Determination of cardiac parameters for regulating blood pump support

Abstract

The systems, devices, and methods presented herein use a blood pump to obtain measurements of cardiac function. The system can quantify the operation of the natural heart by measuring certain parameters / signals (such as aortic pressure or motor current), and then calculate and display one or more cardiac parameters and cardiac function parameters (such as left ventricular pressure, left ventricular end-diastolic pressure, or cardiac power output). These parameters provide the user with valuable information about current cardiac function and the positioning and function of the blood pump. In some embodiments, the system can serve as a diagnostic and therapeutic tool. Providing cardiac parameters in real time together with warnings about adverse effects and recommendations to support cardiac function (such as increasing or decreasing the volume flow rate of blood pumped by the device), administering medication, and / or repositioning the blood pump allows clinicians to better support and treat cardiovascular disease.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Application No. 62 / 517,668, filed on June 9, 2017, entitled “Determination of Cardiac Parameters for Adjusting Blood Pump Support,” and U.S. Provisional Application No. 62 / 635,662, filed on February 27, 2018, entitled “Determination of Cardiac Parameters for Adjusting Blood Pump Support,” the contents of each of which are incorporated herein by reference in their entirety. Background Art

[0003] Intravascular blood pumps provide hemodynamic support and promote cardiac recovery. Intravascular blood pumps are inserted into the heart and work in parallel with the native heart to supplement cardiac output to provide supplemental cardiac support to patients with cardiovascular disease. An example of such a device is the IMPELLA® series of devices (Abiomed, Danvers, Massachusetts).

[0004] Currently, it is difficult for clinicians to directly and quantitatively determine the amount of support a device should deliver or when to terminate the use of a heart assist device. Consequently, clinicians tend to rely on qualitative judgments and indirect estimates of cardiac function (such as using a fluid-filled catheter to measure intracardiac or intravascular pressure). Traditionally, left ventricular pressure (LVP) is estimated by measuring the pulmonary artery wedge pressure (PAWP) or the pulmonary capillary wedge pressure (PCWP), where a balloon-containing pulmonary catheter is inserted into a branch of the pulmonary artery. PAWP and PCWP are not valid measures of cardiac health because pulmonary artery catheters are intermittent, indirect, and inconsistent, resulting in erroneous data that cannot be reliably used by clinicians to make clinical decisions about the level of cardiac support required for a patient.

[0005] A blood pump provides supplemental cardiac support by assisting in pumping blood through the chambers of the heart, such as from the left ventricle or left atrium into the aorta and from the right atrium or right ventricle into the pulmonary artery. A blood pump is typically inserted to assist in cardiac support for a certain period of time, after which the patient is weaned from the blood pump support, allowing the heart to pump blood without support. Because clinicians do not have access to reliable information about cardiac function, patients are often weaned off too early and too quickly, causing unnecessary strain on the heart.

[0006] Accurate measurement of left ventricular pressure, cardiac power output, and other cardiac variables can allow clinicians to make better clinical decisions for their patients based on the heart's current needs.Therefore, there has long been a need to improve current systems that provide clinicians with information about cardiac support and heart health. Summary of the Invention

[0007] In some embodiments, a method for providing cardiac support to a heart includes operating a blood pump positioned in the heart, the blood pump having a cannula, a motor, the motor operating at a motor speed and drawing a variable current to provide a level of cardiac support to the heart. The blood pump also includes a controller coupled to the blood pump. The method also includes the controller measuring aortic pressure, measuring motor current and motor speed, determining a pressure gradient across the cannula associated with the motor current and motor speed, and using a processor to calculate a calculated cardiac parameter (e.g., left ventricular pressure (LVP) or left ventricular end-diastolic pressure (LVEDP)) based on the aortic pressure and the pressure gradient across the cannula associated with the motor current and motor speed. The method also includes recording the calculated cardiac parameter in a memory and using the calculated cardiac parameter to determine a cardiac function parameter (e.g., a measure of cardiac power output). The method continues by determining a recommended change to the support provided by the blood pump based on the cardiac function parameter and the calculated cardiac parameter; and generating the recommended change to the support for display. Recommended changes to support can be, for example, recommendations to increase or decrease motor speed during disengagement, recommendations to adjust the positioning of the blood pump in response to a suction event, or recommendations to change to a different blood pump with different capabilities, among other recommendations. The method can also include generating cardiac function parameters and the calculated cardiac parameters for display. Displaying important cardiac parameters and cardiac function parameters allows a healthcare professional to make informed decisions about adjustments to the patient's blood pump support. In addition, calculating these parameters based on the motor current and motor speed of the blood pump and the measured aortic pressure enables determination of recommendations for adjustments and adjustments to the blood pump, which can be provided to the healthcare professional to help identify possible problems and prompt adjustments in care. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The foregoing and other objects and advantages will become apparent upon consideration of the following detailed description taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:

[0009] Figure 1 An intravascular cardiac pump system located in the heart is shown;

[0010] Figure 2A An example graph showing motor current versus pressure gradient is shown;

[0011] Figure 2B Example graphs showing measured aortic pressure and calculated LVP as a function of time;

[0012] Figure 2CExample graphs showing LVP waveforms and aortic pressure waveforms as a function of time;

[0013] Figure 2D An example graph showing a time-based first derivative of an LVP waveform as a function of time;

[0014] Figure 2E An example graph showing a time-based second derivative of an LVP waveform as a function of time;

[0015] Figure 3 An exemplary user interface for a heart pump controller displaying measurements over time is shown;

[0016] Figure 4 A process for optimizing the performance of a blood pump in a heart based on measured and calculated heart parameters is shown;

[0017] Figure 5A An exemplary user interface for a heart pump controller illustrating intermittent pumping events at a blood pump is shown;

[0018] Figure 5B An exemplary user interface for a heart pump controller illustrating successive pumping events at a blood pump is shown;

[0019] Figure 5C an exemplary user interface for a heart pump controller showing a graphical metric trend screen;

[0020] Figure 5D shows an exemplary user interface for a heart pump controller illustrating changes in heart function during weaning as captured by displayed indicators;

[0021] Figure 6 A process for determining cardiac power output and displaying a recommendation to a user for adjustments to pump support is shown;

[0022] Figure 7 A process for recommending adjustments to motor speed based on measured and calculated cardiac parameters is shown;

[0023] Figure 8 A process for recommending adjustments to motor speed based on cardiac power output and LVEDP is shown;

[0024] Figure 9 A process for an apparatus for recommending a higher flow for treatment based on measured and calculated cardiac parameters is shown;

[0025] Figure 10 A process for recommending medication based on measured and calculated cardiac parameters is shown;

[0026] Figure 11 A process for alerting a user of a predicted adverse cardiac event based on measured and calculated cardiac parameters is shown;

[0027] Figure 12 A process for balancing right and left blood pumping devices during biventricular support based on measured and calculated cardiac parameters is shown;

[0028] Figure 13 A process for automatically modifying the level of support provided by a blood pump is shown; and

[0029] Figure 14 A block diagram of an exemplary blood pump system is shown. DETAILED DESCRIPTION

[0030] To provide an overall understanding of the systems, methods, and devices described herein, certain illustrative embodiments will be described. Although the embodiments and features described herein are specifically described for use in conjunction with a percutaneous blood pump system, it will be understood that all of the components and other features outlined below can be combined with one another in any suitable manner and can be adapted and applied to other types of cardiac therapies and cardiac assist devices (including cardiac assist devices implanted using a surgical incision, etc.).

[0031] The systems, devices, and methods described herein provide a mechanism for providing clinicians with cardiac parameters and cardiac function parameters based on motor current, motor speed, and aortic pressure measured at the blood pump system. The functionality and output of the intravascular blood pump, along with the measurable cardiac parameters, can be used to calculate additional parameters useful in determining a patient's cardiac performance and health. By making these determinations and displaying the data to the clinician in a useful and meaningful manner, the clinician has more data available to inform healthcare decisions. The additional cardiac parameters and cardiac function and their trends accessible through algorithms based on the intravascular blood pump output allow clinicians to make informed decisions about the cardiac support provided to a patient by various blood pumps, by positioning the blood pump and administering medications. The algorithms also allow the blood pump system to determine important cardiac parameters and display them to the clinician to inform patient care decisions, or to make recommendations for regulatory support, for example, by displaying recommendations for different levels of cardiac function based on various cardiac parameter inputs.

[0032] Based on knowledge of blood pump operation (e.g., knowledge of the heart's pressure and flow response relative to the blood pump's operating speed and input power), it is possible to calculate a variety of cardiac parameters based on blood pump function. Based on the operational functionality of the pump within the heart, algorithms can be constructed to calculate how cardiac indices change as the blood pump interacts with the cardiac system. By making these determinations and providing clinicians with both immediate and historical cardiac parameters, clinicians are better able to understand and respond to changes in blood pump functionality or a patient's cardiac health.

[0033] In particular, providing accurate and timely cardiac parameters (such as, LVEDP, LVP, aortic pulse pressure, mean aortic pressure, pump flow, pressure gradient, heart rate, cardiac output, cardiac power output, native cardiac output, native cardiac power output, cardiac contractility, cardiac diastole, fluid responsiveness, volume state, cardiac unloading index, cardiac recovery index, left ventricular diastolic function, left ventricular diastolic elastance, left ventricular systolic elastance, stroke volume, heart rate variability, stroke volume variability, pulse pressure variability, aortic compliance, vascular compliance or vascular resistance) to clinicians enables clinicians to make well-known decisions about patient care. Total cardiac output and native cardiac output can both be determined using the methods and systems described herein. Native cardiac output is used in this article to describe the cardiac output of only the heart, without the contribution of the blood pump. Similarly, native cardiac power output is used to describe the cardiac power output of the heart, without any contribution of the blood pump. In contrast, total cardiac output is used in this article to describe the cardiac output produced by the combination of the heart and the blood pump. Similarly, total cardiac power output is used to describe the cardiac power output of the heart (including both the natural power output contributions of the heart and the blood pump). Throughout this application, when determining or calculating cardiac power output or cardiac output, the systems and methods described herein can calculate either total cardiac output or natural cardiac output, and references to cardiac output or cardiac power output can refer to either natural output or total output.

[0034] The algorithms discussed herein enable clinicians to make informed decisions about weaning patients. Clinicians can better determine when it is appropriate to wean a patient off cardiac support provided by a blood pump based on the parameters provided. Furthermore, the algorithms provided herein can enable clinicians to make decisions about the appropriate rate at which to wean a patient off cardiac support by providing recommendations about the level of support, motor speed, and a blood pump suitable for providing the recommended motor speed to support cardiac function.

[0035] The systems, devices, and methods described herein further help optimize the performance of the blood pump by measuring and calculating cardiac parameters. The estimation of LVP and the real-time display of the LVP waveform, along with other cardiac indices, enables the physician to understand the patient's current and historical cardiac function and the level of support provided by the blood pump. The physician uses this information to make modifications to the level of support provided (e.g., weaning the patient off support or increasing the support provided), the positioning and functionality of the blood pump, the determination of the occurrence of aspiration events, and other clinical determinations as described below.

[0036] The systems, devices, and methods described herein enable clinicians to visually determine whether a blood pump is properly positioned in the heart and operating properly. LVP estimation is very sensitive to aspiration events and can be used to inform clinicians about aspiration events and improper positioning and help reposition the pump in the heart. Cardiac indicators determined according to the algorithms described herein and displayed to clinicians can further help identify the cause of aspiration events when they occur.

[0037] In addition, the systems, devices, and methods described herein provide clinicians with data and recommendations for providing additional therapeutic support, such as administering medication to a patient to help restore cardiac function. For example, an algorithm can provide recommendations about which medications may be beneficial and provide dosing information based on cardiac parameters and parameter trends. Trends in cardiac parameters such as native cardiac output, end-diastolic pressure, and cardiac power output can be provided to clinicians, and the algorithm can make recommendations based on the trends for support in titrating inotropes.

[0038] Alternatively, cardiac parameters can be presented to the clinician to help regulate fluid and patient volume status. Native output, end-diastolic pressure, and pulse pressure variation can be provided to the clinician to enable the clinician to determine whether the patient is in the optimal fluid window and to determine the patient's fluid responsiveness. The algorithm can provide the clinician with a notification indicating whether the patient is considered to be in the optimal fluid window based on these parameters and an indication of whether the patient is likely to respond to the administration of fluid.

[0039] The systems, devices, and methods described herein can be used to provide clinicians with warnings about predicted adverse events that are predicted based on measured and calculated cardiac parameters. Patients who rely on blood pump support are at risk for additional ischemic events. Small changes in left ventricular contractility, left ventricular diastolicity, and LVEDP are all early indicators of silent ischemic events. Alerting clinicians about changes in these parameters enables clinicians to detect ischemic events earlier and respond more quickly. In addition, other adverse events and consequences (such as aortic regurgitation and conduction abnormalities (in the case of balloon aortic valvuloplasty (BAV) in preparation for transcatheter aortic valve replacement (TAVR)) require a pacemaker. Changes in left ventricular diastolicity, left ventricular diastolic filling pressure, systolic pressure gradient, and cardiac power and total power can all serve as early indicators of such events and can be calculated and detected by the algorithms described herein and presented to clinicians.

[0040] Finally, the systems, devices, and methods described herein can be used to balance a right-sided device and a left-sided device used simultaneously, for example, to provide biventricular support. Balancing the two devices can present unique challenges: balancing the right and left-sided devices to maintain appropriate pressures in the lungs and limit the risk of pulmonary edema. By measuring native and total output along with pulmonary artery pressure and left ventricular diastolic pressure, an algorithm can provide information about these parameters to the clinician to help inform decisions about the operation of the biventricular device and can provide recommendations to help the clinician balance the two devices.

[0041] The systems, devices, and methods presented herein describe mechanisms for measuring various cardiac parameters and cardiac function parameters useful to clinicians in the care and treatment of patients being treated with cardiac support using a blood pump based on blood pump output and a measured pressure signal in a blood pump system. As described below, the parameters and recommendations provided by the algorithm can be used by clinicians to inform various medical treatment decisions.

[0042] Figure 1An exemplary prior art heart assist device is shown positioned in a heart 102. Heart 102 includes a left ventricle 103, an aorta 104, and an aortic valve 105. An intravascular heart pump system includes a catheter 106, a motor 108, a pump outlet 110, a cannula 111, a pump inlet 114, and a pressure sensor 112. Motor 108 is coupled to catheter 106 at its proximal end and to cannula 111 at its distal end. Motor 108 also drives a rotor (not visible in the figure) that rotates to pump blood from pump inlet 114 through cannula 111 to pump outlet 110. Cannula 111 is positioned across aortic valve 105 so that pump inlet 114 is within left ventricle 103 and pump outlet 110 is within aorta 104. This configuration allows intravascular heart pump system 100 to pump blood from left ventricle 103 into aorta 104 to support cardiac output.

[0043] The intravascular heart pump system 100 pumps blood from the left ventricle into the aorta in parallel with the natural cardiac output of the heart 102. Blood flow through a healthy heart is typically about 5 liters / minute, and blood flow through the intravascular heart pump system 100 can be at similar or different flow rates. For example, the flow rate through the intravascular heart pump system 100 can be 0.5 liters / minute, 1 liter / minute, 1.5 liters per minute, 2 liters / minute, 2.5 liters / minute, 3 liters / minute, 3.5 liters / minute, 4 liters / minute, 4.5 liters / minute, 5 liters / minute, greater than 5 liters / minute, or any other suitable flow rate.

[0044] The motor 108 of the intravascular heart pump system 100 can be varied in any number of ways. For example, the motor 108 can be an electric motor. The motor 108 can be operated at a constant rotational speed to pump blood from the left ventricle 103 to the aorta 104. Operating the motor 108 at a constant speed generally requires supplying a varying amount of current to the motor 108 because the load on the motor 108 varies during different phases of the heart's 102 cardiac cycle. For example, as the mass flow rate of blood entering the aorta 104 through the blood pump increases (e.g., during systole), the current required to operate the motor 108 increases. As will be discussed further with respect to the following figures, such changes in motor current can thus be used to help characterize cardiac function. Using motor current to detect mass flow rate can be facilitated by the position of the motor 108, which is aligned with the natural direction of blood flow from the left ventricle 103 into the aorta 104. Using motor current to detect mass flow rate can also be facilitated by the small size and / or low torque of the motor 108. Figure 1The motor 108 has a diameter of approximately 4 mm, but any suitable motor diameter may be used as long as the rotor-motor mass is small enough, has low enough torque, and is positioned so that it can quickly and easily respond to changes in the physiological pressure gradient across the pump. In some embodiments, the motor 108 has a diameter of less than 4 mm.

[0045] In some embodiments, one or more motor parameters other than current are measured (such as power delivered to the motor 108). Figure 1 The motor 108 in the embodiment is operated at a constant speed. In certain embodiments, the speed of the motor 108 is varied over time (e.g., as a delta function, a step function, a sine function, or a ramp function) to detect native heart function. In some embodiments, the motor 108 can be located outside the patient's body and can drive the rotor via an elongated mechanical transmission element (e.g., a flexible drive shaft, a drive cable, or a fluid coupling).

[0046] The pressure sensor 112 of the intravascular heart pump system 100 can be disposed at various locations on the pump, such as on the motor 108 or at the outflow portion of the pump (i.e., the pump outlet 110). When the intravascular blood pump system 100 is positioned across the aortic valve 105, placing the pressure sensor 112 at the pump outlet 110 enables the pressure sensor 112 to measure the true aortic pressure (AoP). In certain embodiments, the pressure sensor 112 of the intravascular heart pump system 100 can be disposed on the cannula 111, on the catheter 106, or at any other suitable location. When the intravascular heart pump system 100 is properly positioned in the heart 102, the pressure sensor 112 can detect the blood pressure in the aorta 104. The blood pressure information can be used to properly position the intravascular heart pump system 100 in the heart 102. For example, the pressure sensor 112 can be used to detect whether the pump outlet has passed through the aortic valve 105 into the left ventricle 103, which would circulate blood only within the left ventricle 103 rather than transporting blood from the left ventricle 103 to the aorta 104. In some embodiments, the pressure sensor 112 is a fluid-filled tube, a differential pressure sensor, a hydraulic pressure sensor, a piezoresistive strain gauge, an optical interferometry sensor or other optical sensor, a MEMS piezoelectric sensor, or any other suitable sensor.

[0047] The intravascular heart pump system 100 can be inserted into the heart 102 in a variety of ways, such as by percutaneous insertion. For example, the intravascular heart pump system can be inserted through the femoral artery (not shown), through the aorta 104, across the aortic valve 105, and into the left ventricle 103. In some embodiments, the intravascular heart pump system 100 is surgically inserted into the heart 102. In some embodiments, the intravascular heart pump system 100 or a similar system adapted for the right heart is inserted into the right heart. For example, a right heart pump similar to the intravascular heart pump system 100 can be inserted through the femoral vein and into the inferior vena cava, bypassing the right atrium and right ventricle, and extending into the pulmonary artery. Alternatively, a right heart pump can be inserted through the internal jugular vein and superior vena cava, and a left heart pump can be inserted through the axillary artery. In some embodiments, the intravascular heart pump system 100 can be positioned for operation in the vascular system outside the heart 102 (e.g., in the aorta 104). The intravascular heart pump system 100 is sensitive enough to allow characterization of native heart function by residing minimally invasively within the vascular system.

[0048] Figure 2A An example graph of motor current versus pressure gradient is shown. Graph 200 has an x-axis 202 representing motor current in mA and a y-axis 204 representing pressure gradient (dP) in mmHg. Graph 200 includes a trendline 206 illustrating the relationship between motor current and pressure gradient. At a known motor speed, the motor current drawn by the blood pump is proportional to the pressure gradient across the blood pump cannula. Graph 200 can serve as a lookup table for an algorithm used to determine the pressure gradient based on a given motor current and motor speed at which the blood pump motor is currently operating. For example, a motor current of approximately 650 mA, indicated by point 208 on the x-axis, corresponds to a pressure gradient of 120 mmHg, indicated by point 210 on the y-axis, as determined by extending a line from the motor current at point 208 upward to trendline 206, and then extending the line from the intersection with trendline 206 at point 210 to the y-axis. The relationship between motor current and pressure gradient described by graph 200 may be determined in the laboratory under physiological conditions for a particular blood pump and may be stored in the memory of a processor within a blood pump controller.

[0049] The controller determines the pressure gradient associated with the motor current and motor speed at which the blood pump is currently operating by accessing the graph 200. The controller can then compare the pressure gradient with other determined or measured values, such as at a pressure sensor (e.g., Figure 1The aortic pressure measured at the pressure sensor 112 in the heart is used together to determine various cardiac parameters such as LVEDP, LVP, aortic pulse pressure, mean aortic pressure, pump flow, pressure gradient, heart rate, cardiac output, cardiac power output, native cardiac output, native cardiac power output, cardiac contractility, cardiac relaxation, fluid responsiveness, volume status, cardiac unloading index, and cardiac recovery index.

[0050] For example, once the pressure gradient across the blood pump cannula has been determined based on the motor current and motor speed, the pressure gradient across the blood pump cannula can be used together with the measured aortic pressure (such as the pressure measured at pressure sensor 112) to determine an estimate of LVP at the inlet cage of the pump. LVP is estimated by subtracting the pressure gradient from the aortic pressure. As described below with respect to Figure 2B As described, the LVP determined in this manner is a very good estimate of the actual LVP in the heart. The estimated LVP can be displayed by the controller on a display screen where it can be accessed and viewed by a clinician. The clinician can use the information provided by the LVP at a given moment or a historical view of changes in the LVP to make clinical decisions about the patient's treatment (including making informed decisions about changes to the support provided by the blood pump).

[0051] Although the relationship between the pressure gradient and the motor current of the blood pump at a known motor speed is depicted as graph 200, the controller can use the information contained in graph 200 by accessing a lookup table or by querying a function that describes the relationship between the pressure gradient and the motor current and motor speed. In some embodiments, the controller can consider additional parameters other than motor current and motor speed in determining the pressure gradient across the cannula of the blood pump, such as other properties of the pump, properties of the pump controller or console, environmental parameters, and motor speed settings. Considering additional parameters in the function used to determine the pressure gradient can result in a more accurate correlation between the motor current and the pressure difference, thereby allowing for more accurate calculation of LVP or other cardiac parameters.

[0052] Figure 2BAn example graph of measured aortic pressure and calculated LVP as a function of time is shown. Graph 201 has an x-axis 203 representing time in seconds and a y-axis 205 representing head pressure in mmHg. The graph has three traces including aortic pressure 212, estimated LVP 214 (dashed line), and actual measured LVP 216. The traces on graph 201 illustrate that the estimated LVP determined based on the measured aortic pressure and the determined pressure gradient across the blood pump cannula agrees with the measured LVP values. The algorithm determines continuous LVP (including full waveform and LVEDP points) within the cardiac cycle based on the motor current and the measured aortic pressure. The algorithm measures LVP immediately inside the pump inlet 114, enabling the algorithm to determine pumping events and distinguish between systole / continuous pumping and diastole / intermittent pumping.

[0053] The LVEDP point in the cardiac cycle is important in the calculation of other cardiac parameters. The pressure at the end-diastolic point is the LVP immediately prior to left ventricular contraction, which can be defined by the occurrence of the R wave in the reference EKG measurement. The LVEDP point in the cardiac cycle can be estimated based on the aortic pressure 212 placement signal, the LVP 214 waveform, and the pressure gradient at the pump. In some embodiments, the LVEDP is estimated based on the identification of a peak in the estimated LVP 214 waveform, which is then shifted on the time axis to estimate the LVEDP point. This technique is known as peak detection and time indexing. In an alternative embodiment, the estimated LVEDP is calculated based on the time-based first and / or second derivatives of the estimated LVP 214 waveform over time.

[0054] Figure 2C An example graph 220 of the aortic pressure 212 waveform and the estimated LVP 214 waveform relative to time is shown. The graph has an x-axis 222 representing time and a y-axis 224 representing pressure head in mmHg. The graph includes a trace of the estimated LVP waveform 226 (dashed line) and a trace of the aortic pressure 228 (solid line). In some embodiments, an LVEDP can be selected based on the graph 220 by selecting the peak of the estimated LVP waveform 226 and shifting the time point. Although only one LVEDP point 229 is shown in the graph 220 for convenience, the LVEDP can be calculated for each cycle of the LVP waveform to monitor changes over time.

[0055] Figure 2DAn example graph 230 of the estimated first derivative of the LVP 214 waveform versus time is shown. Graph 230 can be calculated as the derivative of the LVP waveform 226 in graph 220. Graph 230 has an x-axis 232 representing time and a y-axis 234 representing the first derivative of pressure with respect to time (dP / dt) in mmHg / sec. The graph includes a trace of the first derivative of the LVP waveform 236 and an indication of an LVEDP point 238 that can be selected as the estimated LVEDP based on the trace of the first derivative of the LVP waveform 236. Point 238 illustrates a point associated with the LVEDP, which can be calculated as, for example, a point in time where the first derivative of the LVP waveform 236 is midway between a minimum valley and a maximum peak. Although only one LVEDP point 238 is shown in graph 230 for convenience, the LVEDP can be calculated for each cycle of the LVP waveform. Alternatively, a graph 230 of the first derivative of the LVP waveform 236 may be useful in "windowing" or narrowing the search for the LVEDP point 238, which may then be determined based on a graph of second derivatives or other means. The estimate of the LVEDP point 238 based on the graph 230 may be sensitive to the sampling frequency at higher sampling frequencies, such that higher sampling results in a more accurate calculation of the LVEDP point 238.

[0056] Figure 2E An example graph 240 of the estimated second derivative of the LVP 214 waveform versus time is shown. Graph 230 may be calculated as the derivative of the LVP waveform 236 in graph 230 or the second derivative of the LVP waveform 226 in graph 220. Graph 240 has an x-axis 242 representing time and an x-axis 243 representing pressure versus time in mmHg / sec. 2 The second derivative of unity (d 2 P / dt 2 ). The graph includes a trace of the second-order derivative of the LVP waveform 246 and an indication of an LVEDP point 248 that can be selected as an estimated LVEDP based on the trace of the second-order derivative of the LVP waveform 246. Point 248 illustrates a point associated with the LVEDP, which can be calculated, for example, as the point at which the second-order derivative of the estimated LVP waveform 246 has a maximum peak. Although only one LVEDP point 248 is shown in the graph 240 for convenience, the LVEDP can be calculated for each cycle of the LVP waveform. Similar to the estimation of the LVEDP point 238 based on the first-order derivative graph 230, the estimation of the LVEDP point 248 based on the second-order derivative graph 240 can be sensitive to the sampling frequency and more accurate at high sampling frequencies.

[0057] The peaks of the first or second time derivatives of the LVP waveform can be used to accurately calculate the LVEDP point. In addition, the peaks and valleys of the first and second time derivatives of the LVP waveform can be used to narrow the search window for a given LVEDP point and thereby improve the detection of the LVEDP point, thereby reducing false positives. Using the time-based first or second derivatives of the measured aortic pressure 212 to determine the LVEDP enables the algorithm to more accurately determine the LVEDP point in the cardiac cycle. Alternatively, the aortic pressure waveform (e.g., Figure 2B 212) can be similarly used together with the first and second derivatives of the aortic pressure waveform to determine the LVEDP point.

[0058] Figure 3 An exemplary user interface for a heart pump controller showing a waveform of heart function over time is shown. User interface 300 may be used to control Figure 1 The user interface 300 includes a pressure signal waveform 302, an LVP waveform 303, and a motor current waveform 304, a flow rate 306, a measure of cardiac power output 308, and a measure of native cardiac output 310. The pressure signal waveform 302 indicates the pressure measured by the pressure sensor of the blood pump (e.g., pressure sensor 112), and when the pump is properly placed, the pressure signal waveform 302 corresponds to the aortic pressure. The pressure signal waveform 302 and the LVP waveform 303 can be used by a health care professional to adjust the position of an intravascular heart pump (such as, Figure 1 The intravascular heart pump 100 in FIG. 3 is properly placed in the heart. The pressure signal waveform 302 is used to verify the placement of the intravascular heart pump by evaluating whether the waveform 302 is an aortic waveform or a ventricular waveform. An aortic waveform indicates that the intravascular heart pump motor is located in the aorta. A ventricular waveform indicates that the intravascular heart pump motor has been inserted into the incorrect position in the ventricle. A scale 312 for the placement signal waveform is displayed to the left of the waveform. The default scale is 0-160 mmHg. The default scale can be adjusted in 20 mmHg increments, for example, scale 312 displays a scale from -20-160 mmHg. To the right of the waveform is a display 314, which labels the waveform, provides units of measurement, and includes an indication of the current estimated pressure. Display 314 may also include estimates of aortic pressure 316 and / or LVP 318, which may be instantaneous estimates, averages, or maximum or minimum values, as well as indications of other cardiac parameters calculated from the pressure signal waveform (such as LVEDP). In some embodiments, the display 314 shows the maximum and minimum values ​​and the average value from the calculated cardiac indices. By including the pressure signal waveform 302, the LVP waveform 303 and the display 314, the pressure signal and LVP are displayed as a function of time, and important cardiac parameters are extracted and displayed in the display 314.

[0059] In some embodiments, variability between different blood pumps is accounted for by calibrating the LVP waveform 303 to the measured aortic pressure waveform 302. The user may be prompted by the display to manually adjust the estimated LVP waveform peak along the y-axis (e.g., Figure 2B 214) to match the peak of the aortic pressure waveform (e.g., Figure 2B 212 in the figure). In some embodiments, calibration is automated for the user based on the pressure readings of the aortic pressure and the LVP waveform. In other embodiments, the required calibration can be calculated by a controller in the user interface 300, and a prompt can be presented to the user with instructions to align the peak of the LVP waveform during systole with the same peak in the aortic pressure waveform (including a suggested value based on the controller's calculation of the same alignment in the context of the program). By calculating the alignment in this context, the controller can also detect the precise points in the cardiac cycle where the aortic pressure waveform and the LVP waveform should overlap. The overlap of the aortic pressure waveform and the LVP waveform corresponds to the opening and closing of the aortic valve. These events mark the beginning and end of systole. Determination of the overlap point between the aortic pressure waveform and the LVP waveform is difficult to perform by eye, but can be calibrated by the controller to improve the calibration required to identify the peaks of the LVP waveform and the aortic pressure waveform.

[0060] Automating the calibration procedure simplifies the use of the user interface 300 and ensures that appropriate calibration values ​​are presented to the user.The calibration calculations can be further improved at high sampling frequencies.

[0061] The motor current waveform 304 is a measure of the energy intake of the heart pump's motor. The energy intake varies with the motor speed and the pressure difference between the inlet and outlet regions of the cannula, resulting in a variable volume load on the rotor. When used with an intravascular heart pump such as Figure 1When used with an intravascular heart pump 100 in a conventional catheter, the motor current provides information about the position of the catheter relative to the aortic valve. When the intravascular heart pump is correctly positioned (with the inlet region in the ventricle and the outlet region in the aorta), the motor current is pulsatile because the mass flow rate through the heart pump varies with the cardiac cycle. When the inlet and outlet regions are on the same side of the aortic valve, the motor current will decay or be flat because the pump's inlet and outlet are in the same chamber and there is no variability in differential pressure, resulting in a constant mass flow rate and, subsequently, a constant motor current. A scale 320 for the motor current waveform is displayed to the left of the waveform. The default scaling is 0-1000 mA. The scaling can be adjusted in increments of 100 mA. To the right of the waveform is a display 322 that labels the waveform, provides the units of measurement, and shows the maximum, minimum, and average values ​​from the received samples. Although pressure sensors and motor current sensors may not be required to position a surgically implanted pump, the sensors can be used in such a device to determine additional characteristics of native heart function to monitor therapy.

[0062] Although Figure 3 Only three waveforms (pressure signal waveform 302, LVP waveform 303, and motor current waveform 304) are shown in FIG3 , but additional waveforms may be displayed on the main screen of display 300 or accessible on additional screens. For example, a systolic waveform, a heart state waveform, an ECG waveform, or any other appropriate heart parameter that changes over time or pulse may be displayed on display 300. Displaying heart information as a trend line allows a physician to review a patient's historical heart status and make decisions based on visible trends. For example, a physician may observe a decrease or increase in aortic pressure over time, as shown in pressure signal waveform 302, and decide to modify or continue treatment based on this observation.

[0063] Figure 3The position, depiction, and identification and number of indicators on the controller in the are intended to be illustrative. The number of indicators and indicators, the position of the same indicators and indicators on the console, and the indicators displayed may be different from those shown here. The cardiac parameters displayed to the user may be, for example, LVEDP, LVP, aortic pulse pressure, mean aortic pressure, pump flow, pressure gradient, heart rate, cardiac output, cardiac power output, native cardiac output, native cardiac power output, cardiac contractility, cardiac diastolicity, fluid responsiveness, volume state, cardiac unloading index, cardiac recovery index, left ventricular diastolic function, left ventricular diastolic elastance, left ventricular systolic elastance, stroke volume, heart rate variability, stroke volume variability, pulse pressure variability, aortic compliance, vascular compliance, or vascular resistance. In some embodiments, the font, font size, layout, and positioning of the data displayed to the user can be configured to be easy to use in a critical care scenario.

[0064] The measurement of native cardiac output 310 includes a display of NCO in L / min calculated based on the measured cardiac parameters. Native cardiac output is a measure of the blood flow attributable to the heart itself or the rate of blood flow in the blood vessels surrounding the blood pump. Native cardiac output is calculated based on the placement signal (aortic pressure) 316 and the pulse pressure calculated at the controller by subtracting the minimum aortic pressure value from the maximum aortic pressure value. The pulse pressure can be calculated periodically by the controller. Native cardiac output can be used to calculate additional cardiac parameters that have clinical relevance. For example, native cardiac output can be combined with information about the flow rate of the blood pump to calculate the total cardiac output of the heart itself and the blood pump.

[0065] The measurement of cardiac power output 308 includes a display of total cardiac power output in watts calculated based on the measured cardiac parameters. Total cardiac power output is calculated based on total cardiac output, which is calculated based on native cardiac output as described above. Total cardiac power output is calculated by multiplying cardiac output by mean arterial pressure and dividing by 451.

[0066] Flow rate 324 can be a target blood flow rate set by the user or an estimated actual flow rate. In some modes of the controller, the controller will automatically adjust the motor speed in response to changes in afterload to maintain the target flow rate. In some embodiments, if flow calculation is not possible, the controller will allow the user to set a fixed motor speed indicated by a speed indicator.

[0067] The memory within the user interface or controller records the data measured, calculated, and displayed on the controller. The memory may have a sampling rate of 25-150 Hz. In some embodiments, a higher sampling rate (such as 100 Hz or greater) is preferred because the data will be recorded in the data log in the memory at a faster rate. The higher fidelity data recorded in the memory can be used to better estimate cardiac function over time. For efficiency, the waveforms, algorithms, and alarms displayed to the user on the user interface can be displayed at a lower rate.

[0068] The display 300 includes various buttons 326-334 for accessing additional display screens. The buttons include a menu button 326, a purge menu button 328, a display button 330, a flow control button 332, and a silent alarm button 334. The buttons shown on the display 300 are intended to be illustrative, and alternative or additional buttons may be accessible to the user. The menu button 326 allows the user to access additional information regarding the use of the display 300 (including software version, registration, and usage date). The menu button 326 also allows the user to access options such as the power mode of the display 300 or to lock the display 300. The menu button 326 also allows the user to calibrate the display 300 or access options or instructions for calibrating the display 300 in conjunction with an attached blood pump. For example, the user can calibrate the measured pressure value or cardiac parameter displayed as a waveform to a known value of the cardiac parameter measured by an arterial catheter or the like. The purge menu button 328 allows the user to access additional usage options, settings, and information related to the purge system of the attached blood pump. A display menu button 330 allows the user to access additional cardiac indices and parameters and, in some cases, add or change the cardiac indices displayed on the main screen of the display 300. A flow control button 332 allows the user to access additional options and settings related to controlling the pump's flow rate by adjusting the pump motor speed. The flow control button allows the user to access recommendations related to the current pump motor speed and various cardiac indices calculated by the controller, and allows the user to enter or accept adjustments to the pump motor speed. A mute alarm button 334 allows the user to mute an alarm or access additional information regarding an alarm or warning issued by the controller. The controller may issue warning notifications to the user regarding the use of the display, the blood pump, and related systems, or cardiac indices calculated by the controller. Warnings and alarms may be audible alarms, pop-up screens on the display 300, or may be sent directly to the clinician, for example, via text, webpage, or email.

[0069] In some embodiments, a warning or alarm is triggered by a cardiac index calculated, measured, or monitored by the controller falling below a set threshold. In some embodiments, a warning or alarm is triggered by a cardiac index calculated, measured, or monitored by the controller exceeding a set threshold. In some embodiments, a warning or alarm is triggered by a change in a cardiac index calculated, measured, or monitored by the controller exceeding a set threshold or falling below a set threshold. In some embodiments, the set threshold is a system value set within the controller. In some embodiments, the set threshold is set by a clinician based on the patient's history and health. In some embodiments, the set threshold is a previous value of the cardiac index (e.g., a previous value measured or calculated a predetermined amount of time ago).

[0070] In some embodiments, the warning or alarm is a recommendation to alter the support provided to the heart by the blood pump based on one or more of the calculated, measured, or monitored cardiac indices. Figure 4-11 Illustrated is a process used by a controller to determine various recommended changes to the cardiac support provided by a blood pump.

[0071] Figure 4 A process 400 is shown for optimizing the performance of a blood pump in a heart based on measured and calculated cardiac parameters.

[0072] In step 402, the motor of the heart pump is operated at a certain rotational speed. In step 404, the aortic pressure is measured. The aortic pressure can be measured by a pressure sensor connected to the heart pump, by a separate catheter, by a non-invasive pressure sensor, or by any other suitable sensor. The pressure sensor can be a fluid-filled tube, a differential pressure sensor, a hydraulic pressure sensor, a piezoresistive strain gauge, an optical interferometry sensor or other optical sensor, a MEMS piezoelectric sensor, or any other suitable sensor. In some embodiments, in addition to or as an alternative to measuring the aortic pressure, the ventricular pressure is also measured. In step 406, the current delivered to the motor is measured, and the motor speed is measured. In step 408, the pressure differential across the cannula of the blood pump is determined based on the measured motor current and motor speed by using a lookup table or accessing a function that takes into account the measured motor current at a known speed and optionally other parameters. In step 410, a cardiac parameter is calculated based on the aortic pressure and the pressure differential across the cannula of the blood pump. The cardiac parameter may be one of LVEDP, LVP, aortic pulse pressure, mean aortic pressure, pump flow, pressure gradient, or heart rate. Each of these cardiac parameters can be used by a clinician as a measure of various aspects of cardiac health and function. Trends in each of the cardiac parameters over time can be used by a clinician to determine whether native cardiac output is improving or decreasing, and clinical decisions about support provided by the blood pump and medication therapy can be made based on these trends. In some embodiments, more than one cardiac parameter is calculated based on aortic pressure and the pressure differential across the cannula of the blood pump.

[0073] In particular, to evaluate the performance of the blood pump within the patient's heart, one or more of LVP and LVEDP may be calculated according to an algorithm. In some embodiments, the calculated metrics are evaluated by a processor to determine if there are any issues with the current performance of the blood pump and to provide recommendations to the user to correct the issues. In some embodiments, the metrics are presented for evaluation by a healthcare professional.

[0074] The calculated cardiac parameters are recorded in memory in step 412. By accessing the recorded cardiac parameters stored in memory, a historical view of the cardiac parameters over time can be accessed by the user or displayed as a trend line on a display console.

[0075] In step 414, cardiac function parameters are determined based on the calculated cardiac parameters. The cardiac function parameters may be any of the following: cardiac output, cardiac power output, native cardiac output, native cardiac power output, cardiac contractility, cardiac diastolicity, fluid responsiveness, volume state, cardiac unloading index, cardiac recovery index, left ventricular diastolic function, left ventricular diastolic elastance, left ventricular systolic elastance, stroke volume, heart rate variability, stroke volume variability, pulse pressure variability, aortic compliance, vascular compliance, or vascular resistance. These cardiac function parameters may be calculated based on the calculated cardiac parameters and other available measured parameters. The cardiac function parameters provide the clinician with additional information about cardiac function and the performance of the blood pump related to cardiac function. In some embodiments, the cardiac function parameters are also recorded in a memory to provide historical data and trends of the cardiac function parameters over time. In some embodiments, more than one cardiac function parameter is determined.

[0076] For example, cardiac output can be calculated based on the motor current and motor speed of the blood pump and the measured aortic pressure. The pulse pressure of the aortic waveform can be derived from the aortic pressure. Figure 1 In embodiments where the pressure sensor 112 in the pump is located at the outflow of the pump, aortic pressure and pulse pressure of the aortic waveform are measured at the aortic root where they are less affected by aortic and systemic resistance and systemic vascular compliance than by peripheral methods used to calculate pulse pressure (e.g., PiCCO, Edwards FloTract). In some embodiments, pulse pressure, and therefore the algorithm calculation, is affected by aortic compliance at the measurement point (which varies from patient to patient). However, inter-patient variability can be accounted for by calibrating the cardiac output algorithm, and aortic compliance should vary only minimally within a patient during the duration of support because aortic root wall properties are not typically affected by vasoactive and inotropic drugs. Other cardiac output algorithms that rely on pulse pressure and pulse pressure wave derivatives (e.g., PiCCO, FloTract, or PulseCo) cannot distinguish pulsatility due to the natural heart from pulsatility due to the support device. In contrast, the algorithm is able to discern between native pulsatility and pump-driven pulsatility, and decouple changes in pulsatility due to changes in flow from the pump or heart.

[0077] In step 416, cardiac function parameters and / or calculated cardiac parameters are generated for display and displayed to the user on a display interface. The calculated cardiac parameters may be accessed in a memory of the controller and processed to prepare the cardiac parameters for display as numbers, waveforms over time, or as maximum or minimum values. The cardiac parameters and cardiac function parameters may be displayed on a display such as a Figure 3 The calculated cardiac parameters, cardiac function parameters, and optionally, a historical view of the cardiac parameters and / or cardiac function parameters over time are displayed to a clinician (e.g., a laboratory technician or nurse in an intensive care setting or a catheterization laboratory) on a display 300 in FIG. The calculated cardiac parameters, cardiac function parameters, and optionally, a historical view of the cardiac parameters and / or cardiac function parameters over time allow the clinician to review and make decisions based on trends in the cardiac parameters and cardiac function parameters. An example of a user interface is shown in FIG. 5 to illustrate the use of the algorithm derived from the algorithm in determining the correct position of the blood pump.

[0078] When the heart pump is implanted in the heart, the display and / or determination of cardiac parameters and cardiac function parameters may be continuous or nearly continuous. This may be advantageous over conventional catheter-based approaches, which only allow sampling of cardiac function at specific times during the cardiac cycle or at discrete points in time. For example, continuous monitoring of cardiac parameters may allow for faster detection of cardiac deterioration. Continuous monitoring of cardiac parameters and cardiac function parameters may illustrate changes in cardiac condition over time. Additionally, if a cardiac assist device is already in place in the patient, cardiac function may be measured without having to introduce an additional catheter into the patient. The cardiac parameters and / or cardiac function parameters may be displayed as described in the accompanying drawings. Figure 3 The user interface may be displayed as shown in FIG. 1 or using any other suitable user interface or report.

[0079] In step 418, optimization of blood pump performance is determined based on the cardiac function parameter and the calculated cardiac parameter. The controller may access the calculated cardiac parameter in memory and compare the cardiac function parameter or the calculated cardiac parameter with stored thresholds to determine whether blood pump performance can be optimized with respect to the patient's cardiac function. For example, the controller may determine that the patient's cardiac function is improving and that the patient can be weaned from blood pump support. Alternatively, the controller may determine that the patient's cardiac function is declining and that blood pump support provided to the patient should be increased. Additionally or alternatively, the controller may determine the presence of an aspiration risk or an aspiration event based on the current placement of the blood pump and determine whether the blood pump position can be optimized. The threshold to which the cardiac function parameter or the calculated cardiac parameter is compared may be pre-set at the time of manufacture, set by a physician via a user interface, or based on previous readings of the patient's cardiac function parameter and the calculated cardiac parameter. For example, the controller may compare the calculated LVP with a threshold to determine whether aspiration risk exists due to the current positioning of the blood pump. In some embodiments, the controller compares the LVP waveform with one or more stored waveforms. In some embodiments, the controller compares minimum and / or maximum points from the LVP waveform to stored threshold values.

[0080] In step 420, a notification regarding the determined optimization of the blood pump performance is generated and displayed. The notification may be accessed from a memory in the controller and based on the determined optimization, and the notification may be generated for display. The notification regarding the optimization of the blood pump performance may be accessed from a memory in the controller and based on the determined optimization, and the notification may be generated for display. Figure 3 . In some embodiments, a notification regarding optimization of blood pump performance is displayed on the home screen. In some embodiments, a notification regarding optimization of blood pump performance is displayed as a pop-up window or an alert. The notification may suggest increasing or decreasing the blood pump motor speed, or may indicate the risk of a positioning problem or aspiration event. In some embodiments, the notification may further indicate a recommendation for resolving the positioning problem or aspiration event, such as by recommending increasing or decreasing the blood pump motor speed or recommending moving the blood pump a certain distance in a particular direction. In some embodiments, the recommended change in motor speed may exceed the speed of the currently used blood pump, and the notification may recommend changing the blood pump type.

[0081] In some embodiments, the displayed notification is interactive, and the controller can take action regarding the recommended change in motor speed based on input from the clinician. In other embodiments, the notification can indicate that the recommended change in motor speed has been made automatically by the controller.

[0082] Figure 5AA user interface 500 for a cardiac pump controller illustrating intermittent or diastolic pumping events at a blood pump is shown. The user interface 500 includes similar components to the user interface 300, and for simplicity, not all components are labeled or shown here. The user interface 500 includes a first graph 505 showing an aortic pressure waveform 504 and an LVP waveform 506, and a second graph 507 showing a motor current waveform. The user interface also includes an indication of aortic pressure 508, including minimum and maximum values, on the aortic pressure waveform 504, and an indication of LVP 512, including minimum and maximum values, on the LVP waveform 506. Also included in the user interface 500 are an indication of the current motor speed 510, a warning pop-up window 514, and instructions or recommendations 516 for resolving the warning pop-up window.

[0083] The aortic pressure waveform 504 and LVP waveform 506 measured by the controller based on the blood pump's pressure readings and motor current help detect diastolic and intermittent suction events at the blood pump caused by insufficient blood volume in the heart. During such suction events, the LVP waveform 506 drops below zero in the first graph 505 in early diastole but recovers before the end-diastolic pressure point. The systolic phase of the LVP waveform 506 is normal. These events can also be detected by the indication of LVP 512 and the indication of aortic pressure 508 because the maximum indication of LVP 512 is typically normal and greater than the maximum indication of aortic pressure 508, while the minimum indication of LVP 512 is abnormal and very low or less than zero during intermittent and diastolic suction events. Therefore, the minimum value of the indication of LVP 512 provides an early indicator of diastolic suction. The controller may issue a warning 514 based on a comparison of the indicated minimum value of LVP 512 to a threshold value (e.g., 0 mmHg, -10 mmHg, -20 mmHg, -30 mmHg, -40 mmHg, or any other suitable threshold value). In some embodiments, the comparison of the indicated minimum value of LVP 512 can be used to determine the risk level or severity of the aspiration event, for example, where 0 mmHg indicates borderline or low risk, -10 mmHg indicates mild aspiration risk, -20 mmHg indicates moderate aspiration risk, etc. The controller may further provide a recommendation 516 to the physician, nurse, or technician regarding how to respond to warning 514 to address and correct the aspiration event. For example, the controller may provide a recommendation to check additional cardiac indicators to determine the cause of the aspiration event or to conduct a review of the patient's health before adjusting the positioning of the blood pump or the level of cardiac support. The controller may also provide instructions or recommendations to check the positioning of the blood pump based on the detection of the aspiration event, and may further recommend changing the level of support provided by the blood pump by changing the motor current 510.

[0084] Figure 5BA user interface 501 for a heart pump controller is shown illustrating successive pumping events at a blood pump. Figure 5A , user interface 501 includes similar components to user interface 300, and for simplicity, not all components are labeled or displayed here. User interface 501 includes a first graph 525 showing an aortic pressure waveform 524 and an LVP waveform 526, and a second graph 527 showing a motor current waveform. The user interface also includes an indication of aortic pressure 528, including minimum and maximum values, on the aortic pressure waveform 524, and an indication of LVP 532, including minimum and maximum values, on the LVP waveform 526. Also included in user interface 501 are an indication of current motor speed 530, a warning pop-up window 534, and instructions or recommendations 536 for resolving the warning pop-up window.

[0085] With through Figure 5A Similar to the process used to determine and illustrate intermittent (diastolic) suction events based on the displayed LVP and aortic pressure in the user interface 501, the determination of continuous or systolic suction events is indicated by LVP waveform 526 and aortic pressure waveform 524, indications of LVP 528, and indications of aortic pressure 532. By displaying these and other cardiac indicators to the user via user interface 501, a user (such as a clinician or physician) can be aware of continuous suction events and can respond appropriately to address them. Continuous suction events are typically caused by poor positioning of the blood pump or cardiac structures obstructing the blood pump inflow (e.g., pump inlet 114). During a continuous suction event, LVP waveform 526 drops below zero during diastole and never rises above aortic pressure waveform 524 during systole. Additionally, during a continuous suction event, the indicated maximum value of LVP 532 is abnormal and typically well below the indicated maximum value of aortic pressure 528, while the indicated minimum value of LVP 532 is abnormal and less than zero. The LVEDP calculated from the LVP waveform 526 (if displayed) is equal to zero.

[0086] As in Figure 5A As in the case of an intermittent (diastolic) puff event, when a continuous puff event is detected, a warning 534 and a recommendation 536 may be displayed. The recommendation 536 displayed when a continuous puff event is detected may be the same as or different from the recommendation 516 displayed during an intermittent puff event.

[0087] Figure 5CA user interface 502 for a cardiac pump controller is shown illustrating a metric trend screen. The trend screen includes a first graph 540 displaying a cardiac output trend waveform 542, a blood pump flow trend waveform 544, and a native cardiac output trend waveform 546, along with associated values ​​for cardiac output, blood pump flow, and native cardiac output, for quick assessment by a physician. The user interface 502 metric trend screen also includes a second graph 548 displaying a mean aortic pressure trend waveform 550 and a LVEDP trend waveform 552, along with associated values ​​for mean aortic pressure 554 and LVEDP 556. The user interface 502 also includes indications of the blood pump's motor speed 560, blood pump flow 562, cardiac output 564, and cardiac power output 558.

[0088] The indicator trend screen of the user interface 502 is accessible to the physician to further illustrate historical data associated with various cardiac parameters over time. Such historical data can help the physician understand the progression of the patient's cardiac health and identify ongoing events. For example, Figure 5C The indicator trend screen of user interface 502 shown in FIG. 5 displays a cardiac output trend waveform 542, a blood pump flow trend waveform 544, a native cardiac output trend waveform 546, an aortic pressure trend waveform 550, and an LVEDP trend waveform 552, all of which are relatively stable over time. However, changes or trends in these waveforms over time may indicate an aspiration event or risk of aspiration. The LVEDP trend waveform 552 should be stable during the course of providing cardiac support to the patient. A low and / or declining LVEDP trend waveform 552 indicates an increased risk of diastolic aspiration. Making this waveform readily available to the physician enables the physician to monitor the risk of aspiration events. To determine the cause of aspiration, the physician can consult the indicator trend screen of user interface 502, where a high LVEDP trend waveform 552 that suddenly drops to zero indicates a continuous or systolic aspiration event, while a low LVEDP trend waveform 552 that hovers around zero indicates an intermittent or diastolic aspiration event. Displaying these trends and values ​​is made possible by utilizing a controller algorithm to calculate indices from blood pump motor current and aortic pressure, and the physician is able to make informed decisions regarding patient care based on the values ​​and trends.

[0089] In addition to simply providing an indication of a pumping event, the display of multiple waveforms and average cardiac index values ​​can provide the physician with information that enables the physician to determine positioning errors of the blood pump. For example, by observing the LVP waveform (e.g., Figure 5A 506 or Figure 5B 526) relative to the aortic pressure waveform (e.g., Figure 5A 504 or Figure 5BBy observing changes in the LVP waveform (524 in FIG), a physician or technician can determine that the blood pump has migrated into the left ventricle and, as a result, is no longer providing adequate support. When the blood pump migrates into the left ventricle, the change in the shape of the LVP waveform provides immediate feedback that a positioning error has occurred. Comparison of the LVP maximum and minimum values ​​with the aortic pressure maximum and minimum values ​​can indicate to the physician that the aortic pressure values ​​have begun to reflect the left ventricular signal rather than the aortic pressure. At the same time, the LVEDP remains stable, confirming that despite the pump migration, no ventricular structures have been compromised in the flow area.

[0090] The waveform display can also be useful during repositioning of a pump that has been relocated to the left ventricle. Separate LVP and aortic pressure waveforms can be viewed to confirm the distinct aortic pressure signals, and the LVP and aortic pressure waveforms can provide immediate feedback to the physician or technician during repositioning. A comparison of the LVP indication with the aortic pressure indication can also be viewed, and because the aortic pressure values ​​are separate from the LVP values, this comparison can confirm the repositioning of the blood pump.

[0091] If a blood pump positioning problem is detected, the user interface may provide warnings and / or recommendations in addition to displaying waveforms and cardiac index values. Recommendations may include suggestions to reduce the pump flow rate or motor speed and access repositioning instructions.

[0092] In addition to displaying cardiac waveforms and values ​​that can indicate to the physician regarding suction events and positioning issues, the calculated cardiac parameters and indices can also inform weaning decisions. Figure 5D A user interface 504 for a heart pump controller is shown that illustrates changes in heart function during weaning, as captured by displayed indicators. The user interface includes a first graph 575 showing an aortic pressure waveform 574 and an LVP waveform 576, and a second graph 577 showing a motor current waveform. The user interface also includes an indication of aortic pressure 578, including minimum, maximum, and average values, on the aortic pressure waveform 574, and an indication of LVP 582, including minimum, maximum, and end-diastolic (LVEDP) values, on the LVP waveform 576. An indication of current motor speed 580, an indication of blood pump flow rate 588, an indication of cardiac output 586, and an indication of cardiac power output 584 are also included in the user interface 504.

[0093] exist Figure 5DThe LVP waveform 576 and aortic pressure waveform 575 shown in the figure illustrate a hemodynamically stable recovering patient. LVEDP should be stable during the weaning process as the native heart takes over the function and clears the excess left ventricular volume. Cardiac output should similarly be stable during weaning as the native heart takes over the pump output, and cardiac power output should be stable and preferably within the range required by the specific institution's decision-making protocol. The recovering patient's progress during weaning can also be visualized on the indicator trend screen, where the blood pump flow (e.g., blood pressure) decreases as support from the blood pump decreases over time. Figure 5C 544), natural cardiac output occurs (e.g., Figure 5C The natural heart takes over the function of the blood pump during the separation process, and cardiac output (e.g., Figure 5C 542) remain stable. When the native heart takes over, LVEDP (e.g. Figure 5C Finally, cardiac power output (e.g., Figure 5C 558) is stable.

[0094] In the case of a patient whose condition is deteriorating, the LVEDP is likely to rise during the weaning attempt because the heart is unable to pump the excess blood volume and the left ventricle volume increases. During this time, the LVP waveform 576 and the aortic pressure waveform 574 may decrease. During weaning in an ailing patient, cardiac output 586 and cardiac power output 584 also decrease because the native heart is unable to compensate for the reduced support from the blood pump. The reduced function of an ailing patient during weaning can also be visualized on the indicator trend screen, where the native heart output (e.g., Figure 5C 546 in ) may decrease over time as the patient becomes more dependent on blood pump support. When the heart is unable to pump blood and LVP increases, the LVEDP waveform (e.g., Figure 5C Since the total power output is lower, the cardiac power output (e.g. Figure 5C 558) in the reduction.

[0095] Figure 6 A process 600 is shown for determining cardiac power output and displaying recommendations for adjustments to pump support to a user. Figure 1The process 600 is performed using an intravascular heart pump system 100 or any other suitable heart pump. The cardiac power output and historical trends of cardiac power output over time can be interpreted and evaluated by a physician in a critical care setting or catheterization laboratory to monitor trends in indicators during the weaning process and assess the patient's readiness for weaning the heart from blood pump support. In addition, cardiac output, native cardiac output, and LVEDP can also be generated and displayed to the physician to inform decisions about weaning the patient.

[0096] To determine the patient's cardiac power output, the algorithm proceeds according to the following process. In step 602, the motor of the heart pump is operated. The motor can be operated at a constant rotational speed. In step 604, the aortic pressure is measured. The aortic pressure can be measured by a pressure sensor connected to the heart pump, by a separate catheter, by a non-invasive pressure sensor, or by any other suitable sensor. The pressure sensor can be a fluid-filled tube, a differential pressure sensor, a hydraulic sensor, a piezoresistive strain gauge, an optical interferometry sensor or other optical sensor, a MEMS piezoelectric sensor, or any other suitable sensor. In some embodiments, in addition to or as an alternative to measuring the aortic pressure, the ventricular pressure is also measured.

[0097] In step 606, the current delivered to the motor is measured, and the motor speed is measured. The current may be measured using a current sensor or by any other suitable means.

[0098] In step 608, a pulse pressure wave is calculated from the aortic pressure waveform by subtracting the minimum aortic pressure from the maximum aortic pressure. The mean aortic pressure can also be extracted from the average of the aortic pressure waveform. In step 610, the native cardiac output is derived from the pulse pressure. To calculate the native cardiac output, the relationship between pulse pressure and native cardiac output must first be determined by a linear scaling factor. The scaling factor is specific to both the patient and the condition and can be derived from internal or external calibration methods. In step 612, the pump flow is derived from the measured motor current and motor speed. In step 614, the total cardiac output is determined by adding the pump flow to the native cardiac output. In step 616, the cardiac power output is calculated from the total cardiac output and the mean aortic pressure.

[0099] In step 618, a recommendation for adjusting the cardiac pump support is determined based on the calculated cardiac power output. For example, if the calculated cardiac power output is compared to a threshold or historical value, or the calculated cardiac power output indicates that the patient has improved cardiac function, a recommendation to reduce pump support to wean the patient off cardiac support may be determined. In another example, if the calculated cardiac power output is compared to a threshold or historical value, or the calculated cardiac power output indicates that cardiac function has worsened, a recommendation to increase pump support for the patient may be determined. Finally, in step 620, a recommendation for adjusting the pump support is generated for display and displayed on a user interface. In some embodiments, cardiac power output and other calculated indicators and parameters are also generated for display and displayed along with the recommendation for adjusting pump support. The calculated cardiac power output, and optionally a historical view of cardiac power output over time, allows a clinician to review and make decisions based on trends in cardiac power output (e.g., decisions regarding weaning a patient off blood pump support). Displaying trends in these indicators may help the clinician evaluate displayed recommendations for adjustments and support disengagement decisions or other decisions to change the level of support provided by the blood pump.

[0100] Cardiac power output is the product of cardiac output and mean aortic pressure and indicates a true measure of the power coming from the heart and the pump just distal to the aortic valve. This can be measured based on the positioning of a pressure sensor at the pump outflow of the blood pump and an understanding of the operation of the blood pump in terms of cardiac parameters. Clinicians can use native cardiac power output as a measure of the overall health of the heart because native cardiac power output represents the power output by the heart itself. Trends in native cardiac power output can be used by clinicians to determine whether native cardiac output is improving or decreasing, and clinical decisions about support and medication provided by the blood pump can be made based on these trends. The determination of cardiac power output by the algorithm described above is more reliable and accurate than such conventional determination methods.

[0101] Figure 7 A process 700 is shown for recommending adjustments to motor speed based on measured and calculated cardiac parameters. Figure 1 The process 700 is performed using the intravascular heart pump system 100 or any other suitable heart pump. The process 700 includes Figure 4 Steps 402-416 in FIG. 7 are substantially similar to steps 702-716. These steps are briefly described here, but a person of ordinary skill in the art will understand that Figure 4 The alternatives and additional details included in the description of the corresponding steps also apply to Figure 7 Steps 702-716.

[0102] like Figure 4 As in process 400 in FIG. 1 , in step 702, the motor of the heart pump is operated. The motor may be operated at a constant rotational speed. In step 704, the aortic pressure is measured. Figure 4 As in process 400 in FIG. 4 , aortic pressure may be measured by a pressure sensor coupled to the heart pump or by a separate catheter. The sensor may be a fluid-filled tube, a differential pressure sensor, a hydraulic pressure sensor, a piezoresistive strain gauge, an optical interferometry sensor or other optical sensor, a MEMS piezoelectric sensor, or any other suitable sensor. In step 706, the current delivered to the motor is measured, and the motor speed is measured. In step 708, the motor current is measured for the known motor speed by using a lookup table or accessing the motor current. Figure 4 The pressure differential across the cannula of the blood pump is determined based on the measured motor current and motor speed as a function of the other parameters discussed in process 400 in FIG.

[0103] In step 710, a cardiac parameter is calculated based on the aortic pressure and the pressure differential across the cannula of the blood pump. The cardiac parameter can be one of LVEDP, LVP, aortic pulse pressure, mean aortic pressure, pump flow, pressure gradient, or heart rate. Each of these cardiac parameters can be used by a clinician as a measure of various aspects of cardiac health and function. Trends in various cardiac parameters over time can be used by the clinician to determine whether native cardiac output is improving or decreasing, and clinical decisions about support provided by the blood pump and drug therapy can be made based on these trends. In some embodiments, more than one cardiac parameter is calculated based on the aortic pressure and the pressure differential across the cannula of the blood pump.

[0104] The calculated cardiac parameters are recorded in memory in step 712. By accessing the recorded cardiac parameters stored in memory, a historical view of the cardiac parameters over time can be accessed by the user or displayed as a trend line on a display console.

[0105] In step 714, cardiac function parameters are determined based on the calculated cardiac parameters. The cardiac function parameters may be any of the following: cardiac output, cardiac power output, native cardiac output, native cardiac power output, cardiac contractility, cardiac diastole, fluid responsiveness, volume status, cardiac unloading index, cardiac recovery index, left ventricular diastolic function, left ventricular diastolic elastance, left ventricular systolic elastance, stroke volume, heart rate variability, stroke volume variability, pulse pressure variability, aortic compliance, vascular compliance, or vascular resistance. These cardiac function parameters may be calculated based on the calculated cardiac parameters and other available measured parameters. The cardiac function parameters provide the clinician with additional information about cardiac function. In some embodiments, the cardiac function parameters are also recorded in a memory to provide historical data and trends in the cardiac function parameters over time. In some embodiments, more than one cardiac function parameter is determined.

[0106] In step 716, cardiac function parameters and / or calculated cardiac parameters are generated for display and displayed to the user. The cardiac function parameters and / or calculated cardiac parameters are accessed from the memory and generated for display as numerical values, maximum and minimum values ​​within a certain time period and / or as historical trends over time. The display (such as, Figure 3 The cardiac parameters and cardiac function parameters are displayed to the clinician on a display 300 in FIG. The calculated cardiac parameters, cardiac function parameters, and optionally a historical view of the cardiac parameters and / or cardiac function parameters over time allow the clinician to review and make decisions based on trends in the cardiac parameters and cardiac function parameters.

[0107] When the heart pump is implanted in the heart, the display and / or determination of cardiac parameters and cardiac function parameters may be continuous or nearly continuous. This may be advantageous over conventional catheter-based approaches, which only allow sampling of cardiac function at specific times during the cardiac cycle or at discrete points in time. For example, continuous monitoring of cardiac parameters may allow for faster detection of cardiac deterioration. Continuous monitoring of cardiac parameters and cardiac function parameters may illustrate changes in cardiac condition over time. Additionally, if a cardiac assist device is already in place in the patient, cardiac function may be measured without having to introduce an additional catheter into the patient. This may be done as in Figure 3 or using any other suitable user interface or report to display cardiac parameters and / or cardiac function parameters.

[0108] In step 718, a recommended change in motor speed is determined based on the cardiac function parameter and the calculated cardiac parameter. The recommended change in motor speed can be determined based on a comparison of the cardiac parameter and / or the cardiac function parameter with a threshold value. Subsequently, the cardiac parameter or the difference between the cardiac function parameter and the threshold value, or the cardiac parameter and / or the cardiac function parameter, can be used to determine a desired increase or decrease in pump flow, and the increase or decrease in pump flow can be used to determine a corresponding motor speed using a lookup table or other function.

[0109] In step 720, a recommended change in motor speed is generated for display and the recommended change in motor speed is displayed. The recommended change in motor speed may be displayed at Figure 3 . In some embodiments, the recommended change to the motor speed is displayed on the home screen. In some embodiments, the recommended change to the motor speed is displayed as a pop-up window or an alert. In step 722, user input is accepted in response to the displayed recommended change to the motor speed. In step 724, the motor speed is adjusted based on the user input. The motor speed is adjusted by changing the power delivered to the motor. The motor speed can be adjusted to be faster or slower than the current motor speed depending on the user input in response to the recommended change in motor speed. The power delivered to the motor can be adjusted automatically by the controller or manually (e.g., by a healthcare professional). When the patient's heart function is deteriorating, the support level can be increased, or when the patient's heart function is recovering, the support level can be reduced, thereby allowing the patient to be gradually weaned from treatment. This can allow the device to dynamically respond to changes in heart function to promote cardiac recovery. This can also be used to intermittently adjust pump support and diagnose how the heart responds (e.g., whether the heart can take over pumping function from the heart pumping device).

[0110] Figure 8 A process 800 is shown for recommending adjustments to motor speed based on cardiac power output and LVEDP. Figure 1 The process 800 is performed using the intravascular heart pump system 100 or any other suitable heart pump. For the specific case of determining a recommendation for adjustment of motor speed based on cardiac power output and LVEDP, the process 800 follows Figure 7. In step 802, the motor of the heart pump is operated. The motor can be operated at a constant rotational speed. In step 804, the aortic pressure is measured. The aortic pressure can be measured by a pressure sensor connected to the heart pump, by a separate catheter, by a non-invasive pressure sensor, or by any other suitable sensor. The pressure sensor can be a fluid-filled tube, a differential pressure sensor, a hydraulic sensor, a piezoresistive strain gauge, an optical interferometry sensor or other optical sensor, a MEMS piezoelectric sensor, or any other suitable sensor. In some embodiments, in addition to or as an alternative to measuring the aortic pressure, the ventricular pressure is also measured. In step 806, the current delivered to the motor is measured, and the motor speed is measured. The current can be measured using a current sensor or by any other suitable means.

[0111] In step 808, the pressure differential across the cannula of the blood pump is determined based on the measured motor current and motor speed. The controller may access a lookup table (such as a Figure 2A The controller may alternatively utilize a function describing the relationship between differential pressure and motor current to determine the differential pressure across the cannula of the blood pump associated with the measured motor current and the known motor speed. The controller may also consider various other parameters (e.g., characteristics of the blood pump, pump controller, or console, environmental parameters, and motor speed settings) in determining the differential pressure to more accurately determine the pressure gradient across the cannula.

[0112] In step 810, LVEDP and cardiac power output are determined based on the aortic pressure and the pressure gradient across the cannula of the blood pump. LVEDP is calculated by subtracting the pressure gradient across the cannula, determined based on the motor current, from the aortic pressure and selecting the end-diastolic point from the cardiac cycle. Cardiac power output is calculated by first determining the native cardiac output based on the pulse pressure, determining the total cardiac output based on the pump flow, and finally using the cardiac output together with the mean arterial pressure to calculate cardiac power output. In some embodiments, if the blood pump is a right heart blood pump, the right ventricular pressure is determined.

[0113] In step 812, a recommended adjustment to the motor speed of the blood pump is determined. The recommended adjustment to the motor speed can be determined based on a comparison of LVEDP, cardiac power output, cardiac output, and / or mean aortic pressure to a threshold value. Subsequently, the compared cardiac parameter or the difference between the compared cardiac parameter or cardiac function parameter and the threshold value can be used to determine the required increase or decrease in pump flow, and the increase or decrease in pump flow can be used to determine the corresponding motor speed using a lookup table or other function.

[0114] In step 814, a recommended adjustment to the motor speed of the blood pump is generated for display and the recommended adjustment to the motor speed of the blood pump is displayed. The recommended change to the motor speed may be displayed at Figure 3 In some embodiments, the recommended change to motor speed is displayed on the home screen. In some embodiments, the recommended change to motor speed is displayed as a pop-up notification or warning.

[0115] Figure 9 A process 900 for a device for recommending a higher flow rate for treatment based on measured and calculated cardiac parameters is shown. The process 900 includes Figure 7 Steps 702-718 in FIG. 7 are substantially similar to steps 902-918. These steps are briefly described here, but a person of ordinary skill in the art will understand that Figure 7 The alternatives and additional details included in the description of the corresponding steps also apply to Figure 9 Steps 902-918.

[0116] In step 902, the motor of the heart pump is operated. In step 904, the aortic pressure is measured. In step 906, the current delivered to the motor is measured, and the motor speed is measured. In step 908, the pressure difference across the cannula of the blood pump is determined based on the measured motor current and the measured motor speed. In step 910, cardiac parameters are calculated based on the aortic pressure and the pressure difference across the cannula of the blood pump. In step 912, the calculated cardiac parameters are recorded in a memory. The calculated cardiac parameters can be any of LVEDP, LVP, aortic pulse pressure, mean aortic pressure, pump flow, pressure gradient, or heart rate. In step 914, cardiac function parameters are determined based on the calculated cardiac parameters. The cardiac function parameter may be any of the following: cardiac output, cardiac power output, native cardiac output, native cardiac power output, cardiac contractility, cardiac diastolic function, fluid responsiveness, volume status, cardiac unloading index, cardiac recovery index, left ventricular diastolic function, left ventricular diastolic elastance, left ventricular systolic elastance, stroke volume, heart rate variability, stroke volume variability, pulse pressure variability, aortic compliance, vascular compliance, or vascular resistance. In step 916, the cardiac function parameter and / or the calculated cardiac parameter are generated for display and displayed to the user. The recorded cardiac parameters are accessed from a memory and processed for display as instantaneous values, set maximum and minimum values ​​over a time period, and / or as historical trends over time. The recorded cardiac parameters are then displayed to the user. In some embodiments, the calculated cardiac function parameters are also stored and displayed as trends over time. In step 918, a recommended change in motor speed is determined based on the cardiac function parameter and the calculated cardiac parameter.

[0117] In step 920, the recommended change in motor speed is compared to a threshold. The threshold may be a value associated with the blood pump that indicates a maximum or minimum operating motor speed. The recommended change in motor speed is compared to the threshold to determine whether the current blood pump is capable of operating at the desired speed and / or whether the current blood pump is the optimal blood pump for operating at the desired speed.

[0118] In step 922, a blood pump suitable for operation at the recommended motor speed is determined based on a comparison with a threshold value. The appropriate blood pump can be determined by consulting a lookup table including properties and characteristics of a plurality of available blood pumps. The determination of a blood pump suitable for operation at the recommended motor speed can also take into account cardiac function parameters and / or calculated cardiac parameters. Taking into account cardiac function parameters and / or calculated cardiac parameters can enable the controller to make recommendations based not only on the recommended pump speed, but also on overall cardiac function and health. In some cases, it may be unwise to change to a different blood pump because the patient has poor cardiac function. When changing the blood pump to adjust the motor speed would be unwise, taking into account cardiac function and calculated cardiac parameters or alternatively displaying a warning to the clinician along with the recommendation prevents changing the blood pump to adjust the motor speed.

[0119] In step 924, the determined appropriate blood pump is generated for display and the determined appropriate blood pump is displayed. The cardiac parameters and cardiac function parameters may be displayed on a display such as, Figure 3 The recommended motor speed is also displayed to the clinician on a display 300 in FIG. 1 . In some embodiments, the recommended motor speed is also displayed. As noted above, additional information or warnings to the clinician may also be displayed when a different blood pump is recommended, prompting the clinician to follow the protocol or make additional determinations about cardiac function and health before acting on the recommendation.

[0120] Figure 10 A process 1000 for recommending medication therapy based on measured and calculated cardiac parameters is shown. For example, titration of medications (including inotropes and vasopressors) can be monitored and determined based on evaluation of cardiac indices such as cardiac output, mean aortic pressure, and other cardiac indices. Additionally, volume status and fluid responsiveness can be monitored by evaluation of LVEDP over time. The process 1000 for recommending medication therapy includes the following steps: Figure 7 Steps 702-720 in FIG. 1 are substantially similar to steps 1002-1020. These steps are briefly described here, but a person of ordinary skill in the art will understand that Figure 7 The alternatives and additional details included in the description of the corresponding steps also apply to Figure 10 Steps 1002-1020.

[0121] In step 1002, the motor of the heart pump is operated. In step 1004, the aortic pressure is measured. In step 1006, the current supplied to the motor is measured, and the motor speed is measured. In step 1008, the pressure difference across the cannula of the blood pump is determined based on the measured motor current and the measured motor speed. In step 1010, a cardiac parameter is calculated based on the aortic pressure and the pressure difference across the cannula of the blood pump. The calculated cardiac parameter can be any of LVEDP, LVP, aortic pulse pressure, mean aortic pressure, pump flow, pressure gradient, or heart rate. In step 1012, the calculated cardiac parameter is recorded in a memory. In step 1014, a cardiac function parameter is determined based on the calculated cardiac parameter. The cardiac function parameter may be any of the following: cardiac output, cardiac power output, native cardiac output, native cardiac power output, cardiac contractility, cardiac diastolic function, fluid responsiveness, volume status, cardiac unloading index, cardiac recovery index, left ventricular diastolic function, left ventricular diastolic elastance, left ventricular systolic elastance, stroke volume, heart rate variability, stroke volume variability, pulse pressure variability, aortic compliance, vascular compliance, or vascular resistance. In some embodiments, the cardiac function parameter is also stored in the memory. In step 1016, the cardiac function parameter and / or the calculated cardiac parameter is displayed.

[0122] In step 1018, a recommended treatment is determined based on the cardiac function parameter and the calculated cardiac parameter. The recommended treatment is based on the cardiac function parameter and the calculated cardiac parameter. In some embodiments, the recommended treatment is based on a comparison of the cardiac function parameter and / or the calculated cardiac parameter to a threshold value. In some embodiments, the recommended treatment is based on a comparison of changes in the cardiac function parameter and / or the calculated cardiac parameter over a period of time. In some embodiments, the recommended treatment is determined by accessing a lookup table and retrieving a dose corresponding to the current value of the cardiac function parameter and the calculated cardiac parameter.

[0123] For example, a combination of calculated cardiac parameters of native cardiac output, LVEDP, and cardiac power output can be analyzed by an algorithm and compared to thresholds to determine that pharmacological intervention is warranted or would be beneficial. The algorithm can determine that administration of an inotrope is warranted, and further analysis (such as consulting a lookup table of dosages) can allow the algorithm to provide a clinician with a recommendation to administer the inotrope and a recommendation for a specific dose or titration at which the treatment should be administered.

[0124] Monitoring and analyzing additional cardiac parameters allows the algorithm to also provide information and recommendations to the clinician to adjust the patient's fluid intake or administer diuretics to the patient. By measuring and determining cardiac parameters such as native output, LVEDP, and changes in aortic pulse pressure, the algorithm can identify the patient's status and whether the patient is in the optimal fluid window, and can also assess and report on the patient's fluid responsiveness.

[0125] In step 1020, a recommended dose associated with the recommended treatment is determined. The recommended dose is based on the cardiac function parameter and the calculated cardiac parameter. In some embodiments, the recommended dose is based on a comparison of the cardiac function parameter and / or the calculated cardiac parameter to a threshold value. In some embodiments, the recommended dose is based on a comparison of changes in the cardiac function parameter and / or the calculated cardiac parameter over a period of time. In some embodiments, the recommended dose is determined by accessing a lookup table for the recommended treatment and retrieving the dose corresponding to the current value of the cardiac function parameter and the calculated cardiac parameter.

[0126] In step 1022, a recommended treatment and a recommended dosage are generated for display and displayed. The recommended treatment and the recommended dosage may be displayed on Figure 3 In some embodiments, the recommended treatment and recommended dosage are displayed on the home screen. In some embodiments, the recommended treatment and recommended dosage are displayed as pop-up windows or alerts. In a manner similar to that in process 900, the recommended treatment and recommended dosage can be displayed to the clinician using an alert to prompt the clinician to follow a specific protocol or to monitor or check other cardiac function parameters before administering any treatment.

[0127] Figure 11 A process 1100 is shown for alerting a user of a predicted adverse cardiac event based on measured and calculated cardiac parameters. The process 1100 includes Figure 7 Steps 702-720 in FIG. 1 are substantially similar to steps 1102-1120. These steps are briefly described here, but a person of ordinary skill in the art will understand that Figure 7 The alternatives and additional details included in the description of the corresponding steps also apply to Figure 11 Steps 1102-1120.

[0128] In step 1102, the motor of the heart pump is operated. In step 1104, the aortic pressure is measured. In step 1106, the current supplied to the motor is measured, and the motor speed is measured. In step 1108, the pressure difference across the cannula of the blood pump is determined based on the measured motor current and the measured motor speed. In step 1110, a cardiac parameter is calculated based on the aortic pressure and the pressure difference across the cannula of the blood pump. The calculated cardiac parameter can be any of LVEDP, LVP, aortic pulse pressure, mean aortic pressure, pump flow, pressure gradient, or heart rate. In step 1112, the calculated cardiac parameter is recorded in a memory. In step 1114, a cardiac function parameter is determined based on the calculated cardiac parameter. The cardiac function parameter may be any of the following: cardiac output, cardiac power output, native cardiac output, native cardiac power output, cardiac contractility, cardiac diastolicity, fluid responsiveness, volume state, cardiac unloading index, cardiac recovery index, left ventricular diastolic function, left ventricular diastolic elastance, left ventricular systolic elastance, stroke volume, heart rate variability, stroke volume variability, pulse pressure variability, aortic compliance, vascular compliance, or vascular resistance. In some embodiments, the cardiac function parameter is also stored in the memory. In step 1116, the cardiac function parameter and / or the calculated cardiac parameter are generated for display and displayed to the user. The cardiac function parameter and / or the calculated cardiac parameter may be generated for display as an instantaneous value, a maximum and minimum value over a certain time period, and / or as a historical trend over time. The cardiac function parameter and / or the calculated cardiac parameter are then displayed to the user.

[0129] In step 1118, the cardiac function parameter and / or the calculated cardiac parameter is compared to a threshold value. In some embodiments, the set threshold value is a system value set within the controller. In some embodiments, the set threshold value is set by a clinician based on the patient's history and health. In some embodiments, the set threshold value is a previous value of the cardiac index (e.g., a previous value measured or calculated a predetermined amount of time ago). In step 1120, it is determined whether the cardiac function parameter and / or the calculated cardiac parameter meets the threshold value. The set threshold value is set so that the cardiac parameter or cardiac function parameter meeting the threshold value is an indication or possible indication of an early warning sign of an ongoing cardiac or ischemic event.

[0130] Many adverse events can be predicted based on the determination of cardiac parameters and comparison of cardiac parameters or their trends over time with threshold values. In addition, displaying these additional cardiac parameters to health care professionals in real time and including historical data enables doctors to better understand patient health and predict and resolve possible adverse events. For example, additional ischemic events, conduction abnormalities, or bleeding and hemolysis can be detected and resolved based on the cardiac parameters calculated and displayed according to the algorithms described herein. Doctors can make clinical decisions based on the prediction of such adverse events (such as optimizing support to maximize natural recovery and balancing left support with right support).

[0131] In step 1122, an alarm is triggered regarding the cardiac parameter and / or cardiac function parameter. The alarm may be an audible alarm or may be triggered at a Figure 3 In some embodiments, the alert can be displayed in the user interface of the device. In some embodiments, the alert can be sent to the clinician via a web page, text, or email via a Wi-Fi network, Bluetooth signal, or cellular signal. In some embodiments, the warning is displayed on the home screen. In some embodiments, the warning is displayed as a pop-up message. In some embodiments, the warning can be turned off or muted by the clinician.

[0132] Figure 12 A process 1200 is shown for balancing a right-sided blood pump device with a left-sided blood pump device during biventricular support based on measured and calculated cardiac parameters. When both left and right-sided devices provide simultaneous cardiac support, balancing right-sided output with left-sided output to maintain appropriate pressure in the lungs and limit the risk of pulmonary edema can be challenging. Measuring native cardiac output and total output along with pulmonary artery pressure and left ventricular diastolic pressure enables clinicians to better balance right-sided support with left-sided support.

[0133] In step 1202, the first motor of a first blood pump is operated. The first motor of the first blood pump may be, for example, a right-sided device placed in the right ventricle and pulmonary artery of the heart. In step 1204, the second motor of a second blood pump is operated. The second motor of the second blood pump may be, for example, a left-sided device placed in the left ventricle and aorta of the heart. The first and second motors are operated simultaneously to provide support to both sides of the heart. In step 1206, the pressure at the pump outlet is measured. For the second pump (left-sided device), this pressure is the aortic pressure. For the first pump (right-sided device), this pressure is the pulmonary artery pressure. The aortic pressure can be measured by a pressure sensor connected to the heart pump, by a separate catheter, by a non-invasive pressure sensor, or by any other suitable sensor. The pressure sensor may be a fluid-filled tube, a differential pressure sensor, a hydraulic pressure sensor, a piezoresistive strain gauge, an optical interferometry sensor or other optical sensor, a MEMS piezoelectric sensor, or any other suitable sensor. In some embodiments, in addition to or as an alternative to measuring aortic pressure, ventricular pressure is also measured.

[0134] At step 1208, a first motor current and a first motor speed of the first blood pump are measured, and a second motor current and a second motor speed of the second blood pump are measured. At step 1210, a first pressure differential across the first cannula of the first blood pump is determined based on the measured first motor current and the measured first motor speed, and a second pressure differential across the second cannula of the second blood pump is determined based on the measured second motor current and the measured second motor speed. The first and second pressure differentials can be determined using a lookup table or by accessing a function that takes into account the measured motor current, the measured motor speed, and optionally other parameters.

[0135] In step 1212, a first cardiac parameter is calculated based on a first pump outlet pressure and a first pressure differential across a first cannula of the first blood pump, and a second cardiac parameter is calculated based on a second pump outlet pressure and a second pressure differential across a second cannula of the second blood pump. The first cardiac parameter from the right-side device may be any of right ventricular pressure, right ventricular end-diastolic pressure, pulmonary artery pressure, right arterial pressure, central venous pressure, or blood pump flow rate. The second cardiac parameter from the left-side device may be any of LVEDP, LVP, aortic pulse pressure, mean aortic pressure, pump flow, pressure gradient, heart rate, or right arterial pressure. Each of these cardiac parameters can be used by the clinician as a measure of various aspects of cardiac health and function and to better balance the right-side device with the left-side device to provide balanced cardiac support.

[0136] Furthermore, trends in various cardiac parameters over time can be used by clinicians to determine whether native cardiac output is improving or decreasing, and clinical decisions regarding support provided by the blood pump and medication therapy can be made based on these trends. In some embodiments, more than one cardiac parameter is calculated based on aortic pressure and the pressure differential across the cannula of the blood pump.

[0137] In step 1214, a cardiac function parameter is determined based on the calculated first cardiac parameter and / or the calculated second cardiac parameter. The cardiac function parameter may be any of cardiac output, cardiac power output, native cardiac output, native cardiac power output, cardiac contractility, cardiac diastolicity, fluid responsiveness, volume status, cardiac unloading index, cardiac recovery index, left ventricular diastolic function, left ventricular diastolic elastance, left ventricular systolic elastance, stroke volume, heart rate variability, stroke volume variability, pulse pressure variability, aortic compliance, vascular compliance, or vascular resistance, or similar parameters associated with right-sided support. These cardiac function parameters may be calculated based on the calculated cardiac parameter and other available measured parameters. The cardiac function parameters provide the clinician with additional information regarding cardiac function and the balance of support provided by the first and second blood pumps. In some embodiments, the cardiac function parameters are also recorded in a memory to provide historical data and trends in the cardiac function parameters over time. In some embodiments, more than one cardiac function parameter is determined.

[0138] In step 1216, a recommended change to the level of support provided by the first blood pump and / or the second blood pump is determined. The recommended change to the level of support may be accessed from a lookup table stored in memory or may be calculated based on current or historical values ​​of cardiac parameters and cardiac function parameters. The recommended change to the level of support may include a prompt to increase or decrease pump support and / or may include a recommendation for the amount of change to be made to pump support.

[0139] In step 1218, a recommended change in the level of support provided by the first blood pump and / or the second blood pump is generated for display and displayed. The recommended change in the level of support provided by the first blood pump and / or the second blood pump may be displayed on Figure 3In some embodiments, a recommended change to the level of support provided by the first blood pump and / or the second blood pump is displayed on the home screen. In some embodiments, the recommended change to the level of support provided by the first blood pump and / or the second blood pump is displayed as a pop-up window or alert. The recommended change to the level of support provided by the first blood pump and / or the second blood pump can be displayed to the clinician along with additional information about the first blood pump and the second blood pump, and a prompt to follow the protocol and perform further checks before changing the level of support provided by adjusting the motor speed of the first blood pump or the second blood pump. In some embodiments, the controller can determine a change in the motor speed that is appropriate for one or both of the first blood pump and the second blood pump, and can also determine whether the first blood pump and the second blood pump currently providing support are the optimal blood pumps to operate at the recommended motor speed to provide the recommended level of support.

[0140] Using data collected by one or more blood pumps and blood pump systems to calculate clinically relevant cardiac parameters and cardiac function parameters and displaying the parameters to the clinician in real time provides the clinician with important information about cardiac health and function that can be used to support clinical decision making. Additionally, algorithms within the blood pump controller or console that help the clinician identify potential problems and provide recommendations to improve cardiac function give the clinician the ability to detect problems earlier and respond to them more quickly than they would without this important information.

[0141] Figure 13 A block diagram 1300 of a process for automatically modifying the level of support provided by a blood pump is shown. In step 1302, a blood pump positioned in the heart is operated to provide a certain level of cardiac support to the heart. The blood pump has a cannula and a motor that operates at a motor speed and draws a variable current to provide support to the heart. At step 1304, a controller coupled to the blood pump measures aortic pressure in the heart. At step 1306, the controller measures the motor current and the motor speed. At step 1308, the controller determines a pressure gradient across the cannula that is associated with the motor current and the motor speed.

[0142] At step 1310, the processor calculates a calculated cardiac parameter based on the aortic pressure and the pressure gradient across the cannula associated with the motor current and the motor speed. At step 1312, the calculated cardiac parameter is recorded in a memory. At step 1314, a cardiac function parameter is determined based on the calculated cardiac parameter. In some embodiments, the cardiac function parameter is also stored in the memory. At step 1316, a recommended change in the level of cardiac support provided by the blood pump is determined based on at least one of the cardiac function parameter and the calculated cardiac parameter. At step 1318, the recommended change in the level of cardiac support is generated for display.

[0143] In some embodiments, more than one cardiac parameter is calculated based on the aortic pressure and the pressure gradient across the cannula. For example, any number of cardiac parameters can be calculated, including LVEDP, LVP, aortic pulse pressure, mean aortic pressure, pump flow, pressure gradient, or heart rate. In some embodiments, these cardiac parameters are also generated for display as maximum or minimum values, average values, instantaneous values, historical trends, or waveforms. In some embodiments, more than one cardiac function parameter is determined based on the cardiac parameters. For example, the cardiac function parameter can be cardiac output, cardiac power output, native cardiac output, native cardiac power output, cardiac contractility, cardiac diastolicity, fluid responsiveness, volume status, cardiac unloading index, cardiac recovery index, left ventricular diastolic function, left ventricular diastolic elastance, left ventricular systolic elastance, stroke volume, heart rate variability, stroke volume variability, pulse pressure variability, aortic compliance, vascular compliance, or vascular resistance.

[0144] In some embodiments, the calculated cardiac parameter is LVEDP, and the cardiac function parameter is cardiac power output. By calculating LVEDP and cardiac power output, a recommendation for adjustment of cardiac support can be determined based on historical data. Based on the patient's cardiac health as described by LCEDP and cardiac power output, a recommendation to increase motor speed (to provide increased cardiac support from the blood pump to a patient whose health is deteriorating) or to decrease motor speed (to wean a patient whose health is improving off the blood pump) can be determined, generated for display, and displayed to a healthcare professional.

[0145] Such a recommendation can be determined by comparing the current value of LVEDP and / or cardiac power output with a previous value or a set threshold. A lookup table stored in memory can provide a recommendation based on the comparison, which can include an indication of a recommended change in the determined level of support and a list of steps to implement the recommended change. Alternatively, in some embodiments, the recommended change in the level of cardiac support can be automated by the controller.

[0146] Various combinations of cardiac indicators and parameters can be useful in determining aspects of a patient's cardiac health and the functioning of both the heart and the blood pump. The values ​​of these parameters, along with recommendations and warnings generated by algorithms based on historical information or based on current thresholds of a patient's health, enable healthcare professionals to make informed decisions about supportive adjustments, as well as, as previously described, Figure 4-12 and many other health care decisions described.

[0147] Figure 14 Shown is a method for implementing the above Figure 4-13 14. A block diagram of an exemplary blood pump system 1400 for use with any of the methods described herein is provided. The heart pump system 1400 can be operated intracardially, partially intracardially, externally, partially externally, partially externally, or at any other suitable location in a patient's vascular system. The blood pump system 1400 includes a console 1401 and a blood pump 1402. The console 1401 includes a drive unit 1404, a memory 1406, a processor 1408, a circuit system 1403, and a display 1410.

[0148] The blood pump system 1400 can be used with any suitable blood pump device. For example, the blood pump 1402 can be Figure 1 The blood pump 100 shown in FIG. 1 is used to provide cardiac support to the right or left side of the heart. The blood pump 1402 includes a motor 1405 and a sensor 1407 as well as an unshown Figure 1 In some embodiments, the blood pump system 1400 can be used with two blood pumps to provide cardiac support to the left and right sides of the heart simultaneously.

[0149] Blood pump 1402 is coupled to drive unit 1404 via circuitry 1403. All or part of circuitry 1403 may be separate / remote from blood pump 1402 within console 1401. In some embodiments, circuitry 1403 is located internal to blood pump 1402. Circuitry 1403 and blood pump 1402 are not shown to scale. Drive unit 1404 supplies current to motor 1405 of heart pump 1402 via circuitry 1403. The current supplied by drive unit 1404 to motor 1405 of heart pump 1402 via line 1426 is measured by current sensor 1409 located in or coupled to drive unit 1404.

[0150] The placement signal, or aortic pressure, is measured at a pressure sensor 1407 located on the blood pump 1402. The pressure detected at the pressure sensor 1407 is received by the circuitry 1403 at the drive unit 1404 and may be transmitted to the processor 1408 along with the current supplied to the motor 1405. In some embodiments, the aortic pressure may be measured by the pressure sensor 1407 coupled to the blood pump 1402, by a separate catheter, by a non-invasive pressure sensor, or by any other suitable sensor. The pressure sensor 1407 may be a fluid-filled tube, a differential pressure sensor, a hydraulic pressure sensor, a piezoresistive strain gauge, an optical interferometry sensor or other optical sensor, a MEMS piezoelectric sensor, or any other suitable sensor.

[0151] The processor 1408 includes software and / or hardware that allows the processor 1408 to receive motor current and pressure measurements from the drive unit 1404 and use these values ​​to determine a plurality of additional cardiac parameters and cardiac function parameters. For example, the processor includes software and / or hardware that allows the processor 1408 to receive motor current and pressure measurements from the drive unit 1404 and use these values ​​to determine a plurality of additional cardiac parameters and cardiac function parameters. Figures 2A-2E The method described herein is software for calculating LVP and LVEDP based on the motor current of the blood pump 1402 and the aortic pressure information received from the pressure sensor 1407. In addition, the processor 1408 can store the received measurements, parameters, and values ​​in the memory 1406 and can access the values ​​and parameters stored in the memory to generate for display on the display 1410.

[0152] Processor 1408 further includes executing Figure 4-13 The steps described herein are based on an algorithm that receives or requests values ​​for current and aortic pressure from the drive unit 1404 and determines cardiac parameters and cardiac function parameters indicative of the health or function of the heart based on these values. These values ​​may also be generated for display to the user and displayed on the display 1410.

[0153] The processor 1408 can access functions and lookup tables stored in the memory 1406 to make determinations about cardiac function parameters and calculated cardiac parameters and use these determinations to make recommendations about treatment and support to provide to the patient's heart. The processor 1408 can generate recommendations and display these recommendations on the display 1410.

[0154] Display 1410 can be used with Figure 3The user interface 300 in the console 1401 is substantially similar. The display provides the clinician with clinically relevant cardiac function parameters and calculated cardiac parameters, enabling the clinician to make treatment decisions using real-time data. In addition, the display 1410 allows the processor 1408 to display recommendations to the clinician to allow the clinician to more quickly detect and respond to life-threatening cardiac problems. The processor 1408 on the console 1401 uses the blood pump 1402 and the accessible measurements to provide additional information to the clinician to help the clinician provide more efficient and effective cardiac treatment to the patient.

[0155] The foregoing merely illustrates the principles of the present disclosure, and the device may be practiced by embodiments other than the described embodiments which are presented for purposes of illustration and not limitation. It will be understood that the device disclosed herein, while shown for use in percutaneous insertion of a heart pump, may be adapted for use in devices in other applications.

[0156] Variations and modifications will occur to those skilled in the art after reviewing this disclosure. The disclosed features may be implemented in any combination and subcombination (including multiple dependent combinations and subcombinations) with one or more other features described herein. The various features described or illustrated above (including any components thereof) may be combined or integrated into other systems. In addition, certain features may be omitted or not implemented.

[0157] In general, embodiments of the subject matter and functional operations described in this specification may be implemented in digital electronic circuit systems or in computer software, firmware, or hardware (including the structures disclosed in this specification and their structural equivalents) or in a combination of one or more of the above. The embodiments of the subject matter described in this specification may be implemented as one or more computer program products (i.e., one or more modules of computer program instructions encoded on a computer-readable medium) for execution by a data processing device or for controlling the operation of a data processing device. The computer-readable medium may be a machine-readable storage device, a machine-readable storage substrate, a memory device, a material composition that affects a machine-readable propagation signal, or a combination of one or more of the above. The term "data processing device" includes all devices, devices, and machines for processing data (including, by way of example, a programmable processor, a computer, or multiple processors or computers). In addition to hardware, the device may also include code that creates an execution environment for the computer program in question (e.g., code constituting a processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of the above). A propagation signal is an artificially generated signal (e.g., a machine-generated electrical, optical, or electromagnetic signal) that is generated to encode information for transmission to a suitable receiver device.

[0158] A computer program (also referred to as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program may be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files storing one or more modules, subroutines, or portions of code). A computer program may be deployed to execute on one computer or on multiple computers located at one site or distributed across multiple sites and interconnected by a communications network.

[0159] The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and the apparatus can be implemented as, special purpose logic circuitry, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).

[0160] Processors suitable for executing computer programs include, by way of example, both general-purpose and special-purpose microprocessors and any one or more processors of any type of digital computer. Generally, the processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include one or more mass storage devices (e.g., magnetic disks, magneto-optical disks, or optical disks) for storing data, or be operatively connected to receive data from a mass storage device or transfer data to a mass storage device or both. However, a computer need not have such a device.

[0161] Examples of changes, substitutions, and variations are ascertainable by those skilled in the art and may be made without departing from the scope of the information disclosed herein.All references cited herein are incorporated by reference in their entirety and constitute part of this application.

Claims

1. A system for providing cardiac support to a heart, the system comprising: a blood pump configured to be positioned in the heart, the blood pump comprising: intubation; and a motor operable at a motor speed and configured to draw a variable motor current to provide a level of cardiac support to the heart; and A controller configured to: Measure aortic pressure; measuring the motor current; determining a pressure gradient across the cannula associated with the motor current; calculating a cardiac parameter based on the aortic pressure and the pressure gradient across the cannula associated with the motor current; recording the calculated cardiac parameters in a memory; determining a cardiac function parameter based on the calculated cardiac parameter; determining a question regarding the positioning of the blood pump based on the calculated cardiac parameter and the cardiac function parameter; and Displays a warning.

2. The system according to claim 1, wherein: The blood pump is configured to be positioned in an aortic valve of the heart, and wherein the controller is further configured to determine a distance from a distal end of the blood pump to a feature of the heart.

3. The system according to claim 1 or 2, wherein: The controller is further configured to display a recommendation to reposition the blood pump.

4. The system according to claim 3, wherein: The controller is further configured to display a distance from a distal end of the blood pump to a characteristic of the heart.

5. The system according to claim 1, wherein A problem with the positioning of the blood pump is the aspiration event.

6. The system according to claim 1 or 2, wherein: The cardiac parameter calculated is left ventricular pressure.

7. The system according to claim 1 or 2, wherein: Displaying the warning includes displaying the warning on an interface touch screen, and wherein the controller is further configured to receive input from the interface touch screen in response to display of the warning on the interface touch screen.

8. The system according to claim 1 or 2, wherein: The calculated cardiac parameter is left ventricular pressure, and wherein the left ventricular pressure is displayed as a waveform in real time.

9. The system according to claim 1 or 2, wherein: The blood pump is configured to be positioned in the left ventricle.

10. The system according to claim 1 or 2, wherein: Determining the pressure gradient across the cannula associated with the motor current includes accessing a lookup table.

11. The system according to claim 1, wherein: The controller is further configured to calculating left ventricular pressure and cardiac power output based on the aortic pressure and the pressure gradient across the cannula; determining a recommended adjustment to motor speed based on the calculated left ventricular pressure and the calculated cardiac power output; and The recommended adjustment to the motor speed is displayed on a display.

12. The system according to claim 11, wherein The controller is further configured to display a recommendation to increase the motor speed based on the calculated left ventricular pressure and the calculated cardiac power output.

13. The system according to claim 11, wherein: The controller is further configured to display a recommendation to reduce the motor speed based on the calculated left ventricular pressure and the calculated cardiac power output.

14. The system according to any one of claims 11 to 13, wherein: The controller is further configured to: comparing the calculated left ventricular pressure to a previous left ventricular pressure; and The calculated cardiac power output is compared to a previous cardiac power output.

15. The system according to claim 14, wherein: The controller is further configured to display a recommendation to adjust the motor speed if the calculated left ventricular pressure has increased relative to a previous left ventricular pressure and if the calculated cardiac power output has decreased relative to a previous cardiac power output.

16. The system of claim 14, wherein: The controller is further configured to display a recommendation to adjust the motor speed if the calculated left ventricular pressure has decreased relative to a previous left ventricular pressure and if the calculated cardiac power output has increased relative to a previous cardiac power output.

17. The system according to claim 1 or 2, wherein: The calculated cardiac parameters include at least one of left ventricular end-diastolic pressure, a pressure differential across a cannula of the blood pump, a blood pump flow rate, native cardiac output, total cardiac output, native cardiac power output, or total cardiac power output.

18. The system according to claim 1 or 2, wherein: The cardiac function parameter includes one of a systolic value, a diastolic value, a fluid responsiveness value, a measure of cardiac output, a measure of left ventricular diastolic abnormality, or left ventricular systolic and diastolic elastance.

19. The system of claim 1, wherein: The blood pump is a right heart device.

20. A system for providing cardiac support to a heart, the system comprising: A blood pump configured to be positioned in a heart, the blood pump comprising: intubation; and a motor operable at a motor speed and configured to draw a variable motor current to provide a level of cardiac support to the heart; and A controller configured to: Measure aortic pressure; measuring the motor current; determining a pressure gradient across the cannula associated with the motor current; calculating a cardiac parameter based on the aortic pressure and the pressure gradient across the cannula associated with the motor current; recording the calculated cardiac parameters in a memory; determining a cardiac function parameter based on the calculated cardiac parameter; displaying at least one of the calculated cardiac parameter or the calculated cardiac function parameter; determining a recommended change to the motor speed based on the calculated cardiac parameter and the cardiac function parameter; displaying a recommended change to said motor speed; accepting user input in response to the displayed recommended change to the motor speed; and The motor speed is adjusted based on the user input.

21. A system for providing cardiac support to a heart, the system comprising: A blood pump configured to be positioned in a heart, the blood pump comprising: intubation; and a motor operable at a motor speed and configured to draw a variable motor current to provide a level of cardiac support to the heart; and A controller configured to: Measure aortic pressure; measuring the motor current; determining a pressure gradient across the cannula associated with the motor current; calculating a cardiac parameter based on the aortic pressure and the pressure gradient across the cannula associated with the motor current; recording the calculated cardiac parameters in a memory; determining a cardiac function parameter based on the calculated cardiac parameter; displaying at least one of the calculated cardiac parameter or the calculated cardiac function parameter; determining a recommended treatment, including administration of a therapeutic substance or drug, based on the calculated cardiac parameter and the calculated cardiac function parameter; Recommended treatment including administration of a therapeutic substance or medication is displayed.

22. A system for providing cardiac support to a heart, the system comprising: A first blood pump configured to be positioned in a left side of the heart, the first blood pump comprising: First intubation; and a first motor operable at a first motor speed and configured to draw a variable first motor current; a second blood pump configured to be positioned in the right side of the heart, the second blood pump comprising: Second cannula; and a second motor operable at a second motor speed and configured to draw a variable second motor current; and A controller configured to: Measure aortic pressure; measuring the first motor current and the second motor current; determining a first pressure across the cannula associated with the first motor current and a second pressure across the cannula associated with the second motor current; calculating a first cardiac parameter based on the aortic pressure and a first pressure gradient across the first cannula, and calculating a second cardiac parameter based on the aortic pressure and a second pressure gradient across the second cannula; determining at least one cardiac function parameter based on the calculated first cardiac parameter and the calculated second cardiac parameter; determining a recommended change to a level of support provided by one of the first blood pump and the second blood pump based on the calculated first cardiac parameter, the calculated second cardiac parameter, and the at least one cardiac function parameter to maintain a balance in left and right side support; and A recommended change to a level of support provided by one of the first blood pump and the second blood pump is displayed.

23. A system for providing cardiac support to a heart, the system comprising: A blood pump configured to be positioned in a heart, the blood pump comprising: intubation; and a motor operable at a motor speed and configured to draw a variable motor current to provide a level of cardiac support to the heart; and A controller configured to: Measure aortic pressure; measuring the motor current; determining a pressure gradient across the cannula associated with the motor current; calculating a cardiac parameter based on the aortic pressure and the pressure gradient across the cannula associated with the motor current; recording the calculated cardiac parameters in a memory; determining a cardiac function parameter based on the calculated cardiac parameter; displaying at least one of the calculated cardiac parameter or the calculated cardiac function parameter; comparing at least one of the calculated cardiac parameter or the calculated cardiac function parameter with a first threshold; and If at least one of the cardiac parameter or the cardiac function parameter meets the first threshold, an alarm is triggered.

Images