Blood pump assembly, system and methods

Abstract

Title: Blood pump assembly, system and methods Abstract Blood pump assembly (1) for blood circulation in a mammal, comprising: a flexible wall structure (2) bounding a first pump chamber (3); a first blood inlet (4) for blood to flow into the first pump chamber (3); and a first blood outlet (5) for blood to flow out of the first pump chamber (3). A series of pouches (6) distributed along a circumferential direction (CD) of the first pump chamber (3) is arranged to cause contraction of the wall structure (2) upon filling of the pouches (6). The assembly (1) is configured to be fluidically connected to a drive unit (7) for driving a driving fluid into the pouches (6) for filling the pouches (6). [Fig. 3A]

Description

P 137745NL00 Title: Bloodpump assembly, system and methods FIELD The invention relates to a bloodpump assembly for blood circulation in a mammal, as well as to a bloodpumping system comprising the bloodpump assembly, a method ofmanufacturing the bloodpump assembly, a method ofoperating the bloodpumping system, and a method of providing a bloodpumping function in the circulatory system ofa mammal. BACKGROUND Artificial bloodpumping systems for blood circulation in a mammal, in some cases called artificial hearts, are known as such. In recent years, researchers have been exploring the use ofexible structures for pump chambers and actuation mechanisms in such systems, see for example WO 2024 / 023749 A1 andWO 2021 / 260614 A1. It is considered that, compared to more traditional rigid structures, such exible structures can potentially provide a higher degree ofsimilarity to a natural heart, e.g. regarding size, weight and mechanical behavior. There is nevertheless a desire for further improvements in this field, in particular regarding durability, efcacy, efficiency, implantability, hemocompatibility, adaptability to physiological variations and / or customizability. SUMMARY An aim is to provide improvements with respect to articial blood pumping systems for blood circulation in a mammal, in particular regarding durability, efcacy, efciency, implantability, hemocompatibility, adaptability to physiological variations and / or customizability. An aim is to provide an alternative design for a bloodpump assembly for such a system. An aim is to facilitate partial or total replacement ofa mammals natural heart. An aspect ofthe invention provides a bloodpump assembly for blood circulation in amammal, comprising: a exible wall structure bounding a firstpump chamber; a rst blood inlet for blood to ow into the firstpump chamber; and a rst blood outlet for blood toow out ofthe first pump chamber.A series ofpouches distributed along a circumferential direction ofthe firstpump chamber is arranged to cause contraction ofthe wall structure upon filling ofthe pouches. The assembly is congured to be uidically connected to a drive unit for driving a driving uid into the pouches for lling the pouches. By providing the series ofllable pouches along the exible wall structure, a particularly efficient and durable contraction mechanism can be provided for the firstpump chamber, whichmay be regarded as an artificial cardiac ventricle. Advantageously, it has been found that the bloodpump assembly can be relatively compact and light-weight while providing a relatively high bloodpumping capacity, and that the bloodpump assembly can mimic compliant mechanical behavior of a natural heart to a relatively high degree. Notably, using the series ofpouches, such compliance can be provided without requiring the wall structure material to be extensible, in particular using mobility and / or compressibility ofthe driving uid and exibility ofthe wall structure. Also, it has been found that using lling ofthe pouches, the wall structure can deform relatively smoothly, which can promote hemocompatibility and prevent clotting. Meanwhile, such a design ofthe bloodpump assembly facilitates customization, for example in terms of size ofthe firstpump chamber, and allows to avoid the use ofmachined parts and electronics such as sensor electronics in the bloodpump assembly. Thanks to the pouches being distributed along the wall structure, the contraction ofthe wall structure can be relatively efcient and well controlled, in particular so as to mimic contraction of a natural heart to a relatively high degree. Upon lling, the pouches will transition from a relatively at shape to a more swollen, e.g. substantially cylindrical, shape. This then reduces the widths ofthe pouches along the circumferential direction ofthe firstpump chamber . The combined width reductions ofthe pouches translate into a reduced overall circumferential size ofthe wall structure when the pouches are filled, thereby causing a contraction that reduces an inner volume ofthe firstpump chamber. Additional reduction of this inner volume is provided by an inward bulging ofthe filled pouches. Thanks to the pouches being distributed along the circumferential direction, the contraction ofthe wall structure can facilitate a relatively effective and efficient pumping function. The uidic nature ofthe driving mechanism enables the drive unit to be arranged at a relatively convenient location at a distance from the bloodpump assembly, for example using a uidic drive line therebetween, without requiring a complex or bulky or sensitive mechanical transmission. Advantageously, the bloodpump assemblymay be configured to reduce a totalpump chamber volume ofthe firstpump chamber during the contraction by an amount, i.e. a blood stroke volume, that is larger than a total volume increase ofthe pouches during the contraction, i.e. a pouch filling volume. It has been found that such a performance can be achieved using congurations ofthe bloodpump assembly as described herein. In particular, without wishing to be boundby theory, it is considered that such a performance can be achievedwhen selecting the number ofpouches to be relatively high, e.g. at least ten. More generally, the present invention advantageously provides a relatively high level ofdesign freedom with respect to the number ofpouches, which in turn can provide a desired ratio ofblood stroke volume to pouch filling volume, in particular in combination with a pressure ofthe driving uid. By way of analogy, such a ratio may at least to some extent be compared to a gear ratio in a gear transmission, in the sense that relative gear sizes can determine ratios of distance and force. A further aspect provides a bloodpumping system for blood circulation in a mammal, comprising the bloodpump assembly as described herein and the drive unit. A further aspect provides a method ofoperating a bloodpumping system as described herein, comprising, using the drive unit uidically connected to the bloodpump assembly, driving the driving uid in a periodic manner to periodically contract the wall structure. A further aspect provides a method ofproviding a bloodpumping function in the circulatory system ofa mammal, comprising: providing a bloodpumping system as described herein; uidically connecting the rst blood inlet to a vein ofthe mammal; and uidically connecting the rst blood outlet to an artery ofthe mammal. Advantages ofthe bloodpumping system, the method ofoperating and the method ofproviding a bloodpumping function correspond to advantages ofthe bloodpump assembly as described herein. Using the blood pumping system, part or all ofa mammals natural heartmay be replaced, for example in case the natural heart is diseased or damaged and a suitable donor heart is not available. The mammalmay be ahuman or a non-human mammal. A further aspect provides a method ofmanufacturing a bloodpump assembly as described herein, comprising: providing two mutually overlapping exible sheet parts; locally mutually attaching the two sheet parts along predened paths comprising path sections corresponding to boundaries between adjacent ones ofthe pouches; and forming at least part ofthe wall structure from the locally mutually attached exible sheet parts. Such a method allows the bloodpump assembly to be manufactured in a relatively effective and efcient manner, in particular while facilitating customization. Optional advantageous elaborations ofthe above aspects are indicated in the dependent claims and the below detailed description. DETAILED DESCRIPTION In the following, the invention will be explained further using examples ofembodiments and drawings. The drawings are schematic and merely show examples. In the drawings, corresponding elements are provided with corresponding reference signs. For clarity ofthe drawings, some reference signs may be omitted, in particular where the meaning of shown elements is apparent from similar elements being provided with reference signs. Descriptions ofembodiments herein can also be understood without reference to the drawings, and are thus not inextricably linked to examples shown in the drawings. In the drawings: Fig. 1A shows a cross sectional top view ofa wall structure, with pouches in a substantially empty state; Fig. 1B shows a cross sectional top view ofthe wall structure of Fig. 1A, with the pouches in a substantially full state so that the wall structure is more contracted compared to Fig. 1A; Figs. 2A and 2B show paths for local attachments ofsheet parts and a folding line in subsequent steps ofmanufacturing a bloodpump assembly; Fig. 3A shows a side view of a bloodpump assembly in a partly contracted state; Figs. 3B and 3C show cross sectional top views ofthe bloodpump assembly ofFig. 3A along the lines B-B and C-C in Fig. 3A, respectively; Fig. 4 shows a diagram ofa bloodpumping system; Figs. 5A and 5B show cross sectional top views substantially corresponding to the views of Figs. 3B and 3C, respectively, of a variation of the bloodpump assembly ofFigs. 3A-C; Fig. 6 shows an experimental measurement result; Fig. 7 shows variations ofthe paths of Fig. 2A resulting in different numbers ofpouches; Fig. 8A shows a side view and a simplied cross-sectional side view of a wall structure with pouches similar to those of Figs. 3A-C, wherein in the simplied cross-sectional side view the wall structure is shown in both a less or not contracted state and a more contracted state; and Fig. 8B shows a side view and simplified cross-sectional side view corresponding to the views of Fig. 8A of a variation ofthe wall structure wherein pouches are distributed not only along the circumferential direction but also along a length direction. Figs. 2B, 3A-C, 4, and 5A-B show examples of a bloodpump assembly 1 for blood circulation in ahuman or other mammal, comprising: a exible wall structure 2 bounding a firstpump chamber 3; a rst blood inlet 4 for blood to ow into the firstpump chamber 3; and a rst blood outlet 5 for blood to ow out ofthe rst pump chamber 3. The exibility ofthe wall structure 2 is preferably provided using one or more thin sheets ofbendable material, optionally comprising woven or non-woven fibers to promote durability and / or to limit extensibility. A series ofpouches 6 is distributed along a circumferential direction CD ofthe firstpump chamber 3is arranged to cause contraction of the wall structure 2 upon filling ofthe pouches 6. Upon subsequent emptying ofthe pouches 6, the wall structure 2 may expand again, in particular under pressure from blood in the rst pump chamber 3. To facilitate the contraction ofthe wall structure 2, the pouches 6 are preferably formed from a substantially inextensible material. In particular, under expected operating loads, the material ofthe pouches may be congured to exhibit strain ofless than 5%, preferably less than 2%, more preferably less than 1%, even more preferably less than 0.5%. In this respect, it shall be appreciated that the expected operating loads mainly depend on the uid pressure in the pouches, whichmay be at a similar level as themaximum blood pressure in thepump chamber, or somewhat higher. In possible examples, the above-mentioned strain levelmay be measured at a uid pressure in the pouches of 0.2 bar, 0.3 bar, 0.4 bar or 0.5 bar. It shall be appreciated that any strain in the material ofthe pouches 6 is preferably elastic. Such elasticity not only prevents gradual widening ofthe pouches butmay also contribute to an advantageous compliance in the mechanical behavior ofthe bloodpump assembly. In some variants, the elasticity or stiffness ofthe materialmay be non-uniform across different regions ofthe pouches 6 and / or the wall structure 2, e.g. with higher elasticity in regions that are subjected to higher localized loads due to geometrical constraints. The assembly 1 is congured to be uidically connected to a drive unit 7 for driving a drivinguid into the pouches 6 for lling the pouches 6. Fig. 4 shows a bloodpumping system 17 for blood circulation in a mammal, comprising the bloodpump assembly 1 as described herein and the drive unit 7. Here, a uidic drive line 10 operatively interconnects the drive unit 7 and the bloodpump assembly 1, for example using a dedicated connector 18 ofthe bloodpump assembly 1. The drive unit 7 preferably comprises apump for pumping the driving uid to the bloodpump assembly 1, in particular via the drive line 10, andmay further comprise a reservoir for holding a buffer volume ofthe driving uid. The pump maypump driving uid from the reservoir to the bloodpump assembly 1 for contraction ofthe wall structure 2, whereafter the pumped drivinguid mayow back to the reservoir, e.g. passively under pressure from blood in the bloodpump assembly 1 and / or using thepump in reverse. The drive unit 7 is preferably battery powered andmay thus comprise a battery, butmay alternatively or additionally be mains powered. The bloodpumping system 17 may comprise a charger 20 for charging a battery ofthe drive unit 7. In embodiments, including in the shown examples, the bloodpump assembly 1 is congured to be implantable in the mammal, in particular for providing a bloodpumping function in the circulatory system ofthe mammal.Amethod ofproviding a bloodpumping function in the circulatory system ofamammal comprises: providing a bloodpumping system 17 as described herein, in particular with at least the bloodpump assembly 1 beingimplanted in the mammal; uidically connecting the first blood inlet 4 to a vein ofthe mammal and uidically connecting the rst blood outlet 5 to an artery ofthe mammal. The drive unit 7 may be implantable in the mammal as well, in particular at a distance from the bloodpump assembly 1, e.g. at a relatively convenient location in an abdominal cavity ofthe mammal. The charging ofthe drive unit 7 using the charger 20 is then preferably wireless, so that the charger 20 can remain outside the mammal and can there e.g. be connected to mains power. The drive unit 7 may then also be congured for wireless communication with a communication unit outside the mammal, e.g. for receiving monitoring data from the drive unit 7 and / or for adjusting settings ofthe drive unit 7. For robust operation, the drive unit 7 is preferably configured to normally operate independent from such an external communication device. Thus, a controller for thepump of the drive unit 7 is preferably arranged internal to the drive unit 7. In embodiments, including in the shown examples, the drive unit 7 is congured to drive the driving uid in a periodic manner to periodically contract the wall structure 2. Thus, a method ofoperating a bloodpumping system 17 as described herein comprises, using the drive unit 7, driving the driving uid in a periodic manner to periodically contract the wall structure 2. In between contractions, the wall structure 2 is allowed to expandback to an initial conguration, in particular by allowing driving uid toow back to the drive unit 7 to allow the pouches 6 to return to a more attened state. In the initial conguration ofthe wall structure 2 and the more attened state ofthe pouches 6, the pouches may be substantially empty and at. However, in an optional advantageous elaboration, the bloodpumping system 17 may be operated such that the pouches 6 normally remain somewhat filled and thus not completely at in between contractions. In this way, a so-called preload sensitivitymay be promoted in the sense that the volume ofbloodowing into the chamber in between contractions is allowed to be somewhat larger than expected, e.g. larger than in previous cycles, without an undue increase in blood pressure. To illustrate operation ofthe bloodpump assembly 1 and the blood pumping system 17, Figs. 1A-B show a particularly schematic example ofa possible wall structure 2 with pouches 6 for the bloodpump assembly 1. Here, twelve pouches 6 are formed in the mainly cylindrical or conical wall structure 2, although different numbers ofpouches 6 are also possible, and the wall structure 2 need not be rotation symmetric. The pouches 6 surround the rst pump chamber 3 that is boundby the wall structure 2. In Figs. 1A-B, the pouches 6 are elongate, extending with their length direction LD substantially normal to the plane ofthe drawing, with their ends held together at a dead end 2 1 ofthe rst chamber 3. The dead end 21 may be opposite to an end (not shown in Figs. 1A-B) where the rst inlet 4 and the first outlet 5 can be arranged. In Fig. 1A, the pouches 6 are substantially empty and therefore substantially at, i.e. not swollen or bulging, in particular under pressure from blood present (not shown) in the rst chamber 3. Although for clarity the pouches 6 are shown in Fig. 1A to still bulge somewhat, it shall be appreciated that the pouches 6 need not bulge at all ifcompletely empty. By contrast, in Fig. 1B the pouches 6 are substantially full and pressurized with driving uid, and are therefore substantially swollen, i.e. non-at, in particular having a substantially circular cross-sectional shape. Figs. 1A and 1B are drawn on the same scale. It can be seen that in Fig. 1A, due to the pouches 6 being at and therefore relatively wide along the circumferential direction CD, the firstpump chamber 3 is relatively large, in particular having a large size along the circumferential direction and the radial direction RD. By contrast, in Fig. 1B, due to the lled and pressurized pouches 6 being swollen, the width of the pouches 6 along the circumferential direction CD is reduced, resulting in a reduced size ofthepump chamber 3 along the circumferential direction CD and the radial direction RD. Moreover, in Fig. 1B, due to the swelling, the pouches 6 bulge inward in the radial directionRD more than in Fig. 1A, causing a further size reduction ofthe rst pump chamber 3 in Fig. 1B compared to Fig. 1A. Meanwhile, due to the use ofa substantially inextensible material for the pouches 6, the lling ofthe pouches 6 in Fig. 1B does not cause any substantial increase in the size ofthe wall structure 2 in the length directionLD ofthe pouches 6. In this way, it can be understoodhow filling and pressurizing ofthe pouches 6 using the drive unit 7 causes contraction ofthe wall structure 2 and thereby reduction of the volume ofthe first pump chamber 3, thus providing a bloodpumping function: reduction ofthe volume ofthe firstpump chamber 3 drives blood out ofthe rst pump chamber 3 via the rst blood outlet 5, whereafter driving uid may be released from the pouches 6 to allow the rst chamber 3 to expand again while bloodows into the rst pump chamber 3 via the first blood inlet 4, thus completing a pumping cycle that can be repeated over and over.A pulsatile bloodow may thus be provided using a periodic or cyclic filling and emptying, and thus swelling and attening, ofthe pouches 6 to cause periodic or cyclic contraction ofthe wall structure 2. While lling ofthe pouches 6 is preferably actively driven by the drive unit 7, emptying ofthe pouches 6 may be substantially passive, in particular under pressure ofbloodowing into the first pump chamber 3. Nevertheless, in some cases, the drive unit 7 may actively draw driving uid from the pouches 6, for example by operating itspump in reverse. In embodiments, the driving uid is a gaseous driving uid, for example air. It has been found that a gaseous driving uid can provide a level ofcompressibility that, together with the exible nature ofthe wall structure 2, can translate into a beneficial level ofmechanical compliance in the wall structure 2 when the pouches 6 are lled, in particular so as to mimic compliant mechanical behavior of a natural heart to some extent. Advantageously, such compliance may provide a degree ofpassive dampening ofbloodow uctuations, thereby obviating the need for active control elements or electronic sensors in the bloodpump assembly 1. More generally, the bloodpump assembly 1 is preferably a passive assembly, wherein control ofthe pumping is essentially provided by the drive unit 7. Alternatively, the driving uid may be a liquid driving uid. In that case, a desired degree ofcompliance in the wall structure 2 may for example be provided by exibility ofthe wall structure 2, e.g. at one or more pouchless sections 19 thereof, and / or by a passive or active damping arrangement, e.g. in the drive unit 7. An expansion chamber is a possible example ofsuch a passive damping arrangement. In embodiments, including in the shown examples, the number of pouches 6 ofthe series ofpouches 6 is at least three, preferably at least four, more preferably at least ve, even more preferably at least six, for example seven, eight, nine, ten or more. In embodiments, including in the shown examples, the pouches 6 are substantially evenly distributed along the circumferential direction CD, at least along one, two, three or more circumferential sections ofthe wall structure 2, which one or more circumferential sections preferably together extend along at least 70%, 80% or 90% ofthe circumference ofthe wall structure 2. In embodiments, including in the shown examples, adjacent ones ofthe pouches 6 have substantially the same transverse sizes at same levels along their length direction LD. In embodiments, including in the shown examples, the series ofpouches 6 extends along at least 70% ofthe circumferential direction CD ofthe firstpump chamber 3, preferably at least 80%, more preferably at least 90%. In this way, a relatively evenly distributed contraction can be provided along the circumferential direction CD. As illustrative examples, Fig. 7 shows variations ofthe paths of Fig. 2A resulting in different numbers ofpouches, namely ve (N5), seven (N7), nine (N9, corresponding to Fig. 2A), eleven (N11), thirteen (N13) and fteen (N15) pouches. In embodiments, including in the shown examples, the number of pouches 6 ofthe series ofpouches 6 is at most 30, preferably at most 24, more preferably at most 20, even more preferably at most 16, for example 15, 14, 13, twelve, eleven or fewer. In embodiments, including in the shown examples, at least 40% ofthe surface area ofone or more ofthe pouches 6 corresponds to a boundary ofthe rst pump chamber 3, preferably at least 45%, for example about 50% or more. In this way, the volume reducing effect ofthe bulging ofthe pouches 6 can be relatively large, wherein in particular the filledpouches 6 may extend relatively far inward into the rst pump chamber 3 from positions where they are connected to adjacent pouches 6. In embodiments, including in the shown examples, the first blood inlet 4 and the rst blood outlet 5 are arranged next to each other, e.g. parallel to each other, in particular to define substantially opposite blood inow and blood outow directions for the firstpump chamber 3. In embodiments, including in the shown examples, the rst blood inlet 4 and the first blood outlet 5 are arranged at a same end ofthe rst pump chamber 3, in particular wherein at least some ofthe boundaries 9 between the pouches 6 extend substantially directed away from said end ofthe rst pump chamber 3. In embodiments, including in the shown examples, ends of at least some ofthe pouches 6 are held together, e.g. mutually attached, at a dead end 2 1 ofthe firstpump chamber 3, the dead end 2 1 in particular being opposite to the end where the rst blood inlet 4 and the first blood outlet 5 are preferably both arranged. In this way, the mutual arrangement ofthe firstpump chamber 3, the rst blood inlet 4 and the rst blood outlet 5 can be similar to a natural mammalian heart, thereby facilitating its replacement and promoting a relatively natural mechanical behavior. In embodiments, including in the shown examples, the pouches 6 extend, e.g. individually and / or together, from one end ofthe firstpump chamber 3 to an opposite end ofthe rst pump chamber 3, in particular from the dead end 2 1 to the end where the first inlet 4 and the rst outlet 5 are preferably both arranged. In this way, the contraction can be performed relatively evenly and rapidly along the length ofthe firstpump chamber 3, thereby promoting bloodpumping efciency and smoothness ofthe contraction. In embodiments, including in the shown examples, the pouches 6 are formed in the wall structure 2. In this way, material use can be reduced and the pouches 6 can have a relatively well determined arrangement with respect to thepump chamber 3. As a possible alternative, the pouches may be formed in a separate structure that envelops the wall structure. Combinations ofthese alternatives are also possible, i.e. wherein some pouches are formed in the wall structure and some further pouches are formed in the separate structure. In embodiments, including in the examples ofFigs. 2A 5B, at least some ofthe pouches 6 are uidically interconnected. In embodiments, including in the examples ofFigs. 2A 5B, each ofthe pouches 6 is uidically connected to a connector 18, e.g. a single connector 18, for a uidic drive line 10, in particular either directly or via one or more other ones ofthe pouches 6. In this way, driving uid can ow into or out ofone or more ofthe pouches 6 via one or more other ones ofthe pouches 6, obviating the need for separate connections to the drive unit 7 for each pouch 6. In embodiments, including in the examples ofFigs. 2A 3C and 5A-B, uidic passages 8 between adjacent ones ofthe pouches 6 are formed within the wall structure 2. In this way, uidic interconnection ofthe pouches 6 can advantageously be realized within the wall structure 2 itself, obviating the need for separate lines. In embodiments, including in the examples ofFigs. 2A 3C and 5A-B, the uidic passages 8 are formed as local openings 8 in boundaries 9 between the adjacent pouches 6. In this way, the pouches 6 can be efciently uidically interconnected while still being essentially separate pouches 6 in terms ofmechanical behavior. One or more ofsuch local openings 8 can be provided in one or more, e.g. each, ofsuch boundaries 9. The boundaries 9 may be uid impermeable or uid transmissive, e.g. porous. In embodiments, including in the examples ofFigs. 2A 3C and 5A-B, for different pairs of adjacent pouches 6, the local openings 8 are provided at different positions along a length direction LD ofthe pouches 6. In this way, a relatively gradual staggered lling ofsubsequent pouches 6 can be promoted, in particular such that the contraction more closely resembles that ofa natural heart. For example, local openings 8 between subsequent pairs ofpouches 6 may be provided at incremental positions along the length direction LD, so as to promote a somewhat slanted progression ofthe contraction across the wall structure 2, in particular slanted away from the connector 18 and / or towards the first blood outlet 5. In embodiments, including in the examples ofFigs. 2A 3C and 5A-B, the assembly 1 is configured to be uidically connected to the drive unit 7 at one or more but not each ofthe pouches 6, preferably at only one, two or three ofthe pouches 6. In embodiments, including in the shown examples, the assembly 1 is congured to be uidically connected to the drive unit 7 via at least one uidic drive line 10 that is uidically connected or connectable to the series ofpouches 6. In embodiments, including in the shown examples, the bloodpumping system 17 comprises the at least one uidic drive line 10. In embodiments, including in the shown examples, the at least one uidic drive line 10 is a single uidic drive line 10.A connector 18, preferably a single connector 18, for the uidic drive line 10 may be arranged at one ofthe pouches 6 or between two adjacent ones ofthe pouches 6, for example at a position along the length directionLD that is closer to the dead end 2 1 than to the opposite end where the rst blood inlet 4 and the first blood outlet 5 are arranged. In alternative embodiments, multiple drive lines may be provided, e.g. each for a single pouch or group ofpouches. To provide redundancy and / or reduce overall drag losses, one or more pouches may be uidly connected to multiple drive lines. In embodiments, including in the shown examples, the wall structure 2 comprises an inner sheet part 11 and an outer sheet part 12, wherein the pouches 6 comprise respective sections ofthe inner sheet part 1 1 and the outer sheet part 12. In embodiments, including in the shown examples, adjacent ones ofthe pouches 6 are mutually separatedby local mutual attachments ofthe inner sheet part 1 1 and the outer sheet part 12 along boundaries 9 ofthe respective sections ofthe inner sheet part 1 1 and the outer sheet part 12, in particular using heat sealing, gluing, laser welding and / or ultrasonic welding. In embodiments, including in the shown examples, the wall structure 2 comprises a thermoplastic material, for example thermoplastic polyurethane. In this way, the wall structure 2 including the pouches 6 can be constructed in a relatively simple yet effective and customizable manner, in particular from sheet parts that are arranged to mutually overlap and can be attached to each other without a separate adhesive. The inner sheet part 1 1 preferably bounds the rst pump chamber 3, whereas the outer sheet part 12 is preferably outside the first pump chamber 3. Conveniently, the sheet parts 11, 12 may for example be mutually attached while smoothly overlapping and placed on a at surface. The material ofthe outer sheet part 12 may be the same as or different from the material ofthe inner sheet part 1 1. For example, the different sheet parts may be coated differently in view of different hemocompatibility and biocompatibility considerations in the firstpump chamber 3 compared to the outside ofthe bloodpump assembly 1. Thus, a method ofmanufacturing the bloodpump assemblymay comprise: providing two mutually overlapping exible sheet parts 1 1, 12; locally mutually attaching the two sheet parts 1 1, 12 along predefined paths P comprising path sections corresponding to boundaries 9 between adjacent ones ofthe pouches 6; andforming at least part ofthe wall structure 1 from the locally mutually attached exible sheet parts 1 1, 12. With reference to Fig. 2A as example, here, paths P are shown where two mutually overlapping exible sheet parts 1 1, 12 are locally mutually attached. The paths P comprise path sections corresponding to boundaries 9 between adjacent pouches 6. The boundaries 9 are locally interrupted by openings 8 providing passages for driving uid to ow between pouches 6. After the mutual attachment, e.g. using heat sealing, gluing, laser welding or ultrasonic welding, along paths as shown in Fig. 2A, the overlapping sheet parts 1 1, 12 may together be folded over along a fold line F, resulting in a conguration as shown in Fig. 2B in which pouches 6 on the left hand side in Fig. 2A are overlaid over pouches on the right hand side in Fig. 2A. Then, to form the firstpump chamber 3 between the folded over parts, the folded over parts may be attached to each other, again e.g. using heat sealing, gluing, laser welding or ultrasonic welding, along further attachment paths P that are shown in dashed lines in Fig. 2B. Such further attachment paths P may additionally define at least part ofthe first blood inlet 4 and / or the first blood outlet 5, as can be seen in Fig. 2B. After or before completing the attachments, any excess sections ofthe sheet parts 1 1, 12 may be cut off. Alternatively or additionally, part or all ofthe bloodpump assemblymay be manufactured using 3D printing or other additive manufacturing methods, for example. In this way, a particularly high level of design freedom can be provided, further facilitating customization. Further alternatively or additionally, part of all ofthe bloodpump assembly may be manufactured using extrusion and / or casting, for example. In embodiments, including in the examples ofFigs. 4 and 5A-B, the wall structure 2 additionally bounds a secondpump chamber 13 separate from the firstpump chamber 3, wherein the bloodpump assembly 10 comprises a second blood inlet 14 for blood to ow into the secondpump chamber 13 and a second blood outlet 15 for blood toow out ofthe second pump chamber 13. In embodiments, the method ofproviding a blood pumping function comprises uidically connecting the second blood inlet 14 to a further vein ofthe mammal and uidically connecting the second blood outlet 15 to a further artery ofthe mammal. In this way, a same bloodpump assembly 1 and bloodpumping system 17 can provide a dual bloodpumping function, similar to a natural mammalian heart. For example, the second pump chamber 13 may provide a bloodpumping function for a pulmonary circulation ofthe mammal, while the firstpump chamber 3 may provide a bloodpumping function for a systemic circulation ofthe mammal, or vice versa. Options and advantages described herein for the firstpump chamber apply correspondingly to the secondpump chamber 13. Thus, also the secondpump chamber 13 may be regarded as an articial ventricle, so that the bloodpumping system 17 as described hereinmay provide two artificial ventricles, e.g. for a total replacement ofthe mammals natural heart. It shall be appreciated that a dual bloodpumping functionmay alternatively be provided using two separate bloodpump assemblies each having a single pump chamber, for example. Although Fig. 5A shows the second blood inlet 14 arranged next to the first blood inlet 4 and the second blood outlet 15 arranged next to the first blood outlet 5, the mutual arrangement ofinlets and outlets may be different. For example, the second blood inlet may be arranged next to the first blood outlet and the second blood outlet may be arranged next to the first blood inlet. In embodiments, including in the examples ofFigs. 4 and 5A-B, a section ofthe wall structure 2 extends between the firstpump chamber 3 and the secondpump chamber 13, in particular to mutually separate the firstpump chamber 3 and the secondpump chamber 13. In embodiments, including in the example ofFigs. 5A-B, at least some ofthe pouches 6 are arrangedbetween the rst pump chamber 3 and the secondpump chamber 13, in particular in the section ofthe wall structure 2 that mutually separates the firstpump chamber 3 and the secondpump chamber 13. In this way, advantageously, some ofthe pouches 6 can be shared between the first and secondpump chambers 3, 13, providing a relatively efcient combinedpumping function. Moreover, in this way, a stiffness ofthe separating wall section can increase during the contraction through ination ofthe respective pouches 6, promoting a relatively well balanced pumping function in combination with possibly different blood volumes and pressures at the twopump chambers. In embodiments, including in the shown examples, at least one of the first blood inlet 4, the first blood outlet 5, the optional second blood inlet 14 and the optional second blood outlet 15 is provided with a respective non- return valve 16. Similar to heart valves in natural hearts, such non-return valves 16 are preferably passive valves arranged to allow bloodow therethrough in only one direction. Preferably, the non-return valves 16 are exible and / or are free from rigidly interacting elements. In embodiments, including in the examples ofFigs. 3C and 5B, within at least two pairs ofmutually adjacent pouches 6, the respective pouches 6 are mutually spaced apart along the circumferential direction CD, in particular so as to promote a attening ofthe rst pump chamber 3, and optionally the secondpump chamber 13, during contraction. In this way, further volume reduction ofthepump chambers 3, 13 can be obtained upon contraction. In particular, pouch free sections 19 ofthe wall structure 2 between adjacent pouches 6 can locally provide increased exibility while the pouches 6 are lled, allowing other sections ofthe wall structure 2 to approach each other more closely to thereby allow chambers 3, 13 to become relatively at, e.g. compared to a completely non-at conguration as in Fig. 1B. In this respect, it is considered that for a same circumferential size, a more attened chamber will generally have a smaller volume. The pouch free sections are preferably arranged at opposite positions along the circumferential direction CD, in particular at lateral sides ofthe bloodpump assembly 1, e.g. a lateral side where the rst blood inlet 4may be arranged and an opposite lateral side where the rst blood outlet 5 may be arranged. In embodiments, including in the shown examples, the bloodpump assembly 1 is congured to reduce a totalpump chamber volume ofthe first pump chamber 3, and optionally the secondpump chamber 13, during the contraction by an amount that is larger than a total volume increase ofthe pouches 6 during the contraction. It has been found that such a performance can be achieved using congurations ofthe bloodpump assembly 1 as described herein. As explained in the summary section, it is considered that the number ofpouches may be selected to achieve a desired ratio ofblood stroke volume to pouch lling volume in combination with pressure ofthe drive uid. In this way, a particularly efcient bloodpumping system 17 can be provided, in particular with a relatively compact drive unit 7. For example, a relatively high number ofpouches 6 together with a relatively high driving uid pressure can enable a relatively large blood stroke volume at a relatively small pouch filling volume. Alternatively, a lower number of pouches 6 and / or a lower driving uid pressure may be used, in which case the pouch lling volume may be larger than the blood stroke volume. In this respect, the preferably substantially inextensible nature ofthe material of the pouches 6 facilitates efficient handling ofvolumes and pressures as it limits energy dissipation from material elasticity. In embodiments, including in the shown examples except Fig. 8B, the pouches 6: are elongate; have longitudinal axes substantially transverse to the circumferential direction CD; and / or are arranged in a single row along the circumferential direction CD. In alternative embodiments, including in the example ofFig. 8B, the pouches 6: are substantially non- elongate, e.g. substantially square or circular; extend about as much along the circumferential direction CD as transverse thereto; and / or are arranged in multiple rows along the circumferential direction, in particular with each row at a different level along the length direction LD. When comparing Fig. 8B to Fig. 8A, it can be seen that specifics ofthe contraction ofthe wall structure 2 (here illustrated schematically by contracted wall structures 2c) depend on the arrangement ofthe pouches 6. In particular, compared to Fig. 8A, the pouch arrangement of Fig. 8B may result in a more bidirectional contraction, wherein the pump chamber is shortened along the length directionLD in addition to being narrowed transverse to the length direction LD. Meanwhile, contraction transverse to the length directionLD may be somewhat reduced in the variant of Fig. 8B compared to Fig. 8A, e.g. due to boundaries between the pouches 6 taking up more surface area and / or being more constrained. It shall thus be appreciated that many variations are possible also with respect to shapes and arrangements ofthe pouches, enabling a relatively large design freedom with respect to specifics ofthe contraction. In case the mammals natural heart is still partly functional, it is considered that, instead ofreplacing part or all ofthe natural heart, a system comprising a drive unit and a wall structure as described hereinmay be used to reinforce the natural heart in its pumping function. For example, the wall structure with pouches may be arranged as a sleeve around the natural heart, wherein the drive unit is congured to cause contraction of the wall structure synchronized with the contraction ofthe natural heart. In this way, contraction ofthe wall structure can reinforce contraction ofthe natural heart, in particular to help increase cardiac output and / or reduce energy and oxygen demand ofthe natural heart. Compared to the blood pump assembly as described herein, the blood inlets and outlets may then be omitted, and the wall structure need not bound apump chamber, since the blood still ows through the natural heart while the wall structure with the pouches is arranged external to the natural heart. Synchronization of the contraction ofthe wall structure with the contraction ofthe natural heartmay be providing using a suitable control mechanism, e.g. at the drive unit, and / or through physiological interaction between the wall structure and the natural heart. Thus, the present disclosure additionally provides a reinforcing system for reinforcing a bloodpumping by a natural heart ofa mammal, comprising: a exible wall structure congured to surround a natural heart ofthe mammal, wherein a series ofpouches is distributed along a circumferential direction ofthe wall structure is arranged to cause contraction ofthe wall structure upon filling ofthe pouches; and a drive unit congured to drive a drivinguid into the pouches for filling the pouches, in particular synchronously with contraction ofthe natural heart so as to reinforce a bloodpumping by the natural heart. In a method ofproviding a reinforcing of a bloodpumping by a natural heart of a mammal, the wall structure ofthe reinforcing system is arranged to surround the natural heart. It shall be appreciated that options described herein for the blood pumping system can correspondingly be applied to the reinforcing system, with corresponding advantages. Although the invention has been explained herein using examples ofembodiments and drawings, these do not limit the scope ofthe invention as definedby the claims. Within said scope, many variations are possible. For example, two artificial ventricles may be provided in a same mammal using separate bloodpump assemblies for each artificial ventricle, e.g. driven by a same drive unit. The material ofthe wall structure and / or pouches may be coated, may be a composite material such as a laminate or a woven or non-woven ber reinforced material, andmay have a uniform or non-uniform composition across the wall structure and / or pouches. Pouches may be arranged around thepump chamber in multiple concentric layers, e.g. two layers, wherein the layers may ormay not be interconnected, e.g. at one or more boundaries between adjacent pouches. For example, at subsequent boundaries along the circumferential direction, the layers may be alternatingly interconnected and not interconnected. Although not preferred, the bloodpump assemblymay comprise rigid and / or extensible elements, which may ormay not bound part ofthe first and / or secondpump chamber. Further examples have been provided throughout the present disclosure. All such variants are considered included in the scope ofthe invention as defined by the claims. EXPERIMENTALEXAMPLE Fig. 6 shows an experimental measurement result obtained in a laboratory setting using a so-called double mock circulatory loop (MCL) system. TheMCL provided an in-vitro physical simulation ofahuman circulatory system. Two prototypes ofbloodpump assemblies were connected to theMCL as articial ventricles, one for the systemic part and one for the pulmonary part ofthe simulated circulation, with each blood pump assembly being driven via a respective uidic drive line. The prototypes were not tested for biocompatibility, but were at least otherwise congured in accordance with the present invention. Characteristic pressures and volumes were measured over time during the operation ofthe bloodpump assemblies.A stationary simulated circulation performance was observed as characterizedby the followingmeasured parameters: pulse frequency of50 BMP, aortic pressure of 120 / 82 mmHg, pulmonic pressure of47 / 15 mmHg, lling pressures (i.e. blood pressures at the blood inlets of both bloodpump assemblies) of 7mmHg, aortic stroke volume of96 mL, and pulmonary stroke volume of 124 mL. Fig. 6 shows simultaneous portions of measured time series for the aortic pressure (I, solid line) andpulmonary pressure (II, dashed line). LISTOF REFERENCE SIGNS 1. Bloodpump assembly 2. Wall structure 3. Firstpump chamber 4. First blood inlet 5. First blood outlet 6. Pouch 7. Drive unit 8. Fluidic passage between adjacent pouches 9. Boundary between adjacent pouches 10. Fluidic drive line 1 1. Inner sheet part 12. Outer sheet part 13. Secondpump chamber 14. Second blood inlet 15. Second blood outlet 16. Non-return valve 17. Bloodpumping system 18. Connector for uidic drive line 19. Pouchless section ofwall structure 20. Charger 21. Dead end ofrst pump chamber CD. Circumferential direction F. Folding line LD. Length direction ofpouches N5-N15. Variations having 5 to 15 pouches, respectively P. Attachment path RD. Radial direction ofwall structure

Claims

1. Blood pump assembly (1) for blood circulation in a mammal, comprising: a flexible wall structure (2) which a first pump chamber (3) bounded; a first blood inlet (4) to get blood into the first pump chamber (3) let flow; and a first blood outlet (5) to blood the first pump chamber (3) to let out, where one along a circumferential direction (CD) of the first pump chamber (3) divided series of pouches (6) is arranged to contract to cause the wall structure (2) when filling the bags (6), where the assembly (1) is designed to be uide-connected are with a drive unit (7) to a drive unit the bags (6) into float for filling the bags (6).

2. Blood pump assembly according to claim 1, where the bags (6) formed in the wall structure (2).

3. Blood pump combination according to claim 1 or 2, whereby at least some of the pouches (6) are uidiously connected to each other.

4. Blood pump assembly according to claim 3, involving uide passages (8) between adjacent bags (6) of the bags (6) are formed in the wall structure (2).

5. Blood pump assembly according to claim 4, where the uide passages (8) are formed as local openings (8) in borders (9) between adjacent pouches (6), preferably the local openings (8) for different pairs of adjacent pouches (6) are provided at various positions along a longitudinal direction (LD) of the bags (6).

6. Blood pump composition according to one of claims 3-5, where the assembly (1) is arranged to be uidiously connected to the drive unit (7) at one or more, but not each, of the bags (6), at preference in only one, two or three of the bags (6).

7. Blood pump composition according to one of the preceding conclusions, where the assembly (1) is arranged to be u'1'dish connected to the drive unit (7) via at least one uide drive (10) which u'1'dis connected or connectable to the series of pouches (6).

8. Blood pump assembly according to claim 7, where the at least a single uïde driving line (10) is a single u'ide driving line (1).

9. Blood pump composition according to one of the preceding conclusions, where the wall structure (2) has an inner layer part (1 1) and an outer layer part (12) comprises, where the pouches (6) are respective sections of the inner layer part (11) and the outer layer part (12) comprise.

10. Blood pump assembly according to claim 9, where adjacent bags (6) of the bags (6) are separated from each other by local interconnections of the inner layer part (1 1) and the outer layer part (12) along borders (9) of the respective sections. 1 1. Blood pump composition according to one of the preceding conclusions, where the wall structure (2) additionally a second pump chamber (13) bounded which is separated from the first pump chamber (3), where the blood pump assembly (10) a second blood inlet (14), to blood the second to let blood flow into the pump chamber (13), and a second blood outlet (15), to to let blood flow out of the second pumping chamber (13), includes.

12. Blood pump assembly according to claim 1 1, involving a section of the wall structure (2) extends between the first pump chamber (3) and the second pump chamber (13), in particular to the first pump chamber (3) and the second pump chamber (13) to be separated from each other.

13. Blood pump composition according to one of the preceding conclusions, where at least one of the first blood inlet (4), the first blood outlet (5), the optional second blood inlet (14), and the optional second blood outlet (15) is equipped with a respective non-return valve (16).

14. Blood pump composition according to one of the preceding conclusions, where the wall structure (2) includes a thermoplastic material, for example, thermoplastic polyurethane.

15. Blood pump composition according to one of the preceding conclusions, where the blood pump assembly (1) is designed to a total pump chamber volume (V) of the first pump chamber (3), and optionally the second pump chamber (13), to be reduced during contraction with a amount that is greater than a total volume increase of the bags (6) during the contraction.

16. Blood pump composition according to one of the preceding conclusions, where within at least two pairs of mutually adjacent pouches (6), the respective bags (6) are spaced together along the circumferential direction (CD), in particular to create a flatter during contraction become of the first pump chamber (3), and optionally the second pump chamber (13), to promote.

17. Blood pump composition according to one of the preceding conclusions, where the blood pump assembly (1) is designed to be implantable in the mammal, in particular for a blood pumping function in the to provide the circulatory system of the mammal.

18. Blood pump composition according to one of the preceding conclusions, where the pouches (6): are elongated; longitudinal centerlines mainly have perpendicular to the circumferential direction (CD); and / or are arranged in a single row along the perimeter direction (CD).

19. Blood pump composition according to one of the preceding conclusions, where the pouches (6) are formed from a essentially non-elastic material material.

20. Blood pumping system (17) for blood circulation in a mammal, comprising the blood pump assembly (1) according to one of the preceding conclusions and the drive unit (1). 2 1. Blood pumping system according to claim 20, where the blood pump assembly (1) is designed in accordance with at least claim 7 or 8, where the blood pumping system (17) has at least one eclectic drive includes (10).

22. Blood pumping system according to claim 20 or 21, where the driveu'idum is a gaseous driveu'idum, for example air.

23. Blood pump system according to one of conclusions 20-22, where the drive unit (7) is designed to the drive unit in a periodic manner method to drive the wall structure (2) to contract periodically.

24. Procedure for operating a blood pump system (17) according to one of claims 20-23, comprising in a periodic manner driving the drive unit to in a periodic manner the to pull the wall structure (2) together, using the drive unit (7) which is uidily connected to the blood pump assembly (1).

25. Procedure for providing a blood pump function in the circulatory system of a mammal, comprising: - providing a blood pumping system (17) according to one of conclusions 20-23; - the Uididic connection of the first blood inlet (4) to a vein of the mammal and the uidic connection of the first blood outlet (5) with an artery of the mammal; - optionally connect the second blood inlet (14) with a further vein of the mammal and the u'1'disch connecting of the second blood outlet (15) with a further artery of the mammal.

26. Method for making a blood pump assembly (1) according to one of claims 1-19, comprising: - providing two mutually overlapping flexible low parts (11, 12); - locally connecting the two layer sections (1 1, 12) along the pre-designed paths (P) comprising path sections corresponding with boundaries (9) between adjacent pouches of the pouches (6); and - forming at least part of the wall structure (1) of the locally connected flexible layer sections (1 1, 12).

27. Reinforcement system for strengthening a blood pump by a natural heart of a mammal, comprising: - a flexible wall structure designed to create a natural heart of to surround the mammal, whereby a series of pouches is distributed along a The perimeter direction of the wall structure has been applied to allow for contraction. to cause of the wall structure when filling the pouches; and - a drive unit designed to a drive unit the bags in to drive to fill the pouches, in particular synchronously with contraction of the natural heart to pump blood through the to strengthen the natural heart.

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