Medical drain bulb apparatuses

Abstract

Medical drain bulbs and systems for draining fluid from a body tissue or cavity. A drain, which may be configured for placement within a patient's body, may include a tube and may be fluidly coupled with a bulb. Squeezing the bulb may create a negative pressure sufficient to draw fluid from the patient's body into the bulb via the drain and the tube. The systems may include features that provide draining efficiency and convenience of use. In some examples, a valve assembly may allow multiple drains to be coupled with a single bulb. In some examples, the system may include a port that allows a flushing fluid to be injected into the drain to flush a tissue space around the drain.

Description

MEDICAL DRAIN BULB APPARATUSESCLAIM OF PRIORITY

[0001] This patent application claims priority to U.S. provisional patent application no. 63 / 733,996, titled “MEDICAL DRAIN BULB APPARATUSES” and filed on December 13, 2024, herein incorporated by reference in its entirety.INCORPORATION BY REFERENCE

[0002] All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.BACKGROUND

[0003] Drain systems are positioned underneath the skin and in the internal body cavity during many surgical procedures for draining the surgical site during post-operative healing. These drains are connected to tubing that crosses the skin, allowing fluid and tissue exudate to drain freely away from the internal surgical wound. Drains often remain in position from a couple of days to several weeks. The drain can facilitate the healing process in a number of ways, for example, by reducing seromas (localized accumulation of serous fluid) in the region of the surgical wound; by removing body fluids, blood, pus, and necrotic material, all of which are potential growth medium for microorganisms that could lead to infection; by increasing the flow of fluid and nutrients from healthy tissue to the surgically wounded tissues; by reducing pressure in the area that could inhibit free-flowing of nutrients and removal of waste products; and by improving apposition (contact) between cut or separated layers of tissue, decreasing sliding motion between these surfaces. In general, the goal is for these layers of tissue to reconnect or adhere to each other during the healing process.

[0004] To increase the healing benefit of a drain, and encourage one-way movement of fluid (in-to-out), negative pressure may be applied to the external end of the drain tube. The negative pressure increases the flow of fluid and nutrients from healthy tissue to the surgically wounded tissues, and outward, carrying waste products and other infective elements away from the body. Within the operating room or other clinical settings, electronically powered pumps may be used to apply negative pressure to the drain tubing. For ambulatory or at-home stages of healing, electronic or complex mechanical systems are sometimes used to apply negative pressure to a drain. However, these technologies are limited by either requiring a hospital setting, are high cost, or both.- 1 -SG Docket No.: 14450-716.600

[0005] A simpler and less expensive alternative to electronic pump systems is manual drain bulbs, which include a flexible bulb that may be squeezable by hand. The patient periodically squeezes the bulb to create suction that pulls fluid from the wound site into the bulb, which the patient then empties. One of the problems with conventional bulb drains is that the magnitude of the negative pressure drops quickly as fluid enters the bulb, thereby reducing its ability to drain fluid. Another problem with conventional bulb drains is that the system requires that the patient have some privacy and be near a sink or toilet to empty the bulb. An additional problem with conventional bulb drains is that some situations require the patient to manage multiple bulbs for draining multiple drainage sites. These factors can reduce the effectiveness of bulb drains and / or reduce patient compliance with using drain bulbs. It would be helpful to have bulb drains and drain systems that are simple, efficient at draining fluid, convenient to use, and cost effective.SUMMARY OF THE DISCLOSURE

[0006] Described herein are medical drain bulb apparatuses (e.g., devices, systems, assemblies and / or subassemblies). The apparatuses are configured to efficiently drain fluid from one or more tissue sites, thereby improving drainage of the tissue site compared to conventional drain bulbs. The apparatuses described herein include features that make using the apparatuses more convenient compared to conventional drain bulbs. For example, the apparatuses may include features that allow drainage from multiple tissue sites using a single bulb. The apparatuses described herein include features that allow for fluid flushing of a tissue site, for example, to remove material such as blood clots and fibrous material from the tissue site.

[0007] According to one example, a medical drain system includes a drain assembly, a bulb and a valve assembly. The drain assembly includes: a first drain having a first tube; and a second drain having a second tube, where each of the first and second drains is configured to be positioned within a patient’s body, and where each of the first and second tubes is manually compressible. The bulb is fluidly coupled with the first and second tubes. The bulb is configured to generate a negative pressure within the first and second tubes and the bulb upon manual compression of the bulb. The bulb is configured to generate sufficient negative pressure to draw fluid from the patient’s body into the bulb via each of the first and second drains positioned within the patient’s body. The valve assembly is configured to control fluid flow between each of the first and second tubes and the bulb. The valve assembly is configured to: maintain the negative pressure within the first and second tubes and the bulb upon movement of a pinching force applied along one or both of the first and second tubes; and limit or prevent fluid from backflowing out of the bulb into the first or second tubes. The valve assembly may include a first one-way valve and a second one-way valve, wherein the first one-way valve is configured to- 2 -SG Docket No.: 14450-716.600provide one-way fluid flow from the first drain to the bulb, and wherein the second one-way valve is configured to provide one-way fluid flow from the second drain to the bulb. The valve assembly may include: a first on-off valve that is configured to open and close fluid connection between the bulb and the first drain; a second on-off valve that is configured to open and close fluid connection between the bulb and the second drain; and a one-way valve configured to limit or prevent fluid from flowing out of the bulb and into the first or second tubes. In some examples, the valve assembly further may include a y-connector that fluidly couples the first and second tubes to the bulb. The first and second drains may be configured to be placed within different tissue site locations within the patient’s body. The medical drain system may include one or more additional drains, other than the first and second drains, that is / are fluidly coupled with the bulb. The medical drain system may further include a fluid collection bag that is arranged to collect fluid from the bulb. The bulb may include a first opening that provides a fluid access between the bulb and each of the first and second tubes, wherein the bulb further includes a second opening that provides fluid access between the bulb and the fluid collection bag. The medical drain system may include a one-way valve that is configured to limit or prevent fluid backflow from the fluid collection bag into the bulb. At least one of the first and second drains may include multiple holes for efficiently collecting fluid from the patient’ s body. The bulb may include a spring force modulator that is configured to modulate a spring force provided the bulb, wherein the spring force modulator includes one or more protrusions that protrude from an inner surface of the bulb, the spring force modulator configured to limit an extent to which the bulb collapses inward upon application of the manual compression, thereby causing the bulb to maintain the negative pressure within a predetermined range as the bulb returns to an expanded state.

[0008] According to another example, a method of using medical drain system having a first drain including a first tube fluidly coupled with a bulb, and a second drain including a second tube fluidly coupled with the bulb, includes: positioning the first and second drains within a patient’s body; manually compressing the bulb; and dislodging material within at least one of the first and second tubes. Manually compressing the bulb generates a negative pressure within the first and second tubes and the bulb, where the negative pressure draws fluid from the patient’s body into the bulb via each of the first and second drains positioned within the patient’s body. Dislodging material within at least one of the first and second tubes is done by moving a pinching force applied along the at least one of the first and second tubes in a direction toward the bulb. The negative pressure within the first and second tubes and the bulb is maintained while applying and moving the pinching force. One or more one-way valves may limit or prevent fluid from backflowing out the bulb and into the at least one of the first and second - 3 -SG Docket No.: 14450-716.600tubes. The medical drain system may include a first one-way valve and a second one-way valve, where the first one-way valve provides one-way fluid flow from the first drain to the bulb, and wherein the second one-way valve provides one-way fluid flow from the second drain to the bulb. The method may further include adjusting a valve assembly to close fluid connection between the first tube and the bulb prior to applying and moving the pinching force on the second tube, and / or to close fluid connection between the second tube and the bulb prior to applying and moving the pinching force on the first tube. Positioning the first and second drains may include positioning the first and second drains at different tissue site locations within the patient’ s body. The method may further include draining fluid from the bulb into a fluid collection bag that is fluidly coupled to the bulb via a collection bag tube. At least one of the first and second drains may include multiple holes for efficiently collecting fluid from the patient’ s body. The bulb may include a spring force modulator including one or more protrusions that protrude from an inner surface of the bulb and that limits an extent to which the bulb collapses inward upon manual compression of the bulb, thereby causing the bulb to maintain the negative pressure within a predetermined range as the bulb returns to an expanded state.

[0009] According to a further example, a medical drain system includes: a drain, a bulb, a port and a valve assembly. The drain is configured to be positioned within a patient’s body. The drain includes a tube. The bulb that is in fluid communication with the tube. The bulb is configured to generate suction within the tube and the bulb upon manual compression of the bulb. The bulb is configured to generate sufficient suction to draw fluid from the patient’s body into the bulb via the drain when positioned within the patient’s body. The port provides fluid access to the tube. The port is configured to allow application of a positive flushing fluid pressure and / or a negative pressure through the tube toward the drain within the patient’s body. The valve assembly is configured to switch fluid access to the drain between the bulb and the port. The valve assembly may include a first on-off valve that is configured to open and close fluid access to the drain from the port, and a second on-off valve that is configured to open and close fluid access to the drain from the bulb. The valve assembly may include a switching valve that is configured to switch fluid access to the drain between the bulb and the port. The valve assembly may be arranged close to the patient’s skin to minimize to reduce a chance of inflammatory or infective material entering a tissue space around the drain. The port may be configured to allow flushing fluid to be injected into the tube toward the drain within the patient’s body. The port may be configured to be connected to a vacuum source to apply suction within the tube and the drain within the patient’ s body. The medical drain system may include multiple drains having corresponding multiple tubes, where the multiple drains are fluidly coupled with the bulb, and where the valve assembly is further configured to: maintain the- 4 -SG Docket No.: 14450-716.600suction within the multiple tubes and the bulb upon movement of a pinching force applied along one or more of multiple tubes; and limit or prevent fluid from backflowing out of the bulb into the multiple tubes. The bulb may include a spring force modulator including one or more protrusions that protrude from an inner surface of the bulb and that limits an extent to which the bulb collapses inward upon manual compression of the bulb, thereby causing the bulb to maintain the suction within a predetermined range as the bulb returns to an expanded state.

[0010] According to an additional example, a method of using a surgical drain system that has a drain including a tube that is fluidly coupled with a bulb, includes: positioning the drain within a patient’s body; adjusting a valve assembly that is configured to switch fluid access to the drain between the bulb and a port that is coupled to the tube, where adjusting the valve assembly comprises opening fluid access from the port to the drain and closing fluid access from the bulb to the drain; injecting a flushing fluid through the port to flush a tissue space around the drain; adjusting the valve assembly to open fluid access from the bulb to the drain and closing fluid access from the port to the drain; and drawing fluid from the drain in the patient’s body into the bulb. The method may further include applying negative pressure through the port to apply suction to the tissue space around the drain. The method of may further include cycling between injecting the flushing fluid in the port and applying the negative pressure through the port to cycle a positive fluid pressure and the negative pressure to the tissue space around the drain. The method may further include manually compressing the bulb to generate a suction within the tube and the bulb, wherein the suction draws the fluid from the patient’s body into the bulb when the valve assembly opens fluid access from the bulb to the drain and closes fluid access from the port to the drain. The bulb may include a spring force modulator including one or more protrusions that protrude from an inner surface of the bulb and that limits an extent to which the bulb collapses inward upon manual compression of the bulb, thereby causing the bulb to maintain the suction within a predetermined range as the bulb returns to an expanded state. Adjusting the valve assembly to open fluid access from the port to the drain and close fluid access from the bulb to the drain may include: opening a first on-off valve to open fluid access from the port to the drain; and closing a second on-off valve to close fluid access from the bulb to the drain. Adjusting the valve assembly to open fluid access from the port to the drain and close fluid access from the bulb to the drain may include adjusting a switching valve to open fluid access from the port to the drain and to close fluid access from the bulb to the drain. The method may further include arranging a position of the valve assembly close to the patient’s skin to minimize to reduce a chance of inflammatory or infective material entering the tissue space around the drain. The medical drain system may include multiple drains having corresponding multiple tubes, where the multiple drains are fluidly coupled with the bulb, wherein the method- 5 -SG Docket No.: 14450-716.600further comprising dislodging material within at least one of the multiple tubes by moving a pinching force applied along the at least one of the multiple tubes in a direction toward the bulb, where a suction within at least one of the multiple tubes and the bulb is maintained while applying and moving the pinching force. One or more one-way valves may limit or prevent fluid from backflowing out the bulb and into the tube.

[0011] Generally, the drain bulbs described herein may have a flexibility, size, and shape suitable for being held and squeezed by a person’s hand. The bulbs may have a volume capacity suitable for being at least partially filled with each squeeze of the person’s hand. The bulbs may be made of an elastic material, such as one or more polymers (e.g., one or more of silicone, polyvinyl chloride (PVC), neoprene, ethylene propylene diene monomer (EPDM), polyurethane, silicone-polyurethane copolymers, rubber, thermoplastic elastomers, and / or other elastomers). The bulbs may be opaque, or may be transparent and / or translucent and may have external markings or gradations in order for the user to be able to visualize and determine (measure or approximate) the amount of fluid collecting / passing through the bulb.

[0012] The drain bulbs described herein may be configured to more efficiently drain fluid from a tissue site with each pump cycle compared to conventional drain bulbs. The improved efficiency and convenience of the drain bulbs and systems may result in improved patient compliance and better wound care compared to conventional pumps and systems.

[0013] For example, the drain bulbs may include one or more protrusions that protrude from an inner surface of the bulb and that modulate the spring force of the bulb. The one or more protrusions may comprise one or more internal ribs around an inner circumference of the bulb. The one or more internal ribs may be arranged along a minor axis of the bulb. The one or more protrusions may comprise multiple internal ribs around the inner circumference of the bulb. In any of these examples, the one or more protrusions may comprise one or more struts within the inner chamber that connects a first side of the inner surface of the one or more walls to a second side of the inner surface of the one or more walls. The one or more protrusions may provide one or more regions of increased thickness of the one or more walls. The spring force modulator may further comprise one or more outer protrusions that protrude from an outer surface of the one or more walls.

[0014] In general, the drain bulbs may be configured to maintain a negative force within a predetermined range. In some cases, the predetermined range may be between about -50 mmHg to -125 mmHg. The spring force modulator may be configured to maintain the negative pressure within the predetermined range until at least 30% of a volume of the inner chamber is filled with fluid. The one or more walls of the bulb are made of a polymer material comprising one or more- 6 -SG Docket No.: 14450-716.600of silicone, polyvinyl chloride (PVC), neoprene, ethylene propylene diene monomer (EPDM), polyurethane, a silicone-polyurethane copolymer, rubber, and a thermoplastic elastomer.

[0015] In some examples, the drain systems may include a fluid collection bag that is detachable from the drain bulb, thereby providing convenience for the user. The drain systems may include a valve system that prevents backflow into the tissue site and / or fluid collection bag, thereby reducing the incidence of contamination.

[0016] Any of these apparatuses may include a tube coupled to the bulb such that an inner lumen of the tube is fluidically coupled to the inner chamber via the opening of the bulb. In general, the bulb may have a wall thickness (outside of the spring force modulator region) of between 1 mm and 6 mm. The one or more protrusions of the spring force modulator may have a thickness of between about 1.2 mm and about 10 mm. The inner chamber may have a volume of between 50 milliliters (mL) and 600 mL.

[0017] These and other examples and features are described herein.

[0018] All of the methods and apparatuses described herein, in any combination, are herein contemplated and can be used to achieve the benefits as described herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] A better understanding of the features and advantages of the methods and apparatuses described herein will be obtained by reference to the following detailed description that sets forth illustrative embodiments, and the accompanying drawings of which:

[0020] FIG. 1A illustrates an example surgical drain bulb system.

[0021] FIG. IB illustrates an example bulb with tube and stopper.

[0022] FIG. 1C illustrates an example use of a bulb for pumping fluid.

[0023] FIGS. 2 A illustrates front and perspective section views of an example standard bulb; and FIG. 2B illustrates a graph showing a negative pressure profile of the bulb of FIG. 2 A.

[0024] FIG. 3A illustrates front and perspective section views of an example bulb having a thick wall, an elongated length, and an inner protruding feature; and FIG. 3B illustrates a graph showing a negative pressure profile of the bulb of FIG. 3A.

[0025] FIG. 4A illustrates front and perspective section views of an example bulb having a thick wall; and FIG. 4B illustrates a graph showing a negative pressure profile of the bulb of FIG. 4A.

[0026] FIG. 5A illustrates front and perspective section views of an example bulb having an elongated length; and FIG. 5B illustrates a graph showing a negative pressure profile of the bulb of FIG. 5A.- 7 -SG Docket No.: 14450-716.600

[0027] FIG. 6A illustrates front and perspective section views of an example bulb having an outer protruding feature; and FIG. 6B illustrates a graph showing a negative pressure profile of the bulb of FIG. 6A.

[0028] FIG. 7A illustrates front and perspective section views of an example bulb having an inner protruding feature; and FIG. 7B illustrates a graph showing a negative pressure profile of the bulb of FIG. 7A.

[0029] FIGS. 8A-8C illustrate perspective and front views of the bulb of FIG. 2A being compressed.

[0030] FIGS. 9A-9C illustrate perspective and front views of the bulb of FIG. 3 A being compressed.

[0031] FIG. 10A illustrates front and perspective section views of an example bulb having an elongated length and an inner protruding feature; and FIG. 10B illustrates a graph showing a negative pressure profile of the bulb of FIG. 10A.

[0032] FIGS. 11A-11G illustrate front and perspective section views of example bulbs having various types of spring force modulators.

[0033] FIG. 12 schematically illustrates an example drain pump system.

[0034] FIG. 13 is a graph illustrating a negative pressure profile for one example of a drain pump system actuated multiple times, showing that the negative pressure may fall outside of an optimal negative pressure range during the repeated actuation.

[0035] FIG. 14 is a graph illustrating the negative pressure profile of an example of a drain pump system configured to maintain the negative pressure within an optimal negative pressure range over repeated actuation of the drain pump bulb.

[0036] FIG. 15A illustrates an example of a bulb system as described herein.

[0037] FIG. 15B shows an example of a graph showing negative pressure vs. total fluid collected in one example of a system (such as the system shown in FIG. 15A).

[0038] FIG. 16 schematically illustrates an example of a system including a bulb and collection bag assembly.

[0039] FIG. 17 shows an example of a system including a bulb and collection bag assembly.

[0040] FIG. 18 illustrates an example apparatus that has a multiple drain configuration and that is configured for the active management by a user to provide retrograde pressure / flow protection.

[0041] FIG. 19 illustrates an example apparatus that has a multiple drain configuration and that is configured to provide passive retrograde pressure / flow protection.

[0042] FIGS. 20A-20C illustrate an example apparatus that includes drain flushing features.- 8 -SG Docket No.: 14450-716.600

[0043] FIG. 21 illustrates an example apparatus that includes alternative drain flushing features.DETAILED DESCRIPTION

[0044] Described herein are surgical drains and systems for removing fluid (e.g., exudate, leukocytes, blood, and / or pus) from a soft tissue site, such as a wound, body cavity, and / or organ. The drains include one or more bulb pumps that are fluidly coupled to the target tissue site. The bulb pump(s) are configured to efficiently apply suction to pull fluid away from the target tissue site by negative pressure created by squeezing the bulb.

[0045] The drains and systems described herein may be designed to improve patient compliance with post-surgical procedures. Patient compliance refers to the ability of the patient to perform the necessary tasks involved in self-care, in this case, while the drain is in-situ. Management of the drainage system requires conscientious effort, which can be difficult for users. The quality of care can vary, depending on the degree of attention and timely emptying of the bulb. The devices and systems described herein can increase the pumping efficiency of bulb pumps and make the drain pumps more convenient to use, thereby improving patient compliance and wound healing outcomes.

[0046] The drain pumps and systems described herein may be used to remove fluid from tissue in any of a number of medical situations. Generally, the drain pumps and systems may be used to remove fluid from tissue to promote tissue healing and / or prevent or reduce the occurrence of infection. In some cases, the drain pumps and systems may be used to remove fluid (e.g., exudate) from a tissue site after a surgical procedure, such as hernia repair surgery, breast surgery, plastic reconstruction surgery, orthopedic surgery, or other procedures in need of post-surgical drainage. In some cases, the drain pumps and systems may be used during a surgical procedure. In some cases, the drain pumps and systems may be used to drain fluid from tissue that has experienced non-surgical trauma or injury.

[0047] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein and may be used to achieve the benefits described herein.

[0048] FIGS. 1A-1C show an example surgical drain bulb system for draining fluid from a patient’s soft tissue. In the example of FIG. 1A, the system includes four bulbs 103, which are each connected to a distal end of a flexible drain tube 101. Other systems may include fewer (e.g., 1, 2 or 3) bulbs or more (e.g., 5, 6, 7, 8, or more) bulbs. The bulb 103 defines an inner chamber / cavity that is configured to hold fluid drained from the patient’s tissue. The walls of the- 9 -SG Docket No.: 14450-716.600bulb 103 may be flexible enough to collapse when squeezed by the patient’s hand. The size of the bulb 103 may vary. In some cases, the bulb 103 has a shape and size suitable for being held in and / or squeezed by a person’s hand.

[0049] Referring to FIG. IB, the distal end of the tube 101 is fluidly coupled to a first opening 104 of the bulb 103 to provide fluid access to the internal chamber of the bulb 103. A proximal end of the drain tube 101 is configured to be in fluid communication with the target tissue site, for example, via a tissue drain 107. The tissue drain 107 may include multiple holes for collecting fluid across a greater area (e.g., at the target tissue site). If multiple bulbs 103 are used, the tissue drains 107 of the corresponding drain tubes 101 may be positioned at different locations at the target tissue site to provide drainage to different regions of the tissue.

[0050] In the examples shown in FIGS. 1A-1C, the bulb 103 includes a stopper 105 that is configured to open and close a second opening 106 of the bulb 103 that provides access to the internal chamber of the bulb 103. When closed, the stopper 105 blocks the second opening and access to the internal chamber of the bulb 103. The stopper 105 may include a removable cap that is configured to be removed to open the second opening 106 and replaced to close the second opening 106. In other examples, the second opening 106 of the bulb 103 may be open and closed using one or more different mechanisms, such as one or more valves, plugs and / or connectors.

[0051] The second opening 106 may act as an air vent to control the flow of air in and out of the bulb 103. For example, as shown in FIG. 1C, the bulb 103 may be primed by squeezing the bulb 103 while the stopper 105 is open to remove at least some air from the internal chamber of the bulb 103 via the second opening 106. Then, the stopper 105 is closed to create a negative pressure within the internal chamber of the bulb 103 that draws fluid (via the first opening 104 and the drain tube 101) into the bulb 103 as the walls of the bulb 103 spring outward until the bulb 103 returns to its original (before squeezed) shape. To empty the bulb 103, the stopper 105 is removed, the bulb 103 is tilted so the second opening 106 is facing downward, and the bulb 103 is squeezed to force fluid to exit from the bulb 103 via the second opening 106 (e.g., into a cup for measurement as shown in FIG. 1A). After emptying, the stopper 105 may be closed again to close access to the internal chamber of the bulb 103 until the patient (or caregiver) is ready to pump more fluid from the tissue site.

[0052] One of the problems with conventional bulb pumps is that the negative pressure created by the outward springing of the bulb walls drops quickly as fluid enters the internal chamber. To illustrate, FIGS. 2 A and 2B show example section views and a negative pressure graph, respectively, for a bulb 203. As shown in FIG. 2A, the bulb 203 has an oblong (e.g., ellipsoid) shape having a length Li as measured along the major axis. Walls 209 of the bulb 203 - 10 -SG Docket No.: 14450-716.600define an inner chamber 211 that has a volume capacity of 100 mL. The bulb 203 may be made of a polymer material, such as silicone. In this example, the bulb 203 includes a first opening 204 and a second opening 206 that each provides access to the inner chamber 211. The first opening 204 may be configured to provide access to a drain tube (e.g., tube 101) that provides fluid access to a tissue drain (e.g., tissue drain 107). The second opening 206 may be arranged to act as an air vent and / or fluid outlet for draining the bulb 203. The walls 209 are flexible enough to be compressed inward (toward the inner chamber 211) by hand in a direction along the minor axis X of the bulb 203. In this case, the walls 209 have a thickness Ti (e.g., about 1.7 mm to about 4.2 mm) and are uniformly thick along the sides the bulb 203.

[0053] The graph of FIG. 2B shows a negative pressure profile created by the bulb 203 (e.g., amount of fluid collected with respect to the pressure within the bulb). The graph shows a measured magnitude of negative pressure (y-axis) as a function of a volume of fluid (x-axis) collected in the bulb 203 as the walls 209 spring (apply a spring force) outward and the bulb 203 returns to its original (e.g., ellipsoid) shape. The horizonal dashed line indicates the highest desired magnitude of negative pressure (Pi). In some cases, Pi is based on an industry determined clinical standard, which in some cases is -125 mmHg. The vertical dashed line indicates the maximum internal chamber volume (Vi) of the bulb 203. In this example, Vi for the bulb 203 is 100 mL. The optimal negative pressure range (OPR) indicates a clinically optimal negative pressure range for efficient and safe collection of fluid, which in some cases may be from about -80 and -125 mmHg. As shown, the negative pressure drops dramatically below the optimal negative pressure range OPR soon after fluid enters the bulb 203. For example, there is a large pressure drop (indicated by the downward arrow) by the time about 25 milliliters (mL) of fluid is collected in the bulb 203. In addition, the negative pressure is below the optimal negative pressure range OPR for most of the pump cycle (i.e., one squeeze of the bulb 203). This means that the pumping ability of the bulb 203 drops dramatically as soon as it begins to fill with fluid, thereby making the bulb 203 very inefficient at pulling fluid from the tissue site with every pump.

[0054] The poor performance of a bulb 203 such as the bulb in FIG. 2A may affect patient compliance of using the bulb 203. For example, if the bulb 203 fills past 30%, or completely fills (which is often the case), then the bulb 203 is only capable of creating a very low negative pressure. The extra effort to empty and recharge the bulb may discourage the patient from doing so. Described herein are spring force modulating features that can increase the pump efficiency of a bulb, thereby improving patient compliance and quality of care. The bulb(s) shown in FIGS. 1A-1C and 2 may include one or more features that desirably modulate the spring force, as illustrated and described below.- 11 -SG Docket No.: 14450-716.600

[0055] For example, FGS. 3A and 3B show example section views and a negative pressure graph, respectively, for an example bulb 303 having spring force modulating features for improving pumping efficiency. The bulb 303 may be made of the same material as the bulb 203 in FIG. 2A. Similar to the bulb 203, bulb 303 includes walls 309 that define an inner chamber 311 that has a fluid volume capacity of 100 mL. A first opening 304 and a second opening 306 of the bulb 303 each provide access to the inner chamber 311. The first opening 304 may be configured to provide access to a drain tube (e.g., tube 101) that provides fluid access to a tissue drain (e.g., tissue drain 107). The second opening 306 may be arranged to act as an air vent and / or fluid outlet for draining the bulb 303. The walls 309 are flexible enough to be compressed inward (toward the inner chamber 311) by hand in a direction along the minor axis X of the bulb 303.

[0056] Compared to the bulb 203 of FIG. 2A, the bulb 303 includes features that modulate the spring force created by the walls 309. For example, the bulb 303 has walls 309 having a greater thickness T2 (e.g., about 1.8 mm to about 6.0 mm) compared to the thickness Ti of the walls 209 of bulb 203. In some cases, the thickness T2 may be at least 1.1 (e.g., 1.1, 1.2, 1.3, 1.4,1.5, 1.6, 1.8, 2.0, 2.2, 2.5, 2.8, 3.0, 3.5, 4.0 or more) times greater than the thickness Ti of the walls 209 of bulb 203. In addition, the walls 309 include a localized region 308 of greater thickness. In this case, the localized region 308 of greater thickness is in the form of a protrusion that protrudes from an inner surface of the walls 309 within the inner chamber 311. The protrusion is in the shape of a rib around an inner circumference of the bulb 303 (in this case, along the minor axis X of the bulb 303). Further, the bulb 303 has a length L2 that is greater than the length Li of bulb 203. In some cases, the length L2 may be at least 1.1 (e.g., 1.2, 1.3, 1.4, 1.5,1.6, 2.0 or more) times greater than the length Li.

[0057] The graph of FIG. 3B shows a measured magnitude of negative pressure (y-axis) as a function of a volume of fluid (x-axis) collected in the bulb 303 as the walls 309 spring outward and the bulb 303 returns to its original (e.g., ellipsoid) shape. This graph illustrates that the negative pressure is maintained within the optimal negative pressure range OPR (e.g., between about -80 and -125 mmHg) as fluid enters the bulb 303 and until the bulb 303 reaches the maximum internal chamber volume (Vi). This means that the bulb 303 is able to efficiently pull fluid from the tissue site with every pump. In addition, the bulb 303 is able to maintain some negative pressure (above zero) past the maximum volume Vi of fluid collected p.

[0058] In any of the apparatuses and methods described herein the bulb may be configured to expand back outwards, resulting in a sustained negative pressure within the desired target range (e.g., the optimal pressure range) over time, wherein the time that the bulb is expanding and applying the force may be between, e.g., about 1 minute and about 30 minutes or more, between - 12 -SG Docket No.: 14450-716.600about 30 seconds and about 30 minutes or more, between about 1 minute and 25 minutes or more, between about 1 minutes and 20 minutes or more, between about 1 minute and 15 minutes or more, between about 1 minute and 10 minutes or more, between about 1 minute and 8 minutes or more, between about 1 minute and 5 minutes or more, 30 seconds or more, 1 minute or more, 2 minutes or more, 3 minutes or more, 4 minutes or more, 5 minutes or more, 6 minutes or more. 7 minutes or more, 8 minutes or more, 9 minutes or more, 10 minutes or more, etc.). The methods and apparatuses described herein may be particularly configured to be repeated operated, e.g., by repeatedly squeezing the bulb to apply suction alternating with draining the bulb to and removing the materials sucked from the body (e.g., the wound, surgical site, etc.). Thus, particularly in the later stage of healing, the bulb might not need to be squeezed for an extended period (e.g., days), but earlier in healing, squeezing more often may be preferable.

[0059] In general, the apparatuses described herein may maintain the pressure applied while collecting fluid within a target range (e.g., between about -50 mmHg and about -125 mmHg, e.g., between about -60 mmHg and about -125 mmHg, etc.) while the amount of fluid within the bulb is at least 30% (at least 31%, at least 32%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, etc.) of the total fill volume of the bulb. This is in sharp contrast to prior art drainage bulbs, which typically sharply reduce pressure when the amount of fluid collected in the bulb exceeds between about 10% and 20% (e.g., less than 20%), as was seen in FIG. 2B. In FIG. 2B, the pressure profile shows that the pressure from a bulb 203 without a rib as described herein dropped below the optimal negative pressure range (e.g., less than about -80 mmHg in this example) when the volume of fluid collected was less than 10 mm, or about 10% (or less) of the total volume (of 100 mL) of the bulb. In contrast, as shown in FIG. 3B, a bulb including an internal rib may maintain the pressure within the optimal negative pressure range (e.g., between about -50 mmHg and -125 mmHg, or between about -80 mmHg and -125 mmHg) until almost the entire filling volume of the bulb was full of collected fluid.

[0060] The differences between the negative pressure profiles of bulb 203 compared to bulb 303 may be attributed to the physical differences between the two, and the resulting mechanical pumping characteristics. For example, the greater thickness of the walls 309 compared to the thinner walled bulb 203 may create a greater spring force as the bulb 303 returns to the elliptical shape. The localized region of 308 of greater thickness (internal rib) may “flatten” the curve of the negative pressure profile compared to the bulb 203. The greater length L2 of the bulb 303 may elongate the negative pressure profile (along the x-axis) compared to the bulb 203. FIGS. 4A-10B show example bulbs with different force modulating features illustrating how each of- 13 -SG Docket No.: 14450-716.600these factors may individually influence the negative pressure profile / performance of a bulb during fluid collection.

[0061] Without being bound by theory, however, one key factor in extending the ability of the bulb to remain within the target optimal pressure range (e.g., between about -50 mmHg and - 125 mmHg) may be the ratio of the spring force between the wall of the bulb and the spring force modulator (e.g., one or more ribs). For example in FIG. 3B the material forming the rib and the walls is the same (although in some examples this may not be the case; the spring force modulator may be formed of a different material). The spring force of the rib(s) is typically higher than the spring force of the wall of the bulb. The ratio of the spring force of the spring force modulator to the spring force of the wall of the bulb (e.g., rib, wall) may be greater than 1, and in particular, may be 1.1 or greater (e.g., 1.2 or greater, 1.25 or greater, 1.3 or greater, 1.35 or greater, 1.4 or greater, 1.45 or greater, 1.5 or greater, 1.8 or greater, 1.9 or greater, 2 or greater, 2.2 or greater, 2.5 or greater, etc.). In some examples the ratio of the spring force of the spring force of the spring force modulator to the spring force of the wall of the bulb may be between 1.1 and 5 (e.g., between 1.1 and 4.5 between 1.1 and 4, between 1.1 and 3.5, between 1.1 and 3, between 1.1 and 2.5, between 1.1 and 2.0, etc.). The spring force of the wall of the bulb may be estimated from a bulb having the same dimensions, but without the spring force modulator being present. The spring force of the spring force modulator configured as a rib may be estimated from a ring having the dimensions of the rib, formed of the same material (which may include the thickness of the wall where the rib is in communication with the wall).

[0062] The spring force of the apparatus (e.g., the overall spring force) is the combination of the component spring forces of the spring force modulator (e.g., rib) and the spring force of the wall of the bulb, which may operate in parallel. Thus, the spring force modulator modifying the spring force of the wall of the bulb may result in a complex spring force behavior and the resulting relatively constant pressure profile when collecting fluid.

[0063] FIGS. 4A and 4B show example section views and a negative pressure graph, respectively, for an example bulb 403. The example of bulb 403 shows how a thickness of the walls 409 may affect the negative pressure performance. Compared to the bulb 203 of FIG. 2A, the thickness T2 of the walls 409 is greater than the thickness Ti of the walls 209. In this case, the thickness T2 of the walls 409 is the same as the thickness T2 of the walls 309 of bulb 303 (FIG. 3A). The length L3 of the bulb 403 is almost the same as the length Li of bulb 203 (although L3 is slightly longer due to the increased thickness of the walls 409). The graph of FIG. 4B shows that the increased wall thickness of bulb 403 provides a greater overall negative pressure compared to bulb 203. This may be attributed to the greater spring force provided by the thicker walls 409 compared to those of bulb 203. However, there is a region a at the beginning of - 14 -SG Docket No.: 14450-716.600fluid collection where the magnitude of negative pressure is higher than the maximum negative pressure Pi of the optimal pressure range OPR. In some cases, this may be considered too high for clinical application. Also, similar to the performance of bulb 203, the negative pressure drops dramatically by the time about 25 mL of fluid is collected in the bulb 403.

[0064] Generally, a greater wall thickness may increase the spring force provided by a bulb, depending on the internal volume, geometry, material properties (e.g., stiffness), and / or other factors. For example, the wall thickness may need to be increased with a larger internal bulb volume in order to create sufficient negative pressure. In some examples, a bulb having an internal volume of about 400 mL may have a wall thickness ranging from about 200 mL to about 600 mL.

[0065] FIGS. 5A and 5B show example section views and a negative pressure graph, respectively, for an example bulb 503. This example shows how the length of the bulb 503 may affect the negative pressure performance. The length L2 of the bulb 503 is greater than the thickness Li of the bulb 203 (FIG. 2A). The thickness Ti of the walls 509 is the same as the thickness Ti of the walls 209 of bulb 203. The graph of FIG. 5B shows that the increased wall length of bulb 503 provides a similar negative pressure profile shape as that of the bulb 203, but the maximum pressure M (pressure peak) created by the bulb 503 is less than that of bulb 203. However, the bulb 503 is able to maintain some negative pressure (above zero) past the maximum volume Vi of fluid collected p. In this way, the longer bulb 503 appears to elongate the pressure profile along the x-axis, thereby having the ability to collect more fluid than the bulb 203.

[0066] FIGS. 6 A and 6B show example section views and a negative pressure graph, respectively, for an example bulb 603. This example shows how a varied wall thickness of the bulb 603, particularly a wall having an outer protruding feature 612, may affect the negative pressure performance. The outer protruding feature 612 protrudes outward from an outer surface of the walls 609. In this case, the outer protruding feature 612 is in the form of a rib around an outer circumference of the bulb 603. The graph of FIG. 6B shows that the addition of the outer protruding feature 612 increases the overall negative pressure performance compared to bulb 203, but creates a region a at the beginning of fluid collection where the magnitude of negative pressure is higher than the maximum negative pressure Pi of the optimal pressure range OPR. In addition, the pressure drops dramatically to zero right before the maximum volume Vi capacity of the bulb 603. This pressure graph shape may be attributed to the localized greater wall thickness of the outer protruding feature 612 providing a greater spring force due, similar to the thicker walled bulb 404, but with a more flattened curve due to the unique spring force modulation caused by the location and shape of the outer protruding feature 612.- 15 -SG Docket No.: 14450-716.600

[0067] FIGS. 7A and 7B show example section views and a negative pressure graph, respectively, for an example bulb 703. This example shows how a varied wall thickness of the bulb 703, particularly a wall having an inner protruding feature 708, may affect the negative pressure performance. The inner protruding feature 708 protrudes from an inner surface of the walls 709. In this case, the inner protruding feature 708 is in the form of a rib around an inner circumference of the bulb 703. The graph of FIG. 7B shows that the addition of the inner rib 708 increases the overall negative pressure performance compared to bulb 203. This may be attributed to the localized greater wall thickness of the outer protruding feature 712 providing a greater spring force and a flattened curve. However, there is a region -a at the beginning of fluid collection where the magnitude of negative pressure could be higher, and a region -P at the end of fluid collection indicating that negative pressure dropped to zero before reaching the maximum volume Vi capacity of the bulb 703.

[0068] FIGS. 8A-8C and 9A-9C compare compressed states of the bulb 203 and the bulb 703, illustrating how the inner protruding feature 708 of the bulb 703 may affect negative pressure performance. FIGS. 8A-8C show the bulb 203 being compressed by a manual compression force F on opposing sides. As shown, the walls 209 collapse such that the inner surfaces of the walls 209 contact each other, thereby emptying a majority of the internal volume (e.g., of air) from the internal chamber of the bulb 203. FIGS. 9A-9C show the bulb 703 being compressed by the same manual compression force F as applied to the bulb 203. The inner protruding feature 708 limits the amount that the bulb 703 compresses inward, thereby emptying less of the internal volume (e.g., of air) from within the internal chamber of the bulb 703 compared to the bulb 203. In this way, the inner protruding feature 708 can act as a negative pressure magnitude limiter that provides a less-efficient squeeze than the bulb 203. The benefits of this feature include: the pressure / volume profile created by the bulb 703 is similar to thicker wall (e.g., FIG. 4A), external rib (e.g., FIG. 6A) and their combination; limiting the amount that the bulb 703 compresses helps to “flatten” the negative profile curve by the reducing the pressure amplitude between peak and partial or full fluid collection; limiting the amount that the bulb 703 compresses helps to keep the pressure magnitude from breaching past the maximum negative pressure Pi of the optimal pressure range OPR (in this case, about -125mmHg ); and there is minimal loss of fluid capacity.

[0069] Counterintuitively, the spring force modulators described herein may be internal to the bulb, e.g., within the collection volume of the bulb, while still maintaining the pressure profile within the desired pressure range (e.g., between about -50 mmHg and -125 mmHg), and despite limiting the ability of the bulb to collapse. Furthermore, in some cases it may be beneficial to arrange the spring force modulator (e.g., rib(s)) within the collection volume of the - 16 -SG Docket No.: 14450-716.600bulb as it may prevent over-collapse of the bulb (e.g., which may result in an undesired spike in the pressure profile when released).

[0070] FIGS. 10A and 10B show example section views and a negative pressure graph, respectively, for an example bulb 1003. This example shows how a combination of a longer length L3 and an inner protruding feature 1008 may affect the negative pressure performance. Specifically, the length L3 is greater than the length Li of the bulb 203, and the bulb 703 includes an inner protruding feature 1008 that protrudes from an inner surface of the walls 1009. The graph of FIG. 10B shows that the combination of these features increases the overall negative pressure performance, and flattens and lengthens the negative pressure curve, compared to bulb 203. In addition, the bulb 1003 is able to maintain some negative pressure (above zero) past the maximum volume Vi of fluid collected p. However, there is a region -a at the beginning of fluid collection where the magnitude of negative pressure could be higher to remain within the target (optimal) pressure range.

[0071] Returning to FIGS. 3A and 3B, a negative pressure profile that remains within the optimal pressure range OPR is accomplished using a bulb 303 that includes a combination of a greater wall 309 thickness, greater bulb length L2, and includes an inner protruding feature 308.

[0072] It should be noted that a desired negative pressure profile (e.g., within a predetermined range) may be accomplished using one or more of the spring force modulating features described herein. For example, other factors that may influence the spring force and resulting negative pressure profile / performance of a bulb may include the type of material and material properties of the bulb (e.g., elasticity, durometer, hardness, flexibility, etc.), size of the bulb (e.g., maximum volume, fluid capacity, etc.) and / or shape of the bulb (e.g., ellipsoid, spherical, etc.). The addition of thicker walls, greater length, and / or one or more inner and / or outer protrusions may affect the negative pressure profile of bulbs made of different materials, having different sizes (e.g., maximum volume Vi), and / or having different shapes (e.g., ellipsoid, spherical) differently. Thus, the spring force modulating features described herein can be used in any combination to achieve a desired negative pressure profile.

[0073] The optimal negative pressure range (OPR) may vary, for example, depending on the application, an industry standard of maximum and / or minimum pressure, and / or desired pumping efficiency. As discussed previously, the OPR may range from a minimum negative pressure of about -80 mmHg to a maximum negative pressure Pi of about -125 mmHg. In some cases, the minimum negative pressure may range anywhere from -50 mmHg to -100 mmHg. In some cases, the maximum negative pressure Pi may range anywhere from -100 mmHg to -150 mmHg. Further, what is deemed acceptable performance of a bulb in relation to a desired negative pressure profile may vary. For example, it may be acceptable for a bulb to apply a negative - 17 -SG Docket No.: 14450-716.600pressure within the predetermined range during at least 30%, at least 35%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or 100% of the maximum volume Vi of fluid capacity of the bulb.

[0074] The example bulbs of FIGS. 3A-10B have an internal volume (e.g., maximum internal chamber volume (Vi)) of about 100 mL. However, the bulbs described herein may include those having a different internal volume than 100 mL. In general, the internal volume may be suitable for being at least partially filled with a squeeze of the person’s hand. In some examples, the internal volume of the bulbs may range from about 50 mL to about 600 mL (e.g., 50 mL, 90 mL, 95 mL, 100 mL, 105 mL, 110 mL, 150 mL, 200 mL, 300 mL, 400 mL, 450 mL, 500 mL or 600 mL).

[0075] FIGS. 11A-11G shows section views of example bulbs having other variations of spring force modulators.

[0076] FIG. 11A shows a bulb having an inner protruding rib 1108 on an inner surface of the bulb that forms channel 1109 on an outer surface of the bulb. The inner protruding rib 1108 may be referred to as a hollow rib.

[0077] FIG. 1 IB shows a bulb having an inner protruding rib 1118 that is tilted (at a nonparallel angle) with respect to the minor axis of the bulb.

[0078] FIG. 11C shows a bulb having two inner protruding ribs 1128a and 1128b, which are in a crossed configuration. Each of the ribs 1128a and 1128b are tilted (at a non-parallel angle) with respect to the minor axis of the bulb.

[0079] FIG. 11D shows a spherically shaped bulb.

[0080] FIG. HE shows a bulb having three inner protruding ribs 1138a, 1138b, and 1138c, which are in a parallel configuration. Each of the ribs 1138a, 1138b, and 1138c are parallel with respect to the minor axis of the bulb.

[0081] FIG. 1 IF shows a bulb having four inner curved struts 1148a and 1148b (two other struts not shown). The ends of the struts 1148a and 1148b (and the two other struts not shown) connect to the inner walls of the bulb, but do not connect to the inner walls of the bulb along the length of the struts.

[0082] FIG. 11G shows a bulb having two inner straight struts 1158a and 1158b. Each of the struts 1158a and 1158b cross the inner chamber of the bulb across the minor axis of the bulb.

[0083] The example bulbs and spring force modulating features shown in FIGS. 1A-11G are presented as examples. Other examples and variations, and combinations thereof, that are not shown are also covered by the embodiments described herein.

[0084] In some examples, the spring force modulator includes one or more structures that are not integrally formed in the bulb walls. For example, the spring force modulator may include one - 18 -SG Docket No.: 14450-716.600or more ribs or frames that is / are formed separately from the bulb and configured to be placed within the inner chamber of the bulb. Alternatively or additionally, the one or more ribs or frames may be configured to be placed over the outer surface of the bulb. The one or more ribs or frames may be configured to provide some resistance to the inward compression force created by squeezing the bulb, thereby affecting the negative pressure profile as the bulb fills with fluid, as described herein. Such a feature may act as a spring that is positioned to function in parallel with the natural spring of the bulb that returns the bulb walls to their lowest mechanical energy state. The one or more ribs or frames may be made of the same material as the bulb (e.g., polymer) or a different material, such as a shape memory metal (e.g., nitinol).Drain Pump System

[0085] As discussed previously, management of the wound drainage systems requires a conscientious effort on the part of the patient to empty the bulb(s) in a timely manner. This may be difficult in situations in which finding a private place to do so is not convenient. This means that the bulb(s) may remain in a partially filled or fully filled state for some time before emptying and recharging, decreasing the effectiveness of the drainage system. The drain pump systems described herein can allow a patient to efficiently and conveniently empty and recharge the bulb pump(s).

[0086] FIG. 12 shows an example drain pump system 1200 according to some embodiments. A first end of a bulb 1203 includes a first connector 1252 that is fluidly coupled to a first tube 1256, which is fluidly coupled to a drain 1259. The drain 1259, which is generally provided by the surgeon, may be arranged to drain fluid from a tissue site in need of drainage. A second end of the bulb 1203 includes a second connector 1257 that is fluidly coupled to a second tube 1258, which is fluidly coupled to a fluid collection bag 1255. The example shown includes one bulb 1203; however, the system 1200 may include more than one bulb 1203 (e.g., 2, 3, 4, 5, 6 or more bulbs).

[0087] In this example, a first one-way valve 1251 is coupled to the first end of the bulb 1203 to control the flow of fluid from the first tube 1256 into the bulb 1203, and a second oneway valve 1253 is coupled to the second end of the bulb 1203 to control the flow of fluid from the bulb 1203 into the fluid collection bag 1255. Also in this example, the second tube 1258 includes a quick connector 1267 that is configured to allow disconnection of the bag 1255 from the bulb 1203 without fluid spillage. The fluid collection bag 1255 may include a third one-way valve 1265 to control the flow of fluid into the bag 1255, and an air vent 1263 that allows the venting of air. One or more of the one-way valves 1251, 1253 and 1265 may include any of a- 19 -SG Docket No.: 14450-716.600number of types of one-way valves, such as a duckbill valve, ball check valve, diaphragm valve, swing check valve, and / or butterfly valve.

[0088] In some examples, the collection bag 1255, the second tube 1258 and the connector 1267 are sized and arranged such that the system 1200 nearly occupies the same space as the bulb 1203 itself. This may allow for discrete positioning of the system 1200 on or near the person. For example, the collection bag 1255, the second tube 1258 and the connector 1267 may be positioned next to the bulb 1203 so that they may fit, for example, into a garment cavity designed for a singular bulb.

[0089] During use, the patient may squeeze the bulb 1203, which drives fluid towards the collection bag 1255 through the second one-way valve 1253 and the third one-way valve 1265. During squeezing, the first one-way valve 1251 prevents fluid from retrograde flow into the drain 1259. The first one-way valve 1251 also allows fluid flow from drain 1259 into bulb 1203. After squeezing, the second one-way valve 1253 closes, allowing negative pressure to be established with the bulb 1203 and the drain 1259. The bulb 1203 may include one or more spring force modulating features, as described herein, that maintains the negative pressure within a predetermined range as the walls of the bulb 1203 return to an expanded state. The fluid collection bag 1255 can be disconnected from the bulb 1203 via the quick connector 1267 for disposal of fluid and replacement with a new bag at any point of the cycle.

[0090] One of the advantages provided by the system 1200 is that the bulb 1203 may be squeezed at any time during the filling cycle. For example, even after collecting only 25 mL in the bulb 1203, the user may squeeze the bulb 1203 to empty fluid and recharge the system 1200. The high magnitude of negative pressure provided by the bulb 1203 is then re-established to improve the performance of the system 1200.

[0091] Another advantage provided by the system 1200 is that the bulb 1203 may be squeezed without needing privacy, a sink, or opening the system. This provides for relatively easy emptying and recharging compared to the current standard of care. Thus, a user may be more inclined to these operations and thereby allow for improved healing.

[0092] A further advantage provided by the system 1200 is that the addition of the collection bag 1255 increases the capacity of the system (and fluid collected) without requiring the user to open the system 1200. Reducing the frequency of opening the system 1200 also reduces the risk of unwanted bacteria from colonizing the bulb 1203, thereby reducing the chance of patient infection.

[0093] Another advantage provided by the system 1200 is that the collection bag 1255 may be a range of sizes, for example, from about 100 mL to 1,000 mL volume capacity. High fluid- 20 -SG Docket No.: 14450-716.600output, particularly during the early days post-operation, could be best managed with a larger bag. Low fluid output, often later during the healing phase may be managed with a smaller bag.

[0094] An additional advantage provided by the system 1200 is that the collection bag 1255 may offer measurement indicators and a superior way of measuring fluid collected compared to conventional methods (e.g., collection cups), which is important information for the clinician. For example, in breast reconstruction, drains are often removed when the fluid collected is down to about 25 mL per day. The collection bag 1255 may allow for more reliable collection of the fluid by reducing the risk of fluid spillage.

[0095] Further, since the bulb 1203 is more efficient at pumping fluid compared to conventional bulbs, the system 1200 may not need as many bulbs 1203. For example, a pump system having four to six conventional bulbs may only need one of the bulbs 1203 (e.g., with one or more of the spring force modulators described herein) to provide the same draining effectiveness. Fewer bulbs 1203 may make it easier for the system 1200 to be discreetly worn by the patient.

[0096] The drain pump system 1200 may improve patient compliance and the quality of the negative pressure delivered to the drain by allowing less exposure of system 1200 to atmosphere, thereby reducing chance of microbial colonization because the collection bag 1255 adds fluid capacity to the system 1200. The system 1200 thereby becomes a conduit to the healing tissue below the skin. Further, because collecting fluid by squeezing the bulb 1203 is more efficient and less burdensome on the patient compared to standard bulbs, the user may be more inclined to periodically squeeze the bulb 1203 at shorter intervals. Overall, the system 1200 may maintain a greater magnitude of negative pressure during treatment, with the potential of improved healing outcomes.

[0097] FIGS. 13 and 14 compare negative pressure profiles using the drain pump system 1200 with the bulb 203 versus the drain pump system 1200 with the bulb 303, respectively. In both cases, the bulb (203 or 303) was squeezed multiple times, each after every 30 mL of fluid is collected. The graph of FIG. 13 shows that the negative pressure dropped significantly below the optimal pressure range OPR with each squeeze of the bulb 203 (similar to that shown in FIG. 2A). This indicates that the bulb 203 used in the system 1200 fails to keep the magnitude of negative pressure within the target range, despite repeated squeezing every 30 mL. The graph of FIG. 14 shows that the negative pressure was maintained well within the optimal pressure range OPR with each squeeze of the bulb 303 (e.g., similar to that shown in FIG. 3A). This indicates that the improved bulb 303 in combination with the system 1200 offers a high-performance solution to the problem of efficient fluid collection. In addition, the features of system 1200 (e.g., collection bag 1255 and valves) provide an encompassing solution for the user that can enhance- 21 -SG Docket No.: 14450-716.600clinical outcomes by increasing bulb performance and / or encouraging the maintenance of higher- magnitude negative pressures within the system 1200.

[0098] In general, the apparatuses described herein, e.g., the bulbs including the spring force modulator, may allow the user to significantly reduce the number of times that the patient needs to “pump” (e.g., squeeze the bulb) in order to maintain pressure to withdraw fluid during use. Thus, in FIG. 14, the bulb is shown being squeezed four times before removing 100 ml of fluid while within the optimal pressure range (e.g., between -50 mmHg and -125 mmHg), however, it should be apparent that an equivalent effect of removing fluid while pressure is maintained in the optimal pressure range may be accomplished with much fewer activations (pumps) of the bulb, assuming that the bulb has an equivalent volume (e.g., 100 mL or more). For example, as shown in FIG. 3B, the pressure profile per volume collected may allow the bulb to be pumped three or fewer times (two or fewer times, or even one time), as compared with bulbs without the spring force modulator (e.g., FIG. 13).

[0099] Any of the bulbs described herein may include ergonomic considerations related to the human factors element of squeezing the bulb. Some of these ergonomic considerations may include: the size and / or shape of the bulb prior to squeezing; the size and / or shape of the bulb after fully squeezing; the force / pressure required to squeeze the bulb; the range of motion associated with squeezing the bulb; and / or the speed of actuation when squeezing the bulb. The unique geometry and / or features of the bulbs described herein enables the user to gain advantage of superior negative pressure profile without undue actuation burden.

[0100] Returning to FIGS. 8C and 9C, in some cases, the forces F were measured using a system shown in these figures, where the hemispherical shaped elements are attached to force gauges to measure the required force to squeeze respective bulbs. The maximum force required to fully squeeze the bulbs were recorded to assure that maximum force does not exceed an expected force applied by the human hand.

[0101] FIG. 15A shows another example of a bulb assembly as described herein, similar to that shown in FIG. 10A. The assembled bulb pump 1500 (bulb assembly) is shown on the left, and isolated components that form parts of the bulb assembly are shown on the right. As mentioned, the bulb assembly may also be referred to as a surgical drain pump, bulb pump or simply bulb. The bulb assembly 1500 in FIG. 15A includes a bulb having one or more walls 1511 that define an inner chamber 1512 and an opening though a connector inlet 1502 that provides fluid access to the inner chamber, wherein the one or more walls are configured to collapse inward upon application of a manual compression force to take on a collapsed state. Once the manual compression force is released from the wall of the bulb, the wall, which may be formed of an elastomeric material is configured to provide a spring force to return to the one or - 22 -SG Docket No.: 14450-716.600more walls to an expanded state and to supply a negative pressure via the opening in the inlet connector to draw fluid into the inner chamber. The bulb in FIG. 15A, as in FIGS. 7 and 10, described above, also includes an inner protruding feature 1518 that forms a spring force modulator that is configured to modulate the spring force of the one or more walls (at the mid region of the wall 1506). The spring force modulator in this example is configured as an inner protrusion that protrudes from an inner surface of the wall 1511 within the inner chamber. The inner protrusion is configured to limit an extent to which the one or more walls collapse inward upon application of the manual compression force. This, surprisingly, causes the one or more walls to maintain the negative pressure within a predetermined range as the one or more walls return to the expanded state, as illustrated in the examples above. The bulb is generally elongated, having a longer length, L, as compared with the width, W. This is generally a prolate spheroid (or ovoid-shaped) wall with an internal protruding feature on the minor axis circumference, and the resulting shape affects the negative pressure performance. The device shown in FIG. 15A may have a negative pressure profile that remains within the optimal pressure range OPR as described above. The body of the bulb may be formed of a material having properties (e.g., elasticity, durometer, hardness, flexibility, etc.), selected to maintain the operational pressure following squeezing so that the optimal negative pressure range (OPR) is maintained. As discussed previously, the OPR may range from a minimum negative pressure of about -80 mmHg to a maximum negative pressure Pi of about -125 mmHg. In some cases, the minimum negative pressure may range anywhere from -50 mmHg to -100 mmHg. In some cases, the maximum negative pressure Pi may range anywhere from -100 mmHg to -150 mmHg. Further, what is deemed acceptable performance of a bulb in relation to a desired negative pressure profile may vary. For example, it may be acceptable for a bulb to apply a negative pressure within the predetermined range during at least 30%, at least 35%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or 100% of the maximum volume Vi of fluid capacity of the bulb.

[0102] In any of these examples the thickness of the wall may be between about 1.0 mm (or preferably about 1.2 mm, more preferably about 1.5 mm or more, e.g., 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, etc.) and about 4 mm (e.g., 4.2 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6 mm, etc.). The wall thickness may be constant, e.g., uniformly thick, along the sides the bulb, or may vary (e.g., within this range). The protrusion may be between about 1.5 and 4 fold thicker than the general wall thickness (e.g., between about 1.8x and 4x, between about 2x and 4x, between about 1.5x and 3.5x, between about 1.8x and 3.5x, between about 2x and 3.5x, between about 1.5x and 3.5x, between about 1.8x and 3.5x, between about 2x and 3.5x, etc.). For example, the maximum thickness of the protrusion may be between about 3.5 mm and about 15 mm (e.g., between about - 23 -SG Docket No.: 14450-716.6003.5 mm and 12 mm, between about 3.5 mm and 10 mm, between about 4 mm and 15 mm, between about 4 mm and 13 mm, between about 4 mm and 10 mm, between about 4.5 mm and 15 mm, between about 4.5 mm and 12 mm, between about 4.5 mm and 10 mm, etc.).

[0103] In general, the thickness of the spring force modulator (e.g. the protrusion) may be measured from the outer surface of the bulb to the inner surface (e.g., the surface of the bulb interior, e.g., may include the wall thickness of this region of the bulb). The spring force modulator protrusion may protrude from the wall by the difference between the protrusion thickness and the wall thickness. For example, if the wall thickness is 1.2 mm, the protrusion may extend between 0.6 mm and 6 mm from the inner surface of the wall (e.g., between 0.6 mm and 5 mm, between 0.6 mm and 4 mm, between 0.6 mm and 3 mm, between 0.6 mm and 2 mm, between 0.6 mm and 1 mm, between 0.8 mm and 6 mm, between 1 mm and 6 mm, between 0.8 mm and 4 mm, between 0.8 mm and 3 mm, between 0.8 mm and 2.5 mm, etc.).

[0104] In the example bulb assembly shown in FIG. 15A, the bulb includes a distal connector inlet 1502 coupled to the distal end opening of the drain bulb body. The connector inlet engages with a collar inlet 1503 to which a one-way valve 1504 is also attached. The valve 1504 in this example is a single slit valve; any other valve may be used. The valve may be configured to permit fluid flow into the bulb, but may resist leaking of liquid out of the bulb chamber 1512, back through the inlet 1502. An inner retaining ring 1505 may secure the collar, inlet and valve in position at the distal end of the bulb. A similar structure may be present at the proximal end of the bulb, but with the proximal valve 1504’ inverted, and including a connector outlet 1509. The same type of one-way valve may be used, or a different valve may be used. For example, in FIG.15, the bulb assembly includes connector outlet 1509, coupled to a collar outlet 1508, outlet valve (one way valve) 1504’ and an inner retaining ring 1507. In some examples the bulb may include a control valve at either end to open / close the inlet / outlet. For example a control valve (not shown) on the proximal end may be actuated (e.g., turned, rotated, etc.) to close off the outlet to prevent leak or loss of fluid until the connector outlet is connected to a collection device (e.g., container, such as a bag, tube, etc.). A stopcock-type valve may be included. Any of the bulbs described herein may include the additional assembly components shown in FIG. 15 A.

[0105] The valves orientation is configured so that the device operates as described above; squeezing the bulb may push the air (or other fluid) out of the proximal end of the device, including collecting fluid in the bulb, and creating negative pressure up to the ideal negative pressure level; the negative pressure may be experienced by the distal end of the device, through the distal end connector and one-way valve. The resulting negative pressure may be maintained as fluid is collected. This is illustrated in FIG. 15B showing a graph of pressure (negative - 24 -SG Docket No.: 14450-716.600pressure) within the bulb assembly vs. total fluid collected. In FIG. 15B, the solid line 1537 shows the pressure vs. fluid collected relationship for a comparable bulb that does not include a spring force modulator (e.g., inner ridge within the designated parameter range), showing that the pressure drops quickly as fluid is collected. In contrast the bulb assembly shown in FIG. 15A may instead have a much lower drop in pressure upon release of the squeeze (compression force) applied. This is shown by the dashed line 1535. The sawtooth-shaped line shown in FIG. 15B, 1533 may represent a pressure profile when the device is repeatedly squeezed and released to pump fluid, which may be useful during initial operation, to remove a lot of fluid in a relatively short period of time using the relatively high pressures that may be maintained. In this case, the pressure may be continuously maintained in the target range 1531, 1535.

[0106] Any of the bulb assemblies described herein may be part of a system including a collection sub-assembly as well as the bulb assembly. For example, FIG. 16 illustrates one example of a system 1600 including a bulb assembly 1640 (sub-assembly) and a collection subassembly 1641. The bulb assembly may include a fastener (e.g., clip, such as a garment clip 1601) for fastening the bulb assembly to a patient (e.g., belt, pant, shirt, sleeve, etc.) so that it may be conveniently worn. The bulb assembly may also include tubing 1611 connecting to the connector outlet of the bulb assembly 1609 (which may be secured by a securement, e.g., zip tie, etc.) and to a quick disconnect 1613 (which may also be secured by a securement 1610). In FIG. 16 the bulb assembly includes a female quick disconnect 1613 that may connect to mating connector 1619 (e.g., male connector) on the collector sub-assembly 1641. The bulb assembly in this example also includes an optional male quick connector 1614 that may be swapped out for the female quick connector 1613 when the collector sub-assembly has a female connector or when one wants to connect to tubing directly. The male and female quick connect connectors may be linked by a tether 1615 for convenience. A label or flag 1612 may be included to mark or otherwise identify the bulb sub-assembly.

[0107] The collector sub-assembly 1641 in this example is a bag sub-assembly that allows collection (and approximate measurement) of the fluid volume collected into a bag 1616 (drainage bag). In this example, the bag also includes a fastener (e.g., clip) 1601’, and tubing connecting the inlet connector 1619 (shown as a male connector) to the inner volume of the drainage bag 1616. The bag may be emptied by opening a drainage port 1621, 1618 on the proximal end of the bag, which may be opened or closed (so that it may be continued to receive fluid). The collector (e.g., drainage bag 1616) may be calibrated to identify the volume of collected fluid and / or to uniquely identify the bag 1617.Multiple Drain Configurations- 25 -SG Docket No.: 14450-716.600

[0108] Any of the apparatuses (e.g., systems) described herein may include bulbs that are each attached to multiple drains. Attaching multiple drains to a single bulb may be desirable for users (e.g., patient, a clinician and / or a caregiver) in clinical use. This may, for example, increase the efficiency of draining. In some cases, multiple drains may be placed in different tissue sites within the patient body, thereby providing drainage of the different tissue sites upon squeezing a single bulb. This may also provide a simpler mechanism for the user since the user needs to only squeeze a single bulb to drain multiple drains.

[0109] There are some considerations to ensure adequate function of such a multiple drain configuration. For example, the drain tubing for each of the drains may need to be frequently “stripped” to dislodge fibrous and gelatinous material that may form on the inner lumen of the tubing, which may otherwise restrict flow. Such stripping may involve squeezing the restrictive material downstream towards and into the bulb. There are also unique considerations when attaching two or more drains to a negative pressure bulb. For example, both drains should maintain negative pressure during normal use. In addition, both drains should have features that allow for stripping and for maintaining adequate negative pressure and flow. Also, stripping one drain should not induce retrograde flow on the other drain(s). Retrograde flow may increase the possibility of inflammatory or infective material entering the body; and therefore, should be avoided as much as possible.

[0110] FIGS. 18 and 19 show example apparatuses (e.g., systems, assemblies, subassemblies) that have multiple drain configurations and features that address clinical considerations, such as providing a way to strip (dislodge) material from tubing leading to the multiple drains. These apparatuses include valve assemblies that include one or more valves that control fluid flow from the multiple drains to the bulb, and that reduce the occurrence of retrograde fluid flow during, for example, a stripping operation to unclog tubing. The one or more valves may include one or more one-way valves (i.e., check valves), one or more on-off valves (e.g., duckbill valve, ball check valve, diaphragm valve, swing check valve, and / or butterfly valve) and / or one or more switching valves (e.g., three-way valves).

[0111] Aspects of these apparatuses in FIGS. 18 and 19 may be combined with any of the features described herein. For example, the bulbs may be configured to fluidly connect to one or more fluid collection bags that are configured to collect the drained fluid, as described herein. Alternatively or additionally, the bulbs may include an air vent to allow venting of the bulbs. As another example, the bulbs may include any of the spring force modulators described herein. Additionally or alternatively, any of these apparatuses may include drain flushing features, as described herein.- 26 -SG Docket No.: 14450-716.600

[0112] FIG. 18 shows an example apparatus 1800 that has a multiple drain configuration and that is configured for the active management by a user. A bulb 1803 is fluidically coupled with a first drain 1859 and a second drain 1860. The first and second drains 1859, 1860 may be configured to being positioned below the patient’s skin 1801. The first and second drains 1859, 1860 may be positioned at the same tissue site or at different tissue sites of the patient. The first drain 1859 includes (or is coupled with) a first tube 1856, and the second drain 1860 includes (or is coupled with) a second tube 1857. The first tube 1856 and / or the second tube 1857 may be manually compressible so that a pinching force can be applied to strip the first tube 1856 and / or the second tube 1857 of fibrous and gelatinous material, as discussed herein.

[0113] The bulb 1803 may be configured to generate a negative pressure within the first and second tubes and the bulb upon manual compression (squeezing) of the bulb 1803. The bulb 1803 is configured to generate sufficient negative pressure to draw fluid from the patient’s body into the bulb 1803 via each of the first and second drains 1859, 1860 positioned within the patient’s body. In this example, the bulb 1852 includes a connector 1852 that is fluidly coupled with a first tube 1856 (which is fluidly coupled with the first drain 1859) and fluidly coupled with a second tube 1857 (which is fluidly coupled with the second drain 1860). In the example shown, a Y-connector 1805 connect provides a split to connect the bulb 1803 to both the first and second drains 1859, 1860. However, other connector and / or valve configurations may be used.

[0114] The apparatus 1800 includes a valve assembly that is configured to control fluid flow between and each of the first and second tubes 1856, 1857 and the bulb 1803. For example, a one-way valve 1851 is configured to limit or prevent fluid from backflowing out of the bulb 1803 into the first or second tubes 1856, 1857. In addition, a first on-off valve 1830 is configured to open and close fluid connection between the bulb 1803 and the first drain 1859, and second on-off valve 1832 is configured to open and close fluid connection between the bulb 1803 and the second drain 1860. During negative pressure conditions (e.g., during draining of the body tissue / cavity), both the first and second on-off valves 1830, 1832 may be open to allow efficient drainage from the body cavity.

[0115] The first and second on-off valves 1830, 1832 may be configured to allow tubing stripping function on one tube (one of first and second tubes 1856, 1857) without contralateral pressure (backflow) through the other tube (the other one of first and second tubes 1856, 1857). For example, to strip (dislodge material within) the first tube 1856, the first on-off valve 1830 may be open and the second on-off valve 1832 may be closed; then, the user may apply a pinching force on a first end 1841 of the first tube 1856 and move the pinching force along the first tube 1856 in a direction toward a second end 1840 the first tube 1856 (i.e., toward the bulb - 27 -SG Docket No.: 14450-716.6001803). In some cases, this stripping may be repeated as necessary. Since the second on-off valve 1832 is closed, any fluid and / or material flowing from the first tube 1856 toward the bulb 1803 will not enter the second tube 1857. Once the first tube 1856 is sufficiently stripped, the pinch may be released and the second on-off valve 1832 may be reopened to allow drainage from second drain 1860.

[0116] Likewise, to strip the second tube 1857, the second on-off valve 1832 may be open and the first on-off valve 1830 may be closed. Then, the user may apply a pinching force on a first end 1843 of the second tube 1857 and move the pinching force along the first tube 1857 in a direction toward a second end 1842 the second tube 1857 (i.e., toward the bulb 1803). Once the second tube 1857 is sufficiently stripped, the pinch force may be released and the first on-off valve 1830 may be reopened to allow drainage from first drain 1859.

[0117] To use the apparatus 1800, the bulb 1803 may be manually compressed to generate a negative pressure within the first and second tubes 1856, 1857. If the first and second on-off valves 1830, 1832 are open, the negative pressure can draw fluid from the tissue site of the patient into the bulb 1803 via each of the drains 1859, 1860. Prior to stripping material the first tube 1856, the second on-off valve 1832 may be closed to prevent retrograde flow back into the second tube 1857. Prior to stripping material the second tube 1857, the first on-off valve 1830 may be closed to prevent retrograde flow back into the first tube 1856.

[0118] FIG. 19 shows an example apparatus 1900 that has a multiple drain configuration, similar to the apparatus 1800 of FIG. 8, except that the apparatus 1900 includes a valve assembly that is configured to provide passive retrograde pressure / flow protection. The apparatus 1900 includes a first one-way valve 1950 coupled with a first tube 1956, and a second one-way valve 1951 coupled with a second tube 1957. The first one-way valve 1950 is configured to provide one-way fluid flow from a first drain 1959 to a bulb 1903. Likewise, the second one-way valve 1951 is configured to provide one-way fluid flow from a second drain 1960 to the bulb 1903. The first and / or second one-way valves 1950, 1951 may be part of a connector 1952, or may be separate from the connector 1952.

[0119] The configuration of apparatus 1900 allows the first and / or second tubes 1956, 1957 to be stripped without manual activation of valves (e.g., valves 1840, 1842 of apparatus 1800). That is, there are no valves that the user needs to activate or switch before or after stripping. This arrangement may be safer for the patient as each of the first and second drains 1959, 1960 is passively protected from retrograde flow by the respective first or second one-way valve 1950, 1951.Drain Flush Features- 28 -SG Docket No.: 14450-716.600

[0120] Any of the apparatuses described herein may include features that allow for fluid flushing of the tissue site. The ability to introduce fluid to a drain in a patient’s body may be clinically advantageous by reducing restrictive clots and fibrous material that may be inhibiting fluid flow, and / or to allow the clinician to directly treat the tissue space that is in contact with the drain. In some cases, antibiotics and / or other treatment agents may be included in the fluid that is introduced to the tissue site (e.g., instead of or in addition to flushing the tissue space). In some examples, a user (e.g., clinician) may flush a tissue space around the drain by pushing and / or pulling fluid into the drain repeatedly (e.g., in a cyclic fashion), which may help to dislodge undesirable material and / or encouraging any treatment agent movement within the tissue space.

[0121] FIGS. 20A-20C and 21 show example apparatuses that have drain flushing features. Aspects of these apparatuses may be combined with any of the features described herein. For example, the bulbs may be configured to fluidly connect to one or more fluid collection bags that are configured to collect the drained fluid, as described herein. Alternatively or additionally, the bulbs may include an air vent to allow venting of the bulbs. As another example, the bulbs may include any of the spring force modulators described herein. Additionally or alternatively, any of these apparatuses may include multiple drain configurations, as described herein.

[0122] FIGS. 20A-20C show an example apparatus 2000 that includes a port 2012 that is configured to allow the injection of a fluid (e.g., saline) and / or to allow for connection to a vacuum source. The apparatus 2000 includes a valve assembly that is configured to switch fluid access to a drain 2014 between the port 2012 and a bulb 2003. For example, a first on-off valve 2002 controls fluid communication between the bulb 2003 and the drain 2014, and a second on- off valve 2004 controls fluid communication between the port 2012 and the drain 2014. Thus, when the second on-off valve 2004 is open, a fluid (e.g., flushing fluid) injected into the port 2012 can reach a tissue space under the patient’s skin 2001 around the drain 2014. If the port 2012 is connected to a vacuum source and the second on-off valve 2004 is open, suction is applied to the drain 2014, causing fluid drainage from the tissue space around the drain 2014. When the apparatus 2000 is in a bulb suction mode, the first on-off valve 2002 is open and the second on-off valve 2004 is closed. The bulb 2003 can then be activated (e.g., squeezed) to provide negative pressure (suction) through the tubing 2010 to the drain 2014, thereby causing drainage fluid from the drain 2014 to flow toward the bulb 2003.

[0123] FIG. 20A illustrates a drain flushing condition where a positive pressure flow 2006 of flushing fluid is supplied to the drain 2014. The first on-off valve 2002 is closed and the second on-off valve 2004 is open. The flushing fluid can then be injected into the port 2012 to provide the positive pressure flow 2006 of flushing fluid to drain 2014, thereby flushing a drain space - 29 -SG Docket No.: 14450-716.600within the patient’s body around the drain 2014. Note that a distance 2016 between the second on-off valve 2004 and the skin 2001 may be minimized to reduce the chance of inflammatory or infective material entering the drain a tissue space around the drain 2014.

[0124] FIG. 20B illustrates the apparatus 2000 in a drain flushing condition where suction is applied to the drain 2014 via the port 2012 to pull fluid from the tissue space around the drain 2014. This condition is accomplished by closing the first on-off valve 2002 and opening the second on-off valve 2004, then pulling suction through the port 2012. The suction force provides a flow 2018 of fluid from the drain 2014 toward the port 2012. The amount of suction through the port 2012 may be controlled by controlling the negative pressure source (e.g., vacuum pump), thereby possibly providing a different amount of negative pressure than the bulb 2003 may provide. For example, the negative pressure applied through the port 2012 may be greater than can be applied by the bulb 2003.

[0125] FIG. 20C illustrates the apparatus 2000 in a fluid flushing injection and suction cycling condition. The first on-off valve 2002 is closed and the second on-off valve 2004 is open. Flushing fluid (positive pressure) and negative pressure (suction) are cyclically provided through the port 2012 and to the drain 2014. This cyclical positive and negative pressure may help to dislodge and clear blockages within the drain 2014, thereby improving flushing and draining of the tissue space around the drain 2014.

[0126] One or more of the flushing conditions shown in FIGS. 20A-20C may be repeated as necessary before, after or between instances of providing suction from the bulb 2003. For example, the patient or caretaker may provide suction to the drain 2014 via the bulb 2003 away from the clinician’s office, and the clinician may provide flushing of the drain 2003 via the port 2012 when the patient is in the clinician’s office.

[0127] FIG. 21 shows another example apparatus 2100 that is configured for flushing. The apparatus 2100 has similar features as the apparatus 2000 of FIGS. 20A-20C except a switching valve 2120 (e.g., three-way valve) coupled to the tubing 2110 replaces the two on-off valves 2002, 2004. In general, a switching valve 2120 is configured to select between multiple fluid paths. In this case, the switching valve 2120 is configured to switch fluid access to the drain 2114 between the bulb 2103 and the port 2112. For example, the switching valve 2120 may be placed in a first position that provides fluid communication between the bulb 2103 and the drain 2114, while closing fluid communication between the port 2112 and the drain 2114. This switching valve 2120 design may allow for same the suction, injection and cycling conditions described above with respect to FIGS. 20A-20C. Note that a distance 2116 between the switching valve 2120 and the skin 2101 may be minimized to reduce the chance of inflammatory or infective material entering the tissue space around the drain 2114.- 30 -SG Docket No.: 14450-716.600

[0128] When a feature or element is herein referred to as being “on” another feature or element, it can be directly on the other feature or element, or intervening features and / or elements may also be present. In contrast, when a feature or element is referred to as being “directly on” another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.

[0129] Terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and / or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “ / ”.

[0130] Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

[0131] Although the terms “first” and “second” may be used herein to describe various features / elements (including steps), these features / elements should not be limited by these terms, - 31 -SG Docket No.: 14450-716.600unless the context indicates otherwise. These terms may be used to distinguish one feature / element from another feature / element. Thus, a first feature / element discussed below could be termed a second feature / element, and similarly, a second feature / element discussed below could be termed a first feature / element without departing from the teachings of the present invention.

[0132] Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising” means various components can be co-jointly employed in the methods and articles (e.g., compositions and apparatuses including device and methods). For example, the term “comprising” will be understood to imply the inclusion of any stated elements or steps but not the exclusion of any other elements or steps.

[0133] In general, any of the apparatuses and methods described herein should be understood to be inclusive, but all or a sub-set of the components and / or steps may alternatively be exclusive, and may be expressed as “consisting of’ or alternatively “consisting essentially of’ the various components, steps, sub-components or sub-steps.

[0134] As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word “about” or “approximately,” even if the term does not expressly appear. The phrase “about” or “approximately” may be used when describing magnitude and / or position to indicate that the value and / or position described is within a reasonable expected range of values and / or positions. For example, a numeric value may have a value that is + / - 0.1% of the stated value (or range of values), + / - 1% of the stated value (or range of values), + / - 2% of the stated value (or range of values), + / - 5% of the stated value (or range of values), + / - 10% of the stated value (or range of values), etc. Any numerical values given herein should also be understood to include about or approximately that value, unless the context indicates otherwise. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. It is also understood that when a value is disclosed that “less than or equal to” the value, “greater than or equal to the value” and possible ranges between values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value “X” is disclosed the “less than or equal to X” as well as “greater than or equal to X” (e.g., where X is a numerical value) is also disclosed. It is also understood that the throughout the application, data is provided in a number of different formats, and that this data, represents endpoints and starting points, and ranges for any combination of the data points. For example, if a particular data point “10” and a particular data point “15” are disclosed, it is understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15 are- 32 -SG Docket No.: 14450-716.600considered disclosed as well as between 10 and 15. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0135] Although various illustrative embodiments are described above, any of a number of changes may be made to various embodiments without departing from the scope of the invention as described by the claims. For example, the order in which various described method steps are performed may often be changed in alternative embodiments, and in other alternative embodiments one or more method steps may be skipped altogether. Optional features of various device and system embodiments may be included in some embodiments and not in others. Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the invention as it is set forth in the claims.

[0136] The examples and illustrations included herein show, by way of illustration and not of limitation, specific embodiments in which the subject matter may be practiced. As mentioned, other embodiments may be utilized and derived there from, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. Such embodiments of the inventive subject matter may be referred to herein individually or collectively by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept, if more than one is, in fact, disclosed. Thus, although specific embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.- 33 -SG Docket No.: 14450-716.600

Claims

CLAIMSWhat is claimed is:

1. A medical drain system comprising: a bulb having a first connector configured to be fluidly coupled to a first medical drain within a patient’ s body and a second connector configured to be fluidly coupled to a second medical drain within the patient’s body, wherein the bulb is configured to generate a sustained negative pressure within both the first and second medical drains upon manual compression of the bulb, wherein the bulb is configured to generate sufficient sustained negative pressure to draw fluid from a patient’s body into the bulb via each of the first and second drains positioned within the patient’s body for greater than 1 minute; and a valve assembly that is configured to control fluid flow between a first tube coupled to the first connector, second tube coupled to the second connector and the bulb, wherein the valve assembly is configured to: maintain the negative pressure within the first and second tubes and the bulb upon movement of a pinching force applied along one or both of the first and second tubes; and limit or prevent fluid from backflowing out of the bulb into the first or second tubes.

2. The system of claim 1, further comprising the first drain and the second drain.

3. The medical drain system of claim 1, wherein the valve assembly includes a first one-way valve and a second one-way valve, wherein the first one-way valve is configured to provide one-way fluid flow from the first drain to the bulb, and wherein the second one-way valve is configured to provide one-way fluid flow from the second drain to the bulb.

4. The medical drain system of claim 1, wherein the valve assembly includes: a first on-off valve that is configured to open and close fluid connection between the bulb and the first drain; a second on-off valve that is configured to open and close fluid connection between the bulb and the second drain; and a one-way valve configured to limit or prevent fluid from flowing out of the bulb and into the first or second tubes.- 34 -SG Docket No.: 14450-716.6005. The medical drain system of claim 4, wherein the valve assembly further comprises a y- connector that fluidly couples the first and second tubes to the bulb.

6. The medical drain system of claim 1, wherein the first and second drains are configured to be placed within different tissue site locations within the patient’s body.

7. The medical drain system of claim 1, further comprising one or more additional drains, other than the first and second drains, that is / are fluidly coupled with the bulb.

8. The medical drain system of claim 1, further comprising a fluid collection bag that is arranged to collect fluid from the bulb.

9. The medical drain system of claim 8, wherein the bulb includes a first opening that provides a fluid access between the bulb and each of the first and second tubes, wherein the bulb further includes a second opening that provides fluid access between the bulb and the fluid collection bag.

10. The medical drain system of claim 9, further comprising a one-way valve that is configured to limit or prevent fluid backflow from the fluid collection bag into the bulb.

11. The medical drain system of claim 1, wherein at least one of the first and second drains includes a plurality of holes for efficiently collecting fluid from the patient’ s body.

12. The medical drain system of claim 1, wherein the bulb comprises a spring force modulator configured to modulate a spring force provided the bulb, wherein the spring force modulator includes one or more protrusions that protrude from an inner surface of the bulb, the spring force modulator configured to limit an extent to which the bulb collapses inward upon application of the manual compression, thereby causing the bulb to maintain the negative pressure within a predetermined range as the bulb returns to an expanded state.

13. A method of using a medical drain system, the medical drain system comprising a first drain including a first tube fluidly coupled with a bulb, and a second drain including a second tube fluidly coupled with the bulb, wherein the method comprises: manually compressing the bulb to generate a negative pressure within the first and second tubes and the bulb, wherein the negative pressure draws fluid from the patient’s body into the bulb via each of the first and second drains positioned within the patient’s body; and- 35 -SG Docket No.: 14450-716.600dislodging material within at least one of the first and second tubes by moving a pinching force applied along the at least one of the first and second tubes in a direction toward the bulb, wherein the negative pressure within the first and second tubes and the bulb is maintained while applying and moving the pinching force, and wherein one or more one-way valves limits or prevents fluid from backflowing out the bulb and into the at least one of the first and second tubes.

14. The method of claim 13, further comprising positioning the first and second drains within a patient’s body.

15. The method of claim 13, wherein the medical drain system includes a first one-way valve and a second one-way valve, wherein the first one-way valve provides one-way fluid flow from the first drain to the bulb, and wherein the second one-way valve provides one-way fluid flow from the second drain to the bulb.

16. The method of claim 13, further comprising adjusting a valve assembly to close fluid connection between the first tube and the bulb prior to applying and moving the pinching force on the second tube, and / or to close fluid connection between the second tube and the bulb prior to applying and moving the pinching force on the first tube.

17. The method of claim 13, wherein positioning the first and second drains includes positioning the first and second drains at different tissue site locations within the patient’s body.

18. The method of claim 13, further comprising draining fluid from the bulb into a fluid collection bag that is fluidly coupled to the bulb via a collection bag tube.

19. The method of claim 13, wherein at least one of the first and second drains includes a plurality of holes for efficiently collecting fluid from the patient’s body.

20. The method of claim 13, wherein the bulb includes a spring force modulator including one or more protrusions that protrude from an inner surface of the bulb and that limit an extent to which the bulb collapses inward upon manual compression of the bulb, thereby causing the bulb to maintain the negative pressure within a predetermined range as the bulb returns to an expanded state.

21. A medical drain system comprising: a bulb that is in fluid communication with a tube, wherein the tube is configured to couple to a drain positioned within a patient’s body, wherein the bulb is configured to- 36 -SG Docket No.: 14450-716.600generate sustained suction within the tube upon manual compression of the bulb, wherein bulb is configured to generate sufficient sustained suction to draw fluid from the patient’s body into the bulb for greater than 1 minute; a port in fluid communication with the tube, wherein the port is configured to allow application of a positive flushing fluid pressure and / or a negative pressure through the tube toward the drain; and a valve assembly configured to switch fluid access to the drain between the bulb and the port.

22. The medical drain system of claim 21, wherein the valve assembly includes a first on-off valve that is configured to open and close fluid access to the drain from the port, and a second on-off valve that is configured to open and close fluid access to the drain from the bulb.

23. The medical drain system of claim 21, wherein the valve assembly includes a switching valve that is configured to switch fluid access to the drain between the bulb and the port.

24. The medical drain system of claim 21, wherein the valve assembly is arranged close to the patient’s skin to minimize to reduce a chance of inflammatory or infective material entering a tissue space around the drain.

25. The medical drain system of claim 21, wherein the port is configured to allow flushing fluid to be injected into the tube toward the drain within the patient’s body.

26. The medical drain system of claim 21, wherein the port is configured to be connected to a vacuum source to apply suction within the tube and the drain within the patient’s body.

27. The medical drain system of claim 21, wherein the medical drain system includes multiple drains having corresponding multiple tubes, wherein the multiple drains are fluidly coupled with the bulb, wherein the valve assembly is further configured to: maintain the suction within the multiple tubes and the bulb upon movement of a pinching force applied along one or more of multiple tubes; and limit or prevent fluid from backflowing out of the bulb into the multiple tubes.

28. The medical drain system of claim 21, wherein the bulb includes a spring force modulator including one or more protrusions that protrude from an inner surface of the bulb and that limit an extent to which the bulb collapses inward upon manual compression of the bulb,- 37 -SG Docket No.: 14450-716.600thereby causing the bulb to maintain the suction within a predetermined range as the bulb returns to an expanded state.

29. A method of using a surgical drain system, the medical drain system comprising a drain including a tube that is fluidly coupled with a bulb, wherein the method comprises: adjusting a valve assembly that is configured to switch fluid access to the drain between the bulb and a port that is coupled to the tube, wherein adjusting the valve assembly comprises opening fluid access from the port to the drain and closing fluid access from the bulb to the drain; injecting a flushing fluid through the port to flush a tissue space around the drain; adjusting the valve assembly to open fluid access from the bulb to the drain and closing fluid access from the port to the drain; and drawing fluid from the drain in a patient’s body into the bulb.

30. The method of claim 29, further comprising applying negative pressure through the port to apply suction to the tissue space around the drain.

31. The method of claim 29, further comprising cycling between injecting the flushing fluid in the port and applying the negative pressure through the port to cycle a positive fluid pressure and the negative pressure to the tissue space around the drain.

32. The method of claim 29, further comprising manually compressing the bulb to generate a suction within the tube and the bulb, wherein the suction draws the fluid from the patient’s body into the bulb when the valve assembly opens fluid access from the bulb to the drain and closes fluid access from the port to the drain.

33. The method of claim 32, wherein the bulb includes a spring force modulator including one or more protrusions that protrude from an inner surface of the bulb and that limit an extent to which the bulb collapses inward upon manual compression of the bulb, thereby causing the bulb to maintain the suction within a predetermined range as the bulb returns to an expanded state.

34. The method of claim 29, wherein adjusting the valve assembly to open fluid access from the port to the drain and close fluid access from the bulb to the drain comprises: opening a first on-off valve to open fluid access from the port to the drain; and closing a second on-off valve to close fluid access from the bulb to the drain.- 38 -SG Docket No.: 14450-716.60035. The method of claim 29, wherein adjusting the valve assembly to open fluid access from the port to the drain and close fluid access from the bulb to the drain comprises adjusting a switching valve to open fluid access from the port to the drain and to close fluid access from the bulb to the drain.

36. The method of claim 29, further comprising arranging a position of the valve assembly close to the patient’ s skin to minimize to reduce a chance of inflammatory or infective material entering the tissue space around the drain.

37. The method of claim 29, wherein the medical drain system includes multiple drains having corresponding multiple tubes, wherein the multiple drains are fluidly coupled with the bulb, wherein the method further comprising dislodging material within at least one of the multiple tubes by moving a pinching force applied along the at least one of the multiple tubes in a direction toward the bulb, wherein a suction within at least one of the multiple tubes and the bulb is maintained while applying and moving the pinching force.

38. The method of claim 29, wherein one or more one-way valves limits or prevents fluid from backflowing out the bulb and into the tube.- 39 -SG Docket No.: 14450-716.600

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