Patient fixation system for the surgical Trendelenburg position

Abstract

The patient fixation overlay includes a cloth sheet configured to support the patient's torso on the operating table. The cloth sheet includes friction enhancing elements applied to at least a portion of the upper surface. The cloth sheet is attached to two or more side flaps that extend laterally outward from the side edges of the cloth sheet near the side edges of the cloth sheet. Each of the side flaps is attached to the operating table at two or more attachment points. The distance between adjacent attachment points is greater than the distance between the attachment points and the cloth sheet to naturally create a preferred holding force vector angle of less than 45°.

Description

Technical Field

[0001] (Related Application) This application is a continuation of U.S. patent application Ser. No. 17 / 896,456, filed Aug. 26, 2022, which claims priority to U.S. Provisional Patent Application No. 63 / 354,778, filed Jun. 23, 2022.

[0002] The present disclosure generally relates to patient fixation devices for stabilizing a patient on an operating table for the Trendelenburg position and other positions.

Background Art

[0003] When an operating table is tilted into a steep head-down (Trendelenburg) position, preventing a patient from sliding off the table is always a challenge for the surgical staff and dangerous for the patient. This problem has worsened in recent years with the advent of laparoscopic surgery, particularly robotic surgery. In any of these examples, the patient is regularly placed in a steep Trendelenburg position, which allows the weight to move the internal organs so as not to obstruct the laparoscope. Depending on the angle or steepness of the head-down Trendelenburg position, the patient's weight, and the structure of the support surface (e.g., the bed sheet), there is a risk that the patient will slide off the head end of the Trendelenburg-position operating table. This is particularly true for pelvic surgeries (e.g., rectal, gynecological, and urological), where the head of the operating table may be tilted as much as 45° downward to use gravity to move the bowel and other internal organs away from the pelvis and improve visibility of the surgical site.

[0004] Various patient fixation devices have been tried over the years. Generally, there are several categories of fixation devices, including straps and tapes, shoulder bolsters, foam operating table overlays, bean bags that are molded around the patient, and gel pads that adhere to the patient. Chest-wide straps and tapes have proven to be unsafe. Straps over the shoulders have caused stretch injuries to the nerves of the brachial plexus. Similarly, bolsters of foam or bean bags at the patient's shoulder fixed to the side rails of the bed have also resulted in stretch injuries to the nerves of the brachial plexus and are not recommended by the Association for Operating Room Nurses. Gel pads are cold and cumbersome because they adhere to everything.

[0005] Foam operating table overlays are a standard fixation device. The foam is generally sized to cover the portion of the operating table that supports the patient's torso and head. Regardless of the coefficient of friction of the foam against the patient's skin, the smooth surface of the surgical mattress usually creates a coefficient of friction between the foam and the mattress that is lower than the coefficient of friction between the foam and the patient. Therefore, unwanted slippage is most likely to occur between the mattress and the foam operating table overlay. To improve the connection between the mattress and the foam operating table overlay, the foam overlay is usually taped or strapped to the side rails of the operating table. However, for example, tapes attached to the foam operating table or straps adhered to the foam operating table overlay, as described in U.S. Patent No. 8,464,720 by Pigazzi, have a significantly high risk of becoming unbonded when a 400-pound patient's weight is applied at a 45° head-down angle. The adhesive may not work, or the top layer of the foam is peeled off from the foam operating table overlay while remaining adhered to the tape.

[0006] For example, as described in U.S. Patent No. 10,045,902, it has been proposed to use a thicker foam pad, such as a viscoelastic pad having a thickness of 3 / 4 of an inch to 3 inches or more, to form a depression having a depth sufficient to assist in holding the patient on the pad. In the present disclosure, the formation of a depression having a depth sufficient to assist in holding the patient on the pad is referred to as the "bolster effect". A disadvantage of any fixation device that depends wholly or in part on the bolster effect is that bolster-type fixation can be rendered ineffective by the excessive weight and rounded-shouldered shape often seen in obesity. Thus, a fixation device that depends in part on the bolster effect needs to provide instructions for use that limit both the patient's weight and the angle of descent.

SUMMARY OF THE INVENTION

[0007] It would be desirable to provide a highly reliable, safe, and convenient patient fixation device for stabilizing a patient on an operating table for Trendelenburg and other non-standard positions.

[0008] The present disclosure's underbody support mattresses and blankets are generally intended for use in a medical setting. These include operating rooms, emergency treatment rooms, intensive care units, hospital rooms, nursing facilities, and other treatment locations.

[0009] Various embodiments include a flexible and conformable heated underbody support, including mattresses, mattress overlays, and pads, that provide therapeutic warming to a person such as a patient in an operating room setting. In various embodiments, the heated underbody support is maximally flexible and conformable, such that the heated surface can deform and adapt to the person without reducing the underlying mattress's ability to adapt.

[0010] In some embodiments, a sheet of cloth or other material, at least partially coated on both sides with a friction enhancing element such as high friction plastic or rubber, can be interposed between the patient and the underbody support to increase the coefficient of friction therebetween. Examples of such friction enhancing elements can be PVC foam or silicone rubber applied as a pattern of three-dimensional raised dots on a sheet of cloth. Another example of such a friction enhancing element can be a foam layer attached to a cloth layer.

[0011] In some embodiments, a sheet of cloth that is at least partially coated or laminated with a friction enhancing element is secured to the side rail of the operating table by a cloth or film or cloth-reinforced film side fixing flap. The side fixing flap can be secured to the side rail by buttons, or hooks, or straps attached to a side rail adapter. Regardless of the attachment mechanism, the side fixing flap material is continuous between at least two adjacent attachment points to minimize the downward movement or stretching of the legs that naturally occurs during the Trendelenburg position or during extension (traction) of the legs during orthopedic hip surgery.

Brief Description of the Drawings

[0012]

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Mode for Carrying Out the Invention

[0013] The following detailed description is merely exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following description provides practical illustrations for implementing various exemplary embodiments. Examples of configurations, materials, dimensions, and manufacturing processes are provided for selected elements, and all other elements are those known to those skilled in the art. Those skilled in the art will recognize that many of the provided examples have suitable alternatives that can be utilized.

[0014] Each of the following U.S. patents is hereby incorporated by reference in its entirety: U.S. Patent No. 10,765,580, U.S. Patent No. 10,575,784, U.S. Patent No. 10,959,675, U.S. Patent No. 10,980,694, U.S. Patent No. 10,993,866, U.S. Patent No. 11,103,188, and U.S. Patent No. 11,278,463.

[0015] In some embodiments, as shown in FIG. 1, the embodiment includes an underbody support, such as an underbody support including a mattress, a mattress overlay, and a pad. The term underbody support can be considered to encompass any surface placed under a user who is generally in a lying position, such as a patient who may be undergoing surgery, to support the user, including a mattress, a mattress overlay, and a pad. In some examples, the underbody support can be heated.

[0016] Embodiments of the mattress overlay can be similar or identical to embodiments of the pad, the only difference being whether they are used on top of a mattress. Further, the difference between embodiments of the pad and embodiments of the mattress can be the amount of support and adaptation they provide, and some pads may be insufficiently supportive to be used alone like a mattress. Accordingly, the various aspects described herein apply to embodiments of mattresses, mattress overlays, and pads even when only one type of support is shown in a particular example.

[0017] Although this disclosure makes repeated reference to a "heated underbody support", one of ordinary skill in the art will understand that a heating function is not a necessary component of all embodiments. Embodiments of non-heated underbody supports are also contemplated.

[0018] In some embodiments, a heated underbody support includes a heater assembly and a layer of compressible material. The heater assembly can include a heating element that includes a sheet of conductive fabric having a top surface, a bottom surface, a first edge, an opposing second edge, a length, and a width. The conductive fabric can include yarns individually coated with a conductive or semiconductive material, and the coated yarns of the fabric can slide relative to each other such that the sheet is flexible and stretchable. In some embodiments, the conductive fabric can be made of conductive yarns such as carbon fibers. In some embodiments, the sheet is made of conductive ink applied to a polymer film such as a polyester film, and thus is not made of conductive fabric. In some embodiments, the heater is made of a conductive film such as a plastic film with carbon or graphite added.

[0019] The heater assembly can also include a first bus bar extending along the entire first edge of the heating element and adapted to receive a supply of power, a second bus bar extending along the entire second edge of the heating element, and a temperature sensor. The layer of compressible material can be adapted to conform to a person's body under pressure from a person sitting on the support and can be adapted to return to its original shape when the pressure is removed. It can be positioned under the heater assembly and can have a top surface and an opposing bottom surface, a length, and a width, and the length and width of the layer are substantially the same as the length and width of the heater assembly.

[0020] In some embodiments, the bus bar can be a braided wire. In some embodiments, it may be desirable to coat the bus bar with a flexible rubber material such as silicone rubber during the construction of the heater. Braided wires are relatively resistant to repeated bending, but even bus bars made of braided wires can break and be damaged if bent repeatedly in the same place. Coating the bus bar with silicone rubber significantly improves the durability of the bus bar and enables it to withstand repeated bending.

[0021] In some embodiments, the conductive or semiconductive material is polypyrrole. In some embodiments, the compressible material includes a foam material, and in some embodiments, it includes one or more air-filled cavities. In some embodiments, the heating underbody support also includes a water-resistant shell that encloses the heater assembly and can include an upper shell and a lower shell that are sealed together along their edges to form a joining edge, and the heater assembly is attached to the shell only along one or more edges of the heater assembly. In some embodiments, the heating element generally has a planar shape when no pressure is applied. The heating element is adapted to extend into a three-dimensional complex curve without wrinkling or creasing while maintaining conductivity in response to pressure and can return to the same generally planar shape when the pressure is removed.

[0022] In some embodiments, the heating underbody support includes a heater assembly that includes a flexible heating element comprising a sheet of conductive fabric having a top surface, a bottom surface, a first edge and an opposing second edge, a length, and a width, a first bus bar extending along the first edge of the heating element and adapted to receive a supply of power, a second bus bar extending along the second edge of the heating element, and a temperature sensor. The underbody support may further include a layer of compressible support material located under the heater assembly, which conforms to the patient's body under pressure and returns to its original shape when the pressure is removed.

[0023] In some such embodiments, the heating element includes a cloth coated with a conductive or semiconductive material, which may be a polymer or ink containing carbon or metal, or may be a polymer such as polypyrrole. In some embodiments, the heating underbody support also includes a shell comprising at least two flexible shell materials surrounding the heater assembly, the shell being a water-resistant plastic film or a fiber-reinforced plastic film in which at least two sheets near the edge of the heater assembly are sealed together. In some embodiments, the heating underbody support also includes a power supply and a controller for regulating the supply of power to the first bus bar.

[0024] In some such embodiments, the compressible material is a foam material. The heater assembly can be attached to the upper surface of the layer of compressible material. In some embodiments, the heating underbody support includes a water-resistant shell having an upper shell and a lower shell that enclose the heater assembly and are sealed together along their edges to form a joined edge. In some such embodiments, one or more edges of the heater assembly can be sealed inside the joined edge. In some embodiments, the heater assembly is attached to the shell only along one or more edges of the heater assembly. In some embodiments, the heater assembly is attached to a layer of compressible foam material. In some embodiments, the heating underbody support also includes an electrical inlet, the inlet being coupled to the upper shell and the lower shell and passing therebetween at the joined edge. In some embodiments, the heating underbody support also includes an electrical inlet, the inlet being joined to the sidewall of the shell.

[0025] In some embodiments, the temperature sensor is adapted to monitor the temperature of the heating element and is positioned in contact with the heating element at the location where the patient is placed during normal use of the support. In some embodiments, the heated underbody support also includes a power source and a controller for regulating the supply of power to the first bus bar. Some embodiments of the heating pad and mattress are disclosed in U.S. Patent No. 8,604,391, U.S. Patent No. 9,962,122, U.S. Patent No. 10,201,935, and U.S. Patent No. 10,206,248, the entire disclosures of which are incorporated herein by reference.

[0026] The steep Trendelenburg position is often used during urological, gynecological, and colorectal surgeries, especially in surgeries using a robot or laparoscope. As shown in Figure 2, the patient 2 is typically positioned supine on the operating table 4 with the legs flexed 6 high. In some cases, each flexure 6 is individually shown in the drawing as reference numerals 6A and 6B. The operating table 4 can optionally include metal. The foot end 8 of the operating table 4 is lowered to allow the surgeon or robot to access the patient's perineum. The steep Trendelenburg position pulls the abdominal contents away from the pelvis by gravity, allowing for unobstructed access and visualization with a laparoscope. The patient's buttocks are typically positioned at the foot end 10 of the underbody support or at the foot end 10 of the portion 12 of the operating table mattress 30 that supports the patient's torso. The foot end 10 of the underbody support 16 or portion 12 of the operating table mattress 30 that supports the patient's torso typically has a notch cut out from the center of the foot end, known as the perineal notch 14, as shown in Figure 3. The perineal notch 14 allows the patient's perineum to hang slightly over the center edge of the operating table mattress 30 while providing support to the sides of the buttocks when the legs are raised. The perineal notch helps the surgeon or robot access the patient's perineum without obstruction.

[0027] The underbody support 16 may include elements for securing the underbody support 16 to the operating table 4. In some embodiments, the securing elements may be Velcro® fasteners between the upper surface of the operating table 4 and the lower surface of the underbody support 16. The lower surface may also be referred to as the table interface surface.

[0028] In some embodiments, the securing elements for the underbody support 16 may be strap fasteners between the side surface of the operating table 4 and the durable shell of the underbody support 16. As shown in FIG. 4, the strap 18 of the strap fastener may be made of a non-stretchable reinforced strap material that can be wrapped around the side rail 20 of the operating table 4 and then secured to itself. In some cases, the strap 18 is individually shown in the drawing as reference numerals 18A and 18B. The straps 18A, 18B can be secured with buttons, snaps, hooks, barbs, Velcro®, or other suitable secure attachments. In some embodiments, the straps 18A and 18B may be attached to the underbody support 16 by one or more strap attachment protrusions 22 of the upper and lower shell material layers from the side surface of the underbody support 16. The one or more strap attachment protrusions 22 may be part of the circumferential weld between the upper and lower shell material layers of the underbody support 16 discussed previously. The one or more strap attachment protrusions 22 can be reinforced with a mesh of fibers such as nylon to increase strength.

[0029] In some embodiments, the shell material of the underbody support 16 can be reinforced with a mesh of fibers such as nylon embedded in the shell material during the extrusion process of the shell material. The fiber reinforcement can be included in the lower shell layer, the upper shell layer, or both shell layers. The reinforcing fibers prevent the shell material from stretching or deforming when a heavy patient is placed in a steep Trendelenburg position, and create a sliding force between the layers of the underbody support, or between the underbody support 16 and the operating table mattress 30 or the operating table top 64. This reinforced structure of the underbody support 16, together with the straps 18A, 18B connected to the side rails 20 of the operating table 4 or the Velcro® attachments to the operating table top 64, and the reinforced structure of the strap attachment protrusions 22 of the underbody support 16, ensures that the underbody support 16 remains stable, does not shift or slide when the patient is placed in a steep Trendelenburg position. In some embodiments, this durable structure of the underbody support 16 also prevents deformation and stretching in any direction parallel to the plane of the support, and thus prevents sliding between the underbody support 16 and the operating table 4. The stability provided by this structure, and its non-deformability in response to the weight of the patient pulling on the slope of the operating table 4, is in contrast to the relatively fragile and flexible structure of conventional disposable fixation pads. As shown in FIGS. 5 and 6, a conventional (e.g., flexible) fixation pad 26 easily deforms in response to a force applied parallel to the plane of the fixation pad 26, and this deformation results in a slide between the fixation pad 26 and the portion 12 of the operating table mattress 30.

[0030] Furthermore, as shown in FIG. 5, such a type of fixed pad 26 includes pad straps 28A, 28B that secure the fixed pad 26 to the side rail 20 of the operating table 4. However, as shown in FIG. 6, securing these types of fixed pads 26 to the side rail 20 allows for a natural 1 - 3 inch slip between the fixed pad 26 and the operating table 4. This slip in this type of fixed pad 26 is due to the force of the patient's weight being applied perpendicular to the direction of the non - durable and stretchable pad straps 28A, 28B that are adhered to the fixed pad 26, which is typically made of a stretchable sheet of flexible visco - elastic foam. These pad straps 28A, 28B, which are vertically oriented, non - durable, flexible, and stretchable, are used in combination with a conventional fixed pad 26 (which is often a flexible and deformable foam) to stretch and bend in combination, allowing the fixed pad 26 to slide the operating table mattress 30 downward by up to 3 inches in a steep Trendelenburg position before the fixed pad 26 stops the sliding. When a force perpendicular to the side rail 20 is applied to the pad straps 28A, 28B adhered to the fixed pad 26 (when such a pad is a flexible foam pad), it is not possible to prevent the movement of the table sliding downward along the steep slope of the incline. The side rail 20 of the operating table 4 is a convenient attachment point for known devices, but using the above - mentioned pad straps 28A, 28B and fixed pad 26, it is not possible to prevent the inclination of the operating table 4 from sliding downward by 1 - 3 inches in the Trendelenburg position.

[0031] In some embodiments, as shown in FIGS. 7 and 7A, a sheet of fabric 32 at least partially coated on both sides with friction enhancing elements 34 can be interposed between the patient 2 and the underbody support 16 to increase the coefficient of friction therebetween. The friction enhancing elements 34 can be a high friction plastic or rubber, or a material having similar properties. Examples of materials for the friction enhancing elements 34 can be PVC, silicone, polyethylene, or other plastic or rubber materials that can be applied as a three-dimensional pattern or three-dimensional raised dots on the fabric. As shown in FIGS. 8 and 9, the friction enhancing elements 34 can be in the form of a pattern or dots that grip, on the one hand, the upper surface of the underbody support 16 and, on the other hand, the back of the patient 2, dramatically increasing the coefficient of friction between the patient 2 and the surface of the underbody support 16 and preventing the two from sliding relative to each other. Alternatively, the friction enhancing elements 34 can be applied directly to the upper surface of the underbody support 16. The upper surface may also be referred to as the patient interface surface.

[0032] In some embodiments, the sheet of fabric 32 is interposed between the upper surface of the underbody support 16 and the back of the patient 2 to increase the coefficient of friction between these two surfaces. The sheet of fabric 32 can be either a woven or non-woven fabric and may be made of any durable fiber such as polyester, rayon, nylon or cotton. Other fibers for the sheet of fabric 32 are contemplated. In some embodiments, when a fluid impermeable layer is desired, the sheet of fabric 32 of the present disclosure may be made of a plastic film, or a plastic film coated or laminated on one or both sides of a fibrous sheet of fabric. The plastic film layer can be made of polyethylene, polypropylene, PVC, urethane or other suitable films.

[0033] In some embodiments, the fabric sheet 32 is at least partially coated on its upper surface 36 with friction enhancing elements 34. The friction enhancing elements 34 can be three-dimensional friction enhancing elements of plastic or rubber, such as a three-dimensional raised pattern of circular, square, rectangular, or oval elements. In some embodiments, the friction enhancing elements 34 have a diameter or cross-section between 0.1 inch and 0.5 inch. The friction enhancing elements 34 include, but are not limited to, PVC foam, viscoelastic PVC foam, silicone, viscoelastic polyurethane foam, other viscoelastic polymer foams, urethane, PVC, and other polymers and rubbers.

[0034] In some embodiments, as shown in FIGS. 10 and 11, the fabric sheet 32 is partially coated with friction enhancing elements 34 on both the upper surface 36 and the lower surface 38. The friction enhancing elements 34 can be three-dimensional friction enhancing elements of plastic or rubber, such as a three-dimensional raised pattern of circular, square, rectangular, or oval elements. In some embodiments, the friction enhancing elements 34 on the upper surface 36 and the lower surface 38 are three-dimensional friction enhancing elements that are sized and positioned directly opposite each other on each side of the fabric sheet 32. As used herein, friction enhancing elements 34 that are directly opposite each other in both size and location refer to friction enhancing elements 34 that are positioned directly opposite each other on opposite sides of the fabric sheet 32 and have exactly the same dimensions (or substantially the same dimensions) as each other. The direct opposition of the friction enhancing elements 34 on both sides of the fabric sheet 32 improves the transmission of force between the upper surface of the underbody support 16 and the patient's back at that point. The ability of the friction enhancing elements 34 on each side of the fabric sheet 32 to increase the coefficient of friction by indenting the patient's back 2 on the one hand and the underbody support 16 on the other hand is reduced if the friction enhancing elements 34 on each side of the fabric sheet 32 are not directly opposed. In some embodiments, the friction enhancing elements 34 are three-dimensional friction enhancing elements intended to press against the patient's skin to create small depressions and increase the mechanical interaction between the fabric sheet 32 and the patient's skin. This mechanical interaction between the fabric sheet 32 and the patient's skin indents the skin and increases the normal coefficient of friction between the two surfaces. By positioning the friction enhancing elements 34 directly opposite each other on each side of the fabric sheet 32, the ability of each friction enhancing element 34 to transmit force from the underbody support 16 to the patient's back is maximized.

[0035] In some embodiments, as shown in FIGS. 9, 10, and 11, the friction enhancement element 34 on the upper surface 36 of the fabric sheet 32, which can be a three-dimensional raised pattern of the friction enhancement element, may form a matrix leaving the fabric sheet 32 with holes 40 in the regions between the raised patterns of the friction enhancement element. The holes 40 in the fabric sheet 32 can advantageously allow for free passage of heat, air, and moisture through the fabric sheet 32. When the underbody support 16 is a heated underbody support, the holes 40 allow heat from the underbody support 16 to pass freely through the fabric sheet 32 and reach the patient, enabling effective warming. This is in contrast to the insulating quality of conventional (e.g., foam-containing) fixed pads 26 that impede effective underbody patient warming. The holes 40 in the fabric sheet 32 of the present disclosure can also advantageously allow for free passage of moisture through the fabric sheet 32, contacting the patient's skin and removing sweat or skin preparation disinfectant fluid that may make the skin vulnerable to pressure injury.

[0036] In some embodiments, as shown in FIG. 12, the structure of the fabric sheet 32, which is three-dimensional and has friction enhancing elements 34 directly facing each other on both sides of the fabric and has holes or uncoated spaces 40 between the friction enhancing elements 34, may be made by starting with a scrim 42 that can be a fabric scrim made of polyester or other suitable fibers. The yarns 44 of the scrim 42 can be woven or knitted, for example, into a pattern such as a checkerboard pattern having open spaces 46 between the matrix of the yarns 44. The open spaces 46 between the yarns can be between about 0.05 inches and about 0.25 inches in diameter. Similar to the black spaces on the checkerboard pattern, additional yarns 48 can be added in the open spaces 46 during the weaving or knitting process. As shown in FIG. 9, when the fabric sheet 32 of this scrim 42 is coated with a foamed PVC compound, the liquid PVC adheres to the spaces where the additional yarns 48 are added, and open holes or uncoated spaces 40 are formed in the open spaces 46 where no additional yarns are added. The foamed PVC can naturally and advantageously form friction enhancing elements 34 that can be three-dimensional friction enhancing elements directly facing each other on both sides of the fabric sheet 32 where the additional yarns 48 are added, leaving holes or uncoated spaces 40 between the friction enhancing elements 34 (available from Kittrich Corp).

[0037] In some embodiments, the area of one hole 40 may advantageously be smaller than the area of one of the friction enhancing elements 34. In some embodiments, the area of one of the holes 40 can advantageously be less than 0.1875 square inches. Holes 40 larger than 0.1875 square inches are disadvantageous both for the area of the skin that supports the patient's body weight and for the natural adhesiveness between the friction enhancing elements 34 and the skin. Further, holes 40 larger than 0.1875 square inches can create a hydrostatic pressure gradient within the patient's skin protruding into the holes 40, resulting in a pattern of petechial hemorrhages or bruises.

[0038] In some embodiments, as shown in FIG. 10, the friction enhancing element 34 formed on a scrim 42 (e.g., a coarse weave) of the fabric sheet 32 has an overall thickness of about 0.125 inches. Such a friction enhancing element 34 can be a foamed PVC three-dimensional friction enhancing element. The Applicant has discovered that these 0.125-inch thick dots or beads in a matrix formation with space between the dots can cause mild petechial hemorrhages (bruises or extravasation, leakage of blood into unsupported skin tissue pushed into the open spaces of a checkerboard pattern). This problem of petechial hemorrhages can be alleviated, at least when the friction enhancing elements 34 are rounded three-dimensional friction enhancing elements, by flattening the friction enhancing elements 34 on the upper surface 36 of the fabric sheet 32. In some embodiments, as shown in FIG. 13, a fabric sheet 32 having a friction enhancing element 34 that is a foamed PVC three-dimensional friction enhancing element and has open spaces 46 therebetween can be flattened by passing it through a thermal lamination process that can flatten the three-dimensional dots from a thickness of about 0.125 inches to a thickness of about 0.05 - 0.10 inches. In some cases, each open space 46 is individually shown in the drawing as reference numerals 46A and 46B. Even when the foamed PVC three-dimensional friction enhancing elements are flattened, the checkerboard pattern of the holes 40 between the friction enhancing elements 34 does not close, but the surface area of the holes 40 becomes slightly smaller compared to the surface area of the adjacent friction enhancing elements 34. In some embodiments, a heat laminator can heat the fabric sheet 32 before passing it between two compression rollers. Alternatively, the fabric sheet 32 can pass between two compression rollers, one or both of which are heated. The flattened friction enhancing elements 50 (which can be foamed PVC three-dimensional friction enhancing elements) having smaller diameter holes 40 therebetween can not only cause petechial hemorrhages but also do not grip the patient as effectively.

[0039] When the friction enhancement element 34 is a foamed PVC three-dimensional friction enhancement element, by flattening these friction enhancement elements 34 in the heat laminator process, the surface characteristics of the foamed PVC material also change, and the adhesiveness substantially increases. The heating and compression process destroys the normal "skin" formed on the surface of the foam when it cures. When the surface "skin" is destroyed, the "highly adhesive" internal foam is exposed. The highly adhesive PVC foam further increases the coefficient of friction between the underbody support 16 and the patient 2. The "highly adhesive" PVC foam can adhere better to the patient than the foam with skin, but does not adhere well to the adhesive. The exposed plasticizer in the foam hinders the adhesion of the adhesive. Therefore, when it is intended that a piece of the fabric sheet 32 is adhesively bonded to the pull-out sheet 76 or other materials, it may be advantageous to adhesively bond to the non-compressed side of the fabric sheet 32. The original "skin" characteristics of the foamed PVC material on the lower surface 38 help with the adhesive bonding. In the presence of heat from the underbody support 16 and pressure from the weight of the patient 2, the highly adhesive foamed PVC may leave an obstructive residue of the foam adhered to the underbody support 16. In some embodiments, this adhesive residue can be prevented by heating and flattening the friction enhancement element 34 on the upper surface 36 of the fabric sheet 32 while keeping the adhesiveness suppressed without substantially changing the original "skin" characteristics of the foamed PVC material on the lower surface 38. The original "skin" characteristics of the foamed PVC material on the lower surface 38 help prevent the residue of the foam from adhering to the underbody support 16.

[0040] In some embodiments, as shown in FIG. 14, the flattening of the friction enhancement element 34 to form the friction enhancement element 50 on the upper surface 36 of the fabric sheet 32 can be achieved by heating the upper surface and / or heating one or both of the upper compression rollers. In some embodiments, during the compression process, by heating the upper surface, minimally heating the lower surface, and / or cooling the lower compression roller, the original structure, shape, and surface integrity of the friction enhancement element 34 on the lower surface 38 of the fabric sheet 32 can be maintained.

[0041] In some embodiments, a sheet of fabric 32 having friction enhancing elements 34 (which may be foamed PVC three-dimensional friction enhancing elements) and having uncoated spaces or holes 40 therebetween can be flattened and thinned by passing through a heat compression process. The heat compression process can advantageously produce a patient fixation device that has a very thin thickness (compared to conventional thick foam pad fixation devices) while retaining most of the gripping characteristics.

[0042] In some embodiments, the underbody support 16 can also function as a capacitive coupled electrosurgical ground electrode. For effective capacitive coupling, it is necessary to separate two conductors by only a thin dielectric (electrical insulator). Capacitive coupling of RF electrical energy is most efficient and effective when the patient's skin is separated from the ground antenna by a thin dielectric or electrical insulating material. A dielectric thicker than, for example, 0.5 inches impedes effective capacitive coupled electrosurgical grounding. The friction enhancing elements 34 (which may be three-dimensional friction enhancing elements) on the fabric sheet 32 of the present disclosure create a thin dielectric. The thickness of this dielectric can be further thinned by heating and compressing the friction enhancing elements 34 between two rollers as described above to form the flattened friction enhancing elements 50, which further enhances the effectiveness of capacitive coupling. In some embodiments, the thin nature of the fabric sheet 32 of the present invention (such as a thickness less than 0.125 inches) enables effective capacitive coupled electrosurgical grounding. Capacitive coupling can be further enhanced by the holes or uncoated spaces 40 formed between the friction enhancing elements 34, 50, where there are no additional electrical insulating (dielectric) properties caused by the fabric sheet 32. The invention of the present disclosure is uniquely suitable for use in capacitive coupled electrosurgical grounding. In contrast, conventional (e.g., thick foam) fixation pads 26 impede the occurrence of effective capacitive coupling.

[0043] In some embodiments, the total thickness of each of the (e.g., three-dimensional) friction enhancing elements 34 on both the upper 36 and lower 38 surfaces of the fabric sheet 32 is less than 0.25 inches. In some embodiments, as shown in FIG. 15, a layer 52 of soft foam material is adhesively laminated to the upper surface 36 of the fabric sheet 32. Optionally, the layer 52 of soft foam material has a thickness of less than 0.75 inches. Laminating the layer 52 of soft foam material to the fabric sheet 32 substantially increases the strength, stability, and tear resistance of the layer 52 of soft foam material. Compared to known fixation pads, since the resulting patient fixation overlay 54 has a minimal thickness, the bolster effect that occurs particularly when the non-weight-bearing foam surrounding the patient at the shoulder is thick is eliminated. When the layer 52 of soft foam material is relatively thin, the patient cannot sink into the foam noticeably to create a bolster effect. This is advantageous because the effectiveness of patient fixation by the bolster effect is limited by the patient's weight and the shape of their shoulder. For example, a heavy patient and a rounded shoulder can exceed the ability of a bolster to prevent slipping.

[0044] In some embodiments, by limiting the thickness to less than 0.75 inches, either minimizing or eliminating the weight-limited patient fixation bolster effect in the patient fixation overlay 54, a patient fixation effect is obtained that is determined only by the approximate coefficient of friction between the patient and the patient fixation overlay 54. The coefficient of friction is, by definition, independent of the patient's weight. In some embodiments, due to the physical properties of the coefficient of friction, the effectiveness of this patient fixation device is independent of the patient's weight and is limited only by the descent angle. Thus, due to the physical properties of the coefficient of friction, the patient fixation device of the present disclosure can accommodate patients of any size or weight without limitation. The instructions for use of this device may only limit the descent angle. The most well-known bolster type patient fixation devices are limited to a specific weight, typically 300 - 400 pounds. The instructions for use of bolster type devices limit both the patient's descent angle and weight.

[0045] In some embodiments, as shown in FIGS. 7 and 7A, the patient fixation overlay 54 is advantageously secured to at least a portion of the foot end of the portion 12 of the operating table mattress 30 that supports the patient's torso on the operating table 4. In some embodiments, advantageously, the patient fixation overlay 54 is secured to at least a portion of the foot end 10 of the underbody support 16. By securing the patient fixation overlay 54 to at least a portion of the foot end 10 of the operating table mattress 30 or the underbody support 16 that supports the patient's torso, a secure bond is created between the two layers when the patient is in the Trendelenburg position. The portion 12 of the operating table mattress 30 or the underbody support 16 can be securely attached to the operating table 4, and the patient fixation overlay 54 can be securely attached to at least a portion of the foot end 10 of the underbody support 16 or to the operating table mattress 30. Thus, the patient fixation overlay 54 is securely and independently, indirectly attached to the operating table 4.

[0046] As shown in FIG. 3, the foot end 10 of the portion 12 of the operating table mattress 30 that supports the patient's torso on the operating table 4 typically includes a perineal notch 14 at the center of the foot end of the portion 12 of the operating table mattress 30. The perineal notch 14 of the section 12 of the operating table mattress 30 is typically a tapered 3-6 inch depression at the foot end of the operating table mattress 30, having a width of typically 10-14 inches at the open side of the depression and 4-8 inches at the closed side of the depression. On the outside of each side of the perineal notch 14 are lateral extensions 56 of the operating table mattress 30. The lateral extensions can extend about 4-6 inches from each side of the perineal notch 14. The perineal notch 14 allows the patient's perineum to droop slightly over the central end of the operating table mattress 30, while allowing the lateral extensions 56 to provide support to the sides of the buttocks when the patient's legs are abducted. The perineal notch 14 serves to allow the surgeon or robot to access the patient's perineum unobstructed.

[0047] In some embodiments, the perineal notch 14 of the underbody support 16 may be a tapered 3 - 6 inch depression at the foot end of the underbody support 16, which may have a width of 10 - 20 inches at the open side of the depression and a width of 4 - 12 inches at the closed side of the depression.

[0048] In some embodiments, as shown in FIGS. 7 and 7A, the patient fixation overlay 54 is preferably wrapped around at least a portion of the foot end 10 of the operating table mattress 30 or the underbody support 16 and is secured to at least a portion of the foot end 10 of the portion 12 of the operating table mattress 30 or the underbody support 16 that supports the patient's torso on the operating table 4 by a foot end extension 58 of a cloth sheet 32 that is fixed under the operating table mattress 30 or the underbody support 16. In some embodiments, the foot end extension 58 is a separate piece of material added to the patient fixation overlay 54 as a securing portion.

[0049] In some embodiments, the width of the foot end extension 58 is less than the width of the patient fixation overlay 54. In some embodiments, the width of the foot end extension 58 is preferably approximately equal to the width of the closed side of the depression of the perineal notch 14 of the operating table mattress 30 or the underbody support 16. In some embodiments, the width of the foot end extension 58 can be between 4 - 20 inches. In some embodiments, the width of the perineal notch 14 of the underbody support 16 may be greater than the width of the perineal notch 14 of the operating table mattress 30. When the perineal notch 14 of the underbody support 16 is wider than the perineal notch 14 of the operating table mattress 30, this may advantageously allow a wider, and thus stronger, foot end extension 58 of the cloth sheet 32 to be wrapped around the perineal notch 14 of the underbody support 16 and still fit within the perineal notch 14.

[0050] In some embodiments, the patient fixation overlay 54 is advantageously wrapped around at least a portion of the head end 62 of the surgical table mattress 30 or the portion 12 of the underbody support 16 that supports the patient's torso and is secured to at least a portion of the head end 62 of the surgical table mattress 30 or the portion 12 of the underbody support 16 that supports the patient's torso by a head end extension 60 of a cloth sheet 32 that is fixed under the surgical table mattress 30 or the underbody support 16. In some embodiments, the head end extension 60 for securing the head end of the patient fixation overlay 54 is a separate cloth sheet that is added as an extension to the cloth sheet 32.

[0051] In the Trendelenburg position, the force vector of the patient's weight is applied parallel to the direction of the cloth sheet 32 that wraps around at least a portion of the foot end 10 of the surgical table mattress 30 or the portion 12 of the underbody support 16 that supports the patient's torso. In some embodiments, the fastening mechanism at the foot end extension 58 of the cloth sheet 32, which is wrapped around at least a portion of the foot end 10 of the surgical table mattress 30 or the portion 12 of the underbody support 16 that supports the patient's torso and is fixed under the surgical table mattress 30 or the underbody support 16, applies a force vector that is directly opposite to the direction of the force applied by the patient's weight when the patient is in the Trendelenburg position. The secure connection provided by the foot end extension 58 of the cloth sheet 32, which is wrapped around at least a portion of the foot end 10 of the surgical table mattress 30 or the portion 12 of the underbody support 16 that supports the patient's torso and is fixed under the surgical table mattress 30 or the underbody support 16, does not stretch or bend and thus substantially limits (e.g., prevents) slippage or deformation between the patient fixation overlay 54 and the surgical table mattress 30 or the underbody support 16. In some embodiments, the fastening mechanism at the foot end 10 of the surgical table mattress 30 or the portion 12 of the underbody support 16 that supports the patient's torso creates an adhesion force vector, which is preferably directly opposite to the force vector of the patient sliding downward along the inclination of the surgical table 4 in the Trendelenburg position. This is in contrast to the known fixation pads 26 where the adhesion force vector is lateral or perpendicular to the force vector of the patient sliding downward along the inclination of the surgical table 4 in the Trendelenburg position. A vertical force vector for preventing slippage is not as safe as a parallel force vector.

[0052] In some embodiments, by wrapping a sheet 32 of fabric around the foot end of the operating table mattress 30, an anchor segment is created that is substantially perpendicular to the foot end of the mattress, and this anchor segment is oriented perpendicular to the force vector of the patient's weight that slides the operating table downward in the Trendelenburg position. If the mattress is not properly fixed to the table, or if there is any slippage between the layers of material forming the mattress, or if there is crushing and displacement of the foam of the mattress, the vertical orientation of attaching the fabric sheet 32 around the foot end of the operating table mattress 30 cannot prevent the patient from moving downward on the tilted operating table. In some embodiments, the problem associated with attaching the fabric sheet 32 around the foot end of the operating table mattress 30 is that in a state where a heavy load (such as >300 pounds) is applied in a steep Trendelenburg position (>35° etc.), the fabric sheet 32 at the foot end of the operating table mattress 30 is pulled by the tensile force of the patient's weight until it reaches an angle of about 45 - 55° with respect to the upper surface of the operating table, and the foam at the upper foot edge of the surgical mattress pad with a thickness of 3 inches or 4 inches is compressed at the part where the fabric sheet 32 is attached around the foot end of the operating table mattress 30. At this angle, the force vector is sufficient to prevent further slippage, but the patient slides 3 - 4 inches downward on the tilted operating table before stabilizing. A 3 - 4 inch slippage is unacceptable if it occurs during surgery.

[0053] In some embodiments, the foot end extension 58 and the head end extension 60 of the fabric sheet 32 for wrapping around at least a portion of the foot end 10 and the head end 62 of the operating table mattress 30 or the underbody support 16 respectively include one or more elements that improve the frictional coupling between the foot end extension 58 and the head end extension 60 and either or both of the underside of the underbody support 16, the portion 12 of the operating table mattress 30 that supports the patient's torso, and / or the upper part 64 of the operating table. In some embodiments, the one or more elements that improve this frictional coupling can be plastic or rubber and include a low - adhesion adhesive or a three - dimensional friction - enhancing element applied to the foot end extension 58 and the head end extension 60 of the fabric sheet 32.

[0054] For example, any low-adhesion adhesive known in the art, including but not limited to the adhesives used in Post-it Notes (registered trademark, available from 3M Corporation), can be used to improve this frictional coupling. The plastic or rubber three-dimensional friction-enhancing elements that can be used include, but are not limited to, silicone, viscoelastic polyurethane foam, viscoelastic PVC foam, other viscoelastic polymer foams, urethane, PVC, and other polymers and rubbers. The friction-enhancing element 34, which can be a three-dimensional friction-enhancing element, may be applied to the foot-end extension 58 and the head-end extension 60 of the cloth sheet 32, or may be a separate cloth piece adhesively bonded, thermally bonded, or stitched to the cloth sheet 32 forming the foot-end extension 58 and the head-end extension 60.

[0055] In some embodiments, the foot-end extension 58 at the foot end of the cloth sheet 32 that joins the neck 70 of the cloth sheet 32 or the foot end of the cloth sheet 32 to the fixing part 66 (which can be plastic, metal, fiberboard, or other suitable material) can be strengthened by melting and compressing a friction-enhancing element such as PVC foam, viscoelastic PVC foam, viscoelastic polyurethane foam, or polyurethane foam in the form of a film. Compressing these materials with a heat press or an RF press causes the foam structure to collapse and the material to change like a film. The film-like structure is stronger than the foam structure and, in some applications, can be an excellent configuration for wrapping around the ends of the operating table mattress 30 or the underbody support 16.

[0056] In some embodiments, as shown in FIG. 15, a layer 52 of soft foam material may be adhesively laminated to the upper surface 36 of the cloth sheet 32. Laminating the layer 52 of soft foam material to the cloth sheet 32 advantageously utilizes a secure non-slip attachment of the cloth sheet 32 or the foot end extension 58 wrapped around the foot end 10 of the portion 12 of the operating table mattress 30 or the underbody support 16 that supports the patient's torso, and securely captures the cloth sheet 32 or the foot end extension 58 between the underbody support 16 and the operating table mattress 30, or between the operating table mattress 30 and the operating table upper portion 64. When the cloth sheet 32 is securely attached, the layer 52 of soft foam material is also securely attached (e.g., laminated to the upper surface of the cloth sheet 32). This is in contrast to the known pad straps 28A, 28B that attach the layer of soft foam material to the side rail 20 of the operating table 4 as shown in FIG. 6. The cloth sheet 32 also reinforces the layer 52 of soft foam material and allows the layer 52 of soft foam material to be relatively thin, for example, from a thickness of 0.25 to 0.75 inches. The cloth sheet 32 prevents the layer 52 of soft foam material from tearing, stretching, or deforming under the weight of a patient in the Trendelenburg position.

[0057] In some embodiments, the layer 52 of soft foam material can be any suitable type of foam material. In some embodiments, the layer 52 of soft foam material can be a viscoelastic urethane foam or a urethane skin foam. Other foam materials, including other viscoelastic foam materials, are contemplated and can be used as the layer 52 of soft foam material. The layer 52 of soft foam material can have any thickness between about 0.25 inches and about 3 inches. In some embodiments, the layer 52 of soft foam material can have a thickness of less than 0.5 inches.

[0058] In some embodiments, a method is provided for supporting and restricting the sliding movement of a patient 2 on an operating table 4. The method includes (i) providing an underbody support 16 configured to support the patient 2 on the operating table 4, the underbody support 16 including a compressible material layer having an upper surface configured to face the patient 2 on an opposite side of a base layer having a lower surface configured to face the operating table 4; (ii) coupling the underbody support 16 to the operating table 4; (iii) disposing a cloth sheet 32 between the upper surface of the underbody support 16 and the patient 2, the cloth sheet 32 including friction enhancing elements 34 on one or both sides of the cloth sheet 32, the cloth sheet 32 being configured to grip both the underbody support 16 and the patient 2 to prevent the patient from inadvertently slipping off the underbody support 16; and (iv) positioning the patient 2 on the underbody support 16.

[0059] In some embodiments, it may be advantageous to secure the cloth sheet 32 or other securing overlay to the side rails 20 of the operating table 4. Securing to the side rails 20 of the operating table 4 is not a new idea; for example, Pigazzi discloses securing a patient fixation device to the side rails 20 by straps in U.S. Patent No. 8,464,720. The inventors disclose securing a mattress overlay device to the side rails 20 by straps in U.S. Patent No. 10,765,580. In both of these prior art examples, the device was secured to the side rails 20 by straps 18.

[0060] Figures 5 and 6 show a mattress overlay 26 of the Pigazzi design that uses straps 28A and 28B to secure the overlay to the side rails of the operating table 4. FIG. 6 also shows a Pigazzi-designed mattress overlay 26 that slides relative to the mattress 12 and slides towards the head end when in the head-down Trendelenburg position, which is a well-known problem with the Pigazzi design.

[0061] Figures 17-21 are enlarged views of the focal region 66 shown in FIG. 16.

[0062] As shown in FIG. 17, the patient 2 may start on the horizontal operating table 4, and the vertical straps 18A and 18B properly position the patient 2, the cloth sheet 32, and the operating table mattress 12. On the horizontal operating table 4, there is no force attempting to move the patient towards either the foot end or the head end of the operating table 4. The holding force vector angle 68 (the angle between the strap 18B and the cloth sheet 32) is approximately 90°. This is the worst angle that can be in preventing the inclined tabletop from sliding downward. Ideally, the best holding force vector angle 68 is 0°. This is parallel to the cloth sheet 32 and most directly opposes the inclined tabletop from sliding downward. When the operating table 4 is horizontal, the foot end of the mattress 32 may coincide with the foot end of the body portion of the operating table 4.

[0063] As shown in FIG. 18, straps 1818A and 1818B may not appropriately prevent one or more of the following: the fabric sheet 32 from sliding relative to the mattress 12, the mattress 12 from sliding relative to the operating table 4, the layers of material forming the mattress 12 from sliding relative to each other, or the foam of the mattress 12 from compressing and deforming under pressure. FIG. 18 shows an example of a mattress 12 sliding on the operating table 4 when the head end of the operating table 4 is tilted downward into the "Trendelenburg" position. As shown in FIG. 18, straps 1818A and 1818B connected between the fabric sheet 32 and the side rails of the operating table 4 shift from a vertical orientation and deform to form a holding force vector angle 1868 of 45 to 55° with respect to the fabric sheet 32, creating a force vector that can counteract the weight of the patient 2 sliding downward with the tilt of the operating table 4. If the mattress 12 is not properly fixed to the operating table 4, an inevitable result of the rotation of straps 1818A and 1818B is that the mattress 12 can slide downward with the tilt of the operating table 4, resulting in mattress movement 1870.

[0064] The inventors tested under severe conditions where a 400-pound "patient" was tilted at 45° without fixing the mattress 12 to the top of the operating table 4, unlike when the Velcro® that normally secures the mattress 12 to the operating table 4 is old and damaged. Under these severe conditions, the independent straps 1818A and 1818B fixed to the four corners of the fabric sheet 32 allow the mattress 12 to slide approximately 4 inches downward on the table before stopping the sliding motion (mattress movement 1870).

[0065] FIG. 19 also shows an example of a mattress 12 that slides on the operating table 4 when the head end of the operating table 4 is tilted downward to the "Trendelenburg" position. In some examples, as shown in FIG. 19, the straps 1818A and 1818B can be replaced by side flaps 72. In some examples, as shown in FIG. 19, the side flaps 72 can be connected between the foot end of the cloth sheet 32 and the side rails of the operating table 4, near the foot end of the cloth sheet 32. In contrast to individual straps such as 1818A and 1818B that can rotate easily, the side flap 72 extends between attachment points 1974A and 1974B and is made of a sheet of a strong but flexible material that naturally resists rotation. Instead of creating a preferred holding force vector angle 1968 by rotating the straps 1818A and 1818B up to about 45°, some examples of the invention of the present disclosure fill the space between the virtual straps with a side flap 72 material that creates a more preferred force vector 1980 and a more preferred holding force vector angle 1968 that is <45° with a rotation that is not large and <45°. When rotation is minimized, mattress movement 1970 is also minimized.

[0066] The inventors tested a 400-pound "patient" tilted at 45° under harsh conditions where the mattress 12 was not fixed to the top of the operating table 4. Under these conditions, the side flaps 72, which were fixed to each side of the cloth sheet 32 near the foot end and attached to the side rails of the operating table 4 at attachment points 1974A and 1974B, allowed the mattress 12 to slide about 2 inches downward on the table before stopping the sliding motion (mattress movement 1970). The 2-inch mattress movement 1970 is exactly half of the 4-inch mattress movement 1870 observed with the straps 1818A and 1818B.

[0067] FIG. 20 also shows an example of a mattress 12 that slides on the operating table 4 when the head end of the operating table 4 is tilted downward to the "Trendelenburg" position. In some examples, as shown in FIG. 20, the straps 1818A and 1818B may be replaced by side flaps 76. In some examples, as shown in FIG. 20, the side flap 76 may be connected between the fabric sheet 32 and the side rail of the operating table 4 near the foot end of the fabric sheet 32. In contrast to FIG. 19, the example of FIG. 20 connects to the side rails of the operating table 4 at three attachment points 2074A, 2074B, and 2074C. In contrast to individual straps such as 1818A and 1818B that can rotate easily, the side flap 76 extends between the attachment points 2074A, 2074B, and 2074C and is made of a sheet of a strong but flexible material that naturally resists rotation. Instead of creating a preferred holding force vector angle 1868 by rotating the straps 1818A and 1818B up to about 45°, some examples of the invention of the present disclosure create more preferred force vectors 2080A and 2080B and a more preferred holding force vector angle 2068 of <45° with a rotation of <45° that fills the space between the attachment points 2074A, 2074B, and 2074C with side flap 72 material. When rotation is minimized, mattress movement 2070 is also minimized.

[0068] The inventors tested a 400-pound "patient" at a 45° incline under harsh conditions where the mattress 12 was not fixed to the top of the operating table 4. Under these conditions, the side flaps 76, which were fixed to each side of the fabric sheet 32 near the foot end and attached to the side rails of the operating table 4 at the attachment points 2074A, 2074B, and 2074C, allowed the mattress 12 to slide approximately 1 inch downward on the table before stopping the sliding motion (mattress movement 2070). The 1-inch mattress movement 2070 is exactly 1 / 4 of the 4-inch mattress movement 1870 observed with the straps 1818A and 1818B.

[0069] FIG. 21 also shows an example of a mattress 12 that slides on the operating table 4 when the head end of the operating table 4 is tilted downward to the "Trendelenburg" position. In some examples, as shown in FIG. 21, the straps 1818A and 1818B may be replaced by side flaps 78. In some examples, as shown in FIG. 21, the side flaps 78 may be connected between the foot end of the fabric sheet 32 and the side rails of the operating table 4 near the foot end of the fabric sheet 32. In contrast to FIG. 20, the example of FIG. 21 connects to the side rails of the operating table 4 at four attachment points 2174A, 2174B, 2174C, and 2174D. In contrast to individual straps such as 1818A and 1818B that can rotate easily, the side flap 78 extends between the attachment points 2174A, 2174B, 2174C, and 2174D and is made of a sheet of strong flexible material that naturally resists rotation. Instead of creating a preferred holding force vector angle 1868 by rotating the straps 1818A and 1818B up to about 45°, some examples of the invention of the present disclosure create more preferred force vectors 2180A, 2180B, and 2180C and a more preferred holding force vector angle 2168 of <45° with a <45° rotation to fill the space between the attachment points 2174A, 2174B, 2174C, and 2174D with the side flap 72 material. When rotation is minimized, mattress movement 2170 is also minimized.

[0070] The inventors tested a 400-pound "patient" at a 45° incline under severe conditions where the mattress 12 was not fixed to the top of the operating table 4. The results of this test are shown in Table 1 below. Under these conditions, the side flaps 78, which were fixed to each side of the fabric sheet 32 near the foot end and attached to the side rails of the operating table 4 at the attachment points 2174A, 2174B, 2174C, and 2174D, allowed the mattress 12 to slide about 1 / 2 inch downward on the table before the sliding motion stopped (mattress movement 2170). The 1 / 2-inch mattress movement 2170 is exactly 1 / 8 of the 4-inch mattress movement 1870 observed with the straps 1818A and 1818B.

[0071] As shown in FIG. 22, the advantageous holding force vector angle 68 of <45° with a rotation of <45° demonstrated in FIG. 21 using four attachment points 2174A, 2174B, 2174C, and 2174D can basically be replicated using three attachment points 2274A, 2274B, and 2274C when the side flap material 82 extends towards the head end beyond the attachment point 2274C. The extension of the side flap material 82 enables the force vector 2280C between the attachment point 2274C and the fabric sheet 32 to create a preferred holding force vector angle 2268, in contrast to the attachment point 2174D in FIG. 21 adjacent to the edge of the side flap material 78.

[0072]

Table 1

[0073] In some examples, the advantages of a smaller holding force vector angle can be summarized in FIG. 26. A side flap 104 having a single side flap hole 2690 is shown attached to a fabric sheet 2632. The side flap 104 is attached to an attachment bracket 2686 at the attachment point 2674. The dotted line 102 represents the perpendicular line between the attachment point 2674 and the fabric sheet 2632. When the side flap 104 extends to the side flap end point 100A (the same distance from the attachment point 2674 to the fabric sheet 2632), the effective force vector 2680A that resists the downward movement of the fabric sheet 2632 and / or the mattress 12 along the inclination of the operating table due to the patient's weight is a holding force vector angle of 45°.

[0074] In some examples, as shown in FIG. 26, when the side flap 104 extends to the side flap end point 100B (twice the distance from the attachment point 2674 to the fabric sheet 2632), the effective force vector 2680B that resists the downward movement of the fabric sheet 2632 and / or the mattress 12 along the operating table tilt due to the patient's weight has a holding force vector angle 2668B of 26.6°, which is a significant improvement over 45° in the first example.

[0075] In some examples, as shown in FIG. 26, when the side flap 104 extends to the side flap end point 100C (three times the distance from the attachment point 2674 to the fabric sheet 2632), the effective force vector 2680C that resists the downward movement of the fabric sheet 2632 and / or the mattress 12 along the operating table tilt due to the patient's weight has a holding force vector angle 2668C of 18.4°, which is an improvement over 26.6° in the second example.

[0076] In some examples, as shown in FIG. 26, when the side flap 104 extends to the side flap end point 100D (four times the distance from the attachment point 2674 to the fabric sheet 2632), the effective force vector 2680D that resists the downward movement of the fabric sheet 2632 and / or the mattress 12 along the operating table tilt due to the patient's weight has a holding force vector angle 2668D of 14°, which is a slight improvement over 18.4° in the third example. In some examples, by gradually lengthening the side flap 104, the holding force vector angles 2668A - D gradually decrease.

[0077] Figure 27 is a photograph of a prototype of an example of the present disclosure. The photograph shows a 45° test stand with an operating table mattress attached. There is a cloth sheet (white line of the material) between the mattress and a sandbag representing a patient. A side flap having three attachment points to an attachment bracket is shown. The force vector can be clearly seen as the stretch of the side flap material, starting from the attachment point and angled to the cloth sheet. In this example, the distance from the end point of the side flap to the right of the right attachment point is approximately 1 / 2 of the distance between the attachment points (this configuration is also shown in FIG. 24). If the distance is shorter, the holding force vector angle at the right attachment point becomes larger compared to the left and central attachment points. When the holding force vector angle becomes larger, the effect of resistance to the downward sliding force becomes lower.

[0078] In some examples, the cloth sheet 32 can be made of a variety of woven and non-woven fabrics including, but not limited to, polyester, polypropylene, rayon, and cotton. Friction enhancing elements have been discussed previously in the present disclosure. Also, it is contemplated that the cloth sheet 32 can be made of a plastic film such as PVC or polyurethane. Further, it is contemplated that the cloth sheet 32 can be made of a plastic film such as PVC or polyurethane reinforced with a woven or non-woven layer.

[0079] In some examples, the fabric sheet 32 may be coated with foam bumps, silicone bumps, or other friction enhancing elements 34 that serve to secure the patient 2 to the fabric sheet 32. In some examples as shown in FIG. 15, the foam layer 52 may be adhesively or thermally bonded to the fabric (or film) sheet 32. In this example, the foam layer 52 is a friction enhancing element 34 that serves to secure the patient 2 to the fabric sheet 32. In some examples as shown in FIG. 15, the layer 52 may be a layer of gel material that can be bonded to the fabric (or film) sheet 32. In this example, the gel layer 52 is a friction enhancing element 34 that serves to secure the patient 2 to the fabric sheet 32. In some embodiments as shown in FIG. 15, the layer 52 may be a layer of minimally adhesive adhesive or other minimally adhesive substance that can be bonded to the fabric (or film) sheet 32. In this example, the minimally adhesive adhesive layer or substance layer 52 is a friction enhancing element 34 that serves to secure the patient 2 to the fabric sheet 32.

[0080] In some examples, such as when the fabric sheet 32 is coated with foam bumps, silicone bumps, or other friction enhancing elements 34, the fabric sheet 32 may be sized to cover most or all of the torso portion of the operating table mattress 12. In some examples, the fabric sheet 32 may extend beyond the ends or sides of the torso portion of the operating table mattress 12. In these examples, the side flaps 72, 76, 78, and 82 may be made of different materials such as, for example, fiber reinforced plastic film, and the side flaps 72, 76, 78, and 82 may be attached to the fabric sheet 32 along the side edges.

[0081] In some examples, such as where the fabric sheet 32 is a base layer to which a foam layer is bonded as shown in FIG. 15 to form a friction enhancing element, the fabric sheet 32 may be larger than the foam layer 52, or the same size as the foam layer 52, or smaller than the foam layer 52. In some examples, the fabric sheet 32 can be a strip of material, such as one or more belts that connect side flaps 72, 76, 78, and 82 on one side to side flaps 72, 76, 78, and 82 on the other side. One or more strips of material can be bonded to the foam layer 52.

[0082] In some examples, the fabric sheet 32 can be made of the same material as the side flaps 72, 76, 78, and 82, or can be cut from the same piece of material as the side flaps 72, 76, 78, and 82, eliminating the need to bond the fabric sheet 32 to the side flaps 72, 76, 78, and 82. For example, the two - holed side flap 72 shown in FIG. 19 can be at the end of a strip of material (wide belt) that crosses the operating table above the mattress 12 and is bonded to the underside of the fabric sheet 32 or the foam layer 52.

[0083] In some embodiments, side flaps 72, 76, 78, and 82 are made of fiber reinforced plastic film. The reinforcing fabric may be made of a variety of woven and non-woven fabrics or scrims including, but not limited to, polyester, polypropylene, rayon, nylon, and cotton. In some examples, it may be preferable to make side flaps 72, 76, 78, and 82 of a polyester woven fabric extruded coated with PVC or polyurethane film. The combination of a film layer and fabric reinforcement minimizes the diagonal stretching of side flaps 72, 76, 78, and 82. The fabric layer reinforces the film layer and prevents tearing of the film layer, while the film layer stabilizes and prevents stretching of the fiber layer, particularly in the diagonal direction. Also, the combination of a film layer and fabric reinforcement creates a durable, minimally stretching, non-tearing attachment point 74 and the entire side flap can essentially become a wide belt. Other fiber reinforcement layer and film layer materials are envisioned. Multilayers are also envisioned.

[0084] In some examples, side flaps 72, 76, 78, and 82 may be attached to fabric sheet 32 using an RF welding process if the materials are similar. For example, a fabric sheet 32 made of a PVC foam applied to a woven fiber scrim can be RF welded to fiber reinforced PVC film side flaps 72, 76, 78, and 82, creating a strong but inexpensive joint. Similarly, a urethane foam can be RF welded or thermally bonded to a urethane film.

[0085] In some examples, side flaps 72, 76, 78, and 82 may be attached to fabric sheet 32 using stitching or an adhesive. Other attachment mechanisms are envisioned including, but not limited to, snaps, hooks, hook and loop (Velcro), and buttons.

[0086] In some examples, side flaps 72, 76, 78, and 82 may be attached to the mattress overlay 16, heated mattress overlay 16, or, in some cases, the operating table mattress 12 to secure the overlay 16 or mattress 12 to the operating table 4. The securing methods of the present disclosure may be particularly important in the case of an operating table mattress 12 that has no attachment to the operating table 4 because the Velcro® has been damaged. It is well known that repeated connecting, disconnecting, and washing of standard Velcro® operating table mattress attachments can damage the Velcro®, in which case the operating table mattress 12 may slide freely off the operating table 4. The securing methods of the present disclosure can provide either secondary or primary securing of the mattress 12 or mattress overlay 16 to the operating table 4.

[0087] In some examples, such as those shown in FIGS. 23 and 24, side flap 82 may be attached to attachment bracket 86 instead of being attached to side rail 20 or side rail standoff posts 84A, 84B, and 84C. In some examples, the attachment may be performed using buttons or hooks attached to attachment points 74A, 74B, and 74C at the top of attachment bracket 86. In some examples, attachment bracket 86 may be attached to the operating table 4 by attachment bracket hooks 88A, 88B, and 88C that catch under side rail standoff posts 84A, 84B, and 84C. Attachment bracket hooks 88A, 88B, and 88C may be of any shape that can catch and engage under one or more of side rail standoff posts 84A, 84B, and 84C. In some examples, attachment bracket 86 may be attached to the operating table 4 by any form of hook, clamp, or strap directly attached to side rail 20 or side rail standoff posts 84A, 84B, and 84C.

[0088] In some examples, the attachment bracket 86 can be made of sheet metal such as stainless steel or aluminum. In some examples, the attachment bracket 86 may be made of molded plastic or die-cut plastic. In some examples, the attachment bracket 86 may be made of carbon fiber or glass fiber reinforced plastic. The plastic attachment bracket 86 has the advantage of being radiolucent and not visible on X-rays. In some examples, the attachment bracket 86 may be of any shape and height suitable for bridging between two or more side rail standoff posts 84A, 84B, and 84C (or corresponding side rails) and may have two or more attachment points 74A, 74B, and 74C.

[0089] In some examples, the attachment points 74A, 74B, and 74C may be the side rail standoff posts 84A, 84B, and 84C. In some examples, the attachment points 74A, 74B, and 74C may be the side rails 20. In some examples, the attachment points 74A, 74B, and 74C may be attachment brackets or clamps attached to the side rail standoff posts 84A, 84B, and 84C. In some examples, the attachment points 74A, 74B, and 74C may be attachment brackets or clamps attached to the side rails 20.

[0090] In some examples, the side flap 82 may include side flap holes 90A, 90B, and 90C, which may be button holes positioned to engage buttons or hooks attached to the attachment points 74A, 74B, and 74C at the top of the attachment bracket 86. In some examples, the side flap holes 90A, 90B, and 90C may be teardrop shaped to be easily hooked onto buttons at the attachment points 74A, 74B, and 74C. In some examples, for the material of the side flap 82 to minimize the possibility of tearing when contacting the button or hook, the pointed ends of the teardrop shape may be oriented towards the force vectors 80A, 80B, and 80C directed towards the attachment points 74A, 74B, and 74C, and the more rounded ends of the teardrop shape may be positioned in contact with the button.

[0091] In some examples as shown in FIG. 23, when the attachment points 74A, 74B, and 74C are lifted above the side rail 20 by being attached along the top of the attachment bracket 86, the holding force vector angle 68 is reduced by approximately half from 68A to 68B. The reduced holding force vector angle at 68B compared to 68A (attachment to the side rail) provides a more favorable force vector 80B (a force vector closer to the optimal 0° holding force vector angle) in resisting the weight of a patient sliding the operating table 4 downward in the Trendelenburg position.

[0092] In some examples, such as those shown in FIG. 25, other mechanisms for attaching the side flap 2582 to the operating table are envisioned. In some examples, the strap 94 can be used to attach the attachment point 2574A to the side rail 20. In some examples, the strap 96 can be used to attach the attachment point 2574B to the side rail stand-off post 84B. In some examples, the strap 96 may be secured by buttons, hooks, snaps, or hook and loop (Velcro®), and other attachment mechanisms are envisioned. In some examples, the strap 98 may be used to attach the attachment point 2574C to the side rail stand-off post 84C by plastic or metal hooks, and other attachment mechanisms are envisioned.

[0093] In some examples, when the side flap 82 is secured to the side rail stand-off post 84 or the side rail 20, the fabric sheet 32 on top of the mattress 12 is gradually stretched and firmly secured from side to side. This security can be advantageous when the patient is on or being repositioned on the operating table 4. What is under the patient, especially if it has a friction-enhancing element such as foam, may easily wrinkle or crease during positioning or repositioning. If unnoticed for a long time during surgery, wrinkles or creases under the patient can cause pressure damage to the patient's skin. By securing the fabric sheet 32 from side to side, wrinkling or creasing is prevented, and thus the risk of damage due to compression is reduced.

[0094] The present disclosure focuses on patient fixation in the Trendelenburg (head-down) surgical position. It should be noted that the fixation mechanisms of the present disclosure are also applicable to other surgical positioning.

[0095] For example, in the present disclosure, it is expected that patients in the reverse Trendelenburg position (head-up position), which can be used during bariatric surgery, can also be fixed to the operating table to prevent them from slipping off the foot end of the operating table. Similar to the Trendelenburg position, the patient lies on a cloth sheet 32 that includes a friction enhancing element 34. In some examples, the cloth sheet 32 may be fixed to the operating table by side flaps 82. In some examples, in contrast to the side flaps 82 in the Trendelenburg position, the side flaps 82 in the reverse Trendelenburg position may be attached near the head end of the cloth sheet 32. The various options disclosed in the present disclosure for attaching the side flaps 82 to the side rail stand-off posts 84 or the side rails 20 include attachment brackets 86 and can be used to attach the side flaps 82 to the side rail stand-off posts 84 or the side rails 20 in the reverse Trendelenburg position.

[0096] The inventors' experience has shown that the cloth sheet 32 including the friction enhancing element 34 of the present disclosure may be too effective when engaging the skin of the patient's buttocks in the reverse Trendelenburg position. Since gravity pulls the patient towards the foot end in the reverse Trendelenburg position, when the patient moves towards the foot end, the fat and skin of the buttocks engaging the friction enhancing element 34 may be rolled up and tucked under the waist, potentially damaging the skin of the buttocks. To prevent this from occurring, the friction enhancing element 34 may be limited to the patient's back (not the buttocks) during the reverse Trendelenburg position. In some examples, this can be achieved by shortening the cloth sheet 32 that includes the friction enhancing element 34, such that the cloth sheet 32 ends above the buttocks, leaving the buttocks on a relatively slippery sheet that normally covers the operating table. In some examples, the buttocks can be protected by adding a layer of a low friction material, such as a non-woven fabric, over the portion of the cloth sheet 32 that includes the friction enhancing element 34 in the area expected to engage the patient's buttocks.

[0097] In some examples, in the present disclosure, it is also contemplated that patients on a substantially horizontal operating table who experience leg extension (strongly pulling on the legs) during certain hip and femur orthopedic surgeries can also be secured to the operating table and prevented from sliding off the foot end of the table. Conventionally, this sliding has been prevented by placing a padded post in the groin area between the patient's legs.

[0098] However, the post often gets in the way of the surgeon during surgery and may cause pressure damage to the perineal nerves and genitals. In orthopedics, there is a trend towards "postless" fixation using a friction-based fixation device against the patient's back instead of a post between the legs.

[0099] Similar to the reverse Trendelenburg position, in some examples, orthopedic patients lie on a cloth sheet 32 that includes a friction-enhancing element 34. In some examples, the cloth sheet 32 may be secured to the operating table by side flaps 82. In some examples, the side flaps 82 for postless orthopedic positioning may be attached near the head end of the cloth sheet 32. The various options disclosed in the present disclosure for attaching the side flaps 82 to the side rail stand-off posts 84 or the side rails 20, including attachment brackets 86, can be used to attach the side flaps 82 to the side rail stand-off posts 84 or the side rails 20 in postless orthopedic positioning. The fixation device of the present disclosure prevents the patient from sliding towards the foot end of the operating table when an extension force is applied to the legs.

[0100] In some examples, in the present disclosure, it is contemplated that patients undergoing robotic heart surgery or other surgeries that require a lateral tilt can benefit from using the fixation device of the present disclosure. In robotic heart surgery, it is often necessary to tilt the patient laterally, usually to the right, so that the robotic scope and instruments have a better angle of entry through the left chest wall. At steep tilt angles, the patient may slide laterally on the operating table if not properly secured.

[0101] Similar to the reverse Trendelenburg position, cardiac surgery patients lie on a sheet 32 of fabric that includes a friction enhancing element 34. In some examples, the sheet 32 of fabric may be secured to the operating table by side flaps 82. In some examples, the side flaps 82 for robotic cardiac surgery positioning may be attached near the head end of the sheet 32 of fabric. The various options disclosed in the present disclosure for attaching the side flaps 82 to the side rail standoff posts 84 or side rails 20, including attachment brackets 86, can be used to attach the side flaps 82 to the side rail standoff posts 84 or side rails 20 in robotic cardiac surgery positioning. The fixation device of the present disclosure prevents the patient from sliding towards the side of the operating table when the table is tilted laterally.

[0102] In some examples, the fixation device of the present disclosure includes a perineal drape 106 as shown in FIG. 16. In some examples, the perineal drape 106 is a sheet of plastic film approximately the width of the operating table. The perineal drape 106 is attached near the foot end of the sheet 32 of fabric either above or below the sheet 32 of fabric and then hangs down from the foot end of the operating table. In some examples, it may be preferable to attach the perineal drape 106 under the sheet 32 of fabric and under the patient's buttocks to prevent blood and fluids from the surgery from contaminating the operating table and mattress. In some instances, the perineal drape 106 can be made of a thin (<.004 inches) plastic film such as polyethylene or PVC. In some examples, the perineal drape 106 may be attached to the sheet 32 of fabric by RF bonding, thermal adhesion, or adhesive bonding.

[0103] Particular embodiments of the invention have been described for purposes of illustration, but it will be apparent to those skilled in the art that numerous variations in detail can be made without departing from the invention as described in the embodiments set forth herein.

Description of the Reference Numerals

[0104] 2 patients 4 operating tables 6 axilla 8 foot end (of the operating table) 10 foot end (of the part of the operating table mattress that supports the patient's torso or the foot end of the underbody support) 12 part of the operating table mattress that supports the patient's torso 14 perineal notch 16 underbody support 18 strap 20 siderail 22 strap attachment protrusion 24 circumferential welding 26 fixing pad 28 pad strap 30 operating table mattress 32 cloth sheet 34 friction enhancement element 36 upper surface (of the cloth sheet) 38 lower surface (of the cloth sheet) 40 hole or uncoated space (hole or space in the cloth sheet) 42 scrim 44 thread 46 open space 48 additional thread 50 flattened friction enhancement element 52 foam material layer 54 patient fixing overlay 56 lateral extension (of the foot end of the part of the operating table mattress that supports the patient's torso) 58 foot end extension 60 head end extension 62 head end (of the part of the operating table mattress that supports the patient's torso) 64 upper part of the operating table

Claims

1. A patient fixation overlay fixed to the operating table for use during surgery where it is necessary to greatly tilt the operating table, comprising: a cloth sheet configured to support the patient's torso on the operating table; the cloth sheet having an upper surface configured to face the patient and a lower surface configured to face the operating table or an underbody support; the cloth sheet including friction enhancement elements applied to at least a portion of the upper surface; the cloth sheet being attached to two or more side flaps extending laterally outward from the side edges of the cloth sheet near the side edges of the cloth sheet; each of the side flaps being attached to the operating table at two or more attachment points; each of the attachment points comprising button holes in the side flap corresponding to buttons or hooks on an attachment bracket; the attachment bracket being adapted to be attached to a side rail stand-off post or side rail of the operating table; A patient fixation overlay in which the distance between adjacent attachment points is greater than the distance between the attachment points and the cloth sheet to naturally create a preferred holding force vector angle of less than 45° between the attachment points and the cloth sheet.

2. The patient fixation overlay according to claim 1, wherein the cloth sheet is made of a woven or non-woven fabric, a plastic film, or a fiber-reinforced plastic film.

3. The patient fixation overlay according to claim 1 or 2, wherein the side flap is made of a woven or non-woven fabric, a plastic film, or a fiber-reinforced plastic film.

4. The patient fixation overlay according to claim 1 or claim 2 or 3, wherein the friction enhancement element includes a foam material or an elastomer applied to the cloth sheet.

5. The patient fixation overlay according to claim 1 or any one of claims 2 to 4, wherein the friction enhancement element includes a foam layer bonded to the cloth sheet.

6. The patient fixation overlay according to claim 1 or any one of claims 2 to 5, wherein the cloth sheet is larger than the area defined by the friction enhancement element.

7. The patient fixation overlay according to any one of claims 1 or 2 to 6, wherein the friction enhancing element includes a layer of foam, and the sheet of fabric is smaller than the area defined by the friction enhancing element.

8. The patient fixation overlay according to any one of claims 1 or 2 to 7, wherein the side flap is RF bonded or thermally bonded to the sheet of fabric.

9. The patient fixation overlay according to any one of claims 1 or 2 to 8, wherein the side flap and the sheet of fabric are made of the same material, and the side flap is stitched or adhesively bonded to the sheet of fabric.

10. The patient fixation overlay according to any one of claims 1 or 2 to 9, wherein the side flap and the sheet of fabric are made of the same material, and the side flap is continuous with the sheet of fabric.

11. The patient fixation overlay according to any one of claims 1 or 2 to 10, wherein the mounting bracket is attached to the side rail stand-off post of the operating table by a hook-like mechanism.

12. The patient fixation overlay according to any one of claims 1 or 2 to 11, wherein the mounting bracket is clamped to the side rail stand-off post or side rail of the operating table.

13. The patient fixation overlay according to any one of claims 1 or 2 to 12, wherein the button holes in the side flap are teardrop-shaped, and the pointed end of the teardrop shape is aligned with the holding force vector.

14. A patient fixation overlay fixed to the operating table for use during surgery that requires a large inclination of the operating table, comprising a sheet of fabric configured to support the patient's torso on the operating table, the sheet of fabric having an upper surface configured to face the patient and a lower surface configured to face the operating table or the underbody support, the sheet of fabric including a friction enhancing element applied to at least a portion of the upper surface, the sheet of fabric being attached to two or more side flaps that extend laterally outward from the side edge of the sheet of fabric near the side edge of the sheet of fabric, each of the side flaps being attached to the operating table at one or more attachment points. Each of the attachment points includes a button hole within the side flap corresponding to a button or hook on the attachment bracket, The attachment bracket is adapted to be attached to a side rail stand-off post or side rail of the operating table, A patient fixation overlay in which the width of each side flap is greater than the distance between the attachment point and the fabric sheet to naturally create a preferred holding force vector angle of less than 45° between the attachment point and the fabric sheet. **Claim 15** A patient fixation overlay fixed to the operating table for use during surgery where it is necessary to greatly tilt the operating table, Comprising a fabric sheet configured to support the patient's torso on the operating table, The fabric sheet has an upper surface configured to face the patient and a lower surface configured to face the operating table or underbody support, The fabric sheet includes a friction enhancing element applied to at least a portion of the upper surface, The fabric sheet is attached to two or more side flaps that extend laterally outward from the side edge of the fabric sheet near the side edge of the fabric sheet, Each of the side flaps is configured to be attached to an attachment bracket or side rail stand-off post or side rail of the operating table at two or more attachment points, A patient fixation overlay in which the distance between adjacent attachment points is greater than the distance between the attachment point and the fabric sheet to naturally create a preferred holding force vector angle of less than 45° between the attachment point and the fabric sheet. **Claim 16** The patient fixation overlay according to any one of claims 15 or 1 to 14, wherein the fabric sheet is made of a woven or non-woven fabric, a plastic film or a fiber-reinforced plastic film. **Claim 17** The patient fixation overlay according to claim 15 or 16, wherein the side flap is made of a woven or non-woven fabric, a plastic film or a fiber-reinforced plastic film. **Claim 18** The patient fixation overlay according to claim 15 or 16 or 17, wherein the friction enhancing element includes a foam material or an elastomer applied to the fabric sheet. **Claim 19** The patient fixation overlay according to any one of claims 15 or 16 to 18, wherein the friction enhancing element comprises a foam layer bonded to the sheet of the fabric.

20. The patient fixation overlay according to any one of claims 15 or 16 to 19, wherein the sheet of the fabric is larger than the area defined by the friction enhancing element.

21. The patient fixation overlay according to any one of claims 15 or 16 to 20, wherein the friction enhancing element comprises a layer of foam, and the sheet of the fabric is smaller than the area defined by the friction enhancing element.

22. The patient fixation overlay according to any one of claims 15 or 16 to 21, wherein the side flap is RF bonded or thermally bonded to the sheet of the fabric.

23. The patient fixation overlay according to any one of claims 15 or 16 to 22, wherein the side flap and the sheet of the fabric are made of different materials, and the side flap is stitched or adhesively bonded to the sheet of the fabric.

24. The patient fixation overlay according to any one of claims 15 or 16 to 23, wherein the side flap is continuous with the sheet of the fabric.

25. The attachment point of the side flap is attached to an attachment bracket using an attachment mechanism selected from the group consisting of buttons and buttonholes, snaps, hooks, hook and loop, straps, clamps, and any combination thereof, according to any one of claims 15 or 16 to 24. The patient fixation overlay described in the item.

26. The buttonhole in the side flap is teardrop-shaped, and the pointed end of the teardrop shape is aligned with the holding force vector, according to any one of claims 25 or 16 to 24. The patient fixation overlay described in the item.

27. The attachment point of the side flap is attached to the side rail stand-off post or the side rail of the operating table using an attachment mechanism selected from the group consisting of buttons and buttonholes, snaps, hooks, hook and loop, straps, clamps, and any combination thereof, according to any one of claims 15 or 16 to 26. The patient fixation overlay described in the item.

28. The patient fixation overlay according to any one of claims 15 or claims 16 to 27, wherein the mounting bracket is attached to the side rail stand-off post of the operating table by a hook-like mechanism.

29. The patient fixation overlay according to any one of claims 15 or claims 16 to 28, wherein the mounting bracket is clamped to the side rail stand-off post or the side rail of the operating table.

30. A patient fixation overlay fixed to the operating table for use during surgery that requires a large inclination of the operating table, comprising a cloth sheet configured to support the patient's torso on the operating table, the cloth sheet having an upper surface configured to face the patient and a lower surface configured to face the operating table or the underbody support, the cloth sheet including a friction enhancement element applied to at least a portion of the upper surface, the cloth sheet being attached to two or more side flaps extending laterally outward from the side edge of the cloth sheet near the side edge of the cloth sheet, each of the side flaps being configured to be attached to a mounting bracket or a side rail stand-off post or a side rail of the operating table at one or more attachment points, A patient fixation overlay in which the width of each side flap is greater than the distance between the attachment point and the cloth sheet to naturally create a preferred holding force vector angle of less than 45° between the attachment point and the cloth sheet.

Images