Abstract:
The invention pertains to positioning a patient in prone position, comprising:
       positioning a patient in a supine position,   attaching a chest body contact sheet to the chest of the patient with an attached inflatable chest cushion in the deflated state,   attaching a pelvic body contact sheet to the pelvic region of the patient with an attached inflatable pelvis cushion in the deflated state,   transferring the patient from the supine position to a prone position,   with the chest body contact sheet attached to the chest of the patient and the pelvic body contact sheet attached to the pelvic region of the patient and the patient in the prone position, inflating the chest cushion and the pelvis cushion, thereby making that the chest cushion and the pelvis cushion together bear the weight of the torso of the patient with the abdominal region of the patient being decompressed.       
 
     The invention is based on a combination of anatomy and physiology that is used for a reliable positioning the patient, which is safe for the patient and safe, hygienic and user friendly for the medical team.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is the National Stage of International Application No. PCT/IB2015/051979, filed 18 Mar. 2015, having the title “METHOD AND SYSTEM FOR POSITIONING A PATIENT” which claims the benefit of and priority to Netherlands Application No. 2012460, filed on 18 Mar. 2014, the contents of all of which are incorporated by reference as if fully set forth herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention pertains to a method for positioning a patient in a prone position on a patient support structure and a patient positioner system for positioning a patient in a prone position on a patient support structure, e.g. during spinal surgery. 
       BACKGROUND 
       [0003]    Many treatments, diagnostic methods or surgery on the neck or spine require a patient to be positioned in a prone position. In addition, some patients at an intensive care unit have to be ventilated in a prone position. Prone position means a face down position, and includes variants like the so called “jackknife position”, in which the torso and the legs extend downwardly at an angle from the hips. Often, such treatments or surgery require preparation of the patient while the patient lies in a supine position, that is: on his back, for example the intubation of a patient prior to an operation. 
         [0004]    It is known to position a patient on cushions on the patient support structure such as an operating table while the patient is undergoing treatment, diagnostics or surgery in a prone position. It is important that the patient is positioned well on the cushions during the operation. Improper positioning may cause a variety of health risks for the patient, for example due to increased intra abdominal pressure, compression of blood vessels, undue pressure on nerves, pressure or tension on the skin, pressure on the breasts of a female patient or—in case of a male patient—the genitals getting trapped. In particular when a patient is transferred into a prone position from a supine position, the position of the cushions relative to each other and the position of the patient on the cushions needs to be checked and often corrected in order to avoid such health risks for the patient. This is a physically demanding task for the medical team, which has to be carried out in an unfavorable ergonomic position, while standing next to and bending over the patient. Moreover, it is generally an unpleasant and unhygienic task. 
         [0005]    It is known to use inflatable cushions to support a patient while said patient is undergoing treatment, diagnostics or surgery in a prone position, for example from US2010/257674. 
         [0006]    Also WO2007/146059 discloses the use of inflatable cushions to support a patient, e.g. during surgery, in a prone position. The cushions of WO2007/146059 are arranged on a patient support, e.g. an operating table. When the patient is transferred laterally (e.g. from a bed onto the operating table) or transferred from a supine position to a prone position, the cushions may shift to an incorrect or otherwise undesired position relative to the patient or to the patient support. Correcting the position of the cushions relative to the patient or the patient support is physically very demanding for the medical team, because it requires lifting a heavy load while bending over the patient. This results in a high load on the back, in particular of the spine, of the person of the medical team that carries out the correction of the position of the cushions. This sometimes has to be done multiple times per day. 
         [0007]    The invention aims to provide an improved method for positioning a patient in a prone position on a patient support structure and a patient positioner system for positioning a patient in a prone position on a patient support structure. 
         [0008]    The invention provides a method for positioning a patient in a prone position on a patient support structure. 
         [0009]    A first step in the method is to provide a patient positioner system, which patient positioner system comprises a disposable chest positioner assembly and a disposable pelvis positioner assembly. 
         [0010]    The disposable chest positioner assembly comprises a chest body contact sheet and an inflatable chest cushion. 
         [0011]    The chest body contact sheet is made of a soft material, e.g. a material that is also used to make surgical drapes. The chest body contact sheet has a front surface and a rear surface. The chest body contact sheet is on the rear surface provided with an upper adhesive zone, which upper adhesive zone is adapted to be attached to the skin of a patient in the vicinity of the clavicle. The chest body contact sheet is on the rear surface further provided with a lower adhesive zone, which lower adhesive zone is adapted to be attached to the skin of a patient in the vicinity of the lower ribs. The upper adhesive zone is adapted to be attached to the skin of a patient in the vicinity of the clavicle can for example be reflected in the shape and/or position of the upper adhesive zone and in the type of adhesive that is used (e.g. skin-friendly adhesive). The lower adhesive zone is adapted to be attached to the skin of a patient in the vicinity of the lower ribs can for example be reflected in the shape and/or position of the lower adhesive zone, its distance to the upper adhesive zone and in the type of adhesive that is used (e.g. skin-friendly adhesive). 
         [0012]    The upper adhesive zone can for example be formed by an adhesive strip that is arranged in the upper part of the chest body contact sheet. Alternatively or in addition, the upper adhesive zone can for example be formed by a part of an adhesive strip that extends into the upper part of the chest body contact sheet. Likewise, lower adhesive zone can for example be formed by an adhesive strip that is arranged in the lower part of the chest body contact sheet. Alternatively or in addition, the lower adhesive zone can for example be formed by a part of an adhesive strip that extends into the lower part of the chest body contact sheet. The inflatable chest cushion is permanently attached to the front surface of the chest body contact sheet between the upper adhesive zone and the lower adhesive zone. The inflatable chest cushion has an deflated state and an inflated state. 
         [0013]    The disposable pelvis positioner assembly comprises a pelvic body contact sheet and an inflatable pelvis cushion. 
         [0014]    The pelvic body contact sheet is made of a soft material. The pelvic body contact sheet has a front surface and a rear surface. The pelvic body contact sheet is on the rear surface provided with an upper adhesive zone, which upper adhesive zone is adapted to be attached to the skin of a patient below but adjacent to the lower edge of the abdomen. The pelvic body contact sheet is on the rear surface further provided with a lower adhesive zone, which lower adhesive zone is adapted to be attached to the skin of a patient just above the inguinal region. The upper adhesive zone is adapted to be attached to the skin of a patient below but adjacent to the lower edge of the abdomen can for example be reflected in the shape and/or position of the upper adhesive zone and in the type of adhesive that is used (e.g. skin-friendly adhesive). The lower adhesive zone is adapted to be attached to the skin of a patient just above the inguinal region can for example be reflected in the shape and/or position of the lower adhesive zone, its distance to the upper adhesive zone and in the type of adhesive that is used (e.g. skin-friendly adhesive). 
         [0015]    The upper adhesive zone can for example be formed by an adhesive strip that is arranged in the upper part of the pelvic body contact sheet. Alternatively or in addition, the upper adhesive zone can for example be formed by a part of an adhesive strip that extends into the upper part of the pelvic body contact sheet. Likewise, lower adhesive zone can for example be formed by an adhesive strip that is arranged in the lower part of the pelvic body contact sheet. Alternatively or in addition, the lower adhesive zone can for example be formed by a part of an adhesive strip that extends into the lower part of the pelvic body contact sheet. The inflatable pelvis cushion is permanently attached to the front surface of the pelvic body contact sheet between the upper adhesive zone and the lower adhesive zone. The inflatable pelvis cushion has an deflated state and an inflated state. 
         [0016]    The next steps in the method according to the invention are:
       positioning a patient in a supine position on the patient support structure, for example a bed or table,   attaching the chest body contact sheet of the disposable chest positioner assembly to the chest of the patient by attaching the upper adhesive zone of the chest body contact sheet to the skin of a patient in the vicinity of the clavicle of the patient and attaching the lower adhesive zone of the chest body contact sheet to the skin of a patient in the vicinity of the lower ribs of the patient, with the inflatable chest cushion of the disposable chest positioner assembly in the deflated state,   attaching the pelvic body contact sheet of the disposable pelvis positioner assembly to the pelvic region of the patient by attaching the upper adhesive zone of the pelvic body contact sheet to the skin of a patient just below the abdominal region of the patient and attaching the lower adhesive zone of the pelvic body contact sheet to the skin of a patient just above the inguinal region of the patient, with the inflatable pelvis cushion of the disposable pelvis positioner assembly in the deflated state,   transferring the patient from the supine position to a prone position, thereby making the patient come to lie on the patient support structure in a prone position,   with the chest body contact sheet attached to the chest of the patient and the pelvic body contact sheet attached to the pelvic region of the patient and the patient in the prone position, inflating the chest cushion and the pelvis cushion, thereby lifting the patient from the patient support structure by making that the chest cushion and the pelvis cushion together bear the weight of the torso of the patient while the patient is in a prone position with the abdominal region of the patient being decompressed.       
 
         [0022]    The chest cushion and the pelvis cushion can be inflated simultaneously or subsequently (one after the other). 
         [0023]    Generally, the inflated chest cushion and the inflated pelvis cushion together bear more than 50% of the weight of the patient. Optionally, the inflated chest cushion and the inflated pelvis cushion together bear more than 75% of the weight of the patient. 
         [0024]    The invention further provides a patient positioner system for positioning a patient in a prone position on a patient support structure, which patient positioner system comprises a disposable chest positioner assembly and a disposable pelvis positioner assembly. 
         [0025]    The chest positioner assembly comprises a chest body contact sheet and an inflatable chest cushion. 
         [0026]    The chest body contact sheet is made of a soft material. The chest body contact sheet has a front surface and a rear surface. The chest body contact sheet is on the rear surface provided with an upper adhesive zone, which upper adhesive zone is adapted to be attached to the skin of a patient in the vicinity of the clavicle. The chest body contact sheet is on the rear surface further provided with a lower adhesive zone, which lower adhesive zone is adapted to be attached to the skin of a patient in the vicinity of the lower ribs. 
         [0027]    That the upper adhesive zone is adapted to be attached to the skin of a patient in the vicinity of the clavicle can for example be reflected in the shape and/or position of the upper adhesive zone and in the type of adhesive that is used (e.g. skin-friendly adhesive). That the lower adhesive zone is adapted to be attached to the skin of a patient in the vicinity of the lower ribs can for example be reflected in the shape and/or position of the lower adhesive zone, its distance to the upper adhesive zone and in the type of adhesive that is used (e.g. skin-friendly adhesive). 
         [0028]    The inflatable chest cushion is permanently attached to the front surface of the chest body contact sheet between the upper adhesive zone and the lower adhesive zone. The inflatable chest cushion has an deflated state and an inflated state. In the patient positioner system according to the invention, the inflatable chest cushion—when the disposable chest positioner assembly is attached to a patient—in its inflated state has a shape that leaves the abdominal region of the patient decompressed. 
         [0029]    The disposable pelvis positioner assembly comprises a pelvic body contact sheet and an inflatable pelvis cushion. 
         [0030]    The pelvic body contact sheet is made of a soft material. The pelvic body contact sheet has a front surface and a rear surface. The pelvic body contact sheet is on the rear surface provided with an upper adhesive zone, which upper adhesive zone is adapted to be attached to the skin of a patient below but adjacent to the lower edge of the abdomen. The pelvic body contact sheet is on the rear surface further provided with a lower adhesive zone, which lower adhesive zone is adapted to be attached to the skin of a patient just above the inguinal region. 
         [0031]    That the upper adhesive zone is adapted to be attached to the skin of a patient below but adjacent to the lower edge of the abdomen can for example be reflected in the shape and/or position of the upper adhesive zone and in the type of adhesive that is used (e.g. skin-friendly adhesive). That the lower adhesive zone is adapted to be attached to the skin of a patient just above the inguinal region can for example be reflected in the shape and/or position of the lower adhesive zone, its distance to the upper adhesive zone and in the type of adhesive that is used (e.g. skin-friendly adhesive). 
         [0032]    The inflatable pelvis cushion is permanently attached to the front surface of the pelvic body contact sheet between the upper adhesive zone and the lower adhesive zone. The inflatable pelvis cushion has an deflated state and an inflated state. In the patient positioner system according to the invention, the inflatable pelvis cushion—when the disposable pelvis positioner assembly is attached to a patient—in its inflated state has a shape that leaves the abdominal region of the patient decompressed, 
         [0033]    In the patient positioner system according to the invention, the inflatable chest cushion and the inflatable pelvis cushion are adapted to in their inflated state together support the torso of the patient on the patient support structure while leaving the abdominal region of the patient decompressed. Generally, the inflated chest cushion and the inflated pelvis cushion together bear more than 50% of the weight of the patient. Optionally, the inflated chest cushion and the inflated pelvis cushion together bear more than 75% of the weight of the patient. 
         [0034]    In a possible embodiment, the chest cushion comprises a rear wall, and in the inflated state, the rear wall of the chest cushion has a neck side edge and an abdominal side edge. This neck side edge and this abdominal side edge have a concave (i.e. hollow) shape having a radius of curvature. The radius of curvature of the neck side edge of the rear wall is larger than the radius of curvature of the abdominal side edge of the rear wall. 
         [0035]    In this embodiment, optionally the rear wall the chest cushion is wider at its neck side edge than at its abdominal side edge. 
         [0036]    In this embodiment, optionally the distance between the neck side edge and the abdominal side edge of the rear wall at the center of the chest cushion is substantially equal to the length of a human breast bone. “Substantially equal to the length of a human breast bone” means that this distance not more than 150 millimeter longer and no more than 150 millimeter shorter than the normal length of a human breastbone. In practical embodiments, this distance is for example between 200 millimeter and 375 millimeter, preferably between 250 millimeter and 375 millimeter or between 200 millimeter and 300 millimeter. 
         [0037]    In this embodiment, optionally the chest cushion further comprises a front wall, wherein in the inflated state, the front wall of the chest cushion has a neck side edge and an abdominal side edge, wherein said neck side edge and abdominal side edge have a concave shape having a radius of curvature, wherein the radius of curvature of the neck side edge of the front wall is larger than the radius of curvature of the abdominal side edge of the front wall, and wherein the distance between the neck side edge and the abdominal side edge of the front wall at the center of the chest cushion is substantially equal to the length of a human breast bone, wherein optionally the front wall of the chest cushion is wider at its neck side edge than at its abdominal side edge. 
         [0038]    In a possible embodiment, the pelvis cushion comprises a rear wall, and in the inflated state, the rear wall of the pelvis cushion has an abdominal side edge and a genital side edge. This abdominal side edge and genital side edge have a concave (i.e. hollow) shape having a radius of curvature. The radius of curvature of the abdominal side edge of the rear wall is larger than the radius of curvature of the genital side edge of the rear wall. 
         [0039]    Optionally, in this embodiment, the distance between the abdominal side edge and the genital side edge of the rear wall at the center of the pelvis cushion is substantially equal to the distance between the lower edge of the abdomen and the upper edge of the exterior genitals in a human. “Substantially equal to the distance between the lower edge of the abdomen and the upper edge of the exterior genitals in a human” means that this distance not more than 100 millimeter longer and no more than 100 millimeter shorter than the normal length of this distance. In practical embodiments, this distance is for example between 50 millimeter and 250 millimeter, preferably between 100 millimeter and 200 millimeter. 
         [0040]    In this embodiment, optionally the pelvis cushion further comprises a front wall, wherein in the inflated state, the front wall of the pelvis cushion has an abdominal side edge and a genital side edge, wherein said abdominal side edge and genital side edge have a concave shape having a radius of curvature, wherein the radius of curvature of the abdominal side edge of the front wall is larger than the radius of curvature of the genital side edge of the front wall, and wherein the distance between the abdominal side edge and the genital side edge of the front wall at the center of the pelvis cushion is substantially equal to the distance between the lower edge of the abdomen and the upper edge of the exterior genitals in a human. 
         [0041]    In a possible embodiment, the rear surface of the chest body contact sheet forms part of the outer surface of the inflatable chest cushion. 
         [0042]    In a possible embodiments, the rear surface of the pelvic body contact sheet forms part of the outer surface of the inflatable pelvis cushion. 
         [0043]    In a different embodiment of the general inventive idea, the invention provides a disposable patient positioner system for positioning a patient in a prone position on a patient support structure, 
         [0044]    which disposable patient positioner system comprises:
       a disposable chest positioner assembly, which disposable chest positioner assembly comprises a disposable inflatable chest cushion, which chest cushion comprises a rear wall,       
 
         [0046]    wherein the rear wall of the chest cushion comprises a chest body contact sheet which is made of a soft material, which chest body contact sheet has a rear surface which forms part of the outer surface of the chest cushion, 
         [0047]    which chest body contact sheet is on the rear surface provided with at least one adhesive zone, which adhesive zone is adapted to be attached to the skin of a patient in the chest area, 
         [0048]    wherein the disposable inflatable chest cushion has a deflated state and an inflated state, 
         [0049]    wherein in the inflated state, the rear wall of the chest cushion has a neck side edge and an abdominal side edge, wherein said neck side edge and abdominal side edge have a concave shape having a radius of curvature, wherein the radius of curvature of the neck side edge of the rear wall is larger than the radius of curvature of the abdominal side edge of the rear wall, 
         [0050]    and wherein the distance between the neck side edge and the abdominal side edge of the rear wall at the center of the chest cushion is substantially equal to the length of a human breast bone, and
       a disposable pelvis positioner assembly, which disposable pelvis positioner assembly comprises a disposable inflatable pelvis cushion,       
 
         [0052]    which pelvis cushion comprises a rear wall, 
         [0053]    wherein the rear wall of the pelvis cushion comprises a pelvic body contact sheet which is made of a soft material, which pelvic body contact sheet has a rear surface which forms part of the outer surface of the pelvis cushion, 
         [0054]    which pelvic body contact sheet is on the rear surface provided with at least one adhesive zone, which adhesive zone is adapted to be attached to the skin of a patient in the pelvis area, 
         [0055]    wherein the disposable inflatable pelvis cushion has a deflated state and an inflated state, 
         [0056]    wherein in the inflated state, the rear wall of the pelvis cushion has an abdominal side edge and a genital side edge, wherein said abdominal side edge and genital side edge have a concave shape having a radius of curvature, wherein the radius of curvature of the abdominal side edge of the rear wall is larger than the radius of curvature of the genital side edge of the rear wall, 
         [0057]    and wherein the distance between the abdominal side edge and the genital side edge of the rear wall at the center of the pelvis cushion is substantially equal to the distance between the lower edge of the abdomen and the upper edge of the exterior genitals in a human, 
         [0058]    wherein the inflatable chest cushion and the inflatable pelvis cushion are adapted to in their inflated state together support the torso of the patient on the patient support structure and wherein the shape of the inflatable chest cushion and the inflatable pelvis cushion in their inflated state allows to leave the abdominal region of the patient decompressed. 
         [0059]    “Substantially equal to the length of a human breast bone” means that this distance not more than 150 millimeter longer and no more than 150 millimeter shorter than the normal length of a human breastbone. In practical embodiments, this distance is for example between 200 millimeter and 375 millimeter, preferably between 250 millimeter and 375 millimeter or between 200 millimeter and 300 millimeter. 
         [0060]    “Substantially equal to the distance between the lower edge of the abdomen and the upper edge of the exterior genitals in a human” means that this distance not more than 100 millimeter longer and no more than 100 millimeter shorter than the normal length of this distance. In practical embodiments, this distance is for example between 50 millimeter and 250 millimeter, preferably between 100 millimeter and 200 millimeter. 
         [0061]    In both main variants of the general inventive idea and their respective embodiments, the abdominal region of the patient is kept decompressed when the patient is in the prone position. So, compression of the abdominal region is avoided when the patient is in the prone position. 
         [0062]    Keeping the abdominal region of the patient decompressed implies that the inflatable chest cushion and the inflatable pelvis cushion do not engage the patient in the abdominal region. This is not only comfortable for the patient, but also particularly advantageous during spinal surgery as it prevents excessive bleeding. Such excessive bleeding may occur due to increased intra-abdominal venous pressure when the patient is supported in such a way that the abdominal region bears part of the weight of the torso. 
         [0063]    In case of such an increase of the abdominal pressure, venous blood is pushed through the valveless plexus of Batson into the vertebral venous system. This a because there is a free communication via a valveless system between the veins throughout the vertebral canal with those of the chest, abdomen and pelvis through the intercostal, lumbar and other connecting veins. 
         [0064]    Reducing the intra-abdominal pressure or preventing an undesired increase in intra-abdominal pressure is also important in cases of prone ventilation. Prone ventilation is often used in the ICU (intensive care unit) in cases of acute respiratory failure. Prone ventilation ameliorates the underlying physical strain and generation of inflammatory mediators that compound ventilator induced lung injury. The presence of atelectasis and lung recruitability is the most important reason for the prone ventilation. In these cases exact positioning of the thoracopelvic supports are important for three reasons: to redistribute ventilatory gasses towards the now dependent ventral and diaphragmatic regions where atelectasis and collapse are present; to avoid compressing a noncompliant distended abdomen, especially if intra-abdominal hypertension (IAH) is present; and to potentially unload an abdomen of the lungs with sufficient abdominal compliance to allow this. 
         [0065]    The method and patient positioner systems in accordance with the invention use a combination of anatomy and physiology to provide a reliable way of positioning the patient during treatment, diagnostics and/or surgery, which is safe for the patient as well as safe, hygienic and user friendly for the medical team. 
         [0066]    The chest positioner assembly and the pelvis positioner assembly in principle are separate items. This makes it easier to handle and to attach them to a patient. Furthermore, this makes that the chest positioner assembly and the pelvis positioner assembly can be positioned accurately regardless of the length of the patient. In a possible embodiment, there may be a connection between chest positioner assembly and the pelvis positioner assembly, e.g. by a cord, but in general this will not be desired. 
         [0067]    In accordance with the method and systems according to the invention, the chest positioner assembly and the pelvis positioner assembly are both disposable. They are intended for single use. This provides a more hygienic solution that the cushions that are known in the art, as the known cushions are re-used multiple times. The known cushions have to be cleaned for each subsequent patient, or a disposable sheet has to be provided on the known cushions. Such a sheet is often slippery and causes problems with the positioning of the patient, for example because the sheet shifts over the cushions when the patient is positioned. Furthermore, creases can occur that cause local high pressure on the body of the patient, which could result in lesions for the patient. 
         [0068]    By attaching the disposable chest positioner assembly and the disposable pelvis positioner assembly according to the invention to the patient by the provided adhesive zones, a proper positioning of the disposable chest positioner assembly and the disposable pelvis positioner assembly relative to the patient remains ensured even after transferring the patient from a supine position to a prone position. This makes that the disposable chest positioner assembly and the disposable pelvis positioner assembly can be applied to the patient while the patient is in de the supine position. This is easier for the medical staff. Furthermore, it allows a more accurate positioning, as anatomical landmarks of the patient can be used for an accurate positioning of the disposable chest positioner assembly and the disposable pelvis positioner assembly. Examples of such anatomical landmarks are the clavicle, breastbone and or lower ribs for the chest positioner assembly and the lower edge of the abdomen and inguinal region for the pelvis positioner assembly. 
         [0069]    The chest body contact sheet and the pelvic body contact sheet are made of a soft material, e.g. a textile or non-woven material of natural or synthetic fibers. These and similar materials are flexible and can form themselves at least generally to the shape of the body of the patient. Preferably, they have a pleasant touch and feel to the skin of the patient. 
         [0070]    Preferably, one or more adhesive zones are provided for attachment of the disposable chest positioner assembly or the disposable pelvis positioner assembly, respectively, to these anatomical landmarks. Optionally, adhesive zones are provided on the rear surface of the chest body contact sheet or the pelvic body contact sheet, respectively, that generally match the shape and size of at least one of these anatomical landmarks as seen from the ventral side. 
         [0071]    Optionally, the adhesive zone, optionally the upper adhesive zone of the disposable chest positioner assembly generally matches the shape and size of the clavicle as seen from the ventral side, and/or the adhesive zone, optionally the lower adhesive zone of the disposable chest positioner assembly generally matches the shape and size of the lower ribs as seen from the ventral side. Optionally, an additional adhesive zone provided on the rear of the chest body contact sheet of the disposable chest positioner assembly that generally matches the shape and size of the breastbone as seen from the ventral side. Of course, the distance between those adhesive zones and their relative position generally matches the distance between the clavicle, lower ribs and breastbone and their relative position. 
         [0072]    Optionally, the adhesive zone, optionally the upper adhesive zone of the disposable pelvis positioner assembly generally matches the shape and size of the lower edge of the abdomen as seen from the ventral side, and/or the adhesive zone, optionally the lower adhesive zone of the disposable pelvis positioner assembly generally matches the shape and size of the inguinal region as seen from the ventral side. Of course, the distance between those adhesive zones and their relative position generally matches the distance between the lower edge of the abdomen and the inguinal region, and their relative position. 
         [0073]    By inflating the chest cushion and the pelvis cushion after the patient has been transferred into the prone position, the patient is automatically positioned by the chest cushion and the pelvis cushion. This can easily be done by a single person and does not require physical force. 
         [0074]    The method according to the invention and/or the use of the patient positioner system according to the invention make it possible to carry out treatments, diagnostic methods and/or surgery on a properly positioned patient lying in prone position, without having to use a dedicated patient support structure that is specifically adapted for supporting patients in prone position. For example, it is no longer necessary to use a spine table when performing spinal surgery. 
         [0075]    For some treatments, diagnostic methods or operations, it is desired or necessary that the patient is positioned in a jackknife position. In such a position, the patient lies face down, with the hips at a level above the head and above the legs. This causes a larger opening of interlaminar window of the lumbar spine and can provide an easier access to the spinal canal for surgery. 
         [0076]    In a possible embodiment of the invention, the pelvis cushion of the disposable pelvis positioner assembly in the inflated state is thicker than the chest cushion of the disposable chest positioner assembly in the inflated state. In this embodiment, the patient can be positioned in a jackknife position without the use of a specially adapted surgery table. 
         [0077]    For some treatments, diagnostic methods or operations, it is desired or necessary that the patient is positioned with hyperflexion of the cervical spine. In this position, the head is bent forward such that the chin of the patient touches or almost touches the chest. This way, the back of the neck of the patient flexes to a large extend. This is necessary in case of surgery on the cervical spine via a posterior approach as in a cervical laminectomy procedure. This position is also needed in posterior fossa approaches in cranial neurosurgery 
         [0078]    In a possible embodiment of the invention, the chest cushion has in its inflated state a shape that leaves the clavicle and manubrium sterni free or at least does not extend beyond the clavicle and manubrium sterni. Optionally, in this embodiment, the upper adhesive zone and/or the upper edge of the chest body contact sheet has a shape that generally matches the shape and size of the clavicle and manubrium sterni In this embodiment, it is possible to position a patient in hyperflexion of the cervical spine. 
         [0079]    The chest cushion and the pelvis cushion can be inflated using compressed air, which is generally available in e.g. operating rooms. However, in a possible embodiment, the patient positioner system according to the invention further comprises a pump that is connectable to the inflatable chest cushion and to the inflatable pelvis cushion, either subsequently or at the same time, to inflate said cushions. 
         [0080]    In an advantageous embodiment of the method, at least one of the supraclavicular region, the lateral cutaneous nerve, the vena saphena magna, the arterie femoralis, the breasts (in case of a female patient) and/or the genital region of the patient is decompressed while the patient is in the prone position with the inflated pelvis cushion and the inflated chest cushion bearing the weight of the torso of said patient. 
         [0081]    Likewise, in an advantageous embodiment of the system according to the invention, the inflatable pelvis cushion—when attached to a patient—in its inflated state has a shape that leaves the lateral cutaneous nerve, the vena saphena magna, the arterie femoralis and/or the genital region of the patient decompressed, and/or the inflatable chest cushion—when attached to a patient—in its inflated state has a shape that leaves supraclavicular region of the patient decompressed. 
         [0082]    Leaving the supraclavicular region decompressed when the patient in in the prone position and the chest cushion and pelvis cushion carry the weight of the torso of the patient helps the patient to be ventilated easily and prevents compression of the blood vessels to and from the head. Furthermore, it makes hyperflexion of the cervical spine possible which is needed in some procedures. 
         [0083]    Leaving the lateral cutaneous nerve in the thigh decompressed when the patient in in the prone position and the chest cushion and pelvis cushion carry the weight of the torso of the patient prevents meralgia paresthetica, which can occur due to sustained pressure on the lateral cutaneous nerve in the thigh. 
         [0084]    Leaving the vena saphena magna and/or the arterie femoralis decompressed when the patient in in the prone position and the chest cushion and pelvis cushion carry the weight of the torso of the patient allows the inguinal region to be used for catheterization and prevents compression of the blood vessels. 
         [0085]    Leaving the genital region decompressed when the patient in in the prone position and the chest cushion and pelvis cushion carry the weight of the torso of the patient, prevents damage to the genitalia of male patients, and makes it no longer necessary for the medical staff to check with the hand whether the male genitalia are in the correct position under the body of the patient. This is often regarded as an unpleasant task, which is also unhygienic. 
         [0086]    Leaving the breasts (in case of a female patient) decompressed when the patient in in the prone position and the chest cushion and pelvis cushion carry the weight of the torso of the patient, prevents undue compression of the breasts. 
         [0087]    In a possible embodiment of the system according to the invention, the chest body contact sheet of the disposable chest positioner assembly is on the rear surface further provided with a central adhesive zone. This central adhesive zone optionally as a shape that generally corresponds to the shape of a human breastbone or a part thereof as seen from the ventral side. The central adhesive zone is adapted to be attached to the skin of a patient in the vicinity of the breastbone. 
         [0088]    When using a chest positioner assembly with such a central adhesive zone (for example in the method according to the invention), optionally this chest positioner assembly is attached to the patient by first attaching the central adhesive zone to the patient, preferably in the vicinity of the breast bone of the patient and then attaching the other adhesive zones to the patient. 
         [0089]    In a possible embodiment of the method and/or system of the invention, the chest body contact sheet is further provided with a left adhesive zone and a right adhesive zone, so that the chest body contact sheet is attached to the patient&#39;s chest on four sides. 
         [0090]    In a possible embodiment of the method and/or system of the invention, the pelvic body contact sheet is further provided with a left adhesive zone and a right adhesive zone, so that the pelvic body contact sheet is attached to the patient&#39;s pelvic region on four sides. 
         [0091]    In a possible embodiment of the method and/or system of the invention, the chest body contact sheet is provided with an adhesive area, into which at least one adhesive zone is integrated. For example, in such an embodiment, an adhesive area is provided in the shape of a rectangle (optionally a rectangle with an open center), which rectangle includes the upper adhesive zone, the lower adhesive zone and optionally a left adhesive zone and a right adhesive zone. 
         [0092]    In a possible embodiment of the method and/or system of the invention, the pelvic body contact sheet is provided with an adhesive area, into which at least one adhesive zone is integrated. For example, in such an embodiment, an adhesive area is provided in the shape of a rectangle (optionally a rectangle with an open center), which rectangle includes the upper adhesive zone, the lower adhesive zone and optionally a left adhesive zone and a right adhesive zone. 
         [0093]    In a possible embodiment, the chest cushion and/or the pelvis cushion comprises multiple air chambers. 
         [0094]    In a possible embodiment, the at least a part of the wall of the chest cushion is formed by at least a part of the chest body contact sheet. 
         [0095]    In a possible embodiment, the at least a part of the wall of the pelvis cushion is formed by at least a part of the pelvic body contact sheet. 
         [0096]    In a possible embodiment, the pelvic body contact sheet comprises a non-inflatable genital region covering flap. This non-inflatable genital region covering flap has a shape that—when the disposable pelvis positioner assembly is attached to a patient—extends over the genital region of the patient. The genital region covering flap prevents the male genitalia from getting trapped or otherwise coming to lie in an unfavorable or harmful position after the patient has been transferred from a supine position into a prone position. This further eliminates the need for the medical staff to check with the hand whether the male genitalia are in the correct position under the body of the patient. 
         [0097]    In embodiments in which the pelvic body contact sheet forms part of the wall, e.g. part of the rear wall of the pelvis cushion, the non-inflatable genital region covering flap extends beyond the walls of the pelvis cushion. So, in these embodiments not the entire pelvic body contact sheet forms part of the wall of the pelvis cushion. In these embodiments, the pelvic body contact sheet comprises a first region which forms part of the wall, e.g. of the rear wall, of the pelvis cushion, and a second region which forms the non-inflatable genital region covering flap. 
         [0098]    In a variant, the non-inflatable genital region covering flap is connected to the front of the pelvis cushion instead of to the rear of the pelvis cushion. 
         [0099]    The genital region covering flap can further prevent that a urinary catheter gets folded or otherwise jammed under the patient while the patient is in or is moved into a prone position. For example, but not necessarily, the genital region covering flap may comprises a loop or other attachment means for attaching a urinary catheter to it. 
         [0100]    Optionally, the non-inflatable genital region covering flap is provided with an attachment member that is adapted to attach the genital region covering flap to the upper leg of a patient. Such an attachment member can for example be a simple cord or string, optionally provided with Velcro, to loosely attach the genital region covering flap to the upper leg of the patient. This generally is preferable to sticking the genital region covering flap to the upper leg of the patient, as the loose attachment gives the patient some freedom of movement. 
         [0101]    In a possible embodiment, the chest body contact sheet comprises a pocket or fold, which pocket of fold is adapted in its shape, size and position on the body contact sheet to accommodate at least one breast of a female patient when the disposable chest positioner assembly is attached to said female patient. Preferably in this embodiment, either two pockets or folds are present, each adapted for accommodating a single breast of a female patient, or otherwise, one pocket or fold is present that is adapted to accommodate both breasts of the female patient. 
         [0102]    In a variant of this embodiment, the rear wall of the inflatable chest cushion comprises the chest body contact sheet, which in this variant comprises a pocket or fold, which pocket of fold is adapted in its shape, size and position on the chest body contact sheet to accommodate at least one breast of a female patient when the disposable chest positioner assembly is attached to said female patient. In this variant, the rear wall of chest cushion in its inflated stated has a recess to accommodate at least one breast of a female patient. In practical embodiments, there will generally be either one recess in which both breasts can be accommodated or two recesses in each of which a single breast can be accommodated. 
         [0103]    In a possible embodiment, the inflatable chest cushion in its inflated state projects between 5 cm and 25 cm from the front surface of the chest body contact sheet. Optionally, the inflatable chest cushion in its inflated state projects between 10 cm and 20 cm from the front surface of the chest body contact sheet. 
         [0104]    In a possible embodiment, the inflatable pelvis cushion in its inflated state projects between 5 cm and 25 cm from the front surface of the pelvic body contact sheet. Optionally, the inflatable pelvis cushion in its inflated state projects between 10 cm and 20 cm from the front surface of the pelvic body contact sheet. 
         [0105]    In a possible embodiment of the invention, the pelvis cushion of the disposable pelvis positioner assembly in the inflated state is thicker than the chest cushion of the disposable chest positioner assembly in the inflated state. For example, the inflatable chest cushion in its inflated state projects between 5 cm and 10 cm from the front surface of the chest body contact sheet and the inflatable pelvis cushion in its inflated state projects between 20 cm and 25 cm from the front surface of the pelvic body contact sheet. This allows to position the patient in a jackknife position without using a specially adapted surgery table. 
         [0106]    In a possible embodiment, the chest cushion and/or the pelvis cushion has a non-symmetric shape in the inflated state. For example, the chest cushion may in its inflated state project further from the front surface of the chest body contact sheet in the vicinity of the lower ribs than in the vicinity of the clavicle, or the other way around. Furthermore, for example, the pelvis cushion may in its inflated state project further from the front surface of the pelvic body contact sheet in the vicinity of the lower edge of the abdomen than in the vicinity of the inguinal region, or the other way around. 
         [0107]    In a possible embodiment, the chest cushion is provided with an air supply connector or a flexible air hose, wherein the air supply connector or flexible air hose is connected to the chest cushion at an air supply location at the chest cushion. The air supply location is located on a lateral side of the chest cushion in the inflated state, so that the patient does not lie on a hard part in the chest cushion. The lateral side of the chest cushion can for example be the peripheral wall of the chest cushion that is generally perpendicular to the patient in the inflated state of the chest cushion. Preferably, the air supply hose it at least 30 cm long, preferably at least 50 cm long. 
         [0108]    In a possible embodiment, the pelvis cushion is provided with an air supply connector or a flexible air hose, wherein the air supply connector or flexible air hose is connected to the pelvis cushion at an air supply location at the pelvis cushion. The air supply location is located on a lateral side of the pelvis cushion in the inflated state, so that the patient does not lie on a hard part in the chest cushion. The lateral side of the chest cushion can for example be the peripheral wall of the pelvis cushion that is generally perpendicular to the patient in the inflated state of the pelvis cushion. Preferably, the air supply hose it at least 30 cm long, preferably at least 50 cm long. 
         [0109]    In a possible embodiment, the chest cushion and/or the pelvis cushion is provided with a check valve in order to prevent undesired deflation of the cushion. 
         [0110]    In a possible embodiment, the chest cushion and/or the pelvis cushion is provided with a pressure relief valve, optionally a manually operable pressure relieve valve. The pressure relief valve allows the a person of the medical team, e.g. the surgeon, to reduce the pressure in the cushion in case the pressure in the chest cushion and/or the pelvis cushion has become higher than desired, e.g. from the viewpoint of comfort for the patient. Optionally, in case of manually operable pressure relief valve, the pressure relief valve requires the use of two hands for actuation. This prevents on unintentional pressure release of the inflatable chest cushion and/or pelvis cushion, respectively. 
         [0111]    In a possible embodiment, the chest cushion and/or the pelvis cushion is provided with a safety relief valve to prevent an unsafe pressure in the chest cushion and/or pelvis cushion, respectively. 
         [0112]    In a possible embodiment, the chest cushion and/or the pelvis cushion is provided with a valve assembly which comprises at least two of a check valve, a pressure relief valve and a safety relief valve. Optionally, these valves are arranged in a common valve housing. 
         [0113]    Optionally, the chest cushion and/or the pelvis cushion is provided with a valve assembly which comprises a check valve, a pressure relief valve and a safety relief valve, with the check valve, pressure relief valve and safety relief valve being arranged in are arranged in a common valve housing. Optionally, the pressure relief valve in this embodiment is a manually operable pressure relief valve, which requires the use of two hands for actuation. 
         [0114]    This type of valve assembly can also be used in combination with other inflatable cushions for patient support, resulting a an inflatable cushion for patient positioning during diagnosis, treatment or surgery, which cushion is provided with a valve assembly which comprises a check valve, a pressure relief valve and a safety relief valve, with the check valve, pressure relief valve and safety relief valve being arranged in are arranged in a common valve housing, and wherein optionally, the pressure relief valve is a manually operable pressure relief valve which requires the use of two hands for actuation. 
         [0115]    Optionally, regardless of whether the valve assembly is use din combination with an inflatable cushion of a patient positioner according to the invention or with an other type of inflatable cushion for patient support, the common valve housing has a length (seen in the direction of normal flow of pressure medium, e.g. air, through the valve) of less than 10 centimeter, optionally less than 5 centimeter. 
         [0116]    The inflated chest cushion and the inflated chest cushion bear a significant amount of the weight of the patient. Therefore, the use of a check valve, pressure relief valve and/or safety relief valve (either as separate items or combined in a valve assembly) is advantageous, as it increases the safety and optionally also the comfort of the patient. The check valve prevents undesired return of pressurized air of other pressurizing medium from the cushion to the source of pressurized medium, therewith preventing undesired deflation of the cushion. The safety relief valve prevents that the pressure in the cushion becomes too high from a safety point of view. The pressure relief valve allows to reduce the pressure in the inflated cushion as desired by the medical team, e.g. to increase the comfort of the patient or to obtain a suitable working height of for the medical team. 
         [0117]    It is not necessary that a check valve, pressure relief valve and/or safety relief valve are provided as part of the patient positioner according to the invention. It is for example also possible that one or more of such valves or valves having similar functions are provided in the room where the patient positioner according to the invention is used, e.g. as part of a central pressurized air supply system of the hospital. 
         [0118]    In a possible embodiment, the patient positioner according to the invention further comprises a pressure sensing device which is adapted to measure and/or monitor the pressure in the chest cushion and/or in the pelvis cushion. 
         [0119]    The pressure sensing device can for example comprise a pressure sensor which is arranged in or connected to the chest cushion and/or to the pelvis cushion. The pressure sensor measures the pressure in the chest cushion and/or in the pelvis cushion, respectively. Optionally, the pressure sensor is connectable to an external monitoring device, which is adapted to monitor one or more parameters of the patient and/or of the medical devices in use. 
         [0120]    Optionally, the pressure sensing device also comprises a alarm device, which is adapted to trigger an alarm when the pressure in a cushion has become either too high or too low. This alarm then alerts the medical team, e.g. the medical team of an intensive care unit, to correct the pressure in the cushion. An advantage of the alarm device is that the pressure in the cushion or cushions does not need to be constantly or periodically be monitored by e.g. staff of the intensive care unit. They only will have to take action to correct the pressure when the alarm has been triggered by the alarm device. 
         [0121]    Optionally, the pressure sensing device further comprises a pressure controller, which is adapted to control the pressure in the chest cushion and/or in the pelvis cushion. 
         [0122]    An embodiment with a pressure sensing device is in particular advantageous for use in an intensive care unit, because in an intensive care unit the patient positioner according to the invention will generally be used for a longer period of time than e.g. during surgery. 
         [0123]    In a possible embodiment, the rear wall of the chest cushion and/or the chest body contact sheet has a hollow shape. Optionally, this hollow shape substantially follows the generally convex shape of a human chest. 
         [0124]    In a possible embodiment, the invention pertains to a patient positioner system in accordance with claim  4  which is arranged in a packaging, wherein the packaging comprises and/or contains instructions to:
       attach the chest body contact sheet of the disposable chest positioner assembly to the chest of the patient by attaching the upper adhesive zone of the chest body contact sheet to the skin of a patient in the vicinity of the clavicle of the patient and attaching the lower adhesive zone of the chest body contact sheet to the skin of a patient in the vicinity of the lower ribs of the patient, and   attach the pelvic body contact sheet of the disposable pelvis positioner assembly to the pelvic region of the patient by attaching the upper adhesive zone of the pelvic body contact sheet to the skin of a patient just below the abdominal region of the patient and attaching the lower adhesive zone of the pelvic body contact sheet to the skin of a patient just above the inguinal region of the patient, and   transfer the patient from the supine position to a prone position, and   with the chest body contact sheet attached to the chest of the patient and the pelvic body contact sheet attached to the pelvic region of the patient and the patient in the prone position, to inflate the chest cushion and the pelvis cushion.       
 
         [0129]    In a possible embodiment, the invention pertains to a patient positioner system in accordance with claim  5  which is arranged in a packaging, wherein the packaging comprises and/or contains instructions to:
       attach the chest body contact sheet of the disposable chest positioner assembly to the chest of the patient by attaching the adhesive zone of the chest body contact sheet to the skin of the patient in the chest area, leaving the abdominal region free, and   attach the pelvic body contact sheet of the disposable pelvis positioner assembly to the pelvic region of the patient by attaching the adhesive zone of the pelvic body contact sheet to the skin of the patient in the pelvic region, leaving the abdominal region free, and   transfer the patient from the supine position to a prone position, and   with the chest body contact sheet attached to the chest of the patient and the pelvic body contact sheet attached to the pelvic region of the patient and the patient in the prone position, to inflate the chest cushion and the pelvis cushion.       
 
         [0134]    The invention further pertains to a patient positioner system according to any of the claims  4 - 25  for use in positioning a patient in a prone position, preferably for positioning a patient in a prone position for spinal surgery. 
         [0135]    The invention further pertains to a method for positioning a patient in a prone position on a patient support structure, which method comprises the following steps:
       providing a patient positioner system according to any of the claims  4 - 13 ,   positioning a patient in a supine position on the patient support structure,   attaching the chest body contact sheet of the disposable chest positioner assembly to the chest of the patient by attaching the upper adhesive zone of the chest body contact sheet to the skin of a patient in the vicinity of the clavicle of the patient and attaching the lower adhesive zone of the chest body contact sheet to the skin of a patient in the vicinity of the lower ribs of the patient, with the inflatable chest cushion of the disposable chest positioner assembly in the deflated state,   attaching the pelvic body contact sheet of the disposable pelvis positioner assembly to the pelvic region of the patient by attaching the upper adhesive zone of the pelvic body contact sheet to the skin of a patient just below the abdominal region of the patient and attaching the lower adhesive zone of the pelvic body contact sheet to the skin of a patient just above the inguinal region of the patient, with the inflatable pelvis cushion of the disposable pelvis positioner assembly in the deflated state,   transferring the patient from the supine position to a prone position, thereby making the patient come to lie on the patient support structure in a prone position,   with the chest body contact sheet attached to the chest of the patient and the pelvic body contact sheet attached to the pelvic region of the patient and the patient in the prone position, inflating the chest cushion and the pelvis cushion, thereby lifting the patient from the patient support structure by making that the chest cushion and the pelvis cushion together bear the weight of the torso of the patient while the patient is in a prone position with the abdominal region of the patient being decompressed.       
 
         [0142]    The invention further pertains to a method for positioning a patient in a prone position on a patient support structure, which method comprises the following steps:
       providing a disposable patient positioner system according to claim  5 ,   positioning a patient in a supine position on the patient support structure,   attaching the chest body contact sheet of the disposable chest positioner assembly to the chest of the patient by attaching the adhesive zone of the chest body contact sheet to the skin of the patient in the chest area, leaving the abdominal region free, with the inflatable chest cushion of the disposable chest positioner assembly in the deflated state,   attaching the pelvic body contact sheet of the disposable pelvis positioner assembly to the pelvic region of the patient by attaching the adhesive zone of the pelvic body contact sheet to the skin of the patient in the pelvic region, leaving the abdominal region free, with the inflatable pelvis cushion of the disposable pelvis positioner assembly in the deflated state,   transferring the patient from the supine position to a prone position, thereby making the patient come to lie on the patient support structure in a prone position,   with the chest body contact sheet attached to the chest of the patient and the pelvic body contact sheet attached to the pelvic region of the patient and the patient in the prone position, inflating the chest cushion and the pelvis cushion, thereby lifting the patient from the patient support structure by making that the chest cushion and the pelvis cushion together bear the weight of the torso of the patient while the patient is in a prone position with the abdominal region of the patient being decompressed.       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0149]    The invention will be described in more detail below under reference to the drawing, in which in a non-limiting manner exemplary embodiments of the invention will be shown. 
           [0150]    The drawing shows in: 
           [0151]      FIG. 1 : a patient on a patient support structure, in supine position, viewed from above, 
           [0152]      FIG. 2 : a patient on a patient support structure, in supine position, viewed from above, with an embodiment of a chest positioner assembly and an embodiment of a pelvis positioner assembly according to the invention attached to said patient, 
           [0153]      FIG. 3 : a patient in prone position, positioned on a patient support structure by means of an embodiment of a chest positioner assembly and an embodiment of a pelvis positioner assembly according to the invention, 
           [0154]      FIG. 4 : an embodiment of a chest positioner assembly according to the assembly, seen on the rear side, 
           [0155]      FIG. 5 : an embodiment of a chest positioner assembly according to the assembly, seen on the front side, 
           [0156]      FIG. 6 : a second embodiment of a disposable chest positioner assembly according to the invention, seen on the rear side, 
           [0157]      FIG. 7 : a second embodiment of the disposable chest positioner assembly according to the invention, seen on the front side, 
           [0158]      FIG. 8 : an embodiment of a pelvis positioner assembly according to the assembly, seen on the rear side, 
           [0159]      FIG. 9 : an embodiment of a pelvis positioner assembly according to the assembly, seen on the front side, 
           [0160]      FIG. 10 : a second embodiment of a disposable pelvis positioner assembly according to the invention, seen on the rear side, 
           [0161]      FIG. 11 : a second embodiment of the disposable pelvis positioner assembly according to the invention, seen on the front side, 
           [0162]      FIG. 12 : a female patient being positioned by a second embodiment of the patient positioner system according to the invention, 
           [0163]      FIG. 13 : a patient in jackknife position, supported by a patient positioner system according to the invention, 
           [0164]      FIG. 14 : a patient in a position with hyperflexion of the cervical spine, supported by a patient positioner system according to the invention, 
           [0165]      FIG. 15-19 : a further example of an embodiment of a patient positioner system in accordance with the invention, 
           [0166]      FIG. 20 : an examples of a valve assembly that can be used in combination with a chest cushion and/or pelvis cushion in accordance with the invention, or with any other inflatable cushion for patient positioning during diagnosis, treatment or surgery, 
           [0167]      FIG. 21 : a variant of the valve assembly according to  FIG. 20 . 
       
    
    
     DETAILED DESCRIPTION 
       [0168]      FIG. 1  shows a patient  1  on a patient support structure  10 , in supine position, viewed from above. 
         [0169]    In  FIG. 1 , the abdominal region  2  and the inguinal region  3  (left and right parts) of the patient  1  are indicated. Further indicated are the chest region  4  and the pelvic region  5 . 
         [0170]      FIG. 2  shows a patient a on a patient support structure  10 , in supine position, viewed from above. An embodiment of a disposable chest positioner assembly  20  and an embodiment of a disposable pelvis positioner assembly  40  according to the invention are attached to the patient  1 . 
         [0171]    The disposable chest positioner assembly  20  comprises a chest body contact sheet  21  and an inflatable chest cushion  22 . The chest body contact sheet  21  is made of a soft material, for example a material that is used for surgical drapes. 
         [0172]    The chest body contact sheet  21  has a front side and a rear side. On the rear side (not shown in  FIG. 2 ), an upper adhesive zone and a lower adhesive zone are present that allow the disposable chest positioner assembly  20  to be attached to the patient  1 . Attaching the disposable chest positioner assembly  20  to the patient  1  takes place while the patient is in a supine position. 
         [0173]    The inflatable chest cushion  22  is permanently attached to the chest body contact sheet  21 . When medical personnel, e.g. a nurse or a surgeon, attaches the disposable chest positioner assembly  20  to the patient  1 , the inflatable chest cushion  22  is in its deflated state. 
         [0174]    Attaching the chest body contact sheet  21  of the disposable chest positioner assembly  20  to the chest of the patient in this embodiment takes place by attaching the upper adhesive zone of the chest body contact sheet  21  to the skin of a patient  1  in the vicinity of the clavicle of the patient  1  and by attaching the lower adhesive zone of the chest body contact sheet  21  to the skin of a patient  1  in the vicinity of the lower ribs of the patient. 
         [0175]    By doing so, the disposable chest positioner assembly  20  does not extend over the abdominal region  2  of the patient  1 . 
         [0176]    The disposable pelvis positioner assembly  40  comprises a pelvic body contact sheet  41  and an inflatable pelvis cushion  44 . The pelvic body contact sheet  41  is made of a soft material, for example a material that is used for surgical drapes. 
         [0177]    The pelvic body contact sheet  41  has a front side and a rear side. On the rear side (not shown in  FIG. 4 ), adhesive zones are present that allow the disposable pelvis positioner assembly  40  to be attached to the patient  1 . Attaching the disposable pelvis positioner assembly  40  to the patient  1  takes place while the patient is in the supine position. 
         [0178]    The inflatable pelvis cushion  44  is permanently attached to the pelvic body contact sheet  41 . When medical personnel, e.g. a nurse or a surgeon, attaches the disposable pelvis positioner assembly  40  to the patient  1 , the inflatable pelvis cushion  44  is in its deflated state. 
         [0179]    Attaching the pelvic body contact sheet  41  of the disposable pelvis positioner assembly  40  to the pelvic region  5  of the patient takes place by attaching the upper adhesive zone of the pelvic body contact sheet  41  to the skin of a patient just below the abdominal region  2  of the patient and by attaching the lower adhesive zone of the pelvic body contact sheet  21  to the skin of a patient  1  just above the inguinal region  3  of the patient  1 . 
         [0180]    By doing so, the disposable pelvis positioner assembly  40  does not extend over the abdominal region  2  of the patient  1 . 
         [0181]    It is possible that first the chest positioner assembly  20  is attached to the patient  1  and then the pelvis positioner assembly  40  is attached to the patient. Alternatively, it possible that first the pelvis positioner assembly  40  is attached to the patient  1  and then the chest positioner assembly  20 . As a further alternative, t the chest positioner assembly  20  and the pelvis positioner assembly  40  are attached to the patient  1  substantially simultaneously, for example by two different people. 
         [0182]    After the disposable chest positioner assembly  20  and the disposable pelvis positioner assembly  40  have been attached to the patient, the patient  1  is transferred from the supine position to a prone position. As a result, the patient  1  comes to lie on the patient support structure  10  in a prone position. 
         [0183]    With the chest body contact sheet  21  attached to the chest  4  of the patient  1  and the pelvic body contact sheet  41  attached to the pelvic region  5  of the patient  1  and the patient  1  now being in the prone position, a subsequent step is inflating the chest cushion  22  and the pelvis cushion  42 . By doing this, the patient  1  is lifted from the patient support structure  10  and the chest cushion  22  and the pelvis cushion  42  together bear the weight of the torso of the patient  1  while the patient is in a prone position on the patient support structure  10 . The abdominal region  2  of the patient  1  is decompressed, as the chest cushion  22  and the pelvis cushion  42  in their inflated state do not extend over the abdominal region  2  of the patient  1 . 
         [0184]    The chest cushion and the pelvis cushion can be inflated simultaneously or subsequently (one after the other). 
         [0185]      FIG. 3  shows the patient  1  in the prone position, positioned on the patient support structure  10  by means of the chest positioner assembly  20  the pelvis positioner assembly  40  after the chest cushion  22  and the pelvis cushion  42  have been inflated.  FIG. 3  shows that the abdominal region  2  of the patient  1  is decompressed when the patient  1  is positioned in the prone position by the patient positioner system according to the invention. When using the method and system according the invention, the abdomen of the patient can freely bend out towards to patient support  10 . 
         [0186]    The chest cushion  22  and the pelvis cushion  42  together bear the weight of the torso of the patient  1  after they have been inflated. Generally, this is more than 50% of the total body weight. In the embodiment shown in  FIG. 3 , optionally further a head support  12  and a leg support  11  are provided. The optional head support  12  and the optional leg support  11  can be inflatable, but this is not necessary. 
         [0187]    In  FIG. 3 , the thickness of the chest body contact sheet  21  and the pelvic body contact sheet  41  are shown in an exaggerated way. In practice, the chest body contact sheet  21  and the pelvic body contact sheet  41  will be quite thin. 
         [0188]    In the embodiment of  FIG. 2  and  FIG. 3 , as can be seen, the disposable chest positioner assembly  20  and the disposable pelvis positioner assembly  40  do not extend over the supraclavicular region, the lateral cutaneous nerve, the vena saphena magna, the arterie femoralis and the genital region of the patient  1  when they have been applied to the patient  1 . In particular, the chest cushion  22  and the pelvis cushion  42  do not extend over these regions. As a consequence, the supraclavicular region, the lateral cutaneous nerve, the vena saphena magna, the arterie femoralis and the genital region of the patient are decompressed while the patient is in the prone position with the inflated pelvis cushion  42  and the inflated chest cushion  22  bearing the weight of the torso of said patient. 
         [0189]      FIG. 4  and  FIG. 5  show an embodiment of a chest positioner assembly  20  according to the invention.  FIG. 4  shows the chest positioner assembly  20  as seen on the rear side and  FIG. 5  shows the chest positioner assembly  20  as seen on the front side. 
         [0190]    The chest body contact sheet  21  is provided on its rear surface with an upper adhesive zone  23 . In the embodiment shown in  FIG. 4 , the upper adhesive zone  23  has generally the shape of a human clavicle, seen from the ventral side. This is an optional feature, which helps the person who attaches the disposable chest positioner assembly  20  to the patient to attach it at the right position onto the patient  1 . 
         [0191]    The chest body contact sheet  21  is further provided on its rear surface with a lower adhesive zone  24 . In the embodiment shown in  FIG. 4 , the lower adhesive zone  24  has the shape that generally matches the shape of the human lower ribs when seen from the ventral side. As an alternative, the lower adhesive zone could have the shape of a straight line. 
         [0192]    The distance between the upper adhesive zone  23  and the lower adhesive zone  24  is such that it generally matches the size of the human chest, so that the upper adhesive zone  23  can be attached to the skin of a patient in the vicinity of the clavicle and the lower adhesive zone  24  can be attached to the skin of a patient in the vicinity of the lower ribs without folds or creases in the chest body contact sheet  21 . 
         [0193]    The chest body contact sheet  21  is in this embodiment further provided on its rear surface with a central adhesive zone  25 . This central adhesive zone  25  has a shape that generally corresponds to the shape of a human breastbone or a part thereof as seen from the ventral side. The central adhesive zone  25  preferably is attached to the skin of a patient in the vicinity of the breastbone. 
         [0194]    In the embodiment of  FIG. 4 , the chest body contact sheet  21  is optionally further provided on its rear surface with a left adhesive zone  26  and a right adhesive zone  27 . 
         [0195]    In the embodiment of  FIG. 4 , optionally the adhesive zones  23 ,  24 ,  25 ,  26 ,  27  of the chest body contact sheet  21  are connected to each other. Together, they form an adhesive area into which the adhesive zones  23 ,  24 ,  25 ,  26 ,  27  are integrated. 
         [0196]    The central adhesive zone  25  facilitates proper positioning of the disposable chest positioner assembly  20  onto the chest of the patient  1 . In a specific embodiment of the method according to the invention, the central adhesive zoned  25  is attached to the skin of the patient before the upper adhesive zone  23  and the lower adhesive zone  24  of the disposable chest positioner assembly  20  are attached to the patient. The breastbone of the patient provided as clear anatomical landmark that can be used to position the of the disposable chest positioner assembly  20  onto the chest of the patient  1 . 
         [0197]    By first attaching the central adhesive zone  25  onto the chest of the patient, and then folding the chest positioner assembly outwardly to the left and the right, and then attaching the upper adhesive zone  23  and the lower adhesive zone  24  to the patient  1 , e.g. first on the right side and then on the left side or the other way around, an efficient and accurate way of attaching the disposable chest positioner assembly  20  onto the chest of the patient is obtained. 
         [0198]      FIG. 5  shows the chest positioner assembly  20  as seen on the front side.  FIG. 5  shows the inflatable chest cushion  22  which is permanently attached to the front surface of chest body contact sheet  21 . The inflatable chest cushion  22  does not extend over the abdominal region  2  of the patient  1  when the chest positioner assembly  20  is attached to the patient. The inflatable chest cushion  22  is arranged between the upper adhesive zone  23  and the lower adhesive zone  24 . 
         [0199]    In the embodiment of  FIG. 4  and  FIG. 5 , the lower edge of the inflatable chest cushion  22  has a shape that generally matches the shape of the lower ribs of a human as seen from the ventral side. The inflatable chest cushion  22  in its inflated state does not extend over the abdominal region of the patient. 
         [0200]    In the embodiment of  FIG. 4  and  FIG. 5 , the upper edge of the inflatable chest cushion  22  also has a curved shape. This creates space for the head for the situation wherein hyperflexion of the cervical spine is required. 
         [0201]    In the embodiment of  FIG. 4  and  FIG. 5 , the inflatable chest cushion  22  is provided with a flexible air hose  28 . The flexible air hose  28  is connected to the chest cushion  22  at an air supply location  29 . The air supply location is  29  is arranged on the lateral side of the chest cushion  22  in the inflated state, as can be seen in  FIG. 3  as well. The “lateral side” in this embodiment is the peripheral wall of the chest cushion  22 , that extends substantially perpendicular to the chest of the patient when the chest cushion is inflated. 
         [0202]    In the embodiment of  FIG. 4  and  FIG. 5 , the inflatable chest cushion  22  is provided with a check valve  30 , that prevents undesired deflation of the chest cushion  22 . The check valve  30  is also arranged on the lateral side of the chest cushion  22  in the inflated state. 
         [0203]      FIG. 6  and  FIG. 7  show a second embodiment of the disposable chest positioner assembly according to the invention.  FIG. 6  shows the rear side of the chest positioner assembly and  FIG. 7  shows the front side of the chest positioner assembly. 
         [0204]    In this embodiment, the chest positioner assembly is similar to the chest positioner assembly shown in  FIG. 4  and  FIG. 5 . However, the chest cushion  22  has a more or less rectangular shape, while the lower edge and the lower adhesive zone  24  have a shape that generally matches the shape of the lower ribs of a human when seen from the ventral side. Also in this embodiment, the chest cushion in its inflated state does not extend over the abdominal region of the patient. 
         [0205]      FIG. 8  and  FIG. 9  show an embodiment of a pelvis positioner assembly  40  according to the invention.  FIG. 8  shows the pelvis positioner assembly  40  as seen on the rear side and  FIG. 9  shows the pelvis positioner assembly  40  as seen on the front side. 
         [0206]    The pelvis body contact sheet  41  is provided on its rear surface with an upper adhesive zone  43 . In the embodiment shown in  FIG. 8 , the upper adhesive zone  43  has generally the shape of the lower edge of the human abdomen, seen from the ventral side. This is an optional feature, which helps the person who attaches the disposable pelvis positioner assembly  40  to the patient to attach it at the right position onto the patient  1 . 
         [0207]    The pelvis body contact sheet  41  is further provided on its rear surface with a lower adhesive zone  44 . In the embodiment shown in  FIG. 8 , the lower adhesive zone  44  has the shape of a straight line, but as an alternative it could have a shape that generally matches the shape of the human inguinal region when seen from the ventral side. 
         [0208]    The distance between the upper adhesive zone  43  and the lower adhesive zone  44  is such that it generally matches the size of the human pelvis, so that the upper adhesive zone  43  can be attached to the skin of a patient below but adjacent to the lower edge of the abdomen and the lower adhesive zone  44  can be attached to the skin of a patient just above the inguinal region without folds or creases in the pelvis body contact sheet  41 . 
         [0209]    In the embodiment of  FIG. 8 , the pelvis body contact sheet  41  is optionally further provided on its rear surface with a left adhesive zone  46  and a right adhesive zone  47 . 
         [0210]    In the embodiment of  FIG. 8 , optionally the adhesive zones  43 ,  44 ,  46 ,  47  of the pelvis body contact sheet  41  are connected to each other. Together, they form an adhesive area into which the adhesive zones  43 ,  44 ,  46 ,  47  are integrated. 
         [0211]    In the embodiment of  FIG. 8  and  FIG. 9 , the pelvis positioner assembly  40  is provided with a non-inflatable genital region covering flap  51 . The non-inflatable genital region covering flap  51  has a shape that—when the disposable pelvis positioner assembly  40  is attached to a patient—extends over the genital region of the patient  1 . This can also be seen in  FIG. 3 . 
         [0212]    The optional non-inflatable genital region covering flap  51  is provided with attachment members  52  that are adapted to attach the genital region covering flap  51  to the upper legs of the patient  1 . The attachment members can for example be cords or ribbons, optionally provided with Velcro. 
         [0213]      FIG. 9  shows the pelvis positioner assembly  40  as seen on the front side.  FIG. 9  shows the inflatable pelvis cushion  42  which is permanently attached to the front surface of pelvis body contact sheet  41 . The inflatable pelvis cushion  42  does not extend over the abdominal region  2  of the patient  1  when the pelvis positioner assembly  40  is attached to the patient. The inflatable pelvis cushion  42  is arranged between the upper adhesive zone  43  and the lower adhesive zone  44 . 
         [0214]    In the embodiment of  FIG. 8  and  FIG. 9 , the inflatable pelvis cushion  42  is provided with a flexible air hose  48 . The flexible air hose  48  is connected to the pelvis cushion  42  at an air supply location  49 . The air supply location is 49 is arranged on the lateral side of the pelvis cushion  42  in the inflated state, as can be seen in  FIG. 3  as well. The “lateral side” in this embodiment is the peripheral wall of the pelvis cushion  42 , that extends substantially perpendicular to the pelvis of the patient when the pelvis cushion is inflated. 
         [0215]    In the embodiment of  FIG. 8  and  FIG. 9 , the inflatable pelvis cushion  42  is provided with a check valve  50 , that prevents undesired deflation of the pelvis cushion  42 . The check valve  50  is also arranged on the lateral side of the pelvis cushion  42  in the inflated state. 
         [0216]      FIG. 10  and  FIG. 11  show a second embodiment of the disposable pelvis positioner assembly according to the invention.  FIG. 10  shows the rear side of the pelvis positioner assembly and  FIG. 11  shows the front side of the pelvis positioner assembly. 
         [0217]    In this embodiment, the pelvis positioner assembly is similar to the pelvis positioner assembly shown in  FIG. 8  and  FIG. 9 . However, in this embodiment upper edge of the pelvic body contact sheet and the upper edge of the pelvis cushion in this inflated state have a shape the generally matches the lower edge of the abdomen. 
         [0218]      FIG. 12  shows a female patient  1  being positioned by a second embodiment of the patient positioner system according to the invention. 
         [0219]    This second embodiment is generally the same as the embodiment as described above, but now the chest body contact sheet  21  is provided with a pocket  31  for accommodating the breasts of the patient. 
         [0220]    Furthermore, in this second embodiment, the disposable pelvis positioner assembly  40  is not provided with the optional genital region covering flap. 
         [0221]      FIG. 13  shows a patient in jackknife position, supported by a patient positioner system according to the invention. 
         [0222]    In the embodiment of the invention shown in  FIG. 13 , the inflated pelvis cushion positions the hips of the patient above the head and above the legs of the patient. The difference in height between the head and hip of the patient and/or the difference in height between the legs and hip of the patient may in practice be less than what is shown in  FIG. 13 . 
         [0223]      FIG. 14  shows a patient in a position with hyperflexion of the cervical spine, supported by a patient positioner system according to the invention. A head clamp  14  fixes the position of the head of the patient. 
         [0224]    In the embodiment of  FIG. 14 , the shape of the chest positioner assembly, and in particular of the chest cushion, allows the required bending of the neck by leaving room for the head of the patient. 
         [0225]      FIG. 15-19  show a further example of an embodiment of a patient positioner system in accordance with the invention. 
         [0226]      FIG. 15  schematically illustrates the chest cushion  122  of this further embodiment in its inflated state, in perspective.  FIG. 16  shows the chest cushion in accordance with  FIG. 15 , seen from the rear.  FIG. 17  also shows this chest cushion in accordance with  FIG. 15 , but now from the abdominal side, looking towards the neck side. 
         [0227]      FIG. 18  schematically illustrates the pelvis cushion  144  of this further embodiment in its inflated state, in perspective.  FIG. 19  shows this pelvis cushion in accordance with  FIG. 18 , seen from the rear. 
         [0228]    The chest cushion that is shown in fig.,  FIG. 16  and  FIG. 17  belongs to a chest positioner assembly  120 . The chest cushion  122  is disposable, which means that it is intended for single use. 
         [0229]    The chest cushion  122  comprises a rear wall  119 . The rear wall  119  comprises a chest body contact sheet  121 , which forms part of the outer surface of the chest cushion  122  and contacts the skin of the patient during use. 
         [0230]    In this embodiment, the chest cushion has three adhesive strips  123   a ,  123   b ,  123   c  which are present on chest body contact sheet  121  on the rear wall  119  of the chest cushion  122 . These adhesive strips  123   a ,  123   b ,  123   c  allow the chest cushion to be attached to the patient&#39;s chest area. 
         [0231]    Adhesive strip  123   b  is located at the center of the rear wall  119 , and has a shape that generally corresponds to the shape of a human breastbone or a part thereof as seen from the ventral side. The adhesive strip  123   b  is adapted to be attached to the skin of a patient in the vicinity of the breastbone. Therewith, the adhesive strip  123   b  is a central adhesive zone. 
         [0232]    The rear wall  119  of the chest cushion has a neck side end  125  and an abdominal side edge  124 . 
         [0233]    The neck side edge  125  and abdominal side edge  124  both have a concave shape with a radius of curvature. The radius of curvature of the neck side edge  125  of the rear wall  119  is larger than the radius of curvature of the abdominal side edge  124  of the rear wall  119 . 
         [0234]    The distance between the neck side edge  125  and the abdominal side edge  124  of the rear wall  119  at the center of the chest cushion  122 , so generally at the location of the adhesive strip  123   b , is substantially equal to the length of a human breast bone. 
         [0235]    As can be seen in  FIG. 15 ,  FIG. 16  and  FIG. 17 , the rear wall  119  and the front wall  130  of the chest cushion  122  are wider at the neck side end than at the abdominal side end. 
         [0236]    The parts of the adhesive strips  123   a ,  123   b ,  123   c  near the neck side edge  125  of the rear wall  119  together form an upper adhesive zone. The parts of the adhesive strips  123   a ,  123   b ,  123   c  near the abdominal side edge  124  of the rear wall  119  together form a lower adhesive zone. 
         [0237]    In the embodiment shown in  FIG. 15-19 , the chest cushion further comprises a front wall  130 . In use, the front wall  130  engages the patient support, which is e.g. an operation table. 
         [0238]    The front wall  130  of the chest cushion has a neck side end  1135  and an abdominal side edge  134 . 
         [0239]    The neck side edge  135  and abdominal side edge  134  both have a concave shape with a radius of curvature. The radius of curvature of the neck side edge  135  of the front wall  130  is larger than the radius of curvature of the abdominal side edge  134  of the front wall  130 . 
         [0240]    The distance between the neck side edge  135  and the abdominal side edge  134  of the front wall  130  at the center of the chest cushion  122 , is substantially equal to the length of a human breast bone. 
         [0241]    As can be seen in  FIG. 17 , in this particular embodiment, in the inflated state the chest cushion  122  has a larger thickness on the neck side end than at the abdominal side end. 
         [0242]    Also, in this particular embodiment, the rear wall  119  of the chest cushion  122  has a hollow shape, to match the generally convex shape of the human chest. 
         [0243]    In the embodiment of  FIG. 15-19 , the inflatable chest cushion  22  is provided with a flexible air hose  128 . The flexible air hose  128  is connected to the chest cushion  122  at an air supply location  129 . The air supply location  129  is arranged on the lateral side of the chest cushion  122  in the inflated state, as can be seen in  FIG. 15 . The “lateral side” in this embodiment is the peripheral wall  132  of the chest cushion  122 , that extends between the front wall  130  and the rear wall  119 . 
         [0244]    The air hose  128  is connected to a source  131  of pressurized air. 
         [0245]    In the embodiment of  FIG. 15-19 , the inflatable chest cushion  122  is provided with a valve assembly  133  comprises a check valve, a pressure relief valve and a safety relief valve. The check valve, pressure relief valve and safety relief valve are arranged in a common valve housing. Optionally, the pressure relief valve is a manually operable pressure relief valve which requires the use of two hands for actuation. 
         [0246]      FIG. 18  and  FIG. 19  schematically illustrate the pelvis cushion  144  of the disposable pelvis positioner assembly  140  of the embodiment of  FIG. 15-19  in its inflated state. 
         [0247]    The pelvis cushion  144  comprises a rear wall  150 , 
         [0248]    The rear wall of the pelvis cushion comprises a pelvic body contact sheet  151  which is made of a soft material. The pelvic body contact sheet  151  has a rear surface which forms part of the outer surface of the pelvis cushion  144 . 
         [0249]    The pelvic body contact sheet  151  is on the rear surface provided with at least one adhesive zone, here in the form of adhesive strip  153 , which adhesive strip  153  is adapted to be attached to the skin of a patient in the pelvis area. 
         [0250]    The disposable inflatable pelvis cushion  144  has a deflated state and an inflated state. 
         [0251]    The rear wall  150  of the pelvis cushion  144  has an abdominal side edge  155  and a genital side edge  154 . The abdominal side edge  155  and genital side edge  154  have a concave shape having a radius of curvature, wherein the radius of curvature of the abdominal side edge  155  of the rear wall  150  is larger than the radius of curvature of the genital side edge  154  of the rear wall  150 . This can be clearly seen in  FIG. 19 . 
         [0252]    The distance between the abdominal side edge  155  and the genital side edge  154  of the rear wall  150  at the center of the pelvis cushion  144  is substantially equal to the distance between the lower edge of the abdomen and the upper edge of the exterior genitals in a human. 
         [0253]    In the embodiment of  FIG. 15-19 , the pelvis cushion  144  further comprises a front wall  170 , which is located opposite the rear wall  150 . 
         [0254]    In the inflated state, the front wall  170  of the pelvis cushion has an abdominal side edge  175  and a genital side edge  174 . The abdominal side edge  175  and genital side edge  174  have a concave shape having a radius of curvature. The radius of curvature of the abdominal side edge  175  of the front wall  170  is larger than the radius of curvature of the genital side edge  174  of the front wall  170 . 
         [0255]    In this embodiment, the distance between the abdominal side edge  175  and the genital side edge  174  of the front wall  170  at the center of the pelvis cushion  144  is substantially equal to the distance between the lower edge of the abdomen and the upper edge of the exterior genitals in a human. 
         [0256]    In the embodiment of  FIG. 15-19 , the pelvis positioner assembly  140 , is provided with a non-inflatable genital region covering flap  160 . The non-inflatable genital region covering flap  160  has a shape that—when the disposable pelvis positioner assembly  140  is attached to a patient—extends over the genital region of the patient. 
         [0257]    The optional non-inflatable genital region covering flap  160  is in this example provided with adhesive strips  163  for attaching the non-inflatable genital region covering flap  160  to the upper legs of the patient. 
         [0258]    In the embodiment shown, the non-inflatable genital region covering flap  160  is part of the pelvic body contact sheet  151  that extends beyond the rear wall  150  of the pelvis cushion  144 . 
         [0259]    In the embodiment of  FIG. 15-19 , the inflatable pelvis cushion  144  is provided with a flexible air hose  128 . The flexible air hose  128  is connected to the pelvis cushion  144  at an air supply location  129 . The air supply location  129  is arranged on the lateral side of the pelvis cushion  144  in the inflated state, as can be seen in  FIG. 15 . The “lateral side” in this embodiment is the peripheral wall  165  of the pelvis cushion  144 , that extends between the front wall  170  and the rear wall  150 . 
         [0260]    The air hose  128  is connected to a source  131  of pressurized air. 
         [0261]    In the embodiment of  FIG. 15-19 , the inflatable pelvis cushion  144  is provided with a valve assembly  133  comprises a check valve, a pressure relief valve and a safety relief valve. The check valve, pressure relief valve and safety relief valve are arranged in a common valve housing. Optionally, the pressure relief valve is a manually operable pressure relief valve which requires the use of two hands for actuation. 
         [0262]    The inflatable chest cushion  122  and the inflatable pelvis cushion  144  are adapted to in their inflated state together support the torso of the patient on the patient support structure. The shape of the inflatable chest cushion  122  and the inflatable pelvis cushion  144  in their inflated state allows to leave the abdominal region of the patient decompressed. The shape of the inflatable chest cushion  122  and the inflatable pelvis cushion  144  in general prevents incorrect application of these cushions  122 ,  144  to the patient&#39;s body, as the shape of the cushions matches the shape of the patient&#39;s body. Furthermore, anatomical landmarks of the patient&#39;s body (e.g. the breastbone or clavicle) can be used for accurately positioning the cushions  122 ,  144  onto the patient. 
         [0263]      FIG. 20  and  FIG. 21  show examples of a valve assembly  200  that can be used in combination with a chest cushion  22 ,  122  and/or pelvis cushion  44 ,  144  in accordance with the invention, or with any other inflatable cushion for patient positioning during diagnosis, treatment or surgery. 
         [0264]    The valve assembly  200  comprises a housing  210 , a chamber  211  and two connectors  128 * to which a flexible air hose  128  for compressed air or other supply hose for the pressurized medium that is used for inflating the inflatable cushion can be connected. 
         [0265]    Arrow  180  shows the direction of the flow of air or other pressurized medium normally flows when the cushion is being brought into the inflated state. So, arrow  180  shows indicates the air or other pressurized medium flowing away from a source of pressurized fluid (e.g. air) and towards the inflatable cushion. 
         [0266]    The valve assembly  200  comprises a check valve  190 . The check valve  190  blocks a fluid flow coming from the inflatable cushion to the source of pressurized fluid, so in the direction opposite to arrow  180 . A fluid flow coming from the source of pressurized fluid will open the slit  193 , allowing further flow into chamber  211 . A fluid flow coming from the cushion will close the slit  193  and will thus block any flow back into the source of pressurized fluid. This design is known as a duck-bill valve. As an alternative for a duck bill valve, a check valve with a moveable check valve body, e.g. a ball check valve, may be used. 
         [0267]    The valve assembly further comprises a pressure relief valve and a safety relief valve, which are integrated in the example of  FIG. 10 . In this embodiment, the pressure relief valve is adapted to be operated manually. 
         [0268]    A seal body  204  is mounted onto operating rod  201 . The operating rod  201  has a shoulder  205 . A compression spring  202  is provided between the housing  210  and the shoulder  205  of the operating rod  201 . In addition, an actuator element  203 , in the example of  FIG. 20  a rotatable rod, is provided which is connected to the operating rod  201 . As an alternative for the rotatable rod, a rotatable knob may be used. 
         [0269]    In normal operation, the seal body  204  is arranged in a seat  212  in the housing  210 . In this situation, the seal body  204  closes the opening in the seat  212 . 
         [0270]    Pressure can be released form the cushion by making the seal body  204  move away from the seat  212 . This allows the pressurized medium, e.g. pressurized air, to escape from the chamber  211  through the opening in seat  212 . 
         [0271]    The seal body  204  can be moved away from the seat  212  by a user, in particular somebody of the medical team, who turns and/or pulls the actuator element  203  in such a direction that the seal body  204  is moved away from the seat  212 . This will for example be done when the medical team decides that the cushion has been over-inflated, making the cushion too hard for the patient to comfortably lie on. When sufficient pressure has been released, the user releases the actuator element  203  and/or moves it in the opposite direction so that the seal body  204  comes to lie in the seat  212  again, e.g due to the action of the compression spring  202 , and no pressurized medium can escape from the chamber  211  via the seat  212  any more. 
         [0272]    In the case of excessive pressure in the cushion, at an unsafe level, the seal body  204  will press onto the shoulder  205  and away from the seat  212 , in turn compressing the spring  202 . The excessive pressure will then be released through seat  212 . When a safe level of pressure has been attained again, the force of the spring will repress seal body  204  into seat  212 . Herewith, the valve assembly fulfills the function of a safety relief valve. No operation of the actuator element  203  is necessary to release the pressure in this case in order to obtain a safe level of pressure in the cushion again. 
         [0273]    Optionally, in this embodiment, moving the actuator element  203  requires so much force or involves such a complex movement (e.g. a combination of pulling and turning) that a user will need to hold the housing  210  in one hand and operate the actuator element  203  (e.g. by pulling and/or turning) using the other hand. This helps to avoid that pressure is released unintentionally. 
         [0274]    Optionally, the force of the compression spring  202  is selected depending on the size of the cushion, so that for cushions intended for heavy patients, the spring is stronger than for cushions which are intended for lighter patients. 
         [0275]      FIG. 21  shows a variant of the valve assembly  200 . 
         [0276]    During normal operation, the rod  215  is arranged in rod seat  216 . In order to operate the seal body  204  to release some pressure from the cushion, the rod  215  needs to be lifted from its rod seat  216 . For complete deflation of the cushion, the rod  215  can be lifted out of seat  216  and rotated into seat  217  which locks the seal body  204  away from seat  212 . 
         [0277]    One or both of these movements of the rod  215  optionally require the simultaneous use of two hands of the person operating the valve assembly (e.g. one hand holding and moving the rod  215  and one hand holding the valve housing  210 ), and therewith it helps to avoid that pressure is released unintentionally. 
         [0278]    In the embodiment of  FIG. 20  and in the embodiment of  FIG. 21 , optionally the common valve housing has a length (seen in the direction of normal flow of pressure medium, e.g. air, through the valve) of less than 10 centimeter, optionally less than 5 centimeter.