Pressure monitoring post used for anterior hip arthroplasty and arthroscopy

Abstract

The present invention provides an apparatus for sensing the pressure on the body of a patient on an anterior hip table or a standard surgical table. The pressure monitoring post provides a warning indicator when the pressure exceeds a predetermined value that is related to pressure related injuries. The pressure monitoring post may also provide for a center and two lateral pressure sensors to detect the pressure resulting on a patient's body during various processes related to hip distraction for arthroscopy and arthroplasty procedures.

Claims

1. An orthopedic surgical table, comprising: a table having a first end, a second end, and a support surface; a post disposed on the table and extending from the support surface near the second end; a post overlay configured to surround at least a portion of the post; a sensor configured to measure a pressure exerted against the post; and, wherein the post overlay further comprises a body bordered at least in part by a front wall, the body having a bore defined therein configured to receive the post, the front wall having a concave surface configured to provide space to accommodate a genital area of a patient to reduce the overall pressure into the post as it relates to genital tissue of the patient during hip distraction.

2. The table of claim 1, wherein the sensor is mounted on the post.

3. The table of claim 1, wherein the sensor is mounted between the post overlay and the post.

4. The table of claim 1, wherein the sensor is mounted on the outside of the post overlay.

5. The table of claim 1, further comprising a pair of laterally extending members supported from the post, the laterally extending members having pressure sensors disposed thereon.

6. The table of claim 5, wherein the laterally extending members are pivotally connected to the post.

7. The table of claim 6, wherein the laterally extending members are spring biased in an open angularly spaced apart relation.

8. The table of claim 1, wherein the first end of the table has a width greater than the second end of the table.

9. The table of claim 1, wherein the sensor is selected from the group consisting of electric, mechanical, and hydraulic sensors.

10. The table of claim 1, wherein the post overlay is round.

11. The table of claim 1, further comprising a warning indicator configured to provide an alert when the pressure measured by the sensor exceeds a predetermined value.

12. The table of claim 11, wherein the warning indicator provides an indication selected from the group of visual and audible.

13. The table of claim 11, wherein the warning indicator is configured to extend vertically relative to the top of the post.

14. The table of claim 1, further wherein the post overlay is configured to contact the inner thigh of the patient, the sensor comprises a center and two lateral pressure sensors disposed on the post overlay.

15. The table of claim 14, wherein the post overlay is comprised of soft membrane materials such as foam, fluid bladders, TPEs, silicones, or other compliant materials that allow for greater surface area interference with the anatomy of a patient.

16. An orthopedic surgical table, comprising: a table having a first end, a second end, and a support surface; a post disposed on the table and extending from the support surface near the second end; a post overlay configured to surround at least a portion of the post; a sensor configured to measure a pressure exerted against the post; further comprising a warning indicator configured to provide an alert when the pressure measured by the sensor exceeds a predetermined value; wherein the warning indicator is configured to extend vertically relative to the top of the post; and, wherein the warning indicator is spring biased in a normally closed position.

17. The table of claim 16, wherein the warning indicator is mechanically actuated by a linkage.

18. The table of claim 16, wherein the warning indicator is hydraulically actuated.

19. An orthopedic surgical table, comprising: a table having a first end, a second end, and a support surface; a post disposed on the table and extending from the support surface near the second end; a post overlay configured to surround at least a portion of the post; a sensor configured to measure a pressure exerted against the post; further comprising a warning indicator configured to provide an alert when the pressure measured by the sensor exceeds a predetermined value; and, wherein the post has a soft membrane configured such that, when pressure is applied to the membrane, an internal piston drives a small amount of fluid through a tube to activate the warning indicator.

20. An orthopedic surgical table, comprising: a table having a first end, a second end, and a support surface; a post disposed on the table and extending from the support surface near the second end; a post overlay configured to surround at least a portion of the post; a sensor configured to measure a pressure exerted against the post; further comprising a warning indicator configured to provide an alert when the pressure measured by the sensor exceeds a predetermined value; and, further comprising panels on the post where a direct linkage to the panels on the post can be depressed by the application of pressure in combination with a force limiting spring configured to drive the warning indicator to show the amount of pressure being applied to the post.

21. An orthopedic surgical table, comprising: a table having a first end, a second end, and a support surface; a post disposed on the table and extending from the support surface near the second end; a post overlay configured to surround at least a portion of the post; a sensor configured to measure a pressure exerted against the post; wherein the post overlay further comprises a body bordered at least in part by a front wall, and a pair of side walls, the body having a bore defined therein configured to receive the post; the side walls having a concave surface; and, the front wall having a concave surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of an orthopedic surgical table platform designed specifically for anterior hip surgical access.

(2) FIG. 2 is a perspective view of a pad assembly disposed on the upper surface of an orthopedic surgical table platform.

(3) FIG. 3 is a perspective view of a pad assembly and a post overlay on a standard surgical table.

(4) FIG. 4 is a top perspective view of a post overlay of the present invention.

(5) FIG. 5 is a perspective view of the post overlay of FIG. 4.

(6) FIG. 6 is a top perspective view of the post overlay of FIG. 4.

(7) FIG. 7 is a side elevational view of the post overlay of FIG. 4.

(8) FIG. 8 is a rear elevational view of the post overlay of FIG. 4.

(9) FIG. 9 is a perspective view of one embodiment of the pressure monitoring post and post overlay of the present invention.

(10) FIG. 10 is an exploded perspective view of the apparatus shown in FIG. 9.

(11) FIG. 11 is a cutaway elevational view of one embodiment of the sensor.

(12) FIG. 12 is a cutaway elevational view of another embodiment of the sensor.

(13) FIG. 13 is a cutaway elevational view of another embodiment of the sensor.

(14) FIG. 14 is a cutaway elevational view of another embodiment of the sensor.

(15) FIG. 15 is a perspective view of an alternate embodiment that includes a center and two lateral sensors.

(16) FIG. 16 is a perspective view of a saddle shaped post overlay containing a center and two lateral sensors.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(17) At the outset, it should be clearly understood that like reference numerals are intended to identify the same structural elements, portions or surfaces consistently throughout the several drawing figures, as such elements, portions or surfaces may be further described or explained by the entire written specification, of which this detailed description is an integral part. Unless otherwise indicated, the drawings are intended to be read (e.g., cross-hatching, arrangement of parts, proportion, debris, etc.) together with the specification, and are to be considered a portion of the entire written description of this invention. As used in the following description, the terms horizontal, vertical, left, right, up and down, as well as adjectival and adverbial derivatives thereof, (e.g., horizontally, rightwardly, upwardly, etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms inwardly and outwardly generally refer to the orientation of a surface relative to its axis of elongation, or of rotation, as appropriate.

(18) Referring to FIGS. 1-8 generally, and initially to FIG. 1, an orthopedic surgical table platform 30 such as the HANA brand table available from Mizuho OSI of Union City, California, has a first end 33 and a second end 36 disposed opposite from the first end 33. The platform 30 is wider at the first end 33 and gradually narrows inward from opposed sides 39, 42 until it reaches the second end 36. A cylindrical post 45 may be disposed in spaced apart relation from the second end 36. The post 45 may extend for a relatively short distance above a top surface 48 of the surgical table platform. The top surface 48 may be planar as shown. In use, a patient may be supported on the top surface 48 such that the torso extends downward and each leg of the patient may be disposed on opposite sides of the post 45. The legs of the patient may extend to foot support 51 that may be supported by elongate members 57 and 60 extending from the base 63. A foot support 51 may be adjustably mounted on both elongate members 57, 60 as shown in connection with member 60 in the drawing. The base 63 supports the elongate members 57 and 60 and provides for adjustment of the elongate members 57, 60 in multiple planes. The base 63 also supports the platform 30 and top surface 48. The base 63 may also be provided with casters 66.

(19) Turning to FIG. 2, a pad assembly 69 of the present invention may be supported on the top surface 48. The pad assembly 69 has a foam top 72 with a planar surface 75 that supports a patient undergoing a procedure on the platform 30. As shown the foam top 72 has a shape that conforms to the shape of the top surface 48 with a bottom portion 78, opposed side portions 81, 84, and a top portion 87. The top portion 87 is formed by two inward angled sections 90 and 93 that provide for a truncated top portion 87 that provides room for the post 45 (FIG. 1). The pad assembly 69 is described in greater detail herein.

(20) In FIG. 3, an alternate embodiment of the pad assembly 69 is shown. Pad assembly 100 may be mounted on a standard rectangular shaped surgical table 103. A standard bed rail 106 extends from the side of the table 103. A post 45 and post overlay 106 are shown at one end of the table 103. The components of the pad assembly 100 and post overlay 106 are described in greater detail herein.

(21) Turning to FIG. 4, the post overlay 106 may be constructed of a resilient, flexible material that provides cushioning to prevent injuries when the body of the patient contacts the post 45 during a medical procedure. The foam may comprise a polyurethane foam having 1.8-6 lb density with a 24-45 ILD (indentation load deflection) range. Other flexible foam materials may also be suitable. The post overlay 106 has a front wall 109, a rear wall 112, and opposed side walls 115, 118. The post overlay 106 has a central body portion 121 with an opening 124 defined therein. The opening 124 has an inside diameter sized to mate with the outside diameter of the post 45. Other shapes for the opening 124 and the post 45 may also be suitable as will be evident to those of ordinary skill in the art based on this disclosure.

(22) In FIG. 5, the side wall 118 is concave. The side wall 115 on the side opposite from side wall 118 is also concave. The front wall 109 is also concave. The front wall 109 is widest as the top 140 and the bottom 143 and is narrower in a mid-portion 146. Accordingly, the front wall 109 has an hourglass shape with inward curves at the top and bottom and in the middle.

(23) Turning to FIG. 6, the rear wall 112 may be substantially flat and is straight at the top edge 150 and bottom edge 153. The sides 156, 159 of the rear wall 112 are curved inward. The opening 124 for the post 45 extends from the top surface through the entire height of the post overlay 106. The front wall 109 is concave.

(24) In FIG. 7, the side wall 118 is shown in greater detail. At the bottom edge 127, the side wall 118 has a length L1 that is greater than the length L2 of the top edge 130. The rear 133 of the side wall 118 is substantially vertical and is oriented at approximately ninety degrees with respect to the top and bottom edges 130, 127 of the side wall 118. The front of the side wall 118 curves from the bottom edge 127 to the top edge 130.

(25) In FIG. 8, the rear wall 112 is best shown. The side walls 115, 118 curve inward from the top edges to the bottom edges along an arc.

(26) The design of the post overlay 106 provides space to accommodate the genital area thereby reducing the overall pressure into the post 45 as it relates to genital tissue. The lateral concave surfaces of the side walls 115, 118 accommodate the legs when adducted, or during any crossover movements required to help with joint distraction. The ILD and makeup of the foam pad 72 provides the necessary force deflection to minimize tissue pressure while absorbing inertial forces into foam instead of the post 45 in contrast to typical round overlays. When combined with the underlying movable friction foam pad option, the overall inertia into the post 45 is greatly reduced over standard reliance on either post overlay or foam pad alone.

(27) Turning to FIGS. 9-21 generally and initially to FIGS. 9-10, a sensor 200 may be disposed between the post 45 and the post overlay 106. As described above, the post overlay 106 has a shape designed to reduce the possibility of injury to the genital area of a patient straddling the post 45. The sensor 200 may be provided with a warning indicator 203 that may extend upward along the outside of the post 45. The warning indicator 203 may be actuated when the sensor 200 reads a pressure that exceeds a predetermined level. As discussed above there are specific levels above which pressure related injuries may occur (i.e., 32 mm Hg or 0.621 psi).

(28) Turning to FIGS. 11-14, and initially to FIG. 11, in one embodiment the sensor 200 may comprise a membrane 210. When pressure is applied to the membrane 213, a piston 216 drives a small amount of fluid into a chamber 217 with a spring 219 biased warning indicator 222.

(29) In FIG. 12, a bladder 230 may hold a fluid. When pressure is applied to the outside surface of the bladder 230, the fluid passes through tube 233 and provides a force against spring 236. The upward force against the spring 236 causes the warning indicator 239 to elevate providing a visual indication that the pressure of the patient on the post 45 has exceeded a predetermined value.

(30) In FIG. 13 a mechanical linkage provides for actuating a warning indicator 250. When pressure above a certain predetermined level is exerted against surface 253, the pressure overcomes the force of a spring 256 to cause a linkage to transmit a force sufficient to move the warning indicator 250 from a spring biased normally closed position to an open position. The first link 259 is connected to a second link 262 and is configured to cause one of the ends of the second link 262 to move upward against the force of a spring 265. The first and second links 259, 262 are connected by a pin 268 that is captured by and travels in a slot 271. When the pressure acting on surface 253 exceeds a predetermined level, the linkage overcomes the force of springs 256 and 265 to actuate the warning indicator 250.

(31) FIG. 14 discloses a hydraulically actuated warning indicator 280. When pressure acts on surface 283 a plunger pushes a fluid through a tube 286. The opposite end of the tube 286 is in fluid communication with a plunger surface 287. The plunger 289 is spring 291 biased in the downward direction. The fluid presses against the plunger 289 to overcome the force of spring 291 to actuate the warning indicator 280.

(32) Turning to FIG. 15, an alternate embodiment of the sensor assembly of the present invention provides a center 300 and two lateral pressure sensors 303 and 306 for measuring pressures secondary to the inertial pressures due to single leg traction of right vs left. This configuration allows for relative pressure safety monitoring from applied hip distraction force and/or the relative pressure applied to the patient by the post when the patient is experiencing lateral forces due to gravity, contact with surgical team members, etc.

(33) The central pressure sensor 300 may be disposed on or around the post 45. The lateral pressure sensors 303 and 306 may be pivotally attached to the post 45 by a pair of arms 309 and 312. The arms 309 may comprise elongate link shaped members pivotally connected to rotate in opposite directions about the post 45. The arms 309 and 312 may support a pair of elongate curved members 315, 318 having outer surfaces 321, 324 ergonomically designed to engage with the inner thighs of the patient.

(34) Turning to FIG. 21, in an alternate embodiment, the center and lateral pressure sensors are contained within a saddle shaped enclosure 400. The center pressure sensor measure pressure against the front surface 403 of the enclosure 400, and the lateral pressure sensors measure the pressure against the angled outer surfaces 406 and 409.

(35) The present invention provides a modular friction pad assembly that may be paired with an optional post overlay designed to restrict movement incrementally from pad to skin surface of the lower buttocks, while accommodating genital anatomic structures via a concave and non-rounded design that is gradually accentuated from top to bottom. This post overlay design reduces the overall force and inertia into the underlying post and accounts for genital, vascular, and nerve anatomy, and the special physics involved during hip joint distraction via manual or mechanical pulling of the legs.

(36) The present invention provides an optional post overlay design that is concave and slanted from top down towards patient's perineum needed to restrict mechanical and tissue force into the genitals, underlying nerves, and surrounding tissue.

(37) The present invention provides an optional post overlay with lateral concave design needed to support the legs during crossover distraction methods, thereby minimizing force into the underlying post from a lateral perspective against the thighs. The foam is a polyurethane foam of 1.8 lb-6 lb density with 24-45 ILD range. The post overlay may be paired with a modular friction pad assembly.

(38) The present invention provides an optional post overlay that when combined with a modular foam friction pad assembly, reduces the overall forces into a perineal post by more than either the overlay or pad assembly alone, especially when using distraction pressures higher than 150 lbs. of force, or when pulling lower extremities (distraction) on thin adults that may have more contralateral movements during distraction due to their weight and center of gravity changes. The combined lateral stability of the pad assembly and overlay may also reduce falls in high BMI patients on narrow angled hip tables in comparison to either product alone.

(39) The pad assembly of the present invention provides some friction resistance needed to disarticulate the joint and to reduce the amount of straddling pressure into a round post. If the post is still required to be used, the resistance decreases the amount of bodily inertia against the post, as the rest of the body's skin to friction contact on the underlying material holds traction and resists distal movement, thus minimizing perineal force movement into the post as the feet and legs are pulled.

(40) The present invention may provide a hybrid approach to include a post. As it may be unclear how much force is required for disarticulation, and the fact that there is no standard agreed or accepted amount of force in the industry, the post may serve as a minimal fulcrum force for distraction, or more importantly lateral stabilization.

(41) Therefore, while the presently-preferred form of the pressure monitoring post has been shown and described, and several modifications and alternatives discussed, persons skilled in this art will readily appreciate that various additional changes and modifications may be made without departing from the spirit of the invention, as defined and differentiated by the following claims.