Conductive sensor for pulmonary artery catheter

Abstract

The pulmonary artery catheter system may include a port housing that is coupled to the catheter and supports a right ventricular port, a right atrial port, a distal pulmonary artery space, a balloon port, and a volume sensor support. The pulmonary artery catheter system may also include multiple volume sensors arranged along the length of the catheter and communicating with the volume sensor support.

Description

[Technical Field]

[0001] This disclosure relates to a pulmonary artery catheter. This disclosure also relates to cardiac volume measurement using admittance and conductance. [Overview of the Initiative]

[0002] In some embodiments, the technology described herein relates to a pulmonary artery catheter system comprising a catheter, a port housing coupled to the catheter and supporting a right ventricular port, a right atrial port, a distal pulmonary artery space, a balloon port, and a volume sensor support, and a plurality of volume sensors arranged along the length of the catheter and communicating with the volume sensor support.

[0003] In some embodiments, the technology described herein relates to a pulmonary artery catheter system, wherein the plurality of volume sensors include a first volume sensor configured to be located in the right ventricle, a second volume sensor configured to be located in the right ventricle, and a third volume sensor configured to be located in the right ventricle.

[0004] In some embodiments, the technology described herein relates to a pulmonary artery catheter system that uses a plurality of volume sensors to determine inflow and outflow vectors.

[0005] In some embodiments, the technology described herein relates to a pulmonary artery catheter system, wherein the plurality of volume sensors include a first volume sensor located at a first distance from the distal tip of the catheter, a second volume sensor located at a second distance from the distal tip of the catheter, and a third volume sensor located at a third distance from the distal tip of the catheter, the second distance being greater than the first distance and the third distance being greater than the second distance.

[0006] In some embodiments, the technology described herein relates to a pulmonary artery catheter system in which a first volume sensor is spaced 20 mm to 150 mm apart from a second volume sensor, and the second volume sensor is spaced 20 mm to 150 mm apart from a third volume sensor.

[0007] In some embodiments, the technology described herein relates to a pulmonary artery catheter system in which the distance between a first volume sensor and a second volume sensor is equal to the distance between a second volume sensor and a third volume sensor.

[0008] In some embodiments, the technology described herein relates to a pulmonary artery catheter system in which each of a plurality of volume sensors includes a conductive sensor.

[0009] In some embodiments, the technology described herein relates to a pulmonary artery catheter system in which each conductive sensor includes an electrode pair.

[0010] In some embodiments, the technology described herein relates to a pulmonary artery catheter system in which each conductive sensor is formed from a flexible conductive material.

[0011] In some embodiments, the technology described herein relates to a pulmonary artery catheter system in which each conductive sensor is formed from a rigid conductive material.

[0012] In some embodiments, the technology described herein further includes a pulmonary artery catheter system comprising a pressure sensor positioned along the length of the catheter, configured to be located in the right ventricle and providing a signal indicating pressure to a right ventricular port.

[0013] In some embodiments, the technology described herein relates to a pulmonary artery catheter system that includes a pressure opening through which a pressure sensor utilizes a fluid-filled catheter.

[0014] In some embodiments, the technology described herein relates to a pulmonary artery catheter system in which the pressure sensor includes a micromanometer.

[0015] In some embodiments, the technology described herein relates to a pulmonary artery catheter system configured such that signals received from a right ventricular port and volume sensor support create a pressure-volume loop in the right ventricle.

[0016] In some embodiments, the technology described herein relates to a pulmonary artery catheter system comprising a catheter defining a distal tip and a proximal port housing; a right ventricular port coupled to the proximal port housing; a right atrial port coupled to the proximal port housing; a distal pulmonary artery space coupled to the proximal port housing; a balloon port coupled to the proximal port housing; a volume sensor support coupled to the proximal port housing; a pressure sensor positioned along the length of the catheter and configured to be located in the right ventricle, providing a signal indicating pressure to the right ventricular port; a first admittance sensor positioned along the length of the catheter; a second admittance sensor positioned along the length of the catheter; and a third admittance sensor positioned along the length of the catheter, wherein at least two of the first admittance sensor, the second admittance sensor, or the third admittance sensor are configured to be located in the right ventricle of the heart.

[0017] In some embodiments, the technology described herein relates to a pulmonary artery catheter system in which each of the first admittance sensor, the second admittance sensor, and the third admittance sensor includes a pair of conductive electrodes.

[0018] In some aspects, the techniques described herein relate to a method that includes inserting a pulmonary artery catheter system into the heart, determining a right ventricular volume based on an admittance or conductance signal received from a volume sensor of the pulmonary artery catheter system disposed within the right ventricle of the heart, determining a right ventricular pressure based on a signal received from a pressure sensor of the pulmonary artery catheter system disposed within the right ventricle, and generating a pressure-volume loop of the right ventricle based on the determined volume and pressure.

[0019] In some aspects, the techniques described herein further relate to a method that includes determining an effective arterial elastance (Ea), an end-systolic elastance (Ees), and an Ees / Ea ratio based on an admittance or conductance signal received from a volume sensor and a signal received from a pressure sensor.

[0020] In some aspects, the techniques described herein relate to a method that includes using inferior vena cava occlusion to generate an admittance or conductance signal received from a volume sensor and a signal received from a pressure sensor and generating a family of pressure-volume loops.

[0021] In some aspects, the techniques described herein relate to a method that includes using the Valsalva maneuver to generate an admittance or conductance signal received from a volume sensor and a signal received from a pressure sensor and generating a family of pressure-volume loops.

[0022] In some aspects, the techniques described herein relate to a method in which determining the right ventricular volume includes V = A * γ * Gb / (γ - Gb), where V is the right ventricular volume, γ is the measured admittance or conductance at infinite volume, and A is a coefficient calibrated from the stroke volume.

[0023] This summary is illustrative and not intended to limit anything in any way. Other aspects of the apparatus or process described herein, features and advantages of the invention will become apparent from the detailed description provided herein in conjunction with the accompanying drawings, and similar reference numbers refer to similar elements.

[0024] The apparatus is described in more detail in the following drawings. The drawings are for illustrative purposes only, and specific features may be used individually or in combination with other features. The drawings are not necessarily drawn to scale. [Brief explanation of the drawing]

[0025] [Figure 1] Figure 1 is a schematic diagram of a pulmonary artery catheter including a conductive sensor system placed inside the heart, according to several embodiments. [Figure 2] Figure 2 is a schematic diagram of the pulmonary artery catheter shown in Figure 1, according to several embodiments. [Figure 3] Figure 3 is a photograph of the pulmonary artery catheter from Figure 1 placed inside the heart of a pig, in several embodiments. [Figure 4] Figure 4 shows X-ray images of the pulmonary artery catheter from Figure 1 placed inside the heart of a pig, according to several embodiments. [Figure 5] Figure 5 is a graph of pressure-volume loop data sets measured under condition A using the pulmonary artery catheter shown in Figure 1, according to several embodiments. [Figure 6] Figure 6 is a graph of pressure-volume loop data sets measured under condition B using the pulmonary artery catheter shown in Figure 1, according to several embodiments. [Figure 7] Figure 7 is a graph of pressure-volume loop datasets measured under condition C using the pulmonary artery catheter shown in Figure 1, according to several embodiments. [Figure 8] Figure 8 is a three-dimensional view of the pulmonary artery catheter of Figure 1, including the dotted outline of the dual electric field admittance measurement in the right ventricle according to several embodiments. [Figure 9]Figure 9 is a graph showing volume versus time determined based on admittance or conductance measured from a sensor of the pulmonary artery catheter, according to several embodiments. [Figure 10] Figure 10 is a graph showing volume versus time determined based on admittance or conductance measured from a sensor of a pulmonary artery catheter, according to several embodiments. [Figure 11] Figure 11 is a graph showing volume versus time determined based on admittance or conductance measured from a sensor of a pulmonary artery catheter, according to several embodiments. [Figure 12] Figure 12 is a graph showing volume versus time determined based on admittance or conductance measured from a sensor of a pulmonary artery catheter, according to several embodiments. [Figure 13] This graph shows total volume versus time using a pulmonary artery catheter in several embodiments. [Modes for carrying out the invention]

[0026] The following is a more detailed description of the concepts and embodiments relating to devices and systems for volume measurement provided by pulmonary artery catheters. Before referring to the drawings that illustrate specific exemplary embodiments in detail, it should be understood that this disclosure is not limited to the details or methodologies described or shown in the description or drawings. It should also be understood that the terms used herein are for illustrative purposes only and should not be considered limiting.

[0027] Referring to the drawings in general, the various embodiments disclosed herein relate to systems and apparatus for measuring right ventricular volume using a pulmonary artery catheter. In some embodiments, the pulmonary artery catheter includes a pressure sensor and a volume sensor arranged along the length of the pulmonary artery catheter. In some embodiments, the volume sensor includes three volume sensors. In some embodiments, all volume sensors are configured to be located in the right ventricle of the heart. In some embodiments, the volume sensor includes a pair of admittance electrodes. In some embodiments, the volume sensor includes a single admittance electrode.

[0028] In some embodiments, a catheter system is used to measure pressure within the heart (for example, to perform right heart catheterization [RHC]), and three pairs of admittance electrodes are provided on the catheter. The admittance electrodes allow the catheter system to significantly increase the information it can derive beyond just pressure measurement. The catheter system provides the ability to determine the simultaneous measurement of right ventricular (RV) volume and RV pressure. This allows physicians to obtain a level of information that was previously impossible. This enhanced diagnostic tool enables the measurement of the right ventricular (RV, or right side of the heart) pressure volume (PV) loop, which provides valuable diagnostic information about the heart in a variety of critical clinical situations. Currently, RHC is needed to help guide the care of patients with severe cardiac dysfunction in conditions such as heart failure (i.e., patients with cardiogenic shock or patients requiring heart transplantation / permanent pump implantation due to cardiac dysfunction) and pulmonary hypertension (i.e., high pressure in the lungs causing right ventricular dysfunction) and other conditions. However, while this information can be useful, it is known that typical catheters or any other widely available diagnostic tools currently cannot directly measure the intensity of cardiac contraction (known as the end-systolic pressure-volume relationship: ESPVR). The ability to obtain this information using the catheter system disclosed herein could change the landscape of clinical care for these patients. Integrating this data into a catheter system would enable the application of advanced measurements for the first time in routine clinical practice, as it allows for the routine measurement of this data. Until now, these types of useful measurements have only been available as research tools. The catheter system disclosed herein could enable widespread extension into clinical practice.

[0029] A better understanding of right ventricular function in the different disease states described above will enable earlier identification of pathological conditions and responses to treatment. This can influence treatment decisions in complex clinical situations for which there is currently no standard or unified approach in the clinical community. To give a concrete example using one of the disease states described above, pulmonary hypertension is a disease with a high mortality rate. There are three classes of FDA-approved drugs that can reduce pressure in the lungs. However, there are no standard parameters or values ​​obtained from right heart catheterization that can reliably assess the cardiac response to these drugs. Often, by the time right heart catheterization pressure readings indicate a "rapid deterioration" in cardiac function, it is too late to implement treatments that may be beneficial to the patient. It is important to be able to identify potential myocardial insufficiency. For example, if the right ventricle does not respond to treatment, it can be a driving force to intensify medical treatment or to begin pursuing a lung transplant (a curative treatment for severe pulmonary hypertension that does not respond to medical treatment). On the other hand, if right ventricular function is improving and myocardial contractility is improving, current treatment can be continued.

[0030] One strength of this innovation is its ability to acquire associated pressure and volume data using the catheter system. Adding the ability to assess the right ventricular PV loop enables simultaneous data acquisition, eliminating the need to place additional catheters (which also require calibration) in the patient, thus avoiding the additional time and risk considered excessive for routine use. Furthermore, pulmonary artery catheters are already routinely used in these patient populations for continuous measurement, and the general form of the catheter system is well-known to clinicians. The addition of the PV loop in the heart allows for the identification of a dysfunctional right ventricle before it becomes too late to intervene. Additionally, the catheter system facilitates further research applications (enabling questions and answers regarding cardiac function in response to different treatments in different disease states).

[0031] Catheter systems can be used in many clinical conditions, including, but not limited to, right ventricular dysfunction in patients with severe heart failure requiring heart transplantation or permanent cardiac pump implantation (also known as left ventricular assist devices or LVADs, for patients with cardiogenic shock), and pulmonary hypertension of various etiologies. In some embodiments, information received from the catheter system allows clinicians to perform the Valsalva maneuver to non-invasively affect cardiac function. Clinically, right ventricular dysfunction is a driving factor for morbidity and mortality in all of these heart diseases. Because the pathophysiology of right ventricular dysfunction is not well understood, all current treatments target left ventricular (LV) dysfunction. Patient benefits could be improved in morbidity and mortality due to a greater understanding of the interaction between right ventricular cavity function, reserve, and the load it pumps (e.g., right ventricular end-systolic elastance and right ventricular effective arterial elastance and their ratios), which is currently not routinely measurable in patients. For example, the treatment of cardiogenic shock is varied, and there is a lack of understanding of when right ventricular recovery is possible. Right ventricular PV loop data in patients with cardiogenic shock can provide crucial clues to distinguish between a dysfunctional right ventricle and one with the potential for recovery. This helps in understanding which patients require curative treatment, including heart transplantation, compared to those who can recover. Similarly, patients with advanced heart failure undergoing LVAD implantation for end-stage heart failure suffer from the inability to predict right ventricular failure as a weakness of this widely used treatment. Several clinical scores and definitions have been developed to define right ventricular failure, and a uniform approach is not used for diagnostic methods that lack reliable predictive models. Finally, a major clinical problem in patients with pulmonary hypertension is right ventricular dysfunction. The ability to assess the right ventricular functional response to current treatment is valuable because current clinical metrics cannot incorporate this, as it is fundamentally difficult to assess right ventricular function by conventional methods (i.e., echocardiography and right heart catheterization only).Right heart catheterization is commonly used in these patient populations, and therefore, it would be beneficial to add the ability to obtain a PV loop to a catheter that is already widely used.

[0032] A prototype has been built and tested specifically for this application. The catheter system features pressure measurement capabilities, supports multiple independent configurations, and allows selection of four electrodes from multiple electrodes on the catheter. This offers a novel feature for simplifying calibration. The prototype incorporates relays, allowing the software to automatically cycle through configurations while selecting the optimal signal. Using this prototype, a study in n=8 pigs completed measurements of the right ventricular PV loop. It was demonstrated that it is possible to administer drugs that affect blood pressure (increasing arterial afterload with phenylephrine), drugs that affect heart rate and contractility (with dobutamine), or drugs that directly suppress cardiac function (inducing myocardial damage using beta-blockers and intracoronary microspheres). The catheter system can detect myocardial responses to these conditions using the RV-PV loop as described above. The inventors used separate catheters simultaneously, a standard research method for obtaining RV-PV loop data, and found that their method exhibits excellent correlation. Finally, to obtain a standard value for right ventricular volume, magnetic resonance imaging (MRI) was performed on all pig hearts and compared with the measured right ventricular volume.

[0033] By incorporating a volume sensor into a pulmonary artery catheter, healthcare providers can acquire simultaneous pressure and volume data using a catheter widely used in clinical practice. Adding the ability to assess the right ventricular pressure-volume loop allows for simultaneous data acquisition without the need to implant additional catheters in patients. The routine use of the right ventricular pressure-volume loop is cumbersome because additional catheters must be calibrated and implanted separately, adding extra time and risk. The ability to assess the right ventricular pressure-volume loop in the heart simplifies the assessment of myocardial contractility and eliminates the need for associated imaging to assess ventricular volume (e.g., cardiac MRI, which requires additional cost, expertise, and time). Furthermore, the pulmonary artery catheter described herein is also useful for research purposes (e.g., to ask and answer questions about cardiac function in various treatments across different disease states).

[0034] As shown in Figure 1, the heart 10 includes a right atrium 14, a tricuspid valve 18, a right ventricle 22, a pulmonary valve 26, and a pulmonary artery 30. The pulmonary artery catheter system 50 includes a catheter 54 configured to be inserted into the heart 10, and a port housing 58 that includes a right ventricular port 62 (e.g., a pressure port), a right atrial port 66 (e.g., a pressure port), a distal pulmonary artery space 70, a balloon port 74, and a volume sensor support 78. In some embodiments, the port housing 58 is a strain relief supporting the right ventricular port 62, the right atrial port 66, the distal pulmonary artery space 70, the balloon port 74, and the volume sensor support 78. For example, the port housing 58 may include plastic overmolding or shrink-fittings that hold the ports in place and allow access to the ports when in use.

[0035] In some embodiments, the right atrial port 66 provides pressure sensing. For example, the lumen of the catheter 54 can be a fluid-filled catheter connected to an opening positioned along the length of the catheter 54, and a pressure transducer or another pressure measuring sensor can be connected to the right atrial port 66 to determine the pressure at the location of the opening.

[0036] In some embodiments, the right ventricular port 62 provides pressure sensing. For example, the lumen of the catheter 54 can be a fluid-filled catheter connected to an opening positioned along the length of the catheter 54, and a pressure transducer or another pressure measuring sensor can be connected to the right ventricular port 62 to determine the pressure at the location of the opening. In some embodiments, the fluid-filled catheter can be replaced with a different sensor type. For example, a micromanometer can be placed in the catheter 54 at a desired position, and a pressure signal can be transmitted via the right ventricular port 62. In some embodiments, multiple pressure sensors can be provided communicating with the right ventricular port 62.

[0037] The volume sensor support 78 is positioned to communicate with volume sensors positioned along the length of the catheter 54. In some embodiments, a first volume sensor 82 is positioned along the catheter 54 so as to be located within the right ventricle 22, a second volume sensor 86 is positioned along the catheter 54 so as to be located within the right ventricle 22, and a third volume sensor 90 is positioned along the catheter 54 so as to be located within the right ventricle 22. In some embodiments, the first volume sensor 82 provides information used to determine the outflow vector, and the third volume sensor 90 provides information used to determine the inflow vector. The inflow and outflow vectors are used to determine the final common right ventricular volume measurement. In some embodiments, the second volume sensor 86 is omitted. In some embodiments, the first volume sensor 82, the second volume sensor 86, and the third volume sensor 90 are used together to determine the inflow and outflow vectors.

[0038] As shown in Figure 2, the first volume sensor 82 is positioned at a distance A from the distal end of the catheter 54. In some embodiments, distance A is between 10 centimeters (10 cm) and 35 centimeters (35 cm). The first volume sensor 82 is positioned along the length of the catheter 54 so that it remains in place in the right ventricle 22 during use.

[0039] In some embodiments, the second volume sensor 86 is spaced at a distance B from the distal end of the catheter 54. In some implementations, distance B is between 12 centimeters (12 cm) and 45 centimeters (45 cm). The second volume sensor 86 is positioned along the length of the catheter 54 so that it is placed in the right ventricle 22 during use. In some embodiments, distance B is greater than distance A.

[0040] In some embodiments, the third volume sensor 90 is spaced at a distance C from the distal end of the catheter 54. In some implementations, distance C is between 14 centimeters (14 cm) and 55 centimeters (55 cm). The third volume sensor 90 is positioned along the length of the catheter 54 so that it is placed in the right ventricle 22 during use. In some embodiments, distance C is greater than distance B.

[0041] In some embodiments, the first volume sensor 82 includes an admittance sensor having two electrodes 1' and 2' spaced apart by a distance D. In some implementations, the distance D is between 1 millimeter (1 mm) and 5 millimeters (5 mm). In some embodiments, electrodes 1' and 2' are positioned on the outer surface of the catheter 54. In some embodiments, electrodes 1' and 2' include a flexible conductive material. In some embodiments, electrodes 1' and 2' include a rigid conductive material. In some embodiments, the first volume sensor 82 includes only one electrode 1'.

[0042] In some embodiments, the second volume sensor 86 includes an admittance or conductance sensor having two electrodes 3' and 4' spaced apart by a distance D. In some implementations, electrodes 3' and 4' are positioned on the outer surface of the catheter 54. In some embodiments, electrodes 3' and 4' include a flexible conductive material. In some embodiments, electrodes 3' and 4' include a rigid conductive material. In some embodiments, the second volume sensor 86 includes only one electrode 3'.

[0043] In some embodiments, the third volume sensor 90 includes an admittance or conductance sensor having two electrodes 5' and 6' spaced apart by a distance D. In some implementations, electrodes 5' and 6' are positioned on the outer surface of the catheter 54. In some embodiments, electrodes 5' and 6' include a flexible conductive material. In some embodiments, electrodes 5' and 6' include a rigid conductive material. In some embodiments, the third volume sensor 90 includes only one electrode 5'.

[0044] In some embodiments, other types of volume sensors may be used. In some embodiments, the volume sensor is fabricated within the catheter 54. In some embodiments, the volume sensor is integrated with the catheter 54. In some embodiments, the volume sensor is flush with the outer surface of the catheter 54 to facilitate insertion. In some embodiments, the volume sensor is attached to the outer surface of the catheter 50 by adhesive. In some embodiments, the pulmonary artery catheter system 50 includes volume sensors in the form of multiple electrodes, and the operator can select which electrodes to use to determine the volume of the right ventricle 22 or another part of the heart 10. As shown in Figure 8, electrical communication between electrodes provides admittance measurements, which are then used to determine the volume. In the context of this application, the term volume sensor may include pairs of conductive electrodes arranged adjacently or spaced apart, three or more electrodes that are equally spaced or unevenly spaced, various volume sensors that do not utilize conductance and / or admittance, etc. The volume sensor provides a signal (fluid, electron, etc.) indicating volume.

[0045] In some embodiments, the first volume sensor 82 is positioned along the catheter 54 such that, upon installation, the first volume sensor 82 is separated from the pulmonary valve 26 by a valve spacing distance E. In some implementations, the third volume sensor 90 is positioned along the catheter 54 such that, upon installation, the third volume sensor 90 is separated from the tricuspid valve 18 by a valve spacing distance E. In some implementations, the valve spacing distance is between 5 millimeters (5 mm) and 20 millimeters (20 mm).

[0046] In some embodiments, the spacing between the first volume sensor 82, the second volume sensor 86, and the third volume sensor 90 along the length of the catheter 54 differs from that described above with respect to the distal tip of the catheter 54. In some embodiments, the second volume sensor 86 is spaced apart from the first volume sensor 82 by an electrode spacing distance F. In some implementations, the third volume sensor 90 is spaced apart from the second volume sensor 86 by an electrode spacing distance F. In some implementations, the electrode spacing distance F is between 20 millimeters (20 mm) and 150 millimeters (150 mm). The first volume sensor 82, the second volume sensor 86, and the third volume sensor 90 are all configured to be positioned within the right ventricle 22 when the pulmonary artery catheter system 50 is placed in the heart 10.

[0047] In some embodiments, the pressure sensor 106 is positioned along the length of the catheter 54 and configured to be located within the right ventricle 22 between the tricuspid valve 18 and the pulmonary valve 26. The pressure sensor 106 is coupled to the right ventricular port 62 and provides pressure information thereto (e.g., via electrical signals, via fluid communication, etc.). In some embodiments, the pressure sensor 106 is positioned between the first volume sensor 82 and the second volume sensor 86. In some embodiments, the pressure sensor 106 is positioned between the second volume sensor 86 and the third volume sensor 90. As described above, the pressure sensor 106 may include remotely detected pressure (e.g., using a fluid-filled catheter and pressure port) or locally detected pressure (e.g., built-in electronic equipment such as a micromanometer).

[0048] In some embodiments, the pulmonary artery catheter system 50 includes additional electronic equipment positioned along the length of the catheter 54 to provide information without the need to implant a second catheter. For example, this may include a thermistor or other temperature sensor, a heater, or other electronic equipment.

[0049] As shown in FIGS. 3 and 4, it has been demonstrated that the pulmonary artery catheter system 50 with the volume sensors arranged as described above can be successfully placed in the heart of a pig.

[0050] As shown in FIGS. 5 - 7, the pressure - volume loop data received from the right ventricular port 62 and the volume sensor port 78 successfully demonstrates the effectiveness of the volume sensors 82, 86, 90. Using the pulmonary artery catheter system 50 including the volume sensors 82, 86, 90, the in - vivo pressure - volume loop data of a pig was measured. The pressure - volume loop and the corresponding right ventricular contractility (E es ) were compared with the baseline for condition A (shown in FIG. 5) including increased E es and decreased afterload, condition B (shown in FIG. 6) including increased E es and increased afterload, and condition C (shown in FIG. 7) including decreased E es and decreased afterload. The effective arterial elastance (E a ) is a method of estimating afterload by measuring the slope of the line on the pressure - volume loop. The line extends from the end - diastolic pressure - volume point to its end - systolic pressure - volume point. E a is also known as the ratio of the end - systolic pressure to its stroke volume (SV). The combined ratio of E es , E a , and E es / E a can be determined based on the sensor information from the pulmonary artery catheter system 50 and can be used by clinicians for diagnosis.

[0051] The pulmonary artery catheter system 50 can be used in many clinical conditions, including, but not limited to, right ventricular dysfunction in heart failure patients requiring heart transplantation or permanent / temporary cardiac pump implantation (e.g., left ventricular assist device or LVAD for patients with cardiogenic shock), patients with various etiologies of pulmonary hypertension, and patients with tricuspid regurgitation for determining whether they are candidates for tricuspid valve repair or replacement. Clinically, right ventricular dysfunction is a driving factor for morbidity and mortality in all of these cardiac diseases. Current treatments are directed towards left ventricular dysfunction because the pathophysiology of right ventricular dysfunction is not well understood. The advantages of using the pulmonary artery catheter system 50 include the potential improvement in morbidity and mortality in composite patients due to a greater understanding of right ventricular chamber function, reserve, and interactions. Current systems do not provide right ventricular chamber volume in any form. For example, the treatment of cardiogenic shock is varied, and there is a lack of understanding of when right ventricular recovery is possible. Right ventricular pressure-volume loop data in patients with cardiogenic shock can provide crucial clues to distinguish between dysfunctional right ventricles and those with the potential for recovery. This helps in understanding which patients require curative treatment, including heart transplantation, compared to those who can recover. Similarly, patients with advanced heart failure undergoing LVAD implantation for end-stage heart failure are troubled by the inability to predict right ventricular failure in this widely used treatment. Several clinical scores and definitions have been developed to define right ventricular failure, and a uniform approach is not used for diagnostic methods lacking reliable predictive models. Right ventricular dysfunction is a major clinical problem in patients with pulmonary hypertension. The ability to assess the right ventricular functional response to current treatment is valuable, as current clinical metrics cannot incorporate this because it is fundamentally difficult to assess right ventricular function by conventional methods (e.g., echocardiography and RHC alone). Right heart catheterization is commonly used in these patient populations, and therefore, adding the ability to obtain the right ventricular loop on a catheter that is already widely used would be beneficial. Tricuspid regurgitation is another application.Due to a lack of understanding of the relationship between right ventricular systolic function and the afterload it pumps, it is currently unclear which patients may benefit from surgical or percutaneous valve repair or replacement. In cases where low-resistance right atrial leakage is significant to continued right ventricular function, removal of tricuspid regurgitation in this patient subset may result in acute right ventricular failure. In contrast, in patients with access to the right ventricular pressure-volume loop and derived E. es and E a Therefore, even when it is predicted that invasive cessation of tricuspid regurgitation is safe, some patients may refuse invasive treatment for tricuspid regurgitation due to concerns that it may lead to right ventricular dysfunction.

[0052] The pulmonary artery catheter system 50 includes pressure sensing and supports multiple independent configurations (e.g., using a subset of available volume sensors). In some embodiments, it includes more than six electrodes or fewer than six electrodes. In some embodiments, it includes more than three volume sensors or fewer than three volume sensors. The pulmonary artery catheter system 50 includes features to simplify calibration. For example, the pulmonary artery catheter system 50 includes relays so that the associated software can automatically cycle through configurations to select the best signal. The inventors have completed a study in pigs using the pulmonary artery catheter system 50 to measure the pressure-volume loop of the right ventricle under different hemodynamic conditions (shown in Figures 5-7). The pulmonary artery catheter system 50 can detect myocardial responses to these conditions using the pressure-volume loop of the right ventricle as described above. In some embodiments, the pulmonary artery catheter system 50 can be configured to couple a volume sensor to right atrial pressure for the atrial pressure-volume loop.

[0053] In some embodiments, the first volume sensor 82, the second volume sensor 86, and the third volume sensor 90 measure admittance or conductance signal (G b) provides. As shown in Figure 8, the exemplary first volume sensor 82, second volume sensor 86, and third volume sensor 90 include six electrodes that generate an electric field that completely fills the volume. In some embodiments, the right ventricular volume is given by V = A * γ * G b / (γ-G b ) is determined as follows, where V is the volume, γ is the admittance or conductance measured at an infinite volume, and A is a coefficient calibrated from the stroke volume. In some embodiments, γ is measured at σ = 0.8333 S / m. Then, using (SV, γ), A = ρL 2 Calibrate it. Next, measurements are taken for the last two beats of exhalation (G bES =min(G b ) 7 points average, G bED =full(G b In the examples shown in Figures 9-12, SV = 45.92 mL, and A = SV / (γ*G bED / (γ-G bED )-γ*G bES / (γ-G bES )), the measured outflow rate γ = 25 mS, and the measured inflow rate γ = 27 mS. In some embodiments, V = A * γ * |Y| / (γ - |Y|). In some embodiments, G b This is determined based on the two fields shown in Figure 8, G b =G bA (First admittance or conductance field) + G bB (This is the second admittance or conductance field.) Using the system and method described above, the real-time volumetric measurements shown in Figure 13 were determined.

[0054] For the purposes of this specification, specific advantages and novel features of the aspects and configurations of this disclosure are described herein. The methods, systems, and apparatus described herein should not be construed as limiting in any sense. Rather, this disclosure covers all novel and non-obvious features and aspects of the various disclosed aspects, both individually and in various combinations and partial combinations. The disclosed methods, systems, and apparatus are not limited to any particular aspects, features, or combinations thereof, and the disclosed methods, systems, and apparatus do not require the existence of any one or more particular advantages or the resolution of any problem.

[0055] While the diagrams and descriptions may show a specific order of steps in the method, unless otherwise specified above, the order of such steps may differ from that shown and described. Also, unless otherwise specified above, two or more steps may be performed simultaneously or partially simultaneously. Such variations may vary, for example, depending on the selected software and hardware system and the designer's choices. All such variations are within the scope of this disclosure. Similarly, software implementations of the described methods can be achieved using standard programming techniques with rule-based logic and other logic to perform various connection, processing, comparison, and decision steps.

[0056] All features and / or steps of any method or process disclosed herein (including the accompanying claims, abstract, and drawings) may be combined in any combination, except for any combination in which at least some of such features and / or steps are mutually exclusive. The claimed features extend to any novel features or any novel combination of features disclosed herein (including the accompanying claims, abstract, and drawings), or any novel steps of any method or process disclosed herein (including the accompanying claims, abstract, and drawings).

[0057] Where used herein and in the appended claims, the singular forms “a,” “an,” and “the” refer to multiple objects unless otherwise explicitly indicated by the context. Herein, ranges may be described as “about” a certain value and / or “about” another particular value. Where such ranges are expressed, another aspect includes a range from a certain value and / or another particular value. Similarly, where a value is expressed as an approximation by the use of the antecedent “about,” it will be understood that a particular value forms another aspect. Furthermore, it will be understood that each endpoint of a range is important both in relation to other endpoints and independently of other endpoints. The terms “about” and “approximately” are defined as “close to” as understood by those skilled in the art. In one non-limiting aspect, these terms are defined as within 10%. In another non-limiting aspect, these terms are defined as within 5%. In yet another non-limiting aspect, these terms are defined as within 1%.

[0058] As used herein, terms such as “coupled” and “connected” mean joining two members directly or indirectly to one another. Such joining may be fixed (e.g., permanent) or movable (e.g., removable or detachable). Such joining may be achieved by two members or two members and any additional intermediate members being formed integrally with each other as a single, unified entity, or by two members or two members and any additional intermediate members being attached to each other. Where “coupled” or a variation thereof is modified by an additional term (e.g., “directly coupled”), the above general definition of “coupled” is modified by the plain language meaning of the additional term (e.g., “directly coupled” means joining two members without a separate intervening member), resulting in a narrower definition than the above general definition of “coupled”. Such joining may be mechanical, electrical, or fluid. For example, the statement that circuit A is "coupled" to circuit B may mean that circuit A communicates directly with circuit B (i.e., without an intermediary) or that it communicates indirectly with circuit B (e.g., through one or more intermediaries).

[0059] In the following explanation, specific terms are used for convenience only and are not limiting. The words “right,” “left,” “lower,” and “upper” specify directions within the referenced drawing. The words “inner” and “outer” refer to directions toward and away from the geometric center of the described feature or device, respectively. The words “distal” and “proximal” refer to directions as interpreted in the context of the described item, and for the instruments described herein, generally, “proximal” refers to a position closer to the practitioner using such an instrument, and “distal” refers to a position further away from the practitioner. The terminology includes the words listed above, their derivatives, and words with similar meanings.

[0060] Throughout this specification and its claims, the word “comprise” and variations such as “comprising” and “comprises” mean “including but not limited to,” and are not intended to exclude, for example, other additives, ingredients, elements, or processes. “Exemplary” means “an example of,” and is not intended to represent a preferred or ideal embodiment. “Such as” is used for illustrative purposes only, not in a restrictive sense.

[0061] All means or processes plus functional elements in the following claims are intended to include any structures, materials, or actions for performing a function in combination with other claimed elements specifically claimed. The description of the invention is presented for illustrative and explanatory purposes, but is not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the invention.

Claims

1. Catheter and, A port housing connected to the catheter, Right ventricular port, Right atrial port, Distal space of the pulmonary artery, Balloon port, and Volume Sensor Support A port housing that supports, Multiple volume sensors are arranged along the length of the catheter and communicate with the volume sensor support, A pulmonary artery catheterization system equipped with [a specific feature / equipment].

2. The aforementioned multiple volume sensors are A first volume sensor configured to be positioned in the right ventricle, A second volume sensor configured to be positioned in the right ventricle, A third volume sensor configured to be positioned in the right ventricle, A pulmonary artery catheter system according to claim 1, comprising:

3. The pulmonary artery catheter system according to claim 1, wherein the plurality of volume sensors are used to determine the inflow vector and the outflow vector.

4. The aforementioned multiple volume sensors are A first volume sensor is positioned at a first distance from the distal tip of the catheter, A second volume sensor is positioned at a second distance from the distal tip of the catheter, A third volume sensor is positioned at a third distance from the distal tip of the catheter. Equipped with, The pulmonary artery catheter system according to claim 1, wherein the second distance is greater than the first distance, and the third distance is greater than the second distance.

5. The first volume sensor is spaced 20 mm to 150 mm from the second volume sensor. The pulmonary artery catheter system according to claim 4, wherein the second volume sensor is spaced 20 mm to 150 mm apart from the third volume sensor.

6. The pulmonary artery catheter system according to claim 5, wherein the distance between the first volume sensor and the second volume sensor is equal to the distance between the second volume sensor and the third volume sensor.

7. The pulmonary artery catheter system according to claim 1, wherein each of the plurality of volume sensors includes a conductive sensor.

8. The pulmonary artery catheter system according to claim 7, wherein each conductive sensor includes an electrode pair.

9. The pulmonary artery catheter system according to claim 7, wherein each conductive sensor is formed from a flexible conductive material.

10. The pulmonary artery catheter system according to claim 7, wherein each conductive sensor is formed from a rigid conductive material.

11. The pulmonary artery catheter system according to claim 1, further comprising a pressure sensor positioned along the length of the catheter and configured to be located in the right ventricle, which provides a signal indicating pressure to the right ventricular port.

12. The pulmonary artery catheter system according to claim 11, wherein the pressure sensor includes a pressure opening that utilizes a fluid-filled catheter.

13. The pulmonary artery catheter system according to claim 11, wherein the pressure sensor includes a micromanometer.

14. The pulmonary artery catheter system according to claim 11, wherein the signals received from the right ventricular port and the volume sensor support are configured to generate a pressure-volume loop in the right ventricle.

15. A catheter that defines the distal tip and the proximal port housing, The right ventricular port connected to the proximal port housing, The right atrial port connected to the proximal port housing, The distal space of the pulmonary artery connected to the proximal port housing, A balloon port connected to the proximal port housing, A volume sensor support coupled to the proximal port housing, A pressure sensor is positioned along the length of the catheter and configured to be located in the right ventricle, and provides a signal indicating the pressure to the right ventricular port. A first admittance sensor is positioned along the length of the catheter, A second admittance sensor is positioned along the length of the catheter, A third admittance sensor positioned along the length of the catheter and A pulmonary artery catheter system comprising, At least two of the first admittance sensor, the second admittance sensor, or the third admittance sensor are configured to be located in the right ventricle of the heart. Pulmonary artery catheterization system.

16. The pulmonary artery catheter system according to claim 15, wherein each of the first admittance sensor, the second admittance sensor, and the third admittance sensor includes a pair of conductive electrodes.

17. Inserting a pulmonary artery catheter system into the heart, Determining the right ventricular volume based on admittance or conductance signals received from a volume sensor of the pulmonary artery catheter system located in the right ventricle of the heart. Determining the right ventricular pressure based on the signal received from the pressure sensor of the pulmonary artery catheter system located in the right ventricle, and To generate a pressure-volume loop of the right ventricle based on the determined volume and pressure, A method that includes this.

18. Based on the admittance or conductance signal received from the volume sensor and the signal received from the pressure sensor, the effective arterial elastance (E ａ ), ventricular contractility (E ｅｓ ), and the binding ratio (E ｅｓ / E ａ The method according to claim 17, further comprising determining ).

19. The method according to claim 17, wherein inferior vena cava occlusion is used to generate the admittance or conductance signal received from the volume sensor and the signal received from the pressure sensor in order to generate a family of pressure-volume loops.

20. The method according to claim 17, wherein the Valsalva method is used to generate the admittance or conductance signal received from the volume sensor and the signal received from the pressure sensor in order to generate a family of pressure-volume loops.

21. The right ventricular volume is determined by V = A * γ * G ｂ / (γ-G ｂ The method according to claim 17, wherein V is the right ventricular volume, γ is the measured admittance or conductance at infinite volume, and A is a coefficient calibrated from stroke volume.

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