Microfluidic devices and methods of forming same

Abstract

A method of manufacturing a patient-specific microfluidic device and a patient-specific microfluidic device are provided. The method includes acquiring three-dimensional (3D) information relating to a blood vessel geometry in a region of interest from one or more clinical images associated with the patient, and fabricating a patient-specific microfluidic device using the 3D information. A patient-specific microfluidic device includes a flow channel having a geometry substantially corresponding to a blood vessel geometry in a region of interest.

Description

Technical Field

[0001] This invention generally relates to microfluidic devices and methods of forming such devices. More specifically, this invention relates to microfluidic devices tailored to patient specificities. Background Technology

[0002] Thrombosis (blood clot formation) is a leading cause of cardiovascular disease, including heart attacks and strokes, and is the world's leading cause of death, resulting in an average of two deaths every hour in Australia. Despite recent advances in clinical imaging techniques, thrombosis risk assessment typically relies on invasive digital subtraction angiography—inserting a catheter into an artery and delivering it to the blood vessel. While recent advancements in 4D MRI and phase-contrast technologies have made it difficult to accurately quantify the "Virchow triad" (associated with factors leading to thrombosis) in the cardiovascular or cerebrovascular systems.

[0003] Blood coagulation tests and platelet function analyses have been used to predict thrombosis risk in the past. However, these methods rely on labor-intensive tests, bulky and expensive equipment, and expert interpretation, all of which are unavailable or difficult to obtain in regional and rural healthcare settings.

[0004] In the past, engineered tissue systems, such as bioreactors and vascular network devices, have been developed to simulate various biological conditions in vitro to help healthcare professionals study and test the efficacy of certain drugs before their formal large-scale administration. This involves culturing various cell types and then experimenting on the cultured cells.

[0005] Microfluidic-based bioreactors and microchannels mimicking vascular networks have been used in various forms for drug discovery and development because they can provide more accurate and physiologically relevant model systems to predict and / or test drug-related pharmacokinetic and pharmacodynamic responses. One of the main challenges facing such devices is the need for more complex, physiologically relevant systems to better mimic the structure, physiology, and function of natural biological tissues. This is particularly important and challenging when attempting to screen, test, and / or evaluate therapeutics using engineered tissues. Vascular network microdevices are often relatively standardized, making production costly and time-consuming, especially at scale.

[0006] At least one embodiment of the present invention aims to provide an improved device for predicting thrombotic events in patients. At least one embodiment of the present invention may also aim to provide an improved method for manufacturing such a device. Alternatively, at least one embodiment of the present invention aims to provide useful alternatives to known prior art devices and / or methods.

[0007] References to any prior art in this specification do not imply an acknowledgment or suggestion that such prior art constitutes part of the general knowledge of any jurisdiction, nor do they imply that a person skilled in the art could reasonably expect such prior art to be understood, regarded as relevant, and / or combined with other prior art. Summary of the Invention

[0008] In a first aspect, the present invention provides a method for manufacturing a patient-specific microfluidic device, the method comprising:

[0009] Obtain three-dimensional (3D) information related to the vascular geometry in the region of interest from one or more clinical images associated with a patient;

[0010] The 3D information is used to manufacture patient-specific microfluidic devices, wherein the patient-specific microfluidic devices include flow channels having a geometry that substantially corresponds to the geometry of blood vessels in the region of interest.

[0011] Advantageously, the present invention enables the fabrication of patient-specific microfluidic devices that accurately reflect a patient's vascular system in a specific region of interest. This is achieved by generating flow channels within the microfluidic device based on 3D information derived from one or more clinical images associated with the patient. Thus, the geometry of the flow channels substantially replicates the venous geometry of the patient in the specific region of interest. The patient-specificity of the microfluidic device allows for the collection of more reliable information about the patient, thereby improving the prediction of the patient's prothrombotic predisposition (and thus potentially preventing life-threatening events such as stroke or heart attack). For example, the patient-specific microfluidic device can assess a patient's Virchow's triad, which can provide clinicians with valuable information on more targeted and effective treatment, and even personalized drug efficacy. The microfluidic device can also be used for short- to long-term monitoring of patients with cardiovascular diseases such as stroke, coronary artery stenosis, arteriovenous malformations, and aneurysms.

[0012] Another advantage of the present invention is that it enables the inexpensive manufacture of patient-specific microfluidic devices, including, in some cases, mass production.

[0013] Another advantage of this invention is its ability to manufacture precise microfluidic devices without requiring a core cleanroom facility (including staff support), which can be costly and result in slow turnaround times. Furthermore, this invention is suitable for scaling up manufacturing, allowing for the easy production of multiple microfluidic devices.

[0014] Preferably, the microfluidic device is in the form of a microvascular chip device.

[0015] In one embodiment, one or more clinical images include one or more magnetic resonance imaging (MRI) scans (e.g., magnetic resonance venography (MRV) scans), computed tomography (CT) scans, and any other clinical images containing 3D anatomical information. In one embodiment, one or more clinical images include one or more 2D scans, wherein the 3D information can be obtained or inferred from the one or more 2D scans.

[0016] In one implementation, the method further includes acquiring one or more clinical images related to the patient.

[0017] In one embodiment, acquiring three-dimensional (3D) information includes identifying a region of interest (ROI) from one or more clinical images and converting the one or more clinical images into a 3D vascular profile at least within the ROI. The 3D vascular profile may be generated from a plurality of scatter points associated with the vascular geometry within the ROI. In one embodiment, the 3D vascular profile comprises a continuous surface constructed from the scatter points, thereby generating a surface profile of the vascular geometry within the ROI. In one embodiment, the surface profile of the vascular geometry within the ROI is smoothed using a computer algorithm, such as a surface smoothing algorithm.

[0018] In one embodiment, the method further includes manufacturing a mold based on the 3D information, wherein the mold includes a geometry substantially corresponding to the geometry of blood vessels in the region of interest.

[0019] Preferably, manufacturing the mold includes manufacturing a first mold portion and a second mold portion, wherein the first mold portion includes a geometry substantially corresponding to a first portion of the blood vessel geometry in the region of interest, and the second mold portion includes a geometry substantially corresponding to a second portion of the blood vessel geometry in the region of interest. Preferably, the first and second portions together define a geometry substantially corresponding to the overall blood vessel geometry in the region of interest.

[0020] In one embodiment, the geometry of a first mold portion substantially corresponding to a first portion of the vascular geometry in the region of interest is in the form of a recess extending from the inner surface to the outer surface of the first mold portion. Thus, the first mold portion is in the form of a female mold. In one embodiment, the geometry of a second mold portion substantially corresponding to a second portion of the vascular geometry in the region of interest is in the form of a recess extending from the inner surface to the outer surface of the second mold portion. Thus, the second mold portion is in the form of a female mold. Each corresponding recess of the first mold portion and the second mold portion may include a substantially hemispherical internal profile. However, it should be understood that the precise internal profile of the recess will correspond to the corresponding first and second portions of the vascular geometry in the region of interest. Advantageously, by forming the first mold portion and the second mold portion, each mold portion respectively including a geometry corresponding to a portion of the overall vascular geometry in the region of interest, and utilizing these mold portions in a method of manufacturing a patient-specific microfluidic device, the complex shape of the vascular system can be captured more comprehensively and replicated in the patient-specific microfluidic device.

[0021] In one embodiment, the manufacturing of the mold includes manufacturing the mold using an additive manufacturing process. Preferably, the mold is manufactured using a stereolithography (SLA) 3D printing process. Advantageously, this enables the relatively inexpensive and rapid fabrication of microfluidic devices.

[0022] In one embodiment, manufacturing a first mold portion includes forming a groove extending from an inner surface of the first mold portion to an outer surface of the first mold portion, wherein the groove substantially surrounds a recess. Preferably, the groove at least partially defines a spacer substantially surrounding the recess, wherein the height of the spacer corresponds to the depth of the groove and defines a portion of the first mold portion to be removed. The spacer may be at least partially defined by the groove and the outer periphery of the first mold portion. In one embodiment, manufacturing a second mold portion includes forming a groove extending from an inner surface of the second mold portion to an outer surface of the second mold portion, wherein the groove substantially surrounds a recess. Preferably, the groove at least partially defines a spacer substantially surrounding the recess, wherein the height of the spacer corresponds to the depth of the groove and defines a portion of the second mold portion to be removed. The spacer may be at least partially defined by the groove and the outer periphery of the second mold portion.

[0023] In one embodiment, the method further includes polishing the inner surfaces of the first mold portion and the second mold portion, wherein the polishing includes removing said portion of each of the first mold portion and the second mold portion to form polished inner surfaces of the first mold portion and the second mold portion. Preferably, polishing the inner surfaces of the first mold portion and the second mold portion includes a multi-stage polishing process, including a coarse polishing stage and a fine polishing stage.

[0024] In one embodiment, the method further includes manufacturing a secondary mold from the mold, wherein the secondary mold includes a geometry substantially corresponding to the blood vessel geometry in the region of interest. Preferably, manufacturing the secondary mold includes manufacturing a first secondary mold portion and a second secondary mold portion, wherein the first secondary mold portion includes a geometry substantially corresponding to a first portion of the blood vessel geometry in the region of interest, and the second secondary mold portion includes a geometry substantially corresponding to a second portion of the blood vessel geometry in the region of interest.

[0025] In one embodiment, the method includes manufacturing a first secondary mold from a first mold portion and a second secondary mold from a second mold portion. In one embodiment, the geometry of the first secondary mold portion, substantially corresponding to a first portion of the vascular geometry in the region of interest, is in the form of a protrusion extending outward from the inner surface of the first secondary mold portion. Thus, the first secondary mold portion is in the form of a positive mold. In one embodiment, the geometry of the second secondary mold portion, substantially corresponding to a second portion of the vascular geometry in the region of interest, is in the form of a protrusion extending outward from the inner surface of the second secondary mold portion. Thus, the second secondary mold portion is in the form of a positive mold. Each corresponding protrusion of the first secondary mold portion and the second secondary mold portion may include a substantially hemispherical outer contour. However, it should be understood that the precise outer contour of the protrusion will correspond to the corresponding first and second portions of the vascular geometry in the region of interest. Advantageously, by forming the first secondary mold portion and the second secondary mold portion (each including a geometry corresponding to a portion of the overall vascular geometry in the region of interest), and utilizing these mold portions in a method of manufacturing a patient-specific microfluidic device, the complex shape of the vascular system can be captured more comprehensively and replicated in the patient-specific microfluidic device.

[0026] In one embodiment, the secondary mold is at least partially formed of polydimethylsiloxane (PDMS). In one embodiment, each of the first and second secondary mold portions is at least partially formed of PDMS. In one embodiment, the secondary mold is formed of a PDMS / curing agent mixture, wherein the PDMS / curing agent ratio is between about 1:4 and about 1:6. Preferably, the PDMS / curing agent ratio of the mixture is about 1:5.

[0027] In one embodiment, the first secondary mold portion includes one or more molded spacers projecting from its inner surface. In one embodiment, the second secondary mold portion includes one or more molded spacers projecting from its inner surface. In one embodiment, each of the first and second secondary mold portions includes one or more molded spacers projecting from its inner surface. Preferably, the one or more molded spacers are configured to support glass covers spaced apart from the inner surfaces of the respective first and / or second secondary mold portions. In one embodiment, the one or more molded spacers are integrally formed with their respective secondary mold portions. Alternatively, the one or more molded spacers are attached to the respective secondary mold portions after the secondary mold portions are formed. Preferably, the length of the molded spacer is about 170 μm, measured from the inner surface of the respective first and / or second secondary mold portions. In one embodiment, the one or more molded spacers have a circular outer profile. For example, the one or more molded spacers may be hemispherical or cylindrical. In alternative embodiments, the one or more molded spacers have different outer profiles, such as rectangular.

[0028] In one embodiment, fabricating a patient-specific microfluidic device includes forming the device using a secondary mold, wherein the patient-specific microfluidic device includes a geometry substantially corresponding to the vascular geometry in a region of interest. Preferably, the patient-specific microfluidic device includes a first patient-specific microfluidic device portion and a second patient-specific microfluidic device portion, wherein the first patient-specific microfluidic device portion includes a geometry substantially corresponding to a first portion of the vascular geometry in the region of interest, and the second patient-specific microfluidic device portion includes a geometry substantially corresponding to a second portion of the vascular geometry in the region of interest. In one embodiment, the geometry of the first patient-specific microfluidic device portion substantially corresponding to the first portion of the vascular geometry in the region of interest is in the form of a recess extending from the inner surface of the first patient-specific microfluidic device portion to the outer surface of the first patient-specific microfluidic device portion. In one embodiment, the geometry of the second patient-specific microfluidic device portion substantially corresponding to the second portion of the vascular geometry in the region of interest is in the form of a recess extending from the inner surface of the second patient-specific microfluidic device portion to the outer surface of the second patient-specific microfluidic device portion.

[0029] Preferably, the method includes manufacturing a first patient-specific microfluidic device portion from a first secondary mold portion, and forming a second patient-specific microfluidic device portion from a second secondary mold portion. In one embodiment, forming the first patient-specific microfluidic device portion includes positioning a glass cover on one or more molding spacers of the first secondary mold portion such that the glass cover is spaced apart from the inner surface of the first secondary mold portion, wherein a cavity is formed between the glass cover and the inner surface of the first secondary mold portion. The method may further include injecting a curable material into the cavity and curing the curable material to form the first patient-specific microfluidic device portion. In one embodiment, forming the second patient-specific microfluidic device portion includes positioning a glass cover on one or more molding spacers of the second secondary mold portion such that the glass cover is spaced apart from the inner surface of the second secondary mold portion, wherein a cavity is formed between the glass cover and the inner surface of the second secondary mold portion. The method may further include injecting a curable material into the cavity and curing the curable material to form the second patient-specific microfluidic device portion.

[0030] The curable material can be a PDMS / curing agent mixture. In one embodiment, the PDMS / curing agent mixture has a PDMS / curing agent ratio between about 1:9 and about 1:11. Preferably, the PDMS / curing agent ratio of the mixture is about 1:10.

[0031] In one embodiment, the method further includes forming an inlet channel and an outlet channel in the patient-specific microfluidic device, wherein the inlet channel and the outlet channel are in fluid communication with a flow channel. Preferably, the inlet channel and the outlet channel are formed in one of a first patient-specific microfluidic device portion or a second patient-specific microfluidic device portion. Preferably, the inlet channel is in fluid communication with an upstream end of the flow channel, and the outlet channel is in fluid communication with a downstream end of the flow channel.

[0032] In one embodiment, the method further includes plasma cleaning of the patient-specific microfluidic device. Preferably, the method includes plasma cleaning of a first patient-specific microfluidic device portion and a second patient-specific microfluidic device portion.

[0033] In one embodiment, the method further includes connecting a first patient-specific microfluidic device portion and a second patient-specific microfluidic device portion along their respective inner surfaces, such that the recesses of each respective microfluidic device portion substantially overlap along their longitudinal extent, thereby forming the flow channel having a geometry substantially corresponding to the vascular geometry in the region of interest. In one embodiment, the connection includes bonding. Preferably, the bonding is a covalent bonding. In an alternative embodiment, bonding the first patient-specific microfluidic device portion to the second patient-specific microfluidic device portion includes using an ultraviolet (UV) cured adhesive. In one embodiment, the inner surfaces of the first and second patient-specific microfluidic device portions are filled with UV-curable adhesive, and then the first and second patient-specific microfluidic device portions are carefully aligned under a microscope. Water, for example at 80°C, can then be flowed through the flow channel to remove excess adhesive within the flow channel while maintaining contact between the inner surfaces of the first and second patient-specific microfluidic device portions. In an optional subsequent step, the first and second patient-specific microfluidic device portions are exposed to ultraviolet light to cure the adhesive, thereby bonding the first and second patient-specific microfluidic device portions together. In one embodiment, the connection includes mechanically securing the first patient-specific microfluidic device portion to the second patient-specific microfluidic device portion. For example, the first and second patient-specific microfluidic device portions can be clamped together.

[0034] In one embodiment, manufacturing a patient-specific microfluidic device includes manufacturing the patient-specific microfluidic device using a two-stage molding process, wherein a first stage of the molding process includes manufacturing the secondary mold from a mold, and wherein a second stage of the molding process includes manufacturing the patient-specific microfluidic device from the secondary mold.

[0035] In one embodiment, the method further includes endothelializing the patient-specific microfluidic device.

[0036] In one embodiment, the method of manufacturing a patient-specific microfluidic device includes manufacturing a plurality of patient-specific microfluidic devices, comprising: acquiring three-dimensional (3D) information relating to vascular geometry in a region of interest from one or more clinical images of each of a plurality of patients; and manufacturing a plurality of patient-specific microfluidic devices using the 3D information of each respective patient, wherein each of the plurality of patient-specific microfluidic devices includes a flow channel having a geometry substantially corresponding to the vascular geometry in the region of interest of each respective patient.

[0037] In one embodiment, the method of manufacturing a patient-specific microfluidic device includes manufacturing a plurality of patient-specific microfluidic devices, comprising: acquiring three-dimensional (3D) information relating to vascular geometry in a plurality of regions of interest from one or more clinical images associated with a patient; and using the 3D information to manufacture a plurality of patient-specific microfluidic devices, wherein each of the plurality of patient-specific microfluidic devices includes a flow channel having a geometry substantially corresponding to the vascular geometry in the respective region of interest.

[0038] Advantageously, this type of implementation allows for the production of multiple microfluidic devices through this method, thereby scaling up manufacturing.

[0039] In a second aspect, the present invention provides a patient-specific microfluidic device manufactured using the method of the first aspect of the present invention.

[0040] It should be understood that the features disclosed with respect to the first aspect of the invention also apply to the second aspect of the invention, including different combinations of the disclosed features.

[0041] In a third aspect, the present invention provides a patient-specific microfluidic device comprising a flow channel having a geometry substantially corresponding to the vascular geometry in a patient’s region of interest, the geometry being derived from one or more clinical images associated with the patient.

[0042] Advantageously, the present invention provides a patient-specific microfluidic device that accurately reflects a patient's vascular system in a specific region of interest. This is achieved by providing a flow channel within the microfluidic device, the geometry of which is based on information derived from one or more clinical images associated with the patient. Thus, the geometry of the flow channel substantially replicates the venous geometry of the patient in the specific region of interest. The patient-specificity of the microfluidic device enables the collection of more reliable information about the patient, thereby improving the prediction of the patient's prothrombotic tendency (and thus potentially preventing life-threatening events such as stroke or heart attack). For example, the patient-specific microfluidic device can assess a patient's Virchow's triad, which can provide clinicians with valuable information on more targeted and effective treatment, and even personalized drug efficacy. The microfluidic device can also be used for short- to long-term monitoring of patients with cardiovascular diseases such as stroke, coronary artery stenosis, arteriovenous malformations, and aneurysms.

[0043] In one embodiment, one or more clinical images include one or more of magnetic resonance imaging (MRI) scans (e.g., magnetic resonance venography (MRV) scans), computed tomography (CT) scans, and any other clinical images containing 3D anatomical information. In one embodiment, one or more clinical images include one or more 2D scans, wherein the 3D information can be obtained or inferred from the one or more 2D scans.

[0044] In one embodiment, the patient-specific microfluidic device includes a first patient-specific microfluidic device portion and a second patient-specific microfluidic device portion connected to the first patient-specific microfluidic device portion. The first patient-specific microfluidic device portion includes a geometry substantially corresponding to a first portion of the vascular geometry in the region of interest, and the second patient-specific microfluidic device portion includes a geometry substantially corresponding to a second portion of the vascular geometry in the region of interest. Preferably, the first and second portions together define a geometry substantially corresponding to the overall vascular geometry in the region of interest.

[0045] In one embodiment, the geometry of a first patient-specific microfluidic device portion substantially corresponding to a first portion of the vascular geometry in the region of interest is in the form of a recess extending from the inner surface of the first patient-specific microfluidic device portion to the outer surface of the first patient-specific microfluidic device portion. In one embodiment, the geometry of a second patient-specific microfluidic device portion substantially corresponding to a second portion of the vascular geometry in the region of interest is in the form of a recess extending from the inner surface of the second patient-specific microfluidic device portion to the outer surface of the second patient-specific microfluidic device portion. Each corresponding recess of the first and second patient-specific microfluidic device portions may include a substantially hemispherical internal contour. However, it should be understood that the precise internal contour of the recess will correspond to the corresponding first and second portions of the vascular geometry in the region of interest. Advantageously, by forming the first and second patient-specific microfluidic device portions respectively, each portion comprising a geometry corresponding to a portion of the overall vascular geometry in the region of interest, the complex shape of the vascular system can be captured more comprehensively and replicated in the patient-specific microfluidic device.

[0046] In one embodiment, a first patient-specific microfluidic device portion and a second patient-specific microfluidic device portion are connected along their respective inner surfaces such that the recesses of each corresponding microfluidic device portion substantially overlap along their longitudinal extent, thereby forming the flow channel having a geometry substantially corresponding to the vascular geometry in the region of interest.

[0047] In one embodiment, the patient-specific microfluidic device is formed of a curable material. In one embodiment, each of the first patient-specific microfluidic device portion and the second patient-specific microfluidic device portion is formed of a curable material. The curable material may be a PDMS / curing agent mixture. In one embodiment, the PDMS / curing agent mixture has a PDMS / curing agent ratio between about 1:9 and about 1:11. Preferably, the PDMS / curing agent ratio of the mixture is about 1:10.

[0048] In one embodiment, the patient-specific microfluidic device includes an inlet channel in fluid communication with an upstream end of a flow channel and an outlet channel in fluid communication with a downstream end of the flow channel. Preferably, the inlet channel and the outlet channel are formed in one of a first patient-specific microfluidic device portion or a second patient-specific microfluidic device portion.

[0049] In one embodiment, the patient-specific microfluidic device includes endothelial tissue covering at least a portion of the flow channel. In another embodiment, the endothelial tissue covers at least a portion of a wall that at least partially defines the flow channel. Preferably, the endothelial tissue covers a large portion of the internal contour of the flow channel.

[0050] It should be understood that the features disclosed with respect to the first and second aspects of the present invention also apply to the third aspect of the present invention, including different combinations of the disclosed features.

[0051] As used herein, unless the context otherwise requires, the term "comprise" and its variations, such as "comprising," "comprises," and "comprised," are not intended to exclude further additives, components, integers, or steps.

[0052] Other aspects of the invention, and other embodiments of the aspects described in the foregoing paragraphs, will become apparent from the following description, given by way of example and with reference to the accompanying drawings. Attached Figure Description

[0053] Figure 1 This is a top view of a microfluidic device according to an embodiment of the present invention;

[0054] Figure 2 yes Figure 1 Side view of a microfluidic device;

[0055] Figure 3 It includes Figure 1 A perspective view of the test kit for microfluidic devices;

[0056] Figure 4This is a flowchart of a method for manufacturing a microfluidic device according to an embodiment of the present invention;

[0057] Figure 5 An MRI scan of a specific patient is shown;

[0058] Figure 6 It shows Figure 4 The image processing steps of the method;

[0059] Figure 7 It shows Figure 4 The method involves a two-stage molding process;

[0060] Figure 8 yes Figure 4 Top view of the male mold PDMS chip used in the method;

[0061] Figure 9 This is a top view of the male mold PDMS chip in the second stage of the molding process; and

[0062] Figure 10 A method for manufacturing a plurality of microfluidic devices according to one embodiment of the present invention is shown. Detailed Implementation

[0063] refer to Figure 1 and Figure 2 The image illustrates a patient-specific microfluidic device in the form of a patient-specific microvascular chip device 10. In this embodiment, the patient-specific microvascular chip device 10 is a miniaturized, transparent microfluidic device that enables real-time visualization of the coagulation process as a blood sample moves through a patient-specific flow channel 12 from its upstream end 14 to its downstream end 16. As will become apparent from the following description, the microvascular chip device 10 can provide a low-cost, personalized, and scalable tool for assessing thrombosis.

[0064] The microvascular on-chip device 10 provides an in vitro assessment of a patient's predisposition to thrombosis at a specific location (i.e., in a particular diseased vessel) by simulating the flow of blood through a specific site. An advantage of the microvascular on-chip device 10 is that it can help replicate the complex interactions between blood flow and thrombus under flow disturbances encountered at that location. To this end, the microvascular on-chip device 10 considers two particularly important features to properly simulate possible thrombotic events—(1) patient-specific vascular morphology, and (2) disturbed hydrodynamics.

[0065] As will be described in further detail below, the patient-specific vascular morphology provided by the microvascular on-chip device 10 is provided by fabricating a microvascular on-chip device 10 with patient-specific flow channels 12. The patient-specific flow channels 12 are models of specific blood vessels derived from one or more clinical images of a patient's blood vessels. For example, a microvascular on-chip device 10 with patient-specific flow channels 12 can be generated using one or more CT scans of a patient's cerebral blood vessels, where the patient-specific flow channels 12 simulate, for example, the patient's superior sagittal sinus, sigmoid sinus, coronary artery, or carotid artery. Using a precise representation of the patient's blood vessels in a specific region of interest, it is possible to more accurately simulate blood flow through the vessels. This is because the patient-specific flow channels 12 will reflect any patient-specific vascular structural abnormalities (e.g., stenosis, bifurcation, and aneurysm). The presence of such structural abnormalities will affect the hydrodynamics of blood flow through the vessels, which some known prior art microfluidic devices cannot capture. However, these hydrodynamic effects will be captured by the microvascular on-chip device 10. Therefore, the microvascular on-chip device 10 will provide a more accurate simulation of blood flow through patient-specific blood vessels, thereby enabling better prediction of potential thrombotic events. Furthermore, the patient-specific microfluidic device 10 can also be used for drug screening by moving a blood sample containing a therapeutic dose of drug through a flow channel 12. This allows for more accurate assessment of the efficacy of certain drugs for specific patients, resulting in more personalized and effective treatment.

[0066] like Figure 1 and Figure 2 As best shown, the microvascular chip device 10 is substantially planar in form. The microvascular chip device 10 includes a first microvascular chip device portion 20 and a second microvascular chip device portion 30. The first microvascular chip device portion 20 is substantially cuboid in shape, having an inner surface 22 and an opposing outer surface 24. A recess 26 extends from the inner surface 22 to the outer surface 24. When viewed in cross-section, the recess 26 includes a substantially hemispherical inner contour 27 that defines a substantially hemispherical inner contour of the patient-specific flow channel 12. It should be understood that although the recess 26 is defined as having a substantially hemispherical inner contour 27, in practice the inner contour 27 will have a more complex shape corresponding to the inner contour of a portion of the blood vessel being simulated, in which case, when viewed from... Figure 2 When viewed in the indicated orientation, it will be the “upper part” of the blood vessel. Those skilled in the art will understand that the cross-sectional area of ​​the blood vessel along its length is not constant, which will be reflected by the recess 26, which is formed based on one or more clinical images of the vascular system of the patient in the desired region of interest (e.g., the desired blood vessel).

[0067] Similarly, the second microvascular chip device portion 30 is substantially cuboid in shape, having an inner surface 32 and an opposing outer surface 34. A recess 36 extends from the inner surface 32 to the outer surface 34. When viewed in cross-section, the recess 36 includes a substantially hemispherical inner contour 37 that defines the substantially hemispherical inner contour of the patient-specific flow channel 12. Likewise, it should be understood that while the recess 36 is defined as having a substantially hemispherical inner contour 37, in practice the inner contour 37 will have a more complex shape corresponding to a portion of the external contour of the blood vessel being simulated, in which case, when viewed from... Figure 2 When viewed from the indicated orientation, it will be the "lower part" of the blood vessel. As previously mentioned, the blood vessel does not necessarily have a constant cross-sectional area along its length, which will be reflected by the recess 36.

[0068] Clearly, unlike forming the patient-specific flow channel 12 in the microvascular on-chip device 10 as a single component, the patient-specific flow channel 12 is formed as two parts—a recess 26 is provided on the first microvascular on-chip device portion 20, which provides a substantially hemispherical portion of the vessel's internal contour, and a recess 36 is provided on the second microvascular on-chip device portion 30, which provides another substantially hemispherical portion of the vessel's internal contour. The two substantially hemispherical portions formed by the recesses 26 and 36 together provide the substantially spherical internal contour of the vessel. It is advantageous to form the substantially spherical internal contour of the vessel from two substantially hemispherical internal contours because it allows each substantially hemispherical internal contour to capture finer details of the vessel's internal contour, which is of a fairly complex shape, thus allowing for a more accurate simulation of the overall spherical internal contour of the vessel. In other words, forming the substantially spherical internal contour of the vessel from two separate components allows for a more precise fabrication of the complex anatomy of each individual substantially hemispherical internal contour, thereby enabling a more precise combination of the internal contour of the patient-specific flow channel 12.

[0069] In some embodiments, the first microvascular chip device portion 20 and the second microvascular chip device portion 30 are covalently combined such that the corresponding recesses 26, 36 of each microvascular chip device portion substantially overlap along their longitudinal extent, thereby forming a patient-specific flow channel 12 having an internal contour substantially corresponding to the vascular geometry in the region of interest.

[0070] The microvascular chip device 10 includes an inlet channel 42 extending from the outer surface of one of the first microvascular chip device portions 20 or 30 to its inner surface, such that the inlet channel 42 is in fluid communication with the upstream end 14 of the patient-specific flow channel 12. In the described embodiment, the inlet channel 42 is formed in the first microvascular chip device portion 20 and extends from the outer surface 24 to the inner surface 22. The microvascular chip device 10 also includes an outlet channel 44 extending from the outer surface of one of the first microvascular chip device portions 20 or 30 to its inner surface, such that the outlet channel 44 is in fluid communication with the downstream end 14 of the patient-specific flow channel 12. In the described embodiment, the outlet channel 44 is also formed in the first microvascular chip device portion 20 and extends from the outer surface 24 to the inner surface 22. Preferably, both the inlet channel and the outlet channel are formed on the same microvascular chip device portion, although this is not necessary.

[0071] Inlet channel 42 is configured to receive blood samples and deliver them to patient-specific flow channel 12. To drive the blood sample through patient-specific flow channel 12, the microvascular chip device 10 is equipped with a suitable pump 54. Figure 3 The pump is operably engaged, configured to connect to the outlet channel 44 and drive a blood sample from the upstream end 14 of the patient-specific flow channel 12 to the downstream end 16 of the patient-specific flow channel 12.

[0072] In some embodiments, the microvascular chip device 10 can be used as part of the test kit 50, for example... Figure 3 As shown in the diagram. The test kit 50 includes a portable housing 52 that can suitably house the microvascular chip device 10. In such an embodiment, a pump may be disposed within the housing and operatively associated with a suitable actuator (e.g., button 56) that, when actuated by a user, drives a blood sample through a patient-specific flow channel 12.

[0073] The microvascular chip device 10 can assess Virchow's triad, which describes three major categories of factors believed to lead to thrombosis (thrombus formation): a hypercoagulable state, endothelial dysfunction (endothelial injury), and changes in blood flow (blood flow stagnation). To assess coagulability, the occlusion time and size of the thrombus can be recorded. The location of the thrombus is also recorded based on patient-specific changes in blood flow. To assess the impact of endothelial dysfunction, pseudo-drugs such as PMA or TNF-α are mixed with blood samples to simulate endothelial injury. Changes in occlusion time can then be recorded to assess the effect. For example, the microvascular chip device 10 can accurately assess the blood flow status of a 70-year-old female patient who meets the criteria for Virchow's triad. This involves precisely 3D constructing her vascular geometry, as detailed in Zhao et al., 2023, Advanced Functional Materials, 33, 1-1-13 (DOI: 10.1002 / adfm.202214179), which is incorporated herein by reference. In another example, the hypercoagulable state is not determined by adjusting blood conditions, but by directly testing the patient's blood using a microvascular chip device 10.

[0074] The test kit 50 is envisioned to be used in conjunction with a smart device (e.g., a smartphone) to send post-test images of the microvascular chip device 10 for remote evaluation. Such an application would reduce the need for patients to travel to specialized facilities to undergo testing or obtain results. Therefore, the combination of telemedicine with this embodiment of the invention improves the accessibility of healthcare services, as patients can obtain test results without physically visiting a clinic. The use of smartphones and internet services also ensures high-speed, reliable communication, improving the overall patient experience and outcomes.

[0075] refer to Figure 4 The method 100 for producing a patient-specific microvascular chip device 10 will now be described below.

[0076] To personalize the microvascular chip device 10, it is important to capture and replicate patient-specific anatomy. In step 110, clinical images of the patient's vascular system are acquired. These clinical images can be CT scans, MRI scans (e.g., MRV scans), or any other scan that appropriately captures the patient's vascular system. Multiple scans may be captured to obtain the necessary 3D information. Figure 5In one example shown, 3D anatomy of cerebral blood vessels can be captured, such as the anatomy of the superior sagittal sinus, sigmoid sinus, and / or straight sinus in one or more of the patient's coronal, sagittal, and axial planes. In this example, the microvascular on-chip device 10 can be a microfluidic model simulating the venous geometry of a patient with cerebral venous sinus thrombosis (CVST). It should be understood that the more information captured and used to produce the microvascular on-chip device 10, the more accurate the model, and therefore the more accurate the simulation of blood flow through the blood vessels.

[0077] In step 120, the acquired clinical images are processed in suitable imaging software to generate files suitable for stereolithography (SLA) 3D printing of the patient's vascular system. In this embodiment, image processing involves converting the images into a continuous 3D vascular profile. The vascular geometry is then reconstructed and smoothed using a suitable computer smoothing algorithm. This typically involves forming a continuous surface from scatter points associated with the vascular geometry. The vascular geometry is scaled down to approximately 400 µm in diameter in the software to save material and cost in subsequent molding processes. However, it should be understood that this is merely exemplary and the scaling down can be done to any suitable level depending on material availability, cost constraints, and / or time. Figure 6 An example of a reconstructed sigmoid sinus derived from an MRI scan is provided, showing a narrowing (i.e., stenosis) between its inlet and outlet ends.

[0078] In step 130, files containing the patient's vascular system are used in the SLA 3D printing process to generate two substantially hemispherical female molds 132 of the patient's vascular system (for clarity, Figure 7 (Only one is shown in the image). The inventors discovered that attempting to 3D print a patient's vascular system in a single step leads to inaccurate representation of the vascular system. In particular, the complex shape of the vascular system often means that accurately replicating the complex surface contours of the vascular system in a single step is very difficult. The inventors discovered that the desired level of accuracy can be achieved by generating the patient's vascular system using two substantially hemispherical female molds 132 via SLA 3D printing. These two hemispherical molds 132 are ultimately used in combination to produce the final microvascular chip device 10 in a two-stage molding process, as will be further described below.

[0079] In this embodiment, the two transparent, substantially hemispherical female molds 132 are formed from Formlabs transparent resin (v4), although this is merely exemplary and the two substantially hemispherical female molds may be formed from another material suitable for SLA 3D printing.

[0080] like Figure 7As best shown, the formed vaginal mold includes an elongated recess 134, which, when viewed in cross-section, has a substantially hemispherical profile. The recess 134 extends from the inner surface 136 of the mold 132 toward its outer surface 138. It should be understood that although the recess is defined as having a substantially hemispherical profile when viewed in cross-section, the recess will actually have a complex surface profile corresponding to approximately half of the inner surface profile of the patient's simulated vascular system. The vaginal mold 132 also includes a polished spacer 135, which is formed in the vaginal mold by forming a substantially rectangular notch 137 around the recess 134.

[0081] In step 140, the inner surface 136 of each of the two female molds 132 is polished to make the inner surface 136 of each female mold 132 smooth. Those skilled in the art will understand that a well-known side effect of SLA 3D printing is the effect of light scattering on curved surfaces. Therefore, a polishing process is required to form a precise female mold 132. In this embodiment, a two-stage polishing process is performed. First, a coarse filing stage is performed, for example, using fine sandpaper. Second, a fine filing stage is performed, for example, using a cotton wheel (with a suitable polishing wax). When the polishing spacer 135 is removed, only a generally flat inner surface remains, with an extended recess 134 (see...). Figure 7 At this point, the polishing of the inner surface 136 is complete. Although the polishing process is described as being performed in two stages, this is not necessarily the case. It is conceivable that the polishing process could be performed in other stages, or even in a single stage.

[0082] To further assess whether the polishing process has been successfully completed, the flatness of the inner surface 136 can be inspected using optical sensors or other equipment (such as a scanning electron microscope). Precise tolerances of ±1µm can be achieved in specific areas of the female mold 132.

[0083] In step 150, two PDMS (polydimethylsiloxane) chips 152 are cast from two polished female molds 132 (see...). Figure 7 The PDMS chip 152 is cast by introducing a PDMS / curing agent mixture into a female mold, in this example, the mixture being bonded by a suitable aluminum foil. The PDMS / curing agent mixture may have a PDMS / curing agent ratio between about 1:4 and about 1:6. Preferably, the mixture comprises a PDMS / curing agent ratio of about 1:5. Providing a PDMS / curing agent mixture within this ratio range facilitates the separation of the cast PDMS chip 152 from the female mold 132. In some cases, the PDMS chip 152 may also be treated with silane (which acts as a release agent) to further aid in the separation of the PDMS chip 152 from the corresponding female mold 132.

[0084] The formed PDMS chip 152 will serve as the male mold for the second stage of the two-stage molding process. Each male mold PDMS chip 152 has a substantially hemispherical protrusion 154 extending from the inner surface 156 of each PDMS chip 152. The shape of the protrusion 154 will substantially correspond to the shape of the recess 134 of the female mold 132. The male mold PDMS chip 152 also includes molding spacers 158 protruding from the inner surface of the chip 152. Figure 8 and Figure 9 The molding spacer 158 is integrally molded with the PDMS chip during the molding process of the male PDMS chip. However, it should be understood that the molding spacer 158 can be attached to the male PDMS chip in a separate process. In this embodiment, the molding spacer 158 is in the form of columnar members, wherein each columnar member is arranged adjacent to each corner of the male PDMS chip 152 (a total of 4 columnar members on each chip). However, in other embodiments, the molding spacer 158 may have a circular outer profile to enhance the release of subsequent molding portions. The molding spacer is configured to support a glass cover 159 spaced apart from the male PDMS chip 152 for use in the subsequent molding process described below. The length of the molding spacer 158 may be between about 300µm and 600µm. Preferably, the length of the molding spacer is about 170µm from the inner surface of the chip 152.

[0085] In step 160, the second stage of a two-stage molding process is performed using a male PDMS chip 152. A glass cover plate 159 is supported and spaced apart from the male PDMS chip 152 by placing it on a molding spacer 158. This forms a cavity 157 between the male PDMS chip 152 and the cover plate 159. The PDMS chip 162 is then cast by injection molding. A PDMS / curing agent mixture is injected into the cavity 157 using a syringe, and the mixture is laterally bonded. The PDMS / curing agent mixture may have a PDMS / curing agent ratio between about 1:9 and about 1:11. Preferably, the mixture comprises a PDMS / curing agent ratio of about 1:10. Once the mixture cures, two PDMS chips 162 are produced, each having a recess 164 that defines the negative shape of the desired vascular system. In some cases, the PDMS chip 162 may undergo further silane treatment (which again acts as a release agent) to further aid in the separation of the PDMS chip 162 from the male mold PDMS chip 152 and the cover plate 159. The shape of the molding spacer 158 (as described above) can enhance the release of the PDMS chip 162 from the male mold PDMS chip 152 and the cover plate 159.

[0086] In step 170, an inlet channel and an outlet channel are formed in one of the two formed PDMS chips 162. The inlet channel and outlet channel extend from the outer surface of the PDMS chip 162 to the inner surface of the PDMS chip 162, such that the inlet channel and outlet channel are in fluid communication with the recess 164. The inlet channel extends through the upstream end of the recess, while the outlet channel extends through the downstream end of the recess, as previously discussed. Figure 2 As stated above.

[0087] In step 180, the PDMS chip undergoes plasma cleaning to remove any impurities or contaminants from the surface of the PDMS chip 162.

[0088] In step 190, two PDMS chips 162 are joined together along their respective inner surfaces, in this embodiment by covalent bonding. In this example, a suitable adhesive (e.g., gelatin methacryloyl-GelMA) is applied between the two PDMS chips, and then the PDMS chips are exposed to ultraviolet light to complete the bonding process. Once bonded together, two elongated, substantially hemispherical recesses form a complete elongated, substantially spherical channel configured to allow fluid to pass from its upstream end to its downstream end.

[0089] In step 200, the formed microvascular on-chip device 10 undergoes endothelialization to improve its biocompatibility. In one example, this process involves applying approximately 20 µL of 5x10... 6 A suspension of human umbilical vein endothelial cells (HUVECs) in EGM-2 medium was introduced into a substantially spherical channel through an inlet channel, and the microvascular chip device 10 was incubated for approximately 20 minutes. The microvascular chip device 10 was then inverted and held in this inverted position for approximately 20 minutes to allow the HUVECs to attach to the top of the substantially spherical channel. 200 μL of EGM-2 medium was added to the substantially spherical channel, and it was then statically incubated overnight at 37°C with 5% CO2. Once complete, the endothelialized microvascular chip device 10 was ready for thrombosis testing. The blood sample used was envisioned to be approximately 200 µL, although this is only exemplary. Therefore, the microvascular chip device 10 incorporates live endothelial functionalization and whole blood perfusion to reproduce patient-specific Virchow's triad.

[0090] Although the above method has been described for the production of a single microvascular chip device, each step of the process is applicable to the mass production of multiple microvascular chip devices. (Reference) Figure 10This figure illustrates some steps in the manufacturing process that can be scaled up to provide large-scale production of microvascular chip devices. Specifically, a two-stage molding process (steps 150, 160) can be performed in batches, first assembling various female molds in an appropriate manner. For example, female molds can be arranged in appropriate columns and rows, where specific columns can represent female molds for specific patients, and specific rows can represent female molds for specific blood vessels belonging to a given patient. In other embodiments, a single female mold with multiple recesses appropriately spaced along the female mold can be formed using an SLA 3D printing process.

[0091] The first stage of the molding process can then be performed by casting multiple PDMS chips through the introduction of the PDMS / curing agent mixture into the female mold assembly. This results in a larger PDMS plate, with each individual, substantially hemispherical protrusion extending from the inner surface of the plate. The male mold PDMS plate can then be silane treated to aid in its separation from the assembled female mold. The second stage of the molding process can then be performed using the male mold PDMS plate. This will involve casting multiple PDMS chips by introducing the PDMS / curing agent mixture into the mold cavity of the male mold PDMS plate. Similarly, suitable molding spacers can be used, which can be integrally molded with the male mold PDMS plate or attached to it in a separate process. This results in another PDMS plate having individual, substantially hemispherical recesses extending from the inner surface of the plate to the outer surface of the PDMS plate.

[0092] The PDMS plate with a substantially hemispherical recess can now be appropriately divided into individual chips using a suitable slitting or cutting process. An inlet channel and an outlet channel can then be appropriately formed in one of the two microvascular chip device parts, and the two parts are then joined together to form the final microvascular chip device.

[0093] The large-scale production of multiple microvascular chip devices would significantly reduce manufacturing time and costs.

[0094] Therefore, the microvascular chip device disclosed herein can be used to reproduce Virchow's triad in patients. Using this device, Virchow's triad can be assessed in multiple ways. Blood flow can be monitored by filling the flow channels with fluorescent particles or a blood sample from the patient, and hemodynamics (blood flow patterns) can be monitored using widely available micro-PIV technology. The device can be used in conjunction with inflammatory drugs or physical methods that damage endothelial cells to monitor endothelial dysfunction, and the response of thrombi to endothelial injury can be monitored under a camera. Thrombus formation can be observed using a camera or microscope, and the coagulability of the patient's blood can be assessed based on increases in coagulation factors or calcium in the plasma.

[0095] It should be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more individual features mentioned or obvious from the text or drawings. All these different combinations constitute various alternative aspects of the invention.

Claims

1. A method for manufacturing a patient-specific microfluidic device, the method comprising: Obtain three-dimensional (3D) information related to the vascular geometry in the region of interest from one or more clinical images associated with a patient; The patient-specific microfluidic device is fabricated using the 3D information, wherein the patient-specific microfluidic device includes a flow channel having a geometry substantially corresponding to the vascular geometry in the region of interest.

2. The method of claim 1, wherein the one or more clinical images include one or more of magnetic resonance imaging (MRI) scans, computed tomography (CT) scans, and any other clinical images containing 3D anatomical information.

3. The method of claim 1 or 2, wherein acquiring 3D information includes identifying the region of interest from the one or more clinical images and converting the one or more clinical images into 3D vascular contours at least in the region of interest.

4. The method according to any one of the preceding claims, wherein the 3D blood vessel contour is generated from a plurality of scatter points associated with the blood vessel geometry in the region of interest, and wherein the 3D blood vessel contour comprises a continuous surface constructed from the scatter points, thereby producing a surface contour of the blood vessel geometry in the region of interest.

5. The method of claim 4, wherein a computer algorithm is used to smooth the surface profile of the blood vessel geometry in the region of interest.

6. The method according to any one of the preceding claims, wherein the method further comprises manufacturing a mold based on the 3D information, wherein the mold comprises a geometry substantially corresponding to the geometry of the blood vessel in the region of interest.

7. The method of claim 6, wherein the manufacturing mold includes manufacturing a first mold portion and a second mold portion, wherein the first mold portion includes a geometry substantially corresponding to a first portion of the vascular geometry in the region of interest, and the second mold portion includes a geometry substantially corresponding to a second portion of the vascular geometry in the region of interest, wherein the first portion and the second portion together define a geometry substantially corresponding to the overall vascular geometry in the region of interest.

8. The method of claim 7 or 8, wherein the geometry of the first mold portion substantially corresponding to the first portion of the blood vessel geometry in the region of interest is in the form of a recess extending from the inner surface of the first mold portion to the outer surface of the first mold portion, and the geometry of the second mold portion substantially corresponding to the second portion of the blood vessel geometry in the region of interest is in the form of a recess extending from the inner surface of the second mold portion to the outer surface of the second mold portion, wherein the respective recesses of the first mold portion and the second mold portion each include a substantially hemispherical inner contour, the inner contour generally corresponding to the respective first and second portions of the blood vessel geometry in the region of interest.

9. The method according to any one of the preceding claims, wherein the manufacturing mold comprises manufacturing the mold by an additive manufacturing process, preferably using a stereolithography (SLA) 3D printing process.

10. The method of claim 8 or claim 9, wherein manufacturing the first mold portion includes forming a groove extending from an inner surface of the first mold portion to an outer surface of the first mold portion, wherein the groove substantially surrounds the recess, wherein the groove at least partially defines a spacer substantially surrounding the recess, wherein the height of the spacer corresponds to the depth of the groove and defines a portion of the first mold portion to be removed, and The manufacture of the second mold portion includes forming a groove extending from the inner surface of the second mold portion to the outer surface of the second mold portion, wherein the groove substantially surrounds the recess, wherein the groove at least partially defines a spacer substantially surrounding the recess, wherein the height of the spacer corresponds to the depth of the groove and defines a portion of the second mold portion to be removed.

11. The method according to claim 7 or any one of claims 8 to 11 thereto, further comprising manufacturing a secondary mold from the mold, wherein the secondary mold comprises a geometry substantially corresponding to the vascular geometry in the region of interest.

12. The method of claim 11, wherein manufacturing the secondary mold comprises manufacturing a first secondary mold portion and a second secondary mold portion, wherein the first secondary mold portion comprises a geometry substantially corresponding to a first portion of the blood vessel geometry in the region of interest, and the second secondary mold portion comprises a geometry substantially corresponding to a second portion of the blood vessel geometry in the region of interest, and wherein the method further comprises manufacturing the first secondary mold from the first mold portion and manufacturing the second secondary mold from the second mold portion.

13. The method of claim 12, wherein the geometry of the first secondary mold portion substantially corresponding to the first portion of the blood vessel geometry in the region of interest is in the form of a protrusion extending outward from the inner surface of the first secondary mold portion, and wherein the geometry of the second secondary mold portion substantially corresponding to the second portion of the blood vessel geometry in the region of interest is in the form of a protrusion extending outward from the inner surface of the second secondary mold portion, wherein each of the corresponding protrusions of the first secondary mold portion and the second secondary mold portion includes a substantially hemispherical outer contour corresponding to the corresponding first and second portions of the blood vessel geometry in the region of interest.

14. The method according to any one of claims 11 to 13, wherein the secondary mold is at least partially formed of polydimethylsiloxane (PDMS), wherein preferably the secondary mold is formed of a PDMS / curing agent mixture with a PDMS / curing agent ratio between about 1:4 and about 1:

6.

15. The method according to claim 12 or any one of claims 12 to 14 thereto, wherein the first secondary mold portion includes one or more molding spacers projecting from its inner surface, and / or wherein the second secondary mold portion includes one or more molding spacers projecting from its inner surface. The one or more molding spacers are configured to support glass covers spaced apart from the inner surfaces of the respective first secondary mold portion and / or second secondary mold portion.

16. The method according to any one of claims 16 to 23, wherein manufacturing the patient-specific microfluidic device comprises forming the patient-specific microfluidic device from the secondary mold, wherein the patient-specific microfluidic device comprises a geometry substantially corresponding to the vascular geometry in the region of interest.

17. The method of claim 7 or any one of claims 8 to 16 thereto, wherein the patient-specific microfluidic device comprises a first patient-specific microfluidic device portion and a second patient-specific microfluidic device portion, wherein the first patient-specific microfluidic device portion comprises a geometry substantially corresponding to a first portion of the vascular geometry in the region of interest, and the second patient-specific microfluidic device portion comprises a geometry substantially corresponding to a second portion of the vascular geometry in the region of interest, and The geometry of the first patient-specific microfluidic device portion, which substantially corresponds to the first portion of the vascular geometry in the region of interest, is in the form of a recess extending from the inner surface of the first patient-specific microfluidic device portion to the outer surface of the first patient-specific microfluidic device portion, and the geometry of the second patient-specific microfluidic device portion, which substantially corresponds to the second portion of the vascular geometry in the region of interest, is in the form of a recess extending from the inner surface of the second patient-specific microfluidic device portion to the outer surface of the second patient-specific microfluidic device portion.

18. The method of claim 17, which is dependent on claim 12, further comprising manufacturing the first patient-specific microfluidic device portion from the first secondary mold portion, and forming the second patient-specific microfluidic device portion from the second secondary mold portion.

19. The method according to claim 17 or 18, which is dependent on claim 15, wherein forming the first patient-specific microfluidic device portion and the second patient-specific microfluidic device portion comprises positioning a glass cover on one or more molding spacers of the respective first secondary mold portion and the second secondary mold portion such that the glass cover is spaced apart from the inner surfaces of the respective first secondary mold portion and the second secondary mold portion, wherein a mold cavity is formed between the glass cover and the inner surfaces of the respective first secondary mold portion and the second secondary mold portion, and The method further includes injecting a curable material into a corresponding mold cavity to cure the curable material, thereby forming the first patient-specific microfluidic device portion and the second patient-specific microfluidic device portion.

20. The method of claim 19, wherein the curable material is a PDMS / curing agent mixture, wherein preferably the PDMS / curing agent mixture has a PDMS / curing agent ratio between about 1:9 and about 1:

11.

21. The method according to any one of the preceding claims further comprises forming an inlet channel and an outlet channel in the patient-specific microfluidic device, wherein the inlet channel and the outlet channel are in fluid communication with the flow channel.

22. The method of claim 21 or any one of claims 19 to 20 thereof, further comprising connecting the first patient-specific microfluidic device portion and the second patient-specific microfluidic device portion along their respective inner surfaces such that the recesses of each respective microfluidic device portion substantially overlap along their longitudinal extent, thereby forming the flow channel having a geometry substantially corresponding to the vascular geometry in the region of interest.

23. The method according to any one of the preceding claims further includes endothelializing the patient-specific microfluidic device.

24. A patient-specific microfluidic device manufactured using the method according to any one of claims 1 to 23.

25. A patient-specific microfluidic device comprising a flow channel having a geometry substantially corresponding to a vascular geometry in a region of interest of a patient, the geometry being derived from one or more clinical images associated with the patient.

26. The apparatus of claim 25, wherein the one or more clinical images comprise one or more of magnetic resonance imaging (MRI) scans, computed tomography (CT) scans, and any other clinical images containing 3D anatomical information.

27. The apparatus of claim 25 or 26, wherein the patient-specific microfluidic device comprises a first patient-specific microfluidic device portion and a second patient-specific microfluidic device portion connected to the first patient-specific microfluidic device portion, wherein the first patient-specific microfluidic device portion comprises a geometry substantially corresponding to a first portion of the vascular geometry in the region of interest, and the second patient-specific microfluidic device portion comprises a geometry substantially corresponding to a second portion of the vascular geometry in the region of interest, wherein the first portion and the second portion together define a geometry substantially corresponding to the overall vascular geometry in the region of interest.

28. The apparatus of claim 27, wherein the geometry of the first patient-specific microfluidic device portion substantially corresponding to the first portion of the vascular geometry in the region of interest is in the form of a recess extending from the inner surface of the first patient-specific microfluidic device portion to the outer surface of the first patient-specific microfluidic device portion, and wherein the geometry of the second patient-specific microfluidic device portion substantially corresponding to the second portion of the vascular geometry in the region of interest is in the form of a recess extending from the inner surface of the second patient-specific microfluidic device portion to the outer surface of the second patient-specific microfluidic device portion, wherein the respective recesses of the first patient-specific microfluidic device portion and the second patient-specific microfluidic device portion are each capable of including a substantially hemispherical inner contour, the inner contour generally corresponding to the respective first and second portions of the vascular geometry in the region of interest.

29. The device of claim 28, wherein the first patient-specific microfluidic device portion and the second patient-specific microfluidic device portion are connected along their respective inner surfaces such that the recesses of each respective microfluidic device portion substantially overlap along their longitudinal extent, thereby forming the flow channel having a geometry substantially corresponding to the vascular geometry in the region of interest.

30. The device according to any one of claims 25 to 29, wherein the patient-specific microfluidic device comprises an inlet channel in fluid communication with an upstream end of the flow channel and an outlet channel in fluid communication with a downstream end of the flow channel; and / or The patient-specific microfluidic device includes endothelial tissue covering at least a portion of the flow channel, wherein the endothelial tissue covers at least a portion of the wall, the wall at least partially defining the flow channel.

Images