This application claims the benefit of U.S. Provisional Patent Application Serial No. 61/144,424 filed 13 January 2009, and entitled "Fluid Flow Augmentation Device and -Methods of Use," which is incorporated herein by reference. This application also claims the benefit of U.S. Provisional Patent Application Serial No. 61/144,425, filed 13 January 2009, and entitled "Method and Apparatus for Increasing Flow in a Body Lumen, " which is also incorporated herein by reference . Field of the Invention The invention generally relates to therapeutic medical devices and methods for increasing the velocity of fluid within body conduits. More particularly, the invention relates to devices and methods for providing intermittent pressure to limbs in order to improve or augment fluid velocity and flow in a patient. Background of the Invention

Deep vein thrombosis (DVT) and pulmonary embolism (PE) constitute major health problems in the United States. It has been estimated that 300,000 to 600,000 hospitalizations a year are attributable to DVT and PE conditions. Venous thromboembolism is also a significant risk in surgical patient populations where preoperative, operative and postoperative immobilization with concomitant loss of venous pump function causes blood stasis.

It is known that the velocity of blood flow in a patient's extremities, particularly the legs, markedly decreases during confinement of the patient. Such pooling or stasis of blood is particularly pronounced during surgery, immediately after surgery, and when the patient has been confined to bed for extended periods of time. It is also known that stasis of blood is a significant cause leading to the formation of thrombi in the patient's extremities, which may have a severe deleterious effect on the patient, including death. Additionally, in certain patients it is desirable to move fluid out of interstitial spaces in extremity tissues, in order to reduce swelling associated with edema in the extremities.

The use of prophylactic antithrombotic drugs for preventing DVT is known. However, the efficacy of prophylactic administration of anticoagulants and antiplatelet agents has been disputed, and is certainly not absolute. An alternative approach, attractive because of its freedom from hemorrhagic side effects, is the use of physical techniques such as elastic stockings, passive leg exercise, electrical calf stimulation and external pneumatic compression of the legs.

Pneumatic compression has been the most studied and appears to be an effective therapeutic technique. For example, the results of a comparison trial between sequential compression and uniform compression are disclosed in an article by E. W. Salzman, et al . , entitled "Effect of Optimization of Hemodynamics on Fibrinolytic Activity and Antithrombotic Efficacy of External Pneumatic Calf Compression," Annals of Surgery, Vol. 206, No. 5, November (1987) , pp. 636-641.

Antithrombotic modalities based on sequential pneumatic compression are also disclosed in articles by J. A. Caprini, et al . , entitled "Role of Compression Modalities in a Prophylactic Program for Deep Vein Thrombosis," Seminars in Thrombosis and Hemostasis, Vol. 14, Supp., Thieme Medical Publishers, Inc., pp. 77-87, (1988) ; and Hull, et al . , entitled "Effectiveness of Intermittent Pneumatic Leg Compression for Preventing Deep Vein Thrombosis After Total Hip Replacement," Journal of the American Medical Association, Vol. 263, No. 17, May, 2, 1990, pp. 2313-2317. Devices for performing sequential compression have also been patented. For example, U.S. Pat. No. 4,013,069 to Hasty, discloses a time-based sequential compression device for coordinated inflation of limb sleeves. Time-based sequential compression devices are also publicly available from The Kendall Company, of Massachusetts. Sequential compression devices and techniques represent the current standard of care for patients requiring fluid flow augmentation.

While sequential compression devices and methods provide for improved blood flow velocity and volumetric flow rate, these improvements come at the expense of patient comfort. Conventional compression devices enclose the limb undergoing therapy. Enclosure of the limb leads to patient discomfort by heat build up and lack of air circulation. Additionally, the limb is strapped into or restrained relative to the compression elements to ensure optimal performance. As a result, the patient is immobilized against the device. The cumbersome and confining nature of the conventional compression therapy devices leads to diminished patient comfort that in turn leads to diminished patient compliance. Thus, while the existing sequential pressure flow therapy is useful in preventing deep vein thrombosis and pulmonary embolism, there continues to be a need for improved flow augmentation devices. Improved flow augmentation devices will provide comparable blood flow velocity and a highly therapeutic prophylactic modality to limbs of patients while also providing enhanced patient comfort. Summary of the Invention

The invention provides systems and methods that move fluid within a body lumen in a body region by providing an array of rollers on a base mutually spaced apart and carried for rotation about parallel axes. Each roller has a roller contact surface that advances into and out of contact with tissue as a result of rotation of the respective roller about its respective parallel axis. The systems and methods support the body region in a holder in association with the array of rollers. The systems and methods drive the array of rollers to individually rotate each roller to cyclically advance the roller contact surfaces into and out of engagement with the tissue region in a synchronized fashion along the fluid flow path to increase fluid velocity in the fluid flow path.

The -systems and methods are well suited for the treatment of deep vein thrombosis and/or pulmonary embolism.

One aspect of the invention provides systems and methods of moving fluid within a body lumen in a body region, e.g., to treat deep vein thrombosis and/or pulmonary embolism. The systems and methods include providing an array of rollers on a base mutually spaced apart and carried for rotation about parallel axes, each roller having a roller contact surface that advances into and out of contact with tissue as a result of rotation of the respective roller about its respective parallel axis. The systems and methods support the body region in a holder in association with the array of rollers such that the axis of the body lumen is orthogonal to the parallel axes of rotation. The systems and methods drive the array of rollers to individually rotate each roller to cyclically advance the roller contact surfaces into and out of engagement with the tissue region in a synchronized fashion along the fluid flow path to increase fluid velocity in the fluid flow path.

Another aspect of the invention provides systems and methods of moving fluid within a body lumen in a body region, e.g., to treat deep vein thrombosis and/or pulmonary embolism. The systems and methods include providing an array of rollers on a base mutually spaced apart and carried for rotation about parallel axes, each roller having a roller contact surface that advances into and out of contact with tissue as a result of rotation of the respective roller about its respective parallel axis. The systems and methods support the body region in a holder in association with the array of rollers with the fluid flow path axially aligned with the parallel axes of rotation of the rollers. The systems and methods drive the array of rollers to individually rotate each roller to cyclically advance the roller contact surfaces into and out of engagement with the tissue region in a synchronized fashion along the fluid flow path to increase fluid velocity in the fluid flow path.

One illustrative embodiment of the invention provides a device sized and configured to improve a flow of fluid in a body conduit. The device includes a drive shaft and at least one roller or auger carried by the drive shaft for rotation about the axis of the drive shaft. Desirably, the device includes an array of rollers. The device includes a receptacle coupled to the base and sized and configured to receive a portion or appendage of the body (e.g., a leg or arm) having a body lumen, in which fluid (e.g., blood) flows. The receptacle holds the body portion in operative association with the roller or rollers, such that the axis of rotation of the roller or rollers extends across (orthogonal to) the blood flow path. In use, synchronized rotation of the roller or rollers induces blood flow in the lumen, desirably in the direction of the heart. The device thus serves to augment or increase venous blood flow toward the heart . In another representative embodiment, a device includes a base, a drive unit supported by the base, and at least one roller coupled to and driven by the drive unit. The device includes a shaft through the at least one roller that is in a fixed position relative to the base. The device includes a receptacle coupled to the base and sized and configured to receive a portion or appendage of the body having a blood flow path toward the heart (i.e., a venous blood flow path) . The receptacle is also sized and configured to position the portion of the body generally orthogonal or transverse to the at least one roller, such that the axis of rotation of the roller is across the venous blood flow path. In some aspects, the device includes a support surface separating the at least one roller from the portion of the body to have improved flow of fluid. In some other aspects, the at least one roller includes a sleeve or cover that may be used alone or in combination with the support surface.

In another representative embodiment, a device includes a proximal support and a distal support that are coupled to the base member. The proximal support and the distal support each desirably include a curved shape sized and configured to receive a portion or appendage of a body to be treated by the device. The geometry of the shape can vary depending upon the body portion being treated. In addition, the device includes a first roller operatively coupled to the drive unit and positioned between the proximal support and the distal support. A first shaft extends through the first roller and is in a fixed position relative to the base member. A second roller is operatively coupled to the drive unit and is positioned between the proximal support and the distal support. There is a second shaft through the second roller and in a fixed position relative to the base member. The first and second shafts rotate about axes that extend across (orthogonal to) the blood flow path through the body portion.

In another representative embodiment, a method includes positioning a body portion having a body conduit into a receptacle configured to receive the body portion so as to support the body portion at a first location and a second location. The method includes maintaining the axis of rotation of a roller in a fixed position between the first location and the second location. The method includes rotating the roller about the axis of rotation to engage the body portion between the first location and the second location. By engaging the body portion, there is movement of fluid from the body portion in the receptacle distal portion towards the body portion in the receptacle proximal portion. The method includes increasing the velocity of the fluid in the body conduit proximal to the receptacle proximal portion.

In another representative embodiment, a device includes a bolster to support a body portion having the body conduit, one or more rollers positioned to engage the body portion, each roller having a projection on its outer surface, and a drive assembly to control the rotation of one or more rollers driven by the drive assembly about an axis of rotation. The bolster or support is sized and configured to position the portion of the body such that the axis of the fluid flow path is axially aligned with the axis of rotation of the rollers. In some aspects, there is a support surface separating the at least one roller from the portion of the body to have improved flow of fluid. In another representative embodiment, a method includes positioning a body portion having a body conduit into a support configured to receive the body portion so as to support the body portion in a position relative to a roller having a projection on its outer surface. The method includes maintaining the axis of rotation of a roller in a fixed position relative to the axis of the body potion receiving therapy and generally along the direction of fluid flow. The method includes rotating the roller about the axis of rotation to engage the body portion with the projection on the roller. By engaging the body portion with the projection, there is movement of fluid from the body portion in the support distal portion towards the body portion in the support proximal portion (or in a direction generally towards the heart) . The method includes increasing the velocity of the fluid in the body conduit proximal to the support proximal portion.

These and other aspects of embodiments of the invention will be made clear by the description and examples that follow.

Brief Description of the Drawings

FIG. IA is a perspective view of a device for improving a flow of fluid within a body conduit without a cover or support surface to separate the rollers from the portion of the body to receive therapy.

FIG. IB is a perspective view of the device of FIG. IA with a cover on each roller and a portion of the housing removed to expose internal roller drive components . FIG. 1C is a perspective view of the device of FIG. IB with additional portions removed to further expose internal roller drive components.

FIG. 2 is a perspective view of a device for improving a flow of fluid within a body having a cover or support surface to over the rollers to separate the rollers from the portion of the body to receive therapy.

FIGS. 3A and 3B illustrate a section view of a device for improving a fluid flow in a leg by synchronizing the engagement of a pair of rollers with a tissue engagement portion below the knee first by a distal roller as shown in FIG, 3A and then by a proximal roller as shown in FIG. 3B.

FIGS. 4A, 4B, 4C and 4D illustrate a section view of a device for improving a fluid flow in a body portion by synchronized engagement of a distal roller and a proximal roller. FIG. 4A illustrates roller position for engagement with a body portion by both the proximal roller and the distal roller. FIG. 4B illustrates roller position for engagement with a body portion having increased engagement with the distal roller and no engagement with the proximal roller. FIG. 4C illustrates a roller position for engagement with a body portion having decreasing engagement with the distal roller and increasing engagement with the proximal roller. FIG. 4D illustrates a roller position for engagement with the body portion having no engagement with the distal roller and an increasing engagement with the proximal roller.

FIG. 5 illustrates an end view of a roller having a rounded peak cross section. FIG. 6 illustrates an end view of a roller having an oblong cross section.

FIG. 7A illustrates a section view of a roller having a circular cross section with a central axis of rotation. FIG. 7B illustrates a section view of the roller in FIG. 7A with a non- central axis of rotation.

FIG. 8A illustrates a section view of a roller having an oblong cross section with a central axis of rotation. FIG. 8B illustrates a section view of the roller in FIG. 8A with a non-central axis of rotation.

FIG. 9A illustrates a section view of a roller having an oblong cross section with a central axis of rotation. FIG. 9B illustrates a section view of the roller in FIG. 9A with a non- central axis of rotation.

FIG. 1OA illustrates a section view of a roller having a rounded triangular cross section with a central axis of rotation. FIG. 1OB illustrates a section view of the roller in FIG. 1OA with a non-central axis of rotation.

FIG. 11 illustrates a section view of a roller having a circular cross section with a non-central axis of rotation. FIG. 12 -is- a perspective view of a device for improving a flow of fluid within a body conduit with the ability to provide an adjustable separation between the rollers.

FIG. 13 is a perspective view of a device for improving a flow of fluid within a body conduit with an adjustable foot support to vary the engagement point of the rollers with a body portion.

FIG. 14 is a perspective view of a device for improving a flow of fluid within a body conduit having an independent drive system for each pair rollers.

FIG. 15 is a perspective view of a device for improving a flow of fluid within a body conduit with a single pair of rollers contacting a portion of the body to receive therapy. FIG. 16 is a perspective view of a device for improving a flow of fluid within a body conduit with a single rollers and a cover or support surface to separate the roller from the portion of the body to receive therapy. FIGS. 17A and 17B illustrate a perspective view of a device for improving a flow of fluid within the body conduit incorporated into a chair.

FIG. 18 illustrates a section view of a device for improving a fluid flow in a leg through the synchronized engagement of three rollers with a tissue engagement portion of the anterior of the leg above the knee first by the distal most roller.

FIG. 19 illustrates a section view of a device for improving a fluid flow in a finger through synchronized engagement of three rollers with the finger.

FIG. 20 illustrates a section view of a device for improving a fluid flow in an arm through synchronized engagement of three rollers with the arm.

FIG. 21 is a perspective view of an alternative embodiment of a device for improving flow in a body lumen .

FIG. 22 is an exploded view of the device for improving flow shown in FIG. 21.

FIG. 23 is an end view of the device for improving flow shown in FIG. 21.

FIG. 24 is a frontal view of a roller with a projection along the roller outer surface.

FIGS. 25A-25D are a sequence of top down views of the device for improving flow shown in FIG.21 showing the movement of the projection as the rollers are rotated.

FIG. 26 is a section view of the device for improving flow shown in FIG.21 with a leg positioned to receive therapy from the rollers in the area of the calf.

Description of the Preferred Embodiments Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims . I. Axis of Rotation Across Blood Flow Path

FIGS. IA, IB and 1C illustrate a perspective view of a device 100 for improving flow of fluid within a body conduit in a portion of a body. The device 100 includes a base 105 and a housing 107. The housing 107 includes various covers and structure to enclose the internal components of the device 100. A receptacle 110 is coupled to the base 105. The receptacle 110 is configured to receive a portion of a body. A drive unit 120 is also supported by the base 105. In FIG. IA, the housing 107 covers the internal components of the device 100. As will be described in the illustrations that follow, the drive unit 120 includes a suitable source of power to operate a motor to drive a suitable transmission scheme to move the rollers 125. At least one roller 125 is coupled to and driven by the drive unit 120. There is a shaft 130 through the at least one roller 125. The shaft 130 is in a fixed position relative to the base 105. In the illustrative embodiment in FIG. IA, there are four rollers 125 two each for each receptacle 110. The components of the device 100 may be fabricated from a variety of commercially available materials and components. For example, the receptacle 110, and base 110 may be formed from wood, plastic, metal or other suitable materials .

The receptacle 110 includes a distal support 112 and a proximal support 114. The supports 112, 114 and the receptacle 110 may have shaped surfaces or features 111 to accommodate the body portion being treated by the device 100. The shape 111 comports to various aspects of the leg in the embodiments of FIGS. 1A-4D, 15, 16, 17A, 17B, and 18. The receptacle 110 and/or shape 111 may also be used to conform the device to other body portions such as a finger (FIG. 19) or an arm (FIG. 20) . The size, shape, dimensions, spacing and structural characteristics of the receptacle 110, the shape 111 and the rollers 125 may be adjusted depending upon the body portion, the conduit and the fluid flow to be improved by the device.

FIG. IB is a perspective view of a device similar to that of FIG. IA. Portions of the housing 107 have been removed to reveal some of the internal components of the device 100. Similarly, FIG. 1C is a perspective view of the device of FIG. IB with additional portions removed to further expose internal roller drive components. The components of the drive system 120 will vary depending upon the type of drive system used. The drive unit 120 may include any of a number of conventional components for the conversion of rotation in a drive system to rotation of the at least one roller 125. The drive unit 120 is controlled by one or more switches or control knobs (not shown) . Power is provided to the device 100 using a conventional power cord and plug. The switches or control knobs may be mounted for ease of access to a person using the device.

In the exemplary system of FIGS. IB and 1C, the drive system is a gear drive. A motor 160 is coupled to an output shaft (not shown) . The output shaft engages with a series of spur gears 164a, 164b, 164c and 164d to rotate a drive shaft 166. The drive shaft 166 in turn rotates the bevel gears 168a, 168b to drive shaft 130. Pulleys 172 on the shaft 130 are connected by a belt 170. This is one example- of a drive unit 120 operating a motor to power a gear train and produce rotation of the rollers. In this exemplary embodiment, one motor drives the gear train to rotate the first shaft 130 that is coupled to two rollers 125. That first shaft 130 drives a second pair of rollers 125 on a second shaft 130 using the pulleys 172 and belt 170. The first pair of rollers 125 are closest to the drive unit 120 and the distal support 112. The second pair of rollers 125 (driven by- belt 170) are closest the proximal support 114. Different gear configurations, belt or pulley drives or direct drive systems are possible based on the body portion to be treated with the device and the transmission scheme used to impart motion to the roller or rollers 125.

In contrast to FIG. IA, the embodiments of FIGS. IB and 1C illustrate an optional covering 127 on the rollers 125. The covering 127 may be used to adjust the surface properties of the roller 125. The cover 127 may be a sleeve shaped to fit over the roller 125. The roller 125 may have a smooth outer surface and then be provided a different surface based on the properties and characteristics of the cover 127. The cover 27 may be padded, have ridges, bumps or other features to enhance the effectiveness of the engagement of the roller with the body portion.

FIG. 2 is a perspective view of a device 100 for improving a flow of fluid within a body having a cover or support surface 115 over the rollers 125 to separate the rollers 125 from the portion of the body to receive therapy via operation of the device 100. There are two receptacles 110 shown. The receptacles 110 are shaped 111 to receive the body portion to be treated by the device. The support surface 115 is shown with a deflection 109. The deflection 109 is caused by the repeated movement of the roller 125 to cyclically engage with and deflect the support surface 115 and in turn the body portion adjacent the support surface 115. The support surface 115 is formed from any of a number of flexible materials suited to supporting the portion of the body to have improved flow. The support surface may be formed from a flexible material such as fabric, web, plastic film, or the like. In this example, the receptacles 110 are designed to support the feet at the closed end in such a position that the rollers below the surface 115 will engage in the desired location on the leg. The device 100 will be placed so that the deflection 109 and the synchronous action of the rollers 125 (if more than one roller is used) will interact with the targeted portion of the body based on the conduit and fluid to be moved. In one case, the rollers 125 will engage in a posterior aspect of the leg below the knee without contacting the Achilles tendon. This is a general description of the calf area. The calf area is a target site for increasing the venous flow velocity augmentation in the veins in the calf and veins of the "upper" leg, such as popliteal vein, femoral vein and iliac vein. As such, in order to match the patient anatomy and the target conduit to the device

100, the receptacle 110 may be formed in various sizes or may be adjustable. For example, the foot support may be moved between several different locations to vary the interaction between the device and the target site on the patient. An exemplary adjustable device is shown in FIG. 13. The device 100 illustrated in FIG. 13 is an example of a device having an adjustable receptacle. The receptacle 110 includes a plurality of slots 190 to allow a foot support to be placed between the slots 190 so that the rollers 125 will engage the targeted site. Another exemplary adjustable device is shown in FIG. 12. The device 100 in FIG. 12 has a moveable drive train that allows for adjustment the spacing and location of the rollers 125. In this way, the interaction between the rollers and the target location on the body or the targeted conduit or fluid may be adjusted.

FIGS. 3A and 3B illustrate a section view of a device for improving a fluid flow in a leg by synchronizing the engagement of a pair of rollers with a tissue engagement portion below the knee first by a distal roller as shown in FIG, 3A and then by a proximal roller as shown in FIG. 3B. The device 100 includes a base 105, housing 107 and a receptacle 110 coupled to the base 105. The receptacle 110 is configured to receive a portion of a body that is, in this example, a leg 3. In this illustrative example, the portion of a body is the leg 3, shown in phantom. The leg 3 is supported by the support surface 115 that separates the leg 3 from the rollers 125. The leg 3 includes the ankle 12, the calf 6, the knee 9 and the thigh 7. The foot 15 is positioned at the distal end of the receptacle supported by the receptacle distal support 112. The thigh 7 is positioned at the proximal end of the receptacle and is supported in part by the proximal support 114. The weight of the leg 3 is borne at least in part by contact with the rollers 125. The drive unit 120 that imparts rotation 50 about the shaft 130 is not shown in the views of FIGS. 3A and 3B but is described elsewhere in this application.

In the coordinated operation of the device is shown in FIGS. 3A and 3B, the body portion to be treated is placed in the receptacle 110 and against the support surface 115. The roller spacing or leg position may be adjusted as needed to ensure that the rollers 125 contact the tissue only in the tissue engaging zone 140. Activation of the drive unit produces roller 125 rotation 50 about shaft 130. At least one roller 125 is coupled to and driven by the drive unit. The at least one roller 125 is separated by the support surface 115 from the portion of the body to have improved fluid flow. FIGS. 3A and 3B illustrate the position of the leg 3 relative to the device 100. Importantly, the position of the roller 125 or rollers 125 depends upon the body- portion to be treated and the flow to be improved. FIGs. 3A and 3B illustrate one possible device configuration for improving venous return or increasing the velocity of venous flow from the leg 3. The rollers 125 (two are shown in this embodiment) are positioned in order to have primary contact with the posterior aspect of the leg below the knee 9 and above the Achilles tendon. The zone for engaging tissue 25 indicates the general area of contact between the rollers 125 and the posterior aspect of the leg 3. The tissue engaging zone 25 is selected to target the concentration of large veins found in the posterior leg or area of the calf 6. Importantly, there are no rollers 125 in the avoidance areas 20. The distal avoidance zone 20 includes the foot 15, ankle 12, heel and the leg below the Achilles tendon. It is believed that the roller contact with these areas does not contribute sufficiently to increasing venous return or increasing the velocity of fluid return. Additionally, roller contact in the posterior leg near the Achilles tendon often produces patient discomfort. Similarly, the proximal avoidance area 20 includes the tendons in the posterior aspect of the knee 9. Roller contact with this area may also produce patient discomfort. The position of rollers 125 shown in FIGs. 3A and 3B illustrate one possible placement to increase venous velocity and return from the calf 6.

FIGS. 3A and 3B also illustrate rollers with an egg shaped cross section shape. As shown, the rollers 125 have an engagement surface portion 135. As the roller 125 rotates about axle 130 as indicated by arrow 50, the roller engagement portion 135 will alternately engage and disengage with the portion of the body adjacent the roller as shown. Advantageously, the contact points or surface 135 of each roller 125 will, during rotation 50, contact the support surface 115 and the posterior aspect of the leg 3 within the engaging zone 25. The size of and spacing between the rollers 125 produces contact points 135 which are displaced from each other along the engaging zone 25. Additionally, the shaft 130 may be moved relative to the support surface 115 or the body- portion to also vary the amount of contact. In the illustrative embodiments of FIGs. 3A and 3B the shafts 130 are the same height above the base 105. The shafts 130 may be at different heights, the proximal shaft may be higher or lower than the distal shaft or in any position relative to one another in order to produce the desired flow augmentation. As a result, the drive unit and drive train or transmission produces coordinated angular movement of each roller 125 to provide improved flow within the engagement zone 25.

As shafts 130 are rotated by the drive unit, the roller contact surface 135 moves into and out of contact with the tissue, muscles and fluid conduits in engaging zone 25 of the leg 3 in a cyclical sequence with the rollers acting in synchrony. If the roller contact surfaces 135 may be displaced in virtually any angular increment based on roller shape, size and spacing. The rotation of shaft 130 will cause the roller contact surfaces 135 to be lifted in wave-like motion which provides a kneading action along the length of the posterior aspect of the leg 3 within the engagement zone 25 against the calf 6. Coordination of the roller 125 and contact surface 135 motion ensures that the fluid motion enhancement caused by one roller/contact surface is furthered by the next roller/contact surface and so on as shown my the flow line 60 (in phantom) .

FIGS. 3A and 3B illustrate an example of coordinated roller 125 action. FIG. 3A shows the distal most roller 125 in zone 25 engaging with tissue to produce a distal deflection 109a. Next, in FIG. 3B, the proximal roller 125 engages tissue after the distal most roller has stopped contact with the tissue. The motion of the proximal roller 125 produces the proximal deflection 109b.

The tissue engaging action of the roller contact surfaces 135 may be changed by increasing or decreasing the speed of the drive unit. Additionally or alternatively, changing the shape and size of the roller 125, the shape and size of the roller engagement surface 135, the location of the axis of roller rotation and speed of roller rotation may be used to produce a variety of different tissue engagement actions or sequences. Moreover, the tissue engagement action performed in the engagement zone 25 may be changed by using roller contact surfaces 135 of different configurations to provide different body portion or tissue engagement periods (how long the surface 135 engages the tissue) , tissue engagement forces (how much force is applied to the tissue by the roller engagement surface) and tissue engagement force profiles (the rate at which the force is applied to the tissue) . The shape of each roller contact surface 135 may be the same or different from the other surfaces 135 in the device 100. In one aspect, the contact surfaces 135 are arranged and driven to provide a sine or cosine pattern to the movement of the support surface 115 and body portion engaged by the device 100.

FIGS. 4A, 4B, 4C and 4D illustrate a section view of a device 100 for improving a fluid flow in a body portion by synchronized engagement of a distal roller 125 and a proximal roller 125. The illustrated drive unit 120 has a motor 160 with an output shaft 162. The output shaft 162 rotates spur gears 164a, 164b, 164c and 164d that in turn rotate the drive shaft 166. The drive shaft 166 rotates bevel gears 168a and 168b to produce rotation of the proximal shaft 130. Proximal shaft rotation is transferred to distal shaft rotation using belt 170 and pulleys 172 on the shafts 130. The device 100 embodiment illustrated in FIGS. 4A-4D also shows how the operating characteristics of the device may vary based upon, for example, the relative locations of the rollers 125, the roller shafts 130, and the proximal and distal supports 114, 112. The shaft 130 is located in a position relative to the roller 125 that is not in the central portion or along the center of the roller 125. The roller rotation appears as shown in FIG. 11. As the roller 125 moves from the highest point (the position in solid line) to the lowest point (the position in the dashed line) , the roller contact area 135 moves through a change in height (indicated by Δh) . The amount of height change depends on a number of factors such as the size of the roller and the position of the shaft 130 relative to roller's center of rotation. As illustrated by FIGS. 4A-4C, the off axis rotation of the roller 125 contributes to the production of deflection 109. Moreover, the proximal shaft 130 (nearest to the _^ drive unit 120) is at a height hi above the base 105. The distal shaft 130 (closest to the proximal support 114) is at a height h2 from the base 105. The relative position of the shafts 130 to one another and to the base also contribute to the amount of deflection 109. The proximal support 112 is at a height hsl relative to the base 105. The distal support 114 is at a height hs2 relative to the base 105. The supports may be at the same height above the base (see FIGs. 3A and 3B) or at different heights as shown in FIGs. 4A-4D. The parameters of a device may be selected to conform to a specific body part. In the embodiment of FIGs. 4A- 4D, the support heights hsl and hs2 along with the roller shaft heights hi and h.2 are selected to accommodate the posterior aspect of the leg, specifically the calf. In one aspect, the roller movement produces a deflection 109 in the range of 0.5 inches to 2 inches. The synchronous operation of the rollers 125 will now be described with reference to FIGS. 4A-4D. FIG. 4A illustrates roller 125 position for engagement with a body portion by both the proximal roller and the distal roller. As a result, the support surface 115 is deflected by both distal deflection 109a from the distal roller 125 and proximal deflection 109b from the proximal roller 125. FIG. 4B illustrates increased engagement with the distal roller and no engagement with the proximal roller. FIG. 4B illustrates the distal roller 125 in position for further engagement with a body portion as evidenced by the increase in distal deflection 109a as compared to the amount of distal deflection 109a in FIG. 4A. FIG. 4B also illustrates how continued rotation of the proximal roller 125 reduces or eliminates the proximal deflection 109b when compared to "FIG. 4A. FIG. 4C illustrates a roller position for engagement with a body portion having decreasing engagement with the distal roller and increasing engagement with the proximal roller. FIG. 4C illustrates how the continued rotation of the rollers 125 reduces the distal deflection 109a and increases the proximal deflection 109b. FIG. 4D illustrates a roller position for engagement with the body portion having no engagement with the distal roller and an increasing engagement with the proximal roller. FIG. 4D illustrates how the continued rotation of the rollers 125 reduces or eliminates the distal deflection 109a while increasing the proximal deflection 109b. As the cycle repeats back to FIG. 4A, the proximal roller 125 will engage with the tissue to be treated and begin the initial proximal engagement with the tissue. As the proximal roller engagement peaks (FIG. 4B) and begins to diminish the proximal roller engages (FIG. 4C) . Next, the proximal roller moves on to maximum engagement while the distal roller is not engaged (FIG. 4D) . Numerous roller designs and configurations are possible. FIGS. 5-11B illustrate some of the alternative configurations for rollers 125.

FIG. 5 illustrates an end view of a roller 125 having a rounded peak cross section. In most configurations, the roller contact area 135 will engage with targeted tissue once each revolution at least the 12 o'clock position. Depending upon the physical make up of a device 100, a roller may begin to engage tissue over a range of values and with varying degrees of pressure applied to the tissue and involved conduits. One factor in the determining the degree of engagement with the tissue is by the amount of displacement Δh of the engagement surface 135 at maximum displacement. Another factor is at what point during roller rotation does the engagement surface 135 actually engage the tissue and involved conduits.

FIG. 6 illustrates an end view of a roller 125 having an oblong cross section. Depending upon design criteria, this roller may have at least two tissue engagement surfaces 135. In one aspect, the roller 125 may have tissue engagement each time an engagement surface 135 passes the 12 o'clock position. In this case, the roller 125 would engage tissue and conduits twice per revolution. One factor in the determining the degree of engagement with the tissue is by the amount of displacement Δh of the engagement surface 135 at maximum displacement. Another factor is at what point during roller rotation the engagement surface 135 actually engages the tissue and involved conduits. In another aspect of the embodiment of FIG. 6, the entire rotation of the roller may be considered the roller engagement surface 135. In this aspect, when the roller is in the 12 o'clock position as shown in solid lines, then the roller engagement surface 135 is at maximum tissue and conduit contact. Next, as shown in phantom or dashed lines, the roller short axis is an engagement surface or the minimum engagement surface during part of the roller rotation. As rotation continues, the long end of the roller moves towards the 12 o'clock position with increasing pressure application and engagement with the tissue and conduits.

Based on these similar principals of shape, position, axis of rotation and proximity to the targeted engagement tissue, one of ordinary skill will appreciate that a wide variety of roller designs may be utilized in the ^' device 100.

FIG. 7A illustrates a section view of a roller 125 having a circular cross section with a shaft 130 positioned to produce a central axis of rotation. FIG. 7B illustrates a section view of the roller 125 of FIG. 7A with' a shaft 130 positioned to produce a non-central axis of rotation.

FIG. 8A illustrates a section view of a roller 125 having an oblong cross section with a shaft 130 positioned to produce a central axis of rotation. FIG. 8B illustrates a section view of the roller 125 in FIG. 8A with a shaft 130 positioned to produce a non-central axis of rotation.

FIG. 9A illustrates a section view of a roller 125 having an oblong cross section with a shaft 130 positioned to produce a central axis of rotation. FIG. 9B illustrates a section view of the roller 125 in FIG. 9A with a shaft 130 positioned to produce a non-central axis of rotation. FIG. 1OA illustrates a section view of a roller having a rounded triangular cross section with a shaft 130 positioned to produce a central axis of rotation. FIG. 1OB illustrates a section view of the roller 125 in FIG. 1OA with a shaft 130 positioned to produce a non- central axis of rotation.

FIG. 11 illustrates a section view of a roller 125 having a circular cross section with a shaft 130 positioned to produce a non-central axis of rotation.

Rollers 125 are attached to a shaft 130 that is driven by a drive unit 120 (not shown) . The drive unit

120 includes an electric motor provided for rotating cam shaft (not shown) . The cam shaft may be driven directly by a motor or through an arrangement of belts and pulleys, or gears, etc as described below. FIG. 12 is a perspective view of a device 100 for improving a flow of fluid within a body conduit with the ability to provide an adjustable separation between the rollers 125. As with earlier embodiments, portion of the housing 107 have been removed to expose the internal workings of the device 100. The drive unit 120 includes a motor 160 coupled to bevel gears 168a, 168b. Operation of the motor 160 results in rotation of shaft 130 and the first pair of rollers 125. Rotation of the first shaft

130 also rotates the first pulley 172 that in turn moves belts 172 drive the second pulley 172 and the second roller 125.

Device 100 of FIG. 12 provides a ^' roller drive assembly that enables adjustable spacing for the rollers 125. As shown in phantom in FIG. 12 the shaft 130 may be moved to alter the lateral separation of the _. rollers 125. The belt 170 may be flexible to stretch into the required length. Alternatively, the belt 170 will be selected after the spacing between the shaft 130 is selected for the needs of the specific patient. The housing 107 may be modified to accommodate various shaft 130 positions and sliding shaft positions or appropriate bearing assemblies may be added, as needed, to support the selected shaft 130 position. Additionally or alternatively, the motor 160, the bevel gears 168a, 168b and the driven shaft 130 may be positioned on a sliding support (not shown) . The sliding support and associated openings in the housing 107 will allow movement of the first roller and to position. Thereafter, the second roller may be moved into position and driven by the belt 170 and the pulleys 172. Other modifications to the position of shaft 130 for other horizontal, and/or lateral spacing between the rollers 130, the roller 130 and the base 105 and/or a roller 130 and the housing 107 are possible using conventional mechanical components to support the shaft 130, the motor 160 and the bevel gears 168a, 168b.

FIG. 13 is a perspective view of a device 100 for improving a flow of fluid within a body conduit with an adjustable foot support to vary the engagement point of the rollers 125 with a body portion. FIG. 13 illustrates a perspective and cutaway view of another embodiment of a device 100 for improving flow of fluid within a body conduit. As with earlier embodiments, portion to the housing 107 have been removed to expose internal workings of the device 100. The drive unit 120 includes a motor (not shown) that drives and output shaft 162. The output shaft 162 is coupled to the drive gear 184. A drive belt or chain 182 is engaged with the device care 184 or the output shaft as well as each roller gear 186. Each roller gear 186 is attached to a roller shaft 130. Operation of the drive unit 120 produces rotation of the output shaft

162 and corresponding rotation of the rollers 125 through the belt or chain drive 182 and the drive gears 184, 186.

The embodiment of the device 100 illustrated in FIG.

13 provides another form of adjustability for the device to engage with a patient's specific physiology. In the embodiment of figure 13, adjustability takes the form of fixed roller spacing with adjustable foot supports in the receptacle 110. As shown in figure 13 the user workplace a foot along the back vertical wall of the receptacle 110. If that foot position did not align the target treatment site with the rollers, a foot support (not shown) would be used. A foot support, sized to span the receptacle 110 between two slots 190, would be added between two slots 190. The added foot support would be moved as needed in order to adjust the foot position in the receptacle 110 to modify the roller contact point for that patient. Alternatively, instead of slots and a foot support, a portion of the receptacle 110 could be mounted on a sliding or adjustable platform similar to those used on exercise equipment. In this way the foot support alone or with a portion of the receptacle 110 may be slid or adjusted to vary the distance between the foot support and the roller contact area.

FIG. 14 illustrates a perspective view of another embodiment of a device 100 for improving a flow of fluid within a body conduit. As with earlier embodiments, portions of the housing 107 have been removed to expose the internal workings of the device 100. Rather than a single motor 160, the embodiment of FIG. 14 utilizes two motors 161 each to drive a pair of rollers 125. Each motor 160 rotates and output shaft worm gear 188a that engages with a roller shaft worm gear 180b. In this embodiment, the drive unit 120 also includes controls to synchronize the operation of each motor 162 to accomplish the desired amount flow improvement.

FIG. 15 is a perspective view of a device for improving a flow of fluid within a body conduit with a single pair of rollers and without a cover or support surface to separate the rollers from the portion of the body to receive therapy. As with previous embodiments, portions of the housing 107 have been removed to expose portions of the internal workings of the device 100. The device 100 of FIG. 15 is of similar construction to the device 100 of FIGS. IA- 1C except that only a single roller shaft 130 is driven by the drive unit 120. As a result, only a single roller 125 is provided to each body portion in contrast to the two rollers per body portion in the embodiments of FIGS. IA - 1C.

Still further alternative embodiments are possible. In one aspect, the motor that drives a roller is located inside of the roller. The motor may be used to drive only a single roller or may used any technique described herein or other conventional gearing and drive systems to control the rotation of one or more additional rollers. FIG. 16 is a perspective view of a device 100 for improving a flow of fluid within a body conduit with a single roller pair and a cover or support surface to separate the roller from the portion of the body to receive therapy. In the embodiment of FIG. 16 the housing 107 and receptacle 110 or configured for a single body portion. Other detailed aspects of the device 100 such as, for example, the cover 115, curvature 111, number of rollers and the device system may be modified as described herein according to the needs of the flow improvement being undertaken.

The previous embodiments have illustrated an embodiment of the flow improvement device 100 may be utilized as a standalone component suited to placement on a floor, a bed or in another placement suited to patient use. However, is to be appreciated that the device 100 is not so limited. The flow improvement device 100 embodiment may be integrated into a chair. It is well- documented that blood flow in the lower extremities is often adversely impacted by long-duration air travel. FIGS. 17A and 17B illustrate a perspective view of a device 100 for improving a flow of fluid within the body- conduit incorporated into a chair that is an aircraft passenger chair 200. In the illustrated examples, the chair is a chair 200 used in an airplane. The device 100 may be used or adapted for use on an airline by- incorporating its controls into the chair controls and power provided by the aircraft power system. To enhance patient comfort and address roller contact positions, the device 100 may be mounted on a user controlled adjustable support 205 as shown in FIG. 17A. Alternatively, the device 100 may be simply integrated into the chair 200 as shown in FIG. 17B.

FIG. 18 illustrates a section view of a device for improving a fluid flow in a leg 3 through the synchronized engagement of three rollers 125 with a tissue engagement portion of the anterior of the leg above the knee. The tissue engaging zone 25 is found generally in the area of the thigh 7. Three rollers 125 are shown in the zone for engaging tissue 25. The distal roller is shown engaging tissue. The middle roller is shown with a tissue engaging surface 135 near the 4 o'clock position. The proximal roller is shown with a tissue engagement surface 135 near the 8 o'clock position. In one aspect, the tissue engaging zone 25 is selected to enhance roller 125 contact with the veins located in the quadriceps.

Operation of the device 100 in FIG. 18 would follow the earlier example of the coordinated roller 125 action described above in FIGS. 3A and 3B. FIG. 18 shows the distal most roller 125 in zone 25 engaging with tissue and producing the distal deflection 109a in the support surface 115 and related tissue, muscle and conduits in the thigh 7. Continued operation of the device 100 will result in the middle roller 125 engaging tissue in zone 25 proximal to the tissue engaged by the distal roller. The middle roller will produce a corresponding deflection 109 associated with its movement. In one aspect, the middle roller 125 engages tissue in zone 25 after the distal most roller has stopped and/or reduced contact with the tissue. Continued operation of the device 100 will result in the proximal roller 125 engaging tissue in zone 25 proximal to the tissue engaged by the middle roller 125. The proximal roller will produce a corresponding deflection 109 associated with its movement. In one aspect, the proximal roller 125 engages tissue in zone 25 after the middle roller has stopped and/or reduced contact with the tissue. In other aspects, the coordinated operation of the proximal, middle and distal rollers 125 may be altered to vary the speed, timing of contact of each roller and/or overlapping tissue contact between rollers in any combination.

FIG. 19 illustrates a section view of a device for improving a fluid flow in a finger 60 through synchronized engagement of three rollers 125 with the finger 60. The tissue engaging zone 25 is found generally in the area of the ventral or palmar surface of the finger to engage the muscle or soft tissue targets in finger. Three rollers 125 are shown in the zone for engaging tissue 25. The distal roller is shown engaging tissue. The middle roller is shown with a tissue engaging surface 135 near the 4 o'clock position. The proximal roller is shown with a tissue engagement surface 135 near the 8 o'clock position. In one aspect, the tissue engaging zone 25 is selected to enhance roller 125 contact with the palmar surface of the fingers in which most of the veins of the fingers are located. This promotes maximum movement of fluid out of the finger. The zone to avoid in a finger based system is primarily based on patient comfort. As such, the rollers are adjusted and selected to make contact with the finger on the ventral surface, a.k.a. the palmar surface.

Operation of the device 100 in FIG. 18 would follow the earlier example of the coordinated roller 125 action described above in FIGs. 3A and 3B, and FIG. 17. FIG. 18 shows the distal most roller 125 in zone 25 engaging with tissue and producing the distal deflection 109a in the support surface 115 and related tissue, muscle and conduits in the finger 60. Continued operation of the device 100 will result in the middle roller 125 engaging tissue in zone 25 proximal to the tissue engaged by the distal roller. The middle roller will produce a corresponding deflection 109 associated with its movement. In one aspect, the middle roller 125 engages tissue in zone 25 after the distal most roller has stopped and/or reduced contact with the tissue. Continued operation of the device 100 will result in the proximal roller 125 engaging tissue in zone 25 proximal to the tissue engaged by the middle roller 125. The proximal roller will produce a corresponding deflection 109 associated with its movement. In one aspect, the proximal roller 125 engages tissue in zone 25 after the middle roller has stopped and/or reduced contact with the tissue. In other aspects, the coordinated operation of the proximal, middle and distal rollers 125 may be altered to vary the speed, timing between contact of each roller and/or overlapping tissue contact between rollers in any combination.

FIG. 20 illustrates a section view of a device for improving a fluid flow in an arm through synchronized engagement of three rollers with the arm. FIG. 20 illustrates a section view of a device for improving a fluid flow in the forearm 30 through synchronized engagement of three rollers 125 with the forearm 30. The tissue engaging zone 25 is described generally as the anterior aspect of the forearm between the elbow 36 and the wrist 34. The areas to avoid 20 include the elbow 36, the wrist 34 and the hand 32. In particular, the placement of the forearm 30 as shown in FIG. 20 is useful in adjusting the flow of fluid in conduits such as the veins and lymphatic channels of the forearm and the upper arm when placed properly in the device. Three rollers 125 are. shown in the zone for engaging tissue 25. The distal roller is shown engaging tissue. The middle roller is shown with a tissue engaging surface 135 near the 4 o'clock position. The proximal roller is shown with a tissue engagement surface 135 near the 8 o'clock position. In one aspect, the tissue engaging zone 25 is selected to enhance roller 125 contact with an area of the arm containing many veins and lymphatic channels. While the illustrated embodiment has three rollers, other embodiments may have one roller, two rollers or more than three rollers.

Operation of the device 100 in FIG. 18 would follow the earlier example of the coordinated roller 125 action described above in FIGs. 3A and 3B, FIG. 17, and FIG. 18. FIG. 19 shows the distal most roller 125 in zone 25 engaging with tissue and producing the distal deflection 109a in the support surface 115 and related tissue, muscle and conduits in the forearm 30. Continued operation of the device 100 will result in the middle roller 125 engaging tissue in zone 25 proximal to the tissue engaged by the distal roller. The middle roller will produce a corresponding deflection 109 associated with its movement. In one aspect, the middle roller 125 engages tissue in zone 25 after the distal most roller has stopped and/or reduced contact with the tissue. Continued operation of the device 100 will result in the proximal roller 125 engaging tissue in zone 25 proximal ^! to the tissue engaged by the middle roller 125. The proximal roller will produce a corresponding deflection ! " 109 associated with its movement. In one aspect, the proximal roller 125 engages tissue in zone 25 after the middle roller has stopped and/or reduced contact with the tissue. In other aspects, the coordinated operation of ' the proximal, middle and distal rollers 125 may be altered to vary the speed, timing between contact of each roller and/or overlapping tissue contact between rollers in any combination.

Embodiments of the present invention also relate to a method of moving fluid within a body. First, there is the step of positioning a body portion having a body conduit into a receptacle configured to receive the body portion so as to support the body portion at a first location and a second location. Examples of this step are illustrated in devices in contact with a body portion in the embodiments of FIGS. 3A, 3B, 18, 19 and 20. Moreover, several other embodiments are described as having proximal and distal supports 112, 114. In one aspect, after the positioning step, the distal portion of the body portion in the receptacle is elevated above the proximal portion of the body portion in the receptacle. An example of this configuration would result from positioning a leg in either the configurations of FIGs. 1A-1C or FIGS. 4A-4D. Alternatively, the proximal and distal ends may remain at about the same level as shown in FIGS. 3A, 3B and FIGS, 18, 19 and 20. In still other configurations, the proximal end may be higher than the distal end after performing the positioning step.

Next, there is the step of maintaining the axis of rotation of a roller 125 in a fixed position between the first location and the second location. Numerous embodiments illustrate how the axis of rotation of a roller 125 remains in a fixed position between a first location and a second location. FIGs. IA- 1C illustrate two rollers rotating about a fixed rotational axis between the ends of the housing 107, for example or the proximal and distal supports.

Next, there is the step of rotating the roller 125 about the axis of rotation to engage the body portion between the first location and the second location to move fluid from the body portion in the receptacle distal portion towards the body portion in the receptacle proximal portion. It is believed that the coordinated operation of the rollers as described above will provide synchronized contact between the roller and the engaged tissue to rhythmically provide pressure to a targeted conduit to move fluid in the body conduit. The coordinated movement of the roller engagement from the distal portion of the engagement zone 25 to the proximal portion of the engagement zone 25 is described above in at least the description of FIGS. 3A and 3B. Moreover, such coordinated roller engagement from distal to proximal portions of the engagement zone 25 is envisioned by FIGS. 18, 19 and 20. In a general sense, the operation of the devices may be altered to produce fluid flows towards or away from the heart. In another aspect, the operation of the device may result in increased flows towards or away from the thoracic cavity. In one aspect, the operation of the device and the related methods will increase the flow of fluid, such as blood, towards the heart. Specifically, in some embodiments the operation of the device produced increased venous blood flow and velocity towards the heart .

Next, there is the step of increasing the velocity of the fluid in the body conduit proximal to the receptacle proximal portion. It is believed that the coordinated distal to proximal engagement with the targeted tissue and increased fluid movement produces a corresponding increase in the velocity of the fluid in the body conduit proximal to the receptacle proximal portion. In support of this last point, Applicants have conducted testing that demonstrates that the coordinated operation rollers will produce increased fluid flow velocity in a body conduit. Applicants tested the performance of a two roller device embodiment similar in construction to the embodiment of FIG. IA. Six healthy- adult volunteers without leg trauma where placed in a supine position. The femoral vein resting velocity (cm/sec) was measured with a standard Doppler ultrasound (duplex) machine. Once the baseline velocity was established, each leg was placed on the device and the device started. Initial and steady state femoral vein velocity measurements were taken. This value represents an un-augmented or unassisted baseline velocity measurement.

The results of the prototype testing in this group showed that the prototype increased flow velocity in the femoral vein by at least 1.5 times the resting flow velocity. In addition, most subjects tested showed a flow velocity increase of between about three to six times the measured resting femoral velocity.

Numerous modifications and variations of the inventive method are possible. For example, in one aspect of the method of improving flow the positioning step, the maintaining step, the rotating step and the increasing step are performed without any portion of the receptacle encircling the body portion. A body portion is placed into and rests in an appropriate receptacle during use of the device. While an optional strap may be used to maintain the body portion in position during use, there is not any portion of the receptacle that encircles completely the body portion as found in the conventional sequential compression devices.

As made clear in the various devices described above, the methods of fluid improvement may be provided to a variety of body portions such as the legs, arms or fingers as well as a variety of body conduits. The body- conduit may be a vein. In one aspect, the body conduit proximal to the receptacle proximal- portion is one of a popliteal vein, a femoral vein or an iliac vein. The operation of the device may cause improved blood flow. The body conduit is not limited the circulatory system but may also be applied to a conduit within a portion of the lymphatic system. In this case, the fluid with improved flow is lymphatic fluid.

It is to be appreciated that during the rotating the roller step the body portion between the first location and the second location may include a wide variety of conduits and body portions. For example, the body portion may include the anterior aspect of the leg above the knee. The body portion may include an arm, a finger, a posterior portion of the leg below the knee including where the posterior portion of the leg excludes the Achilles tendon. Moreover, embodiments of the present invention may be designed and placed into operation in such as way as to avoid areas 20 that, for example, do not appreciably contribute to increased fluid flow or will result in roller contact with body structures that may lead to patient discomfort. In one example, the method of fluid flow is conducted by rotating the roller without contacting the Achilles tendon.

The above embodiments are merely illustrative of the various capabilities of the embodiments of the flow enhancement device of the present invention. It is to be appreciated that the embodiments described herein may be modified. Roller operations described herein may be altered to include a variety of roller shapes, sizes, operating speeds, pressure profiles, and manner of engaging with targeted tissue. Additionally or alternatively, the operation of the flow enhancement devices described herein may be modified to provide a wide array of roller synchronization schemes depending upon the needs, capabilities and physiology of a patient. One patient may have compliant conduits that will respond to lower roller engagement pressures while another patient may have less compliant conduits that may respond to higher roller engagement pressures and/or durations. Moreover, the synchronous operation of rollers may vary as to the timing between and overlap with the operation of another roller or with other rollers.

While many embodiments are described as having, in some cases, only a single roller at a time in contact within tissue in an engagement zone 25, the operation of embodiments of the device are not so limited. One roller or more than one roller may be in contact with tissue in a target zone 25. If more than one roller is in contact with the targeted tissue, the roller contact may be staged so that as the pressure produced by one roller decreases the tissue is met with an increasing pressure in a more proximal location within the targeted tissue zone. Accordingly, the operation of rollers and the contact of rollers with tissue and conduits within a target location may be changed to allow for over lapping roller/tissue contact, changes in the speed or frequency of roller contact as well as variations in roller created pressure exerted on a body conduit. II. Axis of Rotation Along the Blood Flow Path

FIG. 21 is an isometric view of an alternative embodiment of a device for improving flow. FIG. 22 is an exploded view of the device. FIG. 23 is an end view of the device.

In general, embodiments of the flow enhancement device include a bolster or support 1102, a roller assembly 1120 and a drive assembly 1146. The size, shape and interoperability of bolster, roller and drive are adapted and configured to support a portion of the body.

Within the supported body portion there is another portion that is engaged by the roller projection and, by interaction between the roller projection and the body portion, fluid flow within a lumen in the body portion is enhanced or improved. One example provided in the description that follows is the supported body portion is the leg and the portion engages by the roller projection is the area at the back of the calf. One measure of the improvement of fluid flow within a lumen is that the flow from the distal to proximal direction (generally in a direction towards the heart) increases. In one aspect, the velocity of fluid within the lumen after interaction with the roller projection is increased. The components of the device for improving flow will be described with reference to FIGS. 21, 22 and 23.

FIG. 21 is an isometric view of the device showing the bolster or support 1102 having a proximal end 1104 and a distal end 1106. A bolster 1102 has a support surface 1108 with an opening 1110. The surface 1108, proximal support 1104 and .the distal support 1102 each have a curved shape configured to receive a portion of a body to be treated by the device . The amount or degree of the shape can vary depending upon the body portion being treated. A cover 1116 (not shown in FIG. 21 but visible in FIG. 22) extends across opening 1110. An assembly of rollers 1120 (a pair is shown) is positioned beneath the opening 1110. Each roller 1120 has an outer surface 1128 with a projection 1132. The outer surface 1128 is shaped to conform to the profile of the body portion to engage with the roller projection 1132. The projection 1132 has a proximal end 1132a and a distal end 1132b that follows a projection along the length of the roller 1120. Each roller outer surface 1128 includes a neutral surface 1130. A neutral surface 1130 does not include the projection 1132. FIG. 23 is an end view of the device. The roller outer surface 1128, the projection proximal end 132a and the neutral surface 1130 are shown.

FIG. 21 also shows the shape of the opening 1110. The shape of the opening 1110 is used to help center or align the body portion with the rollers. The opening shape may have any of several different shapes depending upon a number of factors such as the size and shape of the body portion to be engaged with the rollers, the orientation of the body portion to the bolster among others. In the illustrated embodiment, the opening 1110 is shaped to support a portion of the upper calf and includes a lateral contour 1112 and a longitudinal contour 1114. The surface produced by the lateral and longitudinal contours (once covered by the cover 1116) produces a dish shape that mimics the shape of the calf. In this way, when a leg is placed on the bolster 1102 and the calf positioned near the opening 1110 (or on the cover 1116) there should be a natural dish formed that will cause the' calf to align into the desired placement relative to the rollers 1120. Additionally, the roller outer surface 1128 is also shaped to accommodate the targeted body portion. In the example where the calf is the target, the roller outer surface 1128 is shaped to engage with the calf and the neutral surface 1130 cooperates with the shape of ^" the opening 110 to provide a conforming shape to the calf profile or shape.

Also visible through the opening 1110 in the view of FIG. 21 is an incline 1144 that is used to adjust the relationship between the rotational axis of the rollers and longitudinal axis of the body portion supported on the bolster 1102.

FIG. 22 is an exploded view of the device for improving flow shown in FIGS. 21 and 23. The bolster 1102 has a proximal end 1104, a distal end 1106, a support surface 1108 and an opening 1110. As discussed above, the opening 1110 is sized to allow rollers 1120 to contact the targeted body portion that is otherwise supported by the bolster 1102. The opening 1110 is shaped to correspond to the roller contour and contact profile between the roller 1110 and the targeted body portion. In one aspect is the targeting contour is shaped to align the to targeted body portion to the rollers. The contour of the opening may be described as having a shape that is described by both a lateral contour 1112 and a longitudinal contour 1114. In one example, the lateral and longitudinal contours define a dish or bowl shaped to ensure alignment of the body portion and the rollers.

Also shown in FIG. 22 is the cover 1116. The cover 1116 is positioned across the opening 1110 to separate the roller 1120 from the body portion receiving therapy. The cover 1116 is fabricated from a material selected for patient comfort as well as to protect roller assembly from foreign objects. The cover 1116 could be formed from neoprene, polyester, nylon, rayon or other suitable natural or artificial material. The cover 1116 generally takes on the size and shape of the opening 110 as defined by the contours 1112, 1114.

The roller assembly 1120 includes the rollers 1122 positioned in the roller housing 1134 and supported by the incline 1144 on the base 1142. The incline 1144 provides orientation of the roller housing 1134/rollers 1120 for alignment with the body portion to receive therapy. In the illustrated embodiment each roller 1122 has a receiver 1124 to engage with the roller drive output 1158, 1160 and a shaft 1126 that extends though opening 126a in the housing 1134. The shaft 1126 is also support by a roller bearing 1136. A roller housing cover 1138 is positioned over the bearings 136 and a position sensor 140. The roller position sensor 1140 is positioned detect position of the roller 1122. In the illustrated embodiment, the position sensor 1140 is within the roller housing 1134 and placed to detect the position of the roller or the shaft 1126. The roller position sensor 1140 allows for the stop position of the roller 1122 to be controlled so that the rollers 1120 are in any desired position. For example, the position sensor 1140 may be used to detect whether the roller neutral position 1130 adjacent the body portion and, if not, provide feedback to the system controller so that the rollers continue to rotate until the neutral surface 1130 is in position adjacent the body portion. Any of a wide variety of conventional position detection methodologies such as, for example, optical, mechanical or electrical position detection may be used to identify roller position and provide a suitable feedback signal to a controller.

The drive assembly 1146 includes a motor 1148 with a drive shaft 1150 that is connected to the drive gear 1156 within the gear box housing 1152. The drive gear 1156 is coupled to roller drive gears and shafts 1158 that are coupled to and drive the rollers 1120. In the illustrated embodiment the conventional gears and internal workings of the drive gear 1156 and roller drivers 1158 are not shown but are within the various illustrated housings. The drive outputs 1160a, 1160b pass though the gearbox housing 1152 and engage with the roller receivers 1124 of the rollers 1120. In the illustrated embodiment, the motor 1148 sits within and is supported by roller housing 1134. The gearbox housing 1152 is attached to the roller housing 1134. Operation of the motor 150 produces rotation of the rollers 1120.

The drive assembly may be configured to operate the rollers in any of a number of different ways. For example, the gearing of the drive train may be selected so that the rollers rotate at the same speed, a slower speed or a faster speed than the rotational speed of the motor drive shaft 1150. In another example, the gearing of the drive train may be selected such that the rollers both rotate in the same or different direction as the rotation of the motor drive shaft 1150. For example, both rollers may rotate in a clockwise direction, counterclockwise direction and those directions may be the same as or different than the rotation direction of the motor drive shaft 1150. In another embodiment, the drive train may provide for clockwise rotation of one roller and counter-clockwise rotation of the other roller.

FIG. 24 is a frontal view of a roller with a projection along the roller outer surface. The roller 120 has a rotational axis 1170. The roller 1120 may be configured in any of a number of ways for rotation about the rotational axis 1170. A single shaft may extend through the entire length of the roller. Alternatively, a portion of a shaft segment may be inserted into each end of the roller with one segment to engage with the drive train and the other with a support. Still another alternative is one illustrated in FIG. 22 where a receiver 1124 engages with a drive output 1160a, 1160b and a shaft 1126 is supported by a bearing 1136. The roller is supported and driven in any conventional manner to allow engagement with the target body portion.

The physical characteristics of the roller 1120 are selected depending upon the portion of the body selected to receive therapy. The roller length "L" selected based on longitudinal dimension of the body portion to receive therapy. In one example, the length of the roller corresponds to the longitudinal length of the calf or a portion of the calf.

The roller outer surface 1128 is also selected to both correspond to and ensure engagement with the targeted body portion. The outer surface 128 includes a neutral surface portion 1130. The neutral surface portion describes the general shape of the roller outer surface from the roller proximal to the roller distal end. In one aspect, the roller outer surface defines a contour that matches body portion to receive therapy. The contour or outer roller shape could be decreasing diameter then increasing diameter to provide a hourglass shape . The hourglass shape may conform to the contour of the calf. The outer surface 128 may have other shapes depending on body type to receive therapy.

The roller outer surface also contains a projection 1132. The projection 1132 is a raised contour above the roller outer surface 1128. The profile of the projection 1132 may include a regular geometric shape such as the semicircular shape shown in FIG. 24. Other projection shapes are possible including other smooth arcurate shapes, curvilinear or other rounded shapes. The projection shape may be constant or variable along the trajectory. The projection shape may be smooth or include surface undulations. In still other embodiments, the outer surface of the projection 1132 may include surface texturing or other features.

The projection 1132 has a proximal end 1132a and a distal end 1132b and moves along a trajectory along the circumference of the roller from the proximal end to the distal end of the outer surface 1128. The trajectory may follow any of a number of paths along the roller. For example, the trajectory may be spiral path with a fixed pitch or a spiral path with a variable pitch. The proximal and distal ends 1132a, 1132b may have a tapered shape that provides a transition from the projection shape to the neutral roller surface 1130. In one embodiment, the trajectory forms a path where the projection proximal and distal ends 1132a, 1132b circumscribe less than a complete circumference of the roller 1120. In addition, the gap between the projection proximal and distal ends 1132a, 1132b comprises the neutral surface portion 1130. FIGS. 25A-25D are a top down view of the device for improving flow of FIG. 21 showing the rotation of the rollers and the resulting movement of the projection 1132. In this illustrative embodiment, the left roller is driven to rotate in a counter-clockwise direction and the right roller is driven to rotate in a clockwise direction as indicated by the arrows. In all of the embodiments of FIGS. 25A-25D the cover 1116 is removed so that the rollers are seen in the opening 110.

FIG. 25A illustrates the rollers in a position where the engaged tissue would contact or be supported by the roller neutral surface 1130. After some rotation of the rollers into the position shown in FIG. 25B, a portion of the projection 1132 near the distal end 1132b is in position to contact the body portion supported by bolster 1102 and positioned to receive therapy. FIG. 25C illustrates continued rotation of the rollers 120 so that a portion of the projection 1132 between the proximal and distal ends 1132a, 1132b would be in contact with the target body portion. FIG. 25D illustrates continued rotation of the rollers so that a portion of the projection 1138 near the proximal end 1132a would be in contact with the target body portion. Continued rotation of the rollers would place the rollers into the position shown in FIG. 25A. In the roller operation illustrated in the FIGS. 25A-25D sequence, the roller and target tissue engagement would follow a neutral position (i.e., no projection contact with tissue) and a series of projection contact positions that would travel on the tissue in a distal to proximal fashion depending upon the projection trajectory. In the illustrated embodiment of FIGS. 25A-25D, rotation of the rollers produce a synchronized, dual traveling contact points that move in a distal to proximal direction.

FIG. 26 is a section view of the device for improving flow of FIG. 21 with a leg positioned to receive therapy from the rollers in a target area. In the illustrated embodiment, the target area to receive therapy is a portion of the calf.

The drive assembly 1146 may be powered by batteries or be plugged into an electrical outlet. A control system is also provided to operate the drive assembly 1146 in accordance with inputs from a user via user controls. The user controls would allow the user to turn the device on, off, adjust the roller speed or select a roller speed from one of several pre-set roller speeds. The control system may also receive inputs in order to control the movement of the rollers. In addition to the user inputs described above, the control system may also receive a signal from the roller position sensor 1140. One use of the signal from the roller position sensor 1140 includes maneuvering a roller so that the neutral position area 1130 is oriented towards the engaged body portion with the roller is commanded to "stop." As such, once the "stop" command is provided to the control system, the drive assembly would operate to rotate the rollers until the neutral position 1130 is oriented towards the engaged tissue. In other words, the roller is rotated until the projection 1132 no longer engages with the target tissue.