Patent Application
20230414177
The present disclosure generally relates to the field of medical implant devices.
Various medical procedures involve the implantation of a medical implant devices within the anatomy of the heart. Certain physiological parameters associated with such anatomy, such as fluid pressure, can have an impact on patient health prospects.
Described herein are one or more methods and/or devices to facilitate monitoring of physiological parameter(s) associated with certain chambers and/or vessels of the heart, such as the left atrium, using one or more sensor implant devices.
In some implementations, the present disclosure relates to a sensor implant device comprising a shunt body that forms a fluid conduit, a first anchor structure associated with a first axial end of the shunt body, and a first sensor-retention structure associated with a second axial end of the shunt body, the first sensor-retention structure being configured to hold a first sensor device in a sensing position in which a sensor transducer of the first sensor device is disposed at least partially radially outside of a channel area of the fluid conduit.
When in the sensing position, the first sensor device can be aligned with an axis of the fluid conduit.
In some embodiments, the first sensor-retention structure comprises a coil form configured to wrap around the first sensor device. For example, the coil form can be coaxial with the shunt body.
The first anchor structure can comprise a second a second sensor-retention structure configured to hold a second sensor device such that a sensor transducer of the second sensor device is disposed at least partially radially outside of the channel area of the fluid conduit. For example, the first sensor device and the second sensor device can be axially aligned with the shunt body. In some embodiments, the first sensor-retention structure is associated with a first portion of a circumference of the shunt body and the second sensor-retention structure is associated with a second portion of the circumference of the shunt body that is diametrically opposite the first portion. In some embodiments, the sensor transducer of the first sensor device and the sensor transducer of the second sensor device face in opposite directions.
The sensor implant device can be configured to be compressed into a compressed state in which the first sensor-retention structure is disposed within the channel area of the fluid conduit.
In some embodiments, the first anchor structure has a diameter that is greater than a diameter of the shunt body.
In some embodiments, the shunt body is formed of a first plurality of winds of coil and the first sensor-retention structure is formed of a second plurality of winds of coil wrapped around the first sensor device. For example, the first plurality of winds of coil and the second plurality of winds of coil can be part of a common wireform. The first anchor structure can comprise a spiraled arm that is an integrated form with first plurality of winds of coil of the shunt body. In some embodiments, the shunt body further comprises a cover disposed outside at least a portion of the first plurality of winds of coil. The shunt body can further comprise a cover disposed within at least a portion of the first plurality of winds of coil.
In some implementations, the present disclosure relates to a sensor implant device comprising a coil wireform. The coil wireform comprises, in a deployed configuration, a barrel portion formed of a first plurality of winds of coil of the coil wireform and a first sensor-support structure emanating from a first axial end of the barrel portion, the first sensor-support structure including a sensor-retention means holding a first sensor device outside of a channel area of the barrel portion.
The sensor implant device can further comprise a second sensor-support structure emanating from a second axial end of the barrel portion, the second sensor-support structure holding a second sensor device outside of the channel area of the barrel portion.
In some embodiments, the sensor-retention means comprises one or more winds of coil.
In some embodiments, the sensor-retention means comprises a mechanical clip.
The sensor implant device can further comprise a sealing means associated with the barrel portion. For example, the sealing means can comprise a fabric layer.
In some embodiments, the coil wireform comprises shape memory material configured to assume the deployed configuration when deployed from a delivery catheter. For example, the coil wireform can be configured to be compressed into a delivery configuration in which the first plurality of winds of coil have a diameter that is smaller than a diameter of the first plurality of winds of coil in the deployed configuration.
For purposes of summarizing the disclosure, certain aspects, advantages, and novel features have been described. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, the disclosed embodiments may be carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
Various embodiments are depicted in the accompanying drawings for illustrative purposes and should in no way be interpreted as limiting the scope of the inventions. In addition, various features of different disclosed embodiments can be combined to form additional embodiments, which are pail of this disclosure. Throughout the drawings, reference numbers may be reused to indicate correspondence between reference elements.
The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.
Although certain preferred embodiments and examples are disclosed below, inventive subject matter extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses and to modifications and equivalents thereof. Thus, the scope of the claims that may arise herefrom is not limited by any of the particular embodiments described below. For example, in any method or process disclosed herein, the acts or operations of the method or process may be performed in any suitable sequence and are not necessarily limited to any particular disclosed sequence. Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding certain embodiments; however, the order of description should not be construed to imply that these operations are order dependent. Additionally, the structures, systems, and/or devices described herein may be embodied as integrated components or as separate components. For purposes of comparing various embodiments, certain aspects and advantages of these embodiments are described. Not necessarily all such aspects or advantages are achieved by any particular embodiment. Thus, for example, various embodiments may be carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other aspects or advantages as may also be taught or suggested herein.
Certain reference numbers are re-used across different figures of the figure set of the present disclosure as a matter of convenience for devices, components, systems, features, and/or modules having features that may be similar in one or more respects. However, with respect to any of the embodiments disclosed herein, re-use of common reference numbers in the drawings does not necessarily indicate that such features, devices, components, or modules are identical or similar. Rather, one having ordinary skill in the art may be informed by context with respect to the degree to which usage of common reference numbers can imply similarity between referenced subject matter. Use of a particular reference number in the context of the description of a particular figure can be understood to relate to the identified device, component, aspect, feature, module, or system in that particular figure, and not necessarily to any devices, components, aspects, features, modules, or systems identified by the same reference number in another figure. Furthermore, aspects of separate figures identified with common reference numbers can be interpreted to share characteristics or to be entirely independent of one another.
Certain standard anatomical terms of location are used herein to refer to the anatomy of animals, and namely humans, with respect to the preferred embodiments. Although certain spatially relative terms, such as “outer,” “inner,” “upper,” “lower,” “below,” “above,” “vertical,” “horizontal,” “top,” “bottom,” and similar terms, are used herein to describe a spatial relationship of one device/element or anatomical structure to another device/element or anatomical structure, it is understood that these terms are used herein for ease of description to describe the positional relationship between element(s)/structures(s), as illustrated in the drawings. It should be understood that spatially relative terms are intended to encompass different orientations of the element(s)/structures(s), in use or operation, in addition to the orientations depicted in the drawings. For example, an element/structure described as “above” another element/structure may represent a position that is below or beside such other element/structure with respect to alternate orientations of the subject patient or element/structure, and vice-versa.
The present disclosure relates to systems, devices, and methods for monitoring of one or more physiological parameters of a patient (e.g., blood pressure) using sensor-integrated cardiac shunts and/or other medical implant devices. In some implementations, the present disclosure relates to cardiac shunts and/or other cardiac implant devices that incorporate or are associated with pressure sensors or other sensor devices. The term “associated with” is used herein according to its broad and ordinary meaning. For example, where a first feature, element, component, device, or member is described as being “associated with” a second feature, element, component, device, or member, such description should be understood as indicating that the first feature, element, component, device, or member is physically coupled, attached, or connected to, integrated with, embedded at least partially within, or otherwise physically related to the second feature, element, component, device, or member, whether directly or indirectly. Certain embodiments are disclosed herein in the context of cardiac implant devices. However, although certain principles disclosed herein are particularly applicable to the anatomy of the heart, it should be understood that sensor implant devices in accordance with the present disclosure may be implanted in, or configured for implantation in, any suitable or desirable anatomy.
The anatomy of the heart is described below to assist in the understanding of certain inventive concepts disclosed herein. In humans and other vertebrate animals, the heart generally comprises a muscular organ having four pumping chambers, wherein the flow thereof is at least partially controlled by various heart valves, namely, the aortic, mitral (or bicuspid), tricuspid, and pulmonary valves. The valves may be configured to open and close in response to a pressure gradient present during various stages of the cardiac cycle (e.g., relaxation and contraction) to at least partially control the flow of blood to a respective region of the heart and/or to blood vessels (e.g., pulmonary, aorta, etc.).
In addition to the pulmonary valve 9, the heart 1 includes three additional valves for aiding the circulation of blood therein, including the tricuspid valve 8, the aortic valve 7, and the mitral valve 6. The tricuspid valve 8 separates the right atrium 5 from the right ventricle 4. The tricuspid valve 8 generally has three cusps or leaflets and may generally close during ventricular contraction (i.e., systole) and open during ventricular expansion (i.e., diastole). The mitral valve 6 generally has two cusps/leaflets and separates the left atrium 2 from the left ventricle 3. The mitral valve 6 is configured to open during diastole so that blood in the left atrium 2 can flow into the left ventricle 3, and, when functioning properly, closes during systole to prevent blood from leaking back into the left atrium 2. The aortic valve 7 separates the left ventricle 3 from the aorta 12. The aortic valve 7 is configured to open during systole to allow blood leaving the left ventricle 3 to enter the aorta 12, and close during diastole to prevent blood from leaking back into the left ventricle 3.
The heart valves may generally comprise a relatively dense fibrous ring, referred to herein as the annulus, as well as a plurality of leaflets or cusps attached to the annulus. Generally, the size of the leaflets or cusps may be such that when the heart contracts the resulting increased blood pressure produced within the corresponding heart chamber forces the leaflets at least partially open to allow flow from the heart chamber. As the pressure in the heart chamber subsides, the pressure in the subsequent chamber or blood vessel may become dominant and press back against the leaflets. As a result, the leaflets/cusps come in apposition to each other, thereby closing the flow passage. Disfunction of a heart valve and/or associated leaflets (e.g., pulmonary valve disfunction) can result in valve leakage and/or other health complications.
The atrioventricular (i.e., mitral and tricuspid) heart valves may further comprise a collection of chordae tendineae and papillary muscles (not shown) for securing the leaflets of the respective valves to promote and/or facilitate proper coaptation of the valve leaflets and prevent prolapse thereof. The papillary muscles, for example, may generally comprise finger-like projections from the ventricle wall. The valve leaflets are connected to the papillary muscles by the chordae tendineae. A wall of muscle, referred to as the septum, separates the left-side chambers from the right-side chambers. In particular, an atrial septum wall portion 18 (referred to herein as the “atrial septum,” “atrial septum,” or “septum”) separates the left atrium 2 from the right atrium 5, whereas a ventricular septum wall portion 17 (referred to herein as the “ventricular septum,” “interventricular septum,” or “septum”) separates the left ventricle 3 from the right ventricle 4. The inferior tip 14 of the heart 1 is referred to as the apex and is generally located on or near the midclavicular line, in the fifth intercostal space.
The coronary sinus 16 comprises a collection of veins joined together to form a relatively large vessel that collects blood from the heart muscle (myocardium). The ostium of the coronary sinus 16, which can be guarded at least in part by a Thebesian valve in some patients, is open to the right atrium 5, as shown. The coronary sinus runs along a posterior aspect of the left atrium 2 and delivers less-oxygenated blood to the right atrium 5. The coronary sinus generally runs transversely in the left atrioventricular groove on the posterior side of the heart.
Health Conditions Associated with Cardiac Pressure and Other Parameters
As referenced above, certain physiological conditions or parameters associated with the cardiac anatomy can impact the health of a patient. For example, congestive heart failure is a condition associated with the relatively slow movement of blood through the heart and/or body, which causes the fluid pressure in one or more chambers of the heart to increase. As a result, the heart does not pump sufficient oxygen to meet the body's needs. The various chambers of the heart may respond to pressure increases by stretching to hold more blood to pump through the body or by becoming relatively stiff and/or thickened. The walls of the heart can eventually weaken and become unable to pump as efficiently. In some cases, the kidneys may respond to cardiac inefficiency by causing the body to retain fluid. Fluid build-up in arms, legs, ankles, feet, lungs, and/or other organs can cause the body to become congested, which is referred to as congestive heart failure. Acute decompensated congestive heart failure is a leading cause of morbidity and mortality, and therefore treatment and/or prevention of congestive heart failure is a significant concern in medical care.
The treatment and/or prevention of heart failure (e.g., congestive heart failure) can advantageously involve the monitoring of pressure in one or more chambers or regions of the heart or other anatomy. As described above, pressure buildup in one or more chambers or areas of the heart can be associated with congestive heart failure. Without direct or indirect monitoring of cardiac pressure, it can be difficult to infer, determine, or predict the presence or occurrence of congestive heart failure. For example, treatments or approaches not involving direct or indirect pressure monitoring may involve measuring or observing other present physiological conditions of the patient, such as measuring body weight, thoracic impedance, right heart catheterization, or the like. In some solutions, pulmonary capillary wedge pressure can be measured as a surrogate of left atrial pressure. For example, a pressure sensor may be disposed or implanted in the pulmonary artery, and readings associated therewith may be used as a surrogate for left atrial pressure. However, with respect to catheter-based pressure measurement in the pulmonary artery or certain other chambers or regions of the heart, use of invasive catheters may be required to maintain such pressure sensors, which may be uncomfortable or difficult to implement. Furthermore, certain lung-related conditions may affect pressure readings in the pulmonary artery, such that the correlation between pulmonary artery pressure and left atrial pressure may be undesirably attenuated. As an alternative to pulmonary artery pressure measurement, pressure measurements in the right ventricle outflow tract may relate to left atrial pressure as well. However, the correlation between such pressure readings and left atrial pressure may not be sufficiently strong to be utilized in congestive heart failure diagnostics, prevention, and/or treatment.
Additional solutions may be implemented for deriving or inferring left atrial pressure. For example, the E/A ratio, which is a marker of the function of the left ventricle of the heart representing the ratio of peak velocity blood flow from gravity in early diastole (the E wave) to peak velocity flow in late diastole caused by atrial contraction (the A wave), can be used as a surrogate for measuring left atrial pressure. The E/A ratio may be determined using echocardiography or other imaging technology; generally, abnormalities in the E/A ratio may suggest that the left ventricle cannot fill with blood properly in the period between contractions, which may lead to symptoms of heart failure, as explained above. However, E/A ratio determination generally does not provide absolute pressure measurement values.
Various methods for identifying and/or treating congestive heart failure involve the observation of worsening congestive heart failure symptoms and/or changes in body weight. However, such signs may appear relatively late and/or be relatively unreliable. For example, daily bodyweight measurements may vary significantly (e.g., up to 9% or more) and may be unreliable in signaling heart-related complications. Furthermore, treatments guided by monitoring signs, symptoms, weight, and/or other biomarkers have not been shown to substantially improve clinical outcomes. In addition, for patients that have been discharged, such treatments may necessitate remote telemedicine systems.
The present disclosure provides systems, devices, and methods for guiding the administration of medication relating to the treatment of congestive heart failure at least in part by directly monitoring pressure in the left atrium, or other chamber or vessel for which pressure measurements are indicative of left atrial pressure and/or pressure levels in one or more other vessels/chambers, such as for congestive heart failure patients in order to reduce hospital readmissions, morbidity, and/or otherwise improve the health prospects of the patient.
Cardiac pressure monitoring in accordance with embodiments of the present disclosure may provide a proactive intervention mechanism for preventing or treating congestive heart failure and/or other physiological conditions. Generally, increases in ventricular filling pressures associated with diastolic and/or systolic heart failure can occur prior to the occurrence of symptoms that lead to hospitalization. For example, cardiac pressure indicators may present weeks prior to hospitalization with respect to some patients. Therefore, pressure monitoring systems in accordance with embodiments of the present disclosure may advantageously be implemented to reduce instances of hospitalization by guiding the appropriate or desired titration and/or administration of medications before the onset of heart failure.
Dyspnea represents a cardiac pressure indicator characterized by shortness of breath or the feeling that one cannot breathe sufficiently. Dyspnea may result from elevated atrial pressure, which may cause fluid buildup in the lungs from pressure back-up. Pathological dyspnea can result from congestive heart failure. However, a significant amount of time may elapse between the time of initial pressure elevation and the onset of dyspnea, and therefore symptoms of dyspnea may not provide sufficiently-early signaling of elevated atrial pressure. By monitoring pressure directly according to embodiments of the present disclosure, normal ventricular filling pressures may advantageously be maintained, thereby preventing or reducing effects of heart failure, such as dyspnea.
As referenced above, with respect to cardiac pressures, pressure elevation in the left atrium may be particularly correlated with heart failure.
Left atrial pressure may generally correlate well with left ventricular end-diastolic pressure. However, although left atrial pressure and end-diastolic pulmonary artery pressure can have a significant correlation, such correlation may be weakened when the pulmonary vascular resistance becomes elevated. That is, pulmonary artery pressure generally fails to correlate adequately with left ventricular end-diastolic pressure in the presence of a variety of acute conditions, which may include certain patients with congestive heart failure. For example, pulmonary hypertension, which affects approximately 25% to 83% of patients with heart failure, can affect the reliability of pulmonary artery pressure measurement for estimating left-sided filling pressure. Therefore, pulmonary artery pressure measurement alone, as represented by the waveform 124, may be an insufficient or inaccurate indicator of left ventricular end-diastolic pressure, particularly for patients with comorbidities, such as lung disease and/or thromboembolism. Left atrial pressure may further be correlated at least partially with the presence and/or degree of mitral regurgitation.
Left atrial pressure readings may be relatively less likely to be distorted or affected by other conditions, such as respiratory conditions or the like, compared to the other pressure waveforms shown in
Cardiac pressure monitoring, such as left atrial pressure monitoring, can provide a mechanism to guide administration of medication to treat and/or prevent congestive heart failure. Such treatments may advantageously reduce hospital readmissions and morbidity, as well as provide other benefits. An implanted pressure sensor in accordance with embodiments of the present disclosure may be used to predict heart failure up two weeks or more before the manifestation of symptoms or markers of heart failure (e.g., dyspnea). When heart failure predictors are recognized using cardiac pressure sensor embodiments in accordance with the present disclosure, certain prophylactic measures may be implemented, including medication intervention, such as modification to a patient's medication regimen, which may help prevent or reduce the effects of cardiac dysfunction. Direct pressure measurement in the left atrium can advantageously provide an accurate indicator of pressure buildup that may lead to heart failure or other complications. For example, trends of atrial pressure elevation may be analyzed or used to determine or predict the onset of cardiac dysfunction, wherein drug or other therapy may be augmented to cause reduction in pressure and prevent or reduce further complications.
In some implementations, the present disclosure relates to sensors associated or integrated with cardiac shunts or other implant devices. Such integrated devices may be used to provide controlled and/or more effective therapies for treating and preventing heart failure and/or other health complications related to cardiac function.
The control circuitry 34 may be configured to process signals received from the transducer 32 and/or communicate signals associated therewith wirelessly through biological tissue using the antenna 38. The term “control circuitry” is used herein according to its broad and ordinary meaning, and may refer to any collection of processors, processing circuitry, processing modules/units, chips, dies (e.g., semiconductor dies including come or more active and/or passive devices and/or connectivity circuitry), microprocessors, microcontrollers, digital signal processors, microcomputers, central processing units, field programmable gate arrays, programmable logic devices, state machines (e.g., hardware state machines), logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on hard coding of the circuitry and/or operational instructions. Control circuitry referenced herein may further comprise one or more, storage devices, which may be embodied in a single memory device, a plurality of memory devices, and/or embedded circuitry of a device. Such data storage may comprise read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, data storage registers, and/or any device that stores digital information. It should be noted that in embodiments in which control circuitry comprises a hardware and/or software state machine, analog circuitry, digital circuitry, and/or logic circuitry, data storage device(s)/register(s) storing any associated operational instructions may be embedded within, or external to, the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry. The transducer(s) 32 and/or antenna(s) 38 can be considered part of the control circuitry 34.
The antenna 38 may comprise one or more coils or loops of conductive material, such as copper wire or the like. In some embodiments, at least a portion of the transducer 32, control circuitry 34, and/or the antenna 38 are at least partially disposed or contained within a sensor housing 36, which may comprise any type of material, and may advantageously be at least partially hermetically sealed. For example, the housing 36 may comprise glass or other rigid material in some embodiments, which may provide mechanical stability and/or protection for the components housed therein. In some embodiments, the housing 36 is at least partially flexible. For example, the housing may comprise polymer or other flexible structure/material, which may advantageously allow for folding, bending, or collapsing of the sensor 37 to allow for transportation thereof through a catheter or other introducing means.
The transducer 32 may comprise any type of sensor means or mechanism. For example, the transducer 32 may be a force-collector-type pressure sensor. In some embodiments, the transducer 32 comprises a diaphragm, piston, bourdon tube, bellows, or other strain- or deflection-measuring component(s) to measure strain or deflection applied over an area/surface thereof. The transducer 32 may be associated with the housing 36, such that at least a portion thereof is contained within or attached to the housing 36. With respect to sensor devices/components being “associated with” a stent or other implant structure, such terminology may refer to a sensor device or component being physically coupled, attached, or connected to, or integrated with, the implant structure.
In some embodiments, the transducer 32 comprises or is a component of a piezoresistive strain gauge, which may be configured to use a bonded or formed strain gauge to detect strain due to applied pressure, wherein resistance increases as pressure deforms the component/material. The transducer 32 may incorporate any type of material, including but not limited to silicon (e.g., monocrystalline), polysilicon thin film, bonded metal foil, thick film, silicon-on-sapphire, sputtered thin film, and/or the like.
In some embodiments, the transducer 32 comprises or is a component of a capacitive pressure sensor including a diaphragm and pressure cavity configured to form a variable capacitor to detect strain due to pressure applied to the diaphragm. The capacitance of the capacitive pressure sensor may generally decrease as pressure deforms the diaphragm. The diaphragm may comprise any material(s), including but not limited to metal, ceramic, silicon, and the like. In some embodiments, the transducer 32 comprises or is a component of an electromagnetic pressure sensor, which may be configured to measure the displacement of a diaphragm by means of changes in inductance, linear variable displacement transducer (LVDT) functionality, Hall Effect, or eddy current sensing. In some embodiments, the transducer 32 comprises or is a component of a piezoelectric strain sensor. For example, such a sensor may determine strain (e.g., pressure) on a sensing mechanism based on the piezoelectric effect in certain materials, such as quartz.
In some embodiments, the transducer 32 comprises or is a component of a strain gauge. For example, a strain gauge embodiment may comprise a pressure sensitive element on or associated with an exposed surface of the transducer 32. In some embodiments, a metal strain gauge is adhered to a surface of the sensor, or a thin-film gauge may be applied on the sensor by sputtering or other technique. The measuring element or mechanism may comprise a diaphragm or metal foil. The transducer 32 may comprise any other type of sensor or pressure sensor, such as optical, potentiometric, resonant, thermal, ionization, or other types of strain or pressure sensors.
In certain embodiments, the monitoring system 40 can comprise at least two subsystems, including an implantable internal subsystem or device 30 that includes the sensor transducer(s) 32, as well as control circuitry 34 comprising one or more microcontroller(s), discrete electronic component(s), and one or more power and/or data transmitter(s) 38 (e.g., antennae coil). The monitoring system 40 can further include an external (e.g., non-implantable) subsystem that includes an external reader 42 (e.g., coil), which may include a wireless transceiver that is electrically and/or communicatively coupled to certain control circuitry 41. In certain embodiments, both the internal 30 and external 42 subsystems include a corresponding coil antenna for wireless communication and/or power delivery through patient tissue disposed therebetween. The sensor implant device 30 can be any type of implant device. For example, in some embodiments, the implant device 30 comprises a pressure sensor integrated with another functional implant structure 39, such as a prosthetic shunt or stent device/structure.
Certain details of the implant device 30 are illustrated in the enlarged block 30 shown. The implant device 30 can comprise an implant/anchor structure 39 as described herein. For example, the implant/anchor structure 39 can include a percutaneously-deliverable shunt device configured to be secured to and/or in a tissue wall to provide a flow path between two chambers and/or vessels of the heart, as described in detail throughout the present disclosure. The implant/anchor structure 39 can comprise a helical/coiled wireform in some embodiments, as disclosed in detail herein.
Although certain components are illustrated in
The sensor transducer(s) 32 can comprise one or more MEMS sensors, optical sensors, piezoelectric sensors, electromagnetic sensors, strain sensors/gauges, accelerometers, gyroscopes, diaphragm-based sensors, and/or other types of sensors, which can be positioned in the patient 44 to sense one or more parameters relevant to the health of the patient. The transducer 32 may be a force-collector-type pressure sensor. In some embodiments, the transducer 32 comprises a diaphragm, piston, bourdon tube, bellows, or other strain- or deflection-measuring component(s) to measure strain or deflection applied over an area/surface thereof. The transducer 32 may be associated with the sensor housing 36, such that at least a portion thereof is contained within, or attached to, the housing 36.
In some embodiments, the transducer 32 comprises or is a component of a strain gauge, which may be configured to use a bonded or formed strain gauge to detect strain due to applied pressure. For example, the transducer 32 may comprise or be a component of a piezoresistive strain gauge, wherein resistance increases as pressure deforms the component/material of the strain gauge. The transducer 32 may incorporate any type of material, including but not limited to silicone, polymer, silicon (e.g., monocrystalline), polysilicon thin film, bonded metal foil, thick film, silicon-on-sapphire, sputtered thin film, and/or the like. In some embodiments, a metal strain gauge is adhered to the sensor surface, or a thin-film gauge may be applied on the sensor by sputtering or other technique. The measuring element or mechanism may comprise a diaphragm or metal foil. The transducer 32 may comprise any other type of sensor or pressure sensor, such as optical, potentiometric, resonant, thermal, ionization, or other types of strain or pressure sensors.
In some embodiments, the transducer 32 comprises or is a component of a capacitive pressure sensor including a diaphragm and pressure cavity configured to form a variable capacitor to detect strain due to pressure applied to the diaphragm. The capacitance of the capacitive pressure sensor may generally decrease as pressure deforms the diaphragm. The diaphragm may comprise any material(s), including but not limited to metal, ceramic, silicone, silicon or other semiconductor, and the like. In some embodiments, the transducer 32 comprises or is a component of an electromagnetic pressure sensor, which may be configured to measures the displacement of a diaphragm by means of changes in inductance, linear variable displacement transducer (LV DT) functionality, Hall Effect, or eddy current sensing. In some embodiments, the transducer 32 comprises or is a component of a piezoelectric strain sensor. For example, such a sensor may determine strain (e.g., pressure) on a sensing mechanism based on the piezoelectric effect in certain materials, such as quartz.
In some embodiments, the transducer(s) 32 is/are electrically and/or communicatively coupled to the control circuitry 34, which may comprise one or more application-specific integrated circuit (ASIC) microcontrollers or chips. The control circuitry 34 can further include one or more discrete electronic components, such as tuning capacitors, resistors, diodes, inductors, or the like.
In certain embodiments, the sensor transducer(s) 32 can be configured to generate electrical signals that can be wirelessly transmitted to a device outside the patient's body, such as the illustrated local external monitor system 42. In order to perform such wireless data transmission, the implant device 30 can include radio frequency (RF) (or other frequency band) transmission circuitry, such as signal processing circuitry and an antenna 38. The antenna 38 can comprise an antenna coil implanted within the patient. The control circuitry 34 may comprise any type of transceiver circuitry configured to transmit an electromagnetic signal, wherein the signal can be radiated by the antenna 38, which may comprise one or more conductive wires, coils, plates, or the like. The control circuitry 34 of the implant device 30 can comprise, for example, one or more chips or dies configured to perform some amount of processing on signals generated and/or transmitted using the device 30. However, due to size, cost, and/or other constraints, the implant device 30 may not include independent processing capability in some embodiments.
The wireless signals generated by the implant device 30 can be received by the local external monitor device or subsystem 42, which can include a reader/antenna-interface circuitry module 43 configured to receive the wireless signal transmissions from the implant device 30, which is disposed at least partially within the patient 44. For example, the module 43 may include transceiver device(s)/circuitry.
The external local monitor 42 can receive the wireless signal transmissions from the implant device 30 and/or provide wireless power to the implant device 30 using an external antenna 48, such as a wand device. The reader/antenna-interface circuitry 43 can include radio-frequency (RF) (or other frequency band) front-end circuitry configured to receive and amplify the signals from the implant device 30, wherein such circuitry can include one or more filters (e.g., band-pass filters), amplifiers (e.g., low-noise amplifiers), analog-to-digital converters (ADC) and/or digital control interface circuitry, phase-locked loop (PLL) circuitry, signal mixers, or the like. The reader/antenna-interface circuitry 43 can further be configured to transmit signals over a network 49 to a remote monitor subsystem or device 46. The RF circuitry of the reader/antenna-interface circuitry 43 can further include one or more of digital-to-analog converter (DAC) circuitry, power amplifiers, low-pass filters, antenna switch modules, antennas or the like for treatment/processing of transmitted signals over the network 49 and/or for receiving signals from the implant device 30. In certain embodiments, the local monitor 42 includes control circuitry 41 for performing processing of the signals received from the implant device 30. The local monitor 42 can be configured to communicate with the network 49 according to a known network protocol, such as Ethernet, Wi-Fi, or the like. In certain embodiments, the local monitor 42 comprises a smartphone, laptop computer, or other mobile computing device, or any other type of computing device.
In certain embodiments, the implant device 30 includes some amount of volatile and/or non-volatile data storage. For example, such data storage can comprise solid-state memory utilizing an array of floating-gate transistors, or the like. The control circuitry 34 may utilize data storage for storing sensed data collected over a period of time, wherein the stored data can be transmitted periodically to the local monitor 42 or another external subsystem. In certain embodiments, the implant device 30 does not include any data storage. The control circuitry 34 may be configured to facilitate wireless transmission of data generated by the sensor transducer(s) 32, or other data associated therewith. The control circuitry 34 may further be configured to receive input from one or more external subsystems, such as from the local monitor 42, or from a remote monitor 46 over, for example, the network 49. For example, the implant device 30 may be configured to receive signals that at least partially control the operation of the implant device 30, such as by activating/deactivating one or more components or sensors, or otherwise affecting operation or performance of the implant device 30.
The one or more components of the implant device 30 can be powered by one or more power sources 35. Due to size, cost and/or electrical complexity concerns, it may be desirable for the power source 35 to be relatively minimalistic in nature. For example, high-power driving voltages and/or currents in the implant device 30 may adversely affect or interfere with operation of the heart or other body part associated with the implant device. In certain embodiments, the power source 35 is at least partially passive in nature, such that power can be received from an external source wirelessly by passive circuitry of the implant device 30, such as through the use of short-range, or near-field wireless power transmission, or other electromagnetic coupling mechanism. For example, the local monitor 42 may serve as an initiator that actively generates an RE field that can provide power to the implant device 30, thereby allowing the power circuitry of the implant device to take a relatively simple form factor. In certain embodiments, the power source 35 can be configured to harvest energy from environmental sources, such as fluid flow, motion, or the like. Additionally or alternatively, the power source 35 can comprise a battery, which can advantageously be configured to provide enough power as needed over the monitoring period (e.g., 3, 5, 10, 20, 30, 40, or 90 days, or other period of time).
In some embodiments, the local monitor device 42 can serve as an intermediate communication device between the implant device 30 and the remote monitor 46. The local monitor device 42 can be a dedicated external unit designed to communicate with the implant device 30. For example, the local monitor device 42 can be a wearable communication device, or other device that can be readily disposed in proximity to the patient 44 and implant device 30. The local monitor device 42 can be configured to continuously, periodically, or sporadically interrogate the implant device 30 in order to extract or request sensor-based information therefrom. In certain embodiments, the local monitor 42 comprises a user interface, wherein a user can utilize the interface to view sensor data, request sensor data, or otherwise interact with the local monitor system 42 and/or implant device 30.
The system 40 can include a secondary local monitor 47, which can be, for example, a desktop computer or other computing device configured to provide a monitoring station or interface for viewing and/or interacting with the monitored cardiac pressure data. In an embodiment, the local monitor 42 can be a wearable device or other device or system configured to be disposed in close physical proximity to the patient and/or implant device 30, wherein the local monitor 42 is primarily designed to receive/transmit signals to and/or from the implant device 30 and provide such signals to the secondary local monitor 47 for viewing, processing, and/or manipulation thereof. The external local monitor system 42 can be configured to receive and/or process certain metadata from or associated with the implant device 30, such as device ID or the like, which can also be provided over the data coupling from the implant device 30.
The remote monitor subsystem 46 can be any type of computing device or collection of computing devices configured to receive, process and/or present monitor data received over the network 49 from the local monitor device 42, secondary local monitor 47, and/or implant device 30. For example, the remote monitor subsystem 46 can advantageously be operated and/or controlled by a healthcare entity, such as a hospital, doctor, or other care entity associated with the patient 44. Although certain embodiments disclosed herein describe communication with the remote monitor subsystem 46 from the implant device indirectly through the local monitor device 42, in certain embodiments, the implant device 30 can comprise a transmitter capable of communicating over the network 49 with the remote monitor subsystem 46 without the necessity of relaying information through the local monitor device 42.
In some embodiments, at least a portion of the transducer 32, control circuitry 34, power source 35 and/or the antenna 38 are at least partially disposed or contained within the sensor housing 36, which may comprise any type of material, and may advantageously be at least partially hermetically sealed. For example, the housing 36 may comprise glass or other rigid material in some embodiments, which may provide mechanical stability and/or protection for the components housed therein. In some embodiments, the housing 36 is at least partially flexible. For example, the housing may comprise polymer or other flexible structure/material, which may advantageously allow for folding, bending, or collapsing of the sensor 30 to allow for transportation thereof through a catheter or other percutaneous introducing means.
As referenced above, shunt and other implant devices/structures may be integrated with sensor, antenna/transceiver, and/or other components to facilitate in vivo monitoring of pressure and/or other physiological parameter(s). Sensor devices in accordance with embodiments of the present disclosure may be integrated with cardiac shunt structures/devices or other implant devices using any suitable or desirable attachment or integration mechanism or configuration.
The sensor implant device 70 comprises a shunt structure 90, which may comprise a coil wireform including one or more wires or other material or structure shaped into one or more winds of coil forming a fluid conduit/barrel portion 98 and one or more axial end flanges 95. Although described as flanges herein, it should be understood that such features may be any type of anchor structures configured to secure a shunt structure/body in a position in a tissue wall. The shunt structure 90 may represent an embodiment of a cardiac implant (e.g., anchor and/or cardiac implant structure 39 associated with
The sensor device 60 may be associated with either axial side/end of the shunt structure 90, wherein the different axial sides/ends 701, 702 of the shunt structure 90 are exposed on opposite sides (S1, S2) of a tissue wall when the implant device 70 is implanted in the tissue wall. As described herein, references to axial sides of a shunt structure may refer to opposite sides of a plane P1 axially (and/or diagonally) bisecting the shunt structure 90 and/or barrel portion 98 thereof. The plane P1 may be orthogonal or angled with respect to an axis of the barrel portion 98 of the shunt structure 90 and/or may be substantially parallel with (e.g. on/within) a tissue wall in which the shunt structure 90 is configured to be implanted. Description herein of axial sides of an implant structure can be understood to refer to different sides of the tissue-engagement plane P1 The plane P1 may be aligned (e.g., within 5° or 10° of exact alignment) with at least some of the coils/winds 91 of the barrel/conduit portion 98 of the shunt structure 90.
Furthermore, description herein of sensor devices and/or sensor arms being disposed on different radial sides of a shunt structure may refer to diametrically opposite sides of a diametrical plane P2, as shown in
The barrel portion 98 of the shunt structure 90 may advantageously be self-adjusting with respect to an axial length thereof. For example, the shape/form of the helical wire coil can allow for the barrel 98 to be axially expanded, thereby introducing gaps between adjacent winds 91 of the coil barrel 98. Therefore, the shunt structure 90 may be configured to be implanted in range of anatomies and or tissue walls having various characteristics and/or dimensions. In some embodiments, the barrel coil 98 is biased in an axially compacted configuration, as shown in
The sensor device 60 may advantageously be disposed, positioned, secured, oriented, and/or otherwise situated in a configuration in which the sensor transducer component 65 thereof is disposed outside of a channel area 88 of the shunt structure 90, such that the sensor 60 is radially offset with respect to the axis A1 of the barrel/body 98. By supporting/holding the sensor 60 outside of the channel area 88, the flow into and through the opening 96 into the barrel/body 98 of the device 70 may not be impeded in a manner that may occur in implementations in which a sensor device is held over the relevant channel area. That is, the channel area 88 may be associated with flow from the source chamber/vessel (e.g., left atrium; S1) into and through the shunt structure 90. Therefore, the presence of structure in the channel area, particularly in the area axially near the barrel 98 and/or opening 96, can interfere and/or block flow into the shunt. Embodiments of the present disclosure advantageously reduce/obviate such concerns/effects by placing/holding sensor devices at least partially (e.g., mostly) outside of the relevant channel area of the shunt structure, thereby providing a clear path from the source chamber/vessel into the shunt. The term “channel area” is used herein according to its broad and ordinary meaning and may refer to a three-dimensional space defined by a radial boundary of a fluid conduit and extending axially from the fluid conduit. For example, with respect to a given fluid conduit structure, such as the fluid conduit/barrel structure 98 of the shunt structure 90, a channel area 88 associated therewith may be considered to be defined according to any of the illustrated and described channel areas shown in
The shunt structure 90 may be a radially expandable shunt. When expanded, a central flow channel 96 of the shunt 90 may define a generally circular or oval opening. The channel 96 may be configured to hold the sides of a puncture opening in a tissue wall to form a blood flow path between chamber(s) or vessel(s) of the heart (or other anatomy) that are separated by the tissue wall. For example, the shunt structure 90 may be configured to be implanted in the wall separating the coronary sinus and the left atrium. The central flow channel 96 may be partly formed by one or more winds 91 of the coliform structure 90 that make up a body portion of the shunt structure 90. In some embodiments, substantially the entire shunt 90 is formed by super-elastic wire(s) (e.g., memory metal; nitinol) that is/are configured to be radially and/or otherwise compressed and fit into a catheter (not shown) and subsequently expanded back to the relaxed/deployed shape as shown in
The shunt structure/frame 90 may have a helical shape in one or more portions thereof, including one or more distal and/or proximal curved arms at one or both ends of the frame 90, which may form one or more anchor flanges (e.g., flange 95), at least in part. The shape of the barrel/body 98 and/or flange 95 portions of the shunt structure/frame 90 may be pre-shaped to assume the deployed form of
Formation of the shunt 90 using one or more elongate wires may serve to at least partially increase the flexibility of the shunt, thereby enabling compression thereof and expansion at the implant site. As mentioned above, the coil form shunt structure 90 may include a barrel/body portion 98 and one or more flange portions 95. For example, in some embodiments, the barrel portion 98 may include one or more winds 91 of coil having a diameter Di, wherein the wind(s) 91 define a barrel or fluid conduit structure 98 through which fluid may be shunted in accordance with aspects of the present disclosure. That is, the inside of the barrel/body 98 and/or coil winds 91 thereof can define a fluid pathway/conduit. In some embodiments, such conduit 98 is substantially fluid tight. For example, the winds 91 may be compressed tightly enough together in the deployed configuration shown in
The coil winds 91 forming the central flow channel 96 advantageously provide a tube having sufficient rigidity and structure to hold the tissue at the puncture site in an open position. The barrel portion 98 extends axially between the distal 701 and proximal 702 ends on each side, wherein one or more of the sides 701, 702 may be associated with flange anchor coil(s). For example, flange portion(s) (e.g., flange 95) of the coil form 90 can generally be associated with proximal 702 (as in
Although certain embodiments of shunt structures disclosed herein comprise flow channels having substantially circular cross-sections, in some embodiments, shunt structures in accordance with the present disclosure have oval-shaped, rectangular, diamond-shaped, or elliptical flow channel configurations. For example, the one or more coils/winds 91 or other structural features of the shunt structure 90 of
In some embodiments, the flange(s) 95 is/are configured to radiate outward in a spiral form from the perimeter 87 of the barrel 98. Such spiral flange coils/wires 95 can be shape-set to lie in a flange plane P1, in the expanded/deployed configuration shown in
The coil form shunt 90 further includes one or more sensor arms 92, which may emanate from one or more of the flange(s) 95 and/or from an axial end of the barrel/body portion 98 of the shunt structure 90. For example, where the shunt structure 90 comprises one or more coiled wires, such coil forms may have one or more wire ends, which may generally be associated with either or both of the proximal 702 and distal 701 ends and/or associated flange(s) of the shunt structure 90. One or more of such wire end portions may be implemented as a sensor arm configured to hold and retain a sensor device 60 for the purpose of facilitating physiological parameter monitoring/sensing in accordance with aspects of the present disclosure. With respect to the illustrated embodiment of
In some embodiments, the sensor arm 92 is deflected axially with respect to the tissue-engagement plane P1 of the shunt structure 90 and/or the plane Pj of the distal-most coil/end 701 from which the arm 92 emanates by an amount/angle θ1. Although
Deflection of the sensor 60 and sensor arm 92 distally from the end 701 (e.g., distal flange or other coil/wind) can be implemented to provide a flow path for fluid to be shunted under the base of the sensor 60 and/or through the fluid conduit 98 of the shunt structure 90.
The angle θ1 may be any desirable angle between the extension portion 75 of the sensor arm 92 and the tissue-engagement plane P1 and/or plane Pj of the end 701 (e.g., flange). In some embodiments, the deflection angle θ1 is between about 10-20° 20-30°, 30-45°, or other value. For example, the angle θ, may be about 10°, 15°, 20°, 25°, 30°, 35°, 40°, or 45°. For embodiments in which the arm 92 is deflected by an angle greater than 45°, such implementations may place at least a portion of the sensor device 60 inside the channel area 88. Therefore, it may be desirable to implement a sensor arm deflection angle θ1 that is less than 45° to maintain the sensor device 60 and/or transducer component 65 thereof outside of the channel area 88 of the shunt structure 90.
The sensor arm 92 may further include a sensor-retention portion 93, which may comprise one or more wraps/winds 99 of the coil arm 92 in a relatively tightly-wrapped configuration around the body/housing 69 of the sensor device 60 to thereby restrain/retain, at least in part, the sensor device 60 and hold the sensor device 60 in the desired sensing position. It may be desirable for the winds 99 of the coil in the retention portion 93 of the sensor arm 92 to be sufficiently tight and/or secured to reduce the risk of dislodgment/escape of the sensor device 60 in the presence of fluid flow and/or other fluid conditions (e.g., pressure) in the implantation environment. Although
As shown in
The sensor arm 92 may be deflected in a manner as to position the sensor device 60 and/or sensor transducer 65 wholly or partly outside of the channel area 88 and or perimeter 87 of the barrel 98. As shown in
The sensor-retention portion 93 and/or sensor arm 92 can be configured to hold the sensor in an orientation in which the sensor 60 is parallel or about parallel (e.g., within 5-10° of exact parallel alignment) with the axis A1 of the barrel 98 of the shunt structure 90. It should be understood that although
With reference to
The sensor transducer component 65 includes a sensor element 67, such as a pressure sensor transducer/membrane. As described herein, the sensor device 60 may be configured to implement wireless data and/or power transmission. The sensor device 60 may include the antenna component 61 for such purpose. The antenna 61, as well as one or more other components of the sensor device 60, may be contained at least partially within a sensor housing 69, which may further have disposed therein certain control circuitry 62 configured to facilitate wireless data and/or power communication functionality. In some embodiments, the antenna component 61 comprises one or more conductive coils/winds 67, which may facilitate inductive powering and/or data transmission. In embodiments comprising conductive coil(s), such coil(s) may be wrapped/disposed at least partially around a magnetic (e.g., ferrite, iron) core 79.
The sensor device 60 may advantageously be biocompatible. For example, the housing 69 may advantageously be biocompatible, such as a housing comprising glass or other biocompatible material. However, at least a portion of the sensor transducer element/membrane 67, such as a diaphragm or other component, may be exposed to the external environment in some embodiments in order to allow for pressure readings, or other parameter sensing, to be implemented. The housing 69 may comprise an at least partially rigid cylindrical or tube-like form, such as a glass cylinder form. In some embodiments, the sensor transducer component 65/67 is approximately 3 mm or less in diameter. The antenna 61 may be approximately 20 mm or less in length.
The sensor device 60 may be configured to communicate with an external system when implanted in a heart or other area of a patient's body. For example, the antenna 61 may receive power wirelessly from the external system and/or communicate sensed data or waveforms to and/or from the external system. The sensor element 67 may comprise a pressure transducer. For example, the pressure transducer may be a microelectromechanical system (MEMS) transducer comprising a semiconductor diaphragm component. In some embodiments, the transducer may include an at least partially flexible or compressible diaphragm component, which may be made from silicone or other flexible material. The diaphragm component may be configured to be flexed or compressed in response to changes in environmental pressure. The control circuitry 62 may be configured to process signals generated in response to said flexing/compression to provide pressure readings. In some embodiments, the diaphragm component is associated with a biocompatible layer on the outside surface thereof, such as silicon nitride (e.g., doped silicon nitride) or the like. The diaphragm component and/or other components of the pressure transducer 67 may advantageously be fused or otherwise sealed to/with the housing 69 of the sensor device 60 in order to provide hermetic sealing of at least some of the sensor components.
The control circuitry 62 may comprise one or more electronic application-specific integrated circuit (ASIC) chips or die, which may be programmed and/or customized or configured to perform monitoring functionality as described herein and/or facilitate transmission of sensor signals wirelessly. The antenna 61 may comprise a ferrite core 79 wrapped with conductive material in the form of a plurality of coils/winds 63 (e.g., wire coil). In some embodiments, the coils/winds comprise copper or other metal. The antenna 61 may advantageously be configured with coil geometry that does not result in substantial displacement or heating in the presence of magnetic resonance imaging. In some implementations, the sensor implant device 70 may be delivered to a target implant site using a delivery catheter (not shown), wherein the delivery catheter includes a cavity or channel configured to accommodate the advancement of the sensor device 60 therethrough.
The sensor arm 92 can hold the base 64 of the sensor in a manner as to at least partially radially overlap the barrel 98 beyond a distal axial end of the barrel 98. For example, the sensor arm 92 and/or base portion 75 thereof may be sufficiently short as to not extend the sensor 60 completely radially outside of the perimeter 87, while still positioning the sensor 60 at least partially radially outside of the channel area, which may advantageously produce a sensor implant device having a desirably small profile, length, and/or diameter with respect to at least the distal portion thereof. In some embodiments, the sensor arm 92 holds the sensor 60 in a manner such that the base 64 of the sensor 60 is axially below the top of the distal limit of the end 701 (i.e., end of the barrel 98 or distal-most coil from which the sensor arm 92 emanates (e.g., flange)) of the shunt structure 90. By holding the sensor against or near the barrel/body 98 of the shunt structure, the sensor arm 92 can be relatively stable compared to certain other embodiments in which the sensor arm extends a greater distance away from the barrel 98. In some embodiments, the sensor arm 92 is not radially deflected, and the sensor-retention portion 93 holds the sensor 60 in-line with and/or at least partially within the perimeter 87 of the barrel 98. In such embodiments, the sensor 60 can be held entirely or mostly within the channel area 88. That is, with respect to any of the embodiments disclosed herein, a sensor arm may hold the sensor near an axial end (e.g., distal end) of a barrel/body portion of the shunt structure, wherein the sensor is positioned at least partially within the channel area of the shunt structure. In some embodiments, the sensor arm 92 is inwardly radially deflected to position the sensor at least partially within the channel area. For example, the sensor arm 92 may be inwardly deflected to hold the sensor on or near the axis A1 of the barrel 98.
Although both proximal 195 and distal 194 flange portions are shown in
In some embodiments, each of the distal 194 and proximal 195 flanges/coils is configured to radiate outward in a spiral form from the perimeter of the barrel 198. Such spiral flange coils/wires 194, 195 can be shape-set to lie in a flange plane in the expanded/deployed configuration, which may be parallel with the tissue wall in the area of the implant device. The expanded flanges/coils 194, 195 may serve to secure the shunt structure 190 to the target tissue wall. Although certain embodiments are disclosed herein in the context of shunt structures similar to that shown in
As described above, some embodiments of the present disclosure include shunt structures having sensor arms configured to hold a sensor outside of a channel area of the shunt structure, which can advantageously facilitate unobstructed fluid flow through the shunt structure.
A sensor transducer disposed outside of the channel area 688 of the fluid conduit 698 shown in
As referenced, the sensor implant device 270 includes a seal or cover 250, which may comprise any suitable or desirable material and/or structure/form, such as cloth/fabric, polymer, mesh, or the like formed of any type of material. The cover 250 can be disposed over one or more portions or areas of the shunt structure 290. For example, as shown in
In some embodiments, the cover 250 is at least partially fluid-tight, such that the cover 250 serves to prevent or reduce fluid leakage outside of the implant device 270 when implanted. Furthermore, in some embodiments, the cover 250 may be configured to facilitate or promote tissue ingrowth between the implant device 270 and the surrounding tissue of the tissue wall in which the implant device 270 is implanted. Although illustrated as a covering/skirt-type structure, the cover 250 may be a coating or other application to the wireform shunt structure 290 (e.g., to the barrel 298) in some implementations. The cover 250 is advantageously biocompatible to allow for prolonged maintenance of the implant device 270 in the implanted location.
In some implementations, shunt devices/structures in accordance with embodiments of the present disclosure may be implanted in a wall separating the coronary sinus from the left atrium, such that interatrial shunting may be achieved through the coronary sinus.
In some cases, left-to-right shunting through implantation of the shunt device 80 in the wall 21 between the left atrium 2 and the coronary sinus 16 can be preferable to shunting through the atrial septum 18. For example, shunting through the coronary sinus 16 can provide reduced risk of thrombus and embolism. Generally, the coronary sinus can be less likely to have thrombus/emboli present for several reasons. First, the blood draining from the coronary vasculature into the right atrium 5 has just passed through capillaries, so it is essentially filtered blood. Second, the ostium 14 of the coronary sinus in the right atrium is often partially covered by a pseudo-valve called the Thebesian valve (not shown). The Thebesian valve is not always present, but some studies show it is present in most hearts and can block thrombus or other emboli from entering in the event of a spike in right atrial pressure. Third, the pressure gradient between the coronary sinus and the right atrium into which it drains is generally relatively low, such that thrombus or other emboli in the right atrium is likely to remain there. Fourth, in the event that thrombus/emboli do enter the coronary sinus, there is typically a much greater gradient between the right atrium and the coronary vasculature than between the right atrium and the left atrium. Most likely, thrombus/emboli would travel further down the coronary vasculature until right atrium pressure returned to normal and then the emboli would return directly to the right atrium.
Some additional advantages to locating the sensor implant device 80 in the wall between the left atrium and the coronary sinus relate to the consideration that such anatomy is generally more stable than the interatrial septal tissue. By diverting left atrial blood into the coronary sinus, sinus pressures may increase by a small amount. This can cause blood in the coronary vasculature to travel more slowly through the heart, possibly increasing perfusion and oxygen transfer, which can be more efficient and also can help a dying heart muscle to recover. In addition, by implanting the shunt device/structure 83 in the wall of the coronary sinus, damage to the atrial septum 18 may be prevented. Therefore, the atrial septum 18 may be preserved for later transseptal access for other therapies. The preservation of transseptal access may be advantageous for various reasons. For example, heart failure patients often have a number of other comorbidities, such as atrial fibrillation and/or mitral regurgitation; certain therapies for treating these conditions require a transseptal access.
It should be noted, that in addition to the various benefits of placing the sensor implant device 80 between the coronary sinus 16 and the left atrium 2, certain drawbacks may be considered. For example, by shunting blood from the left atrium 2 to the coronary sinus 16, oxygenated blood from the left atrium 2 may be passed to the right atrium 5 and/or non-oxygenated blood from the right atrium 5 may be passed to the left atrium 2, both of which may be undesirable with respect to proper functioning of the heart.
With further reference to
As with other embodiments, the sensor implant device 80 includes a sensor device 60 having a sensor transducer component 65 and certain connectivity component(s) (e.g., an antenna component and/or other control circuitry). The sensor implant device 80 is disposed, attached, and/or otherwise secured to or associated with one or more sensor arms 82 of an implant structure 81 (e.g., shunt structure) of the sensor implant device 80 in a manner such that the sensor transducer 65 is disposed radially outside of a channel area associated with the barrel/conduit portion 78 of the shunt structure 81. For example, the implant device 80 may be configured such that the sensor transducer component 65 is at least partially exposed on the atrial side of the tissue wall 21, as shown. With the sensor transducer component 65 disposed in the channel area of the shunt conduit 78, the sensor transducer 65 may advantageously be disposed in an area of flow that is relatively high, thereby allowing for sensor readings to be generated indicating characteristics of the flow through the conduit 78 of the shunt structure 81.
Interatrial shunting using the sensor implant device 80 may be well-suited for patients that are relatively highly sensitive to atrial pressure increases. For example, as pressure increases in the ventricles and/or atria and is applied against the myocardial cells, the muscles of the heart may generally be prone to contract relatively harder to process the excess blood. Therefore, as the ventricle dilates or stretches, for patients with compromised contractility of the ventricle, such patients may become more sensitive to higher pressures in the ventricle and/or atria because the heart may be unable to adequately respond or react thereto. Furthermore, increases in left atrial pressure can results in dyspnea, and therefore reduction in left atrial pressure to reduce dyspnea and/or reduce incidences of hospital readmission may be desirable through interatrial shunting. For example, when the ventricle experiences dysfunction such that is unable to accommodate build-up in fluid pressure, such fluid may backup into the atria, thereby increasing atrial pressure. With respect to heart failure, minimization of left ventricular end-diastolic pressure may be paramount. Because left ventricular end-diastolic pressure can be related to left atrial pressure, backup of fluid in the atrium can cause backup of fluid in the lungs, thereby causing undesirable and/or dangerous fluid buildup in the lungs. Interatrial shunting, such as using shunt devices in accordance with embodiments of the present disclosure, can divert extra fluid in the left atrium to the right atrium, which may be able to accommodate the additional fluid due to the relatively high compliance in the right atrium.
As with other embodiments, the sensor implant device 80 shown in
The sensor implant device 320 can be implanted in an atrial septum wall 318 such that the first sensor 360 and associated sensor transducer 365 are exposed in the left atrium 2, whereas the second sensor 362 and associated sensor transducer 367 are exposed to the right atrium 5.
In some embodiments, the shunt structure 390 and/or the sensor arms 392, 397 are formed from multiple/separate wires, rather than a single common wire as with certain other embodiments. For example, the shunt structure 390 may be made up of at least two separate wires, which may be coiled/wound together to provide the shunt structure 390. In some such embodiments, both/all wires may traverse the barrel portion 398 and may each have an end on each axial side of the shunt structure 390. In some embodiments, two separate wires of the shunt structure 390 may be helical (i.e., wound/coiled) in the same direction (e.g., both clockwise or counterclockwise winding in a given axial direction), or may be wound/coiled in opposite directions.
In some embodiments, the two sensor arms 392, 397 (or sensor arms 492, 497 of
Although the illustration of
With respect to multi-sensor implant devices in accordance with aspects of the present disclosure being implanted in an atrial septum, such sensor implant devices may be similar in certain respects to the implant device 420 of
Although
At block 1702, the process 1700 involves providing a delivery system 55 with a sensor implant device 70 disposed therein in a delivery configuration, such as a wireform shunt-type sensor implant device as disclosed in detail herein. Image 1802 of
The illustrated delivery system 55 includes an inner catheter 52, which may be disposed at least partially within the outer sheath 51 during one or more periods of the process 1700. In some embodiments, the shunt structure 90 of the sensor implant device 70 may be wound/disposed at least partially around the inner catheter 52, wherein the shunt structure 90 is disposed at least partially within the outer sheath 51 during one or more periods of the process 1700. For example, the inner catheter 55 may be disposed within at least the barrel portion 98 of the shunt structure 90, as shown.
In some embodiments, the delivery system 51 may be configured such that a guidewire 54 may be disposed at least partially therein. For example, the guidewire 54 may run in the area of an axis of the sheath 51 and/or inner catheter 52, such as within the inner catheter 52, as shown. The delivery system 55 may be configured to be advanced over the guidewire 54 to guide the delivery system 55 to a target implantation site.
Although not shown in
In some embodiments, the sensor implant device 70 may be disposed in the delivery system 55 with a sensor device 60, as described in detail herein, attached thereto or otherwise associated therewith. In some embodiments, the inner catheter 52 includes one or more sensor-accommodation features (not shown), such as one or more cut-outs, indentations, recesses, gaps, openings, apertures, holes, slits, or other features configured to accommodate the presence of the sensor device 60 and/or other feature(s) or aspect(s) of the implant device 70. Such sensor accommodation feature(s) may be longitudinal and circumferential cut-outs of the inner catheter 52, for example, and may be dimensioned to correspond to the size and/or profile of the sensor device and may allow for the sensor device to radially project into an inner diameter/space of the inner catheter 55. In some embodiments, as shown in image 1802, the sensor 60 and sensor-retention portion 93 of the sensor arm 92 may be disposed distally beyond the distal end of the inner catheter 52 when in the delivery configuration.
The sensor implant device 70 can be positioned within the delivery system 55 with a first/distal end thereof disposed distally with respect to the barrel 98 of the shunt structure 90. One or more of the distal coils/winds of the shunt structure 90 can be associated with and/or form a sensor arm 92 as described herein. Further, one or more of the winds/coils of the shunt structure 90 in a distal portion thereof can be associated with and/or form a distal flange or other end coil/form 94 when deployed and expanded. A second/proximal end can be positioned at least partially proximally with respect to the barrel 98 of the shunt structure 90 and/or the sensor device 60. One or more of the winds/coils of the shunt structure 90 in a proximal portion thereof can be associated with and/or form a proximal flange or other end coil/form 95 when deployed and expanded.
The outer sheath 50 may be used to transport the sensor implant device 70 to the target implantation site. That is, the sensor implant device 70 may be advanced to the target implantation site at least partially within a lumen of the outer sheath 51, such that the sensor implant device 70 is held and/or secured at least partially within a distal portion of the outer sheath 51.
The delivery system 55 can further include a pusher 53, which may comprise an at least partially hollow tube configured to slide over the inner catheter 52, wherein distal advancement of the pusher 53 relative to the inner catheter 52 when the distal end of the pusher 53 is in contact with the proximal end of the shunt structure 90 causes the shunt structure 90 to be moved over/off the inner catheter 52.
At block 1704, the process 1700 involves accessing a right atrium 5 of a heart of a patient using the delivery system 55 with the sensor implant device 70 disposed therein. In some implementations, accessing the cardiac anatomy with the delivery system 55 may be performed following one or more procedures or steps to place the guidewire 54 and/or form and/or dilate an opening in the atrial septum 18, such as in the area of the fossa ovalis 1811, the details of which are omitted for convenience and clarity.
At block 1706, the process 1700 involves advancing the delivery system 55 into the left atrium 2 through the atrial septum 18. Access to the septum 18 and left atrium 2 via the right atrium 5 may be achieved using any suitable or desirable procedure. For example, various access pathways may be utilized in maneuvering guidewires and catheters in and around the heart to deploy an expandable shunt integrated or associated with a pressure sensor in accordance with embodiments of the present disclosure. In some embodiments, access may be achieved through the subclavian or jugular vein into the superior vena cava (not shown) and from there into the right atrium 5. Alternatively, the access path may start in the femoral vein and through the inferior vena cava (not shown) into the heart. Other access routes may also be used, each of which may typically utilize a percutaneous incision through which the guidewire and catheter are inserted into the vasculature, normally through a sealed introducer, and from there the system may be designed or configured to allow the physician to control the distal ends of the devices from outside the body.
In some implementations, the guidewire 54 is introduced through the subclavian or jugular vein, through the superior vena cava 19, and into the right atrium 5. In some implementations, the guidewire 54 can be disposed in a spiral configuration within the left atrium 2, which may help to secure the guidewire in place. Once the guidewire 54 provides a path, an introducer sheath may be routed along the guidewire 54 and into the patient's vasculature, such as with the use of a dilator. The delivery catheter may be advanced through the superior vena cava to the right atrium 5, wherein the introducer sheath may provide a hemostatic valve to prevent blood loss. In some embodiments, a deployment catheter may function to form and prepare an opening in the septum 18, and a separate placement delivery system 55, as shown, is used for delivery of the sensor implant device 70. In other embodiments, the delivery system 55 may be used as the both the puncture preparation and implant delivery catheter with full functionality. In the present application, the term “delivery system” is used to represent a catheter or introducer with one or both of these functions.
Advancement of the delivery system 55 through the septum 18 may or may not be facilitated by a nosecone or other feature of the delivery system 55. With the delivery system 55 advanced through the septum 18, the sheath 51 may be open in the left atrium to allow for deployment of the sensor implant device 70 therefrom. The guidewire 54 may be disposed as running through the opening in the septum 18 prior to penetration thereof by the sheath 51. The opening in the septum 18 may originally be formed using a needle (not shown) associated with the delivery system 55 or other delivery system implemented prior to block 1706. In some implementations, the opening in the septum 18 may have been previously dilated using a balloon dilator or other instrument.
At block 1708, the process 1700 involves deploying the distal sensor arm 92 in the left atrium. For example, such operation(s) may involve deploying one or more distal coils or wire portions of the shunt structure 90, such that the coil(s) expand to form, or have emanate therefrom, the sensor arm 92. Furthermore, the distal wire portion/coil(s) can form a distal flange 94 of the sensor implant device 90 on the left atrial side of the septum 18. In some embodiments, no distal flange is implemented, but rather the sensor arm 92 serves as the tissue anchor securing the shunt structure 90 in place and/or keeping the shunt structure from being drawn/pushed back into the right atrium through the opening in the septum 18. Deploying the distal coil(s) and/or sensor arm 92 of the shunt structure 90 can be performed at least in part by advancing a pusher or other component of the delivery system 55 relative to the sheath 51. The anchor arm 92 can have associated therewith a sensor device 60, wherein a sensor transducer 65 of the sensor device 60 is exposed within the left atrium 2 such that the sensor transducer 65 can be used to obtain signals indicating physiological parameters associated with the left atrium, such as pressure.
At block 1710, the process 1700 involves deploying one or more proximal coils of the shunt structure 90 such that the coil(s) expand to form the proximal flange 95 on the right atrium side of the septum 18 to thereby sandwich portions of the septal wall 18 between the proximal flange 95 and the distal flange 94 and/or sensor arm 92 of the shunt structure 90. Such deployment of the coil(s) of the shunt structure 90 can be performed at least in part by advancing a pusher or other component of the delivery system 55 relative to the sheath 51 with the sheath 51 withdrawn back through the septum 18.
At block 1712, the process 1700 involves withdrawing the delivery system 55, leaving the sensor implant device 70 implanted in the septum 18, thereby allowing blood flow, to be shunted through the implant device 70 from the left atrium 2 into the right side of the heart. Although the implant device 70 is shown in the atrial septum 18, in some implementations, the implant device 70 may be positioned in a wall separating the left atrium 2 and coronary sinus, or between other cardiac chambers/vessels.
Although access to the left atrium is illustrated and described in connection with certain examples as being via the right atrium and/or vena cavae, such as through a transfemoral or other transcatheter procedure, other access paths/methods may be implemented in accordance with examples of the present disclosure. For example, in cases in which septal crossing through the interatrial septal wall is not possible, other access routes may be taken to the left atrium 2. In patients suffering from a weakened and/or damaged atrial septum, further engagement with the septal wall can be undesirable and result in further damage to the patient. Furthermore, in some patients, the septal wall may be occupied with one or more implant devices or other treatments, wherein it is not tenable to traverse the septal wall in view of such treatment(s). As alternatives to transseptal access, transaortic access may be implemented, wherein a delivery catheter 111c is passed through the descending aorta 32, aortic arch 12, ascending aorta, and aortic valve 7, and into the left atrium 2 through the mitral valve 6. Alternatively, transapical access may be implemented to access the target anatomy, as shown by delivery catheter 111d.
Depending on the embodiment, certain acts, events, or functions of any of the processes or algorithms described herein can be performed in a different sequence, may be added, merged, or left out altogether. Thus, in certain embodiments, not all described acts or events are necessary for the practice of the processes.
Conditional language used herein, such as, among others, “can,” “could,” “might,” “many,” “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is intended in its ordinary sense and is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment. The terms “comprising,” “including,” “having,” and the like are synonymous, are used in their ordinary sense, and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list. Conjunctive language such as the phrase “at least one of X, Y and Z,” unless specifically stated otherwise, is understood with the context as used in general to convey that an item, term, element, etc. may be either X, Y or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of X, at least one of Y and at least one of Z to each be present.
It should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, Figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than are expressly recited in that claim. Moreover, any components, features, or steps illustrated and/or described in a particular embodiment herein can be applied to or used with any other embodiment(s). Further, no component, feature, step, or group of components, features, or steps are necessary or indispensable for each embodiment. Thus, it is intended that the scope of the inventions herein disclosed and claimed below should not be limited by the particular embodiments described above, but should be determined only by a fair reading of the claims that follow.
It should be understood that certain ordinal terms (e.g., “first” or “second”) may be provided for ease of reference and do not necessarily imply physical characteristics or ordering. Therefore, as used herein, an ordinal term (e.g., “first,” “second,” “third,” etc.) used to modify an element, such as a structure, a component, an operation, etc., does not necessarily indicate priority or order of the element with respect to any other element, but rather may generally distinguish the element from another element having a similar or identical name (but for use of the ordinal term). In addition, as used herein, indefinite articles (“a” and “an”) may indicate “one or more” rather than “one.” Further, an operation performed “based on” a condition or event may also be performed based on one or more other conditions or events not explicitly recited.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The spatially relative terms “outer,” “inner,” “upper,” “lower,” “below,” “above,” “vertical,” “horizontal,” and similar terms, may be used herein for ease of description to describe the relations between one element or component and another element or component as illustrated in the drawings. It be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, in the case where a device shown in the drawing is turned over, the device positioned “below” or “beneath” another device may be placed “above” another device. Accordingly, the illustrative term “below” may include both the lower and upper positions. The device may also be oriented in the other direction, and thus the spatially relative terms may be interpreted differently depending on the orientations.
Unless otherwise expressly stated, comparative and/or quantitative terms, such as “less,” “more,” “greater,” and the like, are intended to encompass the concepts of equality. For example, “less” can mean not only “less” in the strictest mathematical sense, but also, “less than or equal to.”
This application is a continuation of International Patent Application No. PCT/US2022/018757, filed Mar. 3, 2022, and entitled SHUNT IMPLANT DEVICES WITH OFFSET SENSOR ARMS, which claims priority to U.S. Provisional patent application Ser. No. 63/161,356, filed Mar. 15, 2021 and entitled SHUNT IMPLANT DEVICES WITH OFFSET SENSOR ARMS, the complete disclosure of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63161356 | Mar 2021 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2022/018757 | Mar 2022 | US |
| Child | 18466676 | US |
