Multiple layer medical balloon

Abstract

A medical device includes an elongated body configured to be introduced into a blood vessel and an expandable structure at a distal portion of the elongated body. The expandable structure includes a first layer having a first Shore D hardness, a second layer having a second Shore D hardness and positioned radially outward of the first layer, and a third layer having a third Shore D hardness and positioned radially outward of the first layer and the second layer. In some examples, the third Shore D hardness is less than or equal to the first Shore D hardness and less than the second Shore D hardness. The third layer can be configured to receive a stent and / or one or more sensors such that the stent and / or the one or more sensors are at least partially embedded in the third layer.

Description

Docket No.: A0012639W001 / 1241-321W001MULTIPLE LAYER MEDICAL BALLOON

[0001] This application claims priority to, and the benefit of, U.S. Provisional Application No. 63 / 692,343, filed September 9, 2024, and entitled “MULTIPLE LAYER MEDICAL BALLOON,” the entire contents of which is incorporated herein by reference.TECHNICAL FIELD

[0002] This disclosure relates to medical catheters.BACKGROUND

[0003] Medical devices including stents, such as bare metal stents or drug-coated stents, may be delivered to passages of the body (e.g., blood vessels, ureters and other hollow structures) and expanded to hold open the passage of the body. In some examples, stents are delivered to narrowed arteries to facilitate increased blood flow through the artery. Catheters may be used to deliver and / or expand stents at locations of interest.SUMMARY

[0004] This disclosure describes medical device systems including catheter systems used during a medical procedure, such as a percutaneous coronary intervention (PCI) procedure. Such medical procedures can include balloon angioplasty, stent delivery and / or stent expansion via a minimally invasive procedure using a catheter (e.g., stent delivery systems as well as other catheters configured to expand a stent). In some examples, the medical devices described herein are used for stent delivery and / or stent expansion. In some examples, the medical device systems described herein include catheter systems configured to both expand a balloon and / or a stent against a blood vessel wall as well as determine one or more clinically relevant parameters, measurements, or indices related to the blood vessel or the stent. For example, in some examples, the medical devices system described herein can include sensors and relevant processing circuitry configured to measure and determine relevant parameters about the balloon, the stent, and / or the blood vessel.

[0005] During manufacturing of stent delivery systems, a stent is crimped onto a balloon such that the stent is transformed to a radially compressed configuration around a portion of the balloon. The crimping force used to crimp the stent onto the balloon can create frictional engagement between the stent and the balloon such that the stent resists movement relative to balloon, e.g., as the stent is being navigated through vasculature of a patient to a target location. In some cases, a higher crimping force can correspond to a greater frictional engagementDocket No.: A0012639W001 / 1241-321W001 between the stent and the balloon. Greater frictional engagement can enable the balloon to more easily retain the stent such that the probability of stent movement relative to the balloon (e.g., movement axially and or circumferentially relative to the balloon) is reduced or even eliminated. However, in some cases, the crimping force is selected to minimize alteration of the balloon material (e.g., alteration that can create holes and / or other structural alterations that could otherwise impact the performance of the balloon, such as the ability to inflate). In some cases, minimizing alteration of the balloon material can be achieved via a relatively lower crimping force. Thus, crimping of a stent onto a balloon requires a suitable process using a crimping force that creates a suitable frictional engagement between the balloon and the stent without significantly altering the balloon material.

[0006] The devices and techniques described herein can facilitate stent retention on medical balloons while simultaneously reducing impact (e.g., physical alteration) of portions of the balloon onto which a stent is crimped. For example, the balloons described herein can include at least one layer that is configured to be relatively softer than other radially adjacent layers such that a stent at least partially embeds into the relatively softer layer during the crimping process. However, the devices described herein can be configured such that the crimping process structurally alters some layers (e.g., the radially outermost layer) without impacting other radially adjacent layers.

[0007] Additionally and / or alternatively, the devices and techniques described herein can enable one or more sensors to be carried by the balloon without significantly increasing the greatest cross-sectional dimension (e.g., diameter) of the balloon. For example, one or more layers of the balloon (e.g., the relatively less hard outermost layer) can include structural features (e.g., pockets) configured to received and / or retain one or more sensors. Such sensors can be configured to facilitate determination of clinically relevant features related to PCI procedures (e.g., parameters related to lesions, stent expansion and / or apposition, and / or the like).

[0008] In the examples described herein, a medical device system includes a medical device such as a catheter system (e.g., a balloon catheter system). The catheter system includes an elongated body and an expandable structure (e.g., a balloon) at a distal portion of the elongated body. In some examples herein, the balloon includes at least one layer (e.g., a layer of material), such as a radially outermost layer, that is relatively less hard (e.g., has a relatively lower Shore D hardness) than other radially adjacent (e.g., more radially inward) layers. In some examples, a radially outmost layer that is relatively less hard enables a stent and / or one or more sensors to be at least partially embedded and / or otherwise retained by the third layer, such that the stent and / or the one or more sensors is retained on the balloon (e.g., such as during navigation of the expandable structure as well as the balloon and / or the one or more sensors through vasculature ofDocket No.: A0012639W001 / 1241-321W001 a patient). In examples in which the balloon is used in a stent delivery and / or stent expansion procedure, the outer layer of the balloon can be configured to help retain the stent on the balloon (e.g., because at least some portions of the stent are at least partially embedded in the outer layer of material and frictionally engaged, which may reduce a likelihood of the stent moving axially or rotationally relative to the balloon). In some examples in which one or more sensors are carried by the balloon, at least the radially outmost layer can include structural features (e.g., one or more pockets) configured to receive the one or more sensors, such that the balloon can carry one or more sensors without substantially increasing the widest cross-sectional dimension of the balloon.

[0009] In the examples described herein, the balloon includes multiple layers of material (e.g., multiple radially adjacent layers comprising different materials having different material properties). In some examples herein, a balloon includes at least a first layer having a first Shore D hardness, a second layer having a second Shore D hardness and positioned radially outward of the first layer, and a third layer having a third Shore D hardness and positioned radially outward of the first layer and the second layer. In some examples, the third Shore D hardness of the third layer (e.g., the radially outermost layer) is equal to or less than the first Shore D hardness of the first layer and less than the second Shore D hardness of the second layer. In some examples, the second Shore D hardness of the second layer (e.g., the radially middle layer that is radially outside of the first layer and radially inside of the third layer) is greater than the first Shore D hardness of the first layer and the third Shore D hardness of the third layer. The relatively greater Shore D hardness of the second layer can enable the balloons described herein to have suitable mechanical properties (fatigue resistance and / or burst pressure), which can enable the balloon to apply a suitable expansion force on a stent and / or a vessel wall (e.g., including a radial force against plaque). In some examples, the first layer having the first Shore D hardness contributes to the suitable mechanical properties (fatigue resistance and / or burst pressure) of the balloon (e.g., to enable the balloon to apply a suitable expansion force on a stent and / or a vessel wall).

[0010] The relatively lower third Shore D hardness of the third layer (e.g., which may be a radially outermost layer) can facilitate relatively better retention of the stent on the balloon (e.g., as compared to other balloons including an outermost layer with a relatively higher Shore D hardness). For example, because the balloons described herein include multiple layers with a radially outermost layer having a relatively lower Shore D hardness, a relatively greater crimping force may be used to crimp a stent onto the balloon which may cause the stent to embed into the radially outmost layer and facilitate relatively greater stent retention. Because other layers (e.g., other, more radially inward layers) of the balloon are minimally impacted during the crimping process (e.g., as least compare to the outermost layer), such layers can enable the balloon toDocket No.: A0012639W001 / 1241-321W001 maintain a suitable burst pressure and / or suitable fatigue resistance during use. Because the radially outermost layer of the balloon may become mechanically compromised (e.g., by design) during the crimping process in which the stent is at least partially embedded in the radially outermost layer, the radially outermost layer can be considered a “sacrificial” layer.

[0011] While the balloons described herein include a relatively less hard radially outer layer of material, other layers (e.g., other radially adjacent layers, such as layers radially inward of the radially outermost layer) can be configured to enable the expandable structure (e.g., balloon) to maintain a suitable burst pressure, fatigue resistance, and / or other relevant properties. For example, the inner layers can include a relatively higher Shore D hardness as compared to the outermost layer, which can enable the balloon to have a suitable burst pressure, fatigue resistance, and / or have suitable expansion properties (e.g., expansion properties under pressure, such as minimal diameter growth above a given rated pressure). Because the radially inward layers (e.g., radially inward as compared to a radially outermost layer) may contribute less to retaining a stent on the ballon (e.g., at least compared to a radially outermost layer), the use of relatively higher durometer materials for such radially inward layers is enabled.

[0012] Although the balloons described herein include multiple radial layers (e.g., at least two layers, such as three or more layers), the expandable structures can define a comparable and / or a relatively lower wall thickness as compared to other expandable structures (e.g., balloons) used for similar medical procedures, such as stent delivery and / or stent expansion. In some examples, the expandable structures described herein define a wall thickness (e.g., double wall thickness measuring all radially adjacent layers) that is equal to or less than typical balloons used in similar procedures (e.g., such as stent delivery). Such relatively lower double wall thickness (DWT) values of the expandable structures described herein can enable the expandable structures to navigate through torturous anatomy and / or cross narrow portions within vasculature of a patient (e.g., while simultaneously facilitating stent retention and / or the ability to have one or more sensors at least partially embedded in the balloon).

[0013] In some examples, one or more portions of the medical device (e.g., such as the expandable structure) are configured to expand against a wall of a vessel and / or stent, e.g., to expand the stent against the vessel wall. For example, the catheter systems described herein can be configured for use in a pre-dilation expansion procedure (also referred to herein as a predilatation procedure), in a stent delivery and / or stent expansion procedure, and / or a post-dilation expansion procedure (also referred to herein as a post-dilatation procedure). Additionally or alternatively, in some examples, the expandable structures described herein can be configured for use in a plain old balloon angioplasty (POBA) procedure (e.g., to compress and / or soften plaque).Docket No.: A0012639W001 / 1241-321W001

[0014] In some examples herein, in which one or more portions of the medical device (e.g., such as the expandable structure) include one or more sensors, the medical device system can be used to measure, determine, and / or output one or more relevant medical parameters. For example, the one or more sensors can enable the medical device system to measure and / or determine parameters associated with stent delivery and / expansion (e.g., such as a level of stent apposition against a vessel wall and / or a level of stent expansion). In some examples, the one or more sensors can enable the medical device system to measure and / or determine parameters associated with lesion and / or plaque morphology (e.g., such as determining a lesion classification, which can include calcific, fatty, fibrous, or the like).

[0015] In examples where the medical device includes one or more sensors carried by the expandable structure, the sensor may be physically and communicatively coupled to processing circuitry of the medical device system. The processing circuitry can be configured to receive and process signals to determine one or more measures, indices, parameters related to the balloon, the blood vessel, or the stent, e.g., while the distal portion of the catheter system is introduced (e.g., inserted) into the blood vessel of the patient. The measures, indices, parameters related to the balloon, the blood vessel, or the stent can include force values and / or pressure values based on forces and / or pressure applied by a stent or a blood vessel wall against the expandable structure (e.g., as measured by the one or more sensors carried by the expandable structure), as well as physiological information of the patient, including lesion morphology. In some examples, the processing circuitry is configured to determine deformation and / or expansion of various portions of the balloon (e.g., by measuring strain via strain sensors). In this way, a clinician may be enabled to receive indications of measures, indices, parameters related to the balloon, the blood vessel, or the stent and / or indications of the physiological information with the same device the clinician would use to expand the blood vessel and / or would use to deliver and / or expand the stent.

[0016] In some examples described herein, the processing circuitry is configured to determine and / or generate, for output to a user (e.g., a clinician), relevant information of and / or relating to parameters (e.g., force and / or pressure) measured and / or detected by the one or more sensors. In some examples, the processing circuitry is configured to determine a map of force values and / or pressure values (e.g., a map over a surface of the expandable structure and / or the stent). In some examples, the processing circuitry is configured to generate, for output (e.g., on a user interface), the map of force values and / or pressure values. In some examples, the processing circuitry is configured to determine and / or generate for output, one or more locations of malapposition of the stent against the blood vessel wall. In some examples, the processing circuitry is configured to determine and / or generate for output, one or more degrees of appositionDocket No.: A0012639W001 / 1241-321W001 of the stent against the blood vessel wall (e.g., adequately apposed, semi-adequately apposed, inadequately apposed, and / or malapposed). In some examples, the processing circuitry is configured to determine and / or generate for output, a shape (e.g., a geometry, including a cross- sectional shape at one or more locations) of the balloon and / or the stent based on the one or more force values and / or pressure values.

[0017] Such information can enable a user (e.g., a clinician) to make clinically relevant decisions. For example, such information determined via sensors can enable a clinician to target and / or selectively expand particular portions of the stent (e.g., a distal portion, a proximal portion, or the like) to improve the apposition of the stent against the blood vessel wall at such portions. In some examples, the processing circuitry is configured to determine and / or generate for output, a shape (e.g., a geometry, including a cross-sectional shape at one or more locations) of a blood vessel (e.g., including a geometry and / or shape of a lesion) based on the one or more force values and / or pressure values. Such information can enable a user (e.g., a clinician) determine whether clinical intervention is needed (e.g., whether to compress the lesion, which can include plaque, via an angioplasty or stenting procedure). Such information can enable a user (e.g., a clinician) to select an appropriate stent (e.g., e.g., a sizing, including length and diameter of one or more stent), and / or make another clinically relevant decision.

[0018] In some examples, a medical device includes an elongated body configured to be introduced into a blood vessel of a patient; and an expandable structure at a distal portion of the elongated body, the expandable structure including: a first layer having a first Shore D hardness; a second layer having a second Shore D hardness and positioned radially outward of the first layer, the second Shore D hardness greater than the first Shore D hardness; and a third layer having a third Shore D hardness and positioned radially outward of the first layer and the second layer, the third Shore D hardness less than or equal to the first Shore D hardness and less than the second Shore D hardness, wherein: the third layer is configured to receive a stent such that the stent is at least partially embedded in the third layer, and / or the third layer is configured to receive one or more sensors such that the one or more sensors are at least partially embedded in the third layer.

[0019] In some examples, a method includes introducing a medical device into vasculature of a patient, the medical device includes an elongated body configured to be introduced into a blood vessel of the patient, and an expandable structure at a distal portion of the elongated body, the expandable structure including: a first layer having a first Shore D hardness, a second layer having a second Shore D hardness and positioned radially outward of the first layer, the second Shore D hardness greater than the first Shore D hardness, and a third layer having a third Shore D hardness and positioned radially outward of the first layer and the second layer, the third Shore DDocket No.: A0012639W001 / 1241-321W001 hardness less than or equal to the first Shore D hardness and less than the second Shore D hardness, wherein: the third layer is configured to receive a stent such that the stent is at least partially embedded in the third layer, and / or the third layer is configured to receive one or more sensors such that the one or more sensors are at least partially embedded in the third layer; and advancing the medical device until the expandable structure is at or near a target location in the vasculature of the patient.

[0020] In some examples, a medical device system includes an elongated body configured to be introduced into a blood vessel of a patient; an expandable structure at a distal portion of the elongated body, the expandable structure including: a first layer having a first Shore D hardness; a second layer having a second Shore D hardness and positioned radially outward of the first layer, the second Shore D hardness greater than the first Shore D hardness; and a third layer having a third Shore D hardness and positioned radially outward of the first layer and the second layer, the third Shore D hardness less than or equal to the first Shore D hardness and less than the second Shore D hardness, one or more sensors at least partially embedded in the third layer; and one or more conductor wires at least partially embedded in the third layer and electrically coupled to the one or more sensors, wherein the third layer defines a pocket configured to receive the one or more sensors.

[0021] The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF DRAWINGS

[0022] FIG. 1 A is a schematic illustration of an example medical device system including a catheter system.

[0023] FIG. IB is a schematic illustration of an example distal portion of the catheter system of FIG. 1A including an expandable structure shown along with sensors and a stent.

[0024] FIG. 1C is a schematic illustration including a cross-sectional view of the example distal portion of the catheter of FIG. IB.

[0025] FIG. ID is a graph illustrating double wall thickness values for different configurations of example balloons discussed in this disclosure.

[0026] FIG. IE is a graph illustrating burst pressure values for different configurations of example balloons discussed in this disclosure.

[0027] FIG. IF is a graph illustrating hoop stress values for different configurations of balloons discussed in this disclosure.Docket No.: A0012639W001 / 1241-321W001

[0028] FIG. 2 is a functional block diagram illustrating some components of the catheter system of FIG. 1A.

[0029] FIG. 3 A is a schematic illustration of an example expandable structure defining a pocket configured to receive a sensor and / or another therapeutic element.

[0030] FIG. 3B is a schematic illustration of the example expandable structure of FIG. 3 A having at least one sensor within the pocket defined by the expandable structure.

[0031] FIG. 3C is a schematic illustration including an example cross-sectional view of a portion of the example expandable structure of FIG. 3B.

[0032] FIG. 3D is a schematic illustration including an example cross-sectional view of a portion of the example expandable structure of FIG. 3B.

[0033] FIG. 3E is a schematic illustration including an example cross-sectional view of a portion of the example expandable structure of FIG. 3B.

[0034] FIG. 4A is a schematic illustration of an example extruded tube with one or more conductor wires extending within the extruded tube.

[0035] FIG. 4B is a schematic illustration of an expandable structure formed from the extruded tube of FIG. 4A with one or more conductor wires electrically connected to a sensor that is carried by the expandable structure.

[0036] FIG. 4C is a schematic illustration including a cross-sectional view of the example extruded tube of FIG. 4A.

[0037] FIG. 4D is a schematic illustration including a cross-sectional view of the example expandable structure of FIG. 4B.

[0038] FIG. 5A is a schematic illustration of an example expandable structure having a plurality of conductive elements carried by at least one layer of the expandable structure.

[0039] FIG. 5B is a schematic illustration of the example expandable structure of FIG. 5 A having one or more of the conductive elements joined to form one or more sensors.

[0040] FIG. 6 is a flow diagram illustrating an example technique for introducing and advancing a medical device according to the examples of this disclosure.

[0041] Like reference characters denote like elements throughout the description and figures.DETAILED DESCRIPTION

[0042] This disclosure describes devices, systems, and methods relating to medical device systems, including catheter systems used during percutaneous coronary intervention (PCI) procedures. An example PCI procedure includes balloon angioplasty and / or stent placement in a hollow anatomical body (e.g., a blood vessel). Angioplasty balloons and / or stents are configured to expand radially outward at a treatment location, such as to open up a narrowed portion of aDocket No.: A0012639W001 / 1241-321W001 blood vessel, which may include an abnormal narrowing or blockage of the blood vessel. During an angioplasty or stent placement procedure, a clinician may insert a first balloon catheter into a blood vessel and inflate the balloon to open up a blood vessel prior to placement of a stent (e.g., as may be referred to herein as a pre-dilation procedure). The clinician may then deliver the stent on a second balloon catheter to the treatment location and expand the stent to further open the narrowed portion of the blood vessel. After placement and expansion of the stent the clinician may further expand the stent or ensure uniform expansion with a third catheter (e.g., as may be referred to herein as a post-dilation procedure).

[0043] In some examples, clinicians may use feedback from various imaging and / or measurement modalities to determine whether a stent has been sufficiently expanded, or whether further expansion is warranted. For example, clinicians may receive feedback from imaging modalities or other measurement tools to determine whether a stent has been sufficiently expanded, such as after initial delivery and initial expansion and / or after a post-dilation expansion performed with a different catheter. Information about stent deployment and / or expansion may correlate with potential complications, including stent migration, dissection, and longer-term complications such as late stent thrombosis, in-stent restenosis, etc. In some cases, where a clinician receives feedback that a stent has not been adequately expanded and / or a stent is not adequately apposed against a blood vessel wall, a clinician may decide to further expand a stent, such to increase the clinical efficacy of the stent.

[0044] While the imaging and / or measurement systems used separately from the dilation and stent delivery catheters may be useful for assessing or confirming clinically relevant information related to stent delivery and stent placement, these separate systems may lead to extra procedure time, cost, and potential for complications, e.g., because these systems are separate (e.g., physically and communicatively) from the dilation and stent delivery catheters. For example, after a post-dilation expansion of the stent, a clinician may need to remove the post-dilation catheter from the patient in order to insert a separate catheter or medical device system configured for imaging and / or measurement. Examples of such separate and independent systems include intravascular ultrasound (IVUS) or optical coherence tomography (OCT) systems. Additionally, other non-invasive methods of confirming vessel opening (e.g., angiography) may not be accurate and / or precise enough to measure and / or confirm relevant measures of clinical effectiveness, including the degree of stent expansion or the degree of stent apposition.

[0045] In examples described herein, the catheters (e.g., balloon catheters) are configured for expansion against a vessel wall and / or against a stent to open up the vessel and / or expand the stent. In other words, the devices described herein may be configured to perform one or more of pre-dilation, stent delivery, stent expansion, and / or post-dilation stent expansion. In someDocket No.: A0012639W001 / 1241-321W001 examples, the balloon catheters are also configured to enable determination of one or more clinically relevant parameters, measurements, or indices related to stent expansion (e.g., pressures and / or forces applied to and / or by the balloon against a stent and / or a vessel wall, as well as information about a blood vessel, including lesion morphology). Using such a multifunctional system may reduce procedure time and risk for complications by reducing the number of catheters that need to be introduced (e.g., inserted) and removed from the patient. For example, the need for IVUS or OCT systems may be reduced or eliminated, as the catheter systems described in this disclosure may be configured to determine or confirm the parameters and / or measurements that IVUS or OCT systems would normally generate. Particularly in emergency cases where time is limited, using the multi-functional devices described herein may lead to improved patient outcomes, e.g., by sufficiently restoring blood flow to a sufficient level in less time as compared to when separate systems are used. It should be understood that it may still be possible to use IVUS or OCT in addition to the techniques described in this disclosure. For example, in some examples, the medical devices systems described herein are configured to co-register with one or more separate imaging modalities. Such separate imaging modalities can include IVUS, OCT, angiography, computed tomography (CT), and / or magnetic resonance imaging (MRI).

[0046] Additionally, the systems may be configured to be a “smart” feedback system, such that balloon and / or stent expansion is automatically driven based on measurements (e.g., force values, pressure values, morphologies, etc.) of the system. Such “smart” systems may reduce or eliminate the need for clinician input, which may reduce time and the potential for human error while increasing safety for patients. For example, the systems described herein may provide (e.g., generate) recommendations to a clinician related to one or more medical procedures, such as angioplasty, stenting, assessment of lesion morphology, or related medical procedures.

[0047] During manufacturing of stent delivery systems, a stent is crimped onto a balloon such that the stent is transformed to a radially compressed configuration around a portion of the balloon. The crimping force used to crimp the stent onto the balloon can create frictional engagement between the stent and the balloon such that the stent resists movement relative to balloon, e.g., as the stent is being navigated through vasculature of a patient to a target location. In some cases, a higher crimping force can correspond to a greater frictional engagement between the stent and the balloon. Greater frictional engagement can enable the balloon to more easily retain the stent such that the probability of stent movement relative to the balloon (e.g., movement axially and or circumferentially relative to the balloon) is reduced or even eliminated. However, in some cases, the crimping force is selected to minimize alteration of the balloon material (e.g., alteration that can create holes and / or other structural alterations that couldDocket No.: A0012639W001 / 1241-321W001 otherwise impact the performance of the balloon, such as the ability to inflate). In some cases, minimizing alteration of the balloon material can be achieved via a relatively lower crimping force. Thus, crimping of a stent onto a balloon requires a suitable process using a crimping force that creates a suitable frictional engagement between the balloon and the stent without significantly altering the balloon material.

[0048] The devices and techniques described herein can facilitate stent retention on medical balloons while simultaneously reducing impact (e.g., physical alteration) of portions of the balloon onto which a stent is crimped. For example, the balloons described herein can include at least one layer that is configured to be relatively softer than other radially adjacent layers such that a stent at least partially embeds into the relatively softer layer during the crimping process. However, the devices described herein can be configured such that the crimping process structurally alters some layers (e.g., the radially outermost layer) without impacting other radially adjacent layers.

[0049] Additionally and / or alternatively, the devices and techniques described herein can enable one or more sensors to be carried by the balloon without significantly increasing the greatest cross-sectional dimension (e.g., diameter) of the balloon. For example, one or more layers of the balloon (e.g., the relatively less hard outermost layer) can include structural features (e.g., pockets) configured to received and / or retain one or more sensors. Such sensors can be configured to facilitate determination of clinically relevant features related to PCI procedures (e.g., parameters related to lesions, stent expansion and / or apposition, and / or the like).

[0050] In the examples described herein, a medical device system includes a medical device such as a catheter system (e.g., a balloon catheter system). The catheter system includes an elongated body and an expandable structure (e.g., a balloon) at a distal portion of the elongated body. In some examples herein, the balloon includes at least one layer (e.g., a layer of material), such as a radially outermost layer, that is relatively less hard (e.g., has a relatively lower Shore D hardness) than other radially adjacent (e.g., more radially inward) layers. In some examples, a radially outmost layer that is relatively less hard enables a stent and / or one or more sensors to be at least partially embedded and / or otherwise retained by the third layer, such that the stent and / or the one or more sensors is retained on the balloon (e.g., such as during navigation of the expandable structure as well as the balloon and / or the one or more sensors through vasculature of a patient). In examples in which the balloon is used in a stent delivery and / or stent expansion procedure, the outer layer of the balloon can be configured to help retain the stent on the balloon (e.g., because at least some portions of the stent are at least partially embedded in the outer layer of material and frictionally engaged, which may reduce a likelihood of the stent moving axially or rotationally relative to the balloon). In some examples in which one or more sensors areDocket No.: A0012639W001 / 1241-321W001 carried by the balloon, at least the radially outmost layer can include structural features (e.g., one or more pockets) configured to receive the one or more sensors, such that the balloon can carry one or more sensors without substantially increasing the widest cross-sectional dimension of the balloon.

[0051] In the examples described herein, the balloon includes multiple layers of material (e.g., multiple radially adjacent layers comprising different materials having different material properties). In some examples herein, a balloon includes at least a first layer having a first Shore D hardness, a second layer having a second Shore D hardness and positioned radially outward of the first layer, and a third layer having a third Shore D hardness and positioned radially outward of the first layer and the second layer. In some examples, the third Shore D hardness of the third layer (e.g., the radially outermost layer) is equal to or less than the first Shore D hardness of the first layer and less than the second Shore D hardness of the second layer. In some examples, the second Shore D hardness of the second layer (e.g., the radially middle layer that is radially outside of the first layer and radially inside of the third layer) is greater than the first Shore D hardness of the first layer and the third Shore D hardness of the third layer. The relatively greater Shore D hardness of the second layer can enable the balloons described herein to have suitable mechanical properties (fatigue resistance and / or burst pressure), which can enable the balloon to apply a suitable expansion force on a stent and / or a vessel wall (e.g., including a radial force against plaque). In some examples, the first layer having the first Shore D hardness contributes to the suitable mechanical properties (fatigue resistance and / or burst pressure) of the balloon (e.g., to enable the balloon to apply a suitable expansion force on a stent and / or a vessel wall).

[0052] The relatively lower third Shore D hardness of the third layer (e.g., which may be a radially outermost layer) can facilitate relatively better retention of the stent on the balloon (e.g., as compared to other balloons including an outermost layer with a relatively higher Shore D hardness). For example, because the balloons described herein include multiple layers with a radially outermost layer having a relatively lower Shore D hardness, a relatively greater crimping force may be used to crimp a stent onto the balloon which may cause the stent to embed into the radially outmost layer and facilitate relatively greater stent retention. Because other layers (e.g., other, more radially inward layers) of the balloon are minimally impacted during the crimping process (e.g., as least compare to the outermost layer), such layers can enable the balloon to maintain a suitable burst pressure and / or suitable fatigue resistance during use. Because the radially outermost layer of the balloon may become mechanically compromised (e.g., by design) during the crimping process in which the stent is at least partially embedded in the radially outermost layer, the radially outermost layer can be considered a “sacrificial” layer.Docket No.: A0012639W001 / 1241-321W001

[0053] While the balloons described herein include a relatively less hard radially outer layer of material, other layers (e.g., other radially adjacent layers, such as layers radially inward of the radially outermost layer) can be configured to enable the expandable structure (e.g., balloon) to maintain a suitable burst pressure, fatigue resistance, and / or other relevant properties. For example, the inner layers can include a relatively higher Shore D hardness as compared to the outermost layer, which can enable the balloon to have a suitable burst pressure, fatigue resistance, and / or have suitable expansion properties (e.g., expansion properties under pressure, such as minimal diameter growth above a given rated pressure). Because the radially inward layers (e.g., radially inward as compared to a radially outermost layer) may contribute less to retaining a stent on the ballon (e.g., at least compared to a radially outermost layer), the use of relatively higher durometer materials for such radially inward layers is enabled.

[0054] Although the balloons described herein include multiple radial layers (e.g., at least two layers, such as three or more layers), the expandable structures can define a comparable and / or a relatively lower wall thickness as compared to other expandable structures (e.g., balloons) used for similar medical procedures, such as stent delivery and / or stent expansion. In some examples, the expandable structures described herein define a wall thickness (e.g., double wall thickness measuring all radially adjacent layers) that is equal to or less than typical balloons used in similar procedures (e.g., such as stent delivery). Such relatively lower double wall thickness (DWT) values of the expandable structures described herein can enable the expandable structures to navigate through torturous anatomy and / or cross narrow portions within vasculature of a patient (e.g., while simultaneously facilitating stent retention and / or the ability to have one or more sensors at least partially embedded in the balloon).

[0055] In some examples, one or more portions of the medical device (e.g., such as the expandable structure) are configured to expand against a wall of a vessel and / or stent, e.g., to expand the stent against the vessel wall. For example, the catheter systems described herein can be configured for use in a pre-dilation expansion procedure (also referred to herein as a predilatation procedure), in a stent delivery and / or stent expansion procedure, and / or a post-dilation expansion procedure (also referred to herein as a post-dilatation procedure). Additionally or alternatively, in some examples, the expandable structures described herein can be configured for use in a plain old balloon angioplasty (POBA) procedure (e.g., to compress and / or soften plaque).

[0056] In some examples herein, in which one or more portions of the medical device (e.g., such as the expandable structure) include one or more sensors, the medical device system can be used to measure, determine, and / or output one or more relevant medical parameters. For example, the one or more sensors can enable the medical device system to measure and / or determine parameters associated with stent delivery and / expansion (e.g., such as a level of stentDocket No.: A0012639W001 / 1241-321W001 apposition against a vessel wall and / or a level of stent expansion). In some examples, the one or more sensors can enable the medical device system to measure and / or determine parameters associated with lesion and / or plaque morphology (e.g., such as determining a lesion classification, which can include calcific, fatty, fibrous, or the like).

[0057] In examples where the medical device includes one or more sensors carried by the expandable structure, the sensor may be physically and communicatively coupled to processing circuitry of the medical device system. The processing circuitry can be configured to receive and process signals to determine one or more measures, indices, parameters related to the balloon, the blood vessel, or the stent, e.g., while the distal portion of the catheter system is introduced (e.g., inserted) into the blood vessel of the patient. The measures, indices, parameters related to the balloon, the blood vessel, or the stent can include force values and / or pressure values based on forces and / or pressure applied by a stent or a blood vessel wall against the expandable structure (e.g., as measured by the one or more sensors carried by the expandable structure), as well as physiological information of the patient, including lesion morphology. In some examples, the processing circuitry is configured to determine deformation and / or expansion of various portions of the balloon (e.g., by measuring strain via strain sensors). In this way, a clinician may be enabled to receive indications of measures, indices, parameters related to the balloon, the blood vessel, or the stent and / or indications of the physiological information with the same device the clinician would use to expand the blood vessel and / or would use to deliver and / or expand the stent.

[0058] In some examples described herein, the processing circuitry is configured to determine and / or generate, for output to a user (e.g., a clinician), relevant information of and / or relating to parameters (e.g., force and / or pressure) measured and / or detected by the one or more sensors. In some examples, the processing circuitry is configured to determine a map of force values and / or pressure values (e.g., a map over a surface of the expandable structure and / or the stent). In some examples, the processing circuitry is configured to generate, for output (e.g., on a user interface), the map of force values and / or pressure values. In some examples, the processing circuitry is configured to determine and / or generate for output, one or more locations of malapposition of the stent against the blood vessel wall. In some examples, the processing circuitry is configured to determine and / or generate for output, one or more degrees of apposition of the stent against the blood vessel wall (e.g., adequately apposed, semi-adequately apposed, inadequately apposed, and / or malapposed). In some examples, the processing circuitry is configured to determine and / or generate for output, a shape (e.g., a geometry, including a cross- sectional shape at one or more locations) of the balloon and / or the stent based on the one or more force values and / or pressure values.Docket No.: A0012639W001 / 1241-321W001

[0059] Such information can enable a user (e.g., a clinician) to make clinically relevant decisions. For example, such information determined via sensors can enable a clinician to target and / or selectively expand particular portions of the stent (e.g., a distal portion, a proximal portion, or the like) to improve the apposition of the stent against the blood vessel wall at such portions. In some examples, the processing circuitry is configured to determine and / or generate for output, a shape (e.g., a geometry, including a cross-sectional shape at one or more locations) of a blood vessel (e.g., including a geometry and / or shape of a lesion) based on the one or more force values and / or pressure values. Such information can enable a user (e.g., a clinician) determine whether clinical intervention is needed (e.g., whether to compress the lesion, which can include plaque, via an angioplasty or stenting procedure). Such information can enable a user (e.g., a clinician) to select an appropriate stent (e.g., e.g., a sizing, including length and diameter of one or more stent), and / or make another clinically relevant decision.

[0060] As described herein, lesion morphology can include classifications of lesions and / or plaque such as calcific, fatty, fibrous, or the like. Other morphological information of lesions may include one or more of plaque composition, concentricity or eccentricity, tortuosity, regularity or irregularity of contour, absence or presence of thrombus, ostial or non-ostial, etc.

[0061] Although the example techniques described herein are described in many instances with reference to blood vessels (for example, cardiac blood vessels) and stents, the example techniques also have application to other anatomical sites (e.g., other suitable hollow and / or tubular anatomical structures, including brain ventricles, gastrointestinal tract such as the esophagus and / or intestines, the urinary track and associated structures, etc.) and the devices and systems described herein can be configured (e.g., have suitable shape and dimensions) for such sites. For example, the catheter systems described in this disclosure may be configured to access and determine information about other blood vessels, such as the neurovasculature, peripheral vasculature, or other suitable vascular sites. In some examples, the catheter systems described in this disclosure can be used to access coronary structures (e.g., such as for structural heart applications).

[0062] As used herein, the terms “distal” and proximal” define a position or direction with respect to the treating clinician or clinician’s control device (e.g., a handle assembly). “Distal” or “distally” can refer to a position distant from or in a direction away from the clinician or clinician’s control device. “Proximal” and “proximally” can refer to a position near or in a direction toward the clinician or clinician's control device.

[0063] While this disclosure is primarily described in term of diameters of vessels, stents, expandable structures, and / or other bodies which are generally tubular structures having generally circular cross-sections, other related and / or derivative measures (including radii, area,Docket No.: A0012639W001 / 1241-321W001 volume, surface area, maximum dimension, minimum dimension, etc.) may be understood to be interchangeable where a diameter is determined, evaluated, or otherwise referenced.

[0064] FIG. 1 A, FIG. IB, and FIG. 1C illustrate a medical device system 100 and various components thereof. FIG. 1 A is a partially schematic perspective view illustrating a medical device system 100 configured in accordance with examples of the present disclosure. As illustrated in the example of FIG. 1A, medical device system 100 includes a catheter system 108. Catheter system 108 includes an elongated body 110 configured to be introduced (e.g., inserted) into a blood vessel 102 of a patient 106 (e.g., by a clinician) and positioned within blood vessel 102. Catheter system 108 includes one or more expandable structures (e.g., at a distal portion of catheter system 108), such as a balloon 112. FIG. IB illustrates a detail view of a distal portion of catheter system 108 including balloon 112 of FIG. 1 A. FIG. 1C illustrates a cross-sectional view of balloon 112, the cross section taken through the A-A section lines in the example of FIG. IB. While the term “catheter system” is used to throughout this disclosure with reference to catheter system 108, in other examples, catheter system 108 can additionally or alternatively be referred to as catheter 108.

[0065] Balloon 112 can have any suitable configuration. In some examples, as illustrated in the example of FIG. IB, balloon 112 includes a body portion 114 extending between a body proximal end 114A and body distal end 114B. In an expanded configuration, balloon 112 can define a maximum outer dimension DI (which may also be referred to herein a diameter DI in examples where balloon 112 includes a circular cross-section). Balloon 112 can be configured to transform to a delivery (e.g., compressed) configuration in which balloon 112 defines a smaller maximum outer dimension as compared to maximum outer dimension DI.

[0066] In the example of FIG. IB, balloon 112 includes a proximal waist portion 116A and a distal waist portion 116B. In some examples, one or more of proximal waist portion 116A and distal waist portion 116B define a smaller maximum outer dimension than body portion 114 (e.g., when balloon 112 is in the expanded configuration). In some examples, proximal waist portion 116A is mechanically coupled (e.g., fixedly mechanically coupled) to a portion of elongated body 110 (e.g., distal portion 110A of elongated body 110).

[0067] In the example of FIG. IB, balloon 112 includes a proximal cone portion 115A and a distal cone portion 115B. In the expanded configuration of balloon 112, proximal cone portion 115A tapers between body portion 114 (e.g., between body proximal end 114A of body portion 114) and proximal waist portion 116A. In the expanded configuration of balloon 112, distal cone portion 115B tapers between body portion 114 (e.g., body distal end 114B of balloon body portion 114) and distal waist portion 116B.Docket No.: A0012639W001 / 1241-321W001

[0068] In some examples, balloon 112 is configured to expand (e.g., by inflation) when elongated body 110 is positioned within blood vessel 102 of patient 106. Balloon 112 may be configured to expand, for example, to be inflated and expand a stent 160 (e.g., as shown in FIG. IB) against a vessel wall 104 of the blood vessel 102 (e.g., either as a stent-delivery balloon or a post-dilation balloon). In some examples, balloon 112 (e.g., at least body portion 114) is configured to expand and exert a sufficient force on stent 160 to cause stent 160 to expand into apposition with vessel wall 104. In some examples, balloon 112 (e.g., at least body portion 114) is configured to expand within blood vessel 102 against vessel wall 104, such as during a predilation procedure to open blood vessel 102 or compress plaque before placement and / or before expansion of stent 160. Elongated body 110 defines a central longitudinal axis 111 extending through a distal end 158 of elongated body 110. Balloon 112 can additionally and / or alternative define central longitudinal axis 111. Balloon 112 may be configured to expand radially outwards relative to central longitudinal axis 111 (e.g., substantially perpendicular to central longitudinal axis 111) when balloon 112 is inflated within blood vessel 102 of patient 106.

[0069] In some examples, balloon 112 is configured to expand to a range of dimensions (e.g., diameters). For example, balloon 112 can be a compliant balloon and configured to expand to define a particular dimension within the range based on an inflation pressure within the balloon. In examples, the expanded dimension of balloon 112 is selected by a clinician based on a size of blood vessel 102, e.g., selected to enable balloon 112 to contact vessel wall 104 of blood vessel 102. In examples where balloon 112 is a compliant balloon, balloon 112 may be configured to exhibit a radial growth of about 10 percent or greater over a working range of pressures.

[0070] In some examples, balloon 112 is configured to expand to a fixed or relatively fixed dimension (within a tolerance) over a range of pressures. For example, balloon 112 can be a non- compliant balloon and configured exhibit less expansion over a working range of pressures such as to define a particular dimension regardless of what inflation pressure is selected by a clinician. As long as a minimum pressure is supplied to balloon 112, balloon 112 may be configured to expand to define the particular dimension, and remain at the particular dimension with slight or no expansion as pressure is further increased in balloon 112. In examples where balloon 112 is a non-compliant balloon, balloon 112 may be configured to exhibit a radial growth of about 4 to 6 percent over a working range of pressures.

[0071] In some examples, balloon 112 is configured to exhibit growth rates between that of a compliant balloon and a non-compliant balloon. For example, balloon 112 can be a semi- compliant balloon and configured to exhibit a growth of about 8 to 10 percent over a working range of pressures.Docket No.: A0012639W001 / 1241-321W001

[0072] In examples, balloon 112 is configured such that an imaging system (e.g., an imaging system extracorporeal to patient 106) can capture an image of balloon 112 when balloon 112 is within patient 106. In some examples, elongated body 110 and / or balloon 112 includes one or more radiopaque markers for visualization via a suitable medical imaging technique.

[0073] In some examples, as illustrated in the example of FIG. IB and FIG. 1C, catheter system 108 additionally includes stent 160, which may be delivered and / or expanded via catheter system 108. In some examples, stent 160 defines a body portion extending between a stent body proximal end 161 A and a stent body distal end 161B. Stent 160 can include a plurality of interconnected struts 162. While the example of FIG. IB only illustrates cross-sectional views of particular struts 162, stent 160 can include interconnected struts 162 that generally form a tubular body of stent 160. In some examples, stent 160 defines a lumen such that stent can be positioned over balloon 112.

[0074] In the example of FIG. IB, stent 160 is at least partially expanded against a portion of blood vessel 102 that includes a lesion 105. Stent 160 is partially expanded because a portion of stent 160 abutting lesion 105 is narrowed compared to the largest diameter (e.g., diameter VI) of blood vessel 102. Lesion 105 may include any abnormal narrowing of blood vessel 102, including material in or within blood vessel 102 that be fibrous, calcific, fatty, thrombogenic, or a combination thereof.

[0075] In the example of FIG. IB, balloon 112 is in an at-least partially expanded (e.g., inflated) configuration press against stent 160 with enough pressure to conform to the at least partially expanded diameter of stent 160.

[0076] In some examples, balloon 112 is configured to transform to a low-profile (e.g., delivery) configuration. In some examples, in the delivery configuration, balloon 112 defines a diameter small enough to be delivery across stent 160 (e.g., narrow enough to fit through an opening defined by the at least partially expanded stent 160).

[0077] In some examples, as illustrated in each of FIG. 1 A, FIG. IB, and FIG. 1C, catheter system 108 includes one or more sensors 142. In some examples, the one or more sensors 142 include a pressure sensor, a force sensor, and / or a strain sensor. For example, sensors 142 can include one or more piezoresistive sensors (e.g., that include one or more piezoresistive materials), and / or another type of resistive sensor configured to measure force and / or pressure (e.g., force and / or pressure applied to an external surface of balloon 112) and / or strain (e.g., strain due to expansion or contraction of balloon 112). In some examples, sensors 142 are configured to generate an electrical signal, which can change based on an amount of force and / or pressure applied to sensors 142. In some examples, a voltage level of the electrical signal that is output by sensors 142 changes based on the level (e.g., amount) of applied force and / or pressureDocket No.: A0012639W001 / 1241-321W001 to sensors 142. In some examples, as discussed more fully herein, sensors 142 are carried by (e.g., disposed on, embedded in, mechanically coupled to, or the like) balloon 112. For example, as discussed in connection with FIG. 1C and FIG. 3B, one or more of sensors 142 can be at least partially embedded in at least an outermost layer of balloon 112. Sensors 142 can additionally or alternatively include other types of sensors including strain sensors (e.g., sensors that are configured to put out a variable electrical signal based on an amount of deformation), temperatures sensors, pressure sensors configured to determine a level of pressure inside of balloon 112, and / or other suitable types of sensors.

[0078] In examples where multiple sensors 142 are carried by balloon 112, each of the multiple sensors may be configured to provide relevant information associated with a specific location relative to a surface of balloon 112. For example, in some examples, balloon 112 includes sensors 142 positioned at one or more of a proximal portion, distal portion, and / or a portion between the proximal and distal portion. In some examples, balloon 112 includes sensors 142 at multiple circumferential positions around a circumference of balloon 112.

[0079] In some examples, as illustrated in FIG. IB, balloon 112 is delivered intravascularly to the treatment location (e.g., proximate a lesion 105) using a guidewire in an over the wire (OTW) technique or a rapid exchange (RX) technique. At the treatment location, the guidewire can be left inserted, and balloon 112 may be expanded from the delivery configuration to a partially expanded configuration (e.g., as shown in FIG. 3 A) and / or to a fully expanded configuration. In some examples, the guidewire is removed or partially removed prior to inflating and / or expanding balloon 112. In some examples, balloon 112 may position sensors 142 proximate to stent 160, e.g., such that sensors 142 can measures a reaction force and / or pressure of stent 160 as stent is expanded within blood vessel 102.

[0080] In some examples, as illustrated in FIG. 1 A, medical device system 100 includes a device 130 configured to control, monitor, supply, and / or otherwise support operation of medical device system 100 (e.g., including catheter system 108). In some examples, device 130 includes one or more of a processing device, power generation device, which may include any suitable configuration of inputs, outputs, displays, power supplies, and / or combinations of hardware and software for functioning of medical device system 100. While device 130 is described in connection with catheter system 108, device 130 may be configured in other ways, such for use with multiple catheters and / or other medical systems, including other medical imaging systems such as IVUS and OCT systems.

[0081] In some examples, device 130 may include (or be coupled to) a user interface 132 configured to receive input from a user and / or output information to a user. For example, user interface 132 can include a button or keypad, a touch screen, a speaker configured to receiveDocket No.: A0012639W001 / 1241-321W001 and / or output audible information, and / or a display, such as a liquid crystal (LCD), light-emitting diode (LED), or organic light-emitting diode (OLED). In some examples, user interface 132 is configured to output (e.g., present or display) information, such as one or more an indication of one or more force values and / or pressure values sensed by sensors 142 of balloon 112. In some examples, user interface 132 is configured to output a graphical representation (e.g., an image, picture, schematic representation, etc.) of blood vessel 102, other anatomical structures (e.g., a lesion, plaque, a blood vessel wall, and / or the like), stent 160, and / or balloon 112. In some examples, user interface 132 is configured to output the graphical representation of blood vessel 102, other anatomical structures (e.g., a lesion, plaque, a blood vessel wall, and / or the like), stent 160, and / or balloon 112 including one or more determined values (e.g., one or more force values and / or pressure values, including a map of force values and / or a map of pressure values). The graphical representation can include one or more colors, legends, and / or other keys.

[0082] In some examples, device 130 is configured to control, monitor, supply, and / or otherwise support operation of catheter system 108. For example, device 130 can be configured to generate a selected form and / or magnitude of energy (e.g., current) to sensors 142. In some examples, device 130 can include a generator configured to generate energy used for either diagnostic or therapeutic purposes (e.g., pulsed field, electrical current, microwave, radiofrequency, monopolar, and / or bipolar energy). In other examples, device 130 may be another type of device configured to generate and deliver another suitable type of energy to catheter system 108. In some examples, device 130 is configured to receive one or more resulting signals from sensors 142 based on the signals applied to sensors 142. For example, device 130 can be configured to receive a resulting voltage signal from sensors 142, e.g., for determination of one or more of a pressure and force applied to sensors 142 and / or balloon 112.

[0083] In the example of FIG. IB, balloon 112 is shown in at least partially expanded (e.g., inflated) configuration to exert pressure against stent 160 with enough pressure to conform to the at least partially expanded diameter of stent 160, but not enough pressure to further expand stent 160. At this point, a user (e.g., a clinician) may initiate, or device 130 may automatically initiate, determination of one or more forces and / or pressures applied to sensors 142 and / or balloon 112. Such determination of one or more forces and / or pressures applied to sensors 142 can enable device 130 to determine (e.g., generate) a map (e.g., a spatial representation) of pressure values and / or force values applied by stent 160 against the portion of balloon 112 that includes sensors 142. In some examples, device 130 determines (e.g., and / or generates, for output via user interface 132), based on the one or more forces and / or pressures applied to sensors 142, an indication of stent malapposition of stent 160 against vessel wall 104, a degree of stent apposition of stent 160 against vessel wall 104, an indication of a stent crimp zone of stent 160 (e.g., byDocket No.: A0012639W001 / 1241-321W001 determining areas of uniform low pressure along an axial length of balloon 112), and / or other relevant indices and / or parameters related to stent 160 and / or blood vessel 102.

[0084] In examples where balloon 112 is at least partially expanded directly against vessel wall 104 of blood vessel 102 (e.g., without stent 160 between balloon 112 and vessel wall 104, which can include a portion of vessel wall including lesion 105), device 130 can be configured to determine (e.g., generate) a map of pressure values and / or force values applied by vessel wall 104 against the portion of balloon 112 that includes sensors 142. In some examples, device 130 is configured to generate a map of force values and / or map of pressure values based on the one or more forces and / or pressures applied to (e.g., directly applied to) sensors 142 and / or balloon 112 by vessel wall 104. This feedback can enable a clinician to determine whether to further expand balloon 112 (e.g., to further compress lesion 105, which can include plaque). In some examples, balloon 112 can be used as a plain old balloon angioplasty (POBA) catheter.

[0085] In some examples in which balloon 112 is expanded directly against a portion of vessel wall 104 that includes lesion 105, device 130 can be configured to determine a shape and / or geometry of lesion 105 based on one or more forces and / or pressures applied to (e.g., directly applied to) sensors 142 and / or balloon 112 by vessel wall 104. For example, in some examples, processing circuitry 30 is configured to determine a cross-sectional shape of lesion 105 based on force and / or pressure values corresponding to particular locations around balloon 112. Such information can enable a user (e.g., a clinician) determine whether clinical intervention is needed (e.g., whether to compress the lesion 105, which can include plaque via an angioplasty or stenting procedure). Such information can enable a user (e.g., a clinician) to select an appropriate stent (e.g., e.g., a sizing, including length and diameter of one or more stent), and / or make another clinically relevant decision.

[0086] In some examples, sensors 142 are carried balloon 112. For example, sensors 142 can be mechanically coupled to a surface (e.g., an external surface) of balloon 112 and / or be integrated into a wall of balloon 112. In some examples, as described further in connection with FIG. 1C and FIG. 3B, sensors 142 can be mechanically coupled to (e.g., and disposed in) one or more layers of balloon 112.

[0087] Sensors 142 may have any suitable configuration along and / or around balloon 112. In examples, one or more of sensors 142 wraps circumferentially around balloon 112, e.g., such that each of sensors 142 at least partially wraps around balloon 112. In some examples, one or more sensors of sensors 142 completely circumnavigates balloon 112. In examples, as illustrated in FIG. IB, each sensor of sensors 142 extends along balloon 112, e.g., such that each of sensors 142 extends at least a partial distance along balloon 112 between proximal cone portion 115A and distal cone portion 115B of balloon 112. In some examples, one or more of sensors 142Docket No.: A0012639W001 / 1241-321W001 extends completely between proximal cone portion 115A and distal cone portion 115B of balloon 112 (e.g., such that one or more of sensors 142 extend between body proximal end 114A and body distal end 114B of balloon body portion 114).

[0088] Although the example of FIG. IB illustrates catheter system 108 with two sensors 142, catheter system 108 can include any suitable number of sensors 142 (e.g., one, two, three, four, five, six, seven, eight, nine, ten, twelve, fifteen, twenty, fifty, one-hundred, or more sensors 142, etc.). The number and / or spacing of sensors 142 may correspond to the granularity of measurements via sensors 142. For example, including sensors 142 spaced closer together (e.g., closer together along central longitudinal axis 111) may facilitate a more granular determination of diameters of balloon 112 along central longitudinal axis 111. Further, a number of sensors can depend on a size (e.g., length and / or diameter) of balloon 112. For example, a longer balloon can be configured to include more sensors along the length of the balloon as compared to a balloon with shorter length, e.g., to maintain a similar granularity of measurement between each of the two balloons.

[0089] Elongated body 110 can include any suitable configuration for supporting sensors 142 and / or balloon 112. In some examples, as shown the example of FIG. 1 A, elongated body 110 defines a distal portion 110A (also referred to herein as distal body portion 110A) and a proximal portion HOB (also referred to herein as proximal body portion HOB). Plurality of sensors 142 and / or balloon 112 are positioned on and / or carried by distal portion 110A in the example shown in FIG. 1 A. In some examples, catheter system 108 is configured to assume a relatively low- profile delivery configuration in which at least one of distal portion 110A and / or balloon 112 defines a fist dimension (e.g., a diameter), which can be measured in a direction perpendicular to central longitudinal axis 111. The first dimension may define a dimension sufficient to allow the passage of at least distal body portion 110A and balloon 112 through vasculature of patient 106 to reach a target treatment location within patient 106. In some examples, elongated body 110 defines a lumen 113 for receiving the guidewire for delivery of elongated body 110 (e.g., at least distal body portion 110A) using a suitable technique, e.g., either an over the wire (OTW) technique or a rapid exchange (RX) technique.

[0090] In some examples, medical device system 100 includes a handle portion 150 coupled to proximal body portion 110B, which is configured to remain outside vasculature of patient 106 when distal body portion 110A is within vasculature of patient 106. Handle portion 150 may be configured to allow a clinician to navigate at least distal body portion 110A through the vasculature, allow inflation and / or deflation of balloon 112, and / or enable other functions of medical device system 100 which may assist in the delivery of a treatment to patient 106. At least some portion of catheter system 108 (e.g., distal body portion 110A) may be substantiallyDocket No.: A0012639W001 / 1241-321W001 flexible, such that catheter system 108 may flex and / or bend enroute to positioning balloon 112 and / or sensors 142 within blood vessel 102 of patient 106. Hence, although illustrated as substantially linear in FIG. 1 A, catheter system 108 (or portions thereof) may be configured to assume linear, curved, and / or curvilinear shapes. Correspondingly, central longitudinal axis 111 (and / or portions thereof) defined by catheter system 108 may be linear, curved, and / or curvilinear.

[0091] In some examples, balloon 112 may be delivered with a guide device, such as guide sheath (not shown in the examples of FIG. 1 A or FIG. IB), with or without a using guidewire. In examples in which catheter system 108 includes a guide sheath, when balloon 112 is at the target treatment location, the guide sheath may be at least partially withdrawn or retracted or balloon 112 is advanced beyond the distal end of the guide sheath so that balloon 112 may be transformed into an expanded configuration. In other examples, elongated body 110 may be steerable itself such that balloon 112 and / or sensors 142 may be delivered to the treatment location without the aid of a guidewire and / or a guide sheath.

[0092] In some examples, distal body portion 110A is configured to locate sensors 142 at an intraluminal (e.g., intravascular) location. Intraluminal (e.g., intravascular) locations can include blood vessels with diameters on the order of millimeters, such as about 1 mm to 8 mm. In some examples, target locations include one or more coronary arteries, such as the left main coronary artery (LMCA), left anterior descending artery (LAD), and / or circumflex artery (CX), and Right Coronary Artery (RCA), and their respective side branches. However, other blood vessels of smaller or larger sizes are contemplated (e.g., cranial blood vessels, peripheral blood vessels, etc.). Balloon 112 is configured to expand from the delivery configuration to an expanded configuration (e.g., FIG. IB) to, for example, position and / or stabilize distal body portion 110A and / sensors 142 when distal body portion 110A locates sensors 142 at the target treatment location.

[0093] In examples where balloon 112 is expanded against a stent (e.g., stent 160 as shown in the examples of FIG. IB and FIG. 1C), device 130 can be configured to determine one or more locations of adequate stent apposition, stent malapposition (e.g., against vessel wall 104 of blood vessel 102), one or more degrees of apposition of stent 160 against vessel wall 104, as well as other measures and indices related to the expansion of stent 160 and the apposition of stent 160 against vessel wall 104 of blood vessel 102.

[0094] Catheter system 108 can include one or location references markers (e.g., radiopaque structures, such as markerbands positioned on elongated body 110). In some examples, one or more of sensors 142 themselves can serve as location references markers. In some examples, such location reference markers can enable a clinician and / or device 130 to align a portion ofDocket No.: A0012639W001 / 1241-321W001 balloon 112 (e.g., balloon body portion 114) with stent 160. For example, because one or more portions of stent 160 can be visible via a suitable medical imaging modality (e.g., fluoroscopy, angiography, radiography, and / or the like), a clinician can align a portion of balloon 112 (e.g., balloon body portion 114), which may include sensors 142, with a portion of stent 160. Such alignment can enable a user and / or device 130 to determine which location of stent 160 is adequately apposed and / or malapposed against vessel wall 104 via use of sensors 142.

[0095] Device 130 (of FIG. 1A) can include suitable hardware and software configurations to enable device 130 to receive and / or process signals from sensors 142. In some examples, device 130 is configured to receive and / or process signals from sensors 142 for determination of pressure and / or force values, including determination of a map of force values and / or a map of pressure values (e.g., a one-dimensional and / or a multi-dimensional mapping of force values and / or mapping of pressure values). In some examples, sensors 142 forms a sensor matrix including an array or grid of individual sensors.

[0096] As discussed herein, in some examples, device 130 (e.g., as illustrated in FIG. 1 A) is configured to receive signals from sensors 142 such that device 130 can determine a level of force and / or pressure applied to sensors 142, and thus also the force and / or pressure applied to balloon 112. For example, sensors 142 can be configured to receive and relay signals indicative of one or more forces and / or pressures applied to sensors 142. In some examples, device 130 is configured to receive, from sensors 142, the signals (e.g., voltage signal) indicative of one or more forces and / or pressures and determine, based on the signals, a level of the force and / or pressure applied to sensors 142 (e.g., based on the level of the voltage signal). For example, device 130 can be configured to determine one or more force values and / or pressure values based on the signals indicative of force and / or pressure applied to sensors 142. Such force values and / or pressure values can be determined before, during, and / or after balloon 112 is expanded to press against stent 160 or blood vessel wall 104 of blood vessel 102. In this way, device 130 can be configured to determine one or more force values and / or pressure values based on forces and / or pressures applied by stent 160 and / or blood vessel wall 104 against balloon 112 and / or sensors 142.

[0097] In some examples, as shown in the example of FIG. IB, catheter system 108 includes a plurality of conductor wires 144. Each of conductor wires 144 can be physically coupled to one or more of sensors 142 and device 130. In some examples, one or more of conductor wires 144 extend at least between one or more of sensors 142 and proximal portion 110B of elongated body 110. In some examples, conductor wires 144 extend to handle portion 150. In some examples, another component (e.g., a connector) is used to electrically couple device 130 to conductor wires 144. As discussed further in relation to other examples, each of conductor wires 144 can beDocket No.: A0012639W001 / 1241-321W001 at least partially embedded in material of balloon 112 and / or elongated body 110. In some examples, each of conductor wires 144 are completely embedded in material of balloon 112 and / or elongated body 110 (e.g., such that material of balloon 112 and / or elongated body 110 completely surrounds at least a portion of conductor wires 144).

[0098] In some examples, each of conductor wires 144 can be communicatively coupled and / or electrically coupled to one or more of sensors 142 and device 130. For example, sensors 142 and device 130 can be electrically coupled such that electrical signals can be transmitted between sensors 142 and device 130. Sensors 142 and device 130 may additionally or alternatively be communicatively coupled in other ways, including via printed circuits, or other suitable techniques, including, but not limited to, intermediate microelectronics, microelectromechanical system (MEMS) devices, and the like. In other examples, sensors 142 and device 130 are configured to communicate wireless and / or at least partially wirelessly.

[0099] As illustrated in FIG. 1A, medical device system 100 includes a cable 147 configured to deliver power and / or facilitate communication between device 130 and catheter system 108. Along cable 147 or at another suitable location within medical device system 100, medical device system 100 may include a control device 145 configured to initiate, terminate, and / or adjust operation of one or more components of catheter system 108 directly and / or via device 130. In some examples, cable 147 is configured to electrically couple device 130 to sensors 142 and / or conductor wires 144. In some examples, device 130 is configured to execute an automated control algorithm and / or to receive control instructions from an operator. Similarly, in some implementations, device 130 is configured to provide feedback to an operator before, during, and / or after a treatment procedure via an evaluation / feedback algorithm.

[0100] In examples, catheter system 108 is configured to inflate and / or expand balloon 112 with a fluid (e.g., liquid) such as water, saline, contrast, conductive fluid, another suitable liquid, or a combination thereof. In some examples, balloon 112 defines an interior volume 117, e.g., such that balloon 112 is configured to be inflated by fluid (e.g., a liquid). In some examples, the fluid is water or saline. In some examples, catheter system 108 is configured such that the fluid may flow into a fluid inlet 148, through an inlet lumen defined by elongated body 110, through interior volume 117, in order to inflate balloon 112. Fluid inlet 148 may also serve as an outlet, e.g., such as to remove fluid and deflate balloon 112. In some examples, device 130 is configured to inflate balloon 112, e.g., through controlled delivery of a fluid. However, in other examples, a separate automated device (e.g., pump) or manual device (e.g., hand-held syringe or other manual balloon catheter inflation device) inflates balloon 112.

[0101] FIG. 1C illustrates a cross-sectional view of balloon 112 of catheter system 108, the cross section taken through the A-A section lines in the example of FIG. IB. As shown in theDocket No.: A0012639W001 / 1241-321W001 example of FIG. 1C, balloon 112 includes a first layer 118A, a second layer 118B positioned radially outward of first layer 118A, and a third layer 118C positioned radially outward of first layer 118A and second layer 118B. In some examples, first layer 118A is a radially most inward layer of balloon 112. In some examples, third layer 118C is a radially most outward layer of balloon 112. In some examples, second layer 118B is directly adjacent to (e.g., directly radially adjacent to) first layer 118A. In some examples, third layer 118C is directly adjacent to (e.g., directly radially adjacent to) second layer 118B. In other examples, balloon 112 includes one or more other intermediate layers between first layer 118A and second layer 118B and / or between second layer 118B and third layer 118C.

[0102] In some examples, one or more of sensors 142 can be disposed in (e.g., embedded in), mechanically affixed to, and / or otherwise defined by at least third layer 118C, which may be an outermost layer of balloon 112. For example, in some examples, third layer 118C is configured to receive one or more sensors of sensors 142 such that sensors 142 are at least partially embedded in third layer 118C. In some examples, as discussed further with respect to FIG. 3 A and FIG. 3B, third layer 118C defines a pocket (e.g., otherwise referred to herein a recess, which may generally be an area of displaced or removed material) configured to receive one or more sensors 142.

[0103] In some examples, balloon 112 is configured to receive stent 160 such that stent 160 is at least partially embedded in one or more layers of balloon 112. For example, in some examples, at least third layer 118C is configured to receive at least a portion of stent 160 (e.g., one or more struts 162 of stent 160) such that stent 160 is at least partially embedded in (e.g., radially inward of a general plane of) third layer 118C (e.g., once stent 160 is crimped onto balloon 112 and while stent 160 is being navigated by balloon 112 through vasculature of patient 106).

[0104] Each of first layer 118A, second layer 118B, and third layer 118C of balloon 112 can define a suitable hardness. In some examples, first layer 118A defines first Shore D hardness, second layer 118B defines second Shore D hardness, and third layer 118C a third Shore D hardness. The relative values of each of first Shore D hardness of first layer 118A, second Shore D hardness of second layer 118B, and third Shore hardness of third layer 118C can be selected such that balloon 112 can more easily retain a stent (e.g., stent 160) and / or a sensor (e.g., sensor 142) while also maintaining suitable mechanical properties (e.g., suitable burst pressure and / or fatigue resistance) and / or suitable performance properties (e.g., deliverability, navigability, growth rate under pressure, and / or the like).

[0105] In some examples, the third Shore D hardness of third layer 118C is less than the second Shore D hardness corresponding to second layer 118B, which may be a layer directlyDocket No.: A0012639W001 / 1241-321W001 adjacent to and radially inward of third layer 118C. The third Shore D hardness of third layer 118C may be low enough such that stent 160 becomes at least partially embedded in third layer 118C by virtue of being crimped onto balloon 112. In some examples, third Shore D hardness corresponding to third layer 118C is 40D to 70D, such as 40D to 60D, 60D to 70D, or any suitable hardness or ranges of hardness therebetween. In some examples, third Shore D hardness corresponding to third layer 118C is less than 70D. In some examples, third Shore D hardness corresponding to third layer 118C is less than 60D. The third Shore D hardness of third layer may be low enough such that stent 160 displaces material of third layer 118C during the crimping process (e.g., while stent 160 is positioned onto body portion 114 of balloon 112 and crimped down onto balloon 112).

[0106] In some examples, the second Shore D hardness of second layer 118B is greater than the first Shore D hardness of (e.g., corresponding to) first layer 118A and greater than the third Shore D hardness of third layer 118C. In some examples, the second Shore D hardness corresponding to second layer 118B may be relatively high enough such that stent 160 does not become embedded in second layer 118B when stent 160 is crimped onto balloon 112. In some examples, the second Shore D hardness corresponding to second layer 118B (e.g., which may be a radially intermediate layer of balloon 112), is greater than or equal to 70D. In some examples, the second Shore D hardness corresponding to second layer 118B is greater than or equal to 74D. In some examples, the second Shore D hardness corresponding to second layer 118B is greater than or equal to 76D. In some examples, the second Shore D hardness corresponding to second layer 118B is greater than or equal to 80D. In some examples, because second layer 118B is not disrupted during a crimping process in which stent 160 is crimped onto balloon 112, second layer 118B can enable balloon 112 to maintain a suitable mechanical robustness (e.g., as measured by burst pressure) when inflated. Because third layer 118C may become altered during the crimping process in which stent 160 is at least partially embedded in third layer 118C, third layer 118C can be considered a “sacrificial” layer. Although third layer 118C can have one or more areas of a thin material from the crimping process, the overall mechanical integrity of balloon 112 remains intact because of the relatively higher Shore D hardness of at least second layer 118B, which is minimally or not affected during the crimping process.

[0107] In some examples, the third Shore D hardness of third layer 118C is less than or equal to the first Shore D hardness of first layer 118A. In general, the first Shore D hardness of first layer 118A can be similar to the third Shore D hardness of third layer 118C, but still less than the second Shore D hardness corresponding to second layer 118B. In some examples, first Shore D hardness corresponding to first layer 118A is 50D to 70D, such as 60D to 70D. The relatively lower first Shore D hardness of first layer 118A as compared to second layer 118B can enableDocket No.: A0012639W001 / 1241-321W001 balloon 112 to be relatively flexible while the overall balloon 112 structure has a relatively high burst pressure (e.g., due to the relatively higher Shore D hardness of second layer 118B).

[0108] Each of first layer 118A, second layer 118B, and third layer 118C can each have a suitable thickness (e.g., a thickness measured in a radial direction relative to central longitudinal axis 111). In some examples, second layer 118B is thicker as compared to first layer 118A (e.g., second layer 118B defines a greater wall thickness than first layer 118A). Such relative thickness can enable balloon 112 to maintain a relatively high burst pressure while having a relatively lower double wall thickness (e.g., as compared to balloons in which at least two radially inward layers have the same thickness).

[0109] In some examples, a thickness of third layer is based on a shape, size, and / or type of sensor 142 and / or stent 160. In some examples, third layer 118C defines a thickness of 0.000005 inches to 0.0001 inches. In some examples, the thickness of third layer 118C is selected based on the shape, size, and / or type of sensor 142. For example, a thickness of third layer 118C is equal to or greater than a thickness (e.g., of high) of one or sensors 142 (e.g., as measured in a radial direction relative to central longitudinal axis 111).

[0110] Balloon 112 can be formed from any suitable process and / or combination of processes. In some examples, balloon 112 is formed from an extruded tube (e.g., a co-extruded tube that includes at least three layers of material corresponding to each of first layer 118A, second layer 118B, and third layer 118C). In some examples, balloon 112 is fabricated via a suitable dip molding or blow molding process. For example, the extruded tube having the multiple (e.g., three) layers is inserted into a mold and pressurized such that material deforms and / or flows to conform to a mold having an internal shape corresponding to the shape of balloon 112 shown in at least FIG. IB. In some examples, the extruded tube and / or the molded balloon 112 undergoes a process in which material from one or more of proximal waist portion 116A, distal waist portion 116B, proximal cone portion 115A, and / or distal cone portion 115B is removed (e.g., via ablation and / or grinding), such as to reduce a wall thickness in such portions. Such removal of material can increase the flexibility and / or decrease the profile of one or more of proximal waist portion 116A, distal waist portion 116B, proximal cone portion 115A, and / or distal cone portion 115B, which can enable balloon 112 to more easily be delivered to a target location within blood vessel 102 of patient 106.[oni] In some examples, a first portion of layers of balloon 112 (e.g., less than all layers, such as first layer 118A and second layer 118B) are formed from a first process (e.g., molding process, as described above), and a second portion of layers of balloon 112 (e.g., third layer 118C) are formed from a second process (e.g., dip coating) different from the first process. For example, in some examples, a tube (e.g., a dual layer tube including first layer 118A and secondDocket No.: A0012639W001 / 1241-321W001 layer 118B) is molded to form an intermediate balloon, and the balloon undergoes a dip coating process such that the dip coating process adds third layer 118C to the molded balloon to form balloon 112 (e.g., having first layer 118A, second layer 118B, and third layer 118C). In some examples, dip coating enables the addition of a relatively soft (e.g., relative lower Shore D hardness) outermost layer (e.g., third layer 118C) of balloon 112, which can enable stent retention and / or attachment of one or more sensors 142 to balloon 112 as discussed throughout this disclosure.

[0112] In examples in which dip coating is used to form one or more layers (e.g., outermost layers) of balloon 112, sensor 142 can be attached to balloon 112 prior to the dip coating process. For example, sensor 142 can be attached to an intermediately formed balloon 112 including a first portion of layers (first layer 118A and second layer 118B), and subsequently dip coated to form a second portion of outer layers (e.g., third layer 118C) radially outward of the first portion of layers (first layer 118A and second layer 118B) and sensor 142. In some examples, the dipcoating process enables mechanical fixation of one or more of sensors 142 to balloon 112 (e.g., because sensors 142 is sandwiched between two or more layers of balloon 112, such as between second layer 118B and third layer 118C). In some examples, a subsequent process removes material, such as material added via dip coating (e.g., at least a portion of third layer 118C), around sensor 142, such as to enable sensor 142 to measure relevant parameters radially outside of balloon 112. Such removal of material can expose a radially outermost portion of sensor 142 (e.g., relative to central longitudinal axis 111) to the environment radially outside of balloon 112. The process to remove material around sensor 142, such as material added via dip coating over (e.g., radially outside of) sensor 142, can include one or more of laser ablation, chemical ablation, machining, femtosecond laser, and / or another suitable process.

[0113] Balloon 112 can include any suitable material or combination of materials. As discussed herein, the term “material” can include a single chemical element and / or a chemical compound of different elements (e.g., having a fixed ratio and / or a fixed ratio range for the different elements) and / or a mixture of compounds. Balloon 112 may be constructed of one or more compliant, semi-compliant or non-compliant materials, such as one or more polymer materials such as, but not limited to, polyurethane, nylon, polyethylene, PET, and / or the like. In some examples, one or more layers of balloon 112 include, but are not limited to, one or more polyamides such as Grilamid® (available from Entec Polymers), VESTAMID® (available from Evonik Industries AG). In some examples, one or more layers of balloon 112 include one or more block copolymers such as Pebax® (available from Arkema S.A.), and / or other thermoplastic elastomers. Suitable Pebax variations include one or more of 4333 Pebax, 5533 Pebax, 6333 Pebax, 7033 Pebax, 7433 Pebax, and / or suitable mixture or sub-mixtures thereof inDocket No.: A0012639W001 / 1241-321W001 any suitable ratio(s). In some examples, one or more layers of balloon 112 include Onyx®, including 63 / 70 Onyx blend. In some examples, balloon 112 (e.g., the body of balloon 112) includes silicone.

[0114] Each of first layer 118A, second layer 118B, and third layer 118C of balloon 112 can include common or different materials having the associated properties (e.g., Shore D hardness) discussed throughout this disclosure. In some examples, first layer 118A of balloon 112 includes a first material (e.g., 6333 Pebax, 7033 Pebax, and / or 7433 Pebax) and second layer 118B of balloon 112 includes a second material different than the first material. In some examples, second material of second layer 118B includes, but is not limited to, one or more of nylon polymers (e.g., nylon 6, nylon 6,6, nylon 11, nylon 12, and / or the like), Aesno®, Vestamid®, Aseno polymers, polyamides (e.g., Grilamid® Polyamide), plasticizers (e.g., phthalate esters), and / or a suitable mixture thereof. In some examples, second layer 118B is a non-compliant layer.

[0115] In some examples, third layer 118C includes a third material different than the second material of second layer 118B. In some examples, the third material of third layer 118C includes one or more of 6333 Pebax, 5533 Pebax, 4533 Pebax, 63 / 70 Onyx blend, and / or any suitable mixture or sub-mixture thereof. In some examples, the third material of third layer 118C and the first material of first layer 118A are the same (e.g., both the first layer 118A and the second layer 118B include at least one common material and / or entirely the same material, such as Pebax 6333). In some examples, the third material of third layer 118C and the first material of first layer 118A are different. As an illustrative example in which the third material of third layer 118C and the first material of first layer 118A are different, the first material of first layer 118A can include 6333 Pebax and the third material of third layer 118C can include 5533 Pebax, 4533 Pebax, and / or 63 / 70 Onyx blend.

[0116] Balloon 112 can include a suitable wall thickness Tl. As shown in FIG. 1C, wall thickness Tl is a single wall thickness, and includes the combined thickness of each of first layer 118A, second layer 118B, and third layer 118C. As balloons are typically measured by double wall thickness (DWT), the double wall thickness of balloon 112 is two times Tl (2T1). The double wall thickness of balloon 112 (2T1) can be sufficient (e.g., sufficiently thick) to enable a suitable burst pressure needed for sufficient stent expansion, while also being sufficient thin to enable balloon 112 to have sufficient maneuverability within blood vessel 102 of patient 106. In some examples, balloon 112 (e.g., which can include each of first layer 118A, second layer 118B, and third layer 118C) defines a double wall thickness (DWT) of less or equal to than 0.0015 inches. In some examples, balloon 112 defines a double wall thickness of less or equal to than 0.0014 inches. In some examples, balloon 112 defines a double wall thickness of less or equal to than 0.0013 inches. In some examples, balloon 112 defines a double wall thicknessDocket No.: A0012639W001 / 1241-321W0010.0012 inches to 0.0014 inches. Such double wall thickness values to have sufficiently high burst pressure while maintaining maneuverability of balloon 112 within blood vessel 102 of patient 106.

[0117] Although the example of FIG. 1C illustrates balloon 112 of catheter system 108 as having three layers (e.g. first layer 118A, second layer 118B, and third layer 118C), balloon 112 can include more layers. For example, in some examples, balloon 112 includes more than one radially intermediate layer besides second layer 118B. In general, while the examples discussed herein primarily include three layers (e.g., otherwise referred to herein as tri-layer), balloon 112 can include two, three, four, five, or more layers.

[0118] Although not shown in the examples of FIG. 1A, FIG. IB, and / or FIG. 1C, medical device system 100, including catheter system 108, can include one or more additional sensors and / or energy delivery elements (e.g., energy delivery elements configure to delivery therapeutic energy to treat one or more medical conditions). Additional sensors can include one or more electrodes, optical sensors, temperature sensors, ultrasound sensors and / or ultrasound transducers, accelerometers, flow sensors, or a combination thereof. Energy delivery elements can include one or more electrodes configured to transmit electrical stimulation therapy, radiofrequency (RF) energy, pulsed field (PF) energy, or other types of energy. Additionally or alternatively, energy delivery elements can include ultrasound transducers configured to receive and / or transmit ultrasound energy. Such energy delivery elements can be affixed to and / or carried by balloon 112 using similar techniques as are described with respect to sensors 142. Applications for use of catheter system 108 with energy delivery elements include renal denervation, cardiac ablation, revascularization, and / or other medical procedures where energy is delivered to tissue from an endovascular location.

[0119] In some examples, catheter system 108 can additionally or alternatively include one or more sensors and / or therapy deliver elements along elongated body 110, either within the area defined by balloon 112, as well as proximal to and / or distal to balloon 112 along elongated body 110.

[0120] FIG. ID, FIG. IE, and FIG. IF illustrate experimental test results corresponding to various parameters for different balloons constructed according to the principles of this disclosure. In each of FIG. ID, FIG. IE, and FIG. IF, samples for which various parameters were measured include a two-layer control balloon sample 190, a commercial stent delivery balloon reference sample 191, as well as four different three-layer balloon samples (e.g., sample 192, sample 193, sample 194 and sample 195) constructed according to Table 1 below. Each of sample 192, sample 193, sample 194, and sample 195 can be an example of balloon 112 discussed in connection with FIG. 1 A, FIG. IB, and FIG. 1C. In each of FIG. ID, FIG. IE, andDocket No.: A0012639W001 / 1241-321W001FIG. IF, multiple of each type of sample were tested in order to construct the dot-and-whisker type data markers as shown.Table 1

[0121] FIG. ID includes a graph 180 illustrating double wall thickness values for each of two-layer control balloon sample 190, commercial stent delivery balloon reference sample 191, as well as experimental sample 192, sample 193, sample 194 and sample 195 constructed according to Table 1. FIG. IE includes a graph 182 illustrating burst pressure values for each of two-layer control balloon sample 190, commercial stent delivery balloon reference sample 191, as well as experimental sample 192, sample 193, sample 194 and sample 195. As can be seen by the experimental results of FIG. IE, each of experimental sample 192, sample 193, sample 194 and sample 195 had a similar or greater bust pressure as compared to commercial stent delivery balloon reference sample 191 while having a relatively lower double wall thickness (DWT) as compared to commercial stent delivery balloon reference sample 191 (e.g., as shown in FIG. ID). Said another way, each of experimental sample 192, sample 193, sample 194 and sample 195 achieved similar or greater burst performance while having lower double wall thickness values (e.g., about 24 percent to about 30 percent lower double wall thickness values).

[0122] FIG. IF includes a graph 184 illustrating determined hoop stress values for each of two-layer control balloon sample 190, commercial stent delivery balloon reference sample 191, as well as experimental sample 192, sample 193, sample 194 and sample 195. A mean outer diameter (OD) for each sample type was determined in order to evaluate and determine hoop stress. As can be seen by the experimental results of FIG. IF, each of experimental sample 192, sample 193, sample 194 and sample 195 had a similar or greater determined hoop stress as compared to commercial stent delivery balloon reference sample 191.

[0123] FIG. 2 is a functional block diagram illustrating components of an example device 130, which is configured to receive and process signals related to catheter system 108, as well as output information and control one or more operations related to catheter system 108. As described above, device 130 is configured to receive and process signals from the one or moreDocket No.: A0012639W001 / 1241-321W001 sensors 142. Device 130 includes processing circuitry 30, memory 32, signal generation circuitry 34, sensing circuitry 36, telemetry circuitry 38, and power source 40. Although processing circuitry 30, signal generation circuitry 34, sensing circuitry 36, and telemetry circuitry 38 are described herein as separate components, one or more functionalities may be attributed generally to the processing capability of device 130. For example, functionalities of signal generation circuitry 34, sensing circuitry 36, and telemetry circuitry 38 may herein be generally described as a functionality of processing circuitry 30. In some examples, device 130 includes user interface 132 (as described in connection with FIG. 1 A), as well as suitable hardware and / or software configuration generating and presenting information via user interface 132. Any of the functionalities of device 130 described in this disclosure can be attributed to processing circuitry 30, alone and / or in combination with any of memory 32, signal generation circuitry 34, sensing circuitry 36, telemetry circuitry 38, power source 40, and / or user interface 132.

[0124] Signal generation circuitry 34 includes any suitable configuration (e.g., hardware) configured to generate signals (e.g., electrical signals such as current or voltage, as other types of signals) to and / or between one or more sensors 142. Although primarily described in the context of electrical signals, signal generation circuitry 34 may be configured to deliver any suitable type of signal (e.g., electrical, acoustic, etc.) for determining information about blood vessels and / or stents. Processing circuitry 30 is configured to control signal generation circuitry 34 to generate signals. Processing circuitry 30 may be configured to control signal generation circuitry 34 to generate signals according to a predefined program, which may define one or more of an amplitude, duration, pulse rate, or another suitable signal parameter. The generated signals may be of any suitable form, such as pulses or continuous-time signals (e.g., sine waves). As an example in which processing circuitry 30 (e.g., via signal generation circuitry 34) applies a current to sensors 142, sensors 142 may output a resulting voltage signal (e.g., which can change based on the amount of pressure and / or force applied to sensors 142). In this way, processing circuitry 30 may be configured to apply an electrical signal (e.g., current signal and / or voltage signal) to sensors 142 to induce an output signal (e.g., voltage signals) in the sensors 142. In other examples, the resulting signal from sensors 142 may be one or more of the other signals described herein (e.g., a resulting current from an applied voltage).

[0125] Sensing circuitry 36 is configured to receive, via sensors 142, one or more signals for determination of information, including one or more forces and / or pressures applied by stent 160 or blood vessel wall 104 against balloon 112 including sensors 142. Sensing circuitry 36 may include any sensing hardware configured to receive signals from sensors 142, which may include a resulting voltage from sensors 142 based on the electrical signal applied to sensors 142 by signal generation circuitry 34. Processing circuitry 30 may receive, alone or in combination withDocket No.: A0012639W001 / 1241-321W001 sensing circuitry 36, the resulting signals from sensors 142. In some examples, processing circuitry 30 additionally receives one or more additional signals, including signals indicative of temperature, for determination of information, including morphology of lesion 105 of blood vessel 102, and / or force and / or pressure values sensed by sensors 142 of balloon 112.

[0126] In some examples, processing circuitry 30, alone or in combination with the sensing circuitry 36, determines, based on the received signals from sensors 142, pressure values and / or force values applied by stent 160 or blood vessel wall 104 against balloon 112 (as well as sensors 142). For example, in some examples, processing circuitry 30 is configured to receive resulting voltage values from sensors 142 and determine pressure values by applying the resulting voltage values to an equation, a model, a lookup table, and / or another relational method to determine pressures and / or forces. In some examples, the equation, the model, and / or the lookup table relates signals received from sensors 142 (e.g., measured and / or recorded voltage values) from sensors 142 to pressure values and / or force values.

[0127] In some examples, processing circuitry 30 is configured to generate a map of pressure values and / or map of force values using known locations of sensors 142 relative to balloon 112. In some examples, memory 32 stores the predetermined and / or known location of sensors 142 such that processing circuitry 30 can access such predetermined locations and generate the map of pressure values and / or map of force values, at least in part, with the predetermined and / or known location of sensors 142.

[0128] In some examples, the processing circuitry 30 is configured to determine and / or generate for output, a shape (e.g., a geometry, including a cross-sectional shape at one or more locations) of stent 160 based on the one or more force values and / or pressure values. For example, in some examples, processing circuitry 30 determines that stent 160 defines a circular shape (e.g., cross-sectional shape) at one or more locations (e.g., axial locations along balloon 112 and / or stent 160) based on a measured uniform or relatively uniform force and / or pressure around the circumference of balloon 112 (e.g., as measured by sensors 142). In some examples, processing circuitry 30 determines that stent 160 defines a non-circular shape (e.g., cross- sectional shape) at one or more locations (e.g., axial locations along balloon 112 and / or stent 160) based on a measured non-uniform force and / or pressure around the circumference of balloon 112 (e.g., as measured by sensors 142). In some examples, processing circuitry 30 generates for output (e.g., via user interface 132) indications of the determined shape (e.g., determined cross-sectional shape and / or geometry) of stent 160 (e.g., a two-dimensional or three- dimensional representation of a determined shape of stent 160). Such information can enable a clinician to target and / or selectively expand particular portions of stent 160 (e.g., a distal portion, a proximal portion, or the like) to improve the apposition of stent 160 in such portions of stentDocket No.: A0012639W001 / 1241-321W001160. By selectively expanding only portions of stent 160 to reach an adequate level of apposition, over-expansion of adequately apposed portions of stent 160 can be reduced and / or entirely avoided.

[0129] In examples where processing circuitry 30 is configured to apply a signal (e.g., resulting voltage signal values) from sensors 142 to a model to determine forces and / or pressures, the model can a relationship between the one or more signal values and the one or more force values and / or pressures values. For example, the model may include a include a predefined equation relating the one or more signal values (e.g., voltage signal values) and the force values and / or pressures values. For example, the model may use sensed information and / or user input information to determine force values and / or pressures values applied to sensors 142 (and thus also to balloon 112, which can be based on balloon expanding against vessel wall 104 and / or stent 160).

[0130] In some examples, where processing circuitry 30 is configured to apply received signals from sensors 142 to a model to determine other relevant parameters (e.g., pressure values, force values, levels of stent expansion, levels of stent apposition, and / or other relevant parameters), the model may include an artificial intelligence (Al) or machine learning (ML) model. Additionally or alternatively, processing circuitry 30 is configured to apply signals indicative of lesion morphology to an Al model or ML model to determine one or more measures of lesion morphology. In some examples, the Al model or ML model includes one or more of a statistical machine learning model, deep learning model (e.g., neural network), a physics informed neural network (e.g., that includes equations relating changes in pressure and / or force as measured by sensors 142 to dimensions of balloon 112, a stent, blood vessel 102 and / or dimensions or measures of other relevant structures). In some examples, the Al model or ML model is configured to output information (e.g., force and / or pressure values, as well as dimensions of balloon 112, a stent (e.g., stent 160), blood vessel 102 and / or other relevant structures) based on one or more inputs (e.g., voltage signal values and / or other signals from sensors 142). In some examples, the Al model is trained (e.g., via supervised, semi-supervised, unsupervised, or reinforcement learning) on clinical data or other experimental data. For example, the Al model may be trained with data relating voltage signal values to force and / or pressure values, dimensions of balloon 112, a stent, blood vessel 102 and / or other relevant structures, and / or morphological data of lesions (e.g., similar to lesion 105) of blood vessels from previous procedures and / or experiments (e.g., data measured or verified with other measurement modalities, including IVUS and / or OCT). In some examples, the Al model or ML model is configured to output the force and / or pressure values, dimensions of balloon 112, a stent, blood vessel 102 and / or other relevant structures, and / or morphological data of one or more lesions ofDocket No.: A0012639W001 / 1241-321W001 blood vessel 102. In some examples, the Al model or ML model is additionally configured to output a confidence score indicative of a confidence of the output. The confidence score may indicate an accuracy of the output.

[0131] In some examples, the model includes reference information (e.g., reference diameters) for use in determining additional information (e.g., degrees of stent expansion and stent apposition) based on the measured pressures and / or forces. Reference information, including diameters may include and / or be based on previous measurements of a blood vessel (e.g., before stent deployment), and / or a characterized (nominal) stent size. In some examples, an output of the model (e.g., resulting from the one or more voltage signal values applied to the model) includes the one or more dimensions (e.g., diameters) of balloon 112 and / or blood vessel 102 and / or stent 160.

[0132] In some examples, processing circuitry 30 determines, based on a determined diameter of stent 160 as expanded and the reference diameter of stent 160, a degree of stent expansion. For example, a reference diameter for a particular stent may be nominal or desired diameter, such as 5 millimeters (mm), and the determined diameter can include the actual or estimated diameter of the stent (e.g., 3 mm, 5 mm, 7 mm, etc.). By comparing the reference diameter for the stent and the determined diameter, the degree of stent expansion can be expressed qualitatively (e.g., under-expanded, optimally expanded, over-expanded, etc.) and / or quantitatively. For example, for a particular stent with a reference diameter of 5 mm, a 3 mm determined expanded diameter may indicate under-expansion, a 5 mm (or nearly 5mm) determined expanded diameter may indicate optimal expansion, and a 7 mm determined expanded diameter may indicate over-expansion. As another example, the degree of stent expansion may be a percentage of the reference diameter of the stent (e.g., 30 percent, 40 percent, 50 percent, 60 percent, 70 percent, 80 percent, 90 percent, 100 percent, 110 percent, 120 percent etc.).

[0133] In some examples, processing circuitry 30 determines a minimum value, maximum value, average, mean, standard deviation, or another statistical measure from multiple determined values (e.g., pressure values and / or force values) or related values (e.g., values of the degree of stent expansion and / or values of the degree of stent apposition). For example, processing circuitry 30 may determine a minimum or maximum pressure and / or force applied to balloon 112. Such minimum or maximum pressures and / or forces, or other values, may be output to a user (e.g., a clinician) as described elsewhere in this disclosure.

[0134] Further examples of clinically relevant measures and indices which processing circuitry 30 may be configured to determine include one or more of a lesion length, dissection of lesion 105 or blood vessel 102 (e.g., medial dissection), and / or other clinically relevantDocket No.: A0012639W001 / 1241-321W001 information. These other clinically relevant measures may be performed by expanding balloon 112 against the vessel wall 104 of blood vessel 102, such as before stent placement.

[0135] In some examples, processing circuitry 30, alone or in combination with the sensing circuitry 36, determines an indication of a morphology of lesion 105 of blood vessel 102 based on received signals from sensors 142 (e.g., signals that indicate one or more force and / or pressure values). In some examples, a clinician expands balloon 112 against vessel wall 104 including lesion 105 such that reaction forces and / or pressures of lesion 105 are applied to the sensors 142 (e.g., such as during a pre-dilation procedure). In some examples, processing circuitry 30 compares such reaction to a predetermined ranges of force and / or pressure values corresponding to lesions having particular morphological characteristics. For example, in some examples, processing circuitry 30 is configured to classify lesion 105 as a calcific lesion, a soft lesion (e.g., lipid based), a fatty lesion, a fibrous lesion, and / or another type of lesion based on signals that indicate one or more force values and / or pressure values. In some examples, relatively higher force values and / or pressure values determined by processing circuitry 30 correspond to harder and / or calcific lesions (e.g., which can indicate that the lesion is not deforming in response pressure applied by balloon 112). In some examples, relatively lower force and / or force values determined by processing circuitry 30 correspond to softer lesions (e.g., which can indicate that the lesion is deforming in response pressure applied by balloon 112). In examples in which multiple of sensors 142 are positioned axially along and / or around balloon 112, processing circuitry may be configured to determine, based on signals from the sensors 142, which portions of lesion 105 are more calcific (e.g., harder) as compared to other portions of lesion 105. Other morphological information of lesions may include one or more of concentricity or eccentricity, tortuosity, regularity or irregularity of contour, absence or presence of thrombus, ostial or non- ostial, as well as other relevant measures and indices. Morphological information may be determined in accordance with The American College of Cardiology / American Heart Association (ACC / AHA) lesion morphology classification and / or the subsequent modified ACC / AHA classification.

[0136] In some examples, processing circuitry 30 is configured to determine a size and / or other dimensional characteristics (e.g., length, eccentricity, and / or the like) of lesion 105 based on signals from sensors 142.

[0137] Once processing circuitry 30 has determined one or more force values and / or pressure values (e.g., including a map of force values and / or pressure values) based on received signals from sensors 142, processing circuitry 30 may generate, for output, an indication of the force values and / or pressure values (e.g., including an indication of map of force values and / or pressure values). For example, in some examples, processing circuitry 30 is configured toDocket No.: A0012639W001 / 1241-321W001 generate, for output (e.g., via a display, such as user interface 132 of device 130) a numerical representation (e.g., a value) of the one or more force values and / or pressure values. In some examples, processing circuitry 30 is configured to generate, for output, other determined values, as have been described herein, including the degree of stent expansion, the degree of stent apposition, and / or of the like. In examples in which device 130 determines a shape of balloon 112 and / or stent 160, processing circuitry 30 may generate, for output, one or more indications of a shape (e.g., a cross-sectional shape) of balloon 112 and / or of stent 160. In examples in which device 130 determines morphology of lesion 105 of blood vessel 102, processing circuitry 30 may be configured to generate, for output, an indication of the morphology of blood vessel 102 (e.g., including an indication whether lesion 105 is a calcific lesion or a soft lesion). Such an indication of morphology of lesion 105 can enable a clinician to make other clinically relevant decisions (e.g., whether to perform a stent delivery and expansion procedure, whether to perform an atherectomy procedure, and / or whether to take another course of action).

[0138] In some examples, processing circuitry 30 is configured to output, e.g., via user interface 132, a graphical representation (e.g., an image, picture, schematic representation, etc.) of blood vessel 102, other anatomical structures (e.g., a lesion, plaque, a blood vessel wall, and / or the like), stent 160, and / or balloon 112. Further, in some examples, processing circuitry 30 is configured to overlay one or more determined values (e.g., force values, pressure values, maps of force values, maps of pressure values) with or over the graphical representation of blood vessel 102, other anatomical structures (e.g., a lesion, plaque, a blood vessel wall, and / or the like), stent 160, and / or balloon 112. For example, processing circuitry 30 may overlay force values, pressure values, and / or other indications of force values, pressure values over a portion of a graphical representation of blood vessel 102, stent 160, other anatomical structures (e.g., a lesion, plaque, a blood vessel wall, and / or the like), and / or balloon 112 that corresponds to the particular determined values (e.g., at the location of stent 160 where the particular force value and / or pressure value occurs).

[0139] The indication of the one or more determined force values and / or pressure values applied by and / or against balloon 112 and / or the blood vessel 102 and / or stent 160 may enable a clinician to make a clinically relevant decision or confirm efficacy of a previous treatment. For example, the indication of the force values and / or pressure values (including a map of force values, map of pressure values, and / or the like) and / or other determined values are determined with instruments a clinician would already be using (e.g., a stent delivery catheter or post-dilation catheter), which may reduce and / or eliminate the need for other instruments (e.g., IVUS and OCT) and / or decrease procedure time. For example, a clinician may confirm an acceptable expansion and / or apposition of stent 160 against a vessel wall 104. As another example, aDocket No.: A0012639W001 / 1241-321W001 clinician may decide that further intervention is necessary based on a level of apposition of stent 160 being below a particular threshold and / or an indication of an area of malapposition of stent 160. In cases where further intervention is necessary, a clinician may further expand stent 160 with the same balloon catheter (e.g., including stent 160) used to determine the force values and / or pressure values. In this way, the need for additional imaging and / or imaging systems for determining force values and / or pressure values is reduced and / or eliminated given the multifunctional catheter system 108 according to this disclosure.

[0140] In some examples, processing circuitry 30 is configured to generate, for output, one or more recommendations to a user (e.g., clinician) based on determined information (e.g., one or more force and / or pressure values, a map of force and / or pressure values, and / or other determined information). For example, in some examples, processing circuitry 30 is configured to generate for output (e.g., on user interface 132), one or more of a recommended position for catheter system 108, such as a position of balloon 112 in relation to blood vessel 102, a recommended inflation pressure or pressure change (e.g., increase or decrease) to balloon 112, a recommended amount to expand stent 160 (e.g., a recommended diameter to expand stent 160 to), and / or another clinically relevant recommendation. In some examples, such recommendations may facilitate a clinician’s decision to move catheter system 108 (including balloon 112) within blood vessel 102. In some examples, processing circuitry 30 is configured to output a recommendation to move stent 160 (e.g., to a new location within blood vessel 102 for further expansion) based on the determined information (e.g., one or more force and / or pressure values, a map of force and / or pressure values, and / or other determined information). In some examples, such recommendations may facilitate a clinician’s decision to further inflate and / or deflate balloon 112 (e.g., for further expansion of a stent or for further compressing balloon 112 against vessel wall 104). In some examples, such recommendation may facilitate a clinician’s decision to take other appropriate course of action, including (but not limited to), delivery of additional stents, introducing a drug into blood vessel 102, and / or introducing another medical device into blood vessel 102.

[0141] Although medical device system 100 of FIG. 1 A is primarily described in the context of manual inflation via fluid inlet 148, device 130 (including processing circuitry 30) may be able to control (e.g., automatically control) inflation of balloon 112. For example, device 130 (e.g., processing circuitry 30) may be configured to receive one or more inputs including one or more measured force and / or pressure values, a level of stent expansion and / or apposition (e.g., a desired or target level and / or degree of stent expansion and / or apposition), or another relevant value, and inflate (e.g., automatically inflate) balloon 112 based on the one or more inputs.Docket No.: A0012639W001 / 1241-321W001

[0142] In some examples, sensing circuitry 36 is additionally or alternatively configured to sense a physiological parameter of a patient including temperature, pressures, sounds, light, infrared signals such as via one or more electrodes, sensors (e.g., optical receivers, pressure sensors) or the like. The one or more electrodes and / or sensors be the same or different from plurality of sensors 142 configured to receive signals via signal generation circuitry 34. Processing circuitry 30 can use the sensed physiological signals to further assess information about blood vessel 102 and / or stent 160. For example, sensing circuitry 36 may receive signals indicative of temperature (e.g., via a temperature sensor within a blood vessel). In some examples, processing circuitry 30 uses temperature values for determination of morphological information.

[0143] In some examples, sensing circuitry 36 and / or processing circuitry 30 includes signal processing circuitry configured to perform any suitable analog conditioning of the sensed physiological signals. For example, sensing circuitry 36 may communicate to processing circuitry 30 an unaltered (e.g., raw) signal. Processing circuitry 30 may be configured to modify a raw signal to a usable signal by, for example, filtering (e.g., low pass, high pass, band pass, notch, or any other suitable filtering), amplifying, performing an operation on the received signal (e.g., taking a derivative, averaging), performing any other suitable signal conditioning (e.g., converting a current signal to a voltage signal), or any combination thereof. In some examples, the conditioned analog signals may be processed by an analog-to-digital converter of processing circuitry 30 or other component to convert the conditioned analog signals into digital signals. In some examples, processing circuitry 30 may operate on the analog or digital form of the signals to separate out different components of the signals. In some examples, sensing circuitry 36 and / or processing circuitry 30 may perform any suitable digital conditioning of the converted digital signals, such as low pass, high pass, band pass, notch, averaging, or any other suitable filtering, amplifying, performing an operation on the signal, performing any other suitable digital conditioning, or any combination thereof. Additionally or alternatively, sensing circuitry 36 may include signal processing circuitry to modify one or more raw signals and communicate to processing circuitry 30 one or more modified signals.

[0144] Although shown as part of device 130 in FIG. 2, in other examples, sensing circuitry 36 can be a part of a device separate from device 130. For example, sensing circuitry 36 can be included in handle portion 150 of catheter system 108.

[0145] Processing circuitry 30, as well as other processors, processing circuitry, controllers, control circuitry, and the like, described herein, may include any combination of integrated circuitry, discrete logic circuitry, analog circuitry, such as one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), or field-programmableDocket No.: A0012639W001 / 1241-321W001 gate arrays (FPGAs). In some examples, control circuitry may include multiple components, such as any combination of one or more microprocessors, one or more DSPs, one or more ASICs, or one or more FPGAs, as well as other discrete or integrated logic circuitry, and / or analog circuitry.

[0146] Memory 32 is configured to store program instructions, such as software, which may include one or more program modules, which are executable by processing circuitry 30. When executed by processing circuitry 30, such program instructions may cause processing circuitry 30 to provide the functionality ascribed to processing circuitry 30 herein. The program instructions may be embodied in software and / or firmware. Memory 32 may include any volatile, nonvolatile, magnetic, optical, or electrical media, such as a random-access memory (RAM), readonly memory (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flash memory, or any other digital media.

[0147] Processing circuitry 30 is configured to control telemetry circuitry 38 to send and receive information. Telemetry circuitry 38, as well as telemetry modules in other devices including an external computing device or an external user interface (e.g., display), may accomplish communication by any suitable communication techniques, such as radiofrequency (RF) communication techniques.

[0148] Power source 40 is configured to deliver operating power to various components of device 130. Power source 40 may include a rechargeable or non-rechargeable battery and a power generation circuit to produce the operating power. Power source 40 may be configured to deliver enough power for determining force and / or pressure values applied to sensors 142 carried by balloon 112.

[0149] FIG. 3 A and FIG. 3B illustrates an example balloon 312. Balloon 312 can be example of balloon 112 of FIG. 1 A, FIG. IB, and FIG. 1C. As illustrated in the example of FIG. 3B, balloon 312 is configured to receive a sensor 342, e.g., such that sensor 342 can be mechanically coupled to and carried by balloon 312. In some examples, as illustrated in FIG. 3B, a conductor wire 344 is electrically coupled and / or mechanically coupled to sensor 342 and configured to connect sensor 342 to circuitry (e.g., processing circuitry, sensing circuitry, therapy generation circuitry, and / or other suitable circuitry discussed throughout this disclosure). FIG. 3C, FIG. 3D, and FIG. 3E illustrate example configurations of balloon 312 and an elongated body 310 that enable conductor wire 344 to extend from sensor 342 to a more proximal location (e.g., proximally of balloon 312 and along elongated body 310, which may be a catheter shaft). Elongated body 310 may be an example of elongated body 110 of FIG. 1 A and FIG. IB.

[0150] In each of the examples of FIG. 3A, FIG. 3B, FIG. 3C, FIG. 3D, and FIG. 3E, balloon 312 includes a body portion 314 (e.g., extending between a body proximal end 314A and bodyDocket No.: A0012639W001 / 1241-321W001 distal end 314B as illustrated in FIG. 3 A and FIG. 3B). In some examples, balloon 312 includes at least a proximal cone portion 315 positioned proximally of body portion 314. Balloon 312 includes at least a proximal waist portion 316 positioned proximally of proximal cone portion 315. Body portion 314, proximal cone portion 315, and proximal waist portion 316 may be examples of body portion 114, proximal cone portion 115A, and proximal waist portion 116A of FIG. IB, respectively. Balloon 312 defines a central longitudinal axis 311 extending through a radial center of balloon 312. Central longitudinal axis 311 can also extend through a radial center of elongated body 310.

[0151] In some examples, as illustrated in the example of FIG. 3 A, balloon 312 (e.g., at least body portion 314 of balloon 312) defines at least at least one pocket 346. In some examples, at least a radially outermost layer of balloon 312 (e.g., such as third layer 118C as shown in FIG. 1C), defines pocket 346. In some examples, pocket 346 is a recess from an outermost surface of balloon 312. In some examples, as illustrated in the example of FIG. 3B, pocket 346 is configured to receive a sensor 342. Sensor 342 is an example of sensors 142 of FIG. 1 A, FIG. IB, and FIG. 1C. In some examples, a radially outermost layer of balloon 312 (e.g., third layer 118C of FIG. 1C) defines pocket 346 without impacting other radially adjacent layers of balloon 112 (e.g., either of first layer 118A or second layer 118B of FIG. 1C). Such a configuration can enable balloon 312 to carry one or more of sensor 342 while limiting impact to physical characteristics of balloon 312 (e.g., including maximum burst pressure and / or fatigue resistance of balloon 312).

[0152] Pocket 346 can be formed from any suitable process or combination of processes. For example, after balloon 312 is formed via a suitable molding process, a portion of material from a radially outermost layer of balloon 312 (e.g., third layer 118C of FIG. 1 C) can be removed via a suitable process (e.g., machining, femtosecond laser, and / or the like) to form pocket 346. In some examples, pocket 346 is formed during the balloon forming (e.g., molding) process, e.g., a balloon mold can include a feature corresponding to the shape and size of pocket 346 such that pocket 346 is formed while balloon 312 is formed within the balloon mold.

[0153] By defining pocket 346, sensor 342 may be positioned relative to a radially outermost surface of balloon 312 such that a radially outermost surface of sensor 342 relative to central longitudinal axis 311 sits flush or nearly flush with the radially outermost surface of balloon 312 (e.g., a radially outermost surface of balloon 312 relative to central longitudinal axis 311). In some examples, sensor 342 sits flush or nearly flush with the radially outermost surface of balloon 312 when balloon 312 is in the collapsed (e.g., deflated) configuration. Such positioning of sensor 342 relative to balloon 312 (e.g., flush or nearly flush with an outermost surface of balloon 312) can enable balloon 312 with one or more of sensor 342 to be more easily navigatedDocket No.: A0012639W001 / 1241-321W001 through vasculature of patient 106 (e.g., as compared to balloon catheter systems in which sensors are mounted to a surface of a balloon without a pocket and sit proud of a radially outermost surface of the balloon).

[0154] In some examples, such as when balloon 312 is in the expanded (e.g., inflated configuration), balloon 312 (e.g., including pocket 346) can be sized, shaped, and / or otherwise configured such that sensor 342 sits slightly proud of a radially outermost surface of balloon 312. For example, in some examples, a radially outermost surface of sensor 342 can extend radially outward from a radially outermost surface of balloon 312 such that sensor 342 is positioned slightly proud of the radially outermost surface of balloon 312 (e.g., when balloon 312 is in the expanded configuration). Such a configuration of balloon 312 and sensor 342 can enable sensor 342 to contact one or more of a stent (e.g., stent 160 of FIG. IB) and / or a vessel wall of a blood vessel (e.g., blood vessel wall 104 of blood vessel 102), e.g., when balloon 312 is in the expanded configuration.

[0155] One or more of sensor 342 can be secured to balloon 312 using any suitable method. In some examples, sensor 342 is secured to a surface of balloon 312 (e.g., a radially outward surface of balloon 312 in pocket 346) via one or more of adhesive, crimp, thermal reflow (e.g., of polymer material in and / or around sensor 342), interference fit (e.g., interference fit between sensors 342 and one or more walls of pocket 346) and / or another suitable fixation method.

[0156] In some examples, as illustrated in the example of FIG. 3 A, balloon 312 (e.g., at least body portion 314 of balloon 312) defines at least one channel 348. In some examples, at least a radially outermost layer of balloon 312, (e.g., such as third layer 118C as shown in FIG. 1C) defines channel 348. In some examples, channel 348 extends axially (e.g., in the x-axis direction according to the orthogonal x-y-z axes of FIG. 3 A) through at least a portion of an outermost layer of balloon 112 (e.g., third layer 118C in the example of FIG. 1C). In some examples, channel 348 is configured to receive at least one of conductor wires 344, as illustrated in FIG. 3B. Channel 348 can enable electrical connection of device 130 (shown in FIG. 1A) to one or more sensors 342 via one or more conductor wires 344 while maintaining a relatively small form factor of balloon 312 (e.g., because one or more of conductor wires 344 can sit flush, nearly flush, or below the radially outermost surface of balloon 312 as balloon is navigated through vasculature of patient 106).

[0157] Channel 348 can be formed via a suitable process. For example, channel 348 can be formed similarly to and / or along with pocket 346 (e.g., during and / or after formation of balloon 312).

[0158] In some examples, as illustrated in FIG. 3B, one or more of conductor wire 344 extends within channel 348 between at least sensor 342 (which is positioned axially at a portionDocket No.: A0012639W001 / 1241-321W001 within body portion 314 of balloon 312) and body proximal end 314 A. In some examples, channel 348 can additionally or alternatively extend within proximal cone portion 315 and / or proximal waist portion 316 of balloon 312.

[0159] Each of FIG. 3C, FIG. 3D, and FIG. 3E illustrate example configurations that enable conductor wire 344 to extend from sensor 342 to a more proximal location (e.g., proximally of balloon 312 and along elongated body 310, which may be a catheter shaft). Each of FIG. 3C, FIG. 3D, and FIG. 3E include a cross-sectional view of at least balloon 312 of FIG. 3B, the cross-section taken through a radial center of balloon 312 (e.g., through central longitudinal axis 311) and parallel to a plane defined by the x-axis and y-axis according to the orthogonal x-y-z axes of FIG. 3B.

[0160] In some examples, elongated body 310 of each of FIG. 3C, FIG. 3D, and FIG. 3E is fixedly mechanically coupled to balloon 312. For example, as illustrated in each of FIG. 3C, FIG. 3D, and FIG. 3E, elongated body 310 can include an overlapping portion 370 that at least partially overlaps (e.g., axially overlaps along central longitudinal axis 311) with proximal waist portion 316 of balloon 312. In some examples, overlapping portion 370 of elongated body 310 is fixedly mechanically coupled to (e.g., bonded to) proximal waist portion 316 of balloon 312 via a suitable process (e.g., laser welding, thermal reflow, and / or the like). The configurations shown in each of FIG. 3C, FIG. 3D, and FIG. 3E enable conductor wire 344 to be routed into an interior portion of elongated body 310 (e.g., a lumen of elongated body 310 and / or within the wall of elongated body 310) such that conductor wire 344 can extend proximally along and within elongated body 310 (e.g., such as to handle portion 150 of FIG. 1A). By extending at least partially within elongated body 310, conductor wire 344 can be at least partially physically and / or electrically isolated from the environment outside of elongated body 310, which can reduce at least some mechanical forces from being applied to and / or transferred to conductor wire 344 and / or reduce the likelihood of disrupted electrical signal transmission along conductor wire 344.

[0161] In the example of FIG. 3C, overlapping portion 370 of elongated body 310 is positioned within (e.g., radially within) proximal waist portion 316 of balloon 312. In this example, starting from sensor 342, conductor wire 344 extends along (e.g., generally in the negative x-axis direction according to the orthogonal x-y-z axes of FIG. 3C) and proximally of proximal waist portion 316 of balloon 312. Once proximal of proximal waist portion 316, conductor wire 344 is turned back to extend through the annular space between proximal waist portion 316 of balloon 312 and overlapping portion 370 of elongated body 310. After extending through the annular space between proximal waist portion 316 of balloon 312 and overlapping portion 370 of elongated body 310, conductor wire 344 is turned back to extend proximally (e.g.,Docket No.: A0012639W001 / 1241-321W001 in the negative x-axis direction) within and along elongated body 310. Thus, in the example of FIG. 3C, conductor wire 344 includes at least two 180 degree turns, e.g., in order to extend along an interior portion of elongated body 310. After conductor wire 344 is routed from sensor 342 to an interior portion of elongate body 310 as shown in FIG. 3C, at least overlapping portion 370 of elongated body 310 and proximal waist portion 316 of balloon 312 can be fixedly mechanically coupled via a suitable process (e.g., laser welding, thermal reflow, and / or the like). Such mechanical coupling of elongated body 310 and proximal waist portion 316 of balloon 312 can create a seal (e.g., a fluid-tight seal) around conductor wire 344 and / or secure conductor wire 344 relative to balloon 312 and / or elongated body 310.

[0162] In the example of FIG. 3D, overlapping portion 370 of elongated body 310 is positioned outside of (e.g., radially outside of) proximal waist portion 316 of balloon 312. In this example, starting from sensor 342, conductor wire 344 extends proximally of proximal waist portion 316 of balloon 312 and through the annular space between proximal waist portion 316 of balloon 312 and overlapping portion 370 of elongated body 310. After extending through the annular space between proximal waist portion 316 of balloon 312 and overlapping portion 370 of elongated body 310 in the example of FIG. 3D, conductor wire 344 extends proximally within and along elongated body 310. After conductor wire 344 is routed from sensor 342 to an interior portion of elongate body 310 as shown in FIG. 3D, at least overlapping portion 370 of elongated body 310 and proximal waist portion 316 of balloon 312 can be fixedly mechanically coupled via a suitable process (e.g., laser welding, thermal reflow, and / or the like). Such mechanical coupling of elongated body 310 and proximal waist portion 316 of balloon 312 can create a seal (e.g., a fluid-tight seal) around conductor wire 344 and / or secure conductor wire 344 relative to balloon 312 and / or elongated body 310.

[0163] In the example of FIG. 3E, overlapping portion 370 of elongated body 310 is positioned within (e.g., radially within) proximal waist portion 316 of balloon 312. In the example of FIG. 3E, proximal waist portion 316 of balloon 312 defines a hole 343. Hole 343 can be sized, shaped, positioned, and / or otherwise configured to receive conductor wire 344 therethrough. In the example of FIG. 3E, starting from sensor 342, conductor wire 344 extends proximally along proximal waist portion 316 of balloon 312, through hole 343 and across the annular space between proximal waist portion 316 of balloon 312 and overlapping portion 370 of elongated body 310. After extending across the annular space between proximal waist portion 316 of balloon 312 and overlapping portion 370 of elongated body 310, conductor wire 344 extends proximally within and along elongated body 310. After conductor wire 344 is routed from sensor 342 to an interior portion of elongate body 310 as shown in FIG. 3E, at least overlapping portion 370 of elongated body 310 and proximal waist portion 316 of balloon 312Docket No.: A0012639W001 / 1241-321W001 can be fixedly mechanically coupled via a suitable process (e.g., laser welding, thermal reflow, and / or the like). Such mechanical coupling of elongated body 310 and proximal waist portion 316 of balloon 312 can create a seal (e.g., a fluid-tight seal) around conductor wire 344 and / or secure conductor wire 344 relative to balloon 312 and / or elongated body 310.

[0164] The examples of FIG. 3C, FIG. 3D, and FIG. 3E illustrate various examples in which conductor wire 344 is routed from sensor 342 (e.g., which may be positioned on an exterior portion of balloon 112) to an interior portion of elongated body 310. In the examples of FIG. 3C, FIG. 3D, and FIG. 3E, conductor wire 344 extends at least partially along an exterior surface (e.g., radially outward relative to central longitudinal axis 311) of balloon 312. In other examples, conductor wire 344 can be at least partially embedded within balloon 312 and / or elongated body 310, e.g., such that conductor wire 344 extends axially along and embedded within balloon 312 and / or elongated body 310.

[0165] FIG. 4A illustrates a tube 470 including a wall and defining a lumen therethrough. FIG. 4B illustrates a balloon 412, which can be formed from tube 470 via a suitable balloon molding and / or balloon blowing process. FIG. 4C illustrates a cross-sectional view of tube 470 of FIG. 4 A, the cross-section taken along the B-B section lines in the example of FIG. 4 A and facing in the negative x-axis direction according to the orthogonal x-y-z axes of FIG. 4A. FIG. 4D illustrates a cross-sectional view of the balloon 412 of FIG. 4 A, the cross-section taken along the C-C section lines in the example of FIG. 4B and facing in the negative x-axis direction according to the orthogonal x-y-z axes of FIG. 4B.

[0166] In the example of FIG. 4A, tube 470 is formed (e.g., extruded) with at least a first conductor wire 444A and a second conductor wire 444B (collectively referred to herein as conductor wires 444) at least partially embedded within the polymer matrix of tube 470 (e.g., within the wall of tube 470). For example, tube 470 can be extruded with (e.g., coextruded with) at least first conductor wire 444A and second conductor wire 444B within the polymer matrix of tube 470 (e.g., such as within third layer 418C as shown in FIG. 4C). In some examples, at least a portion of tube 470 can be formed first (e.g., e.g., at least first layer 418A and second layer 418B as shown in FIG. 4C), and each of conductor wire 444A and conductor wire 444B can be deposited (e.g., via a suitable process, such as a braiding process) over first layer 418A and second layer 418B. Third layer 418C can be added to tube 470 concurrently with and / or after each of conductor wire 444A and conductor wire 444B is deposited on first layer 418A and second layer 418B. While the example of FIG. 4A and FIG. 4C illustrates tube 470 including first conductor wire 444A and second conductor wire 444B, tube 470 can include any suitable number of conductor wires (e.g., one, two, three, four, or more conductor wires).Docket No.: A0012639W001 / 1241-321W001

[0167] Tube 470 defines a central longitudinal axis 411 extending through a radial center of tube 470 (e.g., as illustrated in the example of FIG 4A). Tube 470 can be transformed to balloon 412 by at least expanding a portion of tube 470 relative to central longitudinal axis 411. Central longitudinal axis 411 can also extend through a radial center of balloon 412 (e.g., as illustrated in the example of FIG. 4B).

[0168] As illustrated in the example of FIG. 4C, tube 470 includes at least a first layer 418A, a second layer 418B positioned radially outward of first layer 418 A, and a third layer 418C positioned radially outward of first layer 418A and second layer 418B. FIG. 4D similarly illustrates balloon 412 as including first layer 418A, second layer 418B, and third layer 418C. As illustrated, each of least first conductor wire 444A and second conductor wire 444B are embedded within third layer 418C such that material of third layer 418C surrounds (e.g., completely surrounds) each of first conductor wire 444 A and second conductor wire 444B. In examples in which one or more layers of balloon 412 completely surrounds conductor wires 444, balloon 412 can electrically insulate and / or thermally insulate conductor wires 444 from the environment inside or outside of balloon 412.

[0169] By being embedded within tube 470 prior to balloon formation, conductor wires 444 can be at least partially physically and / or electrically isolated from the environment outside of balloon 412, which can facilitate reduced mechanical forces from being applied to conductor wires 444 and / or reduce the likelihood disrupted electrical signal transmission along conductor wires 444. Further, extruding tube 470 with conductor wires 444 can reduce or eliminate the need for channels and / or specialized routing for conductor wires 444, e.g., during or after formation of balloon 412 from tube 470.

[0170] In some examples, at least a portion of conductor wire 444A and / or conductor wire 444B can be at least partially exposed (e.g., exposed to the environment surrounding conductor wire 444A and / or conductor wire 444B). The exposed portion of conductor wire 444A and / or conductor wire 444B can be mechanically and / or electrically coupled to a sensor 442. Sensor 442 may be an example of sensor 142 of FIG. 1A, FIG. IB, and FIG. 1C. For example, sensor 442 can include one or more of a pressure sensor, force sensor, and / or strain sensor. In some examples, sensor 442 is configured to determine one or more pressure values and / or force values applied to an external surface of balloon 412. In some examples, sensor 442 is configured to determine an amount of deformation and / or expansion of balloon 412.

[0171] In each of the examples of FIG. 4A, and FIG. 4B, balloon 412 includes a body portion 414 (e.g., extending between a body proximal end 414A and body distal end 414B as illustrated in FIG. 4B). In some examples, balloon 412 includes at least a proximal cone portion 415 positioned proximally of body portion 414. Balloon 412 includes at least a proximal waistDocket No.: A0012639W001 / 1241-321W001 portion 416 positioned proximally of proximal cone portion 415. Body portion 414, proximal cone portion 415, and proximal waist portion 416 may be examples of body portion 114, proximal cone portion 115A, and proximal waist portion 116A of FIG. IB, respectively. Balloon 412 defines a central longitudinal axis 411 extending through a radial center of balloon 412.

[0172] As illustrated in FIG. 4B, balloon 412 can define a pocket 446 configured to receive sensor 442. In some examples, sensor 442 (e.g., when received by pocket 446 and / or otherwise affixed to balloon 412) is mechanically and / or electrically coupled to one or more of conductor wire 444 A and conductor wire 444B. Pocket 446 can be similar to pocket 346 of FIG. 3 A and FIG. 3B (e.g., formed during and / or after the formation process that forms balloon 412). In some examples, pocket 446 is sufficiently deep (e.g., in a radial direction relative to an outer surface of balloon 412) such that sensor 442 can be positioned in pocket and mechanically and / or electrically coupled to one or more of first conductor wire 444A and second conductor wire 444B. For example, pocket 446 may be sufficiently deep within an outer layer of balloon 412 to at least partially expose a portion of one or more of first conductor wire 444A and / or second conductor wire 444B, e.g., such that one or more of first conductor wire 444A and / or second conductor wire 444B can be mechanically and / or electrically coupled to sensor 442 positioned in pocket 446. In some examples, as illustrated in FIG. 4D, sensor 442 (which may be an example of any of the sensor described in this disclosure, including sensors 142) defines a thickness (e.g., a dimension in a radial direction from the radial center of balloon 412) that is less than or equal to a thickness of the radially most outward layer of balloon 412 (e.g., third layer 418C in the example of FIG. 4D).

[0173] Although not shown in the example of FIG. 4B, one or more of first conductor wire 444A and / or second conductor wire 444B can extend proximally of balloon 412 (e.g., in the negative x-axis direction according to the orthogonal x-y-z axes of FIG. 4B). Additionally or alternatively, different conductor wires (e.g., different conductor wires as compared to first conductor wire 444A and / or second conductor wire 444B) can be mechanically and / or electrically coupled to first conductor wire 444A and / or second conductor wire 444B, e.g., such that sensor 442 can be electrically coupled to device 130 of FIG. 1A.

[0174] Although the example of FIG. 4B illustrates a single sensor 442 carried by balloon 412, in other examples, more than one of sensor 442 is carried by balloon (e.g., two, three, four, five, ten, twenty, fifty, one-hundred, or more of sensor 442). In some examples, more than one of sensor 442 is connected in series via first conductor wire 444A and / or second conductor wire 444B. For example, in some examples, more than one of sensor 442 can be axially disposed relative to central longitudinal axis 411 of balloon 412, with more than one of sensor 442Docket No.: A0012639W001 / 1241-321W001 mechanically and / or electrically coupled to first conductor wire 444A and / or second conductor wire 444B.

[0175] FIG. 5 A and FIG. 5B illustrates an example balloon 512. Balloon 512 can be example of balloon 112 of FIG. 1 A, FIG. IB, and FIG. 1C. In each of the examples of FIG. 5A and FIG.5B, balloon 512 includes a body portion 514 (e.g., extending between a body proximal end 514A and a body distal end 514B as illustrated in FIG. 5 A and FIG. 5B). In some examples, balloon 512 includes at least a proximal cone portion 515 positioned proximally of body portion 514. Balloon 512 includes at least a proximal waist portion 516 positioned proximally of proximal cone portion 515. Body portion 514, proximal cone portion 515, and proximal waist portion 516 may be examples of body portion 114, proximal cone portion 115A, and proximal waist portion 116A of FIG. IB, respectively. Balloon 512 defines a central longitudinal axis 511 extending through a radial center of balloon 512.

[0176] As illustrated in the example of FIG. 5A and FIG. 5B, balloon 512 includes a plurality of conductive elements 541. In some examples, conductive elements 541 are configured to be selectively joined via a suitable process (e.g., joined via femtosecond and / or nanosecond laser to create a sensor circuit). For example, as illustrated in the example of FIG. 5B, at least a subset (e.g., less than all) of conductive elements 541 can be joined to form a sensor circuit 542. Sensor circuit 542 can be example of, and configured similarly to, any of the example sensors described throughout this disclosure (e.g., sensor 142 of FIG. 1 A, FIG. IB, and FIG. 1 C).

[0177] In some examples, a radially outermost layer of balloon 512 includes conductive elements 541 (e.g., third layer 118C in the example of FIG. 1 C). In some examples, some layers of balloon 512 do not include conductive elements 541. For example, in some examples, radially inward layers of balloon 512 (e.g., first layer 118A and second layer 118B of FIG. 1 C) do not include conductive elements 541.

[0178] In some examples, conductive elements 541 are loaded into a material used for one or more layers of balloon 512. For example, the material used for an outermost layer of balloon 512 (e.g., third layer 118C in the example of FIG. 1 C) can be loaded with conductive elements 541. Such material including conductive elements 541 can be co-extruded with other layers to form a tube that is molded to form balloon 512. After molding of balloon 512, a subset of conductive elements 541 can be selectively joined to form sensor circuit 542, as illustrated in FIG. 5B.

[0179] Conductive elements 541 can include any suitable conductive material including, but not limited to, one or more of copper, gold, or silver, another conductive material, as well as any suitable mixtures and / or alloys thereof.

[0180] In some examples, a conductor wire (not shown in the example of FIG. 5B) is electrically coupled and / or mechanically coupled to sensor circuit 542, e.g., such as to connectDocket No.: A0012639W001 / 1241-321W001 sensor circuit 542 to circuitry (e.g., processing circuitry, sensing circuitry, therapy generation circuitry, and / or other suitable circuitry discussed throughout this disclosure).

[0181] An example technique for using a medical device is illustrated in FIG. 6. The technique is described mainly with reference to medical device system 100 of FIG. 1A, FIG. IB, and FIG. 1C, and processing circuitry 30 as discussed in connection with FIG. 2, however the technique may be applied to other medical systems in other examples.

[0182] The technique includes introducing at least a portion of a medical device (e.g., balloon 112 of catheter system 108) into vasculature (e.g., blood vessel 102) of patient 106 (600). In some examples, balloon 112 carries stent 160 as balloon 112 is navigated through vasculature of patient 106. As discussed in connection with previous examples, balloon 112 (e.g., including first layer 118A, second layer 118B, and third layer 118C) can be configured to retain stent 160 on balloon 112 because of the relatively lower Shore D hardness of third layer 118C (e.g., as compared to at least first layer 118A and second layer 118B). Additionally or alternatively, balloon 112 carries one or more sensors 142.

[0183] The technique includes advancing the medical device (e.g., catheter system 108) until balloon 112 is at or near a target location in vasculature of patient 106 (602). In some examples, a target location includes a location at or adjacent to lesion 105 of blood vessel 102. In some examples, balloon 112 is advanced until lesion 105 is positioned radially outside at least a portion of balloon 112. In examples in which stent 160 is carried by balloon 112, balloon 112 can be advanced until lesion 105 is positioned radially outside at least a portion of stent 160.

[0184] In some examples, once balloon 112 is positioned adjacent lesion 105, the technique includes expanding balloon 112. In examples in which balloon 112 carries stent 160 to the location adjacent lesion 105, expansion of balloon 112 causes expansion (e.g., radial expansion) of stent 160, e.g., such that stent 160 forces blood vessel 102 to increase to a larger inner diameter. In some examples, such as during a pre-dilation procedure, expansion of balloon 112 against a portion of blood vessel wall 104 of blood vessel 102 (e.g., a portion including lesion 105) can compress lesion 105. In examples in which balloon 112 carries one or more of sensors 142, expanding balloon 112 against lesion 105 can enable device 130 to determine, via sensors 142, one or more of a morphology, size, and / or other dimensional characteristics of lesion 105. In some examples, such as during a post-dilation procedure, expansion of balloon 112 can provide a secondary expansion to stent 160, e.g., to further expand stent 160 after a different balloon catheter was previously used to deliver and at least partially deploy and expand stent 160.

[0185] Before, during, and / or after any of the aforementioned steps, processing circuitry 30 (e.g., of device 130) can be configured to generate, for output, one or more of an indication of morphology (e.g., of lesion 105) or a map of force values and / or a map of pressure values at leastDocket No.: A0012639W001 / 1241-321W001 in part based on signals received from sensors 142. As discussed above, in some examples, processing circuitry 30 applies the received signal values from sensors 142 to one or more of an equation, a model, a lookup table, and / or another relational method that electrical signals (e.g., voltage values) from sensors 142 to pressure values and / or force values.

[0186] Before, during, and / or after any of the aforementioned steps, processing circuitry 30 can generate one or more outputs, such as for presentation via user interface 132 of device 130. In some examples, processing circuitry 30 generates, for output (e.g., such as via user interface 132 of device 130), an indication of a map of pressure values and / or a map of force values. In some examples, processing circuitry 30 generates map of pressure values and / or the map of force using known locations of sensors 142 relative to balloon 112. In some examples, processing circuitry generates, for output (e.g., such as via user interface 132 of device 130), an indication of the morphology of blood vessel 102 (e.g., which can include an indication of whether lesion 105 is a calcific lesion or a soft lesion, such as a lipid based lesion).

[0187] In some examples, processing circuitry 30 determines and / or generates other relevant measures and / or indices related to the determined force values and / or pressure values. For example, in some examples and as discussed throughout this disclosure, processing circuitry 30 determines one or more locations of malapposition of stent 160 against blood vessel wall 104 and / or one or more degrees of apposition of stent 160 against blood vessel wall 104. In some examples and as discussed throughout this disclosure, processing circuitry 30 generates, for output (e.g., such as via user interface 132 of device 130), an indication of the one or more locations of malapposition of stent 160 against blood vessel wall 104 and / or an indication of the one or more degrees of apposition of stent 160 against blood vessel wall 104.

[0188] The techniques described in this disclosure, including those attributed to medical device system 100, catheter system 108, device 130, or various constituent components, may be implemented, at least in part, in hardware, software, firmware or any combination thereof. For example, various aspects of the techniques may be implemented within one or more processors, including one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate array (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components, embodied in programmers, such as clinician or patient programmers, medical devices, or other devices. Processing circuitry, control circuitry, and sensing circuitry, as well as other processors and controllers described herein, may be implemented at least in part as, or include, one or more executable applications, application modules, libraries, classes, methods, objects, routines, subroutines, firmware, and / or embedded code, for example. In addition, analog circuits, components and circuit elements may be employed to construct one, some or all of theDocket No.: A0012639W001 / 1241-321W001 processing circuitry 30, instead of or in addition to the partially or wholly digital hardware and / or software described herein. Accordingly, analog or digital hardware may be employed, or a combination of the two.

[0189] In one or more examples, the functions described in this disclosure may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on, as one or more instructions or code, a computer- readable medium and executed by a hardware-based processing unit. The computer-readable medium may be an article of manufacture including a non-transitory computer-readable storage medium encoded with instructions. Instructions embedded or encoded in an article of manufacture including a non-transitory computer-readable storage medium encoded, may cause one or more programmable processors, or other processors, to implement one or more of the techniques described herein, such as when instructions included or encoded in the non-transitory computer-readable storage medium are executed by the one or more processors. Example non- transitory computer-readable storage media may include random-access memory (RAM), readonly memory (ROM), programmable ROM (PROM), erasable programmable ROM (EPROM), electronically erasable programmable ROM (EEPROM), flash memory, a hard disk, a compact disc ROM (CD-ROM), a floppy disk, a cassette, magnetic media, optical media, or any other computer readable storage devices or tangible computer readable media.

[0190] In some examples, a computer-readable storage medium includes a non-transitory medium. The term “non-transitory” may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in RAM or cache).

[0191] The functionality described herein may be provided within dedicated hardware and / or software modules. Depiction of different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be realized by separate hardware or software components. Rather, functionality associated with one or more modules or units may be performed by separate hardware or software components, or integrated within common or separate hardware or software components. Also, the techniques could be fully implemented in one or more circuits or logic elements.

[0192] As used herein, “about” and / or “substantially” can indicate the exact value or nearly the exact value to the extent permitted by manufacturing tolerances. “About” and / or “substantially” can also refer to a certain percentage of the recited value (e.g., within about 1%, 5%, or 10%).

[0193] This disclosure includes the following non-limiting examples.Docket No.: A0012639W001 / 1241-321W001

[0194] Example 1 : A medical device includes an elongated body configured to be introduced into a blood vessel of a patient; and an expandable structure at a distal portion of the elongated body, the expandable structure including: a first layer having a first Shore D hardness; a second layer having a second Shore D hardness and positioned radially outward of the first layer, the second Shore D hardness greater than the first Shore D hardness; and a third layer having a third Shore D hardness and positioned radially outward of the first layer and the second layer, the third Shore D hardness less than or equal to the first Shore D hardness and less than the second Shore D hardness, wherein: the third layer is configured to receive a stent such that the stent is at least partially embedded in the third layer, and / or the third layer is configured to receive one or more sensors such that the one or more sensors are at least partially embedded in the third layer.

[0195] Example 2: The medical device of example 1, wherein the second layer is directly adjacent to the first layer and the third layer is directly adjacent to the second layer.

[0196] Example 3: The medical device of any of examples 1 and 2, wherein the second Shore D hardness is greater than or equal to 70D.

[0197] Example 4: The medical device of any of examples 1 through 3, wherein the first Shore D hardness is 60D to 70D.

[0198] Example 5: The medical device of any of examples 1 through 4, wherein the expandable structure defines a double wall thickness (DWT) of less or equal to than 0.0015 inches.

[0199] Example 6: The medical device of any of examples 1 through 5, wherein the second layer is thicker than the first layer.

[0200] Example 7: The medical device of any of examples 1 through 6, wherein the first layer includes a first material and the second layer includes a second material different than the first material.

[0201] Example 8: The medical device of example 7, wherein the third layer includes a third material different than the second material.

[0202] Example 9: The medical device of example 8, wherein the third material and the first material are the same.

[0203] Example 10: The medical device of example 8, wherein the third material and the first material are different.

[0204] Example 11 : The medical device of any of examples 1 through 10, wherein the one or more sensors include a pressure sensor or a force sensor.

[0205] Example 12: The medical device of any of examples 1 through 11, wherein the third layer defines a pocket configured to receive the one or more sensors.Docket No.: A0012639W001 / 1241-321W001

[0206] Example 13: The medical device of any of examples 1 through 12, further comprising the one or more sensors and one or more conductor wires electrically coupled to the one or more sensors.

[0207] Example 14: The medical device of example 13, wherein the one or more conductor wires extend at least between the one or more sensors and a proximal portion of the elongated body.

[0208] Example 15: The medical device of any of examples 13 and 14, wherein the third layer defines a channel configured to receive at least one conductor wire of the one or more conductor wires.

[0209] Example 16: The medical device of any of examples 13 and 14, wherein a material of the third layer completely surrounds at least one conductor wire of the one or more conductor wires.

[0210] Example 17: The medical device of any of examples 13 and 14, wherein a material of the third layer includes a plurality of conductive elements, and wherein at least a subset of the plurality of conductive elements are joined to form the one or more sensors.

[0211] Example 18: A method includes introducing a medical device into vasculature of a patient, the medical device includes an elongated body configured to be introduced into a blood vessel of the patient, and an expandable structure at a distal portion of the elongated body, the expandable structure including: a first layer having a first Shore D hardness, a second layer having a second Shore D hardness and positioned radially outward of the first layer, the second Shore D hardness greater than the first Shore D hardness, and a third layer having a third Shore D hardness and positioned radially outward of the first layer and the second layer, the third Shore D hardness less than or equal to the first Shore D hardness and less than the second Shore D hardness, wherein: the third layer is configured to receive a stent such that the stent is at least partially embedded in the third layer, and / or the third layer is configured to receive one or more sensors such that the one or more sensors are at least partially embedded in the third layer; and advancing the medical device until the expandable structure is at or near a target location in the vasculature of the patient.

[0212] Example 19: The method of example 18, wherein the second layer is directly adjacent to the first layer and the third layer is directly adjacent to the second layer.

[0213] Example 20: The method of any of examples 18 and 19, wherein the second Shore D hardness is greater than or equal to 70D.

[0214] Example 21 : The method of any of examples 18 through 20, wherein the first Shore D hardness is 60D to 70D.Docket No.: A0012639W001 / 1241-321W001

[0215] Example 22: The method of any of examples 18 through 21, wherein the expandable structure defines a double wall thickness (DWT) of less or equal to than 0.0015 inches.

[0216] Example 23: The method of any of examples 18 through 22, wherein the second layer is thicker than the first layer.

[0217] Example 24: The method of any of examples 18 through 23, wherein the first layer includes a first material and the second layer includes a second material different than the first material.

[0218] Example 25: The method of example 24, wherein the third layer includes a third material different than the second material.

[0219] Example 26: The method of example 25, wherein the third material and the first material are the same.

[0220] Example 27: The method of example 25, wherein the third material and the first material are different.

[0221] Example 28: The method of any of examples 18 through 27, wherein the one or more sensors include a pressure sensor or a force sensor.

[0222] Example 29: The method of any of examples 18 through 28, wherein the third layer defines a pocket configured to receive the one or more sensors.

[0223] Example 30: The method of any of examples 18 through 29, wherein the medical device further comprises the one or more sensors and one or more conductor wires electrically coupled to the one or more sensors.

[0224] Example 31 : The method of example 30, wherein the one or more conductor wires extend at least between the one or more sensors and a proximal portion of the elongated body.

[0225] Example 32: The method of any of examples 30 and 31, wherein the third layer defines a channel configured to receive at least one conductor wire of the one or more conductor wires.

[0226] Example 33 : The method of any of examples 30 and 31, wherein a material of the third layer completely surrounds at least one conductor wire of the one or more conductor wires.

[0227] Example 34: The method of any of examples 30 and 31, wherein a material of the third layer includes a plurality of conductive elements, and wherein at least a subset of the plurality of conductive elements are joined to form the one or more sensors.

[0228] Example 35: A medical device system includes an elongated body configured to be introduced into a blood vessel of a patient; an expandable structure at a distal portion of the elongated body, the expandable structure including: a first layer having a first Shore D hardness; a second layer having a second Shore D hardness and positioned radially outward of the first layer, the second Shore D hardness greater than the first Shore D hardness; and a third layerDocket No.: A0012639W001 / 1241-321W001 having a third Shore D hardness and positioned radially outward of the first layer and the second layer, the third Shore D hardness less than or equal to the first Shore D hardness and less than the second Shore D hardness, one or more sensors at least partially embedded in the third layer; and one or more conductor wires at least partially embedded in the third layer and electrically coupled to the one or more sensors, wherein the third layer defines a pocket configured to receive the one or more sensors.

[0229] Example 36: The medical device system of example 35, wherein a material of the third layer completely surrounds at least one conductor wire of the one or more conductor wires.

[0230] Various examples of the disclosure have been described. Any combination of the described systems, operations, or functions is contemplated. These and other examples are within the scope of the following claims.

Claims

Docket No.: A0012639W001 / 1241-321W001WHAT IS CLAIMED IS:

1. A medical device comprising: an elongated body configured to be introduced into a blood vessel of a patient; and an expandable structure at a distal portion of the elongated body, the expandable structure including: a first layer having a first Shore D hardness; a second layer having a second Shore D hardness and positioned radially outward of the first layer, the second Shore D hardness greater than the first Shore D hardness; and a third layer having a third Shore D hardness and positioned radially outward of the first layer and the second layer, the third Shore D hardness less than or equal to the first Shore D hardness and less than the second Shore D hardness, wherein: the third layer is configured to receive a stent such that the stent is at least partially embedded in the third layer, and / or the third layer is configured to receive one or more sensors such that the one or more sensors are at least partially embedded in the third layer.

2. The medical device of claim 1, wherein the second layer is directly adjacent to the first layer and the third layer is directly adjacent to the second layer.

3. The medical device of any of claims 1 and 2, wherein the second Shore D hardness is greater than or equal to 70D.

4. The medical device of any of claims 1 through 3, wherein the first Shore D hardness is 60D to 70D.

5. The medical device of any of claims 1 through 4, wherein the expandable structure defines a double wall thickness (DWT) of less or equal to than 0.0015 inches.

6. The medical device of any of claims 1 through 5, wherein the second layer is thicker than the first layer.

7. The medical device of any of claims 1 through 6, wherein the first layer includes a first material and the second layer includes a second material different than the first material.Docket No.: A0012639W001 / 1241-321W0018. The medical device of claim 7, wherein the third layer includes a third material different than the second material.

9. The medical device of claim 8, wherein the third material and the first material are the same.

10. The medical device of claim 8, wherein the third material and the first material are different.

11. The medical device of any of claims 1 through 10, wherein the one or more sensors include a pressure sensor or a force sensor.

12. The medical device of any of claims 1 through 11, wherein the third layer defines a pocket configured to receive the one or more sensors.

13. The medical device of any of claims 1 through 12, further comprising the one or more sensors and one or more conductor wires electrically coupled to the one or more sensors.

14. The medical device of claim 13, wherein the third layer defines a channel configured to receive at least one conductor wire of the one or more conductor wires.

15. The medical device of any of claims 13 and 14, wherein a material of the third layer completely surrounds at least one conductor wire of the one or more conductor wires.

Images