Portable ventricular assist system with multi-channel optical pressure sensor

Abstract

A portable ventricular assist system may include a cardiac pump and at least one hardware controller. The heart pump may include: a rotor; a motor configured to drive rotation of the rotor at one or more speeds; a first optical pressure sensor configured to detect a first pressure signal; and a second optical pressure sensor configured to detect a second pressure signal. The at least one hardware controller may include: a primary power source; an auxiliary power supply; at least one light emitting diode (LED) coupled to the first optical pressure sensor via at least one first optical fiber and to the second optical pressure sensor via at least one second optical fiber. The at least one hardware controller may further include at least one hardware processor configured to determine a differential pressure based at least in part on the first pressure signal and the second pressure signal.

Description

Technical Field

[0001] The present disclosure relates to a portable ventricular assist system. Background Art

[0002] Fluid pumps, such as blood pumps, are used in the medical field for a wide range of applications and purposes. An intravascular blood pump is a pump that can be advanced through a patient's vasculature (i.e., veins and / or arteries) to a location in the patient's heart or other location within the patient's circulatory system. For example, an intravascular blood pump can be inserted via a catheter and positioned to span a heart valve. An intravascular blood pump is typically disposed at the end of a catheter. Once in position, the pump can be used to assist the heart and pump blood through the circulatory system and thereby temporarily reduce the workload on the patient's heart so that the heart can recover after a heart attack. An exemplary intravascular blood pump is available from ABIOMED, ​​Inc., Danvers, MA, under the trade name A heart pump was purchased.

[0003] Such a pump can be positioned, for example, in a cardiac chamber, such as the left ventricle, to assist the heart. In this case, the blood pump can be inserted through a hollow catheter via the femoral artery and introduced upward into the left ventricle of the patient's heart. The blood pump inlet draws blood from this location, and the blood pump outlet discharges blood into the aorta. In this way, the function of the heart can be replaced or at least assisted by the operation of the pump.

[0004] The intravascular blood pump is typically connected to a corresponding external heart pump controller that controls the heart pump (e.g., motor speed) and collects and displays operational data about the blood pump (e.g., cardiac signal level, battery temperature, blood flow rate, and pumping integrity). An exemplary heart pump controller is available from ABIOMED Corporation under the trade name Automated Impella When the value of the operational data drops beyond a predetermined value or range (e.g., if a leak, aspiration, and / or pump failure is detected), the controller may issue an alarm. The controller may include and / or be coupled to a video display screen on which a graphical user interface configured to display the operational data and / or alarms is displayed. Summary of the Invention

[0005] Described herein are systems and methods for a portable heart pump system that includes a multi-channel optical pressure sensor. In some embodiments, the multi-channel optical pressure sensor can be incorporated into a heart pump of the portable heart pump system. When incorporated into the portable heart pump system, the multi-channel optical pressure sensor can be used to sense differential pressure, for example, across the aortic valve, while the heart pump is positioned within a patient's heart. The differential pressure measurement can be used, for example, to calculate blood flow rate through the heart pump during operation of the heart pump.

[0006] In some embodiments, a portable ventricular assist system is provided. The portable ventricular assist system includes a heart pump and at least one hardware controller, the heart pump comprising: a rotor; a motor configured to drive the rotation of the rotor at one or more speeds; a first optical pressure sensor configured to detect a first pressure signal; and a second optical pressure sensor configured to detect a second pressure signal. The at least one hardware controller includes: a primary power supply; an auxiliary power supply; at least one light emitting diode (LED) coupled to the first optical pressure sensor via at least one first optical fiber and to the second optical pressure sensor via at least one second optical fiber; and at least one hardware processor configured to determine a differential pressure based at least in part on the first and second pressure signals.

[0007] In one aspect, the portable ventricular assist system further includes a connector configured to connect the heart pump to the at least one hardware controller. The connector includes at least one electrical connection connecting the primary power source and / or the auxiliary power source to the motor, and at least one optical connection connecting the at least one LED to the first optical pressure sensor and the second optical pressure sensor. In one aspect, the at least one hardware controller further includes a bus system configured to manage power supplied to the motor by the primary power source and / or the auxiliary power source. In one aspect, the bus system is configured to automatically switch power provided from the primary power source to the auxiliary power source when a state of charge is less than a threshold amount.

[0008] In one aspect, the portable ventricular assist system further includes at least one indicator LED configured to indicate a current charge state of the primary power source and / or the auxiliary power source. In one aspect, the portable ventricular assist system further includes a communication circuit system configured to provide information to a computing device for display, the information including one or more quantities associated with the operation of the heart pump. In one aspect, the one or more quantities include a motor current amount associated with the operation of the heart pump. In one aspect, the one or more quantities include one or more physiological quantities associated with a patient when the heart pump is in operation. In one aspect, the one or more physiological quantities include a differential pressure measurement across the patient's aortic valve. In one aspect, the communication circuit system is configured to provide the information to the computing device wirelessly.

[0009] In some embodiments, a multi-channel optical pressure sensor is provided. The multi-channel optical sensor includes: at least one light emitting diode (LED); a plurality of sensors, including a first sensor coupled to the at least one LED via at least one first optical fiber and a second sensor coupled to the at least one LED via at least one second optical fiber; a detector module coupled to the first sensor and the second sensor, the detector module including at least one lens and an image sensor configured to sense light received from the at least one lens; and at least one hardware processor configured to determine a first pressure measured at the first sensor and a second pressure measured at the second sensor based at least in part on the light sensed by the image sensor.

[0010] In one aspect, the at least one LED comprises a first LED configured to generate first light having a first spectrum, and a second LED configured to generate second light having a second spectrum. In one aspect, the first spectrum has a peak wavelength in the range of 550 nm to 600 nm and the second spectrum has a peak wavelength in the range of 800 nm to 900 nm. In one aspect, the first spectrum has a peak wavelength in the range of 590 nm to 610 nm and the second spectrum has a peak wavelength in the range of 820 nm to 850 nm. In one aspect, the first spectrum has a peak wavelength that is 4 / 5 of the peak wavelength of the second spectrum. In one aspect, the first LED and / or the second LED are less than 1 mm. In one aspect, the first LED and / or the second LED are phosphor-converted LEDs. In one aspect, the at least one LED comprises a single LED having a broad spectrum.

[0011] In one aspect, the sensor further includes a first optical element disposed between the at least one LED and the plurality of sensors. The first optical element is configured to receive the first light and the second light and output third light and fourth light, each of the third light and the fourth light having a third spectrum. In one aspect, the sensor further includes a second optical element coupled to the first optical element, the first sensor, and the detector module, and a third optical element coupled to the first optical element, the second sensor, and the detector module. In one aspect, the second optical element is configured to provide the first reflected light from the first sensor to the detector module, and the third optical element is configured to provide the second reflected light from the second sensor to the detector module.

[0012] In one aspect, the at least one lens comprises a plano-convex lens. In one aspect, the plano-convex lens comprises a set of D-shaped lenses having curved edges facing each other. In one aspect, the at least one lens is configured to reduce spherical aberration in the light received from the first sensor and the second sensor. In one aspect, the detector module further comprises a Fizeau interferometer disposed between the at least one lens and the image sensor. In one aspect, the image sensor comprises a two-dimensional image sensor. In one aspect, the at least one lens and the Fizeau interferometer are configured to jointly project the light received from the first sensor and the second sensor as two lines onto the two-dimensional image sensor. In one aspect, the two lines are two parallel lines. In one aspect, each of the two lines on the two-dimensional image sensor comprises an interference pattern, and wherein determining a first pressure measured at the first sensor and a second pressure measured at the second sensor based at least in part on the light sensed by the image sensor comprises determining the first pressure and the second pressure based on corresponding interference patterns.

[0013] In some embodiments, a circulatory support device is provided. The circulatory support device includes: a rotor; a motor configured to drive the rotor to rotate at one or more speeds; a first optical pressure sensor configured to detect a first pressure signal; a second optical pressure sensor configured to detect a second pressure signal; and at least one hardware processor. The at least one hardware processor is configured to determine a differential pressure signal based at least in part on the first and second pressure signals.

[0014] In one aspect, the at least one hardware processor is further configured to determine a flow rate through the circulatory support device based at least in part on the differential pressure signal. In one aspect, the circulatory support device further comprises: a first light emitting diode (LED) coupled to the first optical pressure sensor and the second optical pressure sensor, the first LED configured to generate a first light having a first spectrum; and a second LED coupled to the first optical pressure sensor and the second optical pressure sensor, the second LED configured to generate a second light having a second spectrum. In one aspect, the first spectrum has a peak wavelength within a range of 550 nm to 600 nm, and the second spectrum has a peak wavelength within a range of 800 nm to 900 nm. In one aspect, the first spectrum has a peak wavelength within a range of 590 nm to 610 nm, and the second spectrum has a peak wavelength within a range of 820 nm to 850 nm. In one aspect, the first spectrum has a peak wavelength that is 4 / 5 of the peak wavelength of the second spectrum. In one aspect, the first LED and / or the second LED are less than 1 mm. In one aspect, the first LED and / or the second LED are phosphor-converted LEDs.

[0015] In one aspect, the circulatory support device further includes a first optical element arranged to receive the first light and the second light and output third light and fourth light, each of the third light and the fourth light having a third spectrum, the third light being provided to the first optical pressure sensor and the fourth light being provided to the second optical pressure sensor. In one aspect, the circulatory support device further includes a second optical element coupled to the first optical element and the first optical pressure sensor, and a third optical element coupled to the first optical element and the second optical pressure sensor. In one aspect, the circulatory support device further includes a detector module, wherein the second optical element is configured to provide first reflected light from the first optical pressure sensor to the detector module, and the third optical element is configured to provide second reflected light from the second optical pressure sensor to the detector module.

[0016] In one aspect, the circulatory support device further includes a detector module coupled to the first optical pressure sensor and the second optical pressure sensor. The detector module includes at least one lens and an image sensor configured to sense light received from the at least one lens. In one aspect, the at least one lens includes a plano-convex lens. In one aspect, the plano-convex lens includes a set of D-shaped lenses having curved edges facing each other. In one aspect, the at least one lens is configured to reduce spherical aberration in the light received from the first optical pressure sensor and the second optical pressure sensor.

[0017] In one aspect, the detector module further includes a Fehzow interferometer disposed between the at least one lens and the image sensor. In one aspect, the image sensor includes a two-dimensional image sensor. In one aspect, the at least one lens and the Fehzow interferometer are configured to jointly project the light received from the first and second optical pressure sensors as two lines onto the two-dimensional image sensor. In one aspect, the two lines are two parallel lines. In one aspect, each of the two lines on the two-dimensional image sensor includes an interference pattern, the at least one hardware processor is further configured to determine a first pressure measured at the first optical pressure sensor and a second pressure measured at the second optical pressure sensor based at least in part on the light sensed by the image sensor by determining the first pressure and the second pressure based on the corresponding interference pattern, and determining the differential pressure signal based at least in part on the first pressure signal and the second pressure signal includes determining the differential pressure signal based on the first pressure and the second pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1A An illustrative circulatory support device that may be used in accordance with some embodiments is shown.

[0019] Figure 1B Description of the location within the patient's heart Figure 1A circulatory support device.

[0020] Figure 1C Description contains Figure 1A The ventricular support system of the circulatory support device.

[0021] Figure 2 A circulatory support device including a multi-channel optical pressure sensor is described according to some embodiments.

[0022] Figure 3 Components of a multi-channel optical pressure sensor system are described in accordance with some embodiments.

[0023] Figure 4 A detector module for a multi-channel optical pressure sensor system is schematically illustrated according to some embodiments.

[0024] Figure 5 Schematic illustration of the process of generating an interferogram using a single-channel optical pressure sensor system.

[0025] Figure 6A Description available for Figure 5 Spectrum (top) and interferogram signal (bottom) of a broadband white light source in a single-channel optical pressure sensor.

[0026] Figure 6B Illustrated are the optical spectrum (top) and interferogram signal (bottom) of a dual-LED light source that may be used in a multi-channel optical pressure sensor system, according to some embodiments.

[0027] Figure 7A Illustrated is a display of an interferogram signal recorded using a two-dimensional image sensor of a multi-channel optical pressure sensor system, according to some embodiments.

[0028] Figure 7B Description from Figure 7A Interferogram signal extracted from image sensor data shown in .

[0029] Figure 8 A portable ventricular assist system according to some embodiments is schematically illustrated. DETAILED DESCRIPTION

[0030] A circulatory support device (also referred to herein as a "heart pump" or simply a "pump") may include a percutaneous, catheter-based device that provides hemodynamic support to a patient's heart. A ventricular support system may desirably be portable so that, while the heart pump is inserted into the patient's heart, the patient can freely move around and continue to perform their daily activities. As described in more detail herein, some existing ventricular support systems include a heart pump configured to be positioned within the patient's heart, and a controller coupled to the heart pump and configured to provide power to the heart pump and control one or more operational aspects of the heart pump (e.g., pump speed). In addition, the controller may be configured to measure one or more quantities associated with the operation of the heart pump. For example, the controller may be configured to measure quantities associated with the operation of the heart pump (e.g., motor current associated with the operation of the motor). The controller may also be configured to measure one or more physiological quantities associated with the patient while the heart pump system is in operation. For example, the measured physiological quantities may include, but are not limited to, pressure measurements in the aorta and / or left ventricle, so that the differential pressure across the aortic valve can be determined. In a ventricular support system that includes only a single pressure sensor, the differential pressure across the aortic valve can be estimated indirectly from the single pressure sensor signal (e.g., located in the aorta) and the motor current of the heart pump. To facilitate portability, the controller of the ventricular support system should be small, lightweight, and / or designed for low-power operation to conserve battery power. Some embodiments of the technology described herein provide a portable ventricular support system that incorporates a portable (e.g., wearable) controller coupled to an implanted heart pump.

[0031] As will be appreciated, in order for a heart pump to function properly, it should be correctly positioned in the patient's heart, with the inlet portion of the pump positioned in the left ventricle and the outlet portion of the pump positioned in the aorta, thereby spanning the aortic valve of the patient's heart. Figure 1AAs shown in FIG, heart pump 110 may include a pigtail 111, an inlet region 112, a cannula 113, a pressure sensor 114, an outlet region 115, a motor housing 116, and / or a catheter 117. Pigtail 111 may help stabilize heart pump 110 in the patient's heart. It should be understood that some embodiments of heart pump 110 may not include pigtail 111 and that heart pump 110 may be stabilized in other ways or not at all. During operation, blood may be drawn into one or more openings in inlet region 112, directed through cannula 113, and expelled through one or more openings in outlet region 115 by a motor (not shown) disposed in motor housing 116. In some embodiments, pressure sensor 114 may include a flexible diaphragm integrated into cannula 113. One side of pressure sensor 114 may be exposed to blood pressure outside cannula 113, and the other side may be exposed to blood pressure inside cannula 113. In some such embodiments, pressure sensor 114 can generate an electrical signal proportional to the difference between the pressure outside cannula 113 and the pressure inside cannula 113. In some embodiments, pressure sensor 114 can include an optical pressure sensor. Catheter 117 can provide a connection between heart pump 110 and one or more other devices of a ventricular support system (examples of which are described in

[0044] ). Figure 1C One or more fluid and / or electrical connections between ).

[0032] like Figure 1B , the heart pump 110 can be positioned in the patient's heart 120. For example, the heart pump 110 can be percutaneously inserted via the femoral artery 122 into the ascending aorta 124, across the aortic valve 126, and into the left ventricle 128. In other embodiments, the heart pump can be percutaneously inserted, for example, via the axillary artery 123 into the ascending aorta 124, across the aortic valve 126, and into the left ventricle 128. In other embodiments, the heart pump can be inserted, for example, directly into the ascending aorta 124, across the aortic valve 126, and into the left ventricle 128. During operation, the heart pump 110 can entrain blood from the left ventricle 128 and expel the blood into the ascending aorta 124. Thus, the heart pump 110 can perform some of the work normally performed by the patient's heart 120. The hemodynamic effects of the cardiac pump may include an increase in cardiac output and improved coronary blood flow, leading to a decrease in left ventricular end-diastolic pressure, pulmonary capillary wedge pressure, myocardial workload, and oxygen consumption.

[0033] like Figure 1C As shown in FIG, heart pump 110 may form part of ventricular support system 100. Ventricular support system 100 may also include controller 130 (e.g., Automated Impella 1. The controller 130 includes a display 140, an irrigation subsystem 150, a connector cable 160, a plug 170, and a repositioning unit 180. As shown, the controller 130 may include the display 140. The controller 130 monitors and controls the operation of the heart pump 110. During operation, the irrigation subsystem 150 may be configured to deliver an irrigation fluid to the heart pump 110 through the conduit 117 to prevent blood from entering the motor (not shown) within the motor housing 116. In some embodiments, the irrigation fluid is a glucose solution (e.g., 5% glucose in water with 25 IU / mL or 50 IU / mL of heparin). The connector cable 160 may provide an electrical connection between the heart pump 110 and the controller 130. The plug 170 may connect the conduit 117, the irrigation subsystem 150, and the connector cable 160. In some embodiments, the plug 170 includes a storage device (e.g., a memory) configured to store, for example, operating parameters to facilitate transfer of the patient to another controller as needed. Repositioning unit 180 may be used to reposition heart pump 110 within the patient's heart.

[0034] In some embodiments, one or more aspects of controller 130 are configured to support a portable ventricular support system 100. For example, while existing controllers may be configured to plug into a standard wall outlet to power heart pump 110, a controller 130 designed to be portable may additionally or alternatively be configured to include one or more batteries (e.g., rechargeable batteries) configured to power the motor of heart pump 110 via connector cable 160. While including multiple batteries in controller 130 may increase the weight of the controller, in some embodiments, it is important that the portable ventricular support system include an auxiliary power source if the primary power source fails or becomes too discharged to provide sufficient power to the heart pump. In some embodiments, controller 130 may be configured to automatically switch to the auxiliary power source when the primary power source has a charge level below a specific level (e.g., 10%) to ensure continued operation of the heart pump. In some embodiments, the primary and / or auxiliary power sources may be rechargeable and / or removable, for example, to facilitate charging. For example, one or more batteries may be incorporated into a battery pack that can be attached / removed from the controller 130. In some embodiments, the controller 130 includes multiple ports to which the battery packs can be coupled. The primary power source and the auxiliary power source may be incorporated into a single battery pack or may be provided using separate battery packs. In some embodiments, the controller 130 may be configured to include one or more light sources (e.g., LEDs) configured to display the current charge state of the primary and / or auxiliary power sources.

[0035] As described herein, other aspects of the controller 130 may also be designed for portability. For example, the controller 130 may include one or more light sources configured to provide light to one or more optical pressure sensors. To facilitate low-power operation, the light sources may be configured as light-emitting diodes (LEDs), which consume substantially less power than conventional tungsten-based light sources. In some embodiments, the controller may include a bus system configured to facilitate power management within the controller and / or provided to the motor of the heart pump.

[0036] In some embodiments, the display 140 may be simplified and / or eliminated as part of the controller 130 to further improve the portability of the ventricular support system. For example, the controller 130 may include a display 140 that is smaller and / or simpler than that used in conventional controllers (e.g., AICs). The smaller / simpler display 140 may be arranged on a portable controller 130 that is configured to be worn (e.g., on a patient's belt / waist). In some embodiments, the controller 130 may be configured without the display 140. Alternatively, the controller 130 may be configured with a communication component (e.g., configured to implement a short-range communication protocol such as Bluetooth). The communication component may be configured to communicate wirelessly with an application on a computing device (e.g., a smartphone, laptop, or tablet computing device). The computing device may be configured to display the information using the computing device's display when receiving information from the controller 130. In some embodiments, the computing device may be configured to present a programming interface to enable an authorized user to change one or more operating parameters of the controller (e.g., pump speed). In this way, the patient or another authorized user may be able to modify the operation of the heart pump (e.g., within limits specified by a healthcare professional) without having to go to a hospital, clinic, or other medical facility to have the ventricular support device reprogrammed by a healthcare professional. This programming interface may employ security measures to help ensure that a third party cannot easily hack the interface.

[0037] In some embodiments, the portability of the ventricular support system can be improved by reducing the weight of controller 130. For example, the maximum weight of controller 130 can be 3 kg to 4 kg, so that controller 130 can be worn by the patient. In some embodiments, the weight of controller 130 can be reduced from the weight of a conventional AIC in a variety of ways, including but not limited to having a smaller display or no display, having fewer ports to which external devices can be connected, and / or having removable components (e.g., an additional battery pack).

[0038] As shown, in some embodiments, the ventricular support system may include an irrigation subsystem 150 having a container 151, a supply line 152, an irrigation cassette 153, an irrigation tray 154, irrigation tubing 155, a check valve 156, a pressure reservoir 157, an infusion filter 158, and a sidearm 159. Container 151 may be, for example, a bag or a bottle. As will be appreciated, in other embodiments, the ventricular support system may not include an irrigation subsystem. In some embodiments, irrigation fluid may be stored in container 151. Supply line 152 may provide a fluid connection between container 151 and irrigation cassette 153. Flush cassette 153 may control how irrigation fluid in container 151 is delivered to heart pump 110. For example, irrigation cassette 153 may include one or more valves for controlling the pressure and / or flow rate of the irrigation fluid. Flush tray 154 may include one or more pressure and / or flow sensors for measuring the pressure and / or flow rate of the irrigation fluid. As shown, the controller 130 may include a flush cassette 153 and a flush tray 154. Flush tubing 155 may provide a fluid connection between the flush tray 154 and a check valve 156. A pressure reservoir 157 provides additional fill volume during flush fluid changes. In some embodiments, the pressure reservoir 157 includes a flexible rubber diaphragm that provides additional fill volume through an expansion chamber. An infusion filter 158 helps prevent bacterial contamination and air from entering the catheter 117. A side arm 159 provides a fluid connection between the infusion filter 158 and the plug 170.

[0039] Although shown as having separate irrigation tubing and connector cables, it will be appreciated that in some embodiments, the ventricular support system may include a single connector having both fluid and electrical lines that can be connected to controller 130. In some embodiments, the connector may be designed to facilitate portability and / or modularity of the ventricular support system. For example, the connector is configured to have one or more universal or standard compliant ports to enable the heart pump to be used interchangeably with multiple controllers and / or heart pumps. Such versatility of the connector can enable a modular ventricular support system within which components, such as controller 130, can be more easily swapped out for a new controller if the currently connected controller has a malfunction or is otherwise inadequate to maintain proper operation of the heart pump coupled thereto.

[0040] During operation, the controller 130 can be configured to receive measurements from the pressure sensor 114 and the flush tray 154 and control the operation of the motor (not shown) and the flush cassette 153 within the motor housing 116. As mentioned above, the controller 130 can be configured to control and measure the pressure and / or flow rate of the flush fluid through the flush cassette 153 and the flush tray 154. During operation, after exiting the flush subsystem 150 through the side arm 159, the flush fluid can be directed through an irrigation lumen (not shown) and plug 170 within the conduit 117. A sensor cable (not shown), a connector cable 160, and plug 170 within the conduit 117 can provide an electrical connection between the pressure sensor 114 and the controller 130. A motor cable (not shown), a connector cable 160, and plug 170 within the conduit 117 can provide an electrical connection between the motor within the motor housing 116 and the controller 130. During operation, the controller 130 may be configured to receive measurements from the pressure sensor 114 via a sensor cable (e.g., fiber optic) and control power delivered via a motor cable to the motor within the motor housing 116. By controlling the power delivered to the motor within the motor housing 116, the controller 130 may be operable to control the speed of the motor within the motor housing 116.

[0041] Various modifications may be made to ventricular support system 100 and one or more of its components. For example, one or more additional sensors may be added to heart pump 100. In another example, a signal generator may be added to heart pump 100 to generate a signal indicating the rotational speed of the motor within motor housing 116. As another example, one or more components of ventricular support system 100 may be separated. For example, display 140 may be incorporated into another device that communicates with controller 130 (e.g., wirelessly or via one or more cables).

[0042] As described herein, a heart pump (e.g., heart pump 110) may include a pressure sensor 114 (e.g., an optical pressure sensor) configured to detect pressure within the aorta of a patient's heart when the heart pump is properly positioned. The pressure signal sensed by pressure sensor 114 may be used, at least in part, to determine the proper positioning of the heart pump within the patient's heart and / or to determine the blood flow rate through the heart pump when the heart pump is operating. For example, the pressure signal may be used in conjunction with a motor current signal received from a motor current sensor (not shown) and a set of stored values ​​to determine the flow rate through the heart pump. The differential pressure across the aortic valve may also be indirectly determined based on the pressure signal measuring the pressure in the aorta and the set of stored values.

[0043] In some embodiments, one or more additional pressure sensors may be incorporated into the heart pump 110, for example, to directly sense pressure in both the aorta and the left ventricle, rather than having to infer pressure in the left ventricle based on a pressure sensor signal sensed in the aorta, as discussed herein. The use of multiple pressure sensors is also referred to herein as implementing a multi-channel pressure sensor. Figure 2 An embodiment of a heart pump 200 is described in which a second pressure sensor 210 is disposed near the inlet region 112. When properly positioned within the patient's heart, the second pressure sensor 210 can be configured to measure a pressure sensor signal used to determine left ventricular blood pressure. In such an embodiment, an additional sensor cable (e.g., an optical fiber) can be disposed within the catheter 117 to provide a connection between the second pressure sensor 210 and a controller (e.g., the controller 130).

[0044] The present inventors have recognized and appreciated that, in order to accommodate multiple pressure sensors within a heart pump, it may be useful to provide lower power and / or smaller pressure sensors than those used in some conventional heart pumps, including, for example, pressure sensor 114. Furthermore, the use of optically based pressure sensors may have advantages over electronic or other types of pressure sensors, including, but not limited to, their smaller size, their small or negligible pressure drift, and their durability. Figure 3 A multi-channel pressure sensor system 300 designed in accordance with some embodiments of the present technology is schematically illustrated. System 300 includes a light source 310 and multiple optical sensors (e.g., a first sensor 340 and a second sensor 360) coupled via optical fibers and one or more optical elements. In the exemplary system 300, light source 310 includes two light-emitting diodes (LEDs) (i.e., a first LED 312 and a second LED 314) configured to output light having different spectra. As described in more detail below, the spectra of light output from first LED 312 and second LED 314 can be selected so that their combined output has some properties similar to white light produced, for example, by a tungsten lamp. In some embodiments, the size of the LEDs can be less than 1 mm. Such properties can facilitate the use of lower-power LED light sources for performing multi-channel optical pressure sensing in heart pumps in accordance with the techniques described herein. Low-power LED light sources can be particularly beneficial in providing portable ventricular assist systems, where the power budget must be carefully managed to ensure that the primary and auxiliary power supplies in the portable system are not rapidly discharged.

[0045] As shown, system 300 includes a plurality of optical elements arranged between a light source 310 and a plurality of sensors (e.g., sensors 340, 360). A first optical element 320 is arranged to receive light from a first LED 312 and a second LED 314. In some embodiments, first optical element 320 is implemented as a splitter that mixes the light from first LED 312 and second LED 314 and provides the light at its output to a second optical element 330 and a third optical element 350. The light provided as input to second optical element 330 and third optical element 350 may have a blended or "mixed" spectrum from the light output from first LED 312 and second LED 314, and may have half the power of the light provided as input from light source 310 to first optical element 320. By mixing the light from first LED 312 and second LED 314, first optical element 320 provides light having a spectrum that shares some characteristics with white light that can be produced with higher power (e.g., tungsten-based) light sources. It should be understood that other types of light sources and / or optical components may alternatively be used to generate light for use with some embodiments. For example, a single low-power light source 310 configured to generate light having multiple spectra or a complex spectrum having some characteristics in common with white light (e.g., light having a broad spectrum) may alternatively be used. In this embodiment, a first optical element 320 configured to mix light from multiple light sources (e.g., LED 312 and LED 314) may not be required, and the light output from the single light source may be provided directly to the second optical element 330 and the third optical element 350 via one or more optical fibers.

[0046] In some embodiments, second optical element 330 may be implemented as a splitter that provides mixed spectral light output from first optical element 320 to first sensor 340. First sensor 340 may be configured as a reflective element such that at least some of the light provided to first sensor 340 is reflected back by second optical element 330, with second optical element 330 providing the reflected light as input to detector module 370. Similarly, third optical element 350 may be implemented as a splitter that provides mixed spectral light output from first optical element 320 to second sensor 360. Second sensor 360 may be configured as a reflective element such that at least some of the light provided to second sensor 360 is reflected back by third optical element 350, with third optical element 350 providing the reflected light as input to detector module 370. In this manner, the reflected light signals provided by first and second sensors 340, 360 are further processed by components of detector module 370. In some embodiments, the first optical fiber coupled between the second optical element 330 and the detector module 370 and the second optical fiber coupled between the third optical element 350 and the detector module 370 may be coupled to the detector module 370 via connectors configured to arrange the first optical fiber and the second optical fiber in close proximity to each other.

[0047] As shown, the detector module 370 may include one or more lenses 372 (e.g., plano-convex lenses, aspheric lenses, bi-convex lenses, etc.), a Fehzo interferometer 374, and an image sensor 376. In some embodiments, the lenses 372 may be implemented as a pair of D-shaped lenses facing each other, as described in further detail herein. The lenses 372 can be used to reduce spherical aberration so that multiple channels of light reflected from the sensor can be separated in space and represented on the detector as two (or more) parallel or nearly parallel lines with limited crosstalk between them. The light received by the lenses 372 is provided as input to the Fehzo interferometer 374. The Fehzo interferometer 374 can be implemented as two mirrors with a spatially varying dielectric layer disposed therebetween. Light entering the Fehzo interferometer 374 can resonate at specific locations on the spatially varying dielectric layer to produce a light beam captured by the image sensor 376, for example, as Figure 7AIn some embodiments, the image sensor 376 may be configured as a two-dimensional image sensor on which a plurality of optical channels corresponding to the interference pattern of the reflected light signals from the first sensor 340 and the second sensor 360 are detected. The system 300 may further include at least one hardware processor 380 configured to analyze the signals captured by the image sensor 376 to determine the pressure sensed by each of the first sensor 340 and the second sensor 360 based on the interference pattern signals captured by the image sensor 376, for example. In some embodiments, the at least one hardware processor 380 may be implemented as described above in conjunction with Figure 1C Portions of controller 130 are described.

[0048] Figure 4 The arrangement of components of the detector module 370 according to some embodiments is schematically illustrated. As shown, the detector module 370 includes a Figure 3 A connector 410 for the optical fibers of the second optical element 330 and the third optical element 350 is depicted. Connector 410 can be configured to place the incoming optical fibers in close proximity to each other. The two light beams output from connector 410 are provided to lens 372 to focus the light onto a Feyzo interferometer 374, which redirects the light onto the surface of an image sensor 376. In some embodiments, connector 410 can be moved in a plane parallel to lens 372 to adjust the focus of the light beams on image sensor 376. As shown, lens 372 can be implemented as a set of D-shaped lenses with curved edges oriented toward each other. Lens 372 can be configured to reduce spherical aberration that would occur, for example, if a rod lens were used.

[0049] Figure 5 The process of performing interferometry using an optical system such as the one described herein is schematically illustrated. Figure 5 In the example of using a white light source (e.g., a tungsten lamp) as the light source (e.g., Figure 3 310 in FIG. 31). However, it will be appreciated that other light sources (e.g., LEDs 312, 314) may be used instead. As shown, light generated by the light source is provided as incident light 10 to the sensor (e.g., Figure 3 As shown, the sensor may be implemented as a transducer sensing interferometer. rThe pressure is provided to a detector module (e.g., detector module 370), which includes a tuning wedge (e.g., FitzGerald interferometer 374) for generating an interferogram signal (e.g., on image sensor 376). The central peak of the interferogram signal can be tracked and / or otherwise used to determine the pressure value sensed by the sensor.

[0050] As discussed herein, the present inventors have recognized and appreciated that some conventional white light sources generate a significant amount of heat and use a significant amount of electricity, which limits their use in certain embodiments, including as a light source for a multi-channel optical pressure sensor for a portable ventricular assist system. Therefore, in some embodiments, one or more lower power light sources can be used to provide light with some properties similar to white light. For example, as described above in conjunction with Figure 3 As described in the system 300 shown in FIG, two LED light sources configured to generate light having different spectra may be used.

[0051] Figure 6A Plots showing the spectrum of light output by a white light source (top plot) and the corresponding interferogram signal recorded using the white light source (bottom plot). As shown, conventional white light sources have a broadband spectrum, which produces an interferogram signal with a well-defined central region with small side lobes. This interferogram signal is ideal for determining the pressure sensed by the coupled optical pressure sensor. Figure 6B Plots showing the spectra of light output by two narrowband LED light sources (top plot) and the corresponding interferogram signals recorded using the two LED light sources (bottom plot). The spectrum of light generated by the first LED light source can have a lower peak wavelength (e.g., in the range of 550 nm to 650 nm), and the spectrum of light generated by the second LED light source can have a higher peak wavelength (e.g., in the range of 800 nm to 900 nm). In some embodiments, the spectrum of light generated by the first LED light source has a peak wavelength in the range of 550 nm to 610 nm, and the spectrum of light generated by the second LED light source has a peak wavelength in the range of 820 nm to 850 nm. In some embodiments, the peak wavelength of the first LED light source is 4 / 5 of the peak wavelength of the second LED light source.

[0052] like Figure 6B The bottom plot of shows that using two narrowband LED sources produces an interferogram signal similar to that produced using Figure 6A Some characteristics of the interferogram signal produced by the broadband white light source are shown in . For example, Figure 6B The interferogram signal shown in Figure 6AThe central portion of the interferogram signal shown in FIG, and the lateral envelope that distinguishes the central region from the rest of the signal. When the lateral envelope adjacent to the central portion of the signal drops sufficiently to enable tracking of the central portion of the signal relative to the rest of the signal, Figure 6B The interferogram signal shown in can be similar to Figure 6A The interference pattern signal shown in Figure 5 Thus, some embodiments emulate the use of a broadband white light source by using multiple narrowband and relatively low-power LED light sources that, when used in combination, produce an interferogram signal that can be used in a multi-channel optical pressure sensor (e.g., for a heart pump). In some embodiments, one or more characteristics (e.g., amplitude, position) of a central peak in a central portion of the interferogram signal can be used to determine the pressure value sensed by the corresponding pressure sensor associated with the interferogram signal. It should be understood that in some embodiments, more than two light sources (e.g., LEDs) can be used, and the embodiments are not limited in this respect. Thus, while a dual-channel optical pressure sensor system is shown and described herein, any multi-channel (e.g., two or more channels) optical pressure sensor system can be implemented using techniques similar to those described herein. More than two light sources can be beneficial in embodiments where more than two channels are used so that the power of the optical signal provided to each sensor is sufficient to produce a reliable interferogram signal.

[0053] Figure 7A The following describes a method for representing a display image of a 2D image sensor (e.g., Figure 3 7. As shown, the interferogram signals captured by the image sensor for each corresponding optical sensor are represented as lines. For example, a first interferogram signal corresponding to reflected light from sensor 340 may be represented as line 710 and a second interferogram signal corresponding to reflected light from sensor 360 may be represented as line 720. As described herein, the components of the detector module may enable the interferogram signals represented as lines 710 and 720 to be spatially distinguishable and separable (e.g., with no or limited crosstalk). It should be appreciated that Figure 7A Only a small portion of the image sensor shown in FIG is shown as being utilized, demonstrating the feasibility of using more than two channels as desired according to the techniques described herein. For example, in some embodiments, up to 6 channels, 8 channels, or 10 channels may be used. The intensity of the interferogram signal may be extracted from the captured image sensor signal into the interferogram signal, as shown in FIG. Figure 7B As described above, the pressure sensed by the corresponding sensor can be determined based at least in part on the extracted interferogram signal.

[0054] Figure 8 A portable ventricular assist system 800 is schematically illustrated in accordance with some embodiments. The portable ventricular assist system 800 can include a heart pump 810 and a hardware controller 820 coupled to the heart pump 810 via a connector 830. As described herein, the connector 830 can be configured to include one or more optical connections (e.g., multiple optical connections with different parameters) and one or more electrical connections configured to transmit optical and electrical signals, respectively, between the hardware controller 820 and the heart pump 810 during operation. Although shown as only a single connector 830, it should be understood that in some embodiments, multiple connectors 830 can be used to couple the heart pump 810 and the hardware controller 820.

[0055] like Figure 8 , heart pump 810 may include a rotor 812 and a motor 814 configured to drive rotation of rotor 812 according to one or more operating parameters received from hardware controller 820 via connector 830. Heart pump 810 may further include first and second optical pressure sensors 816, 818, respectively, configured to sense a first pressure signal in, for example, the patient's aorta and a second pressure signal in the patient's left ventricle.

[0056] The hardware controller 820 may include an LED 822 configured to provide light to the first optical pressure sensor 816 and the second optical pressure sensor 818 via one or more optical fibers at least partially disposed within the connector 830. The hardware controller 820 may further include a hardware processor 824 coupled to the heart pump 810 via the connector 830. The hardware processor 824 may be configured to control one or more operations of the heart pump 810 (e.g., pump speed) and receive information about one or more operating parameters of the heart pump 810 during operation. Examples of such information of one or more operating parameters are described herein. The hardware controller 820 may further include a primary power supply 826 and an auxiliary power supply 828 configured to provide power to components of the heart pump 810 (e.g., the motor 814) via the switch 840 and the connector 830. As will be appreciated, although shown as having two power supplies, in some embodiments, the hardware controller may include only a single (e.g., primary) power supply. As described herein, the power provided by the hardware controller 820 to the heart pump 810 can be switched from the primary power source 826 to the auxiliary power source 828 (or vice versa) as needed to ensure continuous and safe operation of the heart pump 810. In some embodiments, the switching from the primary power source 826 to the auxiliary power source 828 (or vice versa) can be performed in response to a signal from the hardware processor 824, which can be configured to monitor the charge levels of the primary power source 826 and the auxiliary power source 828. In some embodiments, the hardware controller 820 can further include a communication circuitry 850 configured to provide information to a computing device (e.g., a smartphone, laptop, tablet computer) for display. In some embodiments, the communication circuitry 850 can be configured, at least in part, as a programming interface to enable programming of the heart pump operating parameters set by the hardware processor 824.

[0057] Therefore, in the case of describing several aspects and embodiments of the technology described in this disclosure, it should be understood that those skilled in the art will easily think of various changes, modifications and improvements. Such changes, modifications and improvements are expected to fall within the spirit and scope of the technology described herein. For example, a person of ordinary skill in the art will easily envision various other components and / or structures for performing functions and / or obtaining results and / or one or more of the advantages described herein, and each of such changes and / or modifications is considered to fall within the scope of the embodiments described herein. Those skilled in the art will recognize or be able to determine many equivalents of the specific embodiments described herein using only routine experiments. Therefore, it should be understood that the above embodiments are presented only by way of example, and within the scope of the appended claims and their equivalents, the invention embodiments can be practiced in a manner other than the specifically described manner. In addition, if two or more features, systems, objects, materials, kits and / or methods described herein do not contradict each other, then any combination of such features, systems, objects, materials, kits and / or methods is included within the scope of this disclosure.

[0058] The embodiments described above can be implemented in any of many ways. One or more aspects and embodiments of the present disclosure relating to the performance of a process or method can utilize program instructions that can be executed by a device (e.g., a computer, a processor, or other device) to perform the process or method or control the performance of the process or method. In this regard, various inventive concepts can be embodied as a computer-readable storage medium (or multiple computer-readable storage media) (e.g., a computer memory, one or more floppy disks, optical disks, optical optical disks, magnetic tapes, flash memory, a circuit configuration in a field programmable gate array or other semiconductor device, or other tangible computer storage media) encoded using one or more processes, which, when executed on one or more computers or other processors, perform one or more methods implementing one or more of the various embodiments described above. The computer-readable medium can be transportable so that the process stored thereon can be loaded onto one or more different computers or other processors to implement the various aspects described above. In some embodiments, the computer-readable medium can be a non-transitory medium.

[0059] The above-described embodiments of the present technology can be implemented in any of many ways. For example, the embodiments can be implemented using hardware, software, or a combination thereof. When implemented in software, the software program code can be executed on any suitable processor or set of processors, regardless of whether it is provided in a single computer or distributed among multiple computers. It should be understood that any component or set of components that performs the functions described above can be generally regarded as a controller that controls the functions described above. The controller can be implemented in many ways, such as with dedicated hardware, or with general-purpose hardware (e.g., one or more processors) that is programmed using microcode or software to perform the functions described above, and can be implemented in combination in a manner when the controller corresponds to multiple components of the system.

[0060] Furthermore, it should be appreciated that a computer may be embodied in any of a variety of forms, such as, by way of non-limiting example, a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer. Furthermore, a computer may be embedded in a device not generally regarded as a computer but having suitable processing capabilities, including a personal digital assistant (PDA), a smart phone, or any other suitable portable or fixed electronic device.

[0061] Furthermore, a computer may have one or more input and output devices. These devices may be used, among other things, to present a user interface. Examples of output devices that can be used to provide a user interface include a printer or display screen for visual presentation of output and a speaker or other sound-generating device for auditory presentation of output. Examples of input devices that can be used for a user interface include a keyboard and a pointing device, such as a mouse, touchpad, and digitizing tablet. As another example, a computer may receive input information through speech recognition or in other audible formats.

[0062] Such computers may be interconnected by one or more networks in any suitable form, including local or wide area networks, such as intranets and intelligent networks (INs) or the Internet. Such networks may be based on any suitable technology and may operate according to any suitable protocol, and may include wireless networks, wired networks, or fiber optic networks.

[0063] Also, as described, some aspects may be embodied as one or more methods. The acts performed as part of the method may be ordered in any suitable manner. Thus, embodiments may be constructed in which acts are performed in an order different from that illustrated, which may include performing some acts simultaneously, even though the acts are shown as sequential acts in illustrative embodiments.

[0064] As defined and used herein, all definitions should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0065] As used herein in the specification and claims, the indefinite articles "a" and "an" should be understood to mean "at least one" unless explicitly indicated to the contrary.

[0066] As used herein in the specification and claims, the phrase "and / or" should be understood to mean "either or both" of the combined elements, i.e., elements that are presented in combination in some cases and separately in other cases. Multiple elements listed using "and / or" should be interpreted in the same manner, i.e., "one or more" of the combined elements. Other elements may optionally be present in addition to the elements specifically identified by the "and / or" clause, whether related or unrelated to those specifically identified elements. Thus, by way of non-limiting example, a reference to "A and / or B," when used with an open-ended term such as "comprising," may mean: in one embodiment, only A (optionally including elements other than B); in another embodiment, only B (optionally including elements other than A); in yet another embodiment, both A and B (optionally including other elements); etc.

[0067] As used herein in the specification and claims, the phrase "at least one" referring to a list of one or more elements should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but does not necessarily include at least one of each element specifically listed in the list of elements and does not exclude any combination of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified in the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified. Thus, by way of non-limiting example, “at least one of A and B” (or equivalently, “at least one of A or B”, or equivalently, “at least one of A and / or B”) may, in an embodiment, refer to at least one (optionally including more than one) A, but no B (and optionally including elements other than B); in another embodiment, may refer to at least one (optionally including more than one) B, but no A (and optionally including elements other than A); in yet another embodiment, may refer to at least one (optionally including more than one) A and at least one (optionally including more than one) B (and optionally including other elements); etc.

[0068] Again, the phrases and terms used herein are for descriptive purposes and should not be considered limiting. The use of "include," "comprising," or "having," "containing," "involving," and variations thereof herein is meant to encompass the items listed thereafter and their equivalents as well as additional items.

[0069] In the claims and the foregoing description, all transitional phrases (e.g., "comprises," "comprising," "carrying," "having," "containing," "involving," "having," "consisting of," and the like) are to be construed as open-ended, i.e., meaning "including, but not limited to." Only the transitional phrases "consisting of" and "consisting essentially of" are to be considered closed or semi-closed transitional phrases, respectively.

[0070] The use of ordinal terms (e.g., "first," "second," "third," etc.) in the claims to modify claim elements does not in itself imply any priority, precedence, or order of precedence over one claim element over another or the temporal order in which the acts of a method may be performed, but serves solely as a marker to distinguish one claim element having a particular name from another claim element having the same name (but using an ordinal term) to distinguish the claim elements.

Claims

1. A portable ventricular assist system comprising: A heart pump comprising: rotor; a motor configured to drive rotation of the rotor at one or more speeds; a first optical pressure sensor configured to detect a first pressure signal; a second optical pressure sensor configured to detect a second pressure signal; and At least one hardware controller comprising: Main power supply; Auxiliary power supply; At least one light emitting diode (LED) that: coupled to the first optical pressure sensor via at least one first optical fiber, and coupled to the second optical pressure sensor via at least one second optical fiber; and At least one hardware processor is configured to determine a differential pressure based at least in part on the first pressure signal and the second pressure signal.

2. The portable ventricular assist system of claim 1 , further comprising a connector configured to connect the heart pump to the at least one hardware controller, the connector comprising at least one electrical connection connecting the primary power source and / or the auxiliary power source to the electric machine; and The at least one LED is connected to at least one optical connection of the first optical pressure sensor and the second optical pressure sensor.

3. The portable ventricular assist system of claim 1 , wherein the at least one hardware controller further comprises a bus system configured to manage power supplied to the motor by the primary power source and / or the auxiliary power source.

4. The portable ventricular assist system of claim 3, wherein the bus system is configured to automatically switch power provided from the primary power source to the auxiliary power source when a state of charge is less than a threshold amount.

5. The portable ventricular assist system of claim 1, further comprising at least one indicator LED configured to indicate a current charge status of the primary power source and / or the auxiliary power source.

6. The portable ventricular assist system according to claim 1, further comprising: Communications circuitry configured to provide information to a computing device for display, the information including one or more quantities associated with operation of the heart pump.

7. The portable ventricular assist system of claim 6, wherein the one or more quantities include an amount of motor current associated with operation of the heart pump.

8. The portable ventricular assist system of claim 6, wherein the one or more quantities comprise one or more physiological quantities associated with the patient when the heart pump is in operation.

9. The portable ventricular assist system of claim 8, wherein the one or more physiological quantities include a differential pressure measurement across the patient's aortic valve.

10. The portable ventricular assist system of claim 6, wherein the communication circuitry is configured to provide the information to the computing device wirelessly.

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