Patent Publication Number: US-8114037-B2

Title: Hydraulically actuated external pulsation treatment apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention related generally to medical treatment devices, and, more particularly, to a counterpulsation treatment apparatus for treating reduced cardiac output in patients, specifically, for treating occlusions in coronary arteries. 
     2. Description of the Related Art 
     External counterpulsation has developed as a means of treating reduced cardiac output and circulatory disorder stemming from disease. Counterpulsation treatment involves the application of pressure, usually from distal to proximal portions of a patient&#39;s extremities, where such application is synchronized with heart rhythms. The treatment augments blood pressure, typically increasing pressure during the diastolic phase of the heart, as such treatment is known to relieve and treat medical conditions associated with reduced cardiac output. Clarence Dennis described an early hydraulic external counterpulsation device and method of its use in U.S. Pat. No. 3,303,841 (Feb. 14, 1967). Dr. Cohen, in American Cardiovascular Journal (30(10) 656-661, 1973) described another device for counterpulsation that made use of balloons which would sequentially inflate and deflate around the limbs of a patient to augment blood pressure. Similar devices using balloons have been described in Chinese patents CN 85200905 (U.S. Pat. No. 4,753,226); Chinese patents CN 88203328, and CN 1057189A. 
     A series of Zheng patents, including U.S. Pat. No. 4,753,226 (Jun. 28, 1988), U.S. Pat. No. 5,554,103 (Sep. 10, 1996), and U.S. Pat. No. 5,997,540 (Dec. 7, 1999) disclose counterpulsation devices employing sequential inflation of balloon cuffs around the extremities, wherein the cuffs are inflated by a fluid. All three Zheng patents disclose an external counterpulsation device where a series of air bladders are positioned within a rigid or semi-rigid cuff around the legs. The bladders are sequentially inflated and deflated with fluid, such that blood pressure is augmented in the patient. The Zheng &#39;103 and Zheng &#39;540 patents provide for cooled fluid and for monitoring of blood pressure and blood oxygen saturation; however, both retain a similar mechanism dependent on compression of fluid such as air. The Zheng &#39;540 patent modifies the shape of the air bladder and cuffs, but retains a similar mechanism requiring rapid fluid distribution, influx and efflux through balloons in the cuffs. 
     U.S. Pat. No. 3,734,087 to Sauer et al., U.S. Pat. No. 3,786,802 to Hagopian, et al. and U.S. Pat. No. 3,835,845 to Maher, all disclose a system that utilizes a hydraulically actuated rod to move a platen from a resting position to a position placing pressure on a liquid filled bladder. Liquid is either removed or added to the bladder over several cycles in order to regulate the pressure against the patient&#39;s legs. This procedure of regulating the pressure output of the invention is inefficient due to the time and imprecision involved in making the necessary adjustments. 
     Bladders are also utilized to regulate the pressure exerted on the subject&#39;s extremities in U.S. Pat. No. 3,866,604 to Curless, et al. and U.S. Pat. No. 3,654,919 to Birtwell. As stated above, this procedure is ineffective and imprecise. Britwell further teaches the use of a hydraulically driven piston to switch between a suction zone and a hydraulic zone. In a first position, liquid is released into the bladder system affixed circumferentially around the subject&#39;s legs. In an opposite second position, the liquid is removed. This invention does not allow for quick and precise adjustments of the resulting pressure and the piston is not adjustable to a plurality of positions in order to more finely tune the pressure output. 
     There are several deficiencies with prior pulsation treatment devices. First, the required circuitous movement of fluid through the apparatus causes a delayed response to changes in pressure settings for the balloons or air bladders. Second, there is also a consequent inability to manipulate action of the cuffs with a high degree of precision. Third, many of the prior art devices require a relatively heavy and noisy compressor. Fourth, the prior devices lack portability due to their large size and weight, and their reliance on a compressor. There are also deficiencies in some of these devices with regard to patients being bounced up and down while undergoing pulsation treatment. 
     Electromechanical solenoids were typically used to actuate the prior art designs in part due to their relative ease of installment as opposed to pneumatic or hydraulic actuators. Typically solenoids are also utilized for their quick operation. U.S. patent application Ser. No. 11/420,133 to Michael Lewis, the inventor herein, utilizes an electromechanical actuator comprising a solenoid that will operate on a 120-volt source of electric power. While this particular type of actuator is effective, a hydraulic actuator will prove to be more powerful and less prone to the typical wear seen in electrical components. 
     Hydraulic actuators are ideal for applications requiring precise control and smooth motion. Utilizing hydraulic actuators will allow for a greater plurality of adjustments in the tension of the cuff system due to the ease of regulating the pressure exerted on the hydraulic actuator itself. These types of minute adjustments are not as easily obtainable when utilizing an electromechanical actuator. The solenoids typically used in electromechanical actuators are better equipped to fluctuate from a fully open position to a fully closed position. While it may be possible to generally operate between these two extremes, the resultant operation will not be as fine tuned as when a hydraulic actuator is utilized. 
     Hydraulic actuators require less treatment table space because the actuators themselves are relatively smaller and less bulky than their electromechanical counterparts allowing for a relatively smaller frame. Hydraulic actuators produce less heat as well preventing premature shut downs due to overheating, which allows for extended use. Further, the hydraulic system&#39;s accumulator stores energy while the actuator is stationary which is a great advantage when the actuators are used intermittently, as in the present invention. A further benefit is the ability for several hydraulic actuators to share a single pump. This ability to operate several actuator from a single pump unit can result in lower costs per treatment as compared to electromechanical systems. Finally, the pressure generated from a hydraulic system can be maintained at a constant level without the need for signification additional energy. 
     A need therefore exists for a pulsation treatment apparatus that provides a rapid response to changes in applied pressure settings, and that permits control of cuff pressure with an even higher degree of precision than with an electromechanical actuator. Preferably, such a treatment apparatus will not require fluid filled balloons or air bladders and will not subject the patient to undesirable or unnecessary movement. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention addresses the aforementioned needs. According to one embodiment of the invention, an apparatus for use in counterpulsation treatment of a patient, wherein pressure is applied to the patient&#39;s blood vessels to stimulate blood flow, comprises a cuff to be received on a patient&#39;s extremity. The cuff has first and second ends. First and second hydraulic actuators are associated with the cuff and controllably operable to a plurality of positions within a range of positions. The range of positions ranges from an original position to a maximum constricted position. The actuators are disposed on opposite sides of the patient. The cuff applies maximum pressure to the patient&#39;s blood vessels to constrict the blood vessels in the maximum constricted position of the plurality of positions of the actuator. The cuff applies no pressure to the patient&#39;s blood vessels in the original position of the plurality of positions of the actuator. The actuator is controllably operable from the relaxed position to any of the positions within the range of positions on activation. 
     This invention is a hydraulically actuated pulsation apparatus for use in external pulsation, including counterpulsation or simultaneous pulsation, treatment of reduced cardiac output, congestive heart failure, angina pectoris, heart disease and other circulatory disorders. Counterpulsation has traditionally involved the application of sequential pressures on the lower legs, upper legs and hip areas through pneumatic cuffs placed on those regions. Application of pressure to the extremities has been timed to correlate with a patient&#39;s physiological rhythms, such as diastolic and systolic phases of the heart. This application of force by the cuff causes a retrograde wave back up the arteries toward the heart, whereby blood pressure is increased during the diastolic phase of the heart. The sequence of compressions could be reversed to force blood toward the feet. This enhanced diastolic pressure is recognized as beneficial for treatment of medical conditions relating to blood circulation. The present invention utilizes a hydraulically controlled flexible cuff that on activation compresses and applies pressure to a patient&#39;s body. Rather than pneumatic or inflatable devices, the present invention uses the cuff to constrict a portion of the patient&#39;s body, typically the abdomen and/or the upper and/or lower legs. The cuff is designed to partially encircle an extremity such as a leg, arm, or midsection of a patient&#39;s body. Hydraulic means for operation of the cuff is preferably one or more linear hydraulic cylinders mounted on a frame and connected to the cuff through a suitable linkage. Positive pressure from the cuff forces blood from the extremity toward the patient&#39;s heart during diastole. It is this augmentation of blood pressure during diastole that provides curative benefit from counterpulsation treatment. Typically, the cuff will release immediately prior to the systolic phase of the patient&#39;s heart. 
     Because the clinician may adjust the sequence in which the actuators are activated, blood can be forced away from the heart to a foot or hand. This is beneficial when treating a diabetic patient with poor blood circulation to these extremities. 
     It is therefore an object of the present invention to provide a pulsation, including counterpulsation or simultaneous pulsation, treatment apparatus that operates by hydraulic rather than by pneumatic or electromechanical actuation means, and which can be precisely controlled by the operator or automated treatment program. It is a further object of the invention that the treatment apparatus transmit data regarding local pressure applied to the patient. It is a further object of the invention that the pressure applied to the patient by the apparatus be completely adjustable, such that the apparatus may apply fixed pressure, less than its maximum pressure, at times during operation. Other objects of the invention are apparent from the specification and claims as set forth below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following Detailed Description of Example Embodiments of the Invention, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a top and front perspective view of a pulsation actuator unit of the present invention for use on a patient&#39;s leg with the actuators shown in their retracted positions. 
         FIG. 2  is a side elevation view of the actuator unit of  FIG. 1 , as applied to a patient&#39;s leg. 
         FIG. 3  is a top and rear perspective view of the actuator unit of  FIG. 1 . 
         FIG. 4  is a side elevation view of the entire treatment apparatus of the invention, as applied to a patient&#39;s hip area. 
         FIG. 5  is a perspective view of a cuff for the actuator unit of  FIG. 1 . 
         FIG. 6  is a cross-sectional view of the cuff of  FIG. 5 , taken at section  6 - 6  in  FIG. 5 . 
         FIG. 7  is a cross-sectional view of the cuff of  FIG. 5 , taken at section  7 - 7  in  FIG. 5 . 
         FIG. 8  is the display of a computer monitor screen of the pulsation treatment system of this invention. 
         FIG. 9  is a front and top perspective view of the power unit of the present invention. 
         FIG. 10  is a side perspective view of the power unit of  FIG. 9 . 
         FIG. 11  is a fluid flow schematic for the treatment apparatus of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION 
     The invention and its advantages are best understood by referring to the drawings, like numerals being used for like and corresponding parts of the various drawings. In  FIG. 1 , there is shown in perspective view an actuator unit, generally designated  10 , used in the treatment apparatus of the invention. Actuator unit  10  can be used for pulsation and counterpulsation treatment of a patient&#39;s extremities and hip area. Actuator unit  10  includes a frame  12 , a pair of actuators  14 , a plate  36 , among other components described hereinbelow. 
       FIG. 2  illustrates the use of actuator unit  10  for treating a patient&#39;s upper or lower leg  26  or other body member. In the illustrated embodiment, actuator  14  is hydraulic, and includes hydraulic cylinder  18 , shaft  20 , extensions  23 , and roller  24 . Hydraulic cylinder  18  is mounted within frame  12 . Hydraulic actuators  14  are pivotally connected at their lower end to frame  12  by connector  119 . Shaft  20  contains upper and lower ends. Shaft  20  is connected to and driven axially and linearly by hydraulic cylinder  18 . Roller  24  is rotatably connected to the upper end of hydraulic cylinder  18  through a linkage  23 ,  25  made up of pin  25  connected to the upper end of shaft  20  and lower end of extension  23 . Roller  24  is rotatably connected between the upper ends of extensions  23 . The first end  28  of cuff  16  is fixed to roller  24 . 
     Actuator  14  is hydraulically driven, and is controllably operable to a plurality of positions within a predetermined range of positions. Actuator  14  positions range from an original position to a maximum constricted position. Shaft  20  is linearly driven to a plurality of positions within a range of positions, the range of positions of shaft  20  corresponds to the range of positions of actuator  14 . The original position of actuator  14  corresponds to original position  32  of roller  24 , and maximum constricted position of actuator  14  corresponds to maximum constricted position  34  of roller  24 . 
     Cuff  16  is sized to partially encircle the patient&#39;s leg  26  peripherally. First end  28  of cuff  16  is removably attached to roller  24  on shaft  20 . Second end  30  of cuff  16  is removably attached to curved plate  36  of actuator unit  10  by a hook and loop fastener system  38 ,  40 . The hook and loop fastener system has a first fastener component  38  attached to the second end  30  of cuff  16 ; and a second fastener component  40  attached to plate  36 , as best seen in  FIG. 2 . Plate  36  is curved to conform generally to the patient&#39;s leg. In the embodiment illustrated in  FIGS. 2-4 , plate  36  is generally quarter-cylinder shaped. 
     In the maximum constricted position of the plurality of positions of actuator  14 , cuff  16  applies a predetermined maximum pressure to the patient&#39;s leg and blood vessels therein to constrict the blood vessels. In the original position of the plurality of positions of actuator  14 , cuff  16  applies zero pressure to the patient&#39;s blood vessels so as to not constrict them at all. Actuator  14  is controllably operable from the original position to any of the positions within the range of its positions on hydraulic activation. 
     In the embodiment of the invention herein illustrated, cuff  16  is rectangular in shape when flat, similar to a wide strap. In alternative embodiments of the invention (not illustrated), cuff  16  is slightly trapezoidal or conical in shape when flat so as to better accommodate increasing or decreasing thicknesses of the patient&#39;s leg or other extremity. Cuff  16  is essentially like cuff  58  illustrated in  FIGS. 5-7  and described below, except that cuff  16  does not include a thickened portion  56  at its center. A pressure relief valve (not illustrated) is attached to the bladder in cuff  16 . 
     Referring to  FIG. 2 , pressure sensor  42  is embedded in or attached to the surface of cuff  16 . In one embodiment of the invention, pressure sensor  42  provides data to an external control unit (not illustrated) for manual or automatic adjustment of the pressure applied to the patient by cuff  16 . Pressure sensor  42  detects the air pressure in cuff  16  which correlates to the degree of compression accomplished by cuff  16 , and by the respective actuator  14  during operation. Pressure sensor  42  provides electronic feedback data to the operator or the computer. This data is then processed during treatment for possible adjustment of actuator  14  and cuff  16  operation. 
     In their original positions  32 , rollers  24  of actuators  14  are extended toward the patient&#39;s leg  26 . In this position, cuff  16  applies no pressure on the patient&#39;s blood vessels. In their maximum constricted positions  34 , rollers  24  are retracted back toward hydraulic cylinders  18  and away from the patient&#39;s leg  26 .  FIG. 3  is a top and rear elevation view of actuator unit  10 . 
     Referring next to  FIG. 4 , there is shown a side elevation view of the actuator unit of  FIG. 1  as applied to a patient&#39;s hip area, according to a second example embodiment of the invention. In this embodiment, the axes of actuators  14  and shafts  20  are pivoted at connector  119  approximately 45 degrees from horizontal to accommodate the larger hip area. However, in alternative embodiments, actuators  14  are tilted at other angles as best suited to the specific application of the invention. 
       FIG. 4  illustrates the use of treatment apparatus  11  of the present invention for providing a patient&#39;s hip area with pulsation treatment, according to an example embodiment of the invention. In the illustrated embodiment, the patient  52  lies on his back on a treatment table  54 . Treatment apparatus  50  includes at least two actuator units  10  disposed on opposite sides of the patient near the patient&#39;s hips. The actuator units  10  face the patient  52  and each other. Cuff  58  includes a thickened portion  56  that is placed over the patient&#39;s lower abdomen. 
     The opposite ends  60  and  62  of cuff  58  correspond to the first and second ends of cuff  58 . The linkages are made up of pins  25  connected to the upper ends of shaft  20 , and extensions  23  rotatably connected at their lower ends to pins  25 . Rollers  24  are rotatably connected between the upper ends of extensions  23 . The ends  60  and  62  of cuff  58  pass around rollers  24  of actuator units  10  and are fastened to cuff  58  by hook and loop fasteners attached to cuff  58 , or by other suitable fasteners. Cuff  58  thus applies pressure to the patient through thickened portion  56 . 
     Actuator frames  12  are slidably mounted on treatment table  54  for sliding movement toward and away from the patient  52 . The lower portions of actuator frames  12  slide laterally within channel guides  64 . Guides  64  also restrain treatment actuator units  10  from vertical movement with respect to table  54  when cuff  58  is tensioned by actuators  14 . In an alternative embodiment (not illustrated), only one of actuator frames  12  is slidably mounted, the other actuator frame being fixed in place on treatment table  54 . In other alternative embodiments (not illustrated), actuators  14  are restrained from vertical movement by being affixed in other ways to treatment table  54 , or by being affixed to one another by a rigid or flexible connecting member (not illustrated) passing under the patient. 
     Referring next to  FIG. 5 , cuff  58  is made up of two side portions  66  connected by thickened portion  56  at the center of cuff  58 . A pair of straps  68  are attached to each outer end  70  of side portions  66  of cuff  58 . Hook and loop fasteners  72  are attached near the outer ends of straps  68  for attaching straps  68  to rollers  24  of actuators  14 . 
     Referring to  FIG. 6 , side portions  66  of cuff  58  are made up of two inflatable rubber bladders  74 . Bladders  74  extend the lengths of side portions  66  and are enclosed by a fabric cover  76 . In one embodiment of the invention, fabric cover  76  comprises nylon, as sold by Dupont Corporation under the tradename Cordura. Cover  76  is stitched along its center seam  78 . As seen in  FIGS. 5 and 6 , each bladder  74  is inflated with air and deflated through a flexible air hose  80 . Air hoses  80  supply air to bladders  74  from a hand pump (not illustrated). 
     Referring to  FIG. 7 , thickened portion  56  of cuff  58  is also made up of inflatable rubber bladders  74  enclosed by fabric cover  76 . However, bladders  74  are much thicker in thickened portion  56  than they are in side portions  66 , thereby providing a cushioning effect to the patient when inflated with air. The portions of bladders  74  within thickened portion  56  are in fluid communication with the portions of bladders  74  in side portions  66  of cuff  58 . Therefore, inflation of side portions  66  through air hoses  80  also inflates thickened portion  56 . Air pressure sensors  42  are installed on the interior of bladders  74  in thickened portion  56 . Pressure signal wires  82  lead from pressure sensors  42  to the signal processor (not shown) for actuator unit  10 . Pressure relief valves  84  are also installed on the interior of bladders  74  in thickened portion  56 . Pressure relief valves  84  prevent damaging overcompression of the patient by cuff  58 . 
     Cuff  16  for leg pulsation treatment is like cuff  58  described above, except that cuff  16  does not have a thickened center portion  56 . The inflatable bladders of cuff  16  are therefore uniform in thickness over their entire lengths. 
     Referring to  FIGS. 9-11 , the power unit, generally designated  120 , controls the hydraulic actuators  14  within actuator unit  10 . In the depicted exemplary embodiment, power unit  120  provides the hydraulic fluid for two actuator units  10 . Motor  116  provides the necessary power to operate the hydraulic system. Motor  116  is functionally attached to power unit  120 . Reservoir  110  contains a submersible hydraulic pump (not illustrated) that is attached to the interior of reservoir  110 . Reservoir  110  is replenished with hydraulic fluid through reservoir access port  125 . In an exemplary embodiment, access port  112  contains a threaded protrusion (not illustrated) extending outwardly from reservoir  110 . This protrusion is threadedly attached to cap  112  in order to close reservoir access port  125 . 
     Directional valves  117  are connected to power unit  120  at connection junction  121 . Pressure relief valve  118  is connected intermediate at least one directional valve  117  and connection junction  121 . Relief Valve  118  relieves the pressure in the system once the pressure has surpassed a predetermined limit and will reclose once normal operating pressure has been achieved. 
     The submersible hydraulic pump supplies hydraulic fluid via supply line  114 . Supply line  114  is removably connected to first side  122  of connection junction  121 . Return line  113  is removably connected to second side  123  of connection junction  121 . Return line  113  returns the hydraulic fluid to reservoir  110  by first directing the fluid through filter  115  in order to remove impurities and keep the fluid in reservoir  110  uncontaminated. 
     In an exemplary embodiment, connection junction  121  is comprised of eight connection terminals  126 . Connection terminals  126  removably connect to their respective supply hoses  100  or return hoses  101 , depicted in  FIGS. 2 ,  3 , and  11 . In an exemplary embodiment, supply hoses  100  and return hoses  101  are flexible and all remaining lines are rigid. In a second exemplary embodiment, supply hoses  100 , return hoses  101 , supply line  114  and return line  113  are all flexible. 
     As shown in  FIG. 2 , supply hose  100  is removably connected to actuator  14  at connection terminal  102 . Return hose  101  is removably connected to actuator  14  at connection terminal  103 . 
     Referring to the fluid flow schematic in  FIG. 11 , submersible hydraulic pump  111  pumps hydraulic fluid to directional or 4-way control valves  117 , which control the flow of the hydraulic fluid. Pressurized hydraulic fluid is transmitted to actuators  14  through connection junction  121  and supply hoses  100 . The hydraulic fluid is returned from actuators  14  through return hoses  101  and connection junction  121 . Return line  113  then directs the hydraulic fluid to filter  115  and the filtered fluid is returned to reservoir  110 . 
     In one embodiment, directional valves  117  are solenoid operated directional valves, as manufactured by Northman Fluid Power Inc., as part number SWH-G02-C3-D24. Pressure relief valve  118  is a modular relief valve, as manufactured by Northman Fluid Power, Inc., as part number MRF-02-P-2. Motor  116  is a one and a half horsepowered electric motor, as manufactured by WEG Electric Motors Corporation, as part number 00158ES1BF56CFL. 
     The invention includes a method of treating a patient&#39;s medical condition using pulsation or counter pulsation wherein pressure is applied to and released from a patient&#39;s blood vessels to stimulate blood flow correlated with the patient&#39;s physiological data based on data received from at least one physiological measuring device. This method includes (1) applying a cuff to a patient. The cuff has at least one hydraulic actuator connected to it. The actuator is controllably operable to a plurality of positions within a range of positions. The actuator positions range from an original position to a maximum constricted position. The cuff applies maximum positive pressure to the patient&#39;s blood vessels to constrict the blood vessels in the maximum constricted position of the plurality of positions of the actuator. The cuff applies no pressure to the patient&#39;s blood vessels in the original position of the plurality of positions of the actuator. The hydraulic actuator unit is controllably operable from the original position to any of the positions within the range of positions on activation. The hydraulic actuator unit is operable at variable frequencies. At least one such variable frequency is responsive to at least one type of data from a physiological measuring device. In one embodiment of this method, the cuff has a pressure sensor for communicating with an external processor. 
     The method includes the further steps of (2) applying sensors to the patient to detect physiological data; (3) detecting physiological data from the patient through use of the sensors; (4) transmitting the physiological data electronically from the sensors to a processor; (5) electronically processing the physiological data to determine when the patient&#39;s heart is in a diastolic or a systolic phase; (6) electronically timing the activation of each hydraulic cylinder  18  to correlate with the phases of the patient&#39;s heart; and (7) modifying the timing of the activation of the plurality of hydraulic cylinders according to changes in the physiological data affected by the activation. 
     In an exemplary application of the device and method, a patient who is to be given pulsation treatment lies down on his back on treatment table  54 . He places his legs against curved plates  36  of actuator units  10 . Cuffs  16  of actuator units  10  are placed around his upper and lower legs, as seen in  FIG. 2 . Actuator units  10  are moved together to treat the hip area so that their plates  36  are brought into contact with the patient&#39;s hips, as seen in  FIG. 4 . Cuff  58  is then placed over the patient&#39;s lower abdomen, and ends  60  and  62  of cuff  58  are secured to rollers  24  of actuator units  10  so that the slack is removed from cuff  58 . Hand pumps are then operated to inflate bladders  74  in all the cuffs. Inflation of bladders  74  applies a gentle pressure to the patient&#39;s legs and lower abdomen. 
     In operation of actuator units  10 , when actuators  14  are hydraulically engaged, actuator shafts  20  retract back toward the actuators  14 , thereby tensioning cuffs  16  or  58 , thus applying pressure to the patient according to predetermined medical treatment parameters. The pressure applied to the patient varies in direct proportion with the force produced by actuators  14 , which in turn varies with the hydraulic pressure supplied to actuators  14 . The pressure applied to the patient by cuffs  16  or  58  is reduced by disengaging the hydraulic pressure used to pull the shafts  20  toward actuators  14  which allows the patients body to exert the necessary resistance to extend shafts  20  away from actuator  14 , relaxing cuffs  16  or  58 . In an alternative embodiment, hydraulic pressure is exerted in order to extend shafts  20  to original position  32 . 
     The treatment parameters are correlated with the patient&#39;s physiological data, such as diastolic and systolic phases of the heart, to augment blood pressure as necessary. The pressure strength, pressure and relaxation duration, and delay between compressions can be varied separately for each cuff and individual actuator used in a treatment session. The actuators can apply pressure to the patient in many combinations of sequence, amounts of pressure, and duration. The preferable manner is where graded pressure is applied sequentially. Each actuator and respective cuff may also release pressure at variable sequences and by varying degrees. The actuators can relax the cuffs in various manners. In an exemplary application, the cuffs may be relaxed all at once. 
     Graded pressure means that each actuator is set to apply a specific, but not necessarily identical, amount of pressure to the patient. For example, the actuators for a patient&#39;s calves may be set to apply pressure at a greater strength than the actuators for the patient&#39;s thighs. Actuators are preferably adjusted so that pressure will increase or decrease from distal to proximal direction on a patient. Pressure on a patient can be applied by one actuator at a time, in any sequence, and at any pressure within the treatment parameters. 
     An individual actuator may be removed from a sequence of activations, or can be set independently so that one cuff applies pressure more frequently per period of time than will another cuff. Each individual actuator will preferably operate in sequence, whether or not there are gradations in pressure from actuator to actuator. 
     Graded sequential pressure involves variations in constriction force or pressure from actuator to actuator, and where actuators operate in sequence. For example, actuators for a patient&#39;s calves may be set to apply greater pressure than actuators for the patient&#39;s hips. In addition to graded pressure, the actuators are generally set to activate in sequence starting from the patient&#39;s calves and moving upward to the patient&#39;s hip. 
     The cuffs apply pressure preferably in sequence on a patient from a distal to proximal direction generally with increments in the range of 35.0 to 50.0 milliseconds between initial activation of separate sequential cuffs. All cuffs preferably operate within a compression strength range of zero to 7.0 pounds of pressure per square inch. 
     In various embodiments of the invention, the length and diameter of curved plate  36  differs to accommodate different body shapes and sizes. For instance, curved plate  36  may be sized to accept a calf, thigh, forearm, or upper arm of an infant, child, or adult patient. 
     While more than one cuff can be operated simultaneously, each of the cuff actuators can be operated separately with different or identical compression sequences, strengths, and delays. For instance, with the present invention, it would be possible to cause a particular cuff to constrict more frequently in a set period of time than the other cuffs. Additionally, the present invention can advantageously apply pressure to an extremity almost instantaneously from the time the activation signal is sent due to its hydraulic rather than pneumatic operation. The applied pressure can also be varied with a high degree of precision with the present invention. Instead of simultaneous deflation of all cuffs at systole, the present invention, which does not require deflation, can vary the degrees of pressure on each cuff during systole. Because the apparatus of this invention does not rely on inflation or deflation of the cuffs, it can more gradually reduce the pressure applied by each individual cuff. 
     In an example embodiment of the invention, cuff  16  of actuator unit  10  is 6 inches wide, 24 inches long and 1 inch thick. Preferably, the width of cuff  16  is within the range of 1 to 20 inches. In one embodiment, cuff  58  of treatment apparatus  10  is 6 inches wide, 24 inches long, and 3 inches thick. Preferably, the width of cuff  58  is within the range of 3 to 15 inches. 
     In one embodiment, curved plate  36  of actuator unit  10  is 10 inches in diameter, 10 inches long, and ¼ inch thick. In one embodiment, curved plate  36  of actuator unit  10  for use on the hips is 12 inches in diameter, 10 inches long, and ¼ inch thick. 
     In one embodiment, hydraulic cylinder  18  is manufactured by SMC Corporation of America, as part number CHDKDB25-50-F9BV. Pressure sensor  42  is an air pressure sensor, as manufactured by Freescale Co., as part number MPX4250A. 
     Compression of the cuffs may be correlated with physiological data including, but not limited to EKG, plethysmograph, cardiac output, heart rate, blood pressure, heart stroke volume, blood oxygen levels, systole and diastole. A variety of devices in the medical industry are used to detect and electrically transmit this physiological data from a patient. After such data is collected, it is typically processed within pulsation parameters to determine the proper sequence of cuff activation. Such data is typically received and processed by computer with cardiac pulsation treatment software. Typically, a computer processes the patient&#39;s electronic physiological data as well as electronic feedback data obtained from pressure sensors  42  installed in the cuffs. Treatment parameters can be changed based on either input from the clinician or from the processor program. 
     In one embodiment of the invention, the computer or processor interfaces with an interactive touch screen video monitor, as illustrated in  FIG. 8 . During a counterpulsation treatment session, the monitor displays the patient&#39;s physiological indicators, such as systole, diastole, blood pressure, oxygen saturation of the blood, ECG, stroke volume, diastolic to systolic ratios, cardiac output, and heart rate. Through the monitor, the attending physician, nurse or technician monitors and controls the compression pressure, sequence, frequency of activation, and timing delay for each of the actuators, and may deactivate any of the actuators from the treatment program. The monitor also tracks activation status for each of the cuffs, showing for each cuff, data including but not limited to compressions, sequence with other cuffs, and strength of each compression. The attending physician, nurse or technician is thus able to maintain optimal benefit of the counterpulsation treatment. This is important as it is known that any patient&#39;s responsiveness or tolerance to treatment can change in a relatively short period of time during treatment. The user may also obtain printouts of monitored data through the interactive monitor. 
     The pulsation and counterpulsation apparatuses of the present invention, and many of their intended advantages, will be understood from the foregoing description of example embodiments, and it will be apparent that, although the invention and its advantages have been described in detail, various changes, substitutions, and alterations may be made in the manner, procedure, and details thereof without departing from the spirit and scope of the invention, as defined by the appended claims, or sacrificing any of its material advantages, the forms hereinbefore described being merely exemplary embodiments thereof.