Abstract:
A method of inhibiting hypotensive symptoms in a patient undergoing treatment or a procedure involves elastically constraining the internal organs within the abdomen of the patient while applying non-pulsating, compressive pressure to the internal organs within the abdomen of the patient. The method may also involve one or more of infusing fluid, applying the compressive pressure using compression device, or applying the compressive pressure based upon bio-indicator measurement parameters.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of U.S. patent application Ser. No. 12/062,944, filed Apr. 4, 2008, which, in turn claims the priority benefit of U.S. Provisional Patent Application No. 61/000,436, filed Oct. 26, 2007, the disclosures of both of these applications are incorporated herein by reference in their entirety. 
    
    
     FIELD 
     This application relates generally to medical devices and procedures, and more particularly, to medical devices, procedures and treatments used during hemodialysis or on a critical care patient. 
     BACKGROUND 
     Patients suffering from renal failure of the kidneys are often treated using hemodialysis procedures to remove excess fluid and metabolic wastes (e.g., urea, creatinine, etc.) accumulated in body tissue and blood. During hemodialysis, a patient&#39;s blood is shunted from the body through a hemodialysis machine for diffusion and ultrafiltration before being returned to the patient&#39;s circulation system. Hemodialysis treatments are typically performed three or perhaps four times per week on a patient having chronic renal failure, with each session lasting between three to five hours. 
     Patients undergoing hemodialysis treatment are prone to suffer from hypotensive (low blood pressure) symptoms, such as headache, dizziness, muscle cramping and vomiting. Despite the many improvements made to modern hemodialysis procedures, intradialytic hypotension in hemodialysis patients continues to be a major source of concern for the well being of the patient. Many hemodialysis patients experience chronic hypotension, which is abnormal decrease in the patients&#39; blood pressure. For some of these patients, the intradialytic hypotensive symptoms are so severe that they cannot tolerate the hemodialysis procedure and must instead resort to peritoneal dialysis or renal transplant. Indeed, repeated development of these hypotensive symptoms is a key factor leading to the high mortality rate of hemodialysis patients. 
     For many hemodialysis patients, it is believed that the intradialytic hypotensive symptoms result from the pooling of blood within the internal organs in the abdominal area or waist of the hemodialysis patient. Some have proposed use of an inflatable abdominal band to improve orthostatic hypotension, which is associated with a decrease in systolic blood pressure when patients change from supine to standing position. For instance, N. Yamamoto et al., Treatment of post-dialytic orthostatic hypotension with an inflatable abdominal band in hemodialysis patients, K IDNEY  I NTERNATIONAL,  70:1793-1800 (Sep. 27, 2006), discloses use of an inflatable abdominal band to treat patients, who after their hemodialysis treatment, are suffering from post-dialytic orthostatic hypotension. H. Tanaka et al., Treatment of orthostatic intolerance with inflatable abdominal band, T HE  L ANCET,  349:175 (Jan. 18, 1997), discloses use of an inflatable abdominal band to treat orthostatic hypotension in patients with orthostatic intolerance. A. Smit et al., Use of lower abdominal compression to combat orthostatic hypotension in patients with autonomic dysfunction, C LIN  A UTON  R ES  14:167-175 (2004), discloses use of an elastic abdominal binding to increase standing blood pressure in patients with neurogenic orthostatic hypotension. J. Deng et al., Efficacy of compression of different capacitance beds in the amelioration of orthostatic hypotension, C LINICAL  A UTONOMIC  R ESEARCH  7, 321-326 (1997), discloses use of compression garments such as an antigravity suit (G suit) in treating patients with chronic symptomatic orthostatic hypotension. 
     Other types of compressive devices are known in the art. For instance, U.S. Pat. No. 4,925,133 entitled “Hydraulic Buoyancy Force Suit” discloses a buoyancy force suit to reduce pooling of blood with the goal of maintaining consciousness of flying pilots. U.S. Pat. No. 4,534,338 entitled “Servo Operated Anti-G Suit Pressurization System” discloses a servo operated system for quickly pressurizing an aircraft pilot&#39;s anti-G suit during high energy maneuvers. U.S. Pat. No. 4,938,208 entitled “Full Length Compressible Sleeve” discloses a sleeve for applying compressive pressure against a patient&#39;s limb to prevent pooling of blood in a patient&#39;s limb. Similarly, arterial pressure sphygmomanometers include an inflatable compression band worn about a patient&#39;s arm to identify diastolic and systolic arterial pressure. Non-inflatable work wear or belts that wrap around a person&#39;s waist are used to reduce the load on the back by providing additional support for the spine. 
     None of these references, however, address treatment of intradialytic hypotension occurring during the hemodialysis treatment. It is, therefore, desirable to reduce the pooling of blood in the abdominal organs of the patient during hemodialysis treatments in order to eliminate the development of intradialytic hypotensive symptoms over the course of hemodialysis. 
     Patients in critical care may also encounter similar problems resulting from trauma or burns. Reducing the pooling of blood in the abdominal organs of such critical care patients can lead to more effective fluid and blood infusion and improve cardiac filling to enhance cardiovascular functions of these seriously ill patients. Therefore, it is also desirable to reduce the pooling of blood in the abdominal organs of critical care patients to make fluid or blood infusion more effective in improving cardiac filling to enhance cardiovascular functions. 
     SUMMARY 
     One aspect of the disclosure involves a method of increasing venous return in a hypotensive patient in critical care suffering from blood or fluid loss. The method involves elastically constraining the abdomen of the patient while a) concurrently maintaining mobility of the patient&#39;s legs and applying non-pulsating compressive pressure to the internal organs within the abdomen of the patient according to a predefined protocol, and b) infusing a volume of fluid into the patient&#39;s bloodstream, such that pooling of blood within the patient&#39;s abdominal internal organs and distribution of the infused volume in the abdominal organs are both reduced. 
     Another aspect of the disclosure involves a method of inhibiting hypotensive symptoms in a patient undergoing a procedure. The method involves elastically constraining the abdomen of the patient throughout the procedure while concurrently maintaining mobility of the patient&#39;s legs; and applying non-pulsating, gradually increasing compressive pressure to the internal organs within the abdomen of the patient during the procedure with an elastic vest having multiple discrete elastic bands affixed thereto, each of the discrete elastic bands having a free end wherein the total number of free ends comprises at least three free ends, the elastic vest including multiple markings thereon to denote compression levels that will be applied when the free ends are releasably affixed to the elastic vest near the markings, the constraining thereby reducing the pooling of blood within the patient&#39;s abdominal internal organs while concurrently allowing for unencumbered movement of the patient&#39;s legs during the procedure. 
     Yet another aspect of the disclosure involves a further method of inhibiting hypotensive symptoms in a patient undergoing a procedure. The method involves elastically constraining the abdomen of the patient throughout the procedure while concurrently maintaining mobility of the patient&#39;s legs and applying non-pulsating, compressive pressure to the internal organs within the abdomen of the patient according to a predefined protocol during the procedure, the protocol including monitoring bioimpedance of the abdominal organs of the patient and the patient&#39;s blood density, thereby reducing the pooling of blood within the patient&#39;s abdominal internal organs while concurrently allowing for unencumbered movement of the patient&#39;s legs during the procedure. 
     These aspects and advantages arising from the present disclosure will be apparent to those of ordinary skill in the art by reference to the following detailed description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an example compression/anti-pooling vest worn around the waist of a patient in accordance with the present disclosure; 
         FIG. 1A  illustrates the dial of a pressure gauge utilized with the compression vest illustrated in  FIG. 1 ; 
         FIG. 2  is a plan view of the inner surface of one example embodiment of the compression vest illustrated in  FIG. 1 ; 
         FIG. 2A  is a perspective view illustrating the outer surface of the compression vest shown in  FIG. 2 ; 
         FIG. 3  is a plan view of the inner surface of another example embodiment of the compression vest; 
         FIG. 3A  is a perspective view illustrating the outer surface of the compression vest shown in  FIG. 3 ; 
         FIG. 4  illustrates an inflatable bladder utilized with the compression vest illustrated in  FIG. 1 ; 
         FIG. 4A  illustrates the configuration of the inflatable bladder, tubing, manual pressurization system and pressure gauge utilized with the compression vest illustrated in  FIG. 1 ; 
         FIG. 5  is a graph illustrating manual pressurization of the compression vest over time during a hemodialysis treatment; 
         FIG. 6  is a schematic diagram of an automatic pressurization controller for pressurizing or depressurizing the inflatable bladder of the compression vest; 
         FIG. 7  illustrates an example display on an automatic pressurization controller for the compression vest; 
         FIG. 8  is a graph illustrating pressurization of the compression vest over time by an automatic pressurization controller during a hemodialysis treatment; 
         FIG. 9  is a plan view of the inner surface of a further example embodiment of the compression vest; 
         FIG. 9A  is a perspective view illustrating the outer surface of the compression vest of  FIG. 9 ; 
         FIG. 10  is a simplified view of an optional pad and its cross section that can be inserted into an optional pocket of the compression vest; 
         FIG. 11  is a simplified view of yet an additional alternative implementation of a compression vest as described herein. 
     
    
    
     DETAILED DESCRIPTION 
     An anti-pooling/compression wear or vest  10  is disclosed herein for preventing the pooling of blood or other fluids in the organs within the abdomen or waist of a patient. The vest  10  may be used for a variety of medical purposes, including, but not limited to, countering the development of intradialytic hypotensive symptoms in patients undergoing hemodialysis and/or improving cardiac filling to enhance cardiovascular functions in critical care patients suffering from trauma or burns. As used herein, the terms “treatment” and “procedure” are used interchangeably and intended to interchangeably mean any or all of these as well as dealing with or preventing hypotensive symptoms in general. This disclosure also includes methods and protocols to pressurize the patient&#39;s abdominal organs to one or more preset or predetermined pressures during and after the treatment, designs of the vest  10  to best-fit patient&#39;s abdominal contour, and safety features of the vest  10  for the patient&#39;s well being. 
     Vest with Manual Operation 
       FIG. 1  illustrates an example of the anti-pooling/compression wear or vest  10  worn around the waist or abdomen of a patient. The vest  10  includes a flexible band  20  and an inflatable bladder  30  with tubing  32  that may be pressurized using a manual pressurization system  40 . An automatic pressurization system, such as the system described further below and illustrated in  FIGS. 6-8 , may be substituted for the manual pressurization system  40 . 
     A patient is illustrated in  FIG. 1  squeezing a manual pump or bulb  40  to increase pressure in the inflatable bladder  30 , which is located within the vest  10 . The pressure within the inflatable bladder  30  is displayed on a pressure dial or gauge  50 , which is shown in  FIG. 1  as being held in the patient&#39;s other hand. A dial  50   a  of the pressure gauge  50  is illustrated in  FIG. 1A . The dial  50   a  includes a plurality of markings indicative of pressure in, for example, mm Hg, with a region  52   a  of the markings being highlighted to indicate that pressure above a preset or predetermined maximum threshold (e.g., above 30 mm Hg) for use with the anti-pooling vest  10 . To ensure proper use of the vest  10 , instruction labels may be provided on the vest  10 , as well as a nametag for the patient and/or health care professional to write the patient&#39;s name. 
     One example embodiment of the band  20  is illustrated in  FIGS. 2 and 2A . The band  20  is flexible so that it can be wrapped about the abdomen or waist of the patient. The band  20  is typically made of nylon, such as, for example, polyurethane coated 420d Nylon fabric (420D/PU2 Nylon). Alternatively, the band  20  may be made from other suitable non-stretchable fabrics. The band  20  may be, for example, approximately eight to ten inches wide and approximately 55 inches in length. The size of the band, its material and its color may be modified to fit the need or preference of the patient. 
     The inner or back surface  20   a  of the band  20  is illustrated in  FIG. 2 . This is the surface  20   a  that contacts the patient when the band  20  is wrapped about the abdomen or waist of the patient as illustrated in  FIG. 1 . A webbing trim  22 , such as, for example, a ⅞ inch polypropylene (PP) webbing trim, may be provided around the edges of the band  20 . The inner surface  20   a  of the band  20  includes an area  23  provided with a plurality of fasteners, such as Velcro® brand hook fasteners, for releasably engaging corresponding fasteners, such as Velcro® brand loops  24   a ,  24   b , located on the front surface  20   b  of the band  20 . 
     The front or outer surface  20   b  of the band  20  is illustrated in  FIG. 2A . The outer surface  20   b  is the surface of the band  20  that is exposed when the band is wrapped about the abdomen or waist of a patient as illustrated in  FIG. 1 . The outer surface  20   b  includes an area  24   a ,  24   b  containing a plurality of fasteners, such as Velcro® brand loops. When the band  20  is wrapped about the abdomen or waist of a patient with the inner surface  20   a  in contact with the patient as is shown in  FIG. 1 , the band may be releasably held in place by bringing the area  23  containing the plurality of hook fasteners into contact with the corresponding loops in the area  24   a  on the outer surface  20   b  of the band. It is understood that the arrangement of hook and loop fasteners may be reversed so that the loop fasteners are arranged in area  23  and the hook fasteners in area  24   a ,  24   b.    
     The band  20  also includes one or more elastic bands or strips  25 ,  26 , each strip having one end that is sewn or otherwise affixed to the outer surface  20   b  of the band  20  and an opposing end that is free from the outer surface. A fastener  25   a ,  26   a , such as one part of a Velcro® brand hook and loop fastener, is connected to the free end of each of the elastic strips  25 ,  26 . Each elastic strip  25 ,  26  is between about 1.75 and about 3 inches wide. In the embodiment illustrated in  FIGS. 2 and 2A , the band  20  includes three spaced apart, elastic strips  25  having their free end with the fastener  25   a  extending in the direction of area  24   a  and three spaced apart, elastic strips  26  having their free end with the fastener  26   a  extending in the direction of area  24   b . The use of three pairs of elastic strips  25 ,  26  makes the band  20  more closely conform to the body contour of the patient for more effective compression of internal organs and provides a greater safety margin for the patient not to be overly compressed. It is understood, however, that the use of three pairs of elastic strips  25 ,  26  is exemplary and that the band may incorporate a greater number or lesser number of elastic strips  25 ,  26  than illustrated in the drawings. 
     As discussed above, the band  20  is first wrapped about the abdomen or waist of a patient to enclose most of the patient&#39;s internal organs. The band  20  is releasably held in place by bringing the area  23  containing the plurality of hook fasteners into contact with the corresponding loops in the area  24   a  on the outer surface  20   b  of the band. To better conform the band  20  to the contour of the patient&#39;s waist, the free end of each elastic strip  25  is stretched in the direction of area  24   a  and the free end of each elastic strip  26  is stretched in the direction of area  24   b . When sufficient tension is placed on each strip to better conform the band  20  to the contour of patient&#39;s waist, then the elastic strips  25 ,  26  are releasably connected to the band by engaging the hook fasteners  25   a ,  26   a  on the free ends of the strips with the corresponding loop fasteners located in the areas  24   a  and  24   b  on the outer surface  20   b  of the band. 
     The band  20  also may include a pouch or pocket  27  having an opening  27   a  through which the inflatable bladder  30  inserted for placement within the pocket  27 . Alternatively, the inflatable bladder  30  may be an integral part or otherwise built into the band  20 . In this embodiment, the opening  27   a  is approximately five inches in length and the pocket  27  is approximately 19 inches in length to accommodate a 16 inch by seven inch inflatable bladder  30 . The inside of the pocket  27  is typically made from nylon, such as, for example, polyurethane coated 210d Nylon fabric (210D/PU2 Nylon). When the vest  10  is properly fitted on the patient and the inflatable bladder  30  in the pocket  27  is pressurized, the elastic straps  25 ,  26  and Velcro® brand hook and loop fasteners ensure uniform pressure compression of the patient&#39;s internal organs. 
     Another example embodiment of the band  20 ′ is illustrated in  FIGS. 3 and 3A . The band  20 ′ is similar to the band  20  illustrated in  FIGS. 2 and 2A , with the exception that two strips  23   a ,  23   b  of fasteners, such as Velcro® brand hook fasteners, are provided in the area  23 . These strips  23   a ,  23   b  may be affixed to the band  20 ′ in a conventional manner, such as, for example, by sewing and/or using an adhesive. When the band  20 ′ is wrapped about the abdomen or waist of a patient with the inner surface  20   a  in contact with the patient as is shown in  FIG. 1 , the band may be releasably held in place by bringing the two strips  23   a ,  23   b  of hook fasteners into contact with the corresponding loops in the area  24   a  on the outer surface  20   b  of the band. The construction and operation of the band  20 ′ is similar to the band  20  described above in all other material respects. 
     An example inflatable bladder  30  is illustrated in  FIG. 4 . The bladder  30  is typically made of flexible polyvinyl chloride (PVC), rubber or other impermeable materials that can be inflated without air leakage. As discussed above, the bladder  30  is inserted through the opening  27   a  in the band  20 ,  20 ′ to fit snugly to the pocket  27 . Alternatively, the bladder  30  may be an integral part or otherwise built into the band  20 . The bladder  30  may be, for example, a PVC sheet of 16 inches by fourteen folded to form a dimension of 16 inches by seven inches with three sides heat sealed. Other configurations of the bladder  30  may also be used with the anti-pooling vest  10 . Hollow, flexible tubing  32  extends from the bladder  30  to provide a fluid conduit to the pressurization system, pressure gauge and optional alarm. 
       FIG. 4A  illustrates an exemplary configuration of the inflatable bladder  30 , tubing  32 , manual pressurization system  40  and pressure gauge  50  utilized with the vest  10 . The manual pressurization system includes a bulb or manual pump  40 , a pressure release valve  40   a , a pressure gauge  50 , and an optional alarm (not shown). As illustrated in  FIG. 1 , the tubing  32  from the inflatable bladder  30  is joined through a T-joint or other connector to the tubing  32  connected to the bulb  40  and pressure gauge  50 . The functions of these components are described next. 
     When the pressure release control valve  40   a  of the bulb or manual pump  40  is set to the closed position, the repeated hand squeeze of the bulb by the patient or health care professional causes the bladder  30  to inflate to a predetermined, preset or desired pressure level as indicated by the pressure gauge  50 . By turning the control valve  40   a  to the open position, the pressurized air in bladder  30  is released and the pressure in the bladder can return to zero. A one-way control valve  40   b  at the distal opening or air inlet of the bulb  40  only permits ambient air to enter the bulb  40  and flow from the bulb  40  as it is squeezed through the pressure release control valve  40   a  to inflate the bladder  30 . When the bulb  30  is relaxed and returns to its normal configuration, air is allowed to flow through the one-way valve  40   b  from the atmosphere to fill up the bulb. 
     The pressure gauge  50  displays the pressure in the bladder  30 , which corresponds to the pressure being imposed on the internal organs of the patient when the anti-pooling vest  10  is worn by the patient. A safety pressure release valve (not shown) may be incorporated into the pressure gauge  50  or elsewhere in the pressurization system to limit the maximum pressure that can be imposed by the anti-pooling vest  10  on the patient&#39;s waist and internal organs. Normally, the maximum pressure to inflate the bladder  30  would not exceed 20 mm Hg. Accordingly, the safety pressure release valve could be set to automatically open and release pressure in the bladder  30  that exceeds, for example, 30 mm Hg or 40 mm Hg. 
     An optional alarm may also be used with the vest  10  to make an audible sound at preset or predetermined time intervals to remind the health care professional and/or patient that it may be time to adjust the inflation pressure of the bladder  30  according to, for example, the pressurization protocols described herein. 
     Manual Pressurization and Depressurization Protocol 
     Prior to starting the hemodialysis treatment, the vest  10  is placed about the abdomen or waist of the patient in the manner described above. Once the hemodialysis process is initiated with the patient, one course of pressurization of the inflatable bladder  30  will be a step increase of the pressure by about 3 to 5 mm Hg every half an hour of treatment. 
     Two illustrative examples of manual pressurization protocols are illustrated in  FIG. 5 . The first manual pressurization protocol illustrated in  FIG. 5  is for a hemodialysis treatment period of approximately 2.5 hours. Prior to commencing hemodialysis treatment, the bladder  30  worn about the patient&#39;s abdomen or waist is inflated to a predetermined or preset pressure of about 5 mm Hg by manually squeezing the bulb or pump  40  and the pressure is maintained at this level for about 30 minutes. The pressure in the bladder  30  is then increased to a second predetermined or preset pressure of about 9 mm Hg by manually squeezing the bulb or pump  40  and maintained at this level for about 30 minutes. After about an hour of treatment, the pressure in the bladder  30  is again increased to a third predetermined or preset pressure of about 12 mm Hg by manually squeezing the bulb or pump  40  and maintained at this level for another 30 minutes. After about 1.5 hours of treatment, the pressure in the bladder  30  is again increased to a fourth predetermined or preset pressure of about 16 mm Hg by manually squeezing the bulb or pump  40  and maintained at this level for 30 minutes. After about two hours of treatment, the pressure in the bladder  30  is increased to a fifth predetermined or preset pressure of about 20 mm Hg by manually squeezing the bulb or pump  40  and maintained at this pressure until the 2.5 hour treatment is completed. Once the 2.5 hour treatment period is completed, the patient continues to wear the pressurized anti-pooling vest  10  for at least 30 minutes to an hour. During this time, the pressure in the bladder  30  is gradually reduced to zero using the pressure relief valve  40   a  to allow the blood volume in the patient&#39;s internal organs to gradually return to desirable levels without hypotension. Thereafter, the depressurized vest  10  may be removed from the patient. 
     The second manual pressurization protocol illustrated in  FIG. 5  is for a hemodialysis treatment period of approximately three hours. Prior to commencing hemodialysis treatment, the bladder  30  worn about the patient&#39;s abdomen or waist is inflated to a predetermined or preset pressure of about 5 mm Hg by manually squeezing the bulb or pump  40  and the pressure is maintained at this level for about 30 minutes. The pressure in the bladder  30  is then increased to a second predetermined or preset pressure of about 7.5 mm Hg by manually squeezing the bulb or pump  40  and maintained at this level for about 30 minutes. After about an hour of treatment, the pressure in the bladder  30  is again increased to a third predetermined or preset pressure of about 10 mm Hg by manually squeezing the bulb or pump  40  and maintained at this level for another 30 minutes. After about 1.5 hours of treatment, the pressure in the bladder  30  is again increased a fourth predetermined or preset pressure of to about 12.5 mm Hg by manually squeezing the bulb or pump  40  and maintained at this level for 30 minutes. After about two hours of treatment, the pressure in the bladder  30  is increased to a fifth predetermined or preset pressure of about 15 mm Hg by manually squeezing the bulb or pump  40  and maintained at this pressure for 30 minutes. After about 2.5 hours of treatment, the pressure in the bladder  30  is again increased to a sixth predetermined or preset pressure of about 17.5 mm Hg by manually squeezing the bulb or pump  40  and maintained at this level for 30 minutes. After about three hours of treatment, the pressure in the bladder  30  is increased to a seventh predetermined or preset pressure of about 20 mm Hg by manually squeezing the bulb or pump  40  and maintained at this pressure until the 3.5 hour treatment is completed. Once the 3.5 hour treatment period is completed, the patient continues to wear the pressurized vest  10  for at least 30 minutes to an hour. During this time, the pressure in the bladder  30  is gradually reduced to zero using the pressure relief valve  40   a  to allow the blood volume in the patient&#39;s internal organs to gradually return to desirable levels without hypotension. Thereafter, the depressurized vest  10  may be removed from the patient. 
     Vest with Automatic Operation 
     The vest  10  may also be utilized with an automatic, programmable pressurization/depressurization system. A schematic diagram of an example automatic, programmable system for pressurizing or depressurizing the inflatable bladder  30  of the vest  10  is illustrated in  FIG. 6 . The bladder  30  in the vest  10  may be inflated to predetermined, preset or desired pressures during and after the treatment in accordance with pressurization/depressurization protocols that correspond to the length of treatment and maximum desired pressure that have been selected by the physician and/or health care professional. The band  20 ,  20 ′ and inflatable bladder  30  in the vest with automatic operation is identical in all material respects to that of the vest  10  described above with manual operation. 
     In the example embodiment illustrated in  FIG. 6 , the inflatable bladder  30  in the vest  10  worn about the patient&#39;s abdomen or waist is connected by tubing or conduit  32  to an air pump  350 , a depressurization valve  310 , and a pressure sensor/gauge  300 . A four way joint, pipe connector or other conventional fitting  360  may be utilized to facilitate fluid connection of the pump  350 , depressurization valve  310 , and pressure sensor/gauge  300 . The pump  350  is an electric pump that is powered by a pump power supply  320  and capable of generating sufficient air pressure to inflate the bladder  30  to the desired inflation pressure. When the pump  350  and depressurization valve  310  are not activated, no communication occurs between the joint  360  and atmosphere. For increased safety to ensure that the patient is not overly compressed by the automatic pressurization system, the pump  350  and its associated power supply  320  should have the characteristic that the maximum deliverable pressure at zero flow is less than a preset or predetermined value. 
     The automatic pressurization/depressurization system also includes a controller  100  for controlling the pump  350  (and associated pressurization of the bladder  30 ) and the depressurization valve  310  to automatically achieve the desired pressurization/depressurization protocol, which will be discussed below with respect to  FIG. 8 . The controller  100  includes a processor  200  (e.g., central processing unit (“CPU”), a memory  205  (e.g., random access memory (“RAM”) and/or read only memory (“ROM”)), and a storage device  210  (e.g., hard disk drive, compact disk drive, etc.). Various input/output devices are connected to the processor  200 , such as a display  115 , start switch  105 , timer  110 , treatment period setting switch  120 , maximum pressure setting switch  125 , and pressure sensor/gauge  300 . 
     A display  115  on the automatic pressurization controller  100  for the vest  10  is illustrated in  FIG. 7 . The controller  100  includes a start switch  105 , treatment period setting switch  120 , and maximum pressure setting switch  125 . The physician or health care professional can activate the controller  100  and turn power on to all units in the controller by depressing the start switch  105 . 
     Prior to starting the hemodialysis treatment using the automatic pressurization system, the vest  10  is placed about the abdomen or waist of the patient in the manner described above. The physician or other health care professional can select the treatment period for pressurization of the inflation bladder  30  by moving the selector switch  120  to the desired time interval (e.g., 2.5 hours, 3.0 hours, 3.5 hours, etc.). Similarly, the physician or other health care professional can select the maximum pressure to inflate the bladder  30  by moving the selector switch  125  to the desired maximum pressure (e.g., 15 mm Hg, 20 mm Hg, 30 mm Hg, etc.). It is understood that the number and value of the selector switch positions illustrated in  FIG. 7  are exemplary and that this disclosure is not intended to be limited to the specific switch or a specific number of positions and/or values associated with those positions illustrated in the drawings. 
     The processor  200  is pre-programmed with a pressurization/depressurization protocol for each combination of time interval and maximum pressure settings of the switches  120 ,  125 . Exemplary pressurization/depressurization protocols are discussed further below with respect to  FIG. 8 . 
     The display  115  displays the current time, the time in treatment T, and the actual measured pressure P in the inflatable bladder  30  as measured by the pressure sensor/gauge  300 . The timer  110  keeps the current time and records the time in treatment T, which information is communicated to the processor  200  and is also displayed on the display  115 . 
     The processor  200  derives the pressure P in the inflatable bladder  30  (without the oscillation associated with respiration) by averaging the pressure output from the pressure sensor/gauge  300 . This ensures that pressure fluctuation due to the patient&#39;s breathing is removed. The pressure sensor/gauge  300  measures the actual pressure P in the inflatable bladder  30  and sends a signal associated with the measured pressure P to the processor  200  to determine when to activate the pump  350  and/or depressurization valve  310 . The processor  200  executes the pre-programmed pressurization/depressurization protocol to adjust the pressure P in the inflatable bladder  30  based on the elapsed treatment time T input from the timer  110 , the actual pressure P input from the pressure sensor/gauge  300 , and the selected treatment period and maximum pressure settings from the switches  120 ,  125 . 
     If the actual pressure P measured by the pressure sensor/gauge  300  is below the desired pressure, as determined by the pre-programmed pressure protocol, then the processor  200  activates the pump power supply  320  to drive the pump  350  to inflate the bladder  30 . When the actual pressure P measured by the pressure sensor/gauge  300  reaches the desired pressure according to the pressure protocol, then the processor  200  deactivates the pump power supply  320  to turn the power off to the pump  350 . As a safety feature, the voltage from the power supply  320  can be limited to not exceed a predetermined or preset voltage so that the pressure generated by the pump  350  cannot exceed a predetermined or preset pressure threshold, which is typically a maximum pressure P of 30 mm Hg. 
     When the elapsed treatment time T measured by the timer  110  exceeds the preset treatment time according to the selected setting of the switch  120 , the processor  200  activates the depressurization valve  310  by transmitting a signal to the solenoid on the depressurization valve to open the valve and slowly depressurize the inflatable bladder  30  by venting or otherwise releasing air from the bladder to atmosphere. 
     Four exemplary automatic pressurization/depressurization protocols are illustrated in  FIG. 8  to show the time course of the pressure to inflate the bladder  30  and thus to generate compression to the patient&#39;s abdominal organs. The four exemplary protocols are for a selected maximum pressure of 20 mm Hg for hemodialysis treatment times of 2.5 hours, three hours, 3.5 hours and four hours, respectively. The protocols illustrate a predetermined or preset increase in pressurization of the inflatable bladder  30  over time up to the maximum desired pressure and then the gradual decrease in pressure in the inflatable bladder for at least 30 minutes following the expiration of the hemodialysis treatment time. It is understood that the predetermined or preset inflation pressures correspond to the length of treatment and maximum desired pressure selected by the physician or other health care professional. 
     A higher compression pressure will reduce the blood volume in the patient&#39;s abdominal organs for the improvement of venous return, which will subsequently increase cardiac filling and cardiac output for the alleviation of hypotensive symptoms. 
     Because the improved venous return will lead to better cardiac filling and subsequently higher cardiac output, the improved cardiovascular functions may allow the physician to prescribe a higher rate of ultrafiltration for the patient during the course of hemodialysis. In this way, the hemodialysis treatment time may be reduced for the removal of the same volume of excess fluid that had been accumulated in the body tissue over the time between the previous hemodialysis treatment and the current one. 
     Once the patient completes the hemodialysis treatment, the patient would still wear the anti-pooling vest for the depressurization process. This process will allow the patient&#39;s cardiovascular system to adjust to the depressurization and to minimize the potential for blood to rapidly pool back to the abdominal organs and subsequently the development of hypotensive symptoms. 
     The physician could also prescribe the use of vest  10  for home hemodialysis. Its use can shorten the time required to complete home hemodialysis and to reduce the incidence on the development of hypotensive symptoms. 
     Operation of the Vest for Patients with Trauma or Burns in Hospital&#39;s Critical Care Units 
     Because of blood or fluid loss though trauma or burns, these patients are often hypotensive and require infusion of a volume of fluid or blood. Some of the infused fluid or blood volume tends to expand the microcirculation and/or the macrocirculation. It is the latter that would determine the filling of the heart chambers. More cardiac filling would enable the non-damaged heart to increase cardiac output to deliver more blood flow to important organs. With better blood flow, the patient has a better and speedier chance for recovery. During the hypotensive stage, whether in trauma or during hemodialysis, blood vessels may autoregulate for dilatation to allow more blood to flow through the vessel. Advantageously, use of the vest  10  in conjunction with infusion can be used to improve cardiac filling and make the volume expansion more effective for the alleviation of hypotension and/or shock. 
     Contrary to conventional thinking, this combination approach treats the abdominal organs as being the reason why fluid infusion alone is less effective in countering hypovolemia, hypotension and low cardiac output. Thus, the physician may prescribe the use of the vest  10  for patients capable of accepting abdominal compression to counter the dilatation of blood vessels within the internal organs within the waist or abdomen of the patient for the improvement of venous return during fluid infusion. As a result, the infused blood volume would become more effective to increase venous return, cardiac filling and subsequently cardiac output for the betterment of cardiovascular functions in critical care patients and patients in shock. Similarly, fluid infusion can be used during hemodialysis if the use of the vest  10  alone cannot adequately mitigate the intradialytic hypotension. Thus, by infusing a volume of fluid into the patient&#39;s bloodstream while the vest  10  is applying compressive pressure to the patient&#39;s abdominal internal organs, pooling of blood within the patient&#39;s abdominal internal organs and distribution of the infused volume in the abdominal organs will both be reduced. 
     A low arterial pressure or low total blood volume is an indication of poor cardiovascular function. The larger the pressurization to be provided by the anti-pooling vest, the greater the shifting of blood from the internal organs toward the heart. Accordingly, the physician may select the level of pressurization to be inversely proportional to either the arterial blood pressure or the total blood volume of the patient. 
     The physician may order the use of appropriate medication, such as the use of vasoconstrictor eye drops or intra-muscle injection, to further complement the anti-pooling function of the vest  10 . 
     Non-inflatable Configurations 
     Another alternative example embodiment of the vest includes an alternative band  20 ″ as illustrated in  FIGS. 9 and 9A . This example embodiment of the band  20 ″ is not inflatable and is, or includes portions, that are stretchably elastic so that it can be wrapped about the abdomen or waist of the patient and different degrees of stretch can be used to apply differing levels of compressive force to the internal abdominal organs. 
     In order to accommodate different size and girth people, the band  20 ″ can be provided in different sizes. Table 1 below shows representative example dimensions for the band to accommodate different sized people. It is believed that four sizes should be sufficient for most instances, however, it should be understood that a greater or lesser number of sizes can be used. Note that the columns labeled “a,” “b,” “c,” “d” and “h” correspond to the similarly labeled dimensions in  FIGS. 9 and 9A  (not to scale) with the distances under column “a” denoting the locations of marks to be described below. In this example, the total length of any given size band  20 ″ is 6a+2b+c+d for which “a” indicates the distance between edges of the indicator markings and hence it is associated with the % stretching of the elastic band, the distances “b” generally establish the relaxed length of the band, with the location between the two distances “b” denoting a “central” portion  102  of the band  20 ″, which may or may not be the actual center of the band  20 ″. The segments “c” and “d” are of suitable length to provide for reasonable overlapping and wrapping around the waist or abdomen, with the central portion  102  ideally being placed so that it is essentially centered on the lower back. Example dimensions for multiple sizes of two different example implementations for each are also tabulated in Tables 1 and 2. Note that, although Tables 1 and 2 each illustrate four sizes: small, medium, large and extra large, the use of fewer, greater numbers of sizes or other size ranges are a matter of design choice, the important aspect being the ability to provide the particular levels of compression. In that regard, the values of “a” and “b” are selected so that the pressure imposed to patients of various waist size is comparable when the bands are stretched to the specified markings 
     
       
         
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Patient Waist 
                 Total Band 
                 Number 
                   
                   
                   
                   
                   
               
               
                 Band Size 
                 Size 
                 Length 
                 of Strips 
                 a 
                 b 
                 c 
                 d 
                 h 
               
               
                   
               
             
             
               
                 Small 
                 24″~28″ 
                 33.5″ 
                 3 
                  1.25″ 
                 7″ 
                 2″ 
                 10″ 
                 6″     
               
               
                 Medium 
                 29″~34″ 
                 38.5″ 
                 3 
                 1.5″ 
                     7.5″ 
                     3.5″ 
                 11″ 
                 7″     
               
               
                 Large 
                 35″~41″ 
                 45″     
                 3 or 4 
                 2″     
                 8″ 
                 4″ 
                 13″ 
                 7.5″ 
               
               
                 Extra Large 
                 42″~48″ 
                 52″     
                 3 or 4 
                 2.5″ 
                 9″ 
                 6″ 
                 13″ 
                 8.5″ 
               
               
                   
               
             
          
         
       
     
     
       
         
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                   
                 Patient Waist 
                 Total Band 
                 Number 
                   
                   
                   
                   
                   
               
               
                 Band Size 
                 Size 
                 Length 
                 of Strips 
                 a 
                 b 
                 c 
                 d 
                 h 
               
               
                   
               
             
             
               
                 Small 
                 20″~26″ 
                 29.5″ 
                 3 
                 1″      
                     4.5″ 
                 3.5″ 
                 11″ 
                 6″ 
               
               
                 Medium 
                 27″~33″ 
                 37″     
                 3 
                 1.75″ 
                 6″ 
                 3.5″ 
                 11″ 
                 7″ 
               
               
                 Large 
                 34″~40  
                 44.5″ 
                 3 or 4 
                 2.5″  
                 7″ 
                 3.5″ 
                 12″ 
                     7.5″ 
               
               
                 Extra Large 
                 41″~47″ 
                 51″     
                 3 or 4 
                 3.25″ 
                 8″ 
                 3.5″ 
                 12″ 
                 8″ 
               
               
                   
               
             
          
         
       
     
     The inner or back surface  20 ″ a  of the band  20 ″ is illustrated in  FIG. 9 . This is the surface  20 ″ a  that contacts the patient when the band  20 ″ is wrapped about the abdomen or waist of the patient as illustrated in  FIG. 1 . A trim  22  of suitably stretchable material similar to that illustrated in  FIGS. 2 and 3  may be provided around the edges of the band  20 ″. 
     The front or outer surface  20 ″ b  of the band  20 ″ is illustrated in  FIG. 9A . The outer surface  20 ″ b  is the surface of the band  20 ″ that is exposed when the band is wrapped about the abdomen or waist of a patient as illustrated in  FIG. 1 . The outer surface  20 ″ b  can similarly include areas  24   a ,  24   b  such as shown in  FIGS. 2A and 3A , that contain either the hooks or loops portion of Velcro® brand hook and loop fasteners. For simplicity, those aspects are not shown in  FIG. 9  or  9 A, as they would essentially be the same as shown in  FIG. 2A  or  3 A. The band  20 ″ also includes multiple indicator markings  92 ,  94 ,  96 ,  98 , which will be described in greater detail below. The band  20 ″ is applied by wrapping it about the abdomen or waist of a patient with the inner surface  20 ″ a  in contact with the patient as is shown in  FIG. 1 . Depending upon the particular implementation, other types of fasteners can be used with, or as an alternative to, the hook and loop fasteners, for example, any bra type clasps or other type of mating fastener capable of holding the strips as intended can be used. 
     The band  20 ″ also includes narrow, elastic strips. Depending upon the particular implementation of this band  20 ″, the discrete elastic strips can be paired such that there are actually at least three to five individual strips (typically paired and facing opposite directions from the center of the band  20 ″) with one end of each strip having one end that is sewn or otherwise affixed to the outer surface  20 ″ b  of the band  20 ″ and an opposing end that is free from the outer surface. Alternatively, the discrete individual strips may be configured with the middle of each affixed to band  20 ″ and both ends of each strip being free ends. As shown in  FIGS. 9 and 9A , there are six individual strips, three  25 ″ facing in one direction and the other three  26 ″ facing in the opposite direction. 
     A fastener  25 ″ a ,  26 ″ a , such as either the complementary hooks or loops side of a Velcro® brand hook and loop fastener, is connected to each free end  100  of each of the elastic strips  25 ″,  26 ″ for connection to the two areas  24   a ,  24   b  of the band  20 ″ that is illustrated and described for  FIGS. 2A and 3A  and present in band  20 ″, but omitted from  FIG. 9A  for simplicity. Each elastic strip  25 ″,  26 ″ is typically approximately between one and two inches wide. In the embodiment illustrated in  FIGS. 9 and 9A , the band  20 ″ includes six individual discrete elastic strips  25 ″,  26 ″ with fasteners on each of the free ends  100 . The use of at least three elastic strips  25 ″,  26 ″ makes the band  20 ″ more closely conform to the body contour of the patient for more effective compression of internal organs and provides a greater safety margin for the patient not to be overly compressed. It is understood, however, that the number of strips shown in  FIG. 9  is exemplary and that the band  20 ″ may incorporate a greater number of strips or, in some variants, a lesser number of elastic strips. 
     In addition, the band  20 ″ includes multiple indicator markings  92 ,  94 ,  96 ,  98  located successively closer and closer to the ends of the band  20 ″. The indicator markings are placed so as to denote various levels of compression. Depending upon the particular implementation, the indicator markings may be lines, areas that are contrasted in some manner from adjacent areas (for example, by ribbons, color, printed markings or different textures), or even differing materials. The first indicator marking  92 , located in this example closest to and on either side of the central portion  102  of the band  20 ″ is a neutral marking that is used to denote an area where the band  20 ″ will be constrained about the abdomen, but will exert substantially no compressive pressure (i.e., less than about 4 mm Hg). Moving in a direction away from the central portion  102  of the band  20 ″, the next indicator marking, on either side of the exterior of the band  20 ″ in this example, is a “LowComp” marking  94 , which is used to denote an area where, when the band  20 ″ is about the abdomen of a patient and the strips  25 ″,  26 ″ are affixed in this vicinity, a low compressive pressure will be applied, the pressure generally being in or about equivalent to pressure within the range of about 5 mm Hg to about 12 mm Hg, and nominally centered at a pressure in the range of between about 8 mm Hg and 10 mm Hg, with the ideal being at about 10 mm Hg. 
     Continuing in a direction away from the central portion  102  of the band  20 ″, the next indicator marking is a “MidComp” marking  96 , used to denote an area where affixation of the strips  25 ″,  26 ″ will cause application to the patient of medium compressive pressure, generally in or about equivalent to pressure within the range of about 13 mm Hg to about 22 mm Hg, and nominally centered at a pressure in the range of between about 15 mm Hg to 20 mm Hg, with the ideal being at about 15 mm Hg. 
     Continuing further in a direction away from the central portion  102  of the band  20 ″, the next indicator marking is a “HiComp” marking  98 , which is used to denote the area where the highest or maximum compressive pressure would be applied to the abdomen, at a value generally in or about equivalent to pressure within the range of about 23 mm Hg to about no more than 30 mm Hg, and nominally centered at a pressure in the range of between about 25 mm Hg and 27 mm Hg, with the ideal being at about 25 mm Hg. 
     Alternatively, depending upon the particular materials used, in some cases, the band  20 ″ may be configured such that, for example, a single size band encompasses two or more of the size bands referred to in Table 1 above. In such a case, because the neutral mark location would be different with each, the band  20 ″ may include multiple sets of indicator markings and/or appropriately marked, length-adjustable, strips  25 ″,  26 ″ so that the proper pressure will be applied when the strips  25 ″,  26 ″ are affixed near the specified marks on different sized patients. 
     Similarly, the band  20 ″ may be configured with additional or alternative indicator markings denoting different ranges or levels of compression, the particular style or method of denoting the various compression levels being unimportant provided that the LowComp, MidComp and HiComp levels are indicated in some fashion. In addition, in many instances, it may be undesirable to allow imposition of a compressive pressure equivalent to in excess of about 30 mm Hg. Thus, with most single size embodiments, the band  20 ″ will typically not be configured to allow the strips  25 ″,  26 ″ to be affixed to the band in a location much beyond the HiComp indicator marking or where such excessively high compression would be applied. 
     Advantageously, because narrow strips are used, the patient or the health care personnel should be able to more easily pull each strip to the area of the highest compression force indication marking In addition, by using a greater number and thinner strips than are conventionally used on simple support belts or vests, better conformation to the waist contour can be achieved so that the compression can be more uniformly applied to the abdominal organs. 
     As discussed above, the band  20 ″ is first wrapped about the abdomen or waist of a patient to enclose most of the patient&#39;s internal abdominal organs. The band  20 ″ is then releasably held in place by stretching the strips  25 ″,  26 ″ so as to bring the free ends of the strips  25 ″,  26 ″ near the indicator marking most appropriate for the desired pressure, the location typically being based upon the specific protocol being followed. The fasteners on the end of the strips  25 ″,  26 ″ are then affixed to the band  20 ″ in the vicinity of the selected indicator marking by releasably engaging the fasteners  25 ″ a ,  26 ″ a  with the corresponding fasteners located in the areas  24 ″ a  and  24 ″ b  on the outer surface  20 ″ b  of the band. If the strips  25 ″,  26 ″ are affixed in the area of a particular indicator marking and it is necessary or desired to change the compression to a different level, the free ends of the strips  25 ″,  26 ″ can easily be disengaged by separating the hook and loop portions from each other, moving the strips  25 ″,  26 ″ to the area where the desired new compression level will be applied, and re-engaging the strips to the band  20 ″ at the new location. 
     Advantageously, through use of multiple strips  25 ″,  26 ″, the instruction for use can advise the user or health care personnel to stretch the strips  25 ″,  26 ″ closest to the edge of the band  20 ″ slightly farther than the strips closest to the middle (from a height “h” perspective) in order to allow the band  20 ″ to better constrain the abdominal organs to be compressed (i.e., so that a lower percentage of the organs will be squeezed out of the area enclosed by the band  20 ″). 
     Optionally, the band  20 ″ may also include a pouch or pocket  104  into which a semi-rigid pad  106  may optionally be inserted. The pad  106  will typically be about six inches in height and eight inches in width, and may be contoured to provide for better matching of the contour of the band  20 ″ with the patient&#39;s back and, in some cases, also with the back of the chair that the patient is sitting on or the surface the patient may be lying on. Advantageously, a set of multiple pads, having different thicknesses or contour shapes, may be provided so that the most comfortable pad  106  may be selected for insertion into the pouch or pocket  104 . In general, consistent with matching the contour of the human lower back, in cross section, the pad  106  will be thicker near the center and thinner towards its edges. This is shown in  FIG. 10  in simplified fashion in the end-on cross section of the pad  106  taken along line A-A. Alternatively or additionally, the pad  106  can be contoured in a direction perpendicular to line A-A. This is shown in an example cross section taken at B-B, bearing in mind that any particular pad  106  can be uncontoured, contoured only in the direction shown in the A-A cross section, contoured only in the direction shown in the B-B cross section, or contoured in some fashion in both cross-sectional directions. Note further that the contours shown are each fairly simple for ease of illustration, however, more sophisticated or physiologically accurate back-conforming contours may be used. Note also that, because the pad  106  will add thickness in the center area, at the same stretching of the elastic strips, the waist section around the thicker part of the pad will experience a higher compression pressure. Advantageously, this can provide benefits for patients with orthostatic hypotension (i.e., the development of low blood pressure when standing up from a supine or sitting position) or persons desiring better back support. 
       FIG. 11  illustrates, in simplified form, another alternative non-inflatable variant band  20 ″″ which, as shown, includes two strips of  23   a ,  23   b  of fasteners as in  FIGS. 3 and 3A , an area  24  containing complementary fasteners for mating with the fasteners of strips  23   a ,  23   b , a set of strips  25 ′″ similar to the strips  25 ″ described above that can be used to apply compression pressure of different levels by affixing the fasteners  25 ″ a  on their free ends to the complementary mating fasteners within the vicinity of the neutral marking  92 , the LowComp marking  94 , the MidComp marking  96  or the HiComp marking  98 , as described above, each of which is indicated using a different color or texture. However, as will be seen with this example implementation, the individual strips  25 ′″ are affixed at the end opposite the free end and only extend in one direction. With this example implementation, the band  20 ″″ compression is applied by wrapping the strips  25 ′ in only one direction. In all other respects, the example implementation of  FIG. 11  is the same as described with respect to the example implementation of  FIGS. 10 and 10A . 
     Alternative Protocols 
     Depending upon the particular circumstances, in some cases, it may be desirable to use a different protocol to treat a hypotensive patient or vascular complications. This is because, although blood pressure can be an indicator of vascular issues, in many instances blood pressure is not a good indicator on whether there is too much blood volume shifted to the peripheries or the blood volume is too low for proper cardiac filling producing low cardiac output and low blood pressure. Thus, with this protocol one or more additional indicators, changes in blood density and bioimpedance, can be used as additional or independent means to set the right compression level. 
     In accordance with the above-described protocols, the protocols specify that compression pressure is to increase somewhat linearly or stepwise as the treatment progresses while the vest  10  (with band  20 ,  20 ′ or  20 ″) is being used. The following is an alternative set of protocols that also can be used in conjunction with the vest  10  embodiments described herein to avoid intradialytic hypotension, shock or other vascular complications. 
     These alternative protocols involve monitoring the bioimpedance of the abdominal organs and/or the density of blood. 
     For the bioimpedance measurement, four electrodes will be placed horizontally on the patient around the central front portion of the patient&#39;s waist. An electric current is then imposed to the two outermost electrodes and the voltage of the two inner electrodes is measured. The bioimpedance is then ascertained in a similar manner to that conventionally used for the bioimpedance measurement of the trunk, or similar to that used for bioimpedance measurements made involving the arm or the calf, such as described in Zhu et al., Extracellular fluid redistribution during hemodialysis: bioimpedance measurement and model,  Physiol Measure,  29:S491-S501 (2008). Depending upon the particular bioimpedance measurement technique employed, a single frequency and/or multiple frequencies can be used to assess the impedance of the organs in the waist and to quantify the extracellular fluid volume of the tissue and vasculature and the intracellular fluid of the tissue and vasculature. 
     In addition, or alternatively, blood density will be measured using a conventional blood density or hematocrit monitor or using any other suitable method of determining fluid density, for example, using the monitor described in U.S. Pat. No. 7,220,229, the entirety of which is incorporated herein by reference. For the monitor of U.S. Pat. No. 7,220,229, the venous line of the hemodialysis circuit or a by-pass connecting the radial artery to the radial vein of the patient will be inserted into the slot in the probe of the density monitor so that it can measure the blood density as it would the density of another fluid. 
     In order to set up for these protocol approaches, in the case of hemodialysis, the patient will have the vest  10  on before the patient is connected to the blood lines for the hemodialysis treatment. 
     Thereafter, continuous or substantially continuous measurement of bioimpedance and/or blood density begins. Depending upon the particular implementation, bioimpedance alone, blood density alone or a combination of the two may be used. In his regard, for simplicity, the protocols will be described in a manner that allows for either one alone or both and with the various different implementations of vest  10 . It should be understood and appreciated however that the capability for both measurements is not required, nor is limitation to a particular one of the vest  10  embodiments described herein. If a measurement capability or a particular aspect of a vest or band is not present in the particular implementation, reference to it should simply be ignored. Thus, reference to X “or” Y relating to a claim herein should be read as only X if there is no Y capability, only Y if there is no X capability, and should include both X and Y only if both X and Y capabilities are present. 
     With the foregoing in mind, during the course of treatment, compression will be activated with the vest  10  as specified in the protocols below. 
     If one or more of the following criteria exist:
         a) the average blood pressure drops below about 110 mm Hg, and/or   b) the impedance (or primarily the resistance) shows a decrease of less than about 5% of its initial value, and/or   c) the blood density shows an increase by about 1 g/l,
 
then the compression pressure is increased to about 5 mm Hg by, for example, bladder inflation or stretching and affixing the elastic strips of the band at about a lower part of the LowComp marking.
       

     When treatment is completed, then this compression pressure will be released. 
     If there is a further measured drop in blood pressure, decrease in impedance or the increase in blood density, then further action may be taken based upon, for example, the following additional or alternative protocol. 
     If the average blood pressure drops below about 100 mm Hg, then the compression pressure may be increased to about 10 mm Hg by, for example, bladder inflation or stretching and affixing the elastic strips of the band to a higher part of the LowComp marking This is referred to as “Course A.” Once treatment is complete, then the compression pressure is released. 
     If, however, before Course A is complete, the impedance shows no decrease from its initial value and/or the blood density shows an increase by about 2 g/l, then the compression pressure may be increased to about 20 mm Hg by, for example, bladder inflation or stretching and affixing the elastic strips of the band at about the MidComp marking. This is referred to as “Course B.” If there is no further change, once treatment is complete, then the compression pressure is released. 
     However, if, before the completion of Course B, the impedance shows about a 10% increase from its initial value and/or the blood density shows an increase by about 3 g/l, then the compression pressure may be increased to about 25 mm Hg by, for example, bladder inflation or stretching and affixing the elastic strips of the band to the HiComp marking. Again, if there is no further change, once treatment is complete then the compression pressure is released. 
     The values specified above for density change and bioimpedance change are only exemplary. It is expected that, in some cases, a physician or other health care professional will further analyze the bioimpedance and density results of a given patient and the patient&#39;s quality of life to individualize the values and pressures in the above protocols and they may use different reading values as triggers, higher levels of compression pressure and/or longer treatment time to care for that patient. 
     Having described and illustrated the principles of this application by reference to one or more preferred embodiments, it should be apparent that the preferred embodiment(s) may be modified in arrangement and detail without departing from the principles disclosed herein and that it is intended that the application be construed as including all such modifications and variations insofar as they come within the spirit and scope of the subject matter disclosed herein.