Patent Publication Number: US-11020314-B2

Title: Methods and systems to reduce brain damage

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application No. 62/542,394, filed Aug. 8, 2017, the entire disclosure of which is hereby incorporated by reference for all intents and purposes. 
     This application is also a continuation in part of U.S. application Ser. No. 15/986,466, filed May 22, 2018, which is a continuation in part of U.S. application Ser. No. 15/850,827, filed Dec. 21, 2017, which is a continuation in part of U.S. application Ser. No. 15/601,494, filed May 22, 2017, which is a continuation in part of U.S. application Ser. No. 15/285,063, filed Oct. 4, 2016, which is a continuation in part of U.S. application Ser. No. 15/160,492, filed May 20, 2016, which is a continuation in part of U.S. application Ser. No. 15/133,967, filed Apr. 20, 2016, now U.S. Pat. No. 9,801,782, issued Oct. 31, 2017, which is a continuation in part of U.S. application Ser. No. 14/996,147, filed Jan. 14, 2016, now U.S. Pat. No. 9,750,661, issued Sep. 5, 2017, which is a continuation in part of U.S. application Ser. No. 14/935,262, filed Nov. 6, 2015, now U.S. Pat. No. 9,707,152, issued Jul. 18, 2017, which claims the benefit of U.S. Provisional Application No. 62/242,655, filed Oct. 16, 2015, the complete disclosures of which are hereby incorporated by reference for all intents and purposes. 
     U.S. application Ser. No. 15/986,466, filed May 22, 2018 (referenced above) also claims the benefit of U.S. Provisional Application No. 62/509,469, filed May 22, 2017, the complete disclosure of which is hereby incorporated by reference for all intents and purposes. 
     U.S. application Ser. No. 14/935,262, filed Nov. 6, 2015, now U.S. Pat. No. 9,707,152, issued Jul. 18, 2017 (referenced above) is also a continuation in part of U.S. application Ser. No. 14/677,562, filed Apr. 2, 2015, now U.S. Pat. No. 10,092,481, issued Oct. 9, 2018, which is a continuation of U.S. application Ser. No. 14/626,770, filed Feb. 19, 2015, which claims the benefit of U.S. Provisional Application No. 61/941,670, filed Feb. 19, 2014, U.S. Provisional Application No. 62/000,836, filed May 20, 2014, and U.S. Provisional Application No. 62/087,717, filed Dec. 4, 2014, the complete disclosures of which are hereby incorporated by reference for all intents and purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     Cardiac arrest is a leading cause of death. Despite progress, the vast majority of patients never wake up again after cardiac arrest. While there are many reasons for the currently dismal outcomes, one important reason involves the rapid onset of brain swelling and edema after cardiac arrest and resuscitation techniques. Improvements to reduce brain damage, swelling, and edema after cardiac arrest are needed. 
     BRIEF SUMMARY OF THE INVENTION 
     Embodiments of the invention are directed toward systems, devices, and methods of reducing brain edema and brain swelling. Such techniques reduce the spikes in intracranial pressure (ICP) associated with various resuscitation techniques and result in lower intracranial pressure while increasing cerebral perfusion pressure, cerebral output, and systolic blood pressure (SBP) during CPR and after resuscitation compared with CPR administered to an individual in the flat and supine position. The configuration may also preserve a central blood volume and lower pulmonary vascular resistance and circulate drugs to the brain and heart used during CPR more effectively. This provides a more effective and safe method of performing CPR for extended periods of time. The head and thorax up configuration during CPR and after resuscitation may also preserve the patient in the sniffing position to optimize airway management and reduce complications associated with endotracheal intubation. 
     In one aspect, a method to reduce brain injury and brain swelling is provided. The method may include performing conventional manual CPR and/or performing active compression decompression cardiopulmonary resuscitation on an individual in a supine position with an intrathoracic pressure regulation device. The individual&#39;s head, shoulders, and heart may be elevated relative to the individual&#39;s lower body. The head may be elevated to a height of between about 10 cm and 30 cm above the horizontal plane and the heart may be elevated to a height of between about 1 cm to 10 cm or 2 cm and 10 cm above the horizontal plane. Chest compressions may be performed on the individual and actively decompressing the individual&#39;s chest while the individual&#39;s head, shoulders, and heart are elevated. Intrathoracic pressure of the individual may be regulated, for example, using an impedance threshold device both while the individual is in the supine position and while the individual&#39;s head, shoulders, and heart are elevated relative to the lower body, thereby reducing brain edema during CPR. After a successful resuscitation the head and thorax remain elevated as long as there is adequate blood flow to the brain, which is generally associated with a mean arterial pressure (MAP) of &gt;65 mmHg. 
     In some embodiments a method to reduce brain injury and brain swelling may also include, upon stopping the performance of CPR, maintaining the individual in a head up position with the individual&#39;s head, shoulders, and heart elevated as long as a sufficient mean arterial pressure is maintained to support blood flow to the brain in the head up position. 
     In some embodiments, a method to reduce brain injury and brain swelling may include performing active compression decompression cardiopulmonary resuscitation (ACD-CPR) on an individual while the individual&#39;s heart is at a position of between about 0 cm to 8 cm above horizontal and the individual&#39;s head is at a position of between about 0 and 15 cm above horizontal. The method may also include elevating the individual&#39;s head, shoulders, and heart relative to the individual&#39;s lower body while the individual&#39;s lower body remains generally aligned with the horizontal plane to cause blood to actively drain venous blood from the brain to reduce intracranial pressure. The head may be elevated to a height of between about 10 cm and 30 cm above the horizontal plane and the heart may be elevated to a height of between about 1 cm to 10 cm or 2 cm and 10 cm above the horizontal plane. The method may further include performing chest compressions on the individual and actively decompressing the individual&#39;s chest while the individual&#39;s head, shoulders, and heart are elevated. The method may include regulating an intrathoracic pressure of the individual using a pressure regulation device, such as an impedance threshold device both while the individual is in the supine position and while the individual&#39;s head, shoulders, and heart are elevated relative to the lower body, thereby reducing brain edema during CPR by significantly reducing an amplitude of a venous pressure wave with each chest compression. The method may also include, upon stopping the performance of CPR, maintaining the individual in a head up position with the individual&#39;s head, shoulders, and heart elevated as long as a sufficient mean arterial pressure is maintained to support blood flow to the brain in the head up position. 
     In some embodiments, a method to reduce brain injury and brain swelling includes performing cardiopulmonary resuscitation (CPR) on an individual in cardiac arrest while the individual&#39;s heart is at a position of between about 0 cm to 8 cm above horizontal and the individual&#39;s head is at a position of between about 0 and 15 cm above horizontal. The method may also include elevating the individual&#39;s head, shoulders, and heart relative to the individual&#39;s lower body while the individual&#39;s lower body remains generally aligned with the horizontal plane to cause blood to actively drain venous blood from the brain to reduce intracranial pressure. The head may be elevated to a height of between about 10 cm and 30 cm above the horizontal plane and the heart is elevated to a height of between about 1 cm to 10 cm or 2 cm and 10 cm above the horizontal plane. The method may also include delivering chest compressions to the individual&#39;s chest using a CPR assist device while the individual&#39;s head, shoulders, and heart are elevated and regulating an intrathoracic pressure of the individual using an intrathoracic pressure regulation device both while the individual is in the supine position and while the individual&#39;s head, shoulders, and heart are elevated relative to the lower body, thereby reducing brain edema during CPR by significantly reducing an amplitude of a venous pressure wave with each chest compression. The method may further include, upon stopping the performance of CPR, maintaining the individual in a head up position with the individual&#39;s head, shoulders, and heart elevated as long as a sufficient mean arterial pressure is maintained to support blood flow to the brain in the head up position. 
     In another aspect, a device to reduce brain injury after cardiac arrest and during CPR is provided. The device may include an elevation support having a generally planar surface in general alignment with a horizontal plane. A portion of the generally planar surface may be configured to be bent upward to elevate the head, shoulders, and heart of an individual at an angle of between about 10 and 60 degrees above the horizontal plane. The generally planar surface may include a mounting point that is configured to receive a cardiopulmonary resuscitation (CPR) assist device such that the CPR assist device is positioned in alignment with the heart of the individual. The generally planar surface may also incorporate a CPR assist device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic showing arterial and venous blood flow under normal physiological conditions. 
         FIG. 2  is a schematic showing arterial and venous pressures during conventional closed chest CPR. 
         FIG. 3  is a schematic showing arterial and venous pressures during CPR with the head elevated. 
         FIG. 4A  is a schematic showing a head up configuration according to embodiments. 
         FIG. 4B  is a schematic showing a head up configuration according to embodiments. 
         FIG. 4C  is a schematic showing a head up configuration according to embodiments. 
         FIG. 4D  is a schematic showing a head up configuration according to embodiments. 
         FIG. 5A  is a schematic of a patient receiving CPR in a supine configuration according to embodiments. 
         FIG. 5B  is a schematic of a patient receiving CPR in a head and thorax up configuration according to embodiments. 
         FIG. 6  shows a patient receiving CPR in a head and thorax up configuration according to embodiments. 
         FIG. 7  depicts one embodiment of an elevation device according to embodiments. 
         FIG. 8A  depicts an elevation device in a stowed position according to embodiments. 
         FIG. 8B  depicts the elevation device of  FIG. 8A  in an elevated position according to embodiments. 
         FIG. 9A  depicts an elevation device in a stowed position according to embodiments. 
         FIG. 9B  depicts the elevation device of  FIG. 9A  in an elevated position according to embodiments. 
         FIG. 10A  depicts an elevation device in a stowed position according to embodiments. 
         FIG. 10B  depicts the elevation device of  FIG. 10A  in a partially elevated position according to embodiments. 
         FIG. 10C  depicts the elevation device of  FIG. 10A  in a fully elevated position according to embodiments. 
         FIG. 11A  depicts an elevation device in a lowered position according to embodiments. 
         FIG. 11B  depicts the elevation device of  FIG. 11A  in an elevated position. 
         FIG. 11C  depicts a locking handle of the elevation device of  FIG. 11A . 
         FIG. 11D  depicts the locking handle of the elevation device of  FIG. 11A . 
         FIG. 11E  depict a linear actuator of the elevation device of  FIG. 11A  in an elevated position. 
         FIG. 11F  depict the linear actuator of the elevation device of  FIG. 11A  in a lowered position. 
         FIG. 11G  depicts the elevation device of  FIG. 11A  in a lowered position. 
         FIG. 11H  depicts the elevation device of  FIG. 11A  in an elevated position. 
         FIG. 11I  depicts a latch of the elevation device of  FIG. 11A . 
         FIG. 11J  depicts the latch of the elevation device of  FIG. 11A . 
         FIG. 11K  depicts a release knob of the elevation device of  FIG. 11A . 
         FIG. 11L  depicts a release cable of the elevation device of  FIG. 11A . 
         FIG. 12  is a flowchart of a process for treating brain edema according to embodiments. 
         FIG. 13A  is a schematic showing experimental protocol involving a supine specimen according to embodiments. 
         FIG. 13B  is a schematic showing experimental protocol involving a head up specimen according to embodiments. 
         FIG. 14  is a chart showing cerebral oximetry saturation values during the performance of various types of CPR. 
         FIG. 15  is a chart showing cerebral oximetry saturation values during the performance of various types of CPR. 
         FIG. 16  is a chart showing various pressure values during the performance of head up CPR. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Under normal physiological conditions arterial blood is pumped to the brain and drains through the venous system. This is shown schematically in  FIG. 1  with the red arrow  100  representing arterial blood being pumped to the brain and the blue arrow  102  representing the blood draining through the venous system. During conventional manual closed chest cardiopulmonary resuscitation or standard (S) CPR (performed when the patient is in a generally supine or horizontal position), chest compressions increase arterial and venous pressures simultaneously as depicted in  FIG. 2  with the red arrow  200  representing the arterial pressure and the blue arrow  202  representing the venous pressure. A bidirectional high pressure compression wave is delivered to the brain with every compression. The pressure within the thorax increases with each compression and this rise in pressure is transmitted nearly instantaneously to the brain via the arterial and venous blood vessels and paravertebral venous sinuses, a complex and large network of veins that surround the spinal column from the base of the skull to the sacrum. This is an inherent limitation of S-CPR and can result in a spike in ICP resulting in reduced blood flow to the brain during the compression phase of CPR and a “concussion with every compression”. The ICP can increase to dangerously high levels with each compression during CPR in the horizontal plane. This results in brain damage, brain swelling, and brain injury, especially in the setting of simultaneous lack of oxygen. 
     Brain edema can occur very rapidly, within one hour, in the setting of this trauma. Approximately half of all patients who have cardiac arrest outside the hospital and then undergo CT scan have evidence of moderate to severe brain swelling. These patients rarely wake up. 
     Embodiments of the present invention reduce brain injury after cardiac arrest by reducing the potential for bidirectional high pressure compression waves bombarding the brain with every S-CPR chest compression and the benefits are continued after a successful resuscitation. Embodiments of the invention provide methods and devices to elevate the heart alone or the head and the thorax, to reduce the venous pressure head and thus reduce the potential for bidirectional high pressure compression waves to damage the brain while still providing sufficient arterial blood flow to the brain. The reduction of the venous pressure head is depicted in  FIG. 3  with the arterial blood flow being represented by the red arrow  300  and the reduced venous pressure head being represented by blue arrow  302 . Elevation of the head and heart has recently been shown to reduce ICP as gravity draws venous blood out of the brain almost immediately upon elevation of the head. Thus, the venous pressure wave amplitude is significantly reduced as is the ICP, resulting in a lower potential for brain injury with each chest compression. The lower the concussion potential the lower the chances that brain selling and edema will develop after CPR is discontinued and the patient is resuscitated. 
     To achieve the desired reduction in the venous pressure head, an individual&#39;s entire body could be elevated in a head up tilt position as depicted in  FIG. 4A , elevation of the head alone as depicted in  FIG. 4B , elevation of the upper body to a single angular position by bending the body at the waist as depicted in  FIG. 4C , or elevation of the heart and the head to different angular positions as depicted in  FIG. 4D . For example,  FIG. 4D  shows that the optimal head elevation may include a way to elevate the head and thorax only, with different levels of elevation. While such a change in position may seem obvious, elevation of the head in any of the positions shown in  FIGS. 4A-4D  with simultaneous performance of S-CPR for a prolonged period of time would actually accelerate the odds of death. This is because S-CPR is very inefficient and unable to effectively pump blood uphill to the brain. Blood would flow out of the brain due to gravity and brain perfusion and blood flow would be reduced. 
     In order to pump blood “uphill” to the brain during head up CPR for more than between about 5-10 minutes it is necessary to enhance circulation overall. One approach is to include a mechanism to increase the decompression phase negative intrathoracic pressures during CPR to turn the thorax into a more efficient blood pump. These mechanisms to increase the decompression phase negative intrathoracic pressures during CPR a) enhance blood flow back to the right heart from the non-thoracic structures (e.g. brain, abdomen, extremities), b) lower ICP, and c) enhance forward blood flow to the brain, heart, and other vital organs. One approach is to generate greater decompression phase negative intrathoracic pressure includes use of the family of technologies including the impedance threshold device (ITD), an active compression-decompression CPR device (ACD CPR) device, and other methods to deliver CPR and regulate intrathoracic pressure, including manual and automated CPR devices (LUCAS, AutoPulse, Weil Minicompressor, Michigan thumper, and the like) and intrathoracic pressure regulators. For example, CPR with at least the head and heart elevated may be performed using any one of a variety of manual or automated conventional CPR devices (e.g. active compression-decompression CPR, load-distributing band, or the like) alone or in combination with any one of a variety of systems for regulating intrathoracic pressure, such as a threshold valve that interfaces with a patient&#39;s airway (e.g., an ITD), the combination of an ITD and a Positive End Expiratory Pressure valve, or other means to regulate intrathoracic pressure to generate a sub-atmospheric pressure during the decompression phase of CPR. When CPR is performed with the head and heart elevated, gravity drains venous blood from the brain to the heart, resulting in refilling of the heart after each compression and a substantial decrease in ICP, thereby reducing resistance to forward brain flow. This maneuver also reduces the likelihood of simultaneous high-pressure waveform simultaneously compressing the brain during the compression phase. While this may represent a potential significant advance, tilting the entire body upward has the potential to reduce coronary and cerebral perfusion during a prolonged resuscitation effort since over time gravity will cause the redistribution of blood to the abdomen and lower extremities. 
     Some of the head up devices (HUD) described herein mechanically elevate the thorax and the head, maintain the head and thorax in the correct position for CPR when head up and supine using an expandable and retractable thoracic back plate and a neck support, and allow a thoracic plate to angulate during head elevation so the piston of a CPR assist device always compresses the sternum in the same place and a desired angle (such as, for example, a right angle) is maintained between the piston and the sternum during each chest compression. Embodiments were developed to provide each of these functions simultaneously, thereby enabling maintenance of the compression point at the anatomically correct place when the patient is flat (supine) or their head and chest are elevated. 
     In some embodiments, it may be advantageous to carefully control the speed at which a patient is elevated and/or lowered before, during, and/or after CPR. For example, it is advantageous to elevate the head slowly when first starting CPR since the blood flow “uphill” may barely be adequate to provide sufficient blood flow to the head and brain. In other words, it takes time to pump blood uphill with the types of chest compression techniques described herein, so it is advantageous to elevate the patient&#39;s upper body slowly to make this uphill pumping easier. In contrast, blood drains rapidly from the head when the patient has no blood pressure and the head and upper body are elevated. As a result, there may be a need to lower the head fairly rapidly to prevent blood loss in the brain if CPR is stopped while the head is elevated but the patient is still in cardiac arrest. Typically, this means that the patient&#39;s head and upper body may be elevated at a different rate than it is lowered. For example, the patient&#39;s head may be elevated over a period of between about 2 and 60 seconds, and typically between about 5 and 20 seconds. The patient&#39;s head may be lowered between about 1 and 10 seconds, and typically between about 1-5 seconds. 
     The elevation devices described herein may include and/or be used in conjunction with one or more physiological sensors to determine rates and timing of elevation and lowering. For example, if the end tidal CO 2  (ETCO 2 ) is being measured as a non-invasive indicator of circulation, the head and thorax could be elevated towards the desired target height but that process could be slowed or stopped once the ETCO 2  levels off or starts to decrease, indicating that further elevation would potentially reduce overall circulation within the patient. In another example, the patient on the elevation device may be monitored using an electrocardiogram (ECG) or a means to non-invasively assess ICP or cerebral perfusion or cerebral perfusion pressure, either directly or indirectly. The ECG may detect a regular heart rhythm even if the individual has no palpable pulse. Based on this detection of the regular heart rhythm, it may be determined to stop the performance of chest compressions and to promptly lower the head, heart, and shoulders to the horizontal plane. This ensures that when CPR is stopped and it is observed that there is a regular heart rhythm but there is an absence of a palpable pulse (a condition termed pulseless electrical activity), the head, heart, and shoulders are rapidly lowered so that excessive blood does not drain from the brain while attempting to lower the patient. In other words, although the patient may have a stable or regular heart rhythm so that CPR could potentially be stopped, the patient&#39;s heart may not be strong enough to keep pumping blood “uphill” and so the patient is quickly lowered so that the blood in the brain does not immediately drain. It will be appreciated that other sensors [e.g. blood pressure, end tidal CO 2 , cerebral oximetry and flow and pressure, cerebral or thoracic or carotid artery impedance, etc.] may be used in conjunction with the elevation device to determine: when to start and/or stop CPR, when to elevate and/or lower a patient&#39;s upper body, a degree of elevation of the patient&#39;s upper body, a rate of elevation or lowering of the patient&#39;s upper body, and/or other parameters of CPR and/or ITPR. 
     In some embodiments, the elevation and/or de-elevation declination speeds of an elevation device may be regulated by a controller. For example, the controller may adjust an actuation speed of a motor or other elevation mechanism to raise or lower an upper support surface of the elevation device within the necessary time frame. In some embodiments, a hydraulic lift mechanism may be used to elevate the upper support surface. In such embodiments, the hydraulic lift mechanism may be gradually pressurized to elevate the upper support surface. To quickly lower the upper support surface, a pressure valve may be opened allowing the pressure within the hydraulic lift mechanism to quickly drop, allowing the upper support to be lowered to a generally supine position very rapidly. Other lock and release handle mechanical devices could also be used to slowly elevate and rapidly lower the head and upper thorax as medically needed. 
     In one embodiment, an elevation device may include an elevation support having a generally planar surface in general alignment with a horizontal plane. The generally planar surface may be positioned under an individual to support the individual in a supine position. A portion of the generally planar surface may be configured to be bent upward to elevate the head, shoulders, and/or heart of an individual at an angle of between about 10 and 60 degrees above the horizontal plane. In some embodiments, the generally planar surface may be configured to bend upward at a position in line with the individual&#39;s waist to elevate the entire upper body. In other embodiments, the generally planar surface may be configured to bend at a higher position to elevate just the head, shoulders, and/or heart of the individual. In some embodiments, the generally planar surface is configured to bend at multiple locations to allow the heart and head to be elevated at different angles. As just one example, the fulcrum of the bend may be at the waist and/or mid-back level. In some embodiments, the generally planar surface includes a mounting point that is configured to receive a CPR assist device, such as a manual and/or automatic chest compression and/or decompression device, such that the CPR assist device is positioned in alignment with the heart of the individual. In some embodiments, the CPR assist device may be permanently attached and/or assembled with the elevation device such that the elevation device and the CPR assist device are a single unit. The elevation device may further include and/or be used in conjunction with an ITD and/or other mechanism for intrathoracic pressure regulation. 
     Turning now to  FIG. 5A , a demonstration of the standard supine (SUP) CPR technique is shown. Here, a patient  500  is positioned horizontally on a flat or substantially flat surface  502  while CPR is performed. CPR may be performed by hand and/or with the use of an automated CPR device and/or ACD+CPR device  504 . In contrast, a head and thorax up (HUP) CPR technique is shown in  FIG. 5B . Here, the patient  500  has his head and thorax elevated above the rest of his body, notably the lower body. The elevation may be provided by one or more wedges or angled surfaces  506  placed under the patient&#39;s head and/or thorax, which support the upper body of the patient  500  in a position where both the head and thorax are elevated, with the head being elevated above the thorax. HUP CPR may be performed with ACD alone, with the ITD alone, with the ITD in combination with conventional standard CPR alone, and/or with ACD+ITD together. Such methods regulate and better control intrathoracic pressure, causing a greater negative intrathoracic pressure during CPR when compared with conventional manual CPR. In some embodiments, HUP CPR may also be performed in conjunction with extracorporeal membrane oxygenation (ECMO). 
       FIG. 6  depicts a patient  600  having the head  602  and thorax  604  elevated above the lower body  606  using elevation device  618 . This may be done, for example, by using one or more supports of elevation device  618  to position the patient  600  appropriately. Here thoracic support  608  is positioned under the thorax  604  to elevate the thorax  604  to a desired height B, which is typically between about 6 cm and 8 cm. Upper support  610  is positioned under the head  602  such that the head  602  is elevated to a desired height A, typically between about 10 cm and 30 cm. Thus, the patient  600  has its head  602  at a higher height A than thorax at height B, and both are elevated relative to the flat or supine lower body at height C. Typically, the height of thoracic support  608  may be achieved by the thoracic support  608  being at an angle of between about 0° and 15° from a substantially horizontal plane with which the patient&#39;s lower body  606  is aligned. Upper support  610  is often at an angle between about 15° and 45° above the substantially horizontal plane. In some embodiments, one or both of the upper support  610  and thoracic support  608  is adjustable such that an angle and/or height may be altered to match a type a CPR, ITP regulation, and/or body size of the individual. As shown here, thoracic plate or support  608  is fixed at an angle, such as between 0° and 15° from a substantially horizontal plane. The upper support  610  may adjust by pivoting about an axis  614 . This pivoting may involve a manual adjustment in which a user pulls up or pushes down on the upper support  610  to set a desired position. In other embodiments, the pivoting may be driven by a motor or other drive mechanism. For example, a hydraulic lift coupled with an extendable arm may be used. In other embodiments, a screw or worm gear may be utilized in conjunction with an extendable arm or other linkage. Any adjustment or pivot mechanism may be coupled between a base of the support structure and the upper support  610 . In some embodiments, a neck support may be positioned on the upper support to help maintain the patient in a proper position. 
     As one example, the lower body  606  may define a substantially horizontal plane. A first angled plane may be defined by a line formed from the patient&#39;s chest  604  (heart and lungs) to his shoulder blades. A second angled plane may be defined by a line from the shoulder blades to the head  602 . The first plane may be angled about between 5° and 15° above the substantially horizontal plane and the second plane may be at an angle of between about 15° and 45° above the substantially horizontal plane. In some embodiments, the first angled plane may be elevated such that the heart is at a height of about 4-8 cm above the horizontal plane and the head is at a height of about 10-30 cm above the horizontal plane. 
     The type of CPR being performed on the elevated patient may vary. Examples of CPR techniques that may be used include manual chest compression, chest compressions using an assist device such as chest compression device  612 , either automated or manually, ACD CPR, a load-distributing band, standard CPR, stutter CPR, and the like. Such processes and techniques are described in U.S. Pat. Pub. No. 2011/0201979 and U.S. Pat. Nos. 5,454,779 and 5,645,522, all incorporated herein by reference. Further, various sensors may be used in combination with one or more controllers to sense physiological parameters as well as the manner in which CPR is being performed. The controller may be used to vary the manner of CPR performance, adjust the angle of inclination, the speed of head and thorax rise and descent, provide feedback to the rescuer, and the like. Further, a compression device could be simultaneously applied to the lower extremities or abdomen to squeeze venous blood back into the upper body, thereby augmenting blood flow back to the heart. Further, a compression-decompression band could be applied to the abdomen that compresses the abdomen only when the head and thorax are elevated either continuously or in a pulsatile manner, in synchrony or asynchronously to the compression and decompression of the chest. Further, a rigid or semi-rigid cushion could be simultaneously inserted under the thorax at the level of the heart to elevate the heart and provide greater back support during each compression. 
     Additionally, a number of other procedures may be performed while CPR is being performed on the patient in the torso-elevated state. One such procedure is to periodically prevent or impede the flow in respiratory gases into the lungs. This may be done by using a threshold valve, sometimes also referred to as an impedance threshold device (ITD) that is configured to open once a certain negative intrathoracic pressure is reached. The invention may utilize any of the threshold valves or procedures using such valves that are described in U.S. Pat. Nos. 5,551,420; 5,692,498; 5,730,122; 6,029,667; 6,062,219; 6,810,257; 6,234,916; 6,224,562; 6,526,973; 6,604,523; 6,986,349; and 7,204,251, the complete disclosures of which are herein incorporated by reference. 
     Another such procedure is to manipulate the intrathoracic pressure in other ways, such as by using a ventilator or other device to actively withdraw gases from the lungs. Such techniques as well as equipment and devices for regulating respirator gases are described in U.S. Pat. Pub. No. 2010/0031961, incorporated herein by reference. Such techniques as well as equipment and devices are also described in U.S. patent application Ser. Nos. 11/034,996 and 10/796,875, and also U.S. Pat. Nos. 5,730,122; 6,029,667; 7,082,945; 7,410,649; 7,195,012; and 7,195,013, the complete disclosures of which are herein incorporated by reference. 
     In some embodiments, the angle and/or height of the head and/or heart may be dependent on a type of CPR performed and/or a type of intrathoracic pressure regulation performed. For example, when CPR is performed with a device or device combination capable of providing more circulation during CPR, the head may be elevated higher, for example 10-30 cm above the horizontal plane (10-45 degrees) such as with ACD+ITD CPR. When CPR is performed with less efficient means, such as manual conventional standard CPR, then the head may be elevated less, for example 10-20 cm or 10 to 20 degrees. 
     A variety of equipment or devices may be coupled to or associated with the structure used to elevate the head and torso to facilitate the performance of CPR and/or intrathoracic pressure regulation. For example, a coupling mechanism, connector, or the like may be used to removably couple a CPR assist device to the structure. This could be as simple as a snap fit connector to enable a CPR assist device to be positioned over the patient&#39;s chest. Examples of CPR assist devices that could be used with the elevation device (either in the current state or a modified state) include the Lucas device, sold by Physio-Control, Inc. and described in U.S. Pat. No. 7,569,021, the entire contents of which is hereby incorporated by reference, the Defibtech Lifeline ARM—Hands-Free CPR Device, sold by Defibtech, the Thumper mechanical CPR device, sold by Michigan Instruments, automated CPR devices by Zoll, such as the AutoPulse, as also described in U.S. Pat. No. 7,056,296, the entire contents of which is hereby incorporated by reference, the Weil Mini Chest Compressor Device, such as described in U.S. Pat. No. 7,060,041 (Weil Institute), and the like. Additional devices that could be coupled to the structure include an external defibrillator/pacing system and physiological sensors to assess the patient&#39;s physiological status. The structure thereby serves as a means to elevate the head and thorax, provide CPR, and as a workstation for other tools and equipment to facilitate the resuscitation effort. 
     In some embodiments, an elevation device, such as those described in U.S. application Ser. No. 15/850,827 and U.S. application Ser. No. 15/601,494, the entire contents of which are hereby incorporated by reference, may be programmed to perform sequential elevation HUP CPR and/or used in the treatment of other low blood flow conditions as described herein. For example, an elevation device may include a base and an upper support coupled with the base. The upper support may be configured to elevate an individual&#39;s heart, shoulders, and head relative to horizontal. In some embodiments, the upper support may include a single support surface that is configured to elevate the heart and head at a single angle, such as by bending the patient at or near the waist. In other embodiments, the upper support may include multiple support surfaces that may elevate the heart and head at different angles. The upper support may include an adjustment mechanism that is configured to adjust a degree of elevation of the upper support. For example, a motor or other actuator may be used to drive the angular and/or height adjustment of the upper support relative to the base. In some embodiments, a controller may be coupled with the adjustment mechanism and may be used to control the elevation of the upper support. For example, the controller may execute instructions that determine when and to what degree the adjustment mechanism adjusts the elevation position of the upper support. This may be based off of timing instructions that are derived from empirical studies and/or the elevation may be controlled based on one or more physiological parameters measured by one or more sensors that are in communication with the controller. For example, blood flow sensors, blood pressure sensors, end tidal CO 2  sensors, cerebral oximetry sensors, and/or sensors that monitor other physiological parameters that correlate directly or indirectly with cardio-pulmonary circulation and perfusion may be connected to the controller such that the controller may make adjustments in elevation degree and/or timing based on the sensed parameters. 
     The elevation device may also include a chest compression device, such as an automated chest compression device. In some embodiments, the chest compression device may be a load distributing band, a piston-based chest compression device, a combination of a load distributing band and an active decompression device, and/or other automated and/or manually actuated chest compression device. In some embodiments, the chest compression device may be configured to actively decompress the individual&#39;s chest between each compression such that the chest compression device may be used in the performance of ACD-CPR. In some embodiments, the controller may be coupled with the chest compression device such that the controller may control a rate and/or timing of the chest compressions being delivered to an individual according to the sequential elevation procedures described herein. The compression depth, decompression depth, rate of compression and decompression, and/or duty cycle may be varied based on a particular individual and/or based on measurements from the physiological sensors. In some embodiments, the CPR may be delivered continuously or with pauses for a positive pressure breath and/or with 3-5 short and intentional pauses at the start of CPR to allow for reperfusion injury protection. In each of these examples, the head and thorax can also be lowered if clinically required, in some cases rapidly in less than 6 seconds. 
     As an individual&#39;s head is elevated using an elevation device, such as elevation device  618 , the individual&#39;s thorax is forced to constrict and compress, which causes a more magnified thorax migration during the elevation process. This thorax migration may cause the misalignment of a chest compression device, which leads to ineffective, and in some cases, harmful, chest compressions. It can also cause the head to bend forward thereby potentially restricting the airway. Thus, maintaining the individual in a proper position throughout elevation, without the compression and contraction of the thorax, is vital to ensure that safe and effective CPR can be performed. Embodiments of the elevation devices described herein provide upper supports that may expand and contract, such as by sliding along a support frame to permit the thorax to move freely upward and remain elongate, rather than contract, during the elevation process. For example, the upper support may be supported on rollers with minimal friction. As the head, neck, and/or shoulders are lifted, the upper support may slide away from the thoracic compression, which relieves a buildup of pressure on the thorax and minimizes thoracic compression and migration. Additionally, such elevation devices are designed to maintain optimal airway management of the individual, such as by supporting the individual in the sniffing position throughout elevation. In some embodiments, the upper supports may be spring biased in a contraction direction such that the only shifting or expansion of the upper support is due to forces from the individual as the individual is subject to thoracic shift. Other mechanisms may be incorporated to combat the effects of thoracic shift. For example, adjustable thoracic plates may be used that adjust angularly relative to the base to ensure that the chest compression device remains properly aligned with the individual&#39;s sternum. Typically, the thoracic plate may be adjusted between an angle of between about 0° and 8° from a substantially horizontal plane. In some embodiments, as described in greater detail below, the adjustment of the thoracic plate may be driven by the movement of the upper support. In such embodiments, a proper amount of thoracic plate adjustment can be applied based on the amount of elevation of the upper support. 
     In traditional CPR the patient is supine on an underlying flat surface while manual or automated CPR is implemented. During automated CPR, the chest compression device may migrate due to limited stabilization to the underlying flat surface, and may often require adjustment due to the migration of the device and/or body migration. This may be further exaggerated when the head and shoulders are raised. The elevation devices described herein offer a more substantial platform to support and cradle the chest compression device, such as, for example, a LUCAS device, providing stabilization assistance and preventing unwanted migratory motion, even when the upper torso is elevated. The elevation devices described herein provide the ability to immediately commence CPR in the lowered/supine position, continuing CPR during the gradual, controlled rise to the “Head-Up/Elevated” position. Such elevation devices provide ease of patient positioning and alignment for automated CPR devices. Correct positioning of the patient is important and readily accomplished with guides and alignment features, such as a shaped shoulder profile, a neck/shoulder support, a contoured thoracic plate, as well as other guidelines and graphics. The elevation devices may incorporate features that enable micro adjustments to the position of an automated CPR device position, providing control and enabling accurate placement of the automated CPR device during the lift process. In some embodiments, the elevation devices may establish the sniffing position for intubation when required, in both the supine position and during the lifting process. Features such as stationary pads and adjustable cradles may allow the reduction of neck extension as required while allowing ready access to the head for manipulation during intubation. 
     In some embodiments, the chest compression device  612  and the elevation device  618  may share a common power source. For example, the chest compression device  612  or the elevation device  618  may include a power source, such as a power cord and/or battery. The non-powered device may then plug into the other device to share the power source. In other embodiments, the chest compression device  612  and the elevation device  618  may be formed as a single device, with the elevation mechanism of the elevation device  618  and the chest compression device  612  both being wired to a single power source. 
     Additionally, the chest compression device  612  and/or elevation device  618  may be configured to communicate with other devices, such as computers, mobile devices like mobile phones and tablet computers, e-readers, other medical equipment, such as electrocardiographs and defibrillators, and the like. To enable such communication, one or more wired and/or wireless communication networks may be established. For example, various data cables may be used to communicatively couple the chest compression device  612  and/or elevation device  618  to one or more remote devices. In some embodiments, the chest compression device  612  and/or elevation device  618  may include a wireless communications interface that is configured to communicate with one or more remote devices using WiFi, Bluetooth, 3G, 4G, LTE, and/or other wireless communications protocols. 
     In some embodiments, the elevation device  618  may be coupled with a stretcher-like device for transport that has features that allow the heart and head to be elevated above the plane of the abdomen and lower extremities. For example, the stretcher or stretcher-like device may include rails or other rigid or semi-rigid support members that may be used to secure the elevation device  618  and/or the chest compression device  612  to the stretcher. The elevation device  618  and/or the chest compression device  612  may be coupled to the support members using clamps cables, and/or other securement mechanisms that may ensure the elevation device  618  and/or the chest compression device  612  do not shift relative to the stretcher. In some embodiments, the elevation device serve as a stretcher as well. 
     In the embodiment shown in  FIG. 7 , an elevation device may take the form of a wedge  700  or other pre-formed device. The wedge  700  may be configured to be placed on a support surface, such as a floor, stretcher, bed, ground, etc., and under an individual to raise the individual&#39;s head, shoulders, and heart. In some embodiments, the wedge  700  may be designed such that a portion of the wedge  700  that is designed to support the area of the chest around the patient&#39;s heart is at a different, oftentimes lower, angle than a portion of the wedge  700  that supports the shoulders and head. For example, the portion of the wedge  700  that supports the heart may be at an angle of between about 0° and 15° relative to horizontal such that the heart is elevated between about 1 cm to 10 cm or 2 cm and 10 cm (typically about 10 cm) above the support surface. The portion of the wedge  700  that supports the shoulders and head may be at an angle of between about 15° and 45° relative to horizontal such that the shoulders and/or head are elevated between about 10 cm and 30 cm (typically about 20 cm) above the support surface. Further, the portion of the pre-formed device under the chest may be rigid so that chest compressions are more effective as the chest is compressed rather than the structure under the chest (e.g. a mattress). 
     In some embodiments, the wedge  700  may include a depression  702  that is configured to receive the patient&#39;s head. The depression  702  allows the occiput portion of the head to be positioned downward, opening the patient&#39;s airways. In some embodiments, some or all of the wedge  700  may be formed with a curved profile such that a body of the wedge curves downward from its edges along a length of the wedge  700 . This shape helps the wedge  700  more closely conform to a shape of the patient&#39;s back. In some embodiments, the wedge  700  may include a mounting support  704  on each side of the wedge  700  that allows a chest compression device (not shown) to be coupled with the wedge  700  at a position that is generally aligned with the patient&#39;s heart. 
     The wedge  700  may be formed of a semi rigid material, such as a foam or other synthetic material. The wedge  700  may be a semi-rigid material that allows for some flexing. This flexing may be particularly helpful when the wedge  700  is used in conjunction with a chest compression device, as the flexibility ensures that the right amount force applied to the patient&#39;s chest. For example, a central portion of the wedge  700  may flex in the presence of excessive force, thereby acting as a flexible back plate to absorb some of the force. For example, as a plunger of a chest compression device is pressed into the patient&#39;s chest, some force is transmitted through the patient to the wedge  700 . The wedge  700  may be configured to bend away from the patient if this transferred force exceeds a threshold. This allows for the delivery of compression at the appropriate depth for patients with differing chest wall sizes and the stiffness of their skeletal structure and/or their musculature. This helps prevent broken ribs and/or other injuries to the patient caused by too much force being applied to the patient&#39;s chest, as the flexing back plate, rather than the ribs or other body structures, absorbs a significant portion of the excess force. It should be appreciated that the portion of the wedge  700  under the heart and thorax could also contain force, pressure, impedance, and/or position sensors to provide feedback to the chest compression device, assuring the proper compression depth and force are delivered, even though the amounts needed to provide the proper CPR may differ from patient to patient and may change over time. 
     In some embodiments, a contact surface of the wedge  700  may be textured and/or coated with and/or formed from a non-slip material to help prevent the patient from sliding downward, thereby maintaining the patient in a desired treatment position. In some embodiments, the wedge  700  may include a neck pad, armpit flaps, and/or other positioning aids to both help properly positioning a patient on the wedge and to ensure that the patient remains in the correct treatment position. For example, a neck pad may be provided that supports the individual&#39;s neck. The neck pad may be configured to support the individual&#39;s spine in a region of the individual&#39;s C7 and C8 vertebrae. Such positioning may help maintain the patient in the sniffing position to maintain the patient&#39;s airway in a proper position for endotracheal intubation. In such a position, the neck is flexed and the head extended, allowing for patient intubation, if necessary, and airway management. 
     In some embodiments, the chest compression device and wedge  700  may be configured to communicate with each other and/or with remote devices. For example, one or more network or other data cables and/or wireless interfaces may couple processors and/or sensors of each device to one another and/or with remote devices such as computers, mobile devices like mobile phones and tablet computers, e-readers, other medical equipment, such as electrocardiographs and defibrillators, and the like. Data regarding the CPR rate, force applied to the patient, and/or other data may be measured and shared between the devices. Additionally, data from physiological sensors may be shared with the chest compression device. This physiological data, such as ICP, blood flow data, blood pressure, intrathoracic pressure measurements, and the like may be used to control the various parameters such as chest compression depth and/or force and the like. 
     In some embodiments, the wedge  700  may be coupled with a stretcher-like device for transport that has features that allow the heart and head to be elevated above the plane of the abdomen and lower extremities. For example, the stretcher or stretcher-like device may include rails or other rigid or semi-rigid support members that may be used to secure the wedge  700  and/or a chest compression device to the stretcher. The wedge  700  and/or the chest compression device  32  may be coupled to the support members using clamps, cables, and/or other securement mechanisms that may ensure the wedge  700  and/or the chest compression device do not shift relative to the stretcher. 
     In some embodiments, the wedge  700  may include a stowable shelf (not shown). The stowable shelf may be configured to be maintained in a stowed position in which most or all of the shelf is disposed within an interior of the wedge  700 , with only a handle and/or outer surface of the stowable shelf remaining exposed exteriorly of the elevation device. The stowable shelf may be extended outward into an extended position in which all or a large portion of the stowable shelf protrudes from a side of the wedge  700 . This protruding portion may be used by medical personnel as a support for their knees so that the rescuer may be elevated relative to the ground and positioned properly for administering CPR. For example, the stowable shelf may be configured to elevate the rescuer to a height of between about 2 and 4 inches relative to the ground. Oftentimes, the stowable shelf may be positioned on a roller track or other sliding mechanism that enables the stowable shelf to be manipulated between the stowed position and the extended position. 
       FIGS. 8A-10C  illustrate embodiments of simplified elevation devices according to the invention. Turning first to  FIG. 8A , an elevation device  800  is shown in a stowed position. Elevation device  800  may be configured to be supported by a generally flat surface, such as a floor, the ground, a stretcher, a table, a bed, and/or other generally flat, supportive surface. The elevation device  800  may be configured to elevate the entire upper body of an individual, bending the individual at the waist. Elevation device  800  includes two support surfaces that are moveable relative to one another. A first support surface  802  may be generally aligned with a first plane and may be configured to support the individual&#39;s lower body at a position below the individual&#39;s waist. In some embodiments, the first support surface  802  may be entirely flat, and thus completely aligned with a first plane, while in other embodiments, the first support surface  802  may have a contoured profile that is largely, but not entirely, aligned with a single plane. The first plane may be aligned with a horizontal plane or at a slight angle (between about 0 and 5 degrees) above the horizontal plane. The first support surface  802  may be pivotally coupled with a second support surface  804  that is generally aligned with a second plane. The second support surface  804  may be similar to the upper supports described elsewhere herein. A pivot point  814  may couple the two support surfaces together at a position proximate an individual&#39;s waist. The second support surface  804  may be configured to be positioned under and to support the entirety of the individual&#39;s upper body, including the heart, shoulders, and head. The second support surface  804  is angularly positionable relative to the first support surface  802  such that an angle of the second plane may be adjusted. When pivoted, the second support surface  804  may be raised to elevated the individual&#39;s upper body as shown in  FIG. 8B . For example, the second support surface  804  may be pivoted between about 5 and 45 degrees above the first support surface  802  and/or the horizontal plane to sufficiently elevate the individual&#39;s head, shoulders, and heart relative to the rest of the patient&#39;s body. 
     In some embodiments, the first support surface  802  and/or the second support surface  806  may have a curved profile such that a medial section of the portion of the support surface is lower relative to end sections of the portion of the support surface. Such a profile may allow the support surface to more closely match the contour of an individual&#39;s back. Additionally, the curved profile may make the support surface flexible. This flexibility helps when the elevation device  800  is used in conjunction with a chest compression device, as the flexibility ensures that the right amount force applied to the patient&#39;s chest. For example, a central portion of the support surface may flex in the presence of excessive force, thereby acting as a flexible backplate to absorb some of the force. For example, as a plunger of a chest compression device is pressed into the patient&#39;s chest, some force is transmitted through the patient to the support surface. The support surface may be configured to bend away from the patient if this transferred force exceeds a threshold. This allows for the delivery of compression at the appropriate depth for patients with differing chest wall sizes and stiffness&#39;s. This helps prevent broken ribs and/or other injuries to the patient caused by too much force being applied to the patient&#39;s chest, as the flexing backplate, rather than the ribs or other body structures, absorbs a significant portion of the excess force. In another example the compression device also actively decompresses the chest back to or above the resting chest position. Such a head up CPR device design is particularly useful when the elevation device  800  is used in conjunction with a chest compression device  812  such as the Lucas device, sold by Physio-Control, Inc. and/or the Zoll AutoPulse. However, it will be appreciated that the flexible support surface may be used in conjunction with any of the embodiments of elevation devices described herein. It should be appreciated that the portion of the elevation device  800  under the heart and thorax could also contain force, pressure, impedance, and/or position sensors to provide feedback to the chest compression device  812 , assuring the proper compression depth and force are delivered, even though the amounts needed to provide the proper CPR may differ from patient to patient and may change over time. 
     In some embodiments, a contact surface of the first support surface  802  and/or the second support surface  804  may be textured and/or coated with and/or formed from a non-slip material to help prevent the patient from sliding downward during elevation of the second support surface  804 , thereby maintaining the patient in a desired treatment position. In some embodiments, a neck pad, head cradle, arm pit flaps, and/or other positioning aids may be included on the first support surface  802  and/or the second support surface  804  to both aid in properly positioning a patient on the elevation device  800  and to ensure that the patient remains in the correct treatment position throughout the elevation and lowering of the patient&#39;s upper body. For example, a neck pad may be provided that supports the individual&#39;s neck. The neck pad may be configured to support the individual&#39;s spine in a region of the individual&#39;s C7 and C8 vertebrae. Such positioning may help maintain the patient in the sniffing position to maintain the patient&#39;s airway in a proper position for endotracheal intubation. In such a position, the neck is flexed and the head extended, allowing for patient intubation, if necessary, and airway management. In some embodiments, a position and/or angle of the neck pad and/or a different head support, such as a head cradle or head support pad, may be adjustable. This allows for better airway management as well as better support of the patient&#39;s head, and allows the elevation device  800  to be usable with patients of various sizes and flexibility levels. For example, a patient with a particularly stiff neck may need to be positioned and/or supported differently than a patient having a neck with normal levels of flexibility. The neck pad and/or head support may be configured to raise and/or lower relative to the second support surface  804  to adjust the height of the patient&#39;s head and/or neck. For example, second support surface  804  may have an opening that is configured to receive the patient&#39;s head. The head support may be in the form of a cradle that is coupled with the second support surface  804  using cables, rods, and/or other supports. The supports may be extended and/or retracted to raise and/or lower the cradle. In other embodiments, the head support may include an inflatable pad that contacts a portion of the patient&#39;s head. The pad may be inflated to raise the head and deflated to lower the head. 
     Elevation device  800  may include one or more support mechanisms that are configured to maintain the second support surface at a desired elevation. For example, elevation device  800  may include one or more support posts  806  that are each configured to maintain the second support surface  804  at an elevated position relative to the first support surface  802 . Each support post  806  may be in the form of a kickstand, such as a top board prop of a grand piano that maintains the top board in an open position or like a prop rod that holds an automobile hood open. The support post  806  may be extended or otherwise positioned upward in engagement with an underside of the second support surface  804  to maintain the second support surface  804  at a desired elevation. For example, an underside of the second support surface  804  may include one or more receptacles that are configured to receive and secure an end of the support post  806 . In some embodiments, multiple receptacles may be provided at different positions on the underside of the second support surface  804  such that the support post  806  may be used to elevate the second support surface  804  at various heights/angles. 
     In some embodiments, support post  806  may be hinged. A hinged support post  806  may be lockable in an extended position that allows the second support surface  804  to be raised relative to the first support surface  802  and locked into place. As just one example, a hinge of the hinged support post  806  may be locked in a straight, extended position and/or may include a sleeve that may be positioned over the hinge to prevent the hinge from pivoting, thereby maintaining the second support surface  804  at a desired position. In other embodiments, the support post  806  may be a telescoping pole, such as a rod formed by a number of nesting rods of various diameters. Friction between the rods may act to maintain the second support surface at a desired height. In some embodiments, the telescoping pole may include a lock mechanism, such as a clamp or sleeve that prevents the telescoping pole from contracting under the weight of the individual&#39;s upper body. 
     Other support posts  806  may be in the form of pneumatic and/or hydraulic struts that utilize pressurized fluids to maintain the second support surface  804  at a desired elevation. Each of these support posts  806  may be disengaged to lower the second support surface  804 . For example, one end of a gas strut may be positioned at a pivot point on a base of elevation device  800  while the other end is fixed to an underside of the second support surface  804 . The strut may be extended or contracted as the elevation of the second support surface  804  changes. 
     Depending on the type of support post  806  used, the second support surface  804  may be lowered with or without downward force being applied by an operator of the elevation device  800 . For example, if the support post  806  is in the form of a kickstand, once the kickstand is disengaged, the second support surface  804  may lower under the weight of the patient&#39;s head. In other embodiments, such as those using telescoping, pneumatic, and/or hydraulic support posts  806 , the operator of the elevation device  800  may need to press down on the second support surface  804  to lower it. In some embodiments using pneumatic and/or hydraulic support posts  806 , the second support surface  804  may be lowered by depressurizing the support post  806 , such as by actuating a pressure relief valve. 
     To aid in the raising and lowering of the second support surface  804 , the second support surface  804  may include one or more handles  808 . For example, the handles  808  may be provided on one or more sides of the second support surface  804  and/or along a top edge of the second support surface  804 . It will be appreciated that while described using manual means for elevation, elevation device  800  may be fitted with controllers, motors, threaded rods, lead screws, pneumatic and/or hydraulic actuators, motor driven telescopic rods, other elevation mechanisms, and/or combinations thereof. In some embodiments, the motors may be coupled with a controller or other computing device. The controller may communicate with one or more input devices such as a keypad. This allows a user to select an angle and/or height of the heart and/or head to be raised using the motor and/or other actuator. Additionally, the controller may be coupled with one or more sensors, such as flow and pressure sensors. Sensor inputs may be used to automatically control the motor and angle of the supports based on flow and pressure measurements. A type of CPR and/or ITP regulation may also be controlled using these and/or other sensor inputs. In some embodiments, the electro-mechanical lift mechanisms may include disengagement mechanisms that allow the elevation device  800  to be operated manually. This allows the elevation device  800  to be operable even if a power source for the electromechanical features is unavailable, such as when a battery is dead or when there is no power outlet or other power source available. 
     In some embodiments, the elevation device  800  may include elevation mechanisms that do not require a pivot point. As just one example, the support posts  806  may be raisable arms that are positioned underneath the second support surface  804  at a front and back of the second support surface  804 . The front arms may raise slower and/or raise to a shorter height than the back arms, thus raising a back portion of the second support surface  804  to a higher elevation than a front portion. 
     Oftentimes, the first support surface  802  and/or the second support surface  804  include a mounting site  810  for a chest compression device  812 . The mounting site  810  may allow a chest compression device  812  to be removably and/or permanently attached to the elevation device  800 . The mounting site  810  may be positioned such that when coupled, the chest compression device  812  is disposed in alignment with the patient&#39;s heart and generally perpendicular (within about 5 degrees of perpendicular) with the patient&#39;s chest. In embodiments where the elevation device  800  is configured to elevate the entire upper body of a patient, the mounting site  810  may be on the second support surface  804 . The chest compression device  812  may be configured to repeatedly compress the individual&#39;s chest using manual and/or electro-mechanical force. For example, the chest compression device  812  may include one or more handles that are operably coupled with a plunger. An operator of the chest compression device  812  may grasp the handles and apply downward force to the plunger to compress the patient&#39;s chest. In some embodiments, the chest compression device  812  may be an active compression/decompression device. For example, a suction cup, adhesive pad, and/or other fastening mechanism may be secured to the patient&#39;s chest. The operator may then pull up on the handle to lift the patient&#39;s chest, thereby actively decompressing the chest. 
     Automatic chest compression devices  812  may also be used. For example, automatic chest compression devices  812  may include a reciprocating plunger that may be actuated by a motor, solenoid, and/or other electro-mechanical actuator. In other embodiments, active decompression may be provided to the patient receiving CPR with a modified load distributing band device (e.g. modified Zoll Autopulse® band) by attaching a counter-force mechanism (e.g. a spring) between the load distributing band and the head up device or elevation device  800 . Each time the band squeezes the chest, the spring, which is mechanically coupled to the anterior aspect of the band via an arch-like suspension means, is actively stretched. Each time the load distributing band relaxes, the spring recoils pulling the chest upward. The load distributing band may be modified such that between the band and the anterior chest wall of the patient there is a means to adhere the band to the patient (e.g. suction cup or adhesive material). Thus, the load distributing band compresses the chest and stretches the spring, which is mounted on a suspension bracket over the patient&#39;s chest and attached to the head up device. It will be appreciated that the above chest compression devices are merely provided as examples, and that numerous variants may be contemplated in accordance with the present invention. 
     In some embodiments, the second support surface  804  may be slidable and/or otherwise expandable and contractible lengthwise during elevation of the patient&#39;s upper body to maintain the patient in a correct position and to assist in preventing the patient from curling forward during the elevation process. For example, the second support surface  804  may include multiple pieces that are slidable or otherwise movable relative to one another to expand and contract to maintain the patient in a desired position. This expansion and contraction may be particular useful in embodiments with automatic chest compression devices  812 , as the expansion and/or contraction may be useful in ensuring that chest compressions are delivered at a proper position and angle relative to the patient&#39;s chest. In some embodiments, the second support structure  804  may include an upper section that is slidable along a support frame to permit the thorax to move freely upward and remain elongate, rather than contract, during the elevation process. For example, the upper section may be supported on rollers with minimal friction. As the head, neck, and/or shoulders are lifted, the upper section may slide away from the thoracic compression, which relieves a buildup of pressure on the thorax and minimizes thoracic compression and migration. In some embodiments, the second support surface  804  or a portion thereof may be spring biased in a contraction direction such that the only shifting or expansion of the upper section or other component of the second support surface  804  is due to forces from the individual as the individual is subject to thoracic shift. In other embodiments, the second support surface  804  may be coupled with the first support surface  802  using telescoping rods or supports. These supports may extend and contract to move and/or otherwise adjust a position of the second support surface  804  (and the patient&#39;s head) relative to the first support surface  802 . It will be appreciated by those skilled in the art that other mechanisms may be incorporated to combat the effects of thoracic shift. 
     In some embodiments, intrathoracic pressure management may be used during the administration of chest compressions. For example, an impedance threshold device configured to interface with the individual&#39;s airway may be attached to and/or used in conjunction with the elevation device  800 . 
     In one embodiment, a controller may adjust an actuation speed of a motor or other elevation mechanism to raise or lower an upper support surface of the elevation device within the necessary time frame. For example, medical personnel may set a desired elevation time, such as between about 2 and 30 seconds. The controller will then operate a motor or other elevation mechanism to slowly raise the second support surface  804  from a starting elevation angle to a final elevation angle over the selected time period. The controller may also instruct the elevation mechanism to quickly lower the upper support  804  within a desired timeframe, often between about 1 and 10 seconds. In some embodiments, the controller may receive data from one or more physiological sensors and use this data to determine rates and timing of elevation and lowering. For example, the patient on the elevation device  800  may be monitored using an electrocardiogram (ECG). The ECG may detect a stable heart rhythm even if the individual has no palpable pulse. Based on this detection of the stable heart rhythm, it may be determined to stop the performance of chest compressions and to promptly lower the second support surface  804 . For example, once it is detected that the patient has a stable heart rhythm, the controller may alert medical personnel that chest compressions should be ceased, and may send a signal to the motor or other actuator to cause the second support surface to rapidly lower. In some embodiments, alerting medical personnel may involve producing a visual indicator, such as lighting up a light emitting diode (LED) or other light source and/or presenting a textual and/or image-based display on a screen of the elevation device  800 . In one embodiment, upon detecting a stable heart rhythm, the controller may send a command to the automatic chest compression device  812  that causes the chest compression device  812  to stop the delivery of chest compressions and/or decompressions. In another embodiment, upon detecting the stable heart rhythm, the controller will alert medical personnel, who may then operate the elevation device  800  to lower the second support surface  804 . It will be appreciated that other sensors may be used in conjunction with the elevation device  800  to determine: when to start and/or stop CPR, when to elevate and/or lower a patient&#39;s upper body, a degree of elevation of the patient&#39;s upper body, a rate of elevation or lowering of the patient&#39;s upper body, and/or other parameters of CPR and/or ITPR. 
     In one embodiment shown in  FIG. 9A , an elevation device  900  may be configured to elevate only a portion of the patient&#39;s upper body, including the upper chest/heart, shoulders, and head. Elevation device  900  is similar to elevation device  800  and may include similar features. Elevation device  900  includes a first support surface  902  that is configured to support at least a portion of the upper body, including the heart. Typically, the first support surface  902  extends below the individual&#39;s rib cage, and may extend to support all or a portion of the patient&#39;s lower body. In some embodiments, the first support surface  902  may be generally aligned with a horizontal plane, while in other embodiments the first support surface  902  may be aligned with a plane that is angled slightly above horizontal, such as between about 1 and 5 degrees above horizontal. A second support surface  904  may be configured to support the individual&#39;s shoulders and head, with a pivot point  906  between the first support surface  902  and the second support surface  904  at a position proximate the individual&#39;s rib cage. The second support surface  904  may be pivoted relative to the first support surface  902  to raise the patient&#39;s shoulders and head as shown in  FIG. 9B . Elevation device  900  may include one or more support posts  908  similar to those described in relation to  FIGS. 8A and 8B  that are configured to maintain the second support surface  904  at a desired elevation. The elevation device  900  may also include a mounting site  910  for a chest compression device  912 . The mounting site  910  is typically positioned on the second support surface  904  at a position in general alignment with the patient&#39;s heart. Elevation device  900  may also include one or more handles  914  to assist an operator in raising and/or lowering the second support surface. Elevation device  900  may also include one or more motors, controllers, and/or other lift mechanisms, similar to those described in relation to elevation device  500 . These controllers and lift mechanisms may work in conjunction with the chest compression device  912  to raise and/or lower the patient&#39;s upper body and/or control a rate and/or timing of chest compressions as described in relation to  FIGS. 8A and 8B . 
     In one embodiment shown in  FIG. 10A , an elevation device  1000  may be configured to elevate a portion of the patient&#39;s upper body, including the upper chest/heart, shoulders, and head. Elevation device  1000  is similar to elevation devices  800  and  900  and may include similar features. Elevation device  1000  includes a first support surface  1002  that is configured to support at least a portion of the upper body. Typically, the first support surface  1002  supports at least the patient&#39;s heart, similar to the thoracic plates described elsewhere herein. The first support surface  1002  may be moved between a generally supine position and an elevated position, along with any angles therebetween. The generally supine position may involve the first support surface  1002  being between about 0 and 10 degrees relative to a horizontal plane. The elevated position may have a maximum height of between about 4 cm and 15 cm. A second support surface  1004  may be configured to support the individual&#39;s shoulders and head, with a pivot point  1006  between the first support surface  1002  and the second support surface  1004  being disposed at a position just above the patient&#39;s heart. The second support surface  1004  may be pivoted relative to the first support surface  1002  to raise the patient&#39;s shoulders and head as shown in  FIG. 10B . For example, the second support surface  1004  may be raised to an angle of between about 15 and 45 degrees relative to horizontal while the first support surface  1002  is left in the generally supine position. In some embodiments, both the first support surface  1002  and the second support surface  1004  may be elevated, such as shown in  FIG. 10C . The first support surface  1002  and the second support surface  1004  may be elevated to the same or different angles, typically with the second support surface  1004  being elevated at a larger angle relative to horizontal than the first support surface  1002 . In some embodiments, elevation device  1000  may include a base (not shown) that is coupled with one or both of the first support surface  1002  and the second support surface  1004 . 
     Elevation device  1000  may include one or more support posts  1008  similar to those described in relation to  FIGS. 8A and 8B  that are configured to maintain the first support surface  1002  and/or the second support surface  1004  at a desired elevation. In some embodiments, the support posts  1008  may be configured to rest upon a support surface, while in other embodiments, the support posts  1008  extend between the base and the respective support surface. The elevation device  1000  may also include a mounting site  1010  for a chest compression device  1012 . The mounting site  1010  is typically positioned on the first support surface  1002  at a position in general alignment with the patient&#39;s heart. Elevation device  1000  may also include one or more handles  1014  on the first support surface  1002  and/or the second support surface  1004  to assist an operator in raising and/or lowering the respective support surface. Elevation device  1000  may also include one or more motors, controllers, and/or other lift mechanisms, similar to those described in relation to elevation device  500 . These controllers and lift mechanisms may work in conjunction with the chest compression device  1012  to raise and/or lower the patient&#39;s upper body and/or control a rate and/or timing of chest compressions as described in relation to  FIGS. 8A and 8B . 
     In some embodiments, the elevation devices described herein may be foldable for easy carrying. For example, the elevation devices may be configured to fold up, much like a briefcase, at or near the axis of rotation of the upper support such that the upper support may be brought in close proximity with the thoracic plate and/or base. In some embodiments, the upper support may be parallel or substantially parallel (such as within 10° of parallel) to the base. In some embodiments, an underside of the base and/or upper support may include a handle that allows the folded elevation device to be carried much like a briefcase. In other embodiments, rather than having a fixed handle, the elevation device may include one or more mounting features, such as clips or snaps that allow a handle to be attached to the elevation device for transportation while in the folded state. In some embodiments, a lock mechanism or latch may be included to lock the elevation device in the folded and/or unfolded state. In some embodiments the foldable head and thorax elevation CPR device may be folded up in a briefcase and include an automated defibrillator, physiological sensors, and the like. 
       FIGS. 11A-11L  depict an example of an elevation device  1100 , which may be similar to other elevation devices described herein. This device is designed to be placed under the patient, for example, as soon as a cardiac arrest is diagnosed. It has a low profile designed to slip under the patient&#39;s body rapidly and easily. For example,  FIG. 11A  shows that elevation device  1100  may include a base  1102  that supports and is pivotally or otherwise operably coupled with an upper support  1104 . Upper support  1104  may include a neck pad or neck support  1106 , as well as areas configured to receive a patient&#39;s upper back, shoulders, neck, and/or head. An elevation mechanism may be configured to adjust the height and/or angle of the upper support  1104  throughout the entire ranges of 0° and 45° relative to the horizontal plane and between about 5 cm and 45 cm above the horizontal plane. In some embodiments, the upper support  1104  may be configured to elevate the middle of the patient&#39;s head to a height that is between about 2 and 42 cm above a middle of the heart. In some embodiments, an angle between the middle of the patient&#39;s head and a middle of the heart is between about 10 and 40 degrees relative to horizontal. 
     A user may be positioned on the elevation device  1100  with his neck positioned on the neck support  1106 . In some embodiments, the neck support  1106  may contact the individual&#39;s spine at a location near the C7 and C8 vertebrae. This position may help maintain the individual in the sniffing position, to help enable optimum ventilation of the individual. In some embodiments, the individual may be aligned on the elevation device  1100  by positioning his nipples just above a center line of the back plate  1108 . The chest compression device is coupled with the back plate  1108  such that the chest compression device is in alignment with the individual&#39;s sternum at a generally orthogonal angle to ensure that the chest compressions are delivered at a proper angle and with proper force. In some embodiments, the alignment of the chest compression device may be achieved may configuring the chest compression device to pivot and/or otherwise adjust angularly to align the chest compression device at an angle substantially orthogonal to the sternum. 
     As shown in  FIG. 11A , elevation device  1100  is in a lowered position, with the upper support  1104  being configured to maintain the patient&#39;s head at a position that is slightly elevated relative to the heart, which is supported by back plate  1108 . In the lowered position, a head-receiving portion of the upper support  1104  (which is designed to maintain the patient in the sniffing position and extends downward from a top surface of the upper support  1104 ) maintains the base of the head at a generally horizontal level (within about 5 degrees) when in a fully lowered position. The upper support  1104  may be raised as shown in  FIG. 11B  to elevate the patient&#39;s head, shoulders, and/or heart, which the head being supported at heights of between about 5 cm and 45 cm relative to a horizontal support surface on which the base  1102  is supported. Upper support  1104  may be configured to be adjustable such that the upper support  1104  may slide along a longitudinal axis of base  1102  to accommodate patients of different sizes as well as to accommodate movement of a patient associated with the elevation of the head by upper support  1104 . Without such sliding ability, a patient&#39;s upper body has a tendency to curl forward on the elevation device  1100  as the patient&#39;s upper body is elevated. As shown in  FIG. 11B , the upper support  1104 , including neck support  1106 , are extended away from the back plate  1108  when the upper support  1104  is elevated. In some embodiments, this sliding movement may be locked once an individual is positioned on the elevated upper support  1104 . In some embodiments, the upper support  1104  may include one or more springs that may bias the upper support  1104  toward the torso. This allows the upper support  1104  to slide in a controlled manner when the individual&#39;s body shifts during the elevation process. In some embodiments, the one or more springs may have a total spring force of between about 10 lb. and about 50 lbs., more commonly between about 25 lb. and about 30 lb. Such force allows the upper support  1104  to maintain a proper position, yet can provide some give as the head and upper torso are elevated. Further, the elevation device may include a slide mechanism such that with elevation of the head and neck the portion of elevation device behind the head and shoulder elongates. For example, the slide mechanism may include roller bearings that are mounted on a track that allows the upper support  1104  to slide to accommodate patients of different sizes as well as to handle shifting of the body during elevation, which helps to maintain the neck in the sniffing position. In some embodiments, such as those shown in  FIGS. 11C and 11D , a locking handle  1116  is provided that allows medical personnel to adjust a lateral position of the upper support  1104  relative to the base  1102 . To actuate the handle  1124 , a user must apply force to push a distal portion  1126  of the handle  1124  toward a fixed, proximal portion  1128  of the handle  1116 . This action pushes a locking member (not shown) into a free space of a ratchet mechanism, allowing the user to adjust the lateral position of the upper support  1104 . Once released, the locking member may enter a tooth of the ratchet to set a position of the upper support  1104  based on a size of the user. The upper support  1104  may then only slide in small amounts to handle the shifting of the patient throughout the elevation process. 
       FIGS. 11E and 11F  depict a linear actuator  1120  that is used to raise and lower the upper support  1104 . Linear actuator  1120  is coupled at a joint formed between two or more support members  1122 . Support members  1122  are coupled between the base  1102  and a bottom surface of the upper support  1104  such that top support member(s)  1122  is coupled with the upper support  1104  and the bottom support member(s)  1122  is coupled with the base  1102 . As linear actuator  1120  is operated, a rod  1124  of the linear actuator  1120  shortens to draw the joint of the support members  1122  toward the back plate  1108 , which causes an angled between the top and bottom supper members  1122  to increase, such as shown in  FIG. 11E , forcing the upper support  1104  upward to elevate a patient&#39;s upper body. When operated in reverse, the rod  1124  of linear actuator  1120  extends, pushing on the joint to decrease the angle between the top and bottom support members  1122  as shown in  FIG. 11F , thereby lowering the upper support  1104 . It will be appreciated that the direction of operation of the linear actuator  1120  and support members  1122  may be reversed in some embodiments such that lengthening rod  1124  causes elevation of the upper support  1104  and shortening of rod  1124  causes the lowering of the upper support  1104 . While shown here with a linear actuator  1120  and support member  1122  elevation mechanism, it will be appreciated that elevation device  1100  may additionally or alternatively include other elevation mechanisms, such as threaded rods, lead screws, pneumatic and/or hydraulic actuators, motor driven telescopic rods, other elevation mechanisms, and/or combinations thereof. 
     Turning back to  FIGS. 11A and 11B , the back plate  1108  may be sized and shaped to receive a portion of the patient&#39;s back, just behind the heart and may be configured to couple with a chest compression device (not shown). Examples of CPR assist devices that could be used with the elevation device (either in the current state or a modified state) include the Lucas device, sold by Physio-Control, Inc. and described in U.S. Pat. No. 7,569,021, the entire contents of which is hereby incorporated by reference, the Defibtech Lifeline ARM—Hands-Free CPR Device, sold by Defibtech, the Thumper mechanical CPR device, sold by Michigan Instruments, automated CPR devices by Zoll, such as the AutoPulse, as also described in U.S. Pat. No. 7,056,296, the entire contents of which is hereby incorporated by reference, the Weil Mini Chest Compressor Device, such as described in U.S. Pat. No. 7,060,041 (Weil Institute), and the like. Chest compression devices used in accordance with the present invention may be configured to compress and/or actively decompress the chest. 
     In some embodiments, the back plate  1108  may have a curved profile that may provide some flexibility to the back plate  1108 . This flexibility helps when the elevation device  1100  is used in conjunction with a chest compression device, as the flexibility ensures that the right amount force applied to the patient&#39;s chest. For example, a central portion of the back plate  1108  may flex in the presence of excessive force, thereby absorbing some of the force. For example, as a plunger of a chest compression device is pressed into the patient&#39;s chest, some force is transmitted through the patient to the back plate  1108 . The back plate  1108  may be configured to bend away from the patient if this transferred force exceeds a threshold. This allows for the delivery of compression at the appropriate depth for patients with differing chest wall sizes and stiffness&#39;s. This helps prevent broken ribs and/or other injuries to the patient caused by too much force being applied to the patient&#39;s chest, as the flexing back plate  1108 , rather than the ribs or other body structures, absorbs a significant portion of the excess force. Such a design is particularly useful when the elevation device is used in conjunction with a chest compression device such as the Lucas device, sold by Physio-Control, Inc. and/or the Zoll AutoPulse. 
     In some embodiments, the back plate  1108  that is part of and/or is coupled with the upper support  1104  in such a manner that an angle of the back plate  1108  is adjustable relative to the base  1102  and/or the upper support  1104 . The back plate  1108  may be configured to adjust angularly to help combat thoracic shift to help maintain a chest compression device at a generally orthogonal to the sternum. The adjustment of the back plate  1108  may create a separate elevation plane for the heart, with the head being elevated at a greater angle using the upper support  1104  as shown in  FIG. 11B . In some embodiments, the back plate  1108  may be adjusted independently, while in other embodiments, adjustment of the back plate  1108  is tied to the elevation of the upper support  1104 . For example, a back plate may include a roller (such as a v-groove bearing) positioned on an elevation track formed on or coupled with an underside of an upper support as illustrated in the embodiment discussed in relation to  FIGS. 4G-4J  of U.S. patent application Ser. No. 15/850,827, previously incorporated by reference. The roller may be positioned on a forward, raised portion of the elevation track. As the upper support  1104  is elevated, the roller is forced upward by elevation track, thereby forcing an end of the back plate  1108  proximate to the upper support  1104  upwards. This causes the back plate  1108  to tilt, thus maintaining the chest at a generally orthogonal angle relative to the chest compression device that is coupled with the back plate  1108 . Oftentimes, elevation track may be slanted from a raised portion proximate to the back plate  1108  to a lowered portion. The elevation track may be tilted between about 4° and 20° to provide a measured amount of tilt relative to the thoracic shift expected based on a particular elevation level of the upper support  1104 . Typically, the back plate  1108  will be tilted at a lower angle than the upper support  1104  is inclined. Such simultaneous movement is also demonstrated in  FIGS. 11G and 11H . In  FIG. 11G , the upper support  1104  is in the lowered position and the back plate  1108  is in its original position. In  FIG. 11H , the upper support  1104  is elevated, which has caused the back plate  1108  to have a corresponding forward tilt, which is less that than the degree of elevation of the upper support  1104 . 
     In some embodiments, the back plate may be removably coupled with the base  1102  and/or the upper support  1104 . As shown in  FIG. 11I , a latch  1130  is provided beneath the back plate  1108 . The latch  1130  may be spring biased such that a bottom surface of the latch  1130  is able to receive a back edge of the back plate  1108 . The latch  1130  may be pushed downward with the back plate  1108  secured by a tip of the latch  1130  until a spring-biased pin (not shown) slides along a bottom surface of the latch  1130  and engages with a hole formed within a body of the latch  1130 . The pin secures the latch  1130  in a locked position in which the back plate  1108  is securely coupled with the base  1102  and/or upper support as shown in  FIG. 11J . A release knob  1132  shown in  FIG. 11K  is coupled with the base  1102  and may be used to draw the pin out of the hole formed in the body of latch  1130  to release the back plate  1108 . For example, as shown in  FIG. 11L , release knob  1132  may be coupled to the pin via a flexible cable  1134 , similar to a brake cable on a bicycle. When knob  1132  is pulled, the pin is drawn out of the hole and the spring force can push the latch  1130  into a release position in which the back plate  1108  may be removed from the base  1102 . 
     In some embodiments, the elevation device  1100  may include a number of features that make the device more safe to operate. For example, as seen in  FIG. 11A , elevation device  1100  may include a vinyl (or other natural or synthetic material) cover  1136  that may cover the moving components, such as the motor or actuator and/or slide mechanism. the cover  1136  can extend and retract as the upper support  1104  raises and lowers. For example, cover  1136  may operate in a manner similar to a convertible top for an automobile, and may retract in a compact, accordion style manner when the upper support  1104  is lowered. The upper support  1104  of elevation device  1104  may have a front surface  1140  that is curved in a manner such that as the upper support  1104  raises and lowers the front surface  1140  stays approximately the same distance from the back plate  1108 . In other words, a gap between the two components remains generally constant, which eliminates any possible pinching hazard that could exist due to the relative movement between the two components. 
     In one embodiment, a controller and/or control system may adjust an actuation speed of a motor or other elevation mechanism to raise or lower the upper support  1104  of the elevation device  1100  within the necessary time frame. For example, medical personnel may set a desired elevation time, starting elevation angle, intermediate elevation angle(s), final elevation angle, rate of elevation, etc. The controller will then operate linear actuator  1120 , a motor, and/or other elevation mechanism to slowly raise the upper support  1104  from a starting elevation angle to a final elevation angle over the selected time period. For example, the controller may be configured to elevate the head and thorax may be done in a sequence by 1) elevating the head and thorax over two or more sequential elevation steps and/or 2) elevating the head and thorax over a more prolonged period of time from the start of the elevation to the final height. In some embodiments, the controller may cause the chest compression device to perform CPR for a period of time (between about 30 seconds and 10 minutes, more commonly between about 2 minutes and 8 minutes, and more commonly between about 3 minutes and 6 minutes) while the individual is in a flat, supine position (or nearly supine, such as with the head and/or heart elevated slightly to an angle of less than about 5 degrees relative to horizontal) prior to causing the actuator to elevate the upper support  1104  and the individual to an intermediate and/or final height. In some embodiments where the individual has been primed flat, the controller may perform an additional priming step at an intermediate elevation position prior to elevating the individual to the final/highest elevation position. In other embodiments, the individual may be primed by first elevating the individual&#39;s head and heart to one or more intermediate elevation positions (i.e. between about 10 and 25 degrees) and then performing chest compressions for a period of time prior to elevating the individual&#39;s heart and head to a final elevation position (i.e. between 20 and 45 degrees). Thus, in some embodiments the starting elevation position may range between about 0 and 25 degrees, and more commonly between about 0 and 15-20 degrees. Such starting elevation positions may result in the individual&#39;s heart being at a position of between about 0 cm to 8 cm above horizontal and the individual&#39;s head being at a position of between about 0 and 15 cm above horizontal. The chest compressions may be continued during the elevation adjustment periods after each priming step. 
     The controller may also control the rate of elevation of the upper support  1104 . As just one example, the controller may maintain the elevation speed at a rate of not faster than 1° over each 0.3 second period. The lift speed may be linear and/or non-linear throughout each elevation step. 
     Blood drains rapidly from the head when the patient has no blood pressure and the head and upper body are elevated. As a result, there is a need to lower the head fairly rapidly to prevent blood loss in the brain if CPR is stopped while the head is elevated. Typically, this means that the patient&#39;s head and upper body may be elevated at a different rate than it is lowered. The patient&#39;s head may be lowered by the controller between about 1 and 10 seconds, and typically between about 1-5 seconds. 
     The controller may also be configured to cause the actuator to slowly and continuously raise the upper support  1104  (and individual&#39;s heart, shoulders, and head) from a starting elevation position to a final elevation position. For example, a starting elevation position may include the individual being positioned in a generally flat, supine position (with the head elevated less than 5° relative to horizontal). The individual&#39;s head, shoulders, and heart may be slowly raised (linearly and/or non-linearly) from the starting elevation position to a position where the head is elevated between about 20 and 45 degrees relative to horizontal (an absolute elevation of the heart by about 5-10 cm and an absolute elevation of the head by about 15-25 cm, although these ranges may vary based on the age, size, and/or physiology of a specific individual) over a period of between about 30 seconds and 10 minutes, more commonly between 2 minutes and 8 minutes, and optimally between about 3 minutes and 6 minutes, while CPR is performed. For example, the head, shoulders, and heart may be raised at a rate of between about 2.25°/second and about 1.5°/minute. In other embodiments, an individual may be quickly raised to a starting elevation position of between about 8-15 degrees before slowly elevating the head, shoulders, and heart to a final elevation position over a period of between about 30 seconds and 10 minutes, more commonly between 2 minutes and 8 minutes, and optimally between about 3 minutes and 6 minutes, while CPR is performed. 
     In some embodiments, the controller may receive data from one or more physiological sensors and use this data to determine rates and timing of elevation and lowering. For example, the patient on the elevation device  1100  may be monitored using an electrocardiogram (ECG). The ECG may detect a stable heart rhythm even if the individual has no palpable pulse. Based on this detection of the stable heart rhythm, it may be determined to stop the performance of chest compressions and to promptly lower the upper support  1104 . For example, once it is detected that the patient has a stable heart rhythm, the controller may alert medical personnel that chest compressions should be ceased, and may send a signal to the motor or other actuator to cause the upper support  1104  to rapidly lower. In some embodiments, alerting medical personnel may involve producing a visual indicator, such as lighting up a light emitting diode (LED) or other light source and/or presenting a textual and/or image-based display on a screen of the elevation device  1100 . In one embodiment, upon detecting a stable heart rhythm, the controller may send a command to the automatic chest compression device that causes the chest compression device to stop the delivery of chest compressions and/or decompressions. In another embodiment, upon detecting the stable heart rhythm, the controller will alert medical personnel, who may then operate the elevation device  1100  to lower the upper support  1104 . It will be appreciated that other sensors may be used in conjunction with the elevation device  1100  to determine: when to start and/or stop CPR, when to elevate and/or lower a patient&#39;s upper body, a degree of elevation of the patient&#39;s upper body, a rate of elevation or lowering of the patient&#39;s upper body, and/or other parameters of CPR and/or ITPR. 
     The elevation device  1100  elevates the head above the heart, with the level of elevation optionally varying depending upon the method of CPR. CPR itself is inherently inefficient, providing only about 20% of normal blood flow to the heart and brain. Elevation of the head is not safe during conventional CPR as it is not possible to consistently or safely push enough blood “uphill” to the head to take advantage of the effects of gravity of the venous side of the arterial-venous circuit that is integral to cerebral perfusion. Methods of CPR that generate the most forward flow provide the opportunity to elevate the head above the heart more than those methods that provide less forward flow. For example, active compression decompression (ACD) CPR with an impedance threshold device (ITD) can triple blood flow to the heart and brain compared with conventional manual CPR alone and therefore the head can be elevated higher and still get enough perfusion to take advantage of the effects of gravity with HUP CPR. By contrast, the head should not be elevated as much with conventional CPR and the ITD as forward blood flow without ACD CPR is less, and therefore too much elevation of the head could worsen outcomes. For these reasons the optimal head elevation may vary both depending upon the method of CPR used and the condition of the patient. 
     The relative vertical distance between the head and the heart is important as the amount of pressure needed to “lift” or pump the blood from the heart to the brain is related to this distance. Further, the vertical distance between the head and the heart affects the amount of cerebral perfusion. Although the amount of elevation of the head relative to the heart may vary depending upon the method of CPR (which is the mechanism used to pump the blood), it is generally preferred to have the head elevated relative to the heart by a distance in the range from about 2 cm to about 42 cm. In the specific case where ACD-CPR is being performed with an ITD, the distance may be in the range from about 5 cm to about 25 cm, for standard CPR with an ITD between about 5 cm and about 20 cm, for ACD CPR by itself between about 5 cm and about 20 cm, and with conventional or standard CPR between about 3 cm and about 15 cm. Further, the distance that the heart may be elevated relative to a support surface upon which the lower portion of the patient is resting (such as a table, floor, gurney, stretcher, or the ground) may be in the range from about 2 cm to about 20 cm (with ranges between about 4 cm and 10 cm being common), while the height of the head relative to the support surface may be in the range from about 5 cm to about 45 cm (with ranges between about 10 cm and 40 cm being common). When performing ACD-CPR+ITD, the distance that the heart may be elevated relative to a support surface upon which the patient is resting may be in the range from about 2 cm to about 20 cm, while the height of the head relative to the support surface may be in the range from about 5 cm to about 45 cm. Of course, these relative heights can also be thought of in terms of an angle of elevation of the upper body relative to the lower body when the patient is bent at the waist when performing CPR. Such angles are described herein. Typically, the angle between the patient&#39;s heart and brain is between 10 degrees and 40 degrees relative to horizontal to achieve the necessary elevation, although it will be appreciated that such angles are largely driven by the patient&#39;s physiology (height, distance between head and heart, etc.). 
     In some embodiments the heart will not be elevated. For example, a small head-only elevation device may be used that would only elevate the head, while allowing the heart to remain in the horizontal plane along with the lower body. Such elevation devices may be particular useful when performing CPR without the use of a CPR assist device/automated chest compression device as it reduces the amount of force needed to pump blood to the patient&#39;s brain during CPR. In such cases, the head would be raised to a distance in the range from about 5 to 20 cm relative to the heart (which is not elevated relative to the support surface). 
     In some embodiments, the controller be configured to detect a type of CPR being delivered and may automatically adjust an elevation of the heart and/or head based on the detected level of force. This may be done, for example, by allowing a user to input a type of CPR being performed into the elevation device  1100 . In other embodiments, such as those where a chest compression device is coupled with or formed integrally with the elevation device, the elevation device may communicate with the chest compression device to determine if the chest compression device is being used to deliver compressions and/or an amount of force being delivered and may make any necessary elevation adjustments based on this data. In other embodiments, one or more physiological sensors may be used to detect physiological parameters, such as cerebral perfusion pressure, intrathoracic pressure, and the like. This sensor data may be used to determine a compression force and/or otherwise determine how high to elevate the head and heart. 
     It should be noted that the elevation devices/head up devices (HUD) could serve as a platform for additional CPR devices and aids. For example, an automatic external defibrillator could be attached to the HUD or embodied within it and share the same power source. Electrodes could be provided and attached rapidly to the patient once the patient is place on the HUD. Similarly, ECG monitoring, end tidal CO 2  monitoring, brain sensors, a defibrillator, and the like could be co-located on the HUD. In addition, devices that facilitate the cooling of a patient could be co-located on the HUD to facilitate rapid cooling during and after CPR. 
     In addition or alternatively to one or more of the techniques described above, in some embodiments, the chest compression device will be coupled to a device to elevate the head and thorax that includes one or more support restraints (such as straps, belts, rods, cloth strips, and the like) to stabilize the patient on the elevation device. 
     It should be further noted that during the performance of CPR the compression rate and depth and force applied to the chest might vary depending upon whether the patient is in the flat horizontal plane or whether the head and thorax are elevated. For example, CPR may be performed with compressions at a rate of 80/min using active compression decompression CPR when flat but at 100 per minute with head and thorax elevation in order to maintain an adequate perfusion pressure to the brain when the head is elevated. Moreover, with head elevation there is better pulmonary circulation so the increase in circulation generated by the higher compression rates will have a beneficial effect on circulation and not “overload” the pulmonary circulation which could happen when the patient is in the flat horizontal plane. 
     It will be appreciated that some embodiments may utilize simplified elevation devices. For example, an elevation device may include only a base an upper support, and an actuator for raising and lowering the upper support relative to the base. The upper support may have one or more generally planar surfaces, with one or more of the surfaces optionally being contoured to match a shape of a patient&#39;s back. Additionally, the curved profile may make the support surface flexible. This flexibility helps when the elevation device  1100  is used in conjunction with a chest compression device, as the flexibility ensures that the right amount force applied to the patient&#39;s chest. For example, a central portion of the upper support may flex in the presence of excessive force, thereby acting as a flexible back plate to absorb some of the force. For example, as a plunger of a chest compression device is pressed into the patient&#39;s chest, some force is transmitted through the patient to the upper support. The upper support may be configured to bend away from the patient if this transferred force exceeds a threshold. This allows for the delivery of compression at the appropriate depth for patients with differing chest wall sizes and stiffness&#39;s. This helps prevent broken ribs and/or other injuries to the patient caused by too much force being applied to the patient&#39;s chest, as the flexing back plate, rather than the ribs or other body structures, absorbs a significant portion of the excess force. Such a design is particularly useful when the elevation device is used in conjunction with a chest compression device such as the LUCAS device, sold by Physio-Control, Inc. and/or the Zoll AutoPulse and/or devices that combine the concepts underlying the load-distributing band in the AutoPulse and automated active compression decompression (ACD) as in the LUCAS. However, it will be appreciated that the flexible upper support may be used in conjunction with any of the embodiments of elevation devices described herein. It should be appreciated that the portion of the elevation device under the heart and thorax could also contain force, pressure, impedance, and/or position sensors to provide feedback to the chest compression device, assuring the proper compression depth and force are delivered, even though the amounts needed to provide the proper CPR may differ from patient to patient and may change over time. In some embodiments, the chest compression device may be coupled with the elevation device  1100  in such a manner that compressive and/or decompressive force from the chest compression device remains generally perpendicular (within 5 degrees) to the patient&#39;s sternum at all elevation positions. 
     In some embodiments, the patient&#39;s upper body may be elevated at a same angle on a single surface of the upper support, while in other embodiments the upper support may have two or more generally planar surfaces that elevate the heart and head at different angles relative to horizontal. The actuator may be manual and/or automatically driven with operating controls that enable the upper support to be to be raised and lowered in a controlled manner necessary to perform sequential elevation as described herein. For example, the elevation device may be fitted with controllers, motors, threaded rods, lead screws, pneumatic and/or hydraulic actuators, motor driven telescopic rods, other elevation mechanisms, and/or combinations thereof. In some embodiments, the motors may be coupled with a controller or other computing device. The controller may communicate with one or more input devices such as a keypad. This allows a user to select an angle and/or height of the heart and/or head to be raised using the motor and/or other actuator, along with a rate of elevation or other timing element of the elevation process. Additionally, the controller may be coupled with one or more sensors, such as flow and pressure sensors. Sensor inputs may be used to automatically control the motor and angle of the supports based on flow and pressure measurements. A type of CPR and/or ITP regulation may also be controlled using these and/or other sensor inputs. In some embodiments, the electro-mechanical lift mechanisms may include disengagement mechanisms that allow the elevation device to be operated manually. This allows the elevation device to be operable even if a power source for the electromechanical features is unavailable, such as when a battery is dead or when there is no power outlet or other power source available. 
     In some embodiments, the upper support may define an opening that is configured to receive a portion of a patient&#39;s head. This opening may help maintain the patient in the sniffing position for optimal airway management. Oftentimes, a head support may be included on the upper support. It will be appreciated that in some embodiments the head support may extend around the entire opening. The head support may be formed of contoured padding, such as foam padding, such that patients having heads of different sizes and shapes may be supported adequately by the single head support. 
     In some embodiments, the chest compression device and the elevation device may share a common power source. For example, the chest compression device or the elevation device may include a power source, such as a power cord and/or battery. The non-powered device may then plug into the other device to share the power source. In other embodiments, the chest compression device and the elevation device may be formed as a single device, with the elevation mechanism of the elevation device and the chest compression device both being wired to a single power source. 
     In some embodiments, the chest compression device and elevation device may be configured to communicate with each other. For example, one or more network or other data cables and/or wireless interfaces may couple processors and/or sensors of each device to one another. Data regarding elevation height, speed of elevation, speed of declination, CPR rate, force applied to the patient, and/or other data may be measured and shared between the devices. Additionally, data from physiological sensors may be shared with the elevation device and/or the chest compression device. This physiological data, such as ICP, blood flow data, blood pressure, intrathoracic pressure measurements, and the like may be used to control the various parameters such as elevation timing, elevation angle, chest compression depth and/or force, and the like. 
     Additionally, the chest compression device and/or elevation device may be configured to communicate with other devices, such as computers, mobile devices like mobile phones and tablet computers, e-readers, other medical equipment, such as electrocardiographs and defibrillators, and the like. To enable such communication, one or more wired and/or wireless communication networks may be established. For example, various data cables may be used to communicatively couple the chest compression device and/or elevation device to one or more remote devices. In some embodiments, the chest compression device and/or elevation device may include a wireless communications interface that is configured to communicate with one or more remote devices using WiFi, Bluetooth, 3G, 4G, LTE, and/or other wireless communications protocols. 
     In some embodiments, the elevation device may be coupled with a stretcher-like device for transport that has features that allow the heart and head to be elevated above the plane of the abdomen and lower extremities. For example, the stretcher or stretcher-like device may include rails or other rigid or semi-rigid support members that may be used to secure the elevation device and/or the chest compression device to the stretcher. The elevation device and/or the chest compression device may be coupled to the support members using clamps cables, and/or other securement mechanisms that may ensure the elevation device and/or the chest compression device do not shift relative to the stretcher. 
     In some embodiments, the elevation device may include a stowable shelf (not shown). The stowable shelf may be configured to be maintained in a stowed position in which most or all of the shelf is disposed within an interior of the elevation device, with only a handle and/or outer surface of the stowable shelf remaining exposed exteriorly of the elevation device. The stowable shelf may be extended outward into an extended position in which all or a large portion of the stowable shelf protrudes from a side of the wedge  1100 . This protruding portion may be used by medical personnel as a support for their knees so that the rescuer may be elevated relative to the ground and positioned properly for administering CPR. For example, the stowable shelf may be configured to elevate the rescuer to a height of between about 2 and 4 inches relative to the ground. Oftentimes, the stowable shelf may be positioned on a roller track or other sliding mechanism that enables the stowable shelf to be manipulated between the stowed position and the extended position. 
     Oftentimes it may be beneficial to gather data related to actual cases where CPR was performed. To gather this data, the elevation devices and/or intrathoracic pressure regulation devices may include sensors that are configured to measure and record various data related to the performance of CPR. Additional sensors and devices may also be used in conjunction with the elevation devices and/or intrathoracic pressure regulation devices to gather relevant data. Oftentimes this data may serve as feedback that drives various aspects of the CPR process. This data may also be useful in further advancing the science behind HUP CPR techniques, as well as to provide training data to help medical personnel learn and perfect the necessary techniques. 
     The elevation devices described herein are used to reduce brain injury and brain swelling. As just one example,  FIG. 12  depicts a process  1200  for reducing brain injury and brain swelling. Process  1200  may be performed using any of the elevation devices described herein. Process  1200  may begin by performing active compression decompression cardiopulmonary resuscitation (ACD-CPR) on an individual while the individual is in a supine position in general alignment with a horizontal plane at block  1202 . At block  1204 , the individual&#39;s head, shoulders, and heart may be elevated relative to the individual&#39;s lower body while the individual&#39;s lower body remains generally aligned with the horizontal plane. The head may be elevated to a height of between about 10 cm and 30 cm above the horizontal plane and the heart may be elevated to a height of between about 1 cm to 10 cm or 2 cm and 10 cm above the horizontal plane. The individual&#39;s chest may be compressed and actively decompressed while the individual&#39;s head, shoulders, and heart are elevated at block  1206 . At block  1208 , the intrathoracic pressure of the individual may be regulated using an impedance threshold device or other ITPR device both while the individual is in the supine position and while the individual&#39;s head, shoulders, and heart are elevated relative to the lower body, thereby reducing brain edema during CPR. 
     In some embodiments, head up CPR may be used in combination with a technique to reduce reperfusion injury. For example, prior to performing ACD-CPR on the individual, chest compressions may be performed on the individual for a period of between about 20-40 seconds. After performing the chest compressions on the individual and prior to performing ACD-CPR on the individual, halting the performance of chest compressions on the individual for a period of between about 20-40 seconds. By incorporating several of these rounds of supine chest compressions followed by halting the performance of chest compressions, reperfusion injury may be reduced. For example, the supine chest compressions followed by halting the performance of chest compressions on the individual may be repeated between 2-5 times prior to performing ACD-CPR to further reduce the risk of edema and brain swelling. 
     In some embodiments, upon stopping the performance of CPR, the individual may be maintained in a head up position with the individual&#39;s head, shoulders, and heart elevated as long as a sufficient mean arterial pressure (or blood pressure) is maintained to support blood flow to the brain in the head up position. For example, a sufficient mean arterial pressure to maintain adequate blood flow to the brain may be between about 60 mm Hg and 70 mm Hg. Such additional time in the head up position may further prevent brain edema and swelling. 
     The multiple methods and devices described above reduce brain swelling and elevated brain pressures during and after CPR. In the clinical setting of a patient with brain injury not in cardiac arrest, ICP is used to determine if a given therapy is effective in reducing brain swelling. For example, when the ICP is measured with an intracranial bolt, levels above 15 mmHg are generally considered dangerous and numerous approaches are used to treat such patients. These may include removing spinal fluid through the intracranial bolt, treatment with mannitol or hypertonic saline, hypothermia, hyperventilation to reduce CO2 in the blood which secondarily constricts of the arterial blood vessels to the brain (when brain autoregulation is intact), use of an intrathoracic pressure regulator to generate negative intrathoracic pressure following a positive pressure during mechanical ventilation, and elevation of the head. A reduction in ICP by even 2-4 mmHg is considered clinically important since the brain damage associated with elevated ICP is exponential due to the fact the brain is in a confined space. As the brain swelling rises there is no place for the brain tissue to go. In the most extreme cases the brain tissues herniates through the foramen magnum, the hole that connects the spinal column and cord to the brain. 
     In some embodiments, upon commencing CPR, therapeutic hypothermia and/or other cooling techniques may be performed to further reduce brain edema. For example, cooling of the individual may be done intravascularly and/or intraosseously with iced saline, or equivalent cooling through the nose, lungs, veins, and/or esophagus, with one of a variety of means and solutions that would work synergistically to reduce brain swelling and damage associated with cardiac arrest. This cooling may be performed during and/or after the performance and/or conclusion of CPR. 
     Example 1 
     The following experiments were performed to demonstrate that the methods and devices in this patent reduce brain edema during CPR and after resuscitation. The studies demonstrate that ICP, the measurement that is used clinically to determine whether or not the brain swelling, and cerebral oximetry, the non-invasive measure of brain oxygen, both improve clinically when the invention is used. The studies were performed as follows: 
     Female Yorkshire farm pigs weighing between 36-44 kg were fasted overnight after acclimatizing in the animal care facility for at least three days. Intramuscular ketamine (10 mL of 100 mg/mL) was administered in the holding pen. The animals were then transferred to the surgical suite where they were treated with inhaled isoflurane at 1% to 2.5% for anesthesia. The animals were then intubated with a 7.5 French endotracheal tube and ventilation was performed using a ventilator (Narkomed, North American Dräger, Telford, Pa.) with tidal volume 10 mL/kg. ETCO2 and oxygen saturation were recorded with a CO2SMO Plus® (Novametrix Systems, Wallingford, Conn.). The respiratory rate and FiO2 were adjusted to keep oxygen saturation above 92% and ETCO2 between 37 and 43 mmHg. Intravenous (IV) access with an 18-gauge catheter was obtained through a lateral ear vein. All animals received room air temperature normal saline bolus of 1000 ml during preparatory phase to maintain the mean right atrial pressure between 4 and 7 mmHg. Temperature was monitored with an esophageal probe. Temperature was maintained between 36.5 and 38.5° C. using a warming blanket, as needed. This Methodology was fully described in an article entitled, “Head and thorax elevation during active compression decompression cardiopulmonary resuscitation an impedance threshold device improves cerebral perfusion in a swine model of prolonged of cardiac arrest” by Johanna C Moore MD, Nicolas Segal MD PhD, Michael C Lick BA, Kenneth W Dodd MD, Bayert J Salverda BA, Mason B Hinke BA, Aaron E Robinson MD MPH, Guillaume Debaty MD PhD, and Keith G Lurie MD. to be published in Resuscitation in 2017. Intracranial pressure (ICP) was measured by creating a burr hole in the skull, and then insertion of a micromanometer-tipped catheter (Mikro-Tip Transducer, Millar Instruments, Houston, Tex.) catheter into the parietal lobe. All animals received a 100 units/kg bolus of heparin intravenously every hour. 
     Data were recorded continuously using the BioPac computer system (BioPac; BioPac Systems Inc, Goleta Calif.). When the preparatory phase was complete and the animal was hemodynamically stable, isoflurane was discontinued, and after 3 minutes ventricular fibrillation (VF) was induced with delivery of direct electrical current from a pacing wire placed in the right ventricle. ACD CPR+ITD was performed with an automatic piston device (Pneumatic Compression Controller; Ambu International, Glostrup, Denmark) or with a LUCAS 2 device that pulls up only 3 pounds during the decompression phase (Physio-control, Redmond Wash.). ACD CPR was performed at a rate of 80 compressions/min, with a 50% duty cycle and depth of 22.5% of antero-posterior chest diameter, and the chest was pulled upwards after each compression with a suction cup on the skin at a decompression force of approximately 10 kg. The LUCAS 2 compressed at 100 compressions/min. An ITD, (ResQPOD-16, Zoll Medical, Minneapolis, Minn.) was placed at the end of the endotracheal tube in all studies. The HUP CPR device used in this study elevated just the head and shoulders and upper thorax 30° such that the heart and head heights were ˜5 and ˜25 cm above the horizontal plane, respectively, as shown in  FIGS. 13A and 13B . 
     While transitioning from supine to the HUP CPR was performed in an uninterrupted manner. During CPR, positive pressure ventilation was delivered with oxygen, titrated to a SpO2 of ≥92%, with a tidal volume of 10 mL/kg. If the animal was noted to gasp during the resuscitation, time at first gasp was recorded. Succinylcholine was administered at a dose of 3 mg (0.075/kg) to inhibit gasping after the third gasp. 
     Regional Cerebral oximetry saturation (rSO2) was measured with an INVOS™ regional oximetry probe (Metronic-Covidien) applied to the pig&#39;s forehead. The approach uses near infrared spectroscopy to assess rSO2. Data were measured and recorded continuously as described above. 
     Experimental Protocol 
     After 8 minutes of untreated VF, ACD CPR+ITD or LUCAS 2+ITD was performed with a 30:2 compression: ventilation ratio, and positive pressure ventilation with room air was provided while all pigs were in the supine position (SUP) to simulate basic life support. After 2 minutes of CPR, animals were randomized either HUP CPR or SUP CPR and continuous asynchronous CPR+ITD was continued for 18 minutes with a 10:1 compression: ventilation ratio to simulate advanced life support. After 19 total minutes of CPR, 0.5 mg of adrenaline was administered intravenously followed by 25 mg of amiodarone. One minute later, pigs were defibrillated with up to three 200 J biphasic shocks (X-series, Zoll Medical, Chelmsford Mass.). Animals were monitored and were euthanized with an intravenous injection of KCl 20 minutes later. 
     ICP measurements were made from 3 sequential compression-decompression cycles between positive pressure breaths. These values were averaged for each of the compression-decompression cycle measurements for each time point in each animal study. Data are expressed as mean values. 
     Eighteen female pigs weighing 39.5±8.2 kg were randomized to ACD+ITD CPR in HUP (n=8) or SUP (n=10). ICP (mmHg) was measured in one pig from each group 15 minutes after successful resuscitation. Pigs treated with HUP ACD+ITD CPR had significantly lower intracranial pressure (ICP) after 15 minutes of ACD CPR+ITD and after 15 minutes return of spontaneous circulation (ROSC) and successful resuscitation versus SUP. These findings are shown in Table 1 below. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 ICP after 15 min. CPR 
                 ICP post ROSC 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 CPR flat or supine 
                 17.7 
                 22.6 
               
               
                 CPR Head and thorax elevated 
                 7.7 
                 8.3 
               
               
                   
               
            
           
         
       
     
     Two sets of studies with cerebral oximetry as the main endpoint were performed with the protocol described above to demonstrate the importance of the invention: one was performed using the LUCAS 2 that provides up to 3 pounds of upward force and the other with the ACD device that provides up to 20 pounds of decompression force. 
     As shown in  FIG. 14  with the LUCAS 2+ITD devices to provide CPR, the regional cerebral oximetry saturation values were highest with the head and thorax elevated during and after successful resuscitation with the lowest values when the head and thorax flat during CPR and after resuscitation. The unit of the Y-axis is regional cerebral oxygen saturation. Similar findings were observed with the ACD+ITD device that pulls upwards with 20 pounds of force during the active decompression phase as shown in  FIG. 15 . Taken together, these studies show that elevation of the head and thorax during and after CPR results in less brain edema, as measured by ICP, compared with pigs treated with CPR in the flat or horizontal plane. This is reflected in the normal ICP values when treatment is head and thorax elevation during CPR and after resuscitation. Similarly, cerebral oxygen saturation levels in pigs treated with elevation of the head and thorax during and after CPR were normal versus much lower when CPR was performed in the flat position and the pigs were kept flat after resuscitation. 
     With CPR performed with the body in the flat position, which is the standard of care throughout the world today, the ICP values during CPR and after resuscitation were nearly twice as high as those treated with head and thorax elevation. Similarly, the cerebral oxygen levels were normal after resuscitation with head and thorax elevation versus much lower in pigs treated with flat CPR. 
     These studies demonstrate the invention is effective to reduce brain edema as measured by ICP and cerebral oxygenation and also demonstrate that the head and thorax needed to be elevated during CPR and after resuscitation. Moreover, elevation of the head and thorax either just during CPR or just after resuscitation was not sufficient to restore normal brain oxygen levels or maximally reduce brain edema after resuscitation. It should be noted the invention reduces brain swelling after resuscitation, and it can be used synergistically with all other drugs, devices, methods, and techniques that are known to lower ICP and brain swelling to optimize long-term neurological outcomes after cardiac arrest. It should also be restated that the head and thorax can only be safely elevated after successful resuscitation to optimize the benefits of the invention if the mean arterial pressure is sufficient to pump blood up to the brain, typically it should be at least ˜65 mmHg. This can be maintained, if necessary, with the aid of pharmacological agents such as adrenaline and the like. 
     A reduction in intracranial pressure (ICP), recognizing that measurement of ICP is a means to directly assess the pressure within the brain that is also highly correlated with brain edema, occurs immediately upon elevation of the head during cardiac arrest. This new observation is shown in  FIG. 16 . In this figure, all pressures are measured in mmHg. The top pressure tracing, labeled ITP, is the intrathoracic pressure, the second pressure tracing labeled AO is aortic pressure, the third RA is right atrial pressure, the fourth ICP is intracranial pressure, the fifth is the calculated coronary perfusion pressure (AO-RA) and the sixth is the calculated cerebral perfusion pressure (Ao-ICP). 
     What is shown in this representative tracing from pigs in cardiac arrest as described above, is that after a period of untreated cardiac arrest, in this case 8 minutes, elevation of the head by 10 cm while this pig is being placed from the horizontal flat position onto a head up CPR device as shown in  FIG. 16 , (at the time point of 4795 seconds on the graph), there is an immediate reduction in ICP by 5 mmHg whereas the aortic pressure remains constant. The results of the effect of gravity are shown: ICP falls and the cerebral perfusion pressure rises, simply with elevation of the head and thorax onto the elevated CPR device shown in  FIG. 6 . By reducing ICP, even before starting CPR, the likelihood of brain damage and brain edema is reduced. 
     In general brain edema can result from prolonged periods of no flow and trauma to the brain. The prolonged periods of reduced blood flow to the brain associated with CPR performed on the body when in the flat or horizontal plane combined with the concussive forces from the arterial and venous pressure wavefronts that bombard the brain with each chest compression result severe brain edema in ⅓ of patients who arrive at the hospital alive. Such patients rarely, if ever, wake up. By contrast, elevation of the head and thorax, as described within this application, results in an immediate reduction in ICP, even before starting CPR as shown in  FIG. 16 . Head up applications are also described in U.S. application Ser. No. 15/986,466, U.S. application Ser. No. 15/601,494, U.S. application Ser. No. 15/285,063, U.S. application Ser. No. 15/160,492, U.S. application Ser. No. 15/133,967, U.S. application Ser. No. 14/996,147, U.S. application Ser. No. 14/935,262, U.S. application Ser. No. 14/677,562, 2015, U.S. Provisional Application No. 61/941,670, U.S. Provisional Application No. 62/000,836, and U.S. Provisional Application No. 62/087,717, and U.S. Provisional Application No. 62/242,655, the complete disclosures of which are hereby incorporated by reference for all intents and purposes), the entire contents of which are hereby incorporated by reference, These applications demonstrate that elevation of the head and heart during CPR result in a marked reduction in ICP and a marked increase in cerebral and coronary perfusion and perfusion pressures. By reducing the overall ischemic burden (lack of blood flow to the brain and heart) with head and thorax elevation, and reducing the trauma from the ‘concussion with every compression’, the likelihood of brain edema is reduced. This is also shown by the lower ICP values in the pigs treated with head up CPR compared with flat CPR during and after resuscitation (as shown in Table 1 above).