Patent Description:
Generally, hollow fiber blood oxygenators that are used to exchange oxygen (O2) and carbon dioxide (CO2) in extracorporeal circulation during cardiac surgery have one of two forms. Either the oxygenator has a cylindrical housing with a crisscross hollow fiber mat spirally wound around a cylindrical central core, or the oxygenator has a polygonal housing with stacked (piled) hollow fiber mat layers. Blood flows outside the hollow fiber lumens and oxygenating gases flow inside the hollow fiber lumens.

In cylindrically wound oxygenators, blood flow across the hollow fibers may be radial, longitudinal, circumferential, or a combination of two or more of these. Often, this leads to a blood flow path that is relatively long and non-laminar to guarantee high gas exchange efficiency with reduced surface area and limited device priming volume, which are important parameters for optimal patient perfusion. If the blood path is too long, the resulting pre-oxygenator to post-oxygenator pressure gradient may be elevated, causing excessive mechanical stress and possible damage to blood cells. Also, at times, the pressure gradient may become so high that it is not possible to reach a desired extracorporeal blood flow rate, especially if the heart lung machine (HLM) pump, used to force blood through the extracorporeal circuit, is of the centrifugal (nonocclusive) type. Such situations may lead the perfusionist, i.e., the HLM specialist, to change out the oxygenator during operation, which is a traumatic event putting the patient at risk, as circulation needs to be momentarily interrupted. Moreover, from a manufacturing point of view, a wound oxygenator is potted with potting material (resin) at both extremities to hermetically seal and separate the blood from the gases. This potting is often done in two or more steps, which adds complexity and cost to manufacturing the oxygenator.

In stacked hollow fiber mat layer oxygenators, blood flows outside the hollow fibers in a direction that is transverse to the stacked hollow fiber mat layers. Typically, this leads to shorter blood flow paths than in the cylindrically wound oxygenator and the resulting pre-oxygenator to post-oxygenator blood pressure gradient is lower such that mechanical damage to blood cells is reduced. However, an inconvenience derives from the housing shape which is generally polygonal, requiring the potting to be polygonal and characterized by dead angles where blood can stagnate and start to clot. This may cause progressive loss of gas exchange efficiency and, sometimes, force the perfusionist to change out the oxygenator during operation, which is, as already explained, a traumatic event as circulation needs to be momentarily interrupted. Moreover, polygonal fiber potting is often performed in more than two steps, which adds complexity and cost to manufacturing the oxygenator.

For the above reasons, manufacturers continue to improve the oxygenator devices.

Relevant prior art is for instance disclosed in documents <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

A device for conditioning blood according to the present invention comprises the technical features of independent claim <NUM>. Preferred embodiments thereof are as defined in dependent claims <NUM>-<NUM>. A method of manufacturing a device for conditioning blood according to the present invention comprises the technical features of independent claim <NUM>. Preferred embodiments thereof are as defined in dependent claims <NUM>-<NUM>.

While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure.

While the disclosure is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the disclosure to the embodiments described. On the contrary, the invention is defined by the appended claims.

<FIG> is a diagram illustrating a system <NUM> configured to condition blood during extracorporeal circulation, in accordance with embodiments of the subject matter of the disclosure. The system <NUM> includes a blood conditioning device <NUM>, also referred to as a modular blood conditioning device <NUM>. In embodiments illustrated in <FIG>, the device <NUM> includes a heat exchanger 22a configured to exchange heat with the blood, a gaseous micro-emboli (GME) removal module 22b configured to remove gaseous micro-emboli from the blood, and a gas exchanger 22c, also referred to as an oxygenator 22c, configured to exchange O2 and CO2 with the blood.

In other embodiments, the device <NUM> includes different functional components or modules. In some embodiments, the device <NUM> includes only an oxygenator 22c configured to exchange O2 and CO2 with the blood. In some embodiments, the device <NUM> includes only a heat exchanger 22a configured to exchange heat with the blood and an oxygenator 22c configured to exchange O2 and CO2 with the blood. In some embodiments, the device <NUM> includes only a GME removal module 22b configured to remove gaseous micro-emboli from the blood and an oxygenator 22c configured to exchange O2 and CO2 with the blood. In some embodiments, the system <NUM> includes other components, such as other heat exchangers, GME removers, and gas exchangers. In some embodiments, these components or modules are structurally integrated into the device <NUM>. In other embodiments, these components or modules are exchangeable, such that various modules may be easily added or removed from the device <NUM>.

The system <NUM> includes the device <NUM>, a processing unit <NUM>, and a blood reservoir <NUM>. In embodiments, the processing unit <NUM> may be a heart lung machine (HLM) or part of an HLM, as used in cardiopulmonary bypass surgery. Also, embodiments of the subject matter described herein may be implemented within the context of any number of different processing units, blood reservoirs, heat exchangers, GME removers, and oxygenators.

The processing unit <NUM> includes components, such as pumps, one or more controller assemblies including computing devices, one or more peripheral display devices, and one or more user interfaces, for providing the functions of the system <NUM>. The functions of the system <NUM> include receiving blood from a patient <NUM>, providing the blood to the blood reservoir <NUM>, and supplying the blood from the blood reservoir <NUM> to the blood conditioning device <NUM>. After being conditioned in the device <NUM>, the blood can be returned to the patient <NUM>.

The processing unit <NUM> is operatively coupled to the patient <NUM> and to the extracorporeal blood circulation system. Blood is taken from the patient <NUM> by means of a venous blood tubing line <NUM> and received by the blood reservoir <NUM>. Besides this, blood may be aspirated into the reservoir <NUM> by means of one or more suckers from the operating field and be otherwise received into the blood reservoir <NUM> from the patient <NUM>. In embodiments, the blood reservoir <NUM> includes a filter for filtering the blood received from the patient <NUM> and the operating field, prior to passing the blood to the device <NUM>.

The device <NUM> is fluidly coupled to the blood reservoir <NUM> to receive the blood from the blood reservoir <NUM>. A roller, or centrifugal blood pump <NUM> that is controlled by processing unit <NUM> may be interposed between the blood reservoir <NUM> and the blood conditioning device <NUM>. The pump <NUM> is fluidly coupled to the blood reservoir by blood tubing line <NUM> and fluidly coupled to the device <NUM> by blood tubing line <NUM>. The pump <NUM> is used for pumping blood from the outlet port of the blood reservoir <NUM> through the blood tubing line <NUM> and to the inlet port of the device <NUM> through the blood tubing line <NUM>.

The device <NUM> is coupled to a heater/cooler <NUM> that provides a fluid, such as water, at a controlled temperature to the heat exchanger 22a through inlet fluid tubing line <NUM> for heating/cooling the blood. The heater/cooler <NUM> receives returning fluid from the blood conditioning device <NUM> through the outlet fluid tubing line <NUM>. In embodiments, the heater/cooler <NUM> is controlled by the processing unit <NUM>.

The device <NUM> is further fluidly coupled to vacuum source <NUM> by fluid tubing line <NUM> for applying a vacuum through the fluid tubing line <NUM> to the GME removal module 22b. Alternatively, atmospheric pressure may be provided to the GME removal module 22b, such as by keeping the fluid tubing line <NUM> open to the atmosphere. In embodiments, the fluid tubing line <NUM> provides from atmospheric pressure to a vacuum of -400mmHG to the GME removal module 22b for removing GME from the blood. In embodiments, the vacuum source <NUM> is controlled by the processing unit <NUM>.

The device <NUM> is further fluidly coupled to a gas mixture module or gas blender <NUM> by inlet fluid tubing line <NUM>. The gas blender <NUM> provides oxygenation gases to the oxygenator 22c through inlet fluid tubing line <NUM> to oxygenate the processed blood. The gas outlet <NUM> of the device <NUM> is kept fully open to the atmosphere, such that given the pressure losses in the oxygenator gas, oxygenation takes place, as usually happens with all existing oxygenators, with the oxygenation gases at pressure values slightly over or close to atmospheric pressure values. In embodiments, the gas blender <NUM> is controlled by the processing unit <NUM>.

The device <NUM> receives the blood from the reservoir <NUM> through the blood tubing line <NUM> and processes the blood by exchanging heat with the blood in the heat exchanger 22a, removing GME from the blood in the GME removal module 22b, and oxygenating the blood in the oxygenator 22c. The device <NUM> returns the processed blood to the patient <NUM> through blood tubing line <NUM>. In embodiments, the device <NUM> is operatively coupled to the processing unit <NUM>, which controls the return of the temperature-controlled, degassed, and oxygenated blood to the patient <NUM> through the blood tubing line <NUM>, such as an arterial line.

<FIG> and <FIG> are diagrams illustrating a modular blood conditioning device <NUM>, in accordance with embodiments of the subject matter of the disclosure. <FIG> is a diagram illustrating a top view of the modular blood conditioning device <NUM>, in accordance with embodiments of the subject matter of the disclosure. <FIG> is a diagram illustrating a longitudinal section view of the modular blood conditioning device <NUM>, in accordance with embodiments of the subject matter of the disclosure. In embodiments, the blood conditioning device <NUM> is like the blood conditioning device <NUM> (shown in <FIG>). In embodiments, the device <NUM> can be used in place of device <NUM> in system <NUM>.

Generally, the device <NUM> includes a blood inlet cap <NUM>, a heat exchanger module <NUM>, a GME removal module <NUM>, a gas exchanger or oxygenator module <NUM>, and a blood outlet cap <NUM>. Each of the modules, including the heat exchanger module <NUM>, the GME removal module <NUM>, and the gas exchanger module <NUM>, includes a pile of stacked single hollow fiber mat layers that are alternatively stacked at <NUM>° angles. That is, each of the hollow fiber mat layers includes a layer of hollow fibers that are parallel to one another and define the hollow fiber direction for that layer. These layers are alternatively stacked with <NUM>° angle hollow fiber directions. Also, the characteristics of the hollow fiber mat layers in one module may be and often are different from the characteristics of the hollow fiber mat layers in the other modules.

The three modules are potted with a potting material (resin) in a single step to form a single potting material body <NUM> that defines a single, unified, cylindrical blood compartment <NUM> through the three modules. End portions of the hollow fibers of the hollow fiber mat layers are embedded in the potting material body <NUM> and the internal surface of the potting material body <NUM> circumscribes and defines the blood compartment <NUM>. The blood compartment <NUM> provides a blood flow path through the three modules, where the blood flows on the outside of the hollow fibers of the hollow fiber mat layers of the three modules. This results in the device <NUM> having a cylindrical internal shape for the blood to flow through from the blood inlet cap <NUM> to the blood outlet cap <NUM>.

Further, during manufacturing the ends of the hollow fibers of the hollow fiber mat layers of the three modules are embedded in the potting material that eventually becomes the potting material body <NUM>. This leads to the potting material having an outside squared cross-section that is cut away on the external surfaces to expose the inner lumens of the hollow fibers of the hollow fiber mat layers and provide access to the inner lumens of the hollow fibers from outside the potting material body <NUM>. Each of the three modules is further fitted with an external housing that includes one or more connectors to provide appropriate fluids/gases to the device.

Thus, device <NUM> includes stacked hollow fiber mat layers such that the blood flows outside the hollow fibers from the blood inlet cap <NUM> to the blood outlet cap <NUM> in a direction that is transverse to the stacked hollow fiber mat layers. This results in a shorter blood flow path than in a cylindrically wound blood conditioner and the resulting pressure gradient is lower, which reduces or prevents mechanical damage to blood cells. Also, the blood compartment <NUM> is cylindrical such that the blood flow path does not include dead angles where blood can stagnate and start to clot. In addition, the potting material (resin) is applied to all three modules in one step to provide a single, unified, blood compartment <NUM>, which reduces the complexity and cost of manufacturing the device <NUM>.

As illustrated in <FIG> and <FIG>, the blood inlet cap <NUM> includes a blood inlet port <NUM> through which blood enters the device <NUM> and a purging line port <NUM> through which air can be purged from the device <NUM>. In embodiments, as illustrated, the blood inlet port <NUM> is situated tangentially on the blood inlet cap <NUM> and the purging line port <NUM> is situated at the center of the blood inlet cap <NUM>. In other embodiments, the blood inlet port <NUM> can be situated at the center of the blood inlet cap <NUM>.

The blood enters the device <NUM> through the blood inlet port <NUM> as shown by arrow 170a and flows in a circular motion around the blood inlet cap <NUM> and into the cylindrical blood compartment <NUM>. In embodiments, as illustrated, the blood flows through the blood inlet port <NUM> of the blood inlet cap <NUM> and then through the heat exchanger module <NUM>, the GME removal module <NUM>, and the gas exchanger module <NUM> before exiting the device <NUM> through the blood outlet port <NUM> of the blood outlet cap <NUM> as shown by arrow 170b.

The first module in the cascade of three modules to be crossed by the blood is the heat exchanger module <NUM>. The heat exchanger module <NUM> includes heat exchanger hollow fibers in stacked heat exchanger hollow fiber mat layers <NUM>. The heat exchanger hollow fibers at <NUM> are configured to receive a heat exchanger fluid, such as water, for exchanging heat with the blood.

The heat exchanger module <NUM> includes a heat exchanger housing <NUM> that is external to the potting material body <NUM> and that includes a fluid inlet port <NUM> and a fluid outlet port <NUM>. The heat exchanger housing <NUM> is sealed to the potting material body <NUM> to prevent heat exchanger fluid from leaking out and divided into two inner chambers, an inlet fluid chamber <NUM> and an outlet fluid chamber <NUM>. The heat exchanger housing <NUM> is divided into the two inner chambers, by two diametrically opposed longitudinal spacers <NUM> and <NUM> (shown in <FIG>). The inlet fluid chamber <NUM> puts the fluid inlet port <NUM> in fluid communication with one side or end of the heat exchanger hollow fibers at <NUM>. The outlet fluid chamber <NUM> puts the fluid outlet port <NUM> in fluid communication with the opposite side or end of the heat exchanger fibers at <NUM>. The heat exchanger fluid (e.g., water) flows from the inlet fluid port <NUM> and the inlet fluid chamber <NUM> into the inner lumens of the heat exchanger hollow fibers at <NUM> and is collected at the outlet fluid chamber <NUM> to exit the device <NUM> through the fluid outlet port <NUM>, before being circulated back to the heater/cooler equipment, such as heater/cooler <NUM> (shown in <FIG>). The heat exchanger housing <NUM> is the first of three module housings, where each of them is sealed to the external surface of the potting material body <NUM> and encloses one of the three modules.

Also, in embodiments, the device <NUM> includes blood inlet cap supports <NUM> embedded in the potting material body <NUM> and extending above the heat exchanger hollow fiber mat layers <NUM>. The blood inlet cap <NUM> is attached to and supported by the blood inlet cap supports <NUM>. In embodiments, the device <NUM> includes an inlet cap spacer <NUM> situated on the heat exchanger hollow fiber mat layers <NUM> and embedded in the potting material body <NUM>. In embodiments, the device <NUM> includes the blood inlet cap supports <NUM> attached to or on the inlet cap spacer <NUM>.

In addition, in embodiments, the device <NUM> includes a module spacer <NUM> between the heat exchanger module <NUM> and the GME removal module <NUM>. The module spacer <NUM> is embedded into the potting material body <NUM>. In embodiments, the module spacer <NUM> is made of plastic.

The second module in the cascade of three modules to be crossed by the blood is the GME removal module <NUM>. The GME removal module <NUM> includes micro-porous hollow fibers in stacked micro-porous hollow fiber mat layers <NUM>. The GME micro-porous hollow fibers at <NUM> are different from the heat exchanger hollow fibers at <NUM>, in that the micro-porous hollow fibers at <NUM> are permeable to gas and impermeable to liquids, while the heat exchanger hollow fibers at <NUM> are permeable only to energy or heat. Also, the heat exchanger hollow fiber mats <NUM> and the micro-porous hollow fiber mats <NUM> may differ in fiber linear density, dimensions, and number of warp yarns.

In the GME removal module <NUM>, atmospheric pressure or sub-atmospheric pressure (a vacuum) is applied to the inner lumens of the micro-porous hollow fibers at <NUM> to pull GME from the blood through the walls of the micro-porous hollow fibers at <NUM>. This removes the GME form the blood, where the GME needs to be removed from the blood before returning the blood to the patient in order to avoid embolization.

The GME removal module <NUM> includes a GME removal module housing <NUM> that includes a fluid outlet <NUM> in fluid communication with at least one side of the micro-porous hollow fibers at <NUM>. The GME removal module housing <NUM> is sealed to the potting material body <NUM> and provides atmospheric or sub-atmospheric pressures received at the fluid outlet <NUM> to the micro-porous hollow fibers at <NUM>. In embodiments, the fluid outlet <NUM> is in fluid communication with an inner chamber <NUM> that is in fluid communication with all sides of the micro-porous hollow fibers at <NUM>.

The third module in the cascade of three modules to be crossed by the blood is the gas exchanger or oxygenator module <NUM>. In embodiments, the device <NUM> includes a module spacer <NUM> situated between the GME removal module <NUM> and the gas exchanger module <NUM>. The module spacer <NUM> includes, on the GME removal module <NUM> side, a filter screen <NUM> whose function is to retain gaseous micro-emboli in the GME removal module <NUM> to facilitate their removal. The module spacer <NUM> and the filter screen <NUM> are embedded into the potting material body <NUM>. In embodiments, the module spacer <NUM> and/or the filter screen <NUM> are made of plastic.

The gas exchanger module <NUM> includes gas exchanger hollow fibers in stacked gas exchanger hollow fiber mat layers <NUM>. The gas exchanger hollow fibers at <NUM> are configured to receive a gas mixture and exchange gas with the blood. The gas exchanger hollow fibers at <NUM> are different from the heat exchanger hollow fibers at <NUM>, in that the gas exchanger hollow fibers at <NUM> are permeable to gas and impermeable to liquids, while the heat exchanger hollow fibers at <NUM> are permeable only to energy or heat. Also, the heat exchanger hollow fiber mat layers <NUM>, the micro-porous hollow fiber mat layers <NUM>, and the gas exchanger hollow fiber mat layers <NUM> may each differ in fiber linear density, dimensions, and number of warp yarns.

The gas exchanger module <NUM> includes a gas exchanger housing <NUM> that includes opposed gas exchanger fluid connectors, a gas inlet port <NUM> and a gas outlet port <NUM>. The gas exchanger housing <NUM> is sealed to the potting material body <NUM> to prevent the gas mixture from leaking out. The gas exchanger housing <NUM> is divided into two inner chambers, an inlet gas chamber <NUM> and an outlet gas chamber <NUM>, by the two diametrically opposed longitudinal spacers 136A and 138A (shown in <FIG>). The inlet gas chamber <NUM> puts the gas inlet port <NUM> in fluid communication with one side or end of the gas exchanger hollow fibers at <NUM>. The outlet gas chamber <NUM> puts the gas outlet port <NUM> in fluid communication with the opposite side or end of the gas exchanger fibers at <NUM>. In this way, the gas mixture flows from the gas inlet port <NUM> and the gas inlet chamber <NUM> into the inner lumens of the gas exchanger hollow fibers at <NUM> and is collected at the gas outlet chamber <NUM> to exit the device <NUM> through the gas outlet port <NUM>.

In embodiments, the device <NUM> includes one or more blood outlet cap supports <NUM> embedded in the potting material body <NUM>. Also, in embodiments, the device <NUM> includes an arterial blood filter <NUM> situated under the gas exchanger module <NUM> and between the gas exchanger module <NUM> and the blood outlet cap <NUM>. The arterial blood filter <NUM> is obtained with one or more screen layers of suitable size, such as <NUM> to <NUM> microns, and embedded in the potting material body <NUM>. In operation, the blood flows through the gas exchanger module <NUM> and the arterial blood filter <NUM> into the blood outlet cap <NUM> and out of the device <NUM> through the blood outlet port <NUM>.

In other embodiments, the device <NUM> may include only one or two of: the heat exchanger module <NUM>; the GME removal module <NUM>; and the gas exchanger module <NUM>. These different embodiments may be used in different applications. In some embodiments, such as extracorporeal membrane oxygenation (ECMO) or extracorporeal life support (ECLS), the heat exchanger module <NUM> may not be needed. In some embodiments, such as for cardiac surgery, the device <NUM> can include at least the heat exchanger module <NUM> and the oxygenator module <NUM>. In some embodiments, the GME removal module <NUM> is included for extra safety by eliminating or reducing the GME in the blood.

The flow of heat exchanger fluid, such as water, and gas exchanger fluid, such as oxygen, through the hollow fiber mat layers is shown by arrows in <FIG>. As shown by arrows 172a - 172c, the heat exchanger fluid flows through the heat exchanger module <NUM> from the fluid inlet port <NUM> at arrow 172a, through the heat exchanger hollow fibers at <NUM> at arrow 172b, and through the fluid outlet port <NUM> at arrow 172c. As shown by arrows 174a - 174c, the gas exchanger fluid flows through the gas exchanger module <NUM> from the gas inlet port <NUM> at arrow 174a, through the gas exchanger hollow fibers at <NUM> at arrow 174b, and through the gas outlet port <NUM> at arrow 174c. As shown by arrow <NUM>, the GME are removed from the GME removal module <NUM> at arrow <NUM>. In various alternative embodiments, the device <NUM> can be configured such that the heat exchanger fluid and the gas exchanger fluid flow through the device <NUM> in opposing directions.

<FIG> are diagrams illustrating the construction of the device <NUM>, in accordance with embodiments of the subject matter of the disclosure. Each of the modules, including the heat exchanger module <NUM>, the GME removal module <NUM>, and the gas exchanger module <NUM>, includes a pile of stacked single hollow fiber mat layers that are alternatively stacked at <NUM>° angles. That is, each of the hollow fiber mat layers includes a layer of hollow fibers that are parallel to one another and define the hollow fiber direction for that layer. These layers are alternatively stacked with <NUM>° angle hollow fiber directions. Also, the characteristics of the hollow fibers in one module may be different from the characteristics of the hollow fibers in the other modules. Construction of one hollow fiber mat layer is described below, where the same construction technique can be used for each of the hollow fiber mat layers in the heat exchanger module <NUM>, the GME removal module <NUM>, and the gas exchanger module <NUM>.

<FIG> is a diagram illustrating the construction of a hollow fiber mat layer <NUM> used in the device <NUM>, in accordance with embodiments of the subject matter of the disclosure. The hollow fiber mat layer <NUM> is to be stacked in one of the modules and has a rectangular shape, where H corresponds to the height and W to the width, with the height H greater than the width W. In embodiments, each of the hollow fiber mat layers has the same height H and width W dimensions for all three of the modules.

The hollow fiber mat layer <NUM> is obtained by knitting a mat or weave that has a discontinued weft and cutting the weave into pieces at spaces <NUM> where the weft is missing. The hollow fiber mat layer <NUM> includes hollow fibers <NUM> as the weft and yarn <NUM> as the warp. A single layer of hollow fibers <NUM> is knitted into a rectangle having the height H of the hollow fibers <NUM> and the width W. The weft is discontinued, such that the spaces <NUM> having width <NUM> are left between the hollow fiber mat layer <NUM> and other mat layers that may be knit on each side of the hollow fiber mat layer <NUM>. The yarn <NUM> is cut at <NUM> in the middle of the spaces <NUM> (<NUM> from the hollow fiber mat layer <NUM>) on each side of the hollow fiber mat layer <NUM> to remove the hollow fiber mat layer <NUM>. In embodiments, an adhesive layer <NUM> having a width WA is attached to the top and to the bottom of the hollow fibers <NUM>. In embodiments, hollow fiber mat layers may be knit with different materials, have different fiber dimensions, have different linear density, and have a different number of warp yarns for each of the modules.

<FIG> is a top view diagram illustrating the components of the device <NUM>, including the modules <NUM>, <NUM>, and <NUM>, piled into a potting mold <NUM> and ready for potting, in accordance with embodiments of the subject matter of the disclosure. For each of the modules <NUM>, <NUM>, and <NUM>, hollow fiber mat layers, such as hollow fiber mat layer <NUM>, are stacked by alternatively crossing them at <NUM>°, one on top of the other, according to the number of hollow fiber mat layers prescribed for the module. Each of the hollow fiber mat layers has a height H and a width W. The modules are situated in the potting mold <NUM>, which keeps them aligned. In embodiments, different modules can have a different number of hollow fiber mat layers.

In embodiments, the components of the device <NUM> are piled into the potting mold <NUM> in the following order. First, the blood outlet cap supports <NUM> (shown in <FIG>) are situated or inserted into the potting mold <NUM> followed by the arterial blood filter <NUM>. Next, the gas exchanger module <NUM> is piled in the potting mold <NUM> followed by the module spacer <NUM> and the GME removal module <NUM>. Next, the module spacer <NUM> is piled into the potting mold <NUM> followed by the heat exchanger module <NUM>, the inlet cap spacer <NUM>, and the blood inlet cap supports <NUM>.

With all of these components loaded into the potting mold <NUM>, potting is done in one step by spinning the potting mold <NUM> around the vertical axis Z at a certain speed and introducing the liquid potting material (resin) into the potting mold <NUM>. The liquid potting material spreads to the outside of the potting mold <NUM> due to centrifugal forces and embeds the components of the device <NUM> in the potting material. At the end of the potting phase, the central portion of the potting material pack, which is the cylindrical blood compartment <NUM>, is an open space occupied by the stacked horizontal hollow fiber mat layers of the modules and circumscribed by the inner surface <NUM> of the potting material body <NUM>. The outer surface of the potting material has the same shape of the potting mold <NUM>, that can be removed after resin curing, resulting in a potted body of the device <NUM>. In embodiments, the potting mold <NUM> includes silicon rubber.

The diameter D (shown in <FIG>) of the inner surface of the potting material body <NUM> can be calculated to be equal to the width W of the hollow fiber mat layers. If it is, the open space in the blood compartment <NUM> is evenly occupied by <NUM>° crossed hollow fibers, such that no preferential channels are created in the blood flow path and no hollow fibers are completely embedded in the potting material and cut off from contact with the blood. If it is not, the exchange efficiencies of the device <NUM> may be less than optimal.

<FIG> is a diagram illustrating a cross sectional view of the potted body <NUM> of the device <NUM>, in accordance with embodiments of the subject matter of the disclosure. The potted body <NUM> has the shape of the potting mold <NUM>.

After removing the potting mold <NUM>, the potted body <NUM> is ready for being cut to form the outside of the potting material body <NUM>. In this phase of the construction, access to the inner lumens of the hollow fibers is obtained by removing the potting material (resin) that covers the ends of the hollow fibers. As illustrated, a thin slice E of the potting material is removed from each outer side of the potted body <NUM>, where E must be large enough for exposing the ends of the hollow fibers on all sides of the potted body <NUM>. This results in the cross-section of the cut potted body <NUM> being inscribed in a square having a side C=W+2T=H-2E, where T is the potting material minimum thickness.

<FIG> is a cross-section of the device <NUM> along the line A-A in <FIG>, corresponding to a middle height line of the gas exchanger module <NUM>, in accordance with embodiments of the subject matter of the disclosure. The gas exchanger housing <NUM>, including the gas inlet port <NUM> and the gas outlet port <NUM>, is situated around the cut potted body <NUM>, which is now the potting material body <NUM>, and sealed to the potting material body <NUM>. The diametrically opposed longitudinal spacers 136A and 138A are introduced with radial interference at two diametrically opposed corners to create the inlet gas chamber <NUM> and the outlet gas chamber <NUM>. The same or a similar construction is repeated for the heat exchanger module <NUM> and the GME removal module <NUM>, where the GME removal module housing <NUM> has only one fluid outlet <NUM> and one corresponding inner chamber <NUM>. In embodiments, the opposed longitudinal spacers 136A and 138A are made of rubber.

In assembly of the device <NUM>, the heat exchanger housing <NUM>, GME removal module housing <NUM>, and gas exchanger housing <NUM> are attached to the cut potted body <NUM>, which is now the potting material body <NUM>. The blood inlet cap <NUM> is attached to the blood inlet cap supports <NUM> and sealed adjacent the inlet cap spacer <NUM>, which is situated on the heat exchanger hollow fiber mat layers <NUM> and embedded in the potting material body <NUM>. The blood inlet cap <NUM> is shaped to impart a spiral flow direction to the entering blood, see <FIG>, such that if air bubbles are present, the induced centrifugal force moves them towards the central purging port <NUM> where they are easily removed by the purging line. In embodiments, this is useful during the device <NUM> initial priming with liquid.

The blood outlet cap <NUM> is attached to the blood outlet cap supports <NUM> that are embedded in the potting material body <NUM>. The blood outlet cap <NUM> is sealed adjacent the arterial blood filter <NUM> situated under the gas exchanger module <NUM> and between the gas exchanger module <NUM> and the blood outlet cap <NUM>.

In embodiments, laser welding can be used to seal one or more of the blood inlet cap <NUM>, the blood outlet cap <NUM>, the heat exchanger housing <NUM>, the GME removal module housing <NUM>, and the gas exchanger housing <NUM> to the underlying potting material body <NUM> to form the device <NUM>.

<FIG> and <FIG> are diagrams illustrating a blood conditioning device <NUM> including only a gas exchanger module, such as gas exchanger module <NUM>, in accordance with embodiments of the subject matter of the disclosure. <FIG> is a diagram illustrating an exploded view of the device <NUM>, in accordance with embodiments of the subject matter of the disclosure.

The device <NUM> includes a blood inlet cap <NUM>, a blood inlet cap spacer <NUM>, a cut potted body <NUM>, an arterial blood filter <NUM>, a gas exchanger housing <NUM>, and a blood outlet cap <NUM>. The blood enters the blood inlet cap <NUM> and flows through the blood inlet cap spacer <NUM>, the cut potted body <NUM>, and the arterial blood filter <NUM>, before exiting through the blood outlet cap <NUM>.

The blood inlet cap <NUM> includes a blood inlet port <NUM> through which blood enters the device <NUM> and a purging line port <NUM> through which air can be purged from the device <NUM>. In embodiments, as illustrated in <FIG> and <FIG>, the blood inlet port <NUM> is situated tangentially on the blood inlet cap <NUM> and the purging line port <NUM> is situated at the center of the blood inlet cap <NUM>. In other embodiments, the blood inlet port <NUM> can be situated at the center of the blood inlet cap <NUM>.

In embodiments as illustrated in <FIG>, the blood inlet cap spacer <NUM> may be embedded in the potting material of the cut potted body <NUM>, or the blood inlet cap spacer <NUM> may be a separate unit that is sealed, such as by adhesives or laser welding, onto the potted body <NUM> to prevent leakage of the blood. Also, the blood inlet cap <NUM> is sealed to and supported by blood inlet cap supports <NUM> that are part of the blood inlet cap spacer <NUM>. In embodiments, the blood inlet cap <NUM> is sealed, such as by adhesives or laser welding, to the blood inlet cap supports <NUM> to prevent leakage of the blood.

The cut potted body <NUM> includes gas exchanger hollow fiber mat layers <NUM> situated in a cylindrical blood compartment <NUM>. The cut potted body <NUM> is like the cut potted body <NUM> in that it has been constructed using the construction techniques used to construct the cut potted body <NUM>. The sides of the cut potted body <NUM> include exposed inner lumens of the gas exchanger hollow fibers at <NUM> in the gas exchanger hollow fiber mat layers <NUM>.

The gas exchanger housing <NUM> includes opposed gas exchanger fluid connectors, a gas inlet port <NUM> and a gas outlet port <NUM>. The gas exchanger housing <NUM> is sealed to the cut potted body <NUM> to prevent gas from leaking out. The gas exchanger housing <NUM> is divided into an inlet gas chamber and an outlet gas chamber by diametrically opposed longitudinal spacers <NUM> and <NUM> that are inserted in diametrically opposed corners of the gas exchanger housing <NUM>. These longitudinal spacers <NUM> and <NUM> are like the longitudinal spacers 136A and 138A (shown in <FIG>). In embodiments, the longitudinal spacers are made from or at least include rubber.

The inlet gas chamber puts the gas inlet port <NUM> in fluid communication with one side of the inner lumens of the gas exchanger hollow fibers at <NUM>. The outlet gas chamber puts the gas outlet port <NUM> in fluid communication with the opposite side of the inner lumens of the gas exchanger hollow fibers. In this way, gas flows from the gas inlet port <NUM> through the inner lumens of the gas exchanger hollow fibers and exits the device <NUM> through the gas outlet port <NUM>.

In embodiments as illustrated in <FIG>, the arterial blood filter <NUM> may be embedded in the potting material of the potted body <NUM>, or the arterial blood filter <NUM> may be a separate unit that is sealed, such as by adhesives or laser welding, onto the potted body <NUM> to prevent leakage of the blood.

The arterial blood filter <NUM> includes blood outlet cap supports <NUM> that are attached to a corresponding ring <NUM> on the blood outlet cap <NUM>. The ring <NUM> on the blood outlet cap <NUM> is sealed, such as by adhesives or laser welding, to the blood outlet cap supports <NUM> to prevent leakage of the blood. The gas exchanger housing <NUM> is further attached and sealed to the blood inlet cap <NUM> and to the blood outlet cap <NUM>.

In operation, a gas mixture is provided to the gas inlet port <NUM> to flow through the inner lumens of the gas exchanger hollow fiber mat layers <NUM> and out the gas outlet port <NUM>. The blood enters the device <NUM> through the blood inlet port <NUM> and flows in a circular motion around the blood inlet cap <NUM> and through the blood inlet cap spacer <NUM> and into the cylindrical blood compartment <NUM> of the potted body <NUM>. Next, the blood flows through the hollow fiber mat layers <NUM> and then through the arterial blood filter <NUM> and into the blood outlet cap <NUM>. The blood exits the device <NUM> through the blood outlet port <NUM> of the blood outlet cap <NUM>.

<FIG> is a diagram illustrating an assembled view of the device <NUM>, in accordance with embodiments of the subject matter of the disclosure. The device <NUM> includes the blood inlet cap <NUM> with the blood inlet port <NUM> and the blood outlet cap <NUM> with the blood outlet port <NUM>. The gas exchanger housing <NUM> includes the gas inlet port <NUM> and the gas outlet port <NUM> (not shown in <FIG>).

In operation, a gas mixture is provided to the gas inlet port <NUM> for flowing though the gas exchanger hollow fiber mats <NUM> and the blood is provided at the blood inlet port <NUM> to flow through the device <NUM> before exiting through the blood outlet port <NUM> of the blood outlet cap <NUM>.

<FIG> is a diagram illustrating an assembled view of another device <NUM>, in accordance with embodiments of the subject matter of the disclosure. The device <NUM> is like the device <NUM> except the blood inlet cap <NUM> has a centrally located blood inlet port <NUM> instead of a tangentially located blood inlet port. The device further includes a centrally located purging line port <NUM>, a blood outlet cap <NUM> with a blood outlet port <NUM>, and a gas exchanger housing <NUM> with a gas inlet port <NUM> and a gas outlet port (not shown).

In operation, a gas mixture is provided to the gas inlet port <NUM> for flowing though the gas exchanger hollow fiber mats and the blood is provided at the blood inlet port <NUM> to flow through the device <NUM> before exiting through the blood outlet port <NUM> of the blood outlet cap <NUM>.

<FIG> is a flow chart diagram illustrating a method of manufacturing a device for conditioning blood, in accordance with embodiments of the subject matter of the disclosure.

At <NUM>, the method includes stacking gas exchanger hollow fiber mat layers into a potting mold. In embodiments, the method further includes one or more of placing a blood outlet cap support in the potting mold and placing an arterial blood filter in the potting mold and then stacking the gas exchanger hollow fiber mat layers into the potting mold.

At <NUM>, the method includes stacking micro-porous hollow fiber mat layers over the gas exchanger hollow fiber mat layers in the potting mold. In embodiments, the method includes situating a first spacer between the gas exchanger hollow fiber mat layers and the micro-porous hollow fiber mat layers.

At <NUM> the method includes stacking heat exchanger hollow fiber mat layers over the micro-porous hollow fiber mat layers in the potting mold. In embodiments, the method includes situating a second spacer between the micro-porous hollow fiber mat layers and the heat exchanger hollow fiber mat layers and/or a blood inlet cap support on the heat exchanger hollow fiber mat layers, prior to spinning the potting mold around the longitudinal axis of the potting mold and introducing liquid potting material into the potting mold.

At <NUM>, the method includes spinning the potting mold around a longitudinal axis of the potting mold, and at <NUM>, the method includes introducing liquid potting material into the potting mold as the potting mold spins to embed the gas exchanger hollow fiber mat layers and the micro-porous hollow fiber mat layers and the heat exchanger hollow fiber mat layers in the potting material and create a blood compartment that extends through the gas exchanger hollow fiber mat layers and the micro-porous hollow fiber mat layers and the heat exchanger hollow fiber mat layers. Where, in embodiments, introducing the liquid potting material into the potting mold as the potting mold spins creates a cylindrical blood compartment defined by an inner diameter of the potting material.

At <NUM>, after potting material curing, the method includes removing the potting mold and cutting the potting material away to expose inner lumen ends of heat exchanger hollow fibers in the heat exchanger hollow fiber mat layers and inner lumen ends of micro-porous hollow fibers in the micro-porous hollow fiber mat layers and inner lumen ends of gas exchanger hollow fibers in the gas exchanger hollow fiber mat layer.

At <NUM>, the method includes sealing one or more of a heat exchanger housing to the potting material, a gaseous micro-emboli module housing to the potting material, and a gas exchanger housing to the potting material. Also, in embodiments, the method further includes attaching a blood inlet cap and attaching a blood outlet cap.

Claim 1:
A device (<NUM>) for conditioning blood comprising:
a heat exchanger module (<NUM>) including a heat exchanger fiber layer (<NUM>) including heat exchanger fibers configured to receive a heat exchanger fluid and exchange heat with the blood;
a gaseous micro-emboli removal module (<NUM>) including a micro-porous fiber layer (<NUM>) including micro-porous fibers configured to receive atmospheric or sub- atmospheric pressures such that at least some gaseous micro-emboli are drawn from the blood through the micro-porous fibers;
a gas exchanger module (<NUM>) including a gas exchanger fiber layer (<NUM>) including gas exchanger fibers configured to receive a gas mixture and exchange gas with the blood; and
a potting material body (<NUM>) that embeds the heat exchanger fibers, the micro-porous fibers and the gas exchanger fibers and defines a blood compartment (<NUM>) that extends through the heat exchanger module (<NUM>), the gaseous micro-emboli removal module (<NUM>), and the gas exchanger module (<NUM>);
characterized by at least one of:
the heat exchanger module (<NUM>) including stacked heat exchanger hollow fiber mat layers (<NUM>), wherein the heat exchanger hollow fiber mat layers (<NUM>) are alternatively orthogonally angled from one another;
the gaseous micro-emboli removal module (<NUM>) including stacked micro-porous hollow fiber mat layers (<NUM>), wherein the micro-porous hollow fiber mat layers (<NUM>) are alternatively orthogonally angled from one another; and
the gas exchanger module (<NUM>) including stacked gas exchanger hollow fiber mat layers (<NUM>), wherein the gas exchanger hollow fiber mat layers (<NUM>) are alternatively orthogonally angled from one another.