A system and method utilizing sense channels connected to multiple electrodes.

Abstract

Information from sense channels connected to multiple electrodes, in addition to information from a sense channel connected to a single electrode, provides additional functionality to the connected device. [Solution] The computer implementation method includes measuring a first electrode impedance signal associated with a first electrode using a first sense channel. The method further includes measuring a second electrode impedance signal associated with at least a second electrode and a third electrode using a second sense channel, wherein the second and third electrodes are electrically connected to each other but not to the first electrode. The method further evaluates tissue contact / proximity based on the first electrode impedance signal and the second electrode impedance signal.

Description

Technical Field

[0001] (Background) Intracardiac electrophysiology devices typically include a catheter having a proximal end and a distal end that includes a plurality of electrodes. Signals sensed by the plurality of electrodes are utilized by an electrophysiology system to perform a number of functions including determining the position of the electrodes within the patient's body and sensing electrograms associated with adjacent heart tissue. This information can be used to understand the electrical activity of the heart and to identify the origin and pathway of abnormal heart rhythms such as arrhythmias.

[0002] Software such as the EnsiteX cardiac mapping system is an example of a system that can be used with a plurality of different types of catheters to provide EP mapping. Different types of catheter devices have different electrode configurations. For example, in some devices, at least some of the electrodes are individually connected to sense channels and at least some of the electrodes are connected together such that the sense channels are connected to a plurality of electrodes.

[0003] It would be beneficial to be able to utilize information from sense channels connected to a plurality of electrodes in addition to information from sense channels connected to a single electrode to provide additional functionality to the connected device.

Summary of the Invention

Means for Solving the Problems

[0004] The present invention relates to three different methods of utilizing information received from sense channels connected to multiple electrodes. One aspect relates to determining tissue contact / proximity using impedance signals measured by electrodes, including impedance signals measured by sense channels connected to multiple electrodes. A second aspect relates to detecting the deployment status of the distal end of a catheter based on received stereotactic signals measured by sense channels, including sense channels connected to multiple electrodes. A third aspect relates to verifying that sense channels are properly connected (either in hardware or software) to generate electromorphic signals based on signals received from electrodes located on the same spline. This method relies on both impedance signals measured by each sense channel and position signals measured by each sense channel, including sense channels connected to multiple electrodes.

[0005] In some embodiments, the techniques described herein relate to a computer-implemented method for evaluating tissue contact of a plurality of electrodes located on a medical device, the method comprising: measuring a first electrode impedance signal associated with a first electrode using a first sense channel; measuring a second electrode impedance signal associated with at least a second electrode and a third electrode using a second sense channel, wherein the second and third electrodes are electrically connected to each other but not to the first electrode; and evaluating tissue contact / proximity based on the first electrode impedance signal and the second electrode impedance signal.

[0006] In some embodiments, the techniques described herein relate to computer implementation methods, wherein evaluating tissue contact / proximity further includes combining a first electrode impedance signal and a second electrode impedance signal to obtain a combined electrode impedance signal, and comparing the combined electrode impedance signal with a baseline value to determine tissue contact / proximity.

[0007] In some embodiments, the techniques described herein relate to computer implementation methods, wherein comparing the aggregated electrode impedance signal to a baseline value includes comparing the aggregated electrode impedance signal to a threshold, and tissue contact is detected when the aggregated electrode impedance signal is greater than the threshold.

[0008] In some embodiments, the technology described herein relates to a computer implementation method, wherein the threshold is selected to represent that both the first electrode and at least one of the second and third electrodes are in contact with tissue.

[0009] In some embodiments, the technology described herein relates to a computer implementation method, wherein the threshold is selected to represent that the first electrode, or at least one of the second and third electrodes, is in contact with tissue.

[0010] In some embodiments, the techniques described herein relate to computer implementation methods, wherein combining a first electrode impedance signal and a second electrode impedance signal to form an aggregate electrode impedance signal includes scaling the second electrode impedance signal to a value representing a single electrode impedance signal.

[0011] In some embodiments, the technology described herein relates to a computer implementation method, wherein scaling a second electrode impedance signal includes multiplying the second electrode impedance signal by the number of electrodes connected to the second sense channel.

[0012] In some embodiments, the techniques described herein relate to computer implementation methods, and the combination of a first electrode impedance signal and a second electrode impedance signal further includes adding the first electrode impedance signal to a scaled second electrode impedance signal and dividing by the number of sense channels.

[0013] In some embodiments, the techniques described herein relate to computer implementation methods, and evaluating tissue contact / proximity further includes: comparing a first electrode impedance signal to a first baseline value to detect a first change in impedance; comparing a second electrode impedance signal to a second baseline value to detect a second change in impedance; scaling the second change in impedance to a value representing a single electrode impedance measurement; combining the first change in impedance and the scaled second change in impedance; and evaluating tissue contact / proximity based on a comparison of the combined change in impedance with a threshold.

[0014] In some embodiments, the techniques described herein relate to computer implementation methods, wherein scaling a second change in impedance includes multiplying the second change in impedance by the number of electrodes connected to a second sense channel.

[0015] In some embodiments, the technology described herein relates to a computer implementation method in which a first electrode, a second electrode, and a third electrode are located on a single spline.

[0016] In some embodiments, the technology described herein further comprises a computer implementation method that generates an output indicating tissue contact / proximity of a spline based on a measured first electrode impedance signal and a measured second electrode impedance signal.

[0017] In some aspects, the technology described herein relates to a computer implementation method for determining the deployment state of an electrode assembly located at the distal end of a catheter having a plurality of splines and a plurality of electrodes on each spline, the method comprising: calculating the position of a first electrode located on each spline based on a first impedance-based positioning signal received by a first sense channel for each spline; calculating the combined position of at least a second electrode and a third electrode located on each spline based on a second impedance-based positioning signal received by a second sense channel for each spline; and determining the deployment state of the electrode assembly based on the position of the first electrode and the combined position of at least a second electrode and a third electrode.

[0018] In some embodiments, the technology described herein relates to a computer mounting method, wherein the deployment states of the electrode assembly include a low-profile state, a basket-profile state, and a flower-profile state.

[0019] In some embodiments, the technology described herein relates to a computer-aided mounting method, wherein determining the deployment state of an electrode assembly further includes, for each spline, calculating a vector between the position of a first electrode and the combined position of at least a second and a third electrode, and determining the deployment state based on the calculated vector for each of a plurality of splines.

[0020] In some embodiments, the techniques described herein relate to a computer implementation method, further comprising: summing vectors calculated for each of a plurality of splines to generate a total vector; comparing the total vector with a unit vector; and determining the deployment state of the electrode assembly based on the comparison between the total vector and the unit vector.

[0021] In some embodiments, the technology described herein relates to a computer implementation method, wherein the unit vector is the unit normal vector of a plane defined to best fit the position of a first electrode associated with each spline, a plane defined to best fit the combined position of a second and third electrode associated with each spline, or a plane defined to best fit both the position of the first electrode associated with each spline and the combined position of the second and third electrodes.

[0022] In some embodiments, the techniques described herein relate to a computer implementation method in which a total vector is compared to a unit vector using a dot product function, and the dot product output is used to determine the deployment state of the distal end of the catheter.

[0023] In some embodiments, the technology described herein relates to a computer-aided implementation method, further comprising: calculating a second vector between the positions of a first electrode on adjacent splines; and determining an implementation state based on the vector calculated for each of a plurality of splines and the second vector calculated between the positions of the first electrode on adjacent splines.

[0024] In some embodiments, the techniques described herein relate to a computer implementation method for determining a suitable pin jack connection sequence for connecting to a plurality of electrodes located at the distal end of a medical device, the method comprising: measuring an electrode impedance signal associated with each of the plurality of sense channels; determining a position / combined position associated with each of the plurality of sense channels based on an impedance-based localization signal measured by each sense channel, the position / combined position corresponding to an electrode or group of electrodes connected to each of the plurality of sense channels; organizing the plurality of sense channels into a first group of sense channels and a second group of sense channels based on the measured electrode impedance signals; pairing each sense channel in the first group with the nearest sense channel among the sense channels in the second group based on the determined position / combined position of each of the plurality of sense channels; and measuring an electrodynamic diagram (EGM) signal based on the pairing of each sense channel in the first group with the sense channels in the second group.

[0025] In some embodiments, the technology described herein relates to a computer implementation method, wherein at least some of the sense channels are connected to a single electrode located on an electrode assembly located at the distal end of a medical device, and at least some of the sense channels are connected to a plurality of electrodes located on an electrode assembly located at the distal end of a medical device.

[0026] In some embodiments, the techniques described herein relate to a computer implementation method in which a measured electrode impedance signal associated with a sense channel connected to a single electrode is greater than a measured electrode impedance signal associated with a sense channel connected to multiple electrodes.

[0027] In some aspects, the technology described herein relates to a computer-implemented method, wherein an electrode assembly located at a distal end of a medical device includes a plurality of splines, each spline having a plurality of electrodes, at least some of the sense channels being connected to a single electrode on each spline and at least some of the channels being connected to a plurality of electrodes on the same spline.

[0028] In some aspects, when a program is executed by a computer, there is provided a computer program product including instructions for causing the computer to perform the method described above.

[0029] In some aspects, when executed by a processor, there is provided a computer-readable medium storing instructions for causing the processor to perform a method for evaluating tissue contact for a plurality of electrodes located on a medical device. The method includes measuring a first electrode impedance signal associated with a first electrode using a first sense channel, and measuring a second electrode impedance signal associated with at least a second electrode and a third electrode using a second sense channel, wherein the second electrode and the third electrode are electrically connected to each other but not electrically connected to the first electrode, and evaluating tissue contact / proximity based on the first electrode impedance signal and the second electrode impedance signal.

[0030] In some embodiments, a computer-readable medium is provided that, when executed by a processor, stores instructions causing the processor to perform a method for evaluating the tissue contact of a plurality of electrodes located on a medical device. This method includes: calculating the position of a first electrode located on each spline with respect to each spline based on a first impedance-based localization signal received by a first sense channel; calculating the combined position of at least a second and a third electrode located on each spline with respect to each spline based on a second impedance-based localization signal received by a second sense channel; and determining the deployment state of an electrode assembly based on the position of the first electrode and the combined position of at least a second and a third electrode.

[0031] In some embodiments, a computer-readable medium is provided that, when executed by a processor, stores instructions causing the processor to perform a method for evaluating tissue contact of multiple electrodes located on a medical device. The method includes measuring an electrode impedance signal associated with each of the multiple sense channels; determining a position / combined position associated with each of the multiple sense channels based on an impedance-based localization signal measured by each sense channel, the position / combined position corresponding to an electrode or group of electrodes connected to each of the multiple sense channels; and organizing the multiple sense channels into a first group of sense channels and a second group of sense channels based on the measured electrode impedance signals. The method further includes pairing each sense channel in the first group with the nearest sense channel in the second group based on the determined position / combined position of each of the multiple sense channels. A bipolar electromagnetism (EGM) signal is measured based on the pairing of each sense channel in the first group with a sense channel in the second group. [Brief explanation of the drawing]

[0032] [Figure 1]This is a schematic diagram of a system including a medical device for insertion into a patient, which is configured to interact with an electrode located at the distal end of the medical device.

[0033] [Figure 2A] These are isometric views of the distal end of the medical device in the first and second configurations, where the distal end of the medical device includes multiple splines and multiple electrodes on each spline. [Figure 2B] These are isometric views of the distal end of the medical device in the first and second configurations, where the distal end of the medical device includes multiple splines and multiple electrodes on each spline.

[0034] [Figure 3] A block diagram of a first sense channel connected to a first electrode and a second sense channel connected to multiple electrodes.

[0035] [Figure 4] A flowchart illustrating the steps performed by the tissue contact module to assess tissue contact / proximity based on signals received from the first and second sense channels.

[0036] [Figure 5A] A flowchart illustrating the steps performed by the tissue contact module to evaluate tissue contact / proximity based on local electrode impedance signals received from the first and second sense channels. [Figure 5B] A flowchart illustrating the steps performed by the tissue contact module to evaluate tissue contact / proximity based on local electrode impedance signals received from the first and second sense channels.

[0037] [Figure 6]A flowchart illustrating the steps performed by a shape detection module to detect the shape of the distal end of a medical device based on impedance-based localization signals received from multiple first channels and multiple second channels.

[0038] [Figure 7] A flowchart illustrating in more detail the steps performed by a shape detection module to detect the shape of the distal end of a medical device based on impedance-based localization signals received from multiple first channels and multiple second channels.

[0039] [Figure 8A] This is an isometric view of the distal end of the medical device in the first and second configurations, showing the vectors created by the shape detection module based on impedance-based localization signals received from multiple first channels and multiple second channels. [Figure 8B] This is an isometric view of the distal end of the medical device in the first and second configurations, showing the vectors created by the shape detection module based on impedance-based localization signals received from multiple first channels and multiple second channels.

[0040] [Figure 9] A graph showing the values ​​generated based on the steps shown in Figure 7, and the corresponding shape of the distal end of the medical device.

[0041] [Figure 10] A flowchart illustrating the steps performed by the pinjack detection module to pair sense channels as needed to generate a bipolar potential diagram pair. [Modes for carrying out the invention]

[0042] Figure 1 is a schematic depiction of a system 100 including a medical device 102 for insertion into a patient. The medical device 102 includes a handle 103 and a shaft 106 having a proximal end 104 and a distal end 108. An electrode assembly 109 is located at the distal end 108 of the shaft 106 and includes multiple electrodes (shown in more detail in Figures 2A and 2B). In some embodiments, the electrode assembly 109 is a basket composed of multiple individual splines, each spline containing multiple electrodes. Multiple wires connect the electrodes to the handle 103. A cable 111 is connected to the handle 103 and includes multiple pins for interfacing the handle 103 with an input socket 110. In this way, electrical signals sensed by the multiple electrodes are transmitted to the handle 103 and then to a drive / sensing circuit 112 and a computer system 116 via the input socket 110. As will be described in more detail below, in some examples, a subset of electrodes included as part of the electrode assembly 109 is connected together (i.e., multiple electrodes are connected in parallel with each other), while other electrodes are connected individually. As a result, a subset of multiple pins associated with cable 111 is connected to multiple electrodes, while another subset of multiple pins associated with cable 111 is connected to individual electrodes. Each of the multiple pins is connected to a sense channel associated with the drive / sensing circuit 112 (described in more detail in Figure 3). As will be described in more detail below, although a subset of the channel is connected to multiple electrodes and a subset of the channel is connected to individual electrodes, useful information can be obtained from both and is available for a variety of functions, including tissue contact / proximity, shape detection of the electrode assembly 109, and / or pin jack verification (i.e., verifying that the multiple pins associated with cable 111 are connected to the appropriate input sockets 110).

[0043] The computer system 116 is configured to receive signals provided by the drive / sensing circuit 112 and to communicate with the ablation generator 114, the ECG monitor 128, the input / output device 134, and the display device 132. Furthermore, the computer system 116 includes a central processing unit (CPU) 120 and memory / storage device 118, the CPU 120 executing instructions stored in the storage device 118 to perform various functions and operations described herein, including the tissue contact module 122, the shape detection module 124, the pin jack detection module 126, and the localization and navigation system 130. The sensed signals received from the drive / sensing circuit 112 may include one or more of the following: electrode impedance signals (i.e., tissue impedance signals), electromorphic diagram (EGM) signals, and / or impedance-based localization signals. Each of these signals may be monitored with respect to both sense channels connected to a single electrode and sense channels connected to multiple electrodes. The computer system 116 utilizes the signals received from the drive / sensing circuit 112 for various functions, including locating / navigating the electrode assembly 109 through the patient's body 101, detecting tissue contact / proximity between the electrode assembly 109 and adjacent tissue, pin jack verification (verifying that multiple pins associated with the cable 111 are connected to the correct input socket 110), and shape detection (for example, in the case of an electrode assembly 109 containing multiple splines, the multiple splines may be arranged in a low-profile shape, basket geometry, or flower geometry). Each of these functions utilizes information from a sense channel connected to a single electrode and information from sense channels connected to multiple electrodes, as will be described in more detail below.

[0044] The output generated by the computer system 116 may be displayed to the technician / user via the display device 132. Similarly, the technician / user may provide input to the computer system via the input / output device 134.

[0045] Figures 2A and 2B are isometric views of the electrode assembly 109 of the medical device 102 in a first and second configuration. The electrode assembly 109 is located at the distal end of the shaft 106 and, in this embodiment, is guided by a guidewire 300 that extends into the inner part of the electrode assembly and through the distal cap 306. The electrode assembly 109 consists of a plurality of splines 302a, 302b, 302c, 302d, and 302e (collectively, “spline 302”), each spline 302 having its proximal end connected to the shaft 106 and its distal end connected to the distal cap 306. The electrode assembly 109 includes a plurality of electrodes located on each spline 302. For example, spline 302a includes electrodes 304a1, 304a2, 304a3, and 304a4; spline 302b includes electrodes 304b1, 304b2, 304b3, and 304b4; spline 302c includes electrodes 304c1, 304c2, 304c3, and 304c4; spline 302d includes electrodes 304d1, 304d2, 304d3, and 304d4; and spline 302e includes electrodes 304e1, 304e2, 304e3, and 304e4. In other examples, each of the multiple splines may include fewer or more electrodes.

[0046] In one embodiment, the first, second, and fourth electrodes of each spline are connected together. For example, with respect to spline 302a, electrodes 304a1, 304a2, and 304a4 are connected to a single sense channel, and electrode 304a3 is connected to individual sense channels. In this example, multiple electrodes on the other splines 302b, 302c, 302d, and 302e are each connected in the same configuration. This electrode configuration utilizes a total of 10 sense channels. A first subset of sense channels is connected to multiple electrodes. For example, the sense channels of the first subset would include a first channel connected to electrodes 304a1, 304a2, and 304a4; a second channel connected to electrodes 304b1, 304b2, and 304b4; a third channel connected to electrodes 304c1, 304c2, and 304c4; a fourth channel connected to electrodes 304d1, 304d2, and 304d4; and a fifth channel connected to electrodes 304e1, 304e2, and 304e4. The sense channels of the second subset are each connected to individual electrodes. For example, the sixth channel is connected to electrode 304a3, the seventh channel to electrode 304b3, the eighth channel to electrode 304c3, the ninth channel to electrode 304d3, and the tenth channel to electrode 304e3. In this example, a total of 10 sense channels are used, 5 of which are connected to multiple electrodes and 5 are connected to individual electrodes.

[0047] In the embodiment shown in Figure 2A, the electrode assembly 109 has a basket configuration in which the distal cap 306 is located at a certain distance from the proximal end of the electrode assembly 109. In the embodiment shown in Figure 2B, the electrode assembly 109 has a flower configuration in which the distal cap 306 is located adjacent to the proximal end of the electrode assembly 109. For the types of electrode assembly 109 shown in Figures 2A and 2B, another type of configuration is described as a low-profile configuration in which the distal cap 306 is located as far as possible from the proximal end, and the splines 302a to 302e are positioned in a low profile to allow the electrode assembly 109 to fit within the sheath. As will be described in more detail below, the method of detecting the configuration of the electrode assembly 109 may be useful to technicians / physicians.

[0048] Figure 3 is a block diagram of the drive / sensing circuit 112, showing a first sense channel 400a connected to a first electrode 304a3 and a second sense channel 400b connected to a plurality of electrodes including electrodes 304a1, 304a2, and 304a4. In this example, the drive / sensing circuit 112 includes a drive circuit 402 configured to supply a constant current source to the plurality of electrodes via a transformer 404, with node N1 connected to electrode 304a3 and node N2 connected to the plurality of electrodes 304a1, 304a2, and 304a4.

[0049] The first sense channel 400a includes a first operational amplifier 406a having a first input (e.g., a non-inverting input) connected to electrode 304a3 and a second input (e.g., an inverting input) connected to a reference node (e.g., a 408). In some examples, the reference electrode 408 is located on the same catheter as electrode assembly 109 (e.g., the reference electrode may be a shaft electrode), on a separate catheter, or attached as a surface patch electrode on the patient's skin. The second sense channel 400b includes a second operational amplifier 406b having a first input (e.g., a non-inverting input) connected to a plurality of electrodes, including electrodes 304a1, 304a2, and 304a4 in this example, and a second input (e.g., an inverting input) connected to a reference node (e.g., reference electrode 408). In this way, the first sense channel measures the voltage signal sensed by electrode 304a3, and the second sense channel measures the voltage signals sensed by electrodes 304a1, 304a2, and 304a4. As shown in Figure 3, electrodes 304a1, 304a2, and 304a4 are connected in parallel to each other, and the sensed voltage reflects this connection configuration.

[0050] The outputs generated by the first operational amplifier 406a and the second operational amplifier 406b are supplied to the sense circuit 412 and the synchronous demodulator 412, which filter and demodulate the signals sensed in each channel. In the example shown in Figure 3, each sense channel 400a, 400b can measure an electrode impedance signal 414, a potential diagram (EGM) signal 416, and an impedance-based localization signal 418. The synchronous demodulator 412 works to filter or separate specific signals from each other and from background noise signals, based on knowledge of the frequencies of each signal. For example, the electrode impedance signal is measured in response to a drive current supplied by the drive circuit 402 at a predetermined frequency, and the synchronous demodulator filters the measured response to the drive current by multiplying the received signal, including other signals and background noise, by a signal having the same frequency and phase (or a predetermined phase offset) as the drive current. It should be noted that additional components not shown here, such as analog-to-digital converters (ADCs) and switches, may be required to process the monitored signals.

[0051] The electrode impedance signal 414 is measured in response to a constant current supplied by the drive circuit 402. The electrode impedance signal 414 can be determined by the voltage measured by each sense channel, combined with knowledge of the current supplied by the drive circuit 402. The electrode impedance signal relates to the impedance "seen" in the region adjacent to the electrode (or multiple electrodes), and can be used to detect tissue contact / proximity because the impedance seen by the electrode decreases as the electrode comes into contact with tissue (this is due to the fact that tissue exhibits a higher impedance than the blood pool). As detailed below, the measured electrode impedance signal associated with a sense channel connected to a single electrode differs from the measured electrode impedance signal associated with a sense channel connected to multiple electrodes due to the multiple electrodes being connected in a parallel configuration. Figures 4 and 5A, 5B illustrate in more detail how the measured electrode impedance signals 414 associated with both a sense channel connected to a single electrode and a sense channel connected to multiple electrodes can be used to determine tissue contact / proximity.

[0052] The impedance-based localization signal 418 refers to a measurement signal used to locate electrodes within the body. In some embodiments, the localization and navigation system 130 (shown in Figure 1) includes multiple pairs of surface patches placed on the patient's skin. For example, the first pair of surface patch electrodes may include a front surface patch electrode and a back surface patch electrode, and the second pair may include a right surface patch electrode and a left surface patch electrode, typically positioned on opposite sides of the body and forming axes orthogonal to each other. The localization and navigation system 130 applies a voltage signal between each pair of surface patch electrodes to generate an electrical potential field (also called an impedance field) throughout the patient's body, and the impedance-based localization signal 418 measured by each sense channel is used to locate the corresponding electrode or multiple electrodes in the three-dimensional space of the patient's body. The impedance-based localization signal 418, measured by the second sense channel 400b and corresponding to multiple electrodes 304a1, 304a2, 304a4, generally corresponds to a point in the space between the multiple electrodes (e.g., a "virtual" electrode located at the centroid of the physical electrodes 304a1, 304a2, 304a4). The impedance-based localization signal 418 associated with a sense channel connected to a single electrode, as well as the impedance-based localization signal 418 associated with a sense channel connected to multiple electrodes, may be used in operations related to shape detection (described with respect to Figures 6 to 9) and pinjack detection (described with respect to Figure 10), in addition to typical localization and navigation purposes.

[0053] The electrocardiogram (EGM) signal 416 is an electrical cardiac signal measured from within the ventricle. The EGM signal 416 may be measured with respect to a single channel (e.g., a unipolar signal measured by either a first channel connected to a single electrode 304a3 or a second channel connected to multiple electrodes 304a1, 304a2, and 304a4) or a pair of channels (e.g., a bipolar signal measured between two channels, such as between the first channel and the second channel). In some applications, it is beneficial for the bipolar EGM signal to be based on signals measured with respect to electrodes located on the same spline. For example, the first EGM signal 416 may be based on the signal from a first channel connected to electrode 304a3 located on the first spline 302a and the signals from second channels connected to electrodes 304a1, 304a2, and 304a4, also located on the first spline 302a. In some applications, the EGM pair relies on the connection of a pin jack associated with cable 111 (shown in Figure 1) to an input socket 110. A method for verifying that the pin jack of cable 111 is connected to the appropriate input socket 110 in order to provide the desired EGM signal is described with respect to Figure 10 and utilizes both an electrode impedance signal 414 and an impedance-based localization signal 418.

[0054] Figure 4 is a flowchart 420 illustrating the steps performed by the tissue contact module 122 (shown in Figure 1) to evaluate spline tissue contact / proximity based on signals received from at least one sense channel (e.g., the second sense channel 400b shown in Figure 3) connected to multiple electrodes. It should be noted that in some applications, the term “contact state” is a binary determination of whether the electrode is “in contact” or “not in contact” with the tissue. In other embodiments, the term “contact state” may include additional contact states such as “intermittent contact.” In yet another embodiment, the term “contact state” may represent the proximity of the electrode to adjacent tissue. The term tissue contact / proximity is used throughout, but may include any of these definitions.

[0055] Electrode impedance-based tissue contact / proximity measured for a single electrode is generally well understood. However, the evaluation changes for sense channels connected to multiple electrodes. Generally, the sensitivity of the measured electrode impedance signal connected to multiple electrodes is significantly lower than that of the electrode impedance signal associated with a single electrode. While scaling the measured electrode impedance signal or redefining the threshold used may be utilized to evaluate tissue contact / proximity, this does not adequately address the challenge that the impedance measured by a sense channel connected to multiple electrodes is always measured as a combined value, and therefore the derived metric is relevant not only to a single electrode but to all connected electrodes. The embodiment shown in Figure 4 addresses this problem by generating a value related to spline tissue contact / proximity rather than individual electrode tissue contact / proximity.

[0056] In step 422, a first electrode impedance signal is measured from the first electrode 304a3 connected to the first channel 400a. In the case of the basket assembly shown in Figures 2A and 2B, this may also include measuring the electrode impedance signal for each of the multiple channels connected to a single electrode (e.g., electrodes 304a3, 304b3, 304c3, 304d3, and 304e3).

[0057] In step 424, a second electrode impedance signal is measured from multiple electrodes (e.g., electrodes 304a1, 304a2, 304a4) connected to the second channel 400b. For the basket assembly shown in Figures 2A and 2B, this may also include measuring the electrode impedance signal for each of the multiple channels connected to multiple electrodes (e.g., electrodes 304a1, 304a2, 304a4, electrodes 304b1, 304b2, 304b4, electrodes 304c1, 304c2, 304c4, electrodes 304d1, 304d2, 304d4, electrodes 304e1, 304e2, 304e4).

[0058] In step 426, tissue contact / proximity is evaluated based on the measured first and second electrode impedance signals. The second electrode impedance signal, measured by a channel connected to multiple electrodes, is lower than the measured electrode impedance signal because multiple electrodes are connected in parallel. This difference in the measured electrode impedance signals can be explained in several ways. In one embodiment, as described in more detail in Figure 5A, the first and second electrode impedance signals are combined, and the combined value is compared to a baseline value or threshold for evaluating tissue / contact proximity. In another embodiment, used alone or in conjunction with the first method, the first electrode impedance signal is compared to a first baseline / threshold to determine a first change in impedance, and the second electrode impedance signal is compared to a second baseline / threshold to evaluate a second change in impedance. The first and second changes in impedance are then combined and used to evaluate tissue / contact proximity. The term baseline value may be defined as the expected or previously measured electrode impedance signal when the electrode is not in contact with adjacent tissue (i.e., the lowest expected impedance value). The baseline value may be empirically assigned based on the observed electrode impedance signal measured when the electrode is not in contact with adjacent tissue, or it may be calculated based on the expected value.

[0059] With respect to the basket assemblies shown in Figures 2A and 2B, tissue contact / proximity evaluations are performed for each spline. That is, if a first electrode impedance signal is generated for electrode 304a3 from the first spline 302a, a second electrode impedance signal is generated for electrodes 304a1, 304a2, and 304a4 associated with the first spline 302a. Separate evaluations of the other splines 302b, 302c, 302d, and 302e may be performed based on the first and second electrode impedance signals measured for the electrodes associated with each spline.

[0060] Figures 5A and 5B are flowcharts illustrating the steps performed by the tissue contact module to evaluate tissue contact / proximity based on local electrode impedance signals received from at least one sense channel connected to multiple electrodes (e.g., the second sense channel 400b shown in Figure 3). The method described in Figure 5A describes how the impedance signals from each sense channel are combined before being compared to a threshold to determine tissue contact / proximity, while the method described in Figure 5B describes how the impedance signals from each channel are compared to separate thresholds and then combined.

[0061] In the embodiment shown in Figure 5A, a first electrode impedance signal and a second electrode impedance signal are measured in steps 502 and 504. The first electrode impedance signal is measured by a first channel connected to a first electrode (e.g., electrode 304a3), and the second electrode impedance signal is measured by a second channel connected to a plurality of electrodes (e.g., electrodes 304a1, 304a2, 304a4).

[0062] In step 506, the first electrode impedance signal and the second electrode impedance signal are combined to form a sum impedance signal. For example, in one embodiment, the first electrode impedance signal and the second electrode impedance signal are combined according to the following equation: TIFF2026122921000002.tif12170 Here, Imp spline is the impedance of the spline, Imp1 is the first impedance signal measured for each individual electrode connected to the first channel, Imp2 is the second impedance signal measured for multiple electrodes connected to the second channel, n is the number of electrodes connected to the second channel (e.g., 3 in the example shown in Figure 3), and s is the total number of channels (e.g., 2 in the example described here). In this way, the value Imp splineThis provides a composite impedance value that can be used to evaluate tissue contact across the entire spline, rather than at specific electrodes located on the spline. In other examples, the first electrode impedance signal and the second electrode impedance signal may be combined according to other equations.

[0063] In step 508, spline tissue contact / proximity is evaluated based on a comparison of the aggregated impedance signal with a baseline value or threshold. As mentioned above, the measured electrode impedance signal increases as the electrode approaches / contacts adjacent tissue, although the sensitivity of channels connected to multiple electrodes is low. Generally, a certain level of tissue proximity / contact is detected when the aggregated impedance signal is greater than the threshold (or a predetermined amount greater than the baseline). However, rather than generating an output associated with a specific electrode regarding tissue contact / proximity, the tissue contact / proximity evaluation is performed at the spline level, where the spline includes an electrode connected to the first channel and multiple electrodes connected to the second channel.

[0064] The threshold used to detect spline tissue contact / proximity may vary depending on the application. For example, in one application, pulsed-field ablation (PFA) treatment may be initiated in response to all electrodes on the spline being in full contact with the tissue. In this example, the aggregate impedance signal is compared to a threshold that is significantly greater than the baseline value (e.g., 30% greater than the baseline value). In other applications, the threshold may be met if at least one electrode is in full contact with the adjacent tissue, or if multiple electrodes are in partial contact (i.e., proximity) with the adjacent tissue. In this example, the aggregate impedance signal may be compared to a lower threshold (e.g., 16% greater than the baseline value). In yet another application, it may be desirable to set a threshold that can be reached when only one of multiple electrodes associated with the second channel is in contact with the tissue, or when multiple electrodes are in partial contact with the adjacent tissue. In this application, an even lower threshold may be set (e.g., 4.5% greater than the baseline value). In other applications, various other thresholds may be selected depending on the application.

[0065] In step 510, an output is generated that displays the evaluated tissue contact / proximity for each of the multiple splines. With respect to the electrode assembly 109 shown in Figures 2A and 2B, a tissue contact / proximity output is generated and displayed for each of the multiple splines (e.g., each of the five splines 302a to 302e). The display may include only the tissue contact / proximity output (e.g., in contact, partially in contact, not in contact), or it may also include information on the combined impedance measurement and / or the first and second impedances measured by each channel.

[0066] In the embodiment shown in Figure 5B, a first electrode impedance signal and a second electrode impedance signal are measured in steps 514 and 516. The first electrode impedance signal is measured by a first channel connected to a first electrode (e.g., electrode 304a3), and the second electrode impedance signal is measured by a second channel connected to a plurality of electrodes (e.g., electrodes 304a1, 304a2, 304a4).

[0067] In step 518, the first electrode impedance signal is compared to a first baseline value to detect a first change in impedance from the baseline. For example, in some embodiments, if the baseline impedance of the electrode is 300 ohms (Ω) and the measured first electrode impedance signal is 350 Ω, then the change in value or delta is 50 Ω.

[0068] In step 520, the second electrode impedance signal is compared to the second baseline value to detect a second change in impedance from the second baseline. The first and second baseline values ​​may be different.

[0069] In step 522, the second change in impedance is scaled so that it can be compared to the first change in impedance. In one embodiment, the change in impedance is scaled by multiplying it by the number of electrodes connected to the sense channel (for example, three in the example shown in Figure 3).

[0070] In step 524, the first change in impedance and the second change in scaled impedance are combined to obtain a composite change in impedance (for example, the first change in impedance is added to the second change in scaled impedance). In other embodiments, instead of combining the first change in impedance and the second change in scaled impedance, each change in impedance is compared to a threshold to evaluate tissue contact / proximity for each channel. For a sense channel connected to a single electrode, this is straightforward, but for a sense channel connected to multiple electrodes, the tissue contact / proximity evaluation based on comparison is with respect to multiple electrodes rather than a specific electrode. Therefore, in some embodiments, it is beneficial to combine the first change in impedance and the second change in scaled impedance to obtain a composite change in impedance, and to use that value to evaluate the tissue contact / proximity of the spline as a whole.

[0071] In step 526, tissue contact / proximity is evaluated based on a comparison of the combined impedance change value with a threshold. This is a comparison of the impedance signal with a baseline value or threshold. As mentioned above, the measured electrode impedance signal increases as the electrode approaches / contacts adjacent tissue, although the sensitivity of channels connected to multiple electrodes is low. Generally, a certain level of tissue proximity / contact is detected when the combined impedance signal is greater than the threshold (or a predetermined amount greater than the baseline). As mentioned earlier, various thresholds may be selected depending on the type of tissue contact / proximity to be detected.

[0072] In step 528, an output is generated that displays the evaluated tissue contact / proximity of each of the multiple splines. With respect to the electrode assembly 109 shown in Figures 2A and 2B, a tissue contact / proximity output is generated and displayed for each of the multiple splines (e.g., each of the five splines 302a to 302e). The display may include only the tissue contact / proximity output (e.g., in contact, partially in contact, not in contact), or it may also include information on the combined impedance change value and / or the first and second impedances measured by each channel.

[0073] Figure 6 is a flowchart 600 illustrating the steps performed by a shape detection module to detect the shape of the distal end of a medical device based on impedance-based localization signals received from multiple first channels and multiple second channels.

[0074] In step 602, the position of the first electrode is determined based on a first impedance-based localization signal received from the first channel. In the example shown in Figures 2A to 2B, the position of the first electrode is determined for each of the multiple splines (i.e., the impedance-based localization is measured for each of electrodes 304a3 to 304e3). As described above with respect to Figure 3, the impedance-based localization signal 418 is one of the types of signals that can be measured by each sense channel.

[0075] In step 604, the combined position of the multiple electrodes connected to the second sense channel is determined based on a second impedance-based localization signal received from the second channel. In the example shown in Figure 3, the combined position is based on an impedance-based localization signal 418 generated by the second sense channel 400b and represents a “virtual” electrode located roughly in the center of the physical electrodes 304a1, 304a2, and 304a4. In the embodiment shown in Figures 2A-2B, the combined position will be generated for the multiple electrodes associated with each of the multiple splines (e.g., a first combined position generated for electrodes 304a1, 304a2, and 304a4 located on the first spline 302a, a second combined position generated for electrodes 304b1, 304b2, and 304b4 located on the second spline 302b, etc.).

[0076] In step 606, the deployment state of the electrode assembly 109 is determined based on the position of the first electrode and the combined position of the multiple electrodes connected to the sense channel. The determination is based on the relative position of the first electrode to the combined position of the multiple electrodes. The method described with respect to Figure 7 illustrates one method for determining the deployment state based on the individual positions of the first electrode and the combined position of the multiple electrodes, but other methods may be used to efficiently determine the deployment state.

[0077] In step 608, an output is generated indicating the deployment state of the electrode assembly 109. In some embodiments, this may include indicating the deployment state as "low profile," "basket," or "flower." In other embodiments, the output may graphically represent the electrode assembly 109 in the determined deployment state.

[0078] Figure 7 is a flowchart 700 illustrating in further detail the steps performed by the shape detection module to detect the shape of the distal end of a medical device based on impedance-based localization signals received from multiple first channels and multiple second channels.

[0079] In step 702, the position of the first electrode is determined based on a first impedance-based localization signal received from the first channel. In the embodiments shown in Figures 8A to 8B, the positions of the first electrode relative to each spline are indicated by points 804a to 804e.

[0080] In step 704, the combined position of the multiple electrodes connected to the second sense channel is determined based on a second impedance-based localization signal received from the second channel. In the embodiments shown in Figures 8A to 8B, the combined position is indicated by points 806a to 806e.

[0081] In step 706, for each spline, a vector is calculated between the position of the first electrode and the combined position of the multiple electrodes. In the embodiments shown in Figures 8A to 8B, the calculated vectors are indicated by arrows 808a to 808e, as shown in the comparison between the calculated vectors when the electrode assembly 109 is deployed in a basket configuration (Figure 8A) and a flower configuration (Figure 8B). In the flower configuration, the calculated vectors 808a to 808e are more orthogonal to the longitudinal axis 810 of the shaft 106 and point outward in all different directions. In the basket configuration, the calculated vectors 808a-808e are less orthogonal to the longitudinal axis 810 of the shaft 106 and still point outward, but have a longitudinal component pointing in the same direction. Although not shown, when the electrode assembly 109 is deployed in a low-profile configuration, the calculated vectors 806a to 806e point in the same direction and are approximately parallel to the longitudinal axis 810 of the shaft 106. In some embodiments, the lengths of vectors 808a to 808e are normalized so that each vector has the same length (e.g., the length of "1").

[0082] In steps 708-712, the calculated vectors 808a-808e are used to determine the deployment state. There are several ways to utilize these vectors 808a through 808e, but the steps illustrated in steps 708 through 712 are just one example. In step 708, the multiple vectors 808a through 808e (or normalized vectors) are summed to produce a sum vector denoted as "S". In some embodiments, the sum vector S may also be normalized to produce a normalized sum vector "NS".

[0083] In step 710, a unit vector is defined to provide a vector comparable to the sum vector or normalized sum vector. The unit vector can be defined in several ways. In one embodiment, the unit vector is the unit normal vector of a plane defined to best fit the multiple positions 804a to 804e and 806a to 806e found in steps 702 and 704 (however, in some embodiments, the unit normal vector may also be defined with respect to a plane that best fits only the electrode positions 804a to 804e or only the composite electrode positions 806a to 806e). The unit normal vector is defined as perpendicular (or normal) to the defined best-fitting plane. In other embodiments, the vector compared to the sum vector or normalized sum vector is based on the orientation of the shaft 106 (for example, a vector defined along the longitudinal axis 810 of the shaft 106 based on a magnetic sensor located within the shaft 106).

[0084] In step 712, the sum vector (or normalized sum vector) is compared to the unit vector defined in step 710. In some embodiments, the comparison is performed by performing a dot product between the sum vector and the unit vector defined in step 710. The results of the dot product calculation for various configurations of the electrode assembly 109 (e.g., low profile, basket profile, and flower profile) are shown in the graphs in Figure 9. As illustrated, for the low profile configuration (depending on how the vector is defined) where the sum vector points in the same direction as the unit normal vector defined in step 710, the dot product provides a value close to "1". For the basket profile configuration where the sum vector points somewhat in the same direction as the unit normal vector defined in step 710, the dot product provides a value equal to approximately "0.5", and for the flower profile configuration where the sum vector is perpendicular to the unit normal vector defined in step 710 or at an angle greater than 90°, the dot product is close to "0" or slightly negative.

[0085] In step 714, output is generated that describes the deployment state of the electrode assembly. As described above, this may include indicating the deployment state as "low profile," "basket," or "flower." In other embodiments, the output may diagram the electrode assembly 109 in the determined deployment state.

[0086] Figure 10 is a flowchart 1000 illustrating the steps performed by the pin jack detection module 126 (shown in Figure 1), ensuring that the pin jacks associated with the cable 111 are connected to the appropriate input sockets 110 (as shown in Figure 1) to generate the desired bipolar potential diagram (EGM) pair. This method generally involves receiving input from each of the pin jacks connected to the input sockets (i.e., each sense channel) without knowing which electrode is associated with each sense channel. This is determined / verified by the steps shown in Figure 10 so that at the end of the process, the sense channels associated with the selected electrodes (e.g., sense channels associated with electrodes on the same spline) are determined and available for subsequent operation as a bipolar pair (e.g., to form a bipolar EGM signal based on signals received from the two sense channels). In some embodiments, after determining the desired pin jack / input socket configuration, instructions can be provided to physically move the pin jacks to the selected input sockets. In other embodiments, after determining the desired pin jack / input socket configuration, the desired pair of pin jacks / input sockets can be selected in software. This embodiment applies to the example shown in Figures 2A, 2B, and 3, where each spline (e.g., spline 302a) includes one electrode (e.g., electrode 304a3) connected to a first sense channel and three electrodes (e.g., electrodes 304a1, 304a2, and 304a4) connected to a second sense channel. In this example, it is desirable that these sense channels associated with electrodes on a single spline be organized or paired together to measure bipolar EGM signals between their respective channels, rather than creating bipolar pairs between electrodes located on different splines. In other embodiments, other pairings may be desired, and the algorithm may be modified accordingly.

[0087] In some embodiments, a decision is made before initiating the verification process in step 1002. For example, depending on the electrode array 109 being used, some configurations are not suitable for accurate measurements in some deployment configurations. For example, in the basket configuration shown in Figures 2A and 2B, when the electrode array 109 is deployed in a basket configuration (Figure 2A) or a flower configuration (Figure 2B), the signals received from the electrodes are typically isolated from each other and may be used to verify pinjack verification. However, if the electrode array 109 is in a low-profile configuration (not shown), some of the electrodes may be in contact with each other, potentially distorting the measurements. In this example, the verification process will only be initiated in response to the electrode array 109 transitioning from a low-profile configuration to either a basket configuration or a flower configuration. In some embodiments, an output is generated indicating that the verification process cannot be initiated and therefore the pinjack configuration cannot be verified.

[0088] Assuming the verification process has started, in step 1002, the electrode impedance signal is measured for each of the multiple sense channels, including at least some sense channels connected to a single electrode and other sense channels connected to multiple electrodes. For example, in the embodiments shown in Figures 2A, 2B, and 3, five sense channels are connected to a single electrode (e.g., electrodes 304a3 to 304e3), and five sense channels are connected to multiple electrodes. For example, one sense channel is connected to electrodes 304a1, 304a2, and 304a4, and a second sense channel is connected to electrodes 304b1, 304b2, and 304b4.

[0089] In step 1004, the position is determined based on the impedance-based localization signal received in each channel. At this point, it has not yet been verified which of the multiple sense channels are connected to a single electrode and which of the multiple sense channels are connected to multiple electrodes. Therefore, at least some of the determined positions correspond to individual electrodes, and at least some of the determined positions correspond to composite positions (i.e., "virtual" electrodes) associated with multiple electrodes connected to a single sense channel.

[0090] In step 1006, the sense channels are organized based on the electrode impedance signals measured in step 1002. In one example, the sense channels are ordered from the highest measured electrode impedance to the lowest measured electrode impedance. It is assumed that a sense channel connected to one electrode will show a higher electrode impedance measurement. Based on knowledge of the total number of channels connected to a single electrode (e.g., five in the examples shown in Figures 2A, 2B, and 3), the five highest electrode impedance measurements are assumed to be associated with sense channels connected to a single electrode and are organized into a first group. The remaining sense channels (i.e., the lowest electrode impedance measurements) are organized into a second group.

[0091] In step 1008, the impedance signals are reviewed to determine whether they are valid for use in pin jack verification. In some embodiments, it would be beneficial to verify that each electrode is located in the blood pool at the time of measurement and that the corresponding electrode impedance measurements vary based on the number of electrodes connected to each channel, rather than contact with adjacent tissue. While this can be assessed in various ways, electrode impedance data should generally be neatly grouped into high-impedance measurements associated with sense channels connected to a single electrode and low-impedance measurements associated with sense channels connected to multiple electrodes. If the collected electrode impedance measurements cannot be neatly organized into two groups, this indicates that one or more electrodes may be in contact with adjacent tissue or short-circuited with adjacent electrodes, making it difficult to distinguish which sense channels are connected to a single electrode and which are connected to multiple electrodes.

[0092] In one embodiment, sense channels are classified into two groups based on electrode impedance, and then the impedance range associated with each group is calculated. That is, the first impedance range is calculated as the difference between the highest and lowest impedances of the first group, and the second impedance range is calculated as the difference between the highest and lowest impedances of the second group. Furthermore, a spread between the two groups is calculated (i.e., the minimum impedance value associated with the first group is subtracted from the maximum impedance value associated with the second group). In some embodiments, the spread is compared to the maximum values ​​of the two ranges to determine whether the electrode impedance data is valid for pin jack verification (in some embodiments, the spread is compared to a parameterized value generated based on the maximum values ​​of the two ranges). Generally, if the spread is smaller than the parameterized value of the maximum values ​​of the two ranges, this indicates that the electrode impedance measurements are not organized into two different groups and that the electrode impedance measurements should be used to verify the pin jack configuration.

[0093] If, in step 1008, it is determined that the impedance signal is not available for verifying the pin jack, then in step 1009, an output is generated for the user indicating that the pin jack configuration cannot be verified at this time. The verification process can then be restarted using new electrode impedance and position measurements. If, in step 1008, it is determined that the impedance signal is available for verifying the pin jack, the process continues in step 1010.

[0094] In step 1010, the position signals are reviewed to determine whether they can be used for pin jack verification. Generally, it is assumed that the impedance-based positions of individual electrodes connected to the first sense channel are located on the same spline and are closest to the combined impedance-based position of multiple electrodes associated with the second sense channel. However, bending or other physical deformation of the electrode array within the patient's body may cause this assumption to be false. In step 1010, the determined position / combined position is used to determine whether deformation of the electrode array may make it difficult to use the position / combined position of each channel to pair the channels associated with electrodes on the same spline with each other to create the desired bipolar EGM. As in step 1008, many methods can be used to make this determination.

[0095] In one example, a first position calculated for a first sense channel is selected, and the distance between this position and the positions / combined positions calculated for the other sense channels is calculated (for example, nine distances are calculated in the provided example). The smallest distance (referred to herein as "D1") and the second smallest distance (referred to herein as "D2") are selected and compared to each other. In the best-case scenario, the minimum distance D1 represents the distance between an individual electrode located on the first spline (e.g., electrode 304a3) and the combined position of electrodes 304a1, 304a2, and 304a4 located on the same spline. Similarly, in the best-case scenario, the second smallest distance D2 represents the distance between an individual electrode on the first spline and the position or combined position of an electrode on a different spline (and therefore much farther away). In other words, the smallest distance D1 must be significantly smaller than the second smallest distance D2. This can be tested in many ways using thresholds or parameterized values. For example, the minimum distance D1 may be parameterized by multiplying it by a selected value and comparing the parameterized value to a second minimum distance D2. If the second minimum distance D2 is smaller than the parameterized value, this indicates that the electrode positions / combined positions are not reliable in determining whether the electrodes are located on the same spline. In this example, if distance is not available to determine whether the sense channels are connected to electrodes on the same spline, step 1009 produces an output indicating that the pinjack configuration cannot be verified at this time. If the second minimum distance D2 is not smaller than the parameterized value, this indicates that the positions of the electrodes connected to each sense channel can be used to verify the sense channels connected to electrodes on the same spline. The same operation will be repeated for each sense channel. If, in step 1010, it is determined that the positions / combined positions associated with each sense channel are located relative to each other in order to identify electrodes on the same spline, the process proceeds to step 1012.

[0096] In step 1012, each sense channel in the first group is paired with the sense channel from the second group that is closest to the electrode associated with the sense channel in the first group, based on the determined position / combined position of the electrode associated with each sense channel. For example, suppose the sense channel selected from the first group corresponds to electrode 304a3. The impedance-based position of electrode 304a3 (known from step 1004) is compared with the combined position associated with each of the sense channels in the second group (corresponding to each of the sense channels connected to multiple electrodes). The combined position from the second group that is closest to the position of electrode 304a3 can be determined to be associated with the sense channels connected to electrodes 304a1, 304a2, and 304a4. In this way, a pair is made between the sense channel selected from the first group and the sense channel selected from the second group. The selected sense channel pair should correspond to electrodes located on the same spline and can therefore be used to measure a bipolar EGM pair based on the EGM signals measured by each channel. This process is repeated until each sense channel in the first group is paired with a sense channel in the second group. In this example, it is assumed that the number of sense channels associated with a single electrode is equal to the number of sense channels associated with multiple electrodes. The resulting pairs can be used, either physically or in software, to create the desired pairings between the pin jacks and input sockets, or to verify that the connections are correct.

[0097] In step 1010, an output is generated that identifies the electrodes connected to each socket, and it is verified that the desired pairing of sense channels is correctly connected to generate the desired bipolar EGM pair.

[0098] While the present invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various modifications may be made without departing from the scope of the invention, and that equivalents may be substituted for the elements. Furthermore, many modifications may be made without departing from the essential scope of the invention to adapt the teachings of the invention to specific situations or materials. Accordingly, the present invention is not limited to the specific embodiments disclosed, but is intended to include all embodiments that fall within the scope of the appended claims.

[0099] Clause 1. A computer-implemented method for evaluating tissue contact of a plurality of electrodes located in a medical device, comprising: measuring a first electrode impedance signal associated with a first electrode using a first sense channel; measuring a second electrode impedance signal associated with at least a second electrode and a third electrode using a second sense channel, wherein the second electrode and the third electrode are electrically connected to each other but not to the first electrode; and evaluating tissue contact / proximity based on the first electrode impedance signal and the second electrode impedance signal.

[0100] Clause 2. The computer-aided method according to Clause 1, further comprising: evaluating the tissue contact / proximity by combining the first electrode impedance signal and the second electrode impedance signal to obtain a combined electrode impedance signal; and determining the tissue contact / proximity by comparing the combined electrode impedance signal with a baseline value.

[0101] Clause 3. The computer implementation method according to Clause 2, wherein comparing the combined electrode impedance signal to a baseline value includes comparing the combined electrode impedance signal to a threshold, wherein tissue contact is detected if the combined electrode impedance signal is greater than the threshold.

[0102] Clause 4. The computer implementation method according to Clause 3, wherein the threshold is selected to represent that both the first electrode and at least one of the second electrode and the third electrode are in contact with tissue.

[0103] Clause 5. The computer-aided method according to Clause 3, wherein the threshold is selected to indicate that the first electrode or at least one of the second electrode and the third electrode is in contact with tissue.

[0104] Clause 6. A computer implementation method according to any one of Clauses 2 to 5, wherein combining the first electrode impedance signal and the second electrode impedance signal to form an aggregate electrode impedance signal includes scaling the second electrode impedance signal to a value representing a single electrode impedance signal.

[0105] Clause 7. The computer implementation method according to Clause 6, wherein scaling the second electrode impedance signal comprises multiplying the second electrode impedance signal by the number of electrodes connected to the second sense channel.

[0106] Clause 8. The computer implementation method according to Clause 7, further comprising adding the first electrode impedance signal and the second electrode impedance signal to the scaled second electrode impedance signal and dividing by the number of sense channels.

[0107] A computer implementation method according to any one of Clauses 1 to 8, wherein evaluating tissue contact / proximity further includes comparing the first electrode impedance signal to a first baseline value in order to detect a first change in impedance; comparing the second electrode impedance signal to a second baseline value in order to detect a second change in impedance; scaling the second change in impedance to a value representing a single electrode impedance measurement; combining the first change in impedance and the scaled second change in impedance; and evaluating tissue contact / proximity based on a comparison of the combined change in impedance and a threshold.

[0108] Clause 10. The computer implementation method according to Clause 9, wherein scaling the second change in impedance comprises multiplying the second change in impedance by the number of electrodes connected to the second sense channel.

[0109] Clause 11. The computer mounting method according to any one of Clauses 1 to 10, wherein the first electrode, the second electrode, and the third electrode are located on a single spline.

[0110] Clause 12. The computer implementation method according to Clause 11, further comprising generating an output indicating tissue contact / proximity of the spline based on the measured first electrode impedance signal and the measured second electrode impedance signal.

[0111] Clause 13. A computer implementation method for determining the deployment state of an electrode assembly located at the distal end of a catheter having a plurality of splines and a plurality of electrodes on each spline, comprising: calculating the position of a first electrode located on each spline based on a first impedance-based positioning signal received by a first sense channel with respect to each spline; calculating the combined position of at least a second electrode and a third electrode located on each spline based on a second impedance-based positioning signal received by a second sense channel with respect to each spline; and determining the deployment state of the electrode assembly based on the position of the first electrode and the combined position of at least the second electrode and the third electrode.

[0112] Clause 14. The computer mounting method described in Clause 13, wherein the deployment state of the electrode assembly includes a low-profile state, a basket-profile state, and a flower-profile state.

[0113] Clause 15. The computer implementation method according to Clause 13 or 14, wherein determining the deployment state of the electrode assembly further includes, for each spline, calculating a vector between the position of the first electrode and the combined position of at least the second electrode and the third electrode, and determining the deployment state based on the vector calculated for each of the plurality of splines.

[0114] Clause 16. The computer implementation method according to Clause 15, further comprising: summing the vectors calculated for each of the plurality of splines to generate a total vector; comparing the total vector with a unit vector; and determining the deployment state of the electrode assembly based on the comparison between the total vector and the unit vector.

[0115] Clause 17. The computer implementation method according to Clause 16, wherein the unit vector is the unit normal vector of a plane defined to best fit the position of the first electrode associated with each spline, a plane defined to best fit the combined position of the second and third electrodes associated with each spline, or a plane defined to best fit both the position of the first electrode associated with each spline and the combined position of the second and third electrodes.

[0116] Clause 18. The computer implementation method according to Clause 17, wherein the sum vector is compared with the unit vector using a dot product function, and the dot product output is used to determine the deployment state of the distal end of the catheter.

[0117] A computer implementation method according to any one of Clauses 16 to 18, further comprising: calculating a second vector between the positions of the first electrodes on adjacent splines; and determining a deployment state based on the first vector calculated for each of the plurality of splines and the second vector between the positions of the first electrodes on adjacent splines.

[0118] Clause 20. A computer implementation method for determining an appropriate pin jack connection sequence for connecting to a plurality of electrodes located at the distal end of a medical device, comprising: measuring an electrode impedance signal associated with each of a plurality of sense channels; determining a position / combined position associated with each of the plurality of sense channels based on an impedance-based localization signal measured by each sense channel, wherein the position / combined position corresponds to an electrode or group of electrodes connected to each of the plurality of sense channels; organizing the plurality of sense channels into a first group of sense channels and a second group of sense channels based on the measured electrode impedance signals; pairing each sense channel in the first group with the nearest sense channel in the second group based on the determined position / combined position of each of the plurality of sense channels; and measuring an electrodynamic diagram (EGM) signal based on the pairing of each sense channel in the first group with the sense channels in the second group.

[0119] Clause 21. The computer implementation method according to Clause 20, wherein at least some of the sense channels are connected to a single electrode located on the electrode assembly located at the distal end of the medical device, and at least some of the sense channels are connected to a plurality of electrodes located on the electrode assembly located at the distal end of the medical device.

[0120] Clause 22. The computer implementation method according to Clause 21, wherein the measured electrode impedance signal associated with a sense channel connected to a single electrode is greater than the measured electrode impedance signal associated with a sense channel connected to multiple electrodes.

[0121] Clause 23. The computer implementation method according to any one of Clauses 20 to 22, wherein the electrode assembly located at the distal end of the medical device comprises a plurality of splines, each spline having a plurality of electrodes, and at least some of the sense channels are connected to a single electrode on each spline, and at least some of the channels are connected to a plurality of electrodes on the same spline.

[0122] Clause 24. A computer program product that, when executed by a computer, includes instructions causing the computer to perform any of the methods described in Clauses 1 through 23.

Claims

1. A computer implementation method for evaluating tissue contact of multiple electrodes located in a medical device, Using the first sense channel, measure the first electrode impedance signal associated with the first electrode, Measuring a second electrode impedance signal associated with at least a second electrode and a third electrode using a second sense channel, wherein the second electrode and the third electrode are electrically connected to each other but not to the first electrode, and measuring the second electrode impedance signal. A method comprising evaluating tissue contact / proximity based on the first electrode impedance signal and the second electrode impedance signal.

2. Evaluating the aforementioned tissue contact / proximity further, The first electrode impedance signal and the second electrode impedance signal are combined to form a combined electrode impedance signal. The computer implementation method according to claim 1, further comprising comparing the combined electrode impedance signal with a baseline value to determine tissue contact / proximity.

3. The computer implementation method according to claim 2, wherein comparing the combined electrode impedance signal with a baseline value includes comparing the combined electrode impedance signal with a threshold, and tissue contact is detected when the combined electrode impedance signal is greater than the threshold.

4. The computer implementation method according to claim 3, wherein the threshold is selected to indicate that both the first electrode and at least one of the second electrode and the third electrode are in contact with tissue.

5. The computer implementation method according to claim 3, wherein the threshold is selected to indicate that the first electrode or at least one of the second electrode and the third electrode is in contact with tissue.

6. The computer implementation method according to claim 2, wherein combining the first electrode impedance signal and the second electrode impedance signal to obtain an aggregate electrode impedance signal includes scaling the second electrode impedance signal to a value representing a single electrode impedance signal.

7. The computer implementation method according to claim 6, wherein scaling the second electrode impedance signal comprises multiplying the second electrode impedance signal by the number of electrodes connected to the second sense channel.

8. The computer implementation method according to claim 7, wherein combining the first electrode impedance signal and the second electrode impedance signal further comprises adding the first electrode impedance signal to the scaled second electrode impedance signal and dividing by the number of sense channels.

9. Evaluating tissue contact / proximity is further, To detect a first change in impedance, the first electrode impedance signal is compared with a first baseline value, To detect a second change in impedance, the second electrode impedance signal is compared with a second baseline value, The second change in impedance is scaled to a value representing a single-electrode impedance measurement, Combining the first change in impedance with the second change in scaled impedance, A computer implementation method according to claim 1, comprising evaluating tissue contact / proximity based on a comparison of a combined change in impedance with a threshold.

10. The computer implementation method according to claim 9, wherein scaling the second change in impedance comprises multiplying the second change in impedance by the number of electrodes connected to the second sense channel.

11. The computer mounting method according to claim 1, wherein the first electrode, the second electrode, and the third electrode are located on a single spline.

12. The computer implementation method according to claim 11, further comprising generating an output indicating tissue contact / proximity of the spline based on the measured first electrode impedance signal and the measured second electrode impedance signal.

13. A computer implementation method for determining the deployment state of an electrode assembly located at the distal end of a catheter having multiple splines and multiple electrodes on each spline, For each spline, the position of the first electrode located on each spline is calculated based on the first impedance-based localization signal received by the first sense channel. For each spline, the combined position of at least the second and third electrodes located on each spline is calculated based on the second impedance-based localization signal received by the second sense channel. A method comprising determining the deployment state of the electrode assembly based on the position of the first electrode and the combined position of at least the second electrode and the third electrode.

14. The computer mounting method according to claim 13, wherein the deployment state of the electrode assembly includes a low-profile state, a basket-profile state, and a flower-profile state.

15. Determining the deployment state of the electrode assembly further involves, For each spline, calculate the vector between the position of the first electrode and the combined position of at least the second electrode and the third electrode. The computer implementation method according to claim 13, further comprising determining the deployment state based on the vector calculated for each of the plurality of splines.

16. The vectors calculated for each of the aforementioned multiple splines are summed to generate a total vector, The sum vector is compared with the unit vector, The computer mounting method according to claim 15, further comprising determining the deployment state of the electrode assembly based on a comparison of the sum vector and the unit vector.

17. The computer implementation method according to claim 16, wherein the unit vector is the unit normal vector of a plane defined to best fit the position of the first electrode associated with each spline, a plane defined to best fit the combined position of the second and third electrodes associated with each spline, or a plane defined to best fit both the position of the first electrode associated with each spline and the combined position of the second and third electrodes.

18. The computer implementation method according to claim 17, wherein the sum vector is compared with the unit vector using a dot product function, and the dot product output is used to determine the deployment state of the distal end of the catheter.

19. Calculating a second vector between the positions of the first electrode on adjacent splines, The computer mounting method according to claim 16, further comprising determining the deployment state based on a first vector calculated for each of the plurality of splines and a second vector between the positions of the first electrodes on adjacent splines.

20. A computer implementation method for verifying the appropriate pin jack connection sequence for connecting to multiple electrodes located at the distal end of a medical device, Measuring the electrode impedance signal associated with each of the multiple sense channels, Determining a position / combined position associated with each of the plurality of sense channels based on impedance-based localization signals measured by each sense channel, wherein the position / combined position corresponds to an electrode or group of electrodes connected to each of the plurality of sense channels. Based on the measured electrode impedance signals, the plurality of sense channels are organized into a first sense channel group and a second sense channel group, Based on the determined position / combined position of each of the plurality of sense channels, each sense channel in the first group is paired with the nearest sense channel in the second group. A method comprising measuring a bipolar potential diagram (EGM) signal based on the pairing of each sense channel in the first group with the sense channels in the second group.

21. The computer implementation method according to claim 20, wherein at least some of the sense channels are connected to a single electrode located on an electrode assembly located at the distal end of the medical device, and at least some of the sense channels are connected to a plurality of electrodes located on the electrode assembly located at the distal end of the medical device.

22. The computer implementation method according to claim 21, wherein the measured electrode impedance signal associated with a sense channel connected to a single electrode is greater than the measured electrode impedance signal associated with a plurality of sense channels connected to multiple electrodes.

23. The computer implementation method according to claim 20, wherein the electrode assembly located at the distal end of the medical device is composed of a plurality of splines, each spline having a plurality of electrodes, at least some of the sense channels are connected to a single electrode on each spline, and at least some of the sense channels are connected to a plurality of electrodes on the same spline.

24. A computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform a method for determining the deployment state of an electrode assembly located at the distal end of a catheter having a plurality of splines and a plurality of electrodes on each spline, wherein the method is Using the first sense channel, measure the first electrode impedance signal associated with the first electrode, Measuring a second electrode impedance signal associated with at least a second electrode and a third electrode using a second sense channel, wherein the second electrode and the third electrode are electrically connected to each other but not to the first electrode, and measuring the second electrode impedance signal. A computer-readable medium, which includes evaluating tissue contact / proximity based on the first electrode impedance signal and the second electrode impedance signal.

25. A computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform a method for determining the appropriate pin jack connection sequence for connecting to a plurality of electrodes located at the distal end of a medical device, wherein the method is Based on a first impedance-based localization signal received by a first sense channel, the position of a first electrode located on each spline is calculated for each spline, Based on a second impedance-based localization signal received by a second sense channel, the combined position of at least a second electrode and a third electrode located on each spline is calculated for each spline, A computer-readable medium, comprising determining the deployment state of an electrode assembly based on the position of the first electrode and the combined position of at least the second electrode and the third electrode.

26. A computer-readable medium storing instructions that cause the processor to perform a method for evaluating tissue contact of a plurality of electrodes located on a medical device, wherein the method is: Measuring the electrode impedance signal associated with each of the multiple sense channels, Determining a position / combined position associated with each of the plurality of sense channels based on impedance-based localization signals measured by each sense channel, wherein the position / combined position corresponds to an electrode or group of electrodes connected to each of the plurality of sense channels. Based on the measured electrode impedance signals, the plurality of sense channels are organized into a first sense channel group and a second sense channel group, Based on the determined position / combined position of each of the plurality of sense channels, each sense channel in the first group is paired with the nearest sense channel in the second group. A computer-readable medium comprising measuring a bipolar potential diagram (EGM) signal based on the pairing of each sense channel in the first group with a sense channel in the second group.

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