Garment Detection Method and System for Delivering Compression Treatment

CROSS-REFERENCE TO RELATED APPLICATIONS

0001This application is a continuation of U.S. patent application Ser. No. 11/143,548, filed Jun. 2, 2005, which is a continuation-in-part of U.S. patent application Ser. No. 10/784,323, filed Feb. 23, 2004, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

0002The present disclosure generally relates to the field of vascular therapy for application to a limb of a body, and more particularly, to a compression treatment system having a controller that regulates fluid flow and a method of use thereof.

0003A major concern for immobile patients and persons alike are medical conditions that form clots in the blood, such as, deep vein thrombosis (DVT) and peripheral edema. Such patients and persons include those undergoing surgery, anesthesia, extended periods of bed rest, etc. These blood clotting conditions generally occur in the deep veins of the lower extremities and/or pelvis. These veins, such as the iliac, femoral, popliteal, and tibial return deoxygenated blood to the heart. For example, when blood circulation in these veins is retarded due to illness, injury or inactivity, there is a tendency for blood to accumulate or pool. A static pool of blood is ideal for clot formations. A major risk associated with this condition is interference with cardiovascular circulation. Most seriously, a fragment of the blood clot can break loose and migrate. A pulmonary emboli can form blocking a main pulmonary artery, which may be life threatening.

0004The conditions and resulting risks associated with patient immobility may be controlled or alleviated by applying intermittent pressure to a patient's limb, such as, for example, a leg including the thigh, calf and foot to assist in blood circulation. Known devices have been employed to assist in blood circulation, such as, one piece pads and compression boots. See, for example, U.S. Pat. No. 6,290,662 to Morris et al. entitled “Portable, Self-Contained Apparatus For Deep Vein Thrombosis (DVT) Prophylaxis” and U.S. Pat. No. 6,494,852 to Barak et al. entitled “Portable Ambulant Pneumatic Compression System.”

0005For example, sequential compression devices have been used, which consist of an air pump connected to a disposable wraparound pad or garment by a series of air tubes. The wraparound pad is configured for placement about a portion of a patient's leg, such as the thigh, calf, or foot. Multiple pads may be mounted to the leg to cover the various portions of the leg. Air is then forced into different parts of the wraparound pad(s) in sequence, creating pressure around the thigh, calf, or foot, thereby improving venous return.

0006These known devices may suffer from various drawbacks due to their bulk and cumbersome nature of use. These drawbacks reduce comfort, compliance and may disadvantageously prevent mobility of the patient as recovery progresses after surgery.

0007Further, such known sequential compression devices typically include a controller assembly that regulates air flow and pressure in the wraparound pad(s). The controller assembly can be mounted to a bed and plugged into a wall outlet for power during use. This arrangement, however, can present challenges for example, when the patient needs to perform certain tasks, e.g., bathroom, physical therapy, etc. In these situations, the pads are usually removed, thus disadvantageously discontinuing vascular therapy. Thus, these controller assemblies suffer from various drawbacks because they do not accommodate patient transport or mobility and are not typically adaptable for inflation of thigh, calf, and foot pads.

0008Other sequential compression devices and systems are known in the art. U.S. Pat. No. 6,786,879 to Bolam et al., entitled “Gradient Sequential Compression System for Preventing Deep Vein Thrombosis,” discloses a gradient sequential compression system to prevent deep vein thrombosis. The system has a controller which includes a plurality of feeder valves pneumatically connected to each of the chambers and a microprocessor-based control unit for opening only one of the feeder valves at a time during an inflation cycle, so that each of the chambers can be independently inflated to predetermined pressure levels. The programming of the system controller can either be performed manually by the user through a display interface or by the use of a universal connecting device that senses the mode of operation associated with a sleeve connected thereto and automatically configures the system controller.

0009Another sequential compression device is disclosed in U.S. Pat. No. 5,876,359 to Bock et al., entitled “Sequential Compression Device Controller,” that is currently owned by the assignee of the present application, Tyco Healthcare Group LP. Bock et al. disclose a controller for applying sequential compression to a limb and includes a variable speed motor connected to a pump and an electronic control circuit to drive the pump motor. The system disclosed in Bock et al. includes a pressure transducer in communication with a manifold and adapted for monitoring sleeve pressure.

0010Another known system is disclosed in U.S. Pat. No. 6,171,254 to Skelton. Skelton discloses a blood pressure monitoring system for automatic unattended operation. During the inflation of cuff, an initial inflation period is defined between the start time and a predetermined end time. After the predetermined end time, the pressure in the cuff is measured and compared to the initial cuff pressure. A microprocessor determines the difference between the initial pressure and the final pressure over the inflation period and produces a curve for identifying the attached cuff.

0011U.S. Pat. No. 6,450,966 to Hanna discloses an apparatus and a method for the automatic identification of a given one of a predetermined plurality of cuff assemblies that are connectable to a sphygmomanometer for use in a blood pressure measurement procedure. A cuff assembly has a corresponding gas-flow restrictor which allows pressure measurements during the deflation of a cuff to be correlated for identification. Hanna preferably uses at least two pressure transducers. Similarly, U.S. Pat. No. 5,003,981 to Kankkunen discloses a flow restriction means for identifying a cuff.

0012In U.S. Pat. No. 4,501,280 to Hood Jr., a cuff size is determined based on the propagation time for an audio pulse to propagate to, through, and back from the cuff that is inflated to a predetermined pressure. The measured time is compared to a predetermined threshold value that correlates the measured time to an adult or pediatric cuff thereby identifying the attached cuff. Similarly, U.S. Pat. No. 5,060,654 to Malkamaki relates to automatic identification for a cuff using a trigger pulse from a valve to a pressure sensing element followed by measuring the width of a detected pulse.

0013In U.S. Pat. No. 5,301,676 to Rantala et al., an automatic identification method for the cuff of a sphygmomanometer is disclosed. The cuff is identified by measuring values of pressure in at least two spaced apart locations and determining the difference in the pressure values wherein a difference in pressure identifies a pediatric cuff while no pressure difference signifies an adult cuff.

0014Therefore, it would be desirable to overcome the disadvantages and drawbacks of the prior art with a compression treatment system having a controller that is adaptable for inflating thigh, calf and foot sleeves and accommodates patient transport and mobility to provide continuous vascular therapy. It would be desirable if the system automatically detects the types of garments connected thereto and having any combination or number of bladders therein. It would be highly desirable if the system included a pneumatic circuit that facilitates pressure monitoring with a single pressure transducer to achieve the advantages of the present disclosure. It is contemplated that the compression treatment system is easily and efficiently manufactured.

SUMMARY OF THE INVENTION

0015Accordingly, a compression treatment system is provided having a controller that is adaptable for inflating thigh, calf and foot sleeves or garments and accommodates patient transport and mobility to provide continuous vascular therapy for overcoming the disadvantages and drawbacks of the prior art. Desirably, the system automatically detects the types of sleeves and foot cuffs and combinations connected thereto. Most desirably, the system includes a pneumatic circuit that facilitates pressure monitoring with a single pressure transducer to achieve the advantages of the present disclosure. The compression treatment system is easily and efficiently fabricated.

0016The compression treatment system, in accordance with the principles of the present disclosure, can provide intermittent pneumatic compression for the prevention of DVT. The compression treatment system may also include venous refill detection, as will be discussed, and is compact, quiet, lightweight, and offers battery power. The compression treatment system also has the ability to provide sequential, gradient compression to each limb individually and the flexibility to provide compression to various sleeves, which may, for example, include three bladders. The sleeves may include thigh length tear-away features and knee length sleeves, as will be discussed. In addition, the compression treatment system can provide higher pressure, slow compression to a foot sleeve. The compression treatment system provides uninterrupted DVT prophylaxis as the system is used throughout a treatment facility, and can be worn and used continuously by the patient during the entire period of risk. An example of a tear-away garment is disclosed in U.S. patent application Ser. No. 10/784,706, filed Feb. 23, 2004 and assigned to Tyco Healthcare Group LP.

0017The compression treatment system may be portable to provide continuous therapy for the patient at risk for DVT. This configuration advantageously facilitates continuous vascular therapy during patient activity and tasks such as, for example, transport for testing, bathroom, physical therapy, etc. Thus, the compression treatment system prevents interruptions in therapy by providing a controller that will run on a battery when it is not plugged in, and will also be comfortable, compact, and light enough to move with the patient as needed.

0018The compression treatment system includes a controller, tubing sets, and sleeves. For example, the compression treatment system delivers air through the tubing sets to a pair of disposable sleeves, one for each limb. The sleeves can have three bladders each, which correspond to the ankle, calf, and thigh. The compression treatment system independently compresses one of the limbs, left or right. Inflation is alternated between the two limbs when both are connected. Alternatively, only one sleeve can be connected. It is understood the compression treatment system can detect any combination of garments and number of bladders therein connected to one or more ports.

0019Alternatively, the compression treatment system is used as a slow compression foot device. In this configuration, the compression treatment system includes a pair of single-patient-use, single-bladder disposable foot garments alternative to the sleeves. A single foot garment may also be used. The compression treatment system also provides for employment of a foot garment on a first limb and a sleeve on a second limb.

0020The compression treatment system includes tubing set connector ports that interlock with the mating geometry on the tubing sets. When the compression treatment system is initially powered, air is delivered through the ports until the system recognizes which ports are connected to a sleeve and what types of sleeves, i.e., leg sleeve or foot garment, are connected to those ports. Compression therapy is delivered to the ports with the appropriate sleeves connected.

0021For example, the compression treatment system provides clinical parameters for vascular therapy such as an 11-second inflation cycle, followed by a vent period of 20 to 60 seconds, depending on the venous refill measurement. The 11-second compression time is sequential: at 0 seconds a first bladder starts inflating. At 2.67 seconds a second bladder starts inflating, and at 5.67 seconds a third bladder starts inflating. After 11 seconds, all three bladders vent. The pressures during the inflation period must remain gradient with the first bladder being greater than the second bladder, and the second bladder being greater than the third bladder. By way of example, the end of cycle pressures may be 45 mm Hg in the first bladder, 40 mm Hg in the second bladder, and 30 mm Hg in the third bladder. Compression continues in this cyclical pattern until either the compression treatment system is turned off or the controller alarms.

0022By way of another non-limiting example, the foot compression parameters may include a 5-second inflation cycle followed by the same vent period timing as provided above for the sleeve compression (20-60 seconds). The end of cycle pressure for the foot sleeve will have a set pressure target of 130 mm Hg by the end of the 5-second inflation period.

0023Venous refill detection may be employed with the compression treatment system. Venous refill detection includes trapping a small amount of air in the second bladder described and monitoring the pressure increase as the veins in the limb of a patient refill with blood. As the compression treatment system reaches set pressure, and every 30 minutes thereafter, the controller measures venous refill and adjusts the vent time between inflation cycles for any individual limb from 20 to 60 seconds. The longer of the venous refill measurements from both limbs will be used to adjust the vent time.

0024The compression treatment system benefits from several advantages including a battery powered controller that is compact and lightweight for portability. The compression treatment system may also be used with one or two limbs and can provide slow compression to a foot garment. The compression treatment system can also detect the type of sleeve connected and automatically apply the appropriate compression.

0025The compression treatment system also includes a pneumatic circuit designed for use with the compression treatment system to allow for bladder inflation and pressure monitoring using only one transducer. Pressure monitoring from the manifold-side of the solenoid valves must account for the pressure drop across the valves, but with the added advantage of only requiring one transducer to monitor any connected bladder. This configuration advantageously results in a lower manufacturing cost and reduced maintenance requirements, particularly with regard to transducer calibration.

0026In one embodiment, in accordance with the principles of the present disclosure, the compression treatment system includes a first bladder that is supported about a limb. A second bladder is also supported about the limb. The bladders are in fluid communication with a fluid source and the bladders are inflated such that the first bladder is inflated for a first time period and the second bladder is inflated for a second time period. The second time period is initiated within the first time period. A single pressure sensor communicates with the first bladder and the second bladder. The pressure transducer is configured to monitor pressure of each of the bladders.

0027The compression treatment system may include a controller that communicates with the pressurized fluid source and the pressure transducer. The controller is configured to monitor and regulate pressure in the bladders. The controller may be disposed with a housing that is portable. The housing may include a plurality of ports connectable to a plurality of bladders.

0028The pressure transducer can monitor pressure at each of the plurality of ports to determine if a bladder is connected thereto and sends a representative signal to the controller. The controller may include separate valves that regulate inflation of the bladders. The compression treatment system may define a pneumatic circuit. The pressure transducer may be coupled to the pneumatic circuit and disposed between the pressurized fluid source and the valves in the pneumatic circuit.

0029The compression treatment system may include a third bladder supported about a foot. The third bladder is in fluid communication with the fluid source and the single pressure sensor communicates with bladders. The pressurized fluid source can alternately inflate the bladders disposed about the limb and the bladder disposed about the foot.

0030In an alternate embodiment, the compression treatment system includes a first plurality of bladders that are supported about a first limb. A second plurality of bladders are supported about a second limb, the bladders are in fluid communication with a fluid source. A first bladder of the first plurality of bladders is inflated for a first time period and a second bladder of the first plurality of bladders is inflated for a second time period. The second time period is initiated within the first time period.

0031A first bladder of the second plurality of bladders is inflated for a third time period and a second bladder of the second plurality of bladders is inflated for a fourth time period. The fourth time period is initiated within the third time period. A single pressure sensor communicates with the bladders. The pressurized fluid source may alternately inflate the bladders disposed about the first limb and the bladders disposed about the second limb.

0032In another alternate embodiment, the compression treatment system includes a first plurality of bladders being supported about a first limb and a second plurality of bladders being supported about a second limb. Each bladder of the first plurality of bladders and the second plurality of bladders having a separate valve in communication therewith. The valves are in fluid communication with a fluid source.

0033A first valve is open such that a first bladder of the first plurality of bladders is inflated for a first time period and a second valve is open such that a second bladder of the first plurality of bladders is inflated for a second time period. The second time period is initiated within the first time period. A third valve is open such that a third bladder of the first plurality is inflated for a third time period. The third time period is initiated within the second time period.

0034A fourth valve is open such that a first bladder of the second plurality of bladders is inflated for a fourth time period and a fifth valve is open such that a second bladder of the second plurality of bladders is inflated for a fifth time period. The fifth time period is initiated within the fourth time period. A sixth valve is open such that a sixth bladder of the second plurality is inflated for a sixth time period. The sixth time period is initiated within the fifth time period. A single pressure sensor communicates with the bladders.

0035The objects and features of the present disclosure, which are believed to be novel, are set forth with particularity in the appended claims. The present disclosure, both as to its organization and manner of operation, together with further objectives and advantages, may be best understood by reference to the following description, taken in connection with the accompanying drawings, which are described below.

BRIEF DESCRIPTION OF THE DRAWINGS

0036<figref idref="DRAWINGS">FIG. 1</figref> is a front view of one particular embodiment of a compression treatment system in accordance with the principles of the present disclosure;

0037<figref idref="DRAWINGS">FIG. 1A</figref> is a front view of a control panel of the compression treatment system of <figref idref="DRAWINGS">FIG. 1</figref>;

0038<figref idref="DRAWINGS">FIG. 2</figref> is a side view of the compression treatment system shown in <figref idref="DRAWINGS">FIG. 1</figref>;

0039<figref idref="DRAWINGS">FIG. 3</figref> is a top view of the compression treatment system shown in <figref idref="DRAWINGS">FIG. 1</figref>;

0040<figref idref="DRAWINGS">FIG. 4</figref> is a rear view of the compression treatment system shown in <figref idref="DRAWINGS">FIG. 1</figref>;

0041<figref idref="DRAWINGS">FIG. 5</figref> is a schematic representation of a pneumatic circuit of the compression treatment system shown in <figref idref="DRAWINGS">FIG. 1</figref>;

0042<figref idref="DRAWINGS">FIG. 6</figref> is a plan view of a sleeve of the compression treatment system shown in <figref idref="DRAWINGS">FIG. 1</figref> being disposed about a limb;

0043<figref idref="DRAWINGS">FIG. 7</figref> is an alternate embodiment of the sleeve shown in <figref idref="DRAWINGS">FIG. 6</figref>; and

0044<figref idref="DRAWINGS">FIG. 8</figref> is another alternate embodiment of the sleeve shown in <figref idref="DRAWINGS">FIG. 6</figref>.

DETAILED DESCRIPTION OF THE DRAWINGS

0045The exemplary embodiments of the compression treatment system and methods of operation disclosed are discussed in terms of vascular therapy including a prophylaxis compression apparatus for application to a limb of a body and more particularly in terms of a compression treatment system having a controller that is adaptable for inflating thigh, calf, ankle and foot sleeves and accommodates patient transport and mobility. In particular, the compression treatment system includes a controller, interconnecting tubing, and at least one inflatable garment. The controller includes a pressure transducer, a manifold, and at least one output port adapted for fluidly coupling the controller to the at least one inflatable garment using the interconnecting tubing. The at least one inflatable garment includes at least one inflatable bladder. It is contemplated that the compression treatment system may be employed for preventing and overcoming the risks associated with patient immobility. It is further contemplated that the compression treatment system alleviates the conditions arising from patient immobility to prevent for example, DVT, peripheral edema, etc. It is contemplated that the compression treatment system according to the present disclosure may be attributable to all types of venous compression systems, including, but not limited to a prophylaxis sequential compression apparatus. The term “prophylaxis sequential” shall not be construed as limiting the general venous compression treatment system described herein. It is envisioned that the present disclosure, however, finds application with a wide variety of immobile conditions of persons and patients alike, such as, for example, those undergoing surgery, anesthesia, extended periods of bed rest, obesity, advanced age, malignancy, prior thromboembolism, etc.

0046In the discussion that follows, the term “proximal” refers to a portion of a structure that is closer to a torso of a subject and the term “distal” refers to a portion that is further from the torso. As used herein the term “subject” refers to a patient undergoing vascular therapy using the compression treatment system. According to the present disclosure, the term “practitioner” refers to an individual administering the compression treatment system and may include support personnel. According to the present invention, the term “garment” is a generic term that includes foot cuff, knee sleeve, or leg sleeve. According to the present invention, the term “chamber” and the term “bladder” are used interchangeably.

0047The following discussion includes a description of the compression treatment system, followed by a description of an exemplary method of operating the compression treatment system in accordance with the principles of the present disclosure. Reference will now be made in detail to the exemplary embodiments and disclosure, which are illustrated with the accompanying figures.

0048Turning now to the figures, wherein like components are designated by like reference numerals throughout the several views. Referring initially to <figref idref="DRAWINGS">FIGS. 1-5</figref>, there is illustrated a compression treatment system <b>10</b>, constructed in accordance with the principles of the present disclosure. Compression treatment system <b>10</b> includes a housing <b>12</b>. Housing <b>12</b> encloses the components of a controller <b>14</b> (shown schematically in <figref idref="DRAWINGS">FIG. 5</figref>) disposed therein.

0049Housing <b>12</b> has a semi-circular configuration and has a handle cutout <b>16</b> along its apex <b>18</b> to facilitate transport and subject mobility. It is envisioned that housing <b>12</b> may be variously configured and dimensioned such as, for example, rectangular, spherical, etc. It is further envisioned that housing <b>12</b> may be assembled by any appropriate process such as, for example, snap fit, adhesive, solvent weld, thermal weld, ultrasonic weld, screw, rivet, etc. Alternatively, housing <b>12</b> may be monolithically formed or integrally assembled of multiple housing sections and may be substantially transparent, opaque, etc. Housing <b>12</b> may include ribs, ridges, etc. to facilitate manipulation of compression treatment system <b>10</b>.

0050The components of housing <b>12</b> can be fabricated from a material suitable for medical applications, such as, for example, polymerics or metals, such as stainless steel, depending on the particular medical application and/or preference of a clinician. Semi-rigid and rigid polymerics are contemplated for fabrication, as well as resilient materials, such as molded medical grade polypropylene. However, one skilled in the art will realize that other materials and fabrication methods suitable for assembly and manufacture, in accordance with the present disclosure, also would be appropriate.

0051Housing <b>12</b> is portable to facilitate continuous vascular therapy to a subject (not shown). Housing <b>12</b> includes a bracket <b>20</b> that facilitates releasable mounting of housing <b>12</b> with for example, a hospital bed, table, etc. Bracket <b>20</b> extends from a rear portion <b>22</b> of housing <b>12</b> and provides a hook configuration for suspending housing <b>12</b> from a subject's bed, etc. It is contemplated that bracket <b>20</b> may be suspended from various structure for releasable mounting of housing <b>12</b>, or alternatively, that housing <b>12</b> does not include a bracket and may be placed on a floor or other supporting surface. Alternatively, housing <b>12</b> includes a shoulder strap <b>24</b>, as shown in <figref idref="DRAWINGS">FIG. 2</figref>, that allows housing <b>12</b> to be worn on the subject or practitioner during transport. Shoulder strap <b>24</b> may be employed with or without bracket <b>20</b> and may for example, be secured to any portion of the housing <b>12</b> including handle <b>16</b>.

0052Compression treatment system <b>10</b> employs an electrical AC/DC switching power supply for operation of its components. A power cord <b>26</b> is connected to housing <b>12</b> for conducting power to the components of controller <b>14</b>. Power cord <b>26</b> accesses an AC power supply via a wall outlet, etc. Controller <b>14</b> may include a transformer or other electronics for connecting to the power supply. It is envisioned that power cord <b>26</b> may be wrapped around bracket <b>20</b> for storage and during transport and subject mobility. It is further envisioned that compression treatment system <b>10</b> may include a storage capture mechanism that retains power cord <b>26</b> with housing <b>12</b>. The storage capture mechanism may include an elastic cord, pulley, etc.

0053Compression treatment system <b>10</b> also employs a battery <b>28</b> (<figref idref="DRAWINGS">FIG. 2</figref>) for powering the components of controller <b>14</b> to facilitate transport and subject mobility. Battery <b>28</b> is disposed within a battery compartment <b>30</b> of housing <b>12</b>. It is contemplated that battery <b>28</b> may include one or a plurality of cells. The battery cells may be lithium-ion type, etc. It is further contemplated that battery <b>28</b> is rechargeable and may be employed for various ranges of operation time, such as, for example, 6 hours, 8 hours, 10 hours, etc. For example, power cord <b>26</b> may be unplugged and captured by the storage capture mechanism of housing <b>12</b>. Compression treatment system <b>10</b> then runs on battery <b>28</b> power and the subject is ambulatory.

0054It is envisioned that battery <b>28</b> may be mounted to an exterior surface of housing <b>12</b> or separate therefrom. It is further envisioned that compression treatment system <b>10</b> may include alternate sources of power supply, such as, for example, solar, non-electrical, etc., or alternatively may not include battery power.

0055Housing <b>12</b> has a control panel <b>32</b> disposed on a front surface <b>34</b> thereof (<figref idref="DRAWINGS">FIGS. 1 and 1</figref>A). Control panel <b>32</b> includes controls and indicators for operation of compression treatment system <b>10</b>. Control panel <b>32</b> has an LED display <b>36</b> that provides status indicia, messages, etc. of the various components of system <b>10</b>, such as, for example, power, battery, sleeve identification and connection, inflation, venting, venous refill, errors, etc. In particular, control panel <b>32</b> includes a power switch <b>130</b>, status indicator <b>142</b>, battery level indicator <b>140</b>, port A control <b>132</b>, and port B control <b>134</b>. Port A control <b>132</b> includes a switch <b>136</b> and garment indicators <b>132</b><i>a</i>, <b>132</b><i>b</i>. Similarly, port B control <b>134</b> includes a switch <b>138</b> and garment indicators <b>134</b><i>a</i>, <b>134</b><i>b</i>. Control panel <b>32</b> also includes manually activated switches for powering system <b>10</b>, etc. Specifically, compression treatment system <b>10</b> is energized using power switch <b>130</b> while the operator may confirm the treatment method using switches <b>136</b> and/or <b>138</b> as will be discussed hereinbelow, it is contemplated that such switches are membrane type actuated by finger pressure, etc.

0056Rear portion <b>22</b> of housing <b>12</b> defines ports <b>38</b>, <b>40</b> (<figref idref="DRAWINGS">FIG. 4</figref>). Ports <b>38</b>, <b>40</b> include output ports <b>38</b><i>a</i>, <b>38</b><i>b</i>, <b>38</b><i>c</i>, and output ports <b>40</b><i>a</i>, <b>40</b><i>b</i>, <b>40</b><i>c</i>, respectively. Output ports <b>38</b><i>a</i>, <b>38</b><i>b</i>, <b>38</b><i>c</i>, and output ports <b>40</b><i>a</i>, <b>40</b><i>b</i>, <b>40</b><i>c </i>are in fluid communication with inflatable chambers or bladders <b>46</b><i>a</i>, <b>46</b><i>b</i>, <b>46</b><i>c </i>of a compression sleeve <b>46</b> and inflatable chambers or bladders <b>48</b><i>a</i>, <b>48</b><i>b</i>, <b>48</b><i>c </i>of a compression sleeve <b>48</b>, respectively, which are configured to fit around the legs of a subject, via a mating connector <b>42</b> and tubing set <b>44</b>, as will be discussed. Output ports <b>38</b><i>a</i>, <b>38</b><i>b</i>, <b>38</b><i>c</i>, <b>40</b><i>a</i>, <b>40</b><i>b</i>, <b>40</b><i>c </i>are configured for connection to tubing set <b>44</b>. Each of ports <b>38</b>, <b>40</b> are connectable to a particular compression sleeve or garment, for example, leg sleeve, foot sleeve, etc.

0057Ports <b>38</b>, <b>40</b> are also connected with the components of controller <b>14</b> disposed within housing <b>12</b> to facilitate inflation of selected compression sleeves, as illustrated in the pneumatic circuit shown in <figref idref="DRAWINGS">FIG. 5</figref>. Controller <b>14</b> includes a pressurized fluid source, such as, for example, a pump <b>50</b> that fluidly communicates with a valve manifold <b>52</b> for connection with ports <b>38</b>, <b>40</b>, as will be discussed. Pump <b>50</b> includes a motor that compresses air to valve manifold <b>52</b> via tubing or the like. The speed of the pump motor is electronically controlled to provide a corresponding compressor speed for respective output pressures as desired. Examples of systems including electronically controlled pump motors and associated compressors are disclosed in U.S. Pat. No. 5,876,359 to Bock et al. and U.S. Pat. No. 6,231,532 to Watson et al., both of which are assigned to Tyco Healthcare Group LP and are hereby incorporated by reference in their entirety. It is contemplated that a power supply board, including the necessary electronics, circuitry, software, etc. known to one skilled in the art, is connected to the pump motor and other components of controller <b>14</b> to regulate power thereto. It is envisioned that pump <b>50</b> may be a diaphragm pump.

0058Controller <b>14</b> also includes a check valve <b>54</b> that prevents air leakage back through pump <b>50</b> when monitoring bladder pressure during venous refill detection, as will be discussed. A pressure relief valve <b>56</b> is disposed with the pneumatic circuit to protect against over pressure in the compression sleeves. Pressure relief valve <b>56</b> is configured to bleed excess air pressure if necessary. It is contemplated that various types of valves may be employed such as, for example, spring loaded plunger valves, etc.

0059Check valve <b>54</b> is a mechanical device as is known in the relevant art. In particular, check valve <b>54</b> is disposed between pump <b>50</b>, or an alternate air source, and valve manifold <b>52</b>. Essentially check valve <b>54</b> is disposed between pump <b>50</b> and pressure transducer <b>66</b>. When pump <b>50</b> is energized, pressurized air is provided through check valve <b>54</b> into valve manifold <b>52</b> with minimal restriction to the volumetric flow rate, and then solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>can be opened (i.e. energized) and provide pressurized air to the individual bladders of any garments that have been connected to compression treatment system <b>10</b>. Compression treatment system <b>10</b> is adapted to measure static pressure at one of solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>or attached bladders by turning off (i.e. de-energizing) pump <b>50</b>. Substantially simultaneously, check valve <b>54</b> will automatically close thereby inhibiting the flow of pressurized air to pump <b>50</b> through check valve <b>54</b>. A substantially fluid tight seal is often not achieved by pump <b>50</b> itself, and if pressurized air is allowed to flow back through pump <b>50</b> when it is turned off (i.e. partially venting compression treatment system <b>10</b>), pressure measurements in a connected bladder or in components connected to valve manifold <b>52</b> will be biased by the flow of pressurized air and compression treatment system <b>10</b> will measure the dynamic pressure rather than the static pressure. Furthermore, any leakage of pressurized air through pump <b>50</b> would prevent compression treatment system <b>10</b> from maintaining a constant system pressure with pump <b>50</b> turned off.

0060Using a simple check valve, as opposed to an electrical solenoid valve, offers a number of advantages. The check valve does not require any electrical signals and therefore does not consume any electrical energy, which is especially important when operating on battery power. The check valve does not generate heat like an energized solenoid valve. The check valve is typically much quieter and lighter than a solenoid valve.

0061Valve manifold <b>52</b> includes solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>that are coupled to output ports <b>38</b><i>a</i>, <b>38</b><i>b</i>, <b>38</b><i>c</i>, <b>40</b><i>a</i>, <b>40</b><i>b</i>, <b>40</b><i>c</i>, respectively. Solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c </i><b>60</b><i>b</i>, <b>60</b><i>c </i>each have an associated solenoid that is electrically driven via a control processor of controller <b>14</b>. The solenoid is coupled to a valve seat of each particular solenoid valve <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>such that the seat is operative to open and close the respective solenoid valve upon actuation of the solenoid. See, for example, the solenoid valves described in U.S. Pat. No. 5,876,359 to Bock et al., the entire contents of which is hereby incorporated by reference herein. It is contemplated that the control processor of controller <b>14</b> includes the necessary electronics, circuitry, software, etc. known to one skilled in the art to actuate solenoid valves <b>48</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>in response to varying conditions of compression treatment system <b>10</b> and other indications and measurements sensed by the components of controller <b>14</b>. It is envisioned that one or a plurality of solenoid valves may be employed, or alternatively, that other types of valves may be used.

0062Solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>and their associated valve components are mounted to ports <b>38</b>, <b>40</b> on the interior of housing <b>12</b>. Solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>are two position, three-way normally closed valves, which have openings <b>62</b><i>a</i>, <b>62</b><i>b</i>, <b>62</b><i>c</i>, <b>64</b><i>a</i>, <b>64</b><i>b</i>, <b>64</b><i>c</i>, respectively. In the open position, air flows through openings <b>62</b><i>a</i>, <b>62</b><i>b</i>, <b>62</b><i>c</i>, <b>64</b><i>a</i>, <b>64</b><i>b</i>, <b>64</b><i>c </i>to the associated output port <b>38</b><i>a</i>, <b>38</b><i>b</i>, <b>38</b><i>c</i>, <b>40</b><i>a</i>, <b>40</b><i>b</i>, <b>40</b><i>c </i>and into inflatable chambers <b>46</b><i>a </i><b>46</b><i>b</i>, <b>46</b><i>c </i>of compression sleeve <b>46</b> and inflatable chambers <b>48</b><i>a</i>, <b>48</b><i>b</i>, <b>48</b><i>c </i>of compression sleeve <b>48</b>. In the closed position, openings <b>62</b><i>a</i>, <b>62</b><i>b</i>, <b>62</b><i>c</i>, <b>64</b><i>a</i>, <b>64</b><i>b</i>, <b>64</b><i>c </i>are blocked and air from compression sleeves <b>46</b>, <b>48</b> flows back through output port <b>38</b><i>a</i>, <b>38</b><i>b</i>, <b>38</b><i>c</i>, <b>40</b><i>a</i>, <b>40</b><i>b</i>, <b>40</b><i>c </i>and through vent ports <b>66</b><i>a</i>, <b>66</b><i>b</i>, <b>66</b><i>c</i>, <b>68</b><i>a</i>, <b>68</b><i>b</i>, <b>68</b><i>c </i>of the associated valve to deflate inflatable chambers <b>46</b><i>a</i>, <b>46</b><i>b</i>, <b>46</b><i>c</i>, <b>48</b><i>a</i>, <b>48</b><i>b</i>, <b>48</b><i>c. </i>

0063Solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>are operated in sequence to pressurize inflatable chambers <b>46</b><i>a</i>, <b>46</b><i>b</i>, <b>46</b><i>c</i>, <b>48</b><i>a</i>, <b>48</b><i>b</i>, <b>48</b><i>c </i>and provide sequential pressurization thereof and venting of the chambers under the control processor of controller <b>14</b>. It is contemplated that solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>may be selectively actuated when cooling operation of the sleeves is desired, see for example, U.S. Pat. No. 5,876,359 to Bock et al.

0064Solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>are driven by pulse width modulated signals provided by the control processor of controller <b>14</b>. The solenoid drive signals are initially at a higher power level for rapid and positive actuation of the solenoid valves. After initial actuation, the drive signals can be decreased, for example, by approximately 70% to maintain valve activation, thereby reducing power consumption. It is envisioned that solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>may be deactivated as desired. It is further envisioned that the control processor of controller <b>14</b> includes the ability to verify the status of solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c</i>. As the condition of solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>changes, the control processor verifies their status. For example, if a particular valve is detected to be shorted or open, compression treatment system <b>10</b> will go into a particular error mode, as will be discussed.

0065Controller <b>14</b> also includes a single pressure transducer <b>66</b> disposed within housing <b>12</b>. Pressure transducer <b>66</b> is coupled to the pneumatic circuit and disposed between pump <b>50</b> and solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>via tubing or the like. Pressure transducer <b>66</b> is in fluid communication with inflatable chambers or bladders <b>46</b><i>a</i>, <b>46</b><i>b</i>, <b>46</b><i>c</i>, <b>48</b><i>a</i>, <b>48</b><i>b</i>, <b>48</b><i>c </i>for monitoring pressure in each of inflatable chambers or bladders <b>46</b><i>a</i>, <b>46</b><i>b</i>, <b>46</b><i>c</i>, <b>48</b><i>a</i>, <b>48</b><i>b</i>, <b>48</b><i>c</i>. The control processor (not shown) of controller <b>14</b> directs pressure transducer <b>66</b> to detect or monitor a pressure in any of inflatable chambers or bladders <b>46</b><i>a</i>, <b>46</b><i>b</i>, <b>46</b><i>c</i>, <b>48</b><i>a</i>, <b>48</b><i>b</i>, <b>48</b><i>c </i>that are connected to their respective solenoid valve and thus in fluid communication therewith. Disposing pressure transducer <b>66</b> before the solenoid valves, on the manifold side of the pneumatic circuit, advantageously facilitates use of only a single pressure transducer for measuring the pressure in the inflatable chambers or bladders. This configuration facilitates inflation or pressure measurement of one or a plurality of inflatable chambers or bladders. This configuration also advantageously reduces bulk of controller <b>14</b> to contribute to the compact and lightweight design of compression treatment system <b>10</b>, facilitates transport, patient mobility, and reduces manufacturing costs.

0066In particular, pressure transducer <b>66</b> is disposed downstream of check valve <b>54</b> and upstream of solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>as shown schematically in <figref idref="DRAWINGS">FIG. 5</figref>. As will be discussed in detail hereinafter, by disposing a single pressure transducer <b>66</b> between check valve <b>54</b> and solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c</i>, pressure transducer <b>66</b> is capable of detecting or monitoring a pressure value in one or more of inflatable chambers <b>46</b><i>a</i>, <b>46</b><i>b</i>, <b>46</b><i>c</i>, <b>48</b><i>a</i>, <b>48</b><i>b</i>, <b>48</b><i>c </i>as selected by an operator or controller <b>14</b>. Additionally, pressure transducer <b>66</b> may monitor a static pressure value in manifold <b>52</b> (i.e. solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>are in the closed position and pump <b>50</b> is not supplying pressurized air to manifold <b>52</b>) or a dynamic pressure value in manifold <b>52</b> (i.e. solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>are in the open position and pump <b>50</b> is supplying pressurized air to manifold <b>52</b>). Accordingly, a minimum number of components are required for monitoring pressure values during system <b>10</b> operation.

0067According to an embodiment of the present disclosure, system <b>10</b> is adapted for detecting and monitoring various pressure values. For example, with reference to <figref idref="DRAWINGS">FIG. 6</figref>, as bladder <b>114</b> is being pressurized, system <b>10</b> monitors the pressure of bladder <b>116</b> or <b>118</b>. As mentioned previously, controller <b>14</b> in cooperation with pressure transducer <b>66</b> selects one or more bladders of the attached inflatable sleeves, static system pressure in system <b>10</b>, or dynamic system pressure in system <b>10</b>. Specifically, when measuring a pressure value in an attached sleeve, controller <b>14</b> energizes the solenoid valves associated with that sleeve (i.e. solenoid valves are open) and de-energizes the solenoid valves associated with the other sleeve (i.e. solenoid valves are closed). As such, pressure transducer <b>66</b> is in fluid communication with the bladders of only the selected sleeve and measures the pressure in only that sleeve. Alternatively, system <b>10</b> may detect and/or monitor the pressure in a single bladder of an attached sleeve as follows: controller <b>14</b> energizes the solenoid valve associated with the selected bladder to be monitored while de-energizing the solenoid valves for the remaining bladders. Therefore, pressure transducer <b>66</b> only measures the pressure of a single bladder in a selected inflatable sleeve. Further still, controller <b>14</b> may energize and de-energize different combinations of solenoid valves to detect pressure for the attached inflatable sleeves such that, for example, an average pressure for a sleeve is monitored, an average pressure for both sleeves is monitored, individual bladders in different sleeves are monitored. For example, system <b>10</b> energizes solenoid valve <b>60</b><i>c </i>that is associated with output port <b>40</b><i>c </i>and inflatable bladder <b>48</b><i>c </i>(<figref idref="DRAWINGS">FIG. 5</figref>). Controller <b>14</b> obtains a pressure value from pressure transducer <b>66</b> that corresponds to the pressure value in bladder <b>48</b><i>c </i>in compression sleeve <b>48</b>.

0068Alternatively, controller <b>14</b> may de-energize all the solenoid valves (i.e. closing them all) such that pressure transducer <b>66</b> monitors pressure in system <b>10</b> excluding the inflatable sleeves. This may be done as part of a system leak test, system overpressure test, or other testing as desired. Further still, controller <b>14</b> may energize all the solenoid valves such that pressure transducer <b>66</b> monitors system <b>10</b> pressure including one or more attached inflatable sleeves. This may be done as part of an operational test to monitor dynamic pressure during inflation and/or deflation of the attached inflatable sleeves or during a system leak test.

0069For example, during a selected compression cycle, solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>are sequentially energized to the open position for pressurizing, in sequence, inflatable chambers <b>46</b><i>a</i>, <b>46</b><i>b</i>, <b>46</b><i>c</i>, <b>48</b><i>a</i>, <b>48</b><i>b</i>, <b>48</b><i>c</i>. In the open position, solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>allow passage of air from pump <b>50</b> through the respective output ports <b>38</b><i>a</i>, <b>38</b><i>b</i>, <b>38</b><i>c</i>, <b>40</b><i>a</i>, <b>40</b><i>b</i>, <b>40</b><i>c </i>to the inflatable chambers. Pressure transducer <b>66</b> monitors the pressure of each of inflatable chambers <b>46</b><i>a</i>, <b>46</b><i>b</i>, <b>46</b><i>c</i>, <b>48</b><i>a</i>, <b>48</b><i>b</i>, <b>48</b><i>c </i>of the pneumatic circuit and provides an electrical signal input to the control processor of controller <b>14</b> for feedback control.

0070At the end of the selected compression cycle, solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>are simultaneously de-energized to the closed position for disconnecting pump <b>50</b> from sleeves <b>46</b>, <b>48</b>. In the closed position, pump <b>50</b> air is blocked and solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c</i>, <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>vent sleeve pressure to the atmosphere via vent ports <b>66</b><i>a</i>, <b>66</b><i>b</i>, <b>66</b><i>c</i>, <b>68</b><i>a</i>, <b>68</b><i>b</i>, <b>68</b><i>c </i>on valve manifold <b>52</b>. It is contemplated that compression treatment system <b>10</b> can alternate inflation of the chambers between a first limb and a second limb. It is further contemplated that compression treatment system <b>10</b> can individually inflate each bladder.

0071Referring to <figref idref="DRAWINGS">FIG. 6</figref>, compression treatment system <b>10</b>, similar to that described above, is assembled and packaged for use. In operation, compression treatment system <b>10</b> includes controller <b>14</b> disposed with housing <b>12</b>, described above, and a sleeve <b>112</b>. Sleeve <b>112</b> includes a thigh bladder <b>114</b>, a calf bladder <b>116</b>, and an ankle bladder <b>118</b>. Sleeve <b>112</b> includes a connector <b>120</b> that mates with mating connector <b>42</b>, which is connected to port <b>38</b> via tubing <b>44</b>. Connector <b>120</b> fluidly communicates with the chambers of sleeve <b>112</b> via tubing set <b>122</b>. Thus, this configuration facilitates fluid communication between bladders <b>114</b>, <b>116</b>, <b>118</b> and pump <b>50</b>. It is contemplated herein that connector <b>120</b> may further include a valve mechanism to control fluid flow.

0072Sleeve <b>112</b> is provided and manipulated for disposal about leg L of the subject (not shown). Connector <b>120</b> is mated with mating connector <b>42</b> to establish fluid communication between sleeve <b>112</b> and the pneumatic circuit. Sleeve <b>112</b> is wrapped about leg L and secured thereto via hook and loop pads <b>124</b>, <b>126</b>. It is contemplated that compression treatment system <b>10</b> may treat a second leg of a subject with a compression sleeve, similar to sleeve <b>112</b>, via connection to port <b>40</b>. The second leg is treated in compression cycles alternate to the compression cycles described below for treatment of leg L, as described below in the alternative.

0073The portable features of housing <b>12</b> and controller <b>14</b>, described above, provide a compression treatment system <b>10</b> that facilitates transport and subject mobility. This advantageous configuration provides uninterrupted DVT prophylaxis as the system is used throughout a treatment facility, and can be worn and used continuously by the subject during the entire period of risk. Compression treatment system <b>10</b> advantageously facilitates continuous vascular therapy during subject activity and tasks such as, for example, transport for testing, bathroom, physical therapy, etc. Compression treatment system <b>10</b> prevents interruptions in therapy by providing controller <b>14</b> that will run on battery <b>28</b> when power cord <b>26</b> is not plugged in, and will also be comfortable, compact, and light enough to move with the subject as needed.

0074The manually activated switches of control panel <b>32</b> of controller <b>14</b> switch compression treatment system <b>10</b> on for powering thereof. As compression treatment system <b>10</b> is initially switched on, a series of self-tests are conducted by the control processor of controller <b>14</b>. The LED indicators of display <b>36</b> are illuminated and audible indicia are sounded to verify the operability of the visual and audible indicators. Display <b>36</b> is illuminated to verify display operability. Controller <b>14</b> also verifies operability of the software of the control processor. If any of the verification fails, error codes provide a representative audible and/or visual indicia.

0075It is contemplated that if the control processor of controller <b>14</b> cannot continue normal software execution, an error code will be triggered. This causes compression treatment system <b>10</b> to reset and restart normal operation. Sleeve <b>112</b> would vent during a restart procedure. Audible and visual indicia may also engage to represent the condition.

0076Upon completion of the self-test sequence compression for treatment system <b>10</b>, controller <b>14</b> begins a sleeve detection procedure to determine the type(s) of sleeves or garments attached to ports <b>38</b>, <b>40</b>. Sleeve or garment detection is performed during a first detection cycle after controller <b>14</b> is initially powered on. During the detection cycle, air is delivered alternately through ports <b>38</b>, <b>40</b> with pump <b>50</b> operating for two seconds, or until the pressure reaches a default threshold. After a predetermined amount of time, typically one second later, pressure transducer <b>66</b> takes a pressure measurement to determine whether or not a bladder is connected to a particular output port, <b>38</b><i>a</i>, <b>38</b><i>b</i>, <b>38</b><i>c</i>, <b>40</b><i>a</i>, <b>40</b><i>b </i>or <b>40</b><i>c </i>under sleeve detection.

0077For example, the detection procedure is conducted for bladders <b>114</b>, <b>116</b>, <b>118</b> for each of sleeve ports <b>38</b>, <b>40</b>. If there is no backpressure at a particular outlet port for connection with a bladder, then the control processor of controller <b>14</b> determines that a bladder is not being used with a particular outlet port. The control processor adjusts the compression therapy for the detected sleeve configuration accordingly. For the 3-bladder sleeve, back pressure is detected at bladders <b>114</b>, <b>116</b>, <b>118</b> when connected to controller <b>14</b>. It is contemplated that if no sleeves are detected by this procedure at either port <b>38</b> or <b>40</b>, or if the detected configuration is not recognized, then a low pressure error is triggered with corresponding audible indicia. It is further contemplated that various timing periods may be employed for detection inflation and pressure measurement, according to the requirements of a particular application.

0078Specifically, during the garment detection cycle, system <b>10</b> alternately supplies pressurized air from pump <b>50</b> through ports <b>38</b>, <b>40</b> for identifying if a sleeve is attached to either port and also to identify the type of sleeve attached thereto. As discussed hereinabove, pressurized air is supplied to ports <b>38</b>, <b>40</b>. Illustratively, one port will be discussed in detail with operation of the other port being substantially similar. In particular, pressurized air is supplied to two of output ports <b>38</b><i>a</i>, <b>38</b><i>b</i>, or <b>38</b><i>c </i>for about two seconds or until the pressure reaches a default threshold as measured by pressure transducer <b>66</b>. If no backpressure is measured by pressure transducer <b>66</b> at a selected output port, system <b>10</b> recognizes that the selected output port, and therefore the selected inflatable bladder, is not being used. By way of example, if a foot sleeve is attached to system <b>10</b>, backpressure should only be measured at one of the two selected output ports since the foot sleeve includes one inflatable bladder.

0079Alternately, if a leg sleeve is attached to system <b>10</b>, backpressure should be measured at both selected output ports since the leg sleeve includes at least two inflatable bladders. Therefore, system <b>10</b> identifies the number and types of inflatable sleeves attached to ports <b>38</b>, <b>40</b>. Further still, system <b>10</b> communicates this information to the operator via display <b>36</b>. Visual indicators on display <b>36</b> are illuminated to indicate the number and type of inflatable sleeves attached to system <b>10</b> as identified by system <b>10</b> during the garment detection cycle. In particular, if a foot cuff is attached to system <b>10</b> at either port <b>38</b> or <b>40</b>, system <b>10</b> identifies the foot cuff as discussed above and the respective garment indicator <b>132</b><i>a </i>or <b>134</b><i>a </i>will be illuminated while if a leg sleeve is attached to either port <b>38</b> or <b>40</b>, system <b>10</b> identifies the cuff as discussed above and the respective garment indicator <b>132</b><i>b </i>or <b>134</b><i>b </i>will be illuminated. Therefore, system <b>10</b> provides visual indication to the operator that system <b>10</b> has identified that a foot cuff and/or a leg sleeve is attached. Combinations of a foot cuff and a leg sleeve are contemplated wherein the garment indicator for the identified garment and port combination will be illuminated by system <b>10</b> after the completion of the garment detection procedure. If no sleeves are detected by system <b>10</b> during the garment detection phase, or the detected configuration is not recognized by system <b>10</b>, then a low pressure alarm will be actuated.

0080In one embodiment of the garment detection procedure, pressure transducer <b>66</b> measures the pressure in manifold <b>52</b> after the predetermined inflation time, which is approximately 5 seconds. Pump <b>50</b> is operated for the predetermined inflation time at a constant speed which correlates to a constant input power value of approximately 3 watts. As illustrated in Table 1 below, pressure in manifold <b>52</b> has different values for the type of inflatable garment attached to system <b>10</b> and the number of inflatable bladders in the inflatable garments. The pressures are listed in mm of Hg, but other pressure scales (e.g. torr, psi, etc.) may be used instead.

0081Referring to <figref idref="DRAWINGS">FIGS. 5-8</figref> and Table 1, the detection of a garment will be explained. A single port and valve combination is illustrated with other port and valve combinations operating substantially similar The steps described below can detect bladders <b>114</b>, <b>116</b>, or <b>118</b> (<figref idref="DRAWINGS">FIG. 6</figref>), bladders <b>114</b> or <b>218</b> (<figref idref="DRAWINGS">FIG. 7</figref>) or bladder <b>314</b> (<figref idref="DRAWINGS">FIG. 8</figref>). Upon completion of the self-test sequence, the detection procedure is started. The valves <b>58</b><i>a</i>-<b>58</b><i>c </i>and <b>60</b><i>a</i>-<b>60</b><i>c </i>are venting to the atmosphere. Controller <b>14</b> opens or energizes valve <b>58</b><i>a </i>at port <b>38</b>. The controller <b>14</b> starts the pump <b>50</b> at a predetermined speed to deliver air for a predetermined amount of time through valve <b>58</b><i>a</i>, after which pressure transducer <b>66</b> measures a value of pressure at valve <b>58</b><i>a</i>. If the measured pressure value is at least than 10 mm of Hg, controller <b>14</b> compares the measured pressure to values of pressure stored in controller <b>14</b> (i.e. using a look-up table). If the controller <b>14</b> measures less than 10 mm Hg, the controller <b>14</b> signals there is no bladder connected to valve <b>58</b><i>a</i>. For example, if the measured pressure is greater than 110 mm of Hg, controller <b>14</b> identifies that a knee leg sleeve is attached to system <b>10</b>. If the measured pressure is less than 110 mm of Hg, but not less than 10 mm of Hg, controller <b>14</b> identifies that a thigh leg sleeve is attached to system <b>10</b>. If the measured pressure is greater than 80 mm of Hg, then controller <b>14</b> identifies that a foot cuff is attached to system <b>10</b>. After detection, controller <b>14</b> opens (i.e. energizes) valve <b>58</b><i>a </i>to vent the air in the bladder. Controller <b>14</b> will select a different valve, for example, valve <b>58</b><i>b </i>and repeat the steps mentioned above. <tables id="TABLE-US-00001" num="1"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="1"><colspec colname="1" colwidth="217PT" align="center" /><thead><row><entry namest="1" nameend="1" align="center">TABLE 1</entry></row></thead><tbody valign="top"><row><entry /></row><row><entry namest="1" nameend="1" align="center" rowsep="1" /></row><row><entry>Garment Detection Pressure Measurements</entry></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="2"><colspec colname="OFFSET" colwidth="91PT" align="left" /><colspec colname="1" colwidth="126PT" align="center" /><tbody valign="top"><row><entry /><entry>Garment Types</entry></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="4"><colspec colname="OFFSET" colwidth="91PT" align="left" /><colspec colname="1" colwidth="49PT" align="center" /><colspec colname="2" colwidth="42PT" align="center" /><colspec colname="3" colwidth="35PT" align="center" /><tbody valign="top"><row><entry /><entry>Thigh Length</entry><entry>Knee Length</entry><entry /></row><row><entry /><entry>Sleeve</entry><entry>Sleeve</entry><entry>Foot Cuff</entry></row><row><entry /><entry>Manifold</entry><entry>Manifold</entry><entry>Manifold</entry></row><row><entry /><entry>Pressure</entry><entry>Pressure</entry><entry>Pressure</entry></row><row><entry /><entry namest="OFFSET" nameend="3" align="center" rowsep="1" /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="4"><colspec colname="1" colwidth="91PT" align="left" /><colspec colname="2" colwidth="49PT" align="center" /><colspec colname="3" colwidth="42PT" align="char" char="." /><colspec colname="4" colwidth="35PT" align="center" /><tbody valign="top"><row><entry>Bladder #1</entry><entry>90</entry><entry>130</entry><entry>—</entry></row><row><entry>Bladder #2</entry><entry>70</entry><entry>125</entry><entry>90</entry></row><row><entry>Bladder #3</entry><entry>70</entry><entry>95</entry><entry>—</entry></row><row><entry>Bladder #1 + Bladder #2</entry><entry>45</entry><entry>75</entry></row><row><entry>Bladder #1 + Bladder #3</entry><entry>45</entry><entry>55</entry></row><row><entry>Bladder #2 + Bladder #3</entry><entry>35</entry><entry>60</entry></row><row><entry>Bladder #1 + Bladder #2 +</entry><entry>25</entry><entry>40</entry></row><row><entry>Bladder #3</entry></row><row><entry namest="1" nameend="4" align="center" rowsep="1" /></row><row><entry namest="1" nameend="4" align="left" id="FOO-00001"><br />Garment Detection Measurements (Pressures measured in mmHg after 5 sec inflation @ Pump Power 3 W) <br /></entry></row></tbody></tgroup></table></tables>

0082If a pressure is less than 10 mm of Hg is measured at valve <b>58</b><i>a</i>, then controller <b>14</b> will select valve <b>58</b><i>b </i>and measure a value of pressure at valve <b>58</b><i>b</i>. If the measured pressure is less than 10 mm of Hg at valve <b>48</b><i>b</i>, then controller <b>14</b> determines that no sleeve is attached to port <b>38</b>. Controller <b>14</b> will repeat similar steps for port <b>40</b> using valves <b>60</b><i>a </i>and <b>60</b><i>b</i>. If one or more garments are detected, controller <b>14</b> selects the appropriate compression treatment and waits for user confirmation, as discussed hereinbelow, then controller <b>14</b> begins the compression treatment. If the user confirms the incorrect garment type, then controller <b>14</b> alarms as discussed below. There is no compression treatment during sleeve detection.

0083Furthermore, it is understood that the at least 10 mm Hg pressure measure is experimentally determined and is based upon the pneumatic circuit design (<figref idref="DRAWINGS">FIG. 5</figref>) and selected components therein, such as the pressure transducer <b>60</b>, valves <b>58</b><i>a</i>-<b>58</b><i>a </i>and <b>60</b><i>a</i>-<b>60</b><i>c </i>and interconnecting tubing.

0084Once the garment type is detected at Port A, for example, the operator confirms the garment detected by system <b>10</b>. The user is prompted by the lighted garment indicator (<b>132</b><i>a</i>, <b>132</b><i>b</i>, <b>134</b><i>a</i>, <b>134</b><i>b</i>) on control panel <b>32</b> (<figref idref="DRAWINGS">FIG. 1A</figref>). The user confirms the garment identification by actuating switch <b>136</b> on port A control <b>132</b> once for the leg sleeve (default compression cycle), or actuating switch <b>136</b> a second time for the foot cuff compression. Confirmation of a garment attached to port B is substantially similar. After the user confirms the garment detection, system <b>10</b> initiates a treatment regimen. However, if the operator selected garment does not match the detected garment, then a garment mismatch error is generated for that port that is communicated to the operator via visual and/or audible indicators. Once a garment mismatch error occurs, system <b>10</b> will not initiate a treatment regimen until the operator, using the switches, selects the garment that was detected by system <b>10</b>. Furthermore, the operator, during the garment detection cycle, may manually activate switches disposed on control panel <b>32</b> to select the type of garment (i.e. leg or foot) that is attached to a particular port.

0085Furthermore, the operator, during the garment detection cycle, may manually activate switches disposed on control panel <b>32</b> to select the type of sleeve (i.e. leg or foot) that is attached to a particular port. For a particular port, if the operator selected sleeve matches the sleeve detected by system <b>10</b>, then system <b>10</b> initiates a treatment regimen. However, if the operator selected sleeve does not match the detected sleeve, then a garment mismatch error is generated for that port that is communicated to the operator via visual and/or audible indicators. Once a garment mismatch error occurs, system <b>10</b> will not initiate a treatment regimen until the operator, using the switches, selects the sleeve that was detected by system <b>10</b>. In another embodiment, after the garment detection cycle is complete, system <b>10</b> will not permit the operator to change the type of sleeve attached to system <b>10</b> without restarting system <b>10</b> and repeating the garment detection cycle for the attached sleeves. For example, after the garment detection cycle is complete, if the operator adds a sleeve to an available port, system <b>10</b> will not detect the newly added sleeve and will not perform compression therapy using the newly attached (i.e., undetected) sleeve and will continue to provide the compression therapy for the sleeve detected during the garment detection cycle, while removal of a sleeve will trigger a low pressure alarm from system <b>10</b>.

0086By providing visual and/or audible feedback (i.e. alarms or indicators) during startup, system <b>10</b> also assists in training the operator to select the correct sleeve for a compression therapy session. Specifically, system <b>10</b> reinforces correct selection of the attached sleeve or sleeves by initiating the compression therapy after the garment detection cycle is completed. If the operator selects the wrong type of sleeve for the port, system <b>10</b> will visually and/or audibly alert the operator that a mismatch has occurred. By way of example, if foot sleeves are attached to system <b>10</b>, but foot mode is not selected by the operator, system <b>10</b> will alarm to alert the operator to select the correct mode for the sleeves attached. Over time, the operator will learn to select the correct sleeve during the garment detection cycle so as to prevent system <b>10</b> from alarming and initiating the desired compression therapy once the garment detection cycle is completed. Visual indicators on control panel <b>36</b> are illuminated to indicate the number of garments <b>114</b> and the types of garments (<b>132</b>, <b>134</b>) detected. If no garments are detected by system <b>10</b> or the configuration is not recognized, then a low pressure alarm will sound.

0087Alternatively, compression treatment system <b>10</b> may employ one or more of the following error codes to provide audible and/or visual indicia of system error or failure. These features advantageously enhance safety to the subject during vascular therapy. Several error conditions may cause compression treatment system <b>10</b> to provide alarm and stop a particular compression cycle. It is contemplated that compression treatment system <b>10</b> may flash error indicators, sound continuous signals, etc., causing a user to reset compression treatment system <b>10</b>. Controller <b>14</b> may provide an error alarm for one or more of the following error conditions: incorrect confirmation of the detected sleeve at either port, high pressure error, including those pressures detected in excess of set pressure; low pressure error, including those pressures detected below set pressure and if no sleeves are detected; system pressure error, including pressure determined within an inflation cycle outside of desired parameters; valve error; software error; pump error; vent and deflation error; battery error; and temperature error, including temperatures detected outside of specified environmental conditions.

0088Alternatively, thigh bladder <b>114</b> is removable from calf bladder <b>116</b>. For example, calf bladder <b>116</b> is removably connected to thigh bladder <b>114</b> via a perforated attachment, see, for example, the sleeve described in U.S. patent application Ser. No. 10/784,607 to Tesluk et al., filed on Feb. 23, 2004, the entire contents of which is hereby incorporated by reference herein. For the removable thigh bladder <b>114</b>, the control processor of controller <b>14</b> performs a similar sleeve detection procedure, as described above. The control processor will detect a 3-bladder sleeve due to a flow-restricting valve (not shown) fitted with connector <b>120</b>. See, for example, the flow-restricting valve described in U.S. patent application Ser. No. 10/784,639 to Tordella et al., filed on Feb. 23, 2004, the entire contents of which is hereby incorporated by reference herein. The flow restricting valve simulates the backpressure created by thigh bladder <b>114</b> when there is actually no bladder connected. Thus, the conversion from a 3-bladder thigh length sleeve to a 2-bladder knee length sleeve does not significantly impact the compression parameters, and controller <b>14</b> continues vascular therapy as if thigh bladder <b>114</b> was still intact.

0089In an alternate embodiment, as shown in <figref idref="DRAWINGS">FIG. 7</figref>, sleeve <b>112</b> includes thigh bladder <b>114</b> and a unitary second bladder <b>218</b>. Second bladder <b>218</b> has a calf portion <b>220</b> and an ankle portion <b>222</b>. Pump <b>50</b> fluidly communicates with sleeve <b>112</b> via valve connector <b>224</b> and separate tubing <b>226</b>, <b>228</b>, for employment similar to that described above, including the optional removal of thigh bladder <b>114</b> via perforations or the like.

0090In one particular compression cycle for compression treatment system <b>10</b>, the compression parameters include an 11-second inflation period for inflating bladders <b>114</b>, <b>116</b>, <b>118</b> followed by 60 seconds of venting for deflating bladders <b>114</b>, <b>116</b>, <b>118</b>. The 11-second inflation period is sequential:

00911) initially ankle bladder <b>118</b> is inflated for a first time period starting at 0 seconds;

00922) thereafter and during the first time period, inflation of calf bladder <b>116</b> is initiated for a second time period, the initiation of the second time period coinciding with approximately 2.67 seconds duration of the first time period;

00933) thereafter and during the second time period, inflation of thigh bladder <b>114</b> is initiated for a third time period, the initiation of the third time period at approximately 3.0 seconds duration of the second time period and approximately 5.67 seconds of the first time period; and

00944) after 11 seconds of the first time period, bladders <b>114</b>, <b>116</b>, <b>118</b> vent for a minimum of 20 seconds and a maximum of 60 seconds. An example is illustrated in Table 2 below. <tables id="TABLE-US-00002" num="2"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="OFFSET" colwidth="84PT" align="left" /><colspec colname="1" colwidth="70PT" align="center" /><colspec colname="2" colwidth="63PT" align="center" /><thead><row><entry /><entry namest="OFFSET" nameend="2" align="center">TABLE 2</entry></row><row><entry /><entry /></row><row><entry /><entry namest="OFFSET" nameend="2" align="center" rowsep="1" /></row><row><entry /><entry>Start of Sequence</entry><entry>End of Sequence</entry></row><row><entry /><entry namest="OFFSET" nameend="2" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="4"><colspec colname="1" colwidth="84PT" align="left" /><colspec colname="2" colwidth="70PT" align="center" /><colspec colname="3" colwidth="35PT" align="right" /><colspec colname="4" colwidth="28PT" align="left" /><tbody valign="top"><row><entry>Ankle Compression:</entry><entry>0 seconds</entry><entry>2⅔</entry><entry>seconds</entry></row><row><entry>Ankle/Calf Compression:</entry><entry>End of Ankle</entry><entry> 5/23</entry><entry>seconds</entry></row><row><entry>Ankle/Calf/Thigh</entry><entry>End of Ankle/Calf</entry><entry>11.0</entry><entry>seconds</entry></row><row><entry>Compression:</entry></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="2"><colspec colname="1" colwidth="84PT" align="left" /><colspec colname="2" colwidth="133PT" align="center" /><tbody valign="top"><row><entry>Decompression/Vent:</entry><entry>Minimum 20 seconds, maximum 60 seconds</entry></row><row><entry namest="1" nameend="2" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>

0095It is contemplated that the vent period is measured from the end of one inflation cycle to the beginning of the next inflation cycle on leg L. It is further contemplated that both limbs of the subject may be treated and compression treatment system <b>10</b> alternates vascular therapy from leg L to the second leg. It is envisioned that the time period from the end of the inflation cycle for leg L to the initiation of the inflation cycle for the second leg can range, for example, from 4.5-24.5 seconds.

0096During the initial inflation cycle for treating leg L, as described above, pump <b>50</b> initiates a low default voltage so as to not over-inflate bladders <b>114</b>, <b>116</b>, <b>118</b> on the initial cycle. Solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c </i>are energized to the open position, as described, such that the valves open to deliver air to ankle bladders <b>118</b>, then calf bladder <b>116</b>, then thigh bladder <b>114</b> of sleeve <b>112</b> using a desired cycle timing sequence. Pressure transducer <b>66</b> monitors the pressure in each of bladders <b>114</b>, <b>116</b>, <b>118</b> throughout the 11-second compression cycle. At the conclusion of the inflation cycle, pump <b>50</b> stops and solenoid valves <b>58</b><i>a</i>, <b>58</b><i>b</i>, <b>58</b><i>c </i>de-energize to the closed position to allow bladders <b>114</b>, <b>116</b>, <b>118</b> to deflate through vent ports <b>66</b><i>a</i>, <b>66</b><i>b</i>, <b>66</b><i>c. </i>

0097It is envisioned that if a second leg of the subject is treated for vascular therapy, solenoid valves <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>are energized to the open position, as described, such that the valves open to deliver air to corresponding bladders of a sleeve disposed about the second leg, similar to sleeve <b>112</b>, using a desired cycle timing sequence. Pressure transducer <b>66</b> monitors the pressure in each of the corresponding bladders throughout the 11-second compression cycle. At the conclusion of the inflation cycle, pump <b>50</b> stops and solenoid valves <b>60</b><i>a</i>, <b>60</b><i>b</i>, <b>60</b><i>c </i>de-energize to the closed position to allow the corresponding bladders to deflate through vent ports <b>68</b><i>a</i>, <b>68</b><i>b</i>, <b>68</b><i>c</i>. It is further envisioned that the inflation cycle for treatment of the second leg may be initiated approximately 24.5 seconds after completion of the inflation cycle for treating leg L. This process may be reiterated for cycles pertaining to both legs. Other cycle times are contemplated.

0098In this embodiment, the pressures, as measured by pressure transducer <b>66</b> and the corresponding signal relayed to the control processor of controller <b>14</b>, of bladders <b>114</b>, <b>116</b>, <b>118</b> during the inflation cycle remain gradient with the pressure of ankle bladder <b>118</b> being greater than the pressure of calf bladder <b>116</b>, and the pressure of calf bladder <b>116</b> being greater than the pressure of thigh bladder <b>114</b>. The end of cycle pressures, for example, include 45 mm Hg in ankle bladder <b>118</b>, 40 mm Hg in calf bladder <b>116</b>, and 30 mm Hg in thigh bladder <b>114</b>. An example is illustrated in Table 3 below. It is contemplated that compression continues in this cyclical pattern until either compression treatment system <b>10</b> is turned off or controller <b>14</b> indicates and error code via audible or visual indicia. Other cycles pressures are contemplated. <tables id="TABLE-US-00003" num="3"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="4"><colspec colname="OFFSET" colwidth="70PT" align="left" /><colspec colname="1" colwidth="56PT" align="left" /><colspec colname="2" colwidth="49PT" align="left" /><colspec colname="3" colwidth="42PT" align="center" /><thead><row><entry /><entry namest="OFFSET" nameend="3" align="center">TABLE 3</entry></row><row><entry /><entry /></row><row><entry /><entry namest="OFFSET" nameend="3" align="center" rowsep="1" /></row><row><entry /><entry>Thigh-Length</entry><entry>Knee-Length</entry><entry>Pressure</entry></row><row><entry /><entry>Sleeve</entry><entry>Sleeve</entry><entry>(mmHg)</entry></row><row><entry /><entry namest="OFFSET" nameend="3" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="4"><colspec colname="1" colwidth="70PT" align="left" /><colspec colname="2" colwidth="56PT" align="left" /><colspec colname="3" colwidth="49PT" align="left" /><colspec colname="4" colwidth="42PT" align="center" /><tbody valign="top"><row><entry>Ankle bladder 118</entry><entry>Ankle</entry><entry>Ankle</entry><entry>45 mmHg</entry></row><row><entry>Calf Bladder 116</entry><entry>Calf</entry><entry>Lower Calf</entry><entry>40 mmHg</entry></row><row><entry>Thigh bladder 114</entry><entry>Thigh</entry><entry>Upper Calf</entry><entry>30 mmHg</entry></row><row><entry namest="1" nameend="4" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>

0099For inflation cycles subsequent to the initial inflation cycle for leg L, as described, a pressure feedback adjustment can be made pursuant to the pressure measurement taken by pressure transducer <b>66</b>. At the completion of the initial inflation cycle for leg L, the end of cycle pressure in ankle bladder <b>118</b> is measured by pressure transducer <b>66</b> and compared by the control processor of controller <b>14</b> with the set pressure of 45 mm Hg. If the pressure of ankle bladder <b>118</b> is higher or lower than the set pressure, then a corresponding decrease or increase in the speed of pump <b>50</b> is required to decrease or increase pressure delivery. The pump speed adjustment is based on the following calculation: <br />Adjustment=|45<i>−P</i>|, where P=pressure at the ankle

0100If the pressure is less than the set pressure, then the pump speed for the next cycle is increased by the adjustment amount. If the pressure is greater than the set pressure, then the pump speed for the next cycle is decreased by the adjustment amount. It is contemplated that the adjustment process continues even after the set pressure range is reached. It is further contemplated compression treatment system <b>10</b> may adjust for separate pump speeds for each sleeve connected to controller <b>14</b>. Other sequential compression cycles are also contemplated.

0101In an alternate embodiment, compression treatment system <b>10</b> performs venous refill time measurement. Venous refill time (VRT) measurement is an air plethysmographic technique that determines when the veins of a limb have completely refilled with blood following a compression cycle. See, for example, the venous refill time measurement described in U.S. Pat. No. 6,231,532 to Watson et al., the entire contents of which is hereby incorporated by reference herein. The VRT minimizes the amount of time that the blood remains stagnant inside the veins. The VRT will be substituted for the default rest time (60 seconds) as long as the VRT is between 20 and 60 seconds. If the VRT is less than 20 seconds then the default of 20 seconds is used. If the VRT is greater than 60 seconds then the maximum of 60 seconds is used. The VRT measurement is made when the system first reaches set pressure and once every 30 minutes thereafter. It is contemplated that the VRT technique and algorithm can be used for both sleeve and foot compression.

0102The VRT measurement uses an air plethysmographic technique where a low pressure is applied to the calf bladders. As the veins fill with blood, the pressures in the calf bladders increase until a plateau is reached. The time that it takes for the pressure to plateau is the VRT. If two sleeves are connected to controller <b>14</b>, then the VRT is determined separately for each limb being compressed and the greater of the two measurements is used as the new vent time of the compression cycle. The VRT measurement for each sleeve is made as each particular sleeve reaches set pressure independently. However, the vent time is not updated until VRT measurements have been calculated for both sleeves.

0103For example, compression treatment system <b>10</b> may employ the VRT measurement after the system initiates vascular therapy. Subsequently, after 30 minutes have elapsed, a VRT measurement will be taken on the next full inflation cycle. After any of the sleeves described above inflates, the bladder(s) of the particular sleeve are vented down to zero as in the default inflation cycle.

0104It is contemplated that a selected bladder pressure is monitored and the vent to the bladder is closed when the pressure falls to 5-7 mm Hg. If the pressure in the bladder is 5-7 mm Hg on a current cycle then a VRT measurement is taken. If the pressure in the bladder does not vent down to 5-7 mm Hg then the vent time will remain at its current value and another measurement will be made in 30 minutes. If an error occurs, a corresponding alarm provides audible and/or visual indicia.

0105The VRT measurement algorithm determines when the pressures in the selected bladders plateau after compression. The VRT will be determined separately for both legs. The longer of the two refill times will be used as the new vent time. If compression is applied to only one leg, the VRT for that leg is used as the new vent time. The VRT measurement algorithm initiates with a time counter started from the end of the inflation cycle, which occurs after the selected bladder reaches 5-7 mm Hg (enough pressure to cause the bladder to remain in contact with the surface of the leg) and the venting is stopped. The VRT measurement initiates with the time counter started from the end of the inflation cycle.

0106The pressure in the selected bladder is then monitored. By way of example, the pressure is monitored with a 10-second, moving sample window. The window moves in 1-second intervals. When the difference between the first and last values in the window is less than approximately 0.3 mm Hg the curve has reached its plateau. The VRT measurement is considered done, and the time interval is determined. The end of the window is considered to be the point at which the venous system in the limbs has refilled.

0107Independent of the VRT measurement, the selected bladder is allowed to vent for at least 15 seconds before the next compression cycle on that same limb is started. As a safety factor, 5 seconds are added to the measured refill time so the limb is not compressed too quickly. It is contemplated that the vent time may be equivalent to the measured refill time plus 5 seconds. For example, as a result of patient movement, the standard deviation in the sample window may be too high making the measurement erroneous. At this point, the calculation is discarded and the old value of the VRT is used. The VRT measurement is considered erroneous if at any time during the measurement, the pressure in the selected bladder is below 2 mmHg, the calculation is discarded, and the old value of VRT is used. This may occur if there is a leak in the system. It is contemplated that if the pressure is greater than 20 mmHg at any time during the VRT measurement the old value of the VRT is used. It is further contemplated that if the VRT calculation is done for both legs, the longer VRT of both legs is used. It is envisioned that if the VRT is calculated to be greater than 60 seconds, a value of 60 seconds is used. If the VRT is calculated to be less than 20 seconds, a value of 20 seconds is used.

0108Alternatively, compression treatment system <b>10</b> may employ one, a plurality or all of the following error codes to provide audible and/or visual indicia of system error or failure. These features advantageously enhance safety to the subject during vascular therapy. Several error conditions may cause compression treatment system <b>10</b> to provide alarm and stop a particular compression cycle. It is contemplated that compression treatment system <b>10</b> may flash error indicators, sound continuous signals, etc., causing a user to reset compression treatment system <b>10</b>. Controller <b>14</b> may provide an error alarm for one, a plurality or all of the following error conditions: high pressure error, including those pressures detected in excess of set pressure; low pressure error, including those pressures detected below set pressure and if no sleeves are detected; system pressure error, including pressure determined within an inflation cycle outside of desired parameters; valve error; software error; pump error; vent and deflation error; battery error; and temperature error, including temperatures detected outside of specified environmental conditions.

0109In an alternate embodiment, as shown in <figref idref="DRAWINGS">FIG. 8</figref>, compression treatment system <b>10</b>, similar to that described above, includes a foot sleeve <b>312</b> configured to provide vascular therapy to the foot of the subject. Foot sleeve <b>312</b> includes a bladder <b>314</b> that is inflated with air to provide application of pressure to the foot and then deflated. See, for example, the sleeve described in U.S. patent application Ser. No. 10/784,604 to Gillis et al., filed on Feb. 23, 2004, the entire contents of which is hereby incorporated by reference herein.

0110Pump <b>50</b> fluidly communicates with foot sleeve <b>312</b>. Sleeve <b>312</b> includes a valve connector <b>316</b> that mates with mating connector <b>42</b>, which is connected to port <b>40</b> via tubing <b>44</b>. Valve connector <b>316</b> fluidly communicates with bladder <b>314</b> of sleeve <b>312</b> via tubing <b>318</b>. Thus, this configuration facilitates fluid communication between bladder <b>314</b> and pump <b>50</b>. Foot sleeve <b>312</b> wraps about the side portions of the foot via a hook and loop type connector flap <b>320</b> that transverses the instep of the foot and a hook and loop type connector ankle strap <b>322</b>.

0111Upon completion of the self-test sequence compression for treatment system <b>10</b>, similar to that described, controller <b>14</b> begins the sleeve detection procedure to determine the type(s) of sleeves attached to ports <b>38</b>, <b>40</b>. With regard to foot sleeve <b>312</b>, back pressure is detected by the control processor of controller <b>14</b> corresponding to bladder <b>314</b>, which is connected to outlet port <b>40</b><i>b</i>. It is contemplated that compression treatment system <b>10</b> may treat the foot of a second leg of a subject with foot sleeve <b>312</b> and also treat leg L, as described above, in alternate inflation cycles.

0112In one particular exemplary compression cycle for foot sleeve <b>312</b>, the compression parameters include a 5-second inflation period followed by 60 seconds of venting. An example is illustrated in Table 4 below. <tables id="TABLE-US-00004" num="4"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="OFFSET" colwidth="77PT" align="left" /><colspec colname="1" colwidth="70PT" align="center" /><colspec colname="2" colwidth="70PT" align="center" /><thead><row><entry /><entry namest="OFFSET" nameend="2" align="center">TABLE 4</entry></row><row><entry /><entry /></row><row><entry /><entry namest="OFFSET" nameend="2" align="center" rowsep="1" /></row><row><entry /><entry>Start of Sequence</entry><entry>End of Sequence</entry></row><row><entry /><entry namest="OFFSET" nameend="2" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="1" colwidth="77PT" align="left" /><colspec colname="2" colwidth="70PT" align="center" /><colspec colname="3" colwidth="70PT" align="center" /><tbody valign="top"><row><entry>Foot Compression:</entry><entry>0 Seconds</entry><entry>5.0 seconds</entry></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="2"><colspec colname="1" colwidth="77PT" align="left" /><colspec colname="2" colwidth="140PT" align="center" /><tbody valign="top"><row><entry>Decompression/Vent:</entry><entry>Minimum 20 seconds, maximum 60 seconds</entry></row><row><entry namest="1" nameend="2" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>

0113It is contemplated that the vent period is measured from the end of one inflation cycle to the beginning of the next inflation cycle on the foot of the subject. It is further contemplated that both limbs of the subject may be treated and compression treatment system <b>10</b> alternates vascular therapy from leg L to the second leg. It is envisioned that the time period from the end of the inflation cycle for leg L to the initiation of the inflation cycle for the second leg can range from 7.5-27.5 seconds.

0114During the initial inflation cycle for treating the foot of the subject, as described above, pump <b>50</b> initiates a low default voltage so as to not over-inflate bladder <b>314</b> on the initial cycle. Solenoid valve <b>60</b><i>b </i>is energized to the open position, as described, such that the valve opens to deliver air to bladder <b>314</b> using a desired cycle timing sequence. Pressure transducer <b>66</b> monitors the pressure in bladder <b>314</b> throughout the 5-second compression cycle. At the conclusion of the inflation cycle, pump <b>50</b> stops and solenoid valve <b>60</b><i>b </i>de-energizes to the closed position to allow bladder <b>314</b> to deflate through vent port <b>68</b><i>b. </i>

0115It is envisioned that if a second foot of the subject is treated for vascular therapy, solenoid valve <b>58</b><i>b </i>is energized to the open position, as described, such that the valve opens to deliver air to a corresponding bladder of a foot sleeve disposed about the other leg, similar to foot sleeve <b>312</b>, using a desired cycle timing sequence. For example, pressure transducer <b>66</b> monitors the pressure in the corresponding bladder throughout the 5-second compression cycle. At the conclusion of the inflation cycle, pump <b>50</b> stops and solenoid valve <b>58</b><i>b </i>de-energizes to the closed position to allow the corresponding bladder to deflate through vent port <b>66</b><i>b</i>. It is further envisioned that the inflation cycle for treatment of the second foot may be initiated approximately 27.5 seconds after completion of the inflation cycle for treating the foot treated by foot sleeve <b>312</b>. This process may be reiterated for cycles pertaining to both feet, or in the alternative, for foot sleeve of a first leg and a leg sleeve of a second leg. It is contemplated that compression treatment system <b>10</b> may provide alternating compression to any combination of a sleeve and a foot garment and that if such a combination is employed, then, for example, a 6-second buffer of additional vent timing is added to all vent periods after the foot inflation cycle so that the overall timing is consistent with the default sleeve compression parameters. Other cycles times are contemplated.

0116In this embodiment, the target pressure, as measured by pressure transducer <b>66</b> and the corresponding signal relayed to the control processor of controller <b>14</b>, of bladder <b>314</b> is, for example, 130 mm Hg. It is contemplated that compression continues in this cyclical pattern until either compression treatment system <b>10</b> is turned off or controller <b>14</b> indicates an error code via audible or visual indicia.

0117For inflation cycles subsequent to the initial inflation cycle for foot sleeve <b>312</b> described, a pressure feedback adjustment can be made pursuant to the pressure measurement taken by pressure transducer <b>66</b>. At the completion of the initial inflation cycle for foot sleeve <b>312</b>, the end of cycle pressure in bladder <b>314</b> is measured by pressure transducer <b>66</b> and compared by the control processor of controller <b>14</b> with the set pressure of 130 mm Hg. If the pressure of bladder <b>314</b> is higher or lower than the set pressure, then a corresponding decrease or increase in the speed of pump <b>50</b> is required to decrease or increase pressure delivery. The pump speed adjustment is based on the following calculation: <br />Adjustment=|130<i>−P</i>|, where P=pressure at the foot

0118If the pressure is less than the set pressure, then the pump speed for the next cycle is increased by the adjustment amount. If the pressure is greater than the set pressure, then the pump speed for the next cycle is decreased by the adjustment amount. It is contemplated that the adjustment process continues even after the set pressure range is reached. It is further contemplated that compression treatment system <b>10</b> may adjust for separate pump speeds for each sleeve connected to controller <b>14</b>. Other sequential compression cycles are also contemplated.

0119It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplification of the various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.