to the rolling bladder so that the rolling bladder expands to the extended state; the second pump element expands when power is supplied to the second pump element to increase the pressure in the second volume and pump the working fluid from the second volume to the accumulator, and contracts so that the fluid is discharged from the rolling bladder to the second volume and the rolling bladder contracts to the contracted state when the power is removed from the second pump element.

[0010] In an embodiment, the system includes a first check valve disposed between a first volume and a rolling bladder and configured to control the flow of working fluid from the first volume to the rolling bladder; a second check valve disposed between the first volume and an accumulator and configured to control the flow of working fluid between the first volume and the accumulator; a third check valve disposed between a second volume and the rolling bladder and configured to control the flow of working fluid from the rolling bladder to the second volume; and a relief valve between the second volume and the accumulator and configured to control the flow of working fluid from the second volume to the accumulator.

[0011] In an embodiment, the first check valve allows the working fluid to flow from the first volume to the rolling bladder when the first pump element expands and prevents the working fluid from flowing back into the first volume when the first pump contracts after power is removed.

[0012] In an embodiment, the second check valve allows the working fluid to flow from the accumulator into the first volume when the first pump element contracts after power is removed.

[0013] In an embodiment, the relief valve is configured to allow the working fluid to flow from the second volume to the accumulator when the second pump element expands when power is applied to the second pump element.

[0014] In an embodiment, the third check valve is configured to allow the working fluid to flow from the rolling bladder to the second volume so that the rolling bladder returns to a contracted state when the second pump contracts after power is removed.

[0015] In an embodiment, the power source is a wire coil.

[0016] In an embodiment, the system includes a power supply circuit configured to selectively supply power to one of a first pump element and a second pump element.

[0017] In an embodiment, the power supply circuit includes a first diode disposed between the wire coil and the first pump element so that power is supplied to the first power pump when a current is induced in the wire coil using a rectified sine wave signal having a first polarity; and a second diode disposed between the wire coil and the second pump element so that power is supplied to the second power pump when a current is induced in the wire coil using a rectified sine wave signal having a second polarity opposite to the first polarity.

[0018] In an embodiment, the wire coil is paired with an external wire coil such that a current is induced in the wire coil when the external wire coil is disposed adjacent to the wire coil.

[0019] In an embodiment, the rolling bladder is disposed between a first vertebra and a second vertebra such that the distance between the first vertebra and the second vertebra changes due to the inflation of the rolling bladder.

[0020] In an embodiment, the system includes another rolling bladder configured to be in fluid communication with the pump and expand in an inflated state and contract in a deflated state.

[0021] In an embodiment, the first pump includes a first bellows containing eutectic wax; and a first heating element electrically connected to a power source, the first heating element being arranged such that when power is supplied to the first heating element, the eutectic wax melts and the first bellows expands, and when power is removed from the first heating element, the eutectic wax cools and solidifies and the first bellows contracts.

[0022] In an embodiment, the second pump includes a second bellows containing a eutectic wax and a second heating element electrically connected to a power source. When power is supplied to the second heating element, the eutectic wax melts and the second bellows expands. When power is removed from the second heating element, the eutectic wax cools and solidifies and the second bellows contracts.

[0023] A spinal adjustment system according to an embodiment of the present disclosure includes a first rolling bladder configured to expand from a contracted state to an extended state and from the extended state to the contracted state; a second rolling bladder configured to expand from a contracted state to an extended state and from the extended state to the contracted state; a pump in fluid communication with the first rolling bladder and the second rolling bladder, configured to supply a working fluid to the first rolling bladder and the second rolling bladder so that the first rolling bladder and the second rolling bladder expand to the extended state, and configured to remove the working fluid from the first rolling bladder and the second rolling bladder so that the first rolling bladder and the second rolling bladder contract to the contracted state. The pump includes a first volume filled with the working fluid; a first pump element provided in the first volume and operable to expand when actuated to pump the working fluid out of the first volume; a second volume filled with the working fluid; a second pump element provided in the second volume and operable to expand when actuated to pump the working fluid out of the second volume. Here, the first rolling bladder and the second rolling bladder are in fluid communication with the first volume and the second volume, expand to the expanded state when the working fluid flows into the first rolling bladder and the second rolling bladder, and contract when the working fluid flows out of the first rolling bladder and the second rolling bladder; an accumulator in fluid communication with the first volume and the second volume; a power source electrically connected to the first pump and the second pump and operable to selectively supply power to the first pump and the second pump.including, the first pump element expands when power is supplied to the first pump element to increase the pressure within the first volume, pumping the working fluid from the first volume to the first rolling bladder and the second rolling bladder such that the first rolling bladder and the second rolling bladder expand to an extended state, the second pump element expands when power is supplied to the second pump element to increase the pressure within the second volume, pumping the working fluid from the second volume to the accumulator, and when power is removed from the second pump element, contracting such that fluid is discharged from the first rolling bladder and the second rolling bladder to the second volume and the first rolling bladder and the second rolling bladder contract to a contracted state.;

[0024] In an embodiment, the system includes a first check valve disposed between the first volume and the first rolling bladder and the second rolling bladder and configured to control the flow of working fluid from the first volume to the first rolling bladder and the second rolling bladder; a second check valve disposed between the first volume and the accumulator and configured to control the flow of working fluid between the first volume and the accumulator; a third check valve disposed between the second volume and the first rolling bladder and the second rolling bladder and configured to control the flow of working fluid from the first rolling bladder and the second rolling bladder to the second volume; and a relief valve disposed between the second volume and the accumulator and configured to control the flow of working fluid from the second volume to the accumulator.

[0025] In an embodiment, the first check valve allows the working fluid to flow from the first volume to the first rolling bladder and the second rolling bladder when the first pump element expands and prevents the working fluid from flowing back into the first volume when the first pump contracts after power is removed.

[0026] In an embodiment, the second check valve allows the working fluid to flow from the accumulator into the first volume when the first pump element contracts after power is removed.

[0027] In an embodiment, when power is applied to the second pump element and the second pump element expands, the relief valve is configured to allow the working fluid to flow from the second volume to the accumulator.

[0028] In an embodiment, when power is removed and the second pump contracts, the third check valve is configured to allow the working fluid to flow from the first rolling bladder and the second rolling bladder to the second volume so that the first rolling bladder and the second rolling bladder return to a contracted state.

[0029] In an embodiment, the power source is a wire coil.

[0030] In an embodiment, the system includes a power supply circuit configured to selectively supply power to one of the first pump element and the second pump element.

[0031] In an embodiment, the power supply circuit includes a first diode disposed between the wire coil and the first pump element so that power is supplied to the first power pump when a current is induced in the wire coil using a rectified sine wave signal having a first polarity; and a second diode disposed between the wire coil and the second pump element so that power is supplied to the second power pump when a current is induced in the wire coil using a rectified sine wave signal having a second polarity opposite to the first polarity.

[0032] A spinal adjustment system according to an embodiment of the present disclosure includes a first rolling bladder configured to expand from a contracted state to an extended state and from an extended state to a contracted state; a first pump in fluid communication with the first rolling bladder and configured to supply working fluid to the first rolling bladder so that the first rolling bladder expands to the extended state and remove the working fluid from the first rolling bladder so that the first rolling bladder contracts to the contracted state. The first pump includes a first volume filled with the working fluid; a first pump element provided in the first volume and operable to expand when actuated to pump the working fluid from the first volume; a second volume filled with the working fluid; a second pump element provided in the second volume and operable to expand when actuated to pump the working fluid from the second volume. Here, the first rolling bladder is in fluid communication with the first volume and the second volume, expands to the inflated state when the working fluid flows into the first rolling bladder, and contracts when the working fluid flows out of the first rolling bladder; an accumulator in fluid communication with the first volume and the second volume; a power source electrically connected to the first pump element and the second pump element and operable to selectively supply power to the first pump element and the second pump element. The first pump element expands when power is supplied to the first pump element to increase the pressure in the first volume and pump the working fluid from the first volume to the first rolling bladder so that the first rolling bladder expands to the extended state. The second pump element expands when power is supplied to the second pump element to increase the pressure in the second volume and pump the working fluid from the second volume to the accumulator. When power is removed from the second pump element, the fluid is discharged from the first rolling bladder to the second volume and the first rolling bladder contracts to the contracted state. A first pump that contracts; a second rolling bladder configured to expand from a contracted state to an extended state and from an extended state to a contracted state;A second pump configured to be in fluid communication with the second rolling bladder and supply hydraulic fluid to the second rolling bladder so that the first rolling bladder extends to an extended state and remove hydraulic fluid from the second rolling bladder so that the second rolling bladder contracts to a contracted state, the second pump including: a third volume filled with hydraulic fluid; a third pump element provided within the third volume and operable to expand when actuated to pump hydraulic fluid from the third volume; a fourth volume filled with hydraulic fluid; a fourth pump element provided within the fourth volume and operable to expand when actuated to pump hydraulic fluid from the fourth volume; a second accumulator in fluid communication with the third volume and the fourth volume; and a second power source electrically connected to the third pump element and the fourth pump element and operable to selectively supply power to the third pump element and the fourth pump element, wherein the second rolling bladder is in fluid communication with the third volume and the fourth volume, expands to an expanded state when hydraulic fluid flows into the second rolling bladder, contracts when hydraulic fluid flows out of the second rolling bladder, the third pump element expands when power is supplied to the third pump element to increase the pressure within the third volume and pump hydraulic fluid from the third volume to the second rolling bladder so that the second rolling bladder expands to an extended state, the fourth pump element expands when power is supplied to the fourth pump element to increase the pressure within the fourth volume and pump hydraulic fluid from the fourth volume to the second accumulator, and when power is removed from the fourth pump element, contracts so that fluid is discharged from the second rolling bladder to the fourth volume and the second rolling bladder contracts to a contracted state; including.;

Brief Description of the Drawings

[0033] The above and related objects, features, and advantages of the present disclosure will be more fully understood by reference to the following detailed description of the exemplary but preferred embodiments of the invention in conjunction with the accompanying drawings.

[0034]

Figure 1

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Figure 2

[0036]

Figure 3

[0037]

Figure 4A

[0038]

Figure 4B

[0039]

Figure 4C

[0040]

Figure 5A

[0041]

Figure 5B

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Figure 6

[0043]

Figure 7A

[0044]

Figure 7B

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Figure 7C

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Figure 7D

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Figure 8

[0048]

Figure 9

[0049]

Figure 10

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Figure 11

[0051]

Figure 12

[0052] FIG. 1 shows an exemplary block diagram of a spinal alignment system 100 that may include a pump mechanism 12 connected to a rolling bladder 14. In an embodiment, the pump mechanism 12 may include a pair of thermally actuated pumps (cartridges) 10a, 10b that function to pump fluid from the accumulator 16 to the rolling bladder 14, or from the rolling bladder to the accumulator 16. In an embodiment, the accumulator 16 may be a zero-pressure reference fluid reservoir that stores the working fluid for the system 100. In such an embodiment, the accumulator 16 may be connected to the pump mechanism 12 by a catheter and implanted with the fluid pump but not integral with the fluid pump. In an embodiment, the accumulator 16 may be, or may include, an inflatable bag made of polyvinyl chloride (PVC) similar to that of an externally used IV bag. In an embodiment, this inflatable bag may be composed of a selectively permeable membrane that allows the body water, which can be used as the working fluid, to replenish the fluid supply within the accumulator 16. In an embodiment, the rolling bladder 14 may be a type of hydraulic element that provides an expansion force and accompanying expansion when pressurized by the working fluid, depending on the design requirements.

[0053] In an embodiment, the power to the pump mechanism 12, specifically the thermally actuated pumps 10a, 10b, may be supplied by a power source 18. In an embodiment, the power source 18 may be an inductive coupling coil as can be seen, for example, in FIG. 1. In an embodiment, the power source 18 may be a multi-turn induction coil and may be disposed beneath the patient's skin within the patient's body. In an embodiment, the plane of the coil is substantially parallel to the surface of the patient's skin to facilitate efficient coupling with the external primary coil 20. In an embodiment, the power source 18 may be an on-board power source such as a battery, for example. In an embodiment, the power source 18 (coil) may be part of a near-field charging system that does not require a physical connection to the outside of the patient to supply power. In an embodiment, the external primary coil 20 may be energized by a rectified sine wave current of positive or negative polarity. In an embodiment, the rectified sine wave current may be used to induce in the secondary coil 18 a current that can be conducted through the diodes D1, D2 to the heating elements 116a or 116b of the two thermally actuated pumps 10a, 10b. In an embodiment, other suitable power circuits may be used in place of the diodes D1, D2 to selectively supply power to the first pump 10a and the second pump 10b to operate the first pump 10a and the second pump 10b. In an embodiment, the power circuit may include a processor or other control circuit. In an embodiment, the power circuit may be used, for example, to manage power consumption when the power source 18 includes a battery, for example.

[0054] In an embodiment, to control the inflation of the rolling bladder 14, the pulsed current of the positive rectified sine wave signal in the primary coil 20 induces a secondary current in the coil 18, and this secondary current is supplied to a thermo - operating pump 10a disposed in a volume V1 filled with a working fluid, thereby expanding the thermo - operating pump 10a to increase the pressure within the volume V1, and while back - stopping the valve CV1a, passing the stored working fluid through the check valve CV1b. In an embodiment, as can be seen in FIG. 4B, the working fluid may flow into the rolling bladder 14, thereby expanding the rolling bladder 14 to an inflated state. In an embodiment, pressure is transmitted to the volume V2 via the check valve CV2b, but the raised nature of the thermo - operating pump 10b within the volume V2 and the pressure relief valve RV2 prevent the fluid from returning to the accumulator 16. When the thermo - operating pump 10a is de - energized, the thermo - operating pump 10a contracts, and due to the reduced pressure, the working fluid is drawn from the accumulator 16 through the check valve CV1a, while the back - stopping state of CV1b holds the pressure within the rolling bladder 14, thereby maintaining the extended position of the bladder 14.

[0055] In an embodiment, as shown in FIG. 4A, in order to contract the rolling bladder 14 to a contracted state, for example, by supplying a rectified sine wave signal of opposite polarity, for example, the pulse current in the primary coil 20 may be reversed, whereby the secondary current is transmitted via the coil 18 to the heat-operated pump 10b in the volume V2. As the heat-operated pump 10b in V2 expands, the check valve CV2b is backstopped (closed), and the pressure in the volume V2 rises until the relief valve RV2 relieves the pressure to send fluid from the volume V2 to the accumulator 16. When the current is removed, the heat-operated pump 10b contracts, the pressure in the volume V2 decreases, whereby the relief valve RV2 closes. Further contraction of the heat-operated pump 10b in the volume V2 causes the pressure in V2 to further decrease until the check valve CV2b opens to allow fluid to flow back into the volume V2 from the rolling bladder 14. Removal of the working fluid from the rolling bladder 14 reduces the pressure therein, and as a result, the bladder 14 contracts to a contracted state. In an embodiment, the heat-operated pumps 10a, 10b may include respective bellows structures 112a, 112b (see, for example, FIG. 1) that hold a thermoresponsive material such as eutectic wax, and respective heating elements 116a, 116b that, when actuated, heat the wax to melt and expand it to expand the bellows structures 116a, 116b. When the heating elements 116a, 116b are deactivated, the wax cools and solidifies, and contracts, causing the bellows structures 112a, 112b to contract. In an embodiment, the bellows structures 112a, 112b may be biased to a contracted position. In an embodiment, the first heat-operated pump 10a and the second heat-operated pump 10b may be embodied by a heat-operated actuator component described in the co-pending U.S. non-provisional patent application Ser. No. 17 / 176,732, filed Feb. 16, 2021, entitled "BIDIRECTIONAL THERMALLY ACTUATED COMPONENT FOR USE IN MEDICAL DEVICES" by the present applicant, the entire content of which is incorporated herein by reference.In an embodiment, the power source 18 may be electrically connected to each of the expandable bellows structures 112a, 112b and respective heating elements 116a, 116b used to apply heat to the eutectic wax contained therein.

[0056] In an embodiment, the rolling bladder 14 may be used to apply a force to one or more vertebrae in a user's spine. In an embodiment, the rolling bladder 14 may be controlled to expand and contract as desired to provide pressure to facilitate alignment of the vertebrae. In an embodiment, a plurality of bladders 14 may be used to apply pressure to a plurality of vertebrae, as can be seen, for example, in FIGS. 2-3. In an embodiment, the bladders 14 may be individually controlled to apply different amounts of pressure to different vertebrae. In an embodiment, the fastener 50 may be fixed to the vertebrae, and the rolling bladder 14 may be disposed between the fasteners. In an embodiment, the fastener 50 may be, for example, a pedicle screw, as shown in FIG. 5B. In an embodiment, each respective pump mechanism 12 may be connected via an element 40 and used to control the expansion and contraction of each respective rolling bladder 14 to adjust the spacing between the vertebrae to which the fastener 50 is attached. In an embodiment, each of the respective pump mechanisms 12 may be separately controlled such that each rolling bladder 14 can be individually controlled to provide a desired spacing between a particular pair of vertebrae. In an embodiment, each of the respective pump mechanisms 12 may be separately controlled by separately controlling the power to each of the respective pumps 12.

[0057] In an embodiment, each rolling bladder 14 may be controlled together. In an embodiment, a single pump 12 may be provided to be in fluid communication with each of the rolling bladders 14. In an embodiment, a single pump mechanism 12 may be provided within a housing 110, for example, as shown in FIG. 6. In an embodiment, a single pump mechanism 12 may be operable to supply a working fluid to each of the rolling bladders 14 shown in FIGS. 2-3, for example. In an embodiment, the fastener 50 may include, for example, a fluid connector (article 40a) to enable the flow of the working fluid from the pump mechanism 12 to the plurality of rolling bladders 14 in FIG. 3. In an embodiment, an end connector 40b may be provided at an end of the system 100.

[0058] FIG. 4A shows an exemplary embodiment of the rolling bladder 14 in a contracted state or a contracted position. FIG. 4B shows an exemplary embodiment of the rolling bladder 14 in an extended state or an extended position. FIG. 4C shows a cross-sectional view of the rolling bladder 14 in a partially extended position. In an embodiment, the rolling bladder 14 may include a flexible wall and may be biased to the contracted position shown in FIG. 4A. In an embodiment, as the working fluid flows into the rolling bladder 14, the pressure within the rolling bladder 14 increases, causing the flexible wall to expand to an extended state. When the working fluid is discharged from the rolling bladder 14, the pressure within the bladder decreases, and the flexible wall contracts to a contracted state.

[0059] FIG. 5A shows an example of a spinal alignment system 100 including a plurality of rolling bladders 14 connected to each other in an extended position. FIG. 5B shows an example of a spinal alignment system 100 including a plurality of rolling bladders 14 connected to each other in a contracted position. In an embodiment, the rolling bladders 14 are connected via a connection element 40. In an embodiment, the connection element 40 includes a fluid conduit 40a extending through the connection element 40 that provides fluid communication between the rolling bladders 14 such that each rolling bladder expands and contracts together. In an embodiment, the connection element 40 may be or include a fastener 50 connected to a vertebra, and the rolling bladders 14 may be provided therebetween. In an embodiment, the spinal alignment system 100 may include a pump connector 60 provided at one end of the system 100 and configured to provide a fluid connection between the pump 12 and the rolling bladders 14 described above to supply and discharge the working fluid to and from the rolling bladders. In an embodiment, the pump connector 60 may include a working fluid inlet 60a in fluid communication with the pump mechanism 12 and the rolling bladders 14. In an embodiment, the rolling bladders 14 may be connected to individual pump mechanisms 12, in which case the passage 40a of the connection element 40 is in an elbow shape and may be connected to each pump mechanism.

[0060] FIG. 6 shows an exemplary schematic view of a pump mechanism 12 provided within a housing 110 for use in the system 100 of FIGS. 1-3 and 5A. In an embodiment, the volumes V1 and V2 may be integrated as separate compartments within the housing 110. In an embodiment, the pump 10a including the bellows 112a may be provided within the volume V1, and the pump 10b including the bellows 112b may be provided within the volume V2. In an embodiment, the accumulator 16 may be provided outside the housing 110 and may be connected to the pumps 10a, 10b, for example, via a catheter as described above. FIG. 7A shows a side view of the pump mechanism 12 provided within the housing shown in FIG. 6, along with the cut line A-A, with details shown in FIG. 8. FIG. 7B shows an end view thereof, and FIG. 7C shows an end view of the opposite side, along with the cut line B-B, with details shown in FIG. 9. FIG. 7D shows the cut line C-C, with details shown in FIG. 10.

[0061] FIG. 8 shows an exemplary cross-sectional view of the pump mechanism 12 of FIG. 7A along the line A-A. FIG. 8 shows a tube stub or connector 12a that provides fluid communication with an accumulator 16 disposed outside the housing 110 such that a working fluid can flow between the pump mechanism and the accumulator. The tube stub or connector 12b provides fluid communication with the rolling bladder 14 such that fluid can flow between the pump mechanism and the rolling bladder 14. FIG. 8 also shows cross-sections of a first pump 10a and a second pump 10b, which may be thermal wax expansion elements, disposed within the volumes V1 and V2. The relief valve RV2 of FIG. 8 is shown in detail in FIG. 11.

[0062] FIG. 9 shows a cross-sectional view of the pump mechanism 12 of FIG. 7C along the line B-B. FIG. 9 also shows exemplary arrangements of each of the check valves CV1a, CV1b, and CV2b, which are shown in detail in FIG. 12.

[0063] FIG. 10 shows a cross-sectional view of the pump mechanism 12 of FIG. 7D along the line C-C, showing exemplary fluid passage connections between V1, RV2, and V2, CV2b, and RV2, and their connections to the accumulator 16.

[0064] FIG. 11 shows a cross-sectional view of the relief valve RV2. In an embodiment, as shown, the relief valve RV2 may be a direct-acting spring-loaded poppet-type relief valve. In an embodiment, the relief valve RV2 may include a housing 120, a valve seat 124, a guide 121 and / or a poppet 122 guided within the valve seat 124 and preloaded by a spring 123. The preload of the spring 123 acting on the poppet 122 presses the poppet 122 against the valve seat 124 to effect a seal against the fluid pressure in the volume V1 and the rolling bladder 14. When the pressure of V1, 14 acting in the region of the valve seat diameter generates a force greater than the force of the spring 123, the relief valve RV2 opens, allowing fluid to flow from V1, 14 to the accumulator 16. The desired pressure threshold depends on the desired force in the rolling bladder 14 and its cross-sectional area and on the patient's particulars. Based on the desired packing and performance parameters, other relief valve configurations may be used as appropriate.

[0065] FIG. 12 shows cross-sectional views of exemplary check valves CV1a, CV1b, CV2b. Similar to the relief valve RV2, the check valves in FIG. 12 are shown as direct-acting spring-loaded poppet-type check valves. In an embodiment, each check valve may include a housing 130, a valve seat 131, and a poppet 132 guided within the valve seat 131 and preloaded by a spring 133. An end cap 134 may be included to facilitate assembly within the housing. In an embodiment, the check valves CV1a, CV1b, CV2b are biased to close the poppet 132 using a small spring force. The pressure acting in the check direction opposite to the flow direction further increases the force acting to close the check valve, preventing flow in the check direction. These check valves CV1a, CV1b, CV2b act to control the flow of the working fluid as described with reference to FIG. 1.

[0066] In an embodiment, the power source 18 may be mounted under the user's skin and the primary coil 20 may be provided externally to induce a current in the pump mechanism 12.

[0067] Although the embodiments of the present invention have been shown and described in detail up to this point, various modifications and improvements may readily become apparent to those skilled in the art. Therefore, the exemplary embodiments of the present invention described above are intended to be illustrative rather than limiting. The spirit and scope of the present invention should be construed in a broad sense.

Claims

1. a rolling bladder configured to expand from a deflated state to an inflated state and from said inflated state back to said deflated state; a pump connected to the rolling bladder and configured to supply hydraulic fluid to the rolling bladder so that the rolling bladder expands to the expanded state and to remove hydraulic fluid from the rolling bladder so that the rolling bladder contracts to the contracted state; a first volume filled with the hydraulic fluid and operatively connected to the pump; a second volume filled with the hydraulic fluid and operatively connected to the pump; an accumulator in fluid communication with the first volume and the second volume; a power source electrically connected to the pump and operable to selectively power the pump; Including, the pump pumps the hydraulic fluid from the first volume to the rolling bladder such that the rolling bladder expands to the expanded state; and selectively operable to pump hydraulic fluid from the second volume to the accumulator such that fluid is discharged from the rolling bladder to the second volume causing the rolling bladder to contract to the contracted state. Spinal adjustment system.

2. a first check valve disposed between the first volume and the rolling bladder and configured to control a flow of hydraulic fluid from the first volume to the rolling bladder; a second check valve disposed between the first volume and the accumulator and configured to control a flow of hydraulic fluid between the first volume and the accumulator; a third check valve disposed between the second volume and the rolling bladder and configured to control a flow of hydraulic fluid from the rolling bladder to the second volume; a relief valve between the second volume and the accumulator and configured to control a flow of hydraulic fluid from the second volume to the accumulator; 10. The spinal adjustment system of claim 1, further comprising:

3. 3. The spinal adjustment system of claim 2, wherein the first check valve allows hydraulic fluid to flow from the first volume to the rolling bladder and prevents hydraulic fluid from flowing back from the rolling bladder to the first volume.

4. 3. The spinal adjustment system of claim 2, wherein the second check valve allows hydraulic fluid to flow from the accumulator to the first volume.

5. 3. The spinal adjustment system of claim 2, wherein the relief valve is configured to allow hydraulic fluid to flow from the second volume to the accumulator.

6. 3. The spinal adjustment system of claim 2, wherein the third check valve is configured to allow the hydraulic fluid to flow from the rolling bladder to the second volume such that the rolling bladder returns to the contracted state.

7. The spinal adjustment system of claim 1 , wherein the power source is a wire coil.

8. 8. The spinal adjustment system of claim 7, further comprising a power supply circuit configured to selectively power the pump.

9. 8. The spinal adjustment system of claim 7, wherein the wire coil is paired with the external wire coil such that a current is induced in the wire coil when the external wire coil is placed adjacent to the wire coil.

10. 10. The spinal adjustment system of claim 1, wherein the rolling bladder is positioned between the first vertebra and the second vertebra such that expansion of the rolling bladder changes a spacing between the first vertebra and the second vertebra.

11. a first rolling bladder configured to expand from a deflated state to an inflated state and from the inflated state to the deflated state; a second rolling bladder configured to expand from a deflated state to an inflated state and from the inflated state to the deflated state; a pump in fluid communication with the first rolling bladder and the second rolling bladder and configured to supply hydraulic fluid to the first rolling bladder and the second rolling bladder so that the first rolling bladder and the second rolling bladder, respectively, expand to the expanded state and remove hydraulic fluid from the first rolling bladder and the second rolling bladder so that the first rolling bladder and the second rolling bladder, respectively, contract to the contracted state; a first volume filled with the working fluid; and a second volume filled with the working fluid; and an accumulator in fluid communication with the first volume and the second volume; a power source electrically connected to the pump and operable to selectively power the pump; Including, the first rolling bladder and the second rolling bladder are in fluid communication with the first volume and the second volume, expand to the expanded state when the pump is actuated to provide hydraulic fluid to the first rolling bladder and the second rolling bladder, and contract when the hydraulic fluid exits the first rolling bladder and the second rolling bladder. Spinal adjustment system.

12. a first check valve disposed between the first volume and the first rolling bladder and the second rolling bladder and configured to control a flow of hydraulic fluid from the first volume to the first rolling bladder and the second rolling bladder; a second check valve disposed between the first volume and the accumulator and configured to control a flow of hydraulic fluid between the first volume and the accumulator; a third check valve disposed between the second volume and the first and second rolling bladders and configured to control a flow of hydraulic fluid from the first and second rolling bladders to the second volume; a relief valve between the second volume and the accumulator and configured to control a flow of hydraulic fluid from the second volume to the accumulator; 12. The spinal adjustment system of claim 11, further comprising:

13. 13. The spinal adjustment system of claim 12, wherein the first check valve allows hydraulic fluid to flow from the first volume to the first and second rolling bladders and prevents hydraulic fluid from flowing back from the first and second rolling bladders to the first volume.

14. 13. The spinal adjustment system of claim 12, wherein the second check valve allows hydraulic fluid to flow from the accumulator to the first volume.

15. 13. The spinal adjustment system of claim 12, wherein the relief valve is configured to allow hydraulic fluid to flow from the second volume to the accumulator.

16. 13. The spinal adjustment system of claim 12, wherein the third check valve is configured to allow the hydraulic fluid to flow from the first and second rolling bladders to the second volume such that the first and second rolling bladders return to the contracted state.

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