Patent Description:
Dialysis is a treatment used to support a patient with insufficient renal function. The two principal dialysis methods are hemodialysis and peritoneal dialysis.

During hemodialysis ("HD"), the patient's blood is passed through a dialyzer of a dialysis machine while also passing a dialysis solution or dialysate through the dialyzer. A semi-permeable membrane in the dialyzer separates the blood from the dialysate within the dialyzer and allows diffusion and osmosis exchanges to take place between the dialysate and the blood stream. These exchanges across the membrane result in the removal of waste products, including solutes like urea and creatinine, from the blood. These exchanges also regulate the levels of other substances, such as sodium and water, in the blood. In this way, the dialysis machine acts as an artificial kidney for cleansing the blood.

During peritoneal dialysis ("PD"), a patient's peritoneal cavity is periodically infused with dialysis solution or dialysate. The membranous lining of the patient's peritoneum acts as a natural semi-permeable membrane that allows diffusion and osmosis exchanges to take place between the solution and the blood stream. These exchanges across the patient's peritoneum, like the continuous exchange across the dialyzer in HD, result in the removal of waste products, including solutes like urea and creatinine, from the blood, and regulate the levels of other substances, such as sodium and water, in the blood.

Automated PD machines called PD cyclers are designed to control the entire PD process so that it can be performed at home, usually overnight without clinical staff in attendance. This process is termed continuous cycler-assisted PD (CCPD). Many PD machines are designed to automatically infuse, dwell, and drain dialysate to and from the patient's peritoneal cavity. The treatment typically lasts for several hours, often beginning with an initial drain procedure to empty the peritoneal cavity of used or spent dialysate. The sequence then proceeds through the succession of fill, dwell, and drain phases that follow one after the other. Each phase is called a cycle.

<CIT> describes a body-implantable catheter which can be employed for peritoneal dialysis and the like includes a flexible, elongated, perforated tube, together with means for urging at least a portion of the tube into a tightly wound cylindrical helix configuration.

<CIT> describes a method is provided for detecting leaks in a disposable medical fluid cassette that includes a base and a flexible membrane attached to the base.

<CIT> describes a surgical system is provided with an irrigation line and an aspiration line wherein the irrigation line is adapted to exhibit a higher compliance or reduced stiffness relative to the aspiration line.

<CIT> describes a surgical drain that includes reinforced tubing.

<CIT> describes a tube adapted to convey fluids under pressure and to be distorted without kinking and blocking of fluid flow therethrough. The tube has a resinous core tubing provided with internal longitudinal ribs. The tube is provided with a fibrous reinforcing member disposed about the core tube and an outer sheath.

<CIT> describes a protector that is used by being attached to a puncture device. The protector includes an outer tube and an inner tube. The outer tube includes an outer tube main body including an outer tube lumen for housing the puncture device, a holding part for holding a hub, and an extended part extended from the holding part in a proximal end direction. By moving the inner tube in a distal end direction, the inner surface of the lumen inclined part is abutted against the extended part, and the extended part is biased by the lumen inclined part in a direction in which a diameter of the tube is reduced.

<CIT> describes a control clamp for adjusting the flow rate of a liquid through a flexible hose with a manually operable means for varying the flow cross section of the hose.

In one aspect, the claims are directed to medical tubing system that includes a medical fluid cassette and a tube closure device.

The medical fluid cassette may optionally include one or more of the following features. The internal ribs of the tube may have triangular cross-sectional shapes. The tube may include three of the internal ribs. The internal ribs may have heights in a range of <NUM> percent to <NUM> percent of an inner radius of the tube. Apices of the triangular cross-sectional shapes may point toward the central longitudinal axis at a geometric center of a cross-section of the tube. The medical fluid cassette may be a peritoneal dialysis fluid cassette. The tube may be a patient line attached to the peritoneal dialysis fluid cassette. The tube may have a durometer of shore <NUM>.

The a medical tubing system may optionally include one or more of the following features. The clamp collar may be longitudinally movable in relation to the set of jaws between: (i) a first position in which the set of jaws are in an open configuration and (ii) a second position in which the clamp collar deflects the set of jaws radially inward in comparison to the open configuration. Each jaw of the set of jaws may include a ramp surface that slidingly mates against a corresponding annular ramp surface of the clamp collar. The clamp collar may be threadedly mated to the sleeve. The clamp collar may include an internal thread that threadedly mates with an external thread of the sleeve. Each jaw of the set of jaws may be radially alignable with a respective internal rib of the tube while the tube closure device is positioned on the tube. The tube may include three internal ribs, and the set of jaws may include three jaws. The tube may define longitudinal grooves extending along an outer surface of the tube that are radially aligned with the internal ribs.

A kink and compression tolerant medical tube may define a central longitudinal axis and includes internal ribs extending inwardly from an inner wall of the tube toward the central longitudinal axis. The tube has a durometer in a range of shore <NUM> to shore <NUM>.

Such a kink and compression tolerant medical tube may optionally include one or more of the following features. The internal ribs may have triangular cross-sectional shapes. Apices of the triangular cross-sectional shapes may point toward the central longitudinal axis at a geometric center of a cross-section of the tube. The tube may include three of the internal ribs. The internal ribs may have heights in a range of <NUM> percent to <NUM> percent of an inner radius of the tube. The internal ribs may spiral around the central longitudinal axis.

Implementations can include one or more of the following advantages.

In certain implementations, the tubing and systems described herein can enhance the efficacy of patient medical treatments because the tubing resists occlusion due to kinking and/or compression. That is, even though the tubing may become kinked or compressed, the tubing will continue to have an open lumen to allow for fluid flow. Accordingly, medical treatments can take place with fewer treatment interruptions, fewer alarms, and faster cycle times.

In some implementations, patient safety is improved because even while the tubing is kinked or crushed, some flow through the tubing will continue and the medical treatment will proceed. Moreover, the tubing described herein can be kink and compression tolerant while maintaining a desirable level of flexibility or compliance. Such flexible kink and compression tolerant tubing mitigates the potential for inducing stress to the patient's tissue from lateral forces on a catheter that may otherwise occur from stiffer types of kink and compression tolerant tubing.

In certain implementations, the patient's experience and comfort is improved using the kink and compression tolerant tubing and systems described herein. Even though the tubing is kink and compression tolerant, it is also compliant in bending, resulting in enhanced patient comfort in comparison to stiffer tubing. Additionally, treatment system alarms due to tubing occlusions may be reduced using the kink and compression tolerant tubing and systems described herein. As such, the patient may experience more relaxation during treatment, and get better sleep in some cases.

In certain implementations, when blood is being transported using the kink and compression tolerant tubing described herein, the tubing will tend to reduce the potential for inducement of hemolysis. The reduced potential for hemolysis results because, even though the tubing may become kinked or compressed, the tubing will continue to have an open lumen to allow for the blood to flow.

This disclosure relates generally to tubing that can be used in association with medical fluid pumping systems (e.g., PD systems, hemodialysis systems, hemofiltration systems, hemodiafiltration systems, etc.) and other medical devices/systems. In some examples, the tubing described herein is used in conjunction with, or as a part of, a medical fluid cassette that interfaces with such medical fluid pumping systems. In some cases the tubing described herein may be connected to a patient via a catheter, and may be used to convey fluids such as, but not limited to, dialysis solution (or "dialysate"), spent dialysate (or "effluent"), blood, saline, medications, water, ionized water, air, oxygen, other gasses, and so on. Such fluids may be conveyed to the patient from the medical system, or from the patient to the medical system or elsewhere.

As described further below, the tubing described herein is designed and configured to be advantageously tolerant of kinking and/or crushing. That is, even if the tubing is kinked or compressed (or "crushed"), at least some portion of the lumen defined by the tubing will remain open and some fluid will continue to flow through the tubing.

The kink and compression tolerant tubing is described below using the example context of a PD system. It should be understood, however, that a PD system is merely one of the contexts in which the kink and compression tolerant tubing described herein can be beneficially used.

Referring to <FIG> and <FIG>, an example PD system <NUM> includes a PD cycler (also referred to as a PD machine) <NUM> seated on a cart <NUM>. The PD cycler <NUM> includes a housing <NUM>, a door <NUM>, and a cassette interface <NUM> that abuts a disposable PD cassette <NUM> when the cassette <NUM> is disposed within a cassette compartment <NUM> formed between the cassette interface <NUM> and the closed door <NUM>. A heater tray <NUM> is positioned on top of the housing <NUM>. The heater tray <NUM> is sized and shaped to accommodate a bag of dialysis solution (e.g., a five liter bag of dialysis solution). The PD cycler <NUM> also includes a touch screen <NUM> and additional control buttons <NUM> that can be operated by a user (e.g., a patient) to allow, for example, set-up, initiation, and/or termination of a PD treatment.

Dialysis solution bags <NUM> are suspended from fingers on the sides of the cart <NUM>, and a heater bag <NUM> is positioned on the heater tray <NUM>. The dialysis solution bags <NUM> and the heater bag <NUM> are connected to the cassette <NUM> via dialysis solution bag lines <NUM> and a heater bag line <NUM>, respectively. The dialysis solution bag lines <NUM> can be used to pass dialysis solution from dialysis solution bags <NUM> to the cassette <NUM> during use, and the heater bag line <NUM> can be used to pass dialysis solution back and forth between the cassette <NUM> and the heater bag <NUM> during use. In addition, a patient line <NUM> and a drain line <NUM> are connected to the cassette <NUM>. The patient line <NUM> can be connected to a patient's abdomen via a catheter, and can be used to pass dialysis solution back and forth between the cassette <NUM> and the patient during use. The drain line <NUM> can be connected to a drain or drain receptacle and can be used to pass dialysis solution from the cassette <NUM> to the drain or drain receptacle during use. The spent dialysate is also referred to as effluent herein.

The cassette <NUM> generally includes a rigid plastic molded base member and a flexible membrane attached to the base. The base and the membrane of the cassette <NUM> cooperate to define various dialysis solution channels and dialysis solution chambers integrally within the cassette <NUM>. The cassette <NUM> is configured to align with various valve actuators, sensors and other components of the PD cycler <NUM> when the cassette <NUM> is coupled with the PD cycler <NUM>. The cassette <NUM> can be a single-use disposable element used for a PD treatment.

<FIG> shows a more detailed view of the cassette interface <NUM> and the door <NUM> of the PD cycler <NUM>. As shown, the PD cycler <NUM> includes pistons 133A, 133B with piston heads 134A, 134B that can be axially moved within piston access ports 136A, 136B formed in the cassette interface <NUM>. The pistons 133A, 133B include shafts that are connected to motors that can be operated to move the piston heads 134A, 134B axially inward and outward within the piston access ports 136A, 136B. When the cassette <NUM> is positioned within the cassette compartment <NUM> of the PD cycler <NUM> with the door <NUM> closed, the piston heads 134A, 134B of the PD cycler <NUM> align with pump chambers 138A, 138B of the cassette <NUM> such that the piston heads 134A, 134B can be mechanically connected to fastening members of the cassette <NUM> overlying the pump chambers 138A, 138B. As a result of this arrangement, movement of the piston heads 134A, 134B toward the cassette <NUM> during treatment can decrease the volume of the pump chambers 138A, 138B, and force dialysis solution out of the pump chambers 138A, 138B, while retraction of the piston heads 134A, 134B away from the cassette <NUM> can increase the volume of the pump chambers 138A, 138B and cause dialysis solution to be drawn into the pump chambers 138A, 138B.

Still referring to <FIG> and <FIG>, during PD treatment, the patient line <NUM> extending from the cassette <NUM> is connected to a patient's abdomen via a catheter, and the drain line <NUM> is connected to a drain or drain receptacle. The PD treatment typically begins by emptying the patient of spent dialysis solution that remains in the patient's abdomen from the previous treatment. To do this, the pump of the PD cycler <NUM> is activated to cause the pistons 133A, 133B to reciprocate to cause the spent dialysis solution to be drawn from the patient into the patient line <NUM>, and then to the fluid pump chambers 138A, 138B of the cassette <NUM>. The spent dialysis solution is then pumped from the fluid pump chambers 138A, 138B to the drain via the drain line <NUM>.

After draining the spent dialysis solution from the patient, heated dialysis solution is transferred from the heater bag <NUM>, through the cassette <NUM>, and to the patient via the patient line <NUM>. To do this, the motor or motors of the PD cycler <NUM> is/are activated to cause the pistons 133A, 133B to reciprocate and certain inflatable members <NUM> of the PD cycler <NUM> are inflated to cause the warmed dialysis solution to be drawn into the fluid pump chambers 138A, 138B of the cassette <NUM> from the heater bag <NUM> via the heater bag line <NUM>. The warmed dialysis solution is then pumped from the fluid pump chambers 138A, 138B to the patient via the patient line <NUM>.

Once the dialysis solution has been pumped from the heater bag <NUM> to the patient, the dialysis solution is allowed to dwell within the patient for a period of time. During this dwell period, toxins cross the peritoneum of the patient into the dialysis solution from the patient's blood. As the dialysis solution dwells within the patient, the PD cycler <NUM> prepares fresh dialysate for delivery to the patient in a subsequent cycle. In particular, the PD cycler <NUM> pumps fresh dialysis solution from one of the four full dialysis solution bags <NUM> into the heater bag <NUM> for heating. To do this, the pump of the PD cycler <NUM> is activated to cause the pistons 133A, 133B to reciprocate and certain inflatable members <NUM> of the PD cycler <NUM> are inflated to cause the dialysis solution to be drawn into the fluid pump chambers 138A, 138B of the cassette <NUM> from the selected dialysis solution bag <NUM> via its associated line <NUM>. The dialysis solution is then pumped from the fluid pump chambers 138A, 138B to the heater bag <NUM> via the heater bag line <NUM>.

After the dialysis solution has dwelled within the patient for the desired period of time, the spent dialysis solution is pumped from the patient through the patient line <NUM>, and then to the drain via drain line <NUM>. The heated dialysis solution is then pumped from the heater bag <NUM> and through the patient line <NUM> to the patient where it dwells for a desired period of time. These steps are repeated with the dialysis solution from two of the three remaining dialysis solution bags <NUM>. The dialysis solution from the last dialysis solution bag <NUM> is typically delivered to the patient via the patient line <NUM> and left in the patient until the subsequent PD treatment.

PD treatments (e.g., as described above) usually occur at night while the patient is sleeping. APD treatment typically involves several fills and drains of many liters of dialysate fluid, and may occur over the entire night. In some circumstances, the patient line <NUM> (connected to the patient) may inadvertently become obstructed to fluid flow because of unintentional kinking or pinching (crushing) of the patient line <NUM> tubing. For example, the patient may simply roll over while sleeping, causing the patient line <NUM> to become partially or fully kinked or crushed. In that case, the PD treatment can be partially or fully inhibited, disrupted, and/or discontinued.

Most PD systems have one or more pressure sensors to monitor the fluid pressure in the patient line <NUM>. Those pressure sensors can detect when the patient line <NUM> has become obstructed because of being partially or fully kinked or crushed. In such a case, the PD system (e.g., the PD cycler <NUM>) may pause the treatment and deliver an alert/alarm in attempt to wake the patient. An awakened patient will then need to check for kinks and/or compression of the patient line <NUM>, resolve the problem, and then resume treatment. Unfortunately for the patient, this scenario may repeat itself many times during a night.

One potential way to mitigate the problem of the patient line <NUM> becoming obstructed because of kinking or crushing is to make the patient line <NUM> stiff so that it is very resistant to bending and compression. In some cases, metal wires are embedded in the wall of tubing for such purposes. However, if the tubing used for the patient line <NUM> is made very stiff (resistant to bending and compression), then the tubing tends to be very uncomfortable for the patient to use. For example, when the patient rolls over during sleep, the stiff tube used for the patient line <NUM> will likely cause substantial stress and pain to the patient via lateral forces exerted by the catheter to the patient.

Accordingly, making the patient line <NUM> flexible while also tolerant to kinking and crushing will provide a more effective PD treatment (e.g., with less interruptions), and a better patient experience (e.g., with fewer alarms and fewer required interventions). That is, tubing that is flexible and that will allow for flow through the tubing even while kinked or crushed will provide many benefits when used as the patient line <NUM> for the PD system <NUM> (and for other medical uses).

Referring to <FIG>, a portion of an example kink and compression tolerant medical tubing <NUM> (or simply "tubing <NUM>") is illustrated. <FIG> shows a cross-sectional shape of the tubing <NUM>. As described further below, the kink and compression tolerant medical tubing <NUM> can be advantageously used as the patient line <NUM> (<FIG> and <FIG>), for example.

The tubing <NUM> can be made from any suitable polymeric material, such as polyvinyl chloride (PVC). In some embodiments, the PVC material has a durometer of shore <NUM>. In some embodiments, the durometer of the PVC material is in a range of shore <NUM> to shore <NUM>, or shore <NUM> to shore <NUM>, or shore <NUM> to shore <NUM>. The tubing <NUM> is preferably sufficiently flexible and compliant so that movements of the patient that result in bending of the tubing <NUM> do not induce stress at the location where the tubing <NUM> is percutaneously attached to the patient (e.g., via a catheter). In the depicted embodiment, there is no reinforcing wire/material within the wall of the tubing <NUM>.

The tubing <NUM> is scalable to any suitable size. In one example embodiment the outer diameter of the tubing <NUM> is <NUM> and the inner diameter of the tubing <NUM> is <NUM> (hence, the inner radius <NUM> is <NUM>). The tubing <NUM> can be made to have any suitable length.

The tubing <NUM> defines a single lumen <NUM> through which fluid can flow. The lumen <NUM> is the open space within the tubing <NUM>. The tubing <NUM> includes three internal ribs <NUM>10a, 310b, and 310c (or collectively "ribs <NUM>10a-c"). In the depicted embodiment, the ribs 310a-c are triangular projections that extend inward from the inner wall of the tubing. Each of the triangular ribs <NUM>10a-c includes an apex, and the ribs 310a-c are arranged such that the apices are pointed towards a geometric center <NUM> of the tubing <NUM>. The triangular ribs <NUM>10a-c are arranged at about <NUM> degrees relative to each other around the <NUM> degree inner circumference of the tubing <NUM>. A central longitudinal axis of the tubing <NUM> extends along the geometric center <NUM>.

In the depicted embodiment, the ribs <NUM>10a-c and the wall of the tubing <NUM> are contiguous and made of the same material (e.g., by extrusion). The lumen <NUM> is the open space within the tubing <NUM> (and does not include the area of the ribs <NUM>10a-c).

Each of the ribs <NUM>10a-c extends inward from the inner wall of the tubing <NUM> for a distance that is referred to as the rib height <NUM>. The rib height <NUM> is less than the inner radius <NUM>. As described further below, the inventors have discovered that when the rib height <NUM> is <NUM>% of the inner radius <NUM>, the size of the lumen <NUM> is maximized while the tubing <NUM> is fully compressed.

<FIG> depicts the tubing <NUM> in four differing states of lateral compression. This type of compression to the tubing <NUM> may be induced, for example, by kinking (bending), by pure lateral compression (crushing), or by a combination of both. In <FIG>, the tubing <NUM> is not compressed or deformed. In <FIG>, the tubing <NUM> is considered to be fully compressed (e.g., the apex of each of the three ribs 310a-c is in contact with the inner wall of the tubing <NUM>). <FIG> depict successive degrees of compression between <FIG>.

It can be seen that the cross-section of the lumen <NUM> is shaped differently in each of the depicted differing states of compression. Actually, the lumen <NUM> is divided up into multiple separated portions while the tubing <NUM> is in the fully compressed state (shown in <FIG>). In this particular example, the lumen <NUM> is divided up into four separated open area portions while the tubing <NUM> is in the fully compressed state.

The tubing <NUM> is kink and compression tolerant because, as <FIG> illustrates, even though the tubing <NUM> is fully compressed there is/are still open area(s) (the lumen <NUM>) that allows fluid to flow through the tubing <NUM>. As stated above, the inventors have discovered that when the rib height <NUM> is <NUM>% of the inner radius <NUM>, the open area of the lumen <NUM> is maximized while the tubing <NUM> is fully compressed.

Referring to <FIG>, cross-sections often differing designs of tubing 400a, 400b, 400c, 400d, 400e, 400f, <NUM>, <NUM>, 400i, and 400j (or collectively tubing 400a-j) are each illustrated in uncompressed and fully compressed states. The tubing 400a-j differ from each other with respect to an individual tubing's rib height as a percentage of its inner radius. For example, tubing 400a has no ribs; the height of the ribs of the tubing 400b are each <NUM>% of the inner radius of tubing 400b; the height of the ribs of the tubing 400c are each <NUM>% of the inner radius of tubing 400c; the height of the ribs of the tubing 400d are each <NUM>% of the inner radius of tubing 400d; the height of the ribs of the tubing 400e are each <NUM>% of the inner radius of tubing 400e; the height of the ribs of the tubing 400f are each <NUM>% of the inner radius of tubing 400f; the height of the ribs of the tubing <NUM> are each <NUM>% of the inner radius of tubing <NUM>; the height of the ribs of the tubing <NUM> are each <NUM>% of the inner radius of tubing <NUM>; the height of the ribs of the tubing 400i are each <NUM>% of the inner radius of tubing 400i; and the height of the ribs of the tubing 400j are each <NUM>% of the inner radius of tubing 400j.

In order to investigate and discover the optimal rib height for kink and compression tolerance, the inventors created a solid model of each design of the tubing 400a-j. Then, using finite element analysis (FEA), the fully compressed state for each design of the tubing 400a-j was simulated (as shown). From there, the fully compressed open area of each design of the tubing 400a-j was calculated.

Referring also to <FIG>, the results of the calculations of the fully compressed open areas of each design of the tubing 400a-j are shown in a graph <NUM>. That is, the graph <NUM> is a plot of the fully compressed open area of each design of the tubing 400a-j as a function of each tubing's rib height as a percentage of its inner radius. The individual open area value for each design of the tubing 400a-j is shown, and a fit line <NUM> is also shown.

The graph <NUM> shows that the tubing 400f yields the greatest amount of open area when fully compressed. The ribs of the tubing 400f are each <NUM>% of the inner radius of tubing 400f. The open area of the tubing 400f while it is in the fully compressed state is about <NUM>% of the uncompressed open area of the tubing 400f. The fit line <NUM> shows that the open area while fully compressed is effectively optimal in a range of about <NUM>% to about <NUM>% in terms of rib height as a percentage of inner radius.

The inventors also experimented with the kink and compression tolerance effects of various numbers of ribs in the tubing. For example, the inventors experimented with zero ribs, two ribs, three ribs, four ribs, five ribs, six ribs, and seven ribs. The results of such experiments demonstrated that the three rib design was superior than the others.

Referring to <FIG>, while the tubing described herein includes internal ribs that advantageously provide kink and compression tolerance (e.g., the tubing will continue to have open luminal area even when fully compressed in the manner described above), in some cases it is desirable or necessary to fully close the lumen of such tubing. Accordingly, a collet-like tube closure device <NUM> can be used to fully close internally ribbed tubing <NUM> (tubing <NUM> is internally the same as the tubing <NUM> and tubing 400f described above). In <FIG>, the internally ribbed tubing <NUM> is illustrated as fully open, and in <FIG> the internally ribbed tubing <NUM> is illustrated as fully closed because the tube closure device <NUM> is acting on the tubing <NUM>.

Referring also to <FIG>, the collet-like tube closure device <NUM> includes an externally threaded sleeve <NUM> and an internally threaded clamp collar <NUM>. The externally threaded sleeve <NUM> and the internally threaded clamp collar <NUM> are threadedly coupled together. Accordingly, when the internally threaded clamp collar <NUM> is rotated in relation to the externally threaded sleeve <NUM> the internally threaded clamp collar <NUM> will move longitudinally in relation to the externally threaded sleeve <NUM>. For example, while in <FIG> the externally threaded sleeve <NUM> and the internally threaded clamp collar <NUM> are essentially abutting against each other, in <FIG> there is a gap <NUM> between the externally threaded sleeve <NUM> and the internally threaded clamp collar <NUM>.

The externally threaded sleeve <NUM> defines an opening that slidingly receives the tubing <NUM>. Three jaws 712a, 712b, and 712c are connected to and extend longitudinally from the externally threaded sleeve <NUM> like cantilevered beams. The jaws 712a, 712b, and 712c are radially deflectable in relation to the externally threaded sleeve <NUM>.

Each of the three jaws 712a, 712b, and 712c includes a respective ramp surface 714a, 714b, and 714c. The internally threaded clamp collar <NUM> includes a corresponding annular ramp surface <NUM> that slidingly mates against the ramp surfaces 714a, 714b, and 714c.

The internally threaded clamp collar <NUM> can be threadedly adjusted in relation to the externally threaded sleeve <NUM> such that the ramp surface <NUM> adjustably exerts pressure on each of the three jaws 712a, 712b, and 712c to force the jaws 712a, 712b, and 712c radially inward. For example, in <FIG> the three jaws 712a, 712b, and 712c are depicted as being forced radially inward by the internally threaded clamp collar <NUM>, whereas in <FIG> the three jaws 712a, 712b, and 712c are depicted as radially positioned such that the tubing <NUM> is uncompressed (because the internally threaded clamp collar <NUM> is not pressing the three jaws 712a, 712b, and 712c radially inward).

In the depicted embodiment, the tubing <NUM> defines three longitudinally-extending grooves 612a, 612b, and 612c extending along the outer surface of the tubing <NUM>. The three longitudinally-extending grooves 612a, 612b, and 612c are in radial alignment with the three internal ribs of the tubing <NUM> (see e.g., the example internal ribs 310a, 310b, and 310c of tubing <NUM> as shown in <FIG>).

The three jaws 712a, 712b, and 712c are matingly positioned within the three longitudinally-extending grooves 612a, 612b, and 612c. That is, the jaw 712a is positioned within the groove 612a, the jaw 712b is positioned within the groove 612b, and the jaw 712c is positioned within the groove 612c. When the externally threaded sleeve <NUM> is slid longitudinally along the tubing <NUM>, the three jaws 712a, 712b, and 712c slide within the three longitudinally-extending grooves 612a, 612b, and 612c.

Because the three longitudinally-extending grooves 612a, 612b, and 612c are in radial alignment with the three internal ribs of the tubing <NUM>, and because the three jaws 712a, 712b, and 712c are positioned within the three longitudinally-extending grooves 612a, 612b, and 612c, it follows that the three jaws 712a, 712b, and 712c are in radially alignment with the three internal ribs of the tubing <NUM>. Accordingly, when the three jaws 712a, 712b, and 712c are forced radially inward by the internally threaded clamp collar <NUM>, the three internal ribs of the tubing <NUM> are forced toward the center of the tubing <NUM>. The apices of the three internal ribs of the tubing <NUM> meet each other at the center of the tubing <NUM>. As a result the tubing <NUM> becomes fully closed (there is no open portion of the lumen of the tubing <NUM>).

Again, in the arrangement of <FIG> the internally threaded clamp collar <NUM> is positioned in relation to the three jaws 712a, 712b, and 712c such that the ramp surface <NUM> of the internally threaded clamp collar <NUM> is not exerting sufficient pressure on the ramp surfaces 714a, 714b, and 714c of the three jaws 712a, 712b, and 712c to cause the jaws 712a, 712b, and 712c to compress the tubing <NUM>. Then, in order to begin to close the tubing <NUM>, a user can twist the internally threaded clamp collar <NUM> in relation to the externally threaded sleeve <NUM>. In doing so, the internally threaded clamp collar <NUM> will move longitudinally away from the externally threaded sleeve <NUM> and the ramp surface <NUM> of the internally threaded clamp collar <NUM> will begin to exert pressure on the ramp surfaces 714a, 714b, and 714c of the three jaws 712a, 712b, and 712c to cause the jaws 712a, 712b, and 712c to compress the tubing <NUM>. If so desired, the user can continue twisting the internally threaded clamp collar <NUM> in relation to the externally threaded sleeve <NUM> until the ramp surface <NUM> of the internally threaded clamp collar <NUM> exerts sufficient pressure on the ramp surfaces 714a, 714b, and 714c of the three jaws 712a, 712b, and 712c to cause the jaws 712a, 712b, and 712c to fully close the tubing <NUM> by causing the three internal ribs of the tubing <NUM> meet each other at the center of the tubing <NUM> (as depicted in <FIG>).

A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the scope of the invention. For example, <FIG> illustrates another example kink and compression tolerant medical tubing <NUM>. As with the tubing <NUM> described above, the tubing <NUM> includes three ribs 810a, 810b, and 810c. In a manner that is analogous to the tubing <NUM>, the ribs 810a-c can be triangular and can have, for example, a rib height that is <NUM>% of the inner radius of the tubing <NUM>. However, whereas the ribs 310a, 310b, and 310c of the tubing <NUM> extend parallel to the longitudinal axis of the tubing <NUM>, the ribs 810a, 810b, and 810c spiral around the longitudinal axis of the tubing <NUM>. In some embodiments, the ribs 810a, 810b, and 810c extend helically around the longitudinal axis of the tubing <NUM>. The angle that the ribs 810a, 810b, and 810c extend in relation to the longitudinal axis of the tubing <NUM> can be in a range between <NUM> degrees to <NUM> degrees, or between <NUM> degrees to <NUM> degrees, or between <NUM> degrees to <NUM> degrees, or between <NUM> degrees to <NUM> degrees, or between <NUM> degrees to <NUM> degrees, or between <NUM> degrees to <NUM> degrees, or between <NUM> degrees to <NUM> degrees, or more than <NUM> degrees. This tubing design with spirally extending internal ribs 810a, 810b, and 810c can advantageously provide consistent bending/flexure properties regardless of the bend direction relative to the tubing <NUM>.

While the tubing <NUM> has been described as being made from PVC, in some embodiments, the tubing <NUM> can be made from any other suitable polymeric material such as, but not limited to, polyethylene, polyurethanes, nylons, fluoropolymers, natural rubber, natural rubber latex, synthetic rubber, thermoplastic rubbers, silicone, and the like, and combinations thereof.

While the tubing <NUM> has been described as having an outer diameter of <NUM>, in some embodiments, the tubing <NUM> has an outer diameter in a range of <NUM> to <NUM>, or <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, and/or more than <NUM>. While the tubing <NUM> have been described as having an inner diameter of <NUM>, in some embodiments, the tubing <NUM> has an inner diameter in a range of <NUM> to <NUM>, or <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, and/or more than <NUM>.

While in the depicted embodiment of the tubing <NUM> there is no reinforcing wire/material within the wall of the tubing <NUM>, in some embodiments, one or more wires or other types of reinforcing materials can be included within the wall of the tubing <NUM>.

While the depicted embodiment of the tubing <NUM> includes three internal ribs 310a-c, in some embodiments, one, two, four, five, six, seven, or more than seven ribs are included.

While the depicted embodiment of the tubing <NUM> the rib height <NUM> is <NUM>% of the radius <NUM> of the tubing <NUM>, in some embodiments, the rib height <NUM> is in a range of <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or <NUM>% to <NUM>%, or <NUM>% to <NUM>% of the radius <NUM> of the tubing <NUM>.

While the ribs 310a-c have been described as triangular shaped, in some embodiments, other shapes as used such as, but not limited to, rectangular, ovular, and so on. While in the depicted embodiment the ribs <NUM>10a-c are solid, in some embodiments, the ribs 310a-c are hollow (have open space within the boundaries of the ribs 310a-c).

While the PD system <NUM> has been described and illustrated as including piston pumps, in some embodiments, a PD system that is otherwise similar in construction and function to the PD system <NUM> may include one or more peristaltic pumps instead of piston pumps. <FIG>, for example, illustrates a PD system <NUM> including a cycler <NUM> and a cartridge <NUM> (e.g., a liquid distribution system) that, when connected to the cycler <NUM>, forms a peristaltic pump.

The cartridge <NUM> includes a pumping element <NUM>, a first hub chamber <NUM>, and a second hub chamber <NUM>. The first chamber <NUM> includes a pump inlet <NUM> that can be connected to the pumping element <NUM> via a pump enter line, a liquid supply port <NUM> with a valve that can be connected to a liquid supply container via a liquid supply line, and a patient port <NUM> with a valve that can be connected to a patient via a patient line <NUM>. In some embodiments, the patient line <NUM> can be kink and compression tolerant tubing (e.g., like the tubing <NUM> described above in reference to <FIG>, and/or like the tubing <NUM> described above in reference to <FIG>, and/or like the tubing <NUM> described above in reference to <FIG>). The second hub chamber <NUM> includes a pump outlet <NUM> that can be connected to the pumping element <NUM> via a pump exit line, a drain port <NUM> with a valve that can be connected to a drain collector via a drain line along which a chemical testing device <NUM> positioned (e.g. as shown in <FIG>), and a patient port <NUM> with a valve that can be connected to a patient <NUM> via the patient line <NUM>.

The cartridge <NUM> further forms a cavity <NUM>, which forms part of a pressure sensor. The first hub chamber <NUM> has three liquid supply ports <NUM>, one patient port <NUM>, one pump inlet <NUM>, and a cavity <NUM> that forms part of a pressure sensor. The second hub chamber <NUM> has a patient port <NUM>, a drain port <NUM>, and a pump outlet <NUM>. The cartridge <NUM> also includes a warmer chamber <NUM>, which includes a warmer port <NUM> and a patient port <NUM>. The warmer port <NUM> is connected to a warmer <NUM> (shown in <FIG>) via a warmer tube connector <NUM> and a warmer exit line <NUM>. The patient port <NUM> is connected to the patient line <NUM>. The second hub chamber <NUM> includes a warmer port <NUM> connected to a warmer <NUM> via a warmer tube connector <NUM> and a warmer enter line <NUM>.

The pumping element <NUM> includes a pump casing <NUM>, which contains three rollers <NUM> maintained around a center of the pump casing <NUM> by a roller separator <NUM>. The space between the roller separator <NUM> and the pump casing <NUM> defines a pump race <NUM> in which a flexible tube <NUM> is disposed. The flexible tube <NUM> is connected to the pump enter line <NUM> and the pump exit <NUM> line. The rollers <NUM> may be motor driven by a shaft <NUM> (shown in <FIG>) in such a way as to progressively compress the flexible tube <NUM>, thereby resulting in a peristaltic movement of fluid contained within and along the flexible tube <NUM>. Accordingly, the pump casing <NUM>, the rollers <NUM>, the roller separator <NUM>, and the pump race <NUM> together form a peristaltic pump by which liquid (e.g., dialysate) can be moved through the PD system <NUM>.

<FIG> shows an assembly including the cartridge <NUM>, a patient line <NUM>, supply bags <NUM>, a warmer enter line <NUM>, a warmer outer line <NUM>, a warmer pouch <NUM> to be put into contact with a warming plate, a drain line <NUM>, and the chemical testing device <NUM> installed to the drain line <NUM>. In some embodiments, the patient line <NUM> can be kink and compression tolerant tubing (such as the tubing <NUM> described above in reference to <FIG>, the tubing <NUM> described above in reference to <FIG>, or the tubing <NUM> described above in reference to <FIG>).

<FIG> shows the cycler <NUM> with the slot <NUM> and the cartridge <NUM> omitted to illustrate various internal features of the cycler <NUM>. The cycler <NUM> includes a driving zone, which includes a several actuators <NUM> and a motor shaft <NUM> for interfacing with the rollers <NUM>. The cycler <NUM> also includes an air sensor <NUM> situated close to the patient line <NUM> when the cartridge <NUM> is inserted. <FIG> shows the cycler <NUM> with the insertion slot <NUM> in an open configuration and with the cartridge <NUM> disposed within the insertion slot <NUM>, while <FIG> shows the cycler <NUM> with the insertion slot <NUM> in a closed configuration and with the cartridge <NUM> disposed within the insertion slot <NUM>.

Claim 1:
A medical tubing system comprising:
a medical fluid cassette (<NUM>) comprising
a base member,
a flexible membrane attached to the base member such that the membrane and the base member cooperate to define one or more fluid flow paths within the medical fluid cassette, and
a tube (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) extending from the medical fluid cassette and in fluid communication with the one or more fluid flow paths, the tube defining a central longitudinal axis at a geometric center (<NUM>) of a cross-section of the tube,
characterised by the tube
including internal ribs (<NUM>, <NUM>) extending inwardly from an inner wall of the tube toward the central longitudinal axis at the geometric center (<NUM>) of the cross-section of the tube; and
a tube closure device (<NUM>) comprising
a sleeve (<NUM>) defining an opening that slidingly receives the tube,
a set of jaws (<NUM>) coupled to the sleeve and radially deflectable in relation to the sleeve, and
a clamp collar (<NUM>) positioned around at least portions of set of jaws and longitudinally movable in relation to the set of jaws.