Patent Description:
Medical conditions such as cardiac arrhythmia (e.g., atrial fibrillation (AF)) are often diagnosed and treated via intra-body procedures. For example, electrical pulmonary vein isolation (PVI) from the left atrial (LA) body is performed using ablation for treating AF. PVI, and many other minimally invasive catheterizations, cause damage to targeted organ tissue to prevent electrical activity through the organ tissue.

Intra-body organs include tissue that can vary within different portion of the intra-body organ and that can also vary within different areas of chambers of the intra-body organ, such as different chambers of the heart. Accordingly, tissue proximity, as determined based on electronic signals provided by one or more electrodes may be based on the specific tissue properties at a given location of an intra-body organ, such as at different areas of a heart.

<CIT> relates to a method of assessing the adequacy of contact between an ablation electrode and biological tissue within a biological organ having biological fluid therein that includes the steps of positioning the ablation electrode proximal the biological tissue; positioning a reference electrode a distance from the ablation electrode; measuring the impedance between the ablation electrode and the reference electrode at a first frequency and measuring the impedance between the ablation electrode and the reference electrode at a second frequency. The percentage difference between the first-frequency impedance and the second-frequency impedance provides an indication of the state of electrode/tissue contact. In general, a percentage difference of at least approximately <NUM>% serves as an indication of substantially complete electrode/tissue contact.

<CIT> relates to a system and method for measuring impedance across a plurality of electrodes and assessing proximity or contact between electrodes of a medical device and patient tissue. In one embodiment, contact is assessed between individual electrodes and cardiac tissue using bipolar electrode complex impedance measurements. Initially, baseline impedance values are established for each of the individual electrodes based on the responses of the electrodes to the applied drive signals. After establishing the baseline impedance values a series of subsequent impedance values are measured for each electrode.

Intra-body organs, such as a heart, are often mapped, examined, and/or operated on using catheter based medical procedures. During a catheter based medical procedure, a catheter with multiple electrodes may be inserted into the intra-body organ. The multiple electrodes of the catheter may be used to, for example, map the surfaces of the intra-body organ based on proximity sensing such that a surface at a given location may be mapped if a determination is made that one or more electrodes are proximate to or in contact with the surface. The number of electrodes on the catheter may determine the resolution of the data captured by a catheter. Additionally, the number of electrodes may determine the flexibility in performing electrode-based procedures such as an ablation procedure. A higher number of electrodes may result in a higher resolution such that, for example, a larger data set may be collected based on the higher number of electrodes or a finer ablation procedure may be performed based on a higher number of electrodes.

Utilization of a higher number electrodes from one or more electrodes may depend on the ability of a system to determine if the number of electrodes are proximate to (e.g., in contact with) tissue of an intra-body organ. For example, in order to determine if electrodes of a catheter are in contact with tissue of a heart chamber, a system may need to determine if the electrodes of the catheter are in contact with the tissue of the heart chamber. A proximity determination may be made by determining that the impedance sensed at the location of a tissue is above an impedance threshold for that specific location.

The impedance threshold in a first area (e.g., a first area of the heart) may be different than the impedance threshold at a second area (e.g., a second area of the heart). The impedance thresholds may vary between different areas of an intra-body organ based on properties of the tissue corresponding to the different areas of the intra-body organ. For example, properties such as tissue thickness, tissue density, tissue type, and the like may affect the impedance thresholds to determine whether an electrode or catheter is proximate (e.g., in contact) with the tissue. Accordingly, an electrode measured impedance value X (e.g., change in impedance or percentage change in impedance) at a first location may correspond to the electrode being proximate to a tissue surface at the first location (e.g., in contact with a tissue surface) whereas the same electrode measured impedance value X at a second location may not correspond to the electrode being proximate to a tissue surface at the second location.

Accordingly, a proximity determination may be based on knowledge of the location of a catheter as well as calculation of a property (e.g., impedance) of the intra-body organ as detected by the electrodes. However, location aware systems may be limited in the number of electrode signals that such a location aware system can analyze, thereby limiting the resolution that may be made available by a catheter or group of catheters that exceed the electrode count past the limit of the location aware system. The present invention enable a location agnostic system to determine proximity using a location agnostic system contact profile (i.e., a tissue contact profile for determining proximity to tissue) that is based on proximity determinations by a location aware system that is providing a subset of signals from a subset of the electrodes.

The exemplary embodiments disclosed herein may enable the use of a resource intensive location aware system that may be limited to a certain number of electrode inputs (e.g., <NUM> inputs as disclosed in examples herein) in combination with a high resolution location agnostic system that is capable of analyzing a greater number of inputs (e.g., <NUM> inputs as disclosed in examples herein). Accordingly, one advantage of implementing the exemplary embodiments disclosed herein may be to use a cost effective high resolution location agnostic system to obtain a higher resolution of data in combination with an existing lower resolution but location aware system to correlate the high resolution data with location based attributes (e.g., location based tissue impedance thresholds).

<FIG> is a diagram of an exemplary system <NUM> in which one or more exemplary features of the present invention can be implemented. System <NUM> may include components, such as a catheter <NUM>, that are configured to damage tissue areas of an intra-body organ. The catheter <NUM> may also be further configured to obtain biometric data. Although catheter <NUM> is shown to be a single point catheter with multiple electrodes 47A-N, it will be understood that a catheter of any shape that includes one or more elements (e.g., electrodes) may be used to implement the embodiments disclosed herein. System <NUM> includes a probe <NUM>, having shafts that may be navigated by a physician <NUM> into a body part, such as heart <NUM>, of a patient <NUM> lying on a bed <NUM>. According to exemplary embodiments, multiple probes may be provided, however, for purposes of conciseness, a single probe <NUM> is described herein but it will be understood that probe <NUM> may represent multiple probes. As shown in <FIG>, physician <NUM> may insert shaft <NUM> through a sheath <NUM>, while manipulating the distal end of the shaft <NUM> using a manipulator <NUM> near the proximal end of the catheter <NUM> and/or deflection from the sheath <NUM>. As shown in an inset <NUM>, catheter <NUM> may be fitted at the distal end of shaft <NUM>. Catheter <NUM> may be inserted through sheath <NUM> in a collapsed state and may be then expanded within heart <NUM>. Catheter <NUM>, as set forth above, includes a plurality of electrodes 47A-N, as further disclosed herein.

According to exemplary embodiments, catheter <NUM> may be configured to map and/or ablate tissue areas of a cardiac chamber of heart <NUM>. Inset <NUM> shows catheter <NUM> in an enlarged view, inside a cardiac chamber of heart <NUM>. As shown, catheter <NUM> includes a plurality of electrodes 47A-N coupled onto the body of the catheter <NUM>. According to other exemplary embodiments, multiple elements may be connected via splines that form the shape of the catheter <NUM>. One or more other elements (not shown) may be provided and may be any elements configured to ablate or to obtain biometric data and may be electrodes, transducers, or one or more other elements.

According to exemplary embodiments disclosed herein, the electrodes, such as electrodes 47A-N, may be configured to provide energy to tissue areas of an intra-body organ such as heart <NUM>. The energy may be thermal energy and may cause damage to the tissue area starting from the surface of the tissue area and extending into the thickness of the tissue area.

According to exemplary embodiments disclosed herein, biometric data may include one or more of LATs, electrical activity, topology, bipolar mapping, dominant frequency, impedance, or the like. The local activation time may be a point in time of a threshold activity corresponding to a local activation, calculated based on a normalized initial starting point. Electrical activity may be any applicable electrical signals that may be measured based on one or more thresholds and may be sensed and/or augmented based on signal to noise ratios and/or other filters. A topology may correspond to the physical structure of a body part or a portion of a body part and may correspond to changes in the physical structure relative to different parts of the body part or relative to different body parts. A dominant frequency may be a frequency or a range of frequency that is prevalent at a portion of a body part and may be different in different portions of the same body part. For example, the dominant frequency of a pulmonary vein of a heart may be different than the dominant frequency of the right atrium of the same heart. Impedance may be the resistance measurement at a given area of a body part.

As shown in <FIG>, the probe <NUM>, and catheter <NUM> may be connected to a console <NUM>. Console <NUM> may include a processor <NUM>, such as a general-purpose computer, with suitable front end and interface circuits <NUM> for transmitting and receiving signals to and from catheter, as well as for controlling the other components of system <NUM>. In some exemplary embodiments, processor <NUM> may be further configured to receive biometric data, such as electrical activity, and determine if a given tissue area conducts electricity. According to an exemplary embodiment, the processor may be external to the console <NUM> and may be located, for example, in the catheter, in an external device, in a mobile device, in a cloud-based device, or may be a standalone processor.

As noted above, processor <NUM> may include a general-purpose computer, which may be programmed in software to carry out the functions described herein. The software may be downloaded to the general-purpose computer in electronic form, over a network, for example, or it may, alternatively or additionally, be provided and/or stored on non-transitory tangible media, such as magnetic, optical, or electronic memory. The example configuration shown in <FIG> may be modified to implement the exemplary embodiments disclosed herein. The disclosed exemplary embodiments may similarly be applied using other system components and settings. Additionally, system <NUM> may include additional components, such as elements for sensing electrical activity, wired or wireless connectors, processing and display devices, or the like.

According to an embodiment, a display connected to a processor (e.g., processor <NUM>) may be located at a remote location such as a separate hospital or in separate healthcare provider networks. Additionally, the system <NUM> may be part of a surgical system that is configured to obtain anatomical and electrical measurements of a patient's organ, such as a heart, and performing a cardiac ablation procedure. An example of such a surgical system is the Carto® system sold by Biosense Webster.

The system <NUM> may also, and optionally, obtain biometric data such as anatomical measurements of the patient's heart using ultrasound, computed tomography (CT), magnetic resonance imaging (MRI) or other medical imaging techniques known in the art. The system <NUM> may obtain electrical measurements using catheters, electrocardiograms (EKGs) or other sensors that measure electrical properties of the heart. The biometric data including anatomical and electrical measurements may then be stored in a memory <NUM> of the mapping system <NUM>, as shown in <FIG>. The biometric data may be transmitted to the processor <NUM> from the memory <NUM>. Alternatively, or in addition, the biometric data may be transmitted to a server <NUM>, which may be local or remote, using a network <NUM>.

Network <NUM> may be any network or system generally known in the art such as an intranet, a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), a direct connection or series of connections, a cellular telephone network, or any other network or medium capable of facilitating communication between the mapping system <NUM> and the server <NUM>. The network <NUM> may be wired, wireless or a combination thereof. Wired connections may be implemented using Ethernet, Universal Serial Bus (USB), RJ-<NUM> or any other wired connection generally known in the art. Wireless connections may be implemented using Wi-Fi, WiMAX, and Bluetooth, infrared, cellular networks, satellite or any other wireless connection methodology generally known in the art. Additionally, several networks may work alone or in communication with each other to facilitate communication in the network <NUM>.

In some instances, the server <NUM> may be implemented as a physical server. In other instances, server <NUM> may be implemented as a virtual server a public cloud computing provider (e.g., Amazon Web Services (AWS) ®).

Control console <NUM> may be connected, by a cable <NUM>, to body surface electrodes <NUM>, which may include adhesive skin patches that are affixed to the patient <NUM>. The processor, in conjunction with a current tracking module, may determine position coordinates of the catheter <NUM> inside the body part (e.g., heart <NUM>) of a patient. The position coordinates may be based on impedances or electromagnetic fields measured between the body surface electrodes <NUM> and the electrode <NUM> or other electromagnetic components of the catheter <NUM>. Additionally or alternatively, location pads may be located on the surface of bed <NUM> and may be separate from the bed <NUM>.

Processor <NUM> may comprise real-time noise reduction circuitry typically configured as a field programmable gate array (FPGA), followed by an analog-to-digital (A/D) ECG (electrocardiograph) or EMG (electromyogram) signal conversion integrated circuit. The processor <NUM> may pass the signal from an A/D ECG or EMG circuit to another processor and/or can be programmed to perform one or more functions disclosed herein.

Control console <NUM> may also include an input/output (I/O) communications interface that enables the control console to transfer signals from, and/or transfer signals to electrodes 47A-N.

During a procedure, processor <NUM> may facilitate the presentation of a body part rendering <NUM> to physician <NUM> on a display <NUM>, and store data representing the body part rendering <NUM> in a memory <NUM>. Memory <NUM> may comprise any suitable volatile and/or non-volatile memory, such as random-access memory or a hard disk drive. In some exemplary embodiments, medical professional <NUM> may be able to manipulate a body part rendering <NUM> using one or more input devices such as a touch pad, a mouse, a keyboard, a gesture recognition apparatus, or the like. For example, an input device may be used to change the position of catheter <NUM> such that rendering <NUM> is updated. In alternative exemplary embodiments, display <NUM> may include a touchscreen that can be configured to accept inputs from medical professional <NUM>, in addition to presenting a body part rendering <NUM>.

As shown in the process flow chart <NUM> of <FIG>, at step <NUM>, a plurality of electronic signals may be received from a respective plurality of electrodes. The plurality of electrodes may be attached to or part of one or more catheters. The one or more catheters may be inserted into an intra-body organ via an incision or via a natural orifice and may be directed to the intra-body organ. The plurality of electrodes may transmit electronic signals (e.g., voltage signals) to a processor (e.g., processor <NUM> of <FIG>) via a wired or wireless connection. The processor may calculate impedance values based on the electronic signals provided by the plurality of electrodes and the impedance values may be applied to determine if the catheter or, more specifically, one or more of the plurality of electrodes are proximate (e.g., in contact) with the tissue of the intra-body organ, as further disclosed herein.

The plurality of electronic signals sensed by respective plurality of electrodes may be provided to/received by a location agnostic system. A location agnostic system may be any applicable system that is not aware of the location of the plurality of electrodes within the intrabody organ. The location agnostic system may include a processor (e.g., processor <NUM> of <FIG>), a memory, and other components configured to at least determine proximity in accordance with the techniques disclosed herein. As an example, as shown in <FIG>, the one or more catheters <NUM> inserted into an intra-body organ <NUM> that provide the respective plurality of electronic signals may have one hundred twenty (<NUM>) electrodes <NUM>. The electronic signals <NUM> sensed by the one hundred twenty electrodes <NUM> may be provided to a location agnostic system <NUM> such that the location agnostic system <NUM> is configured to receive and process all one hundred twenty electronic signals <NUM> corresponding to the one hundred and twenty electrodes.

At step <NUM> of the process <NUM> of <FIG>, a subset of the plurality of electronic signals sensed by the plurality of electrodes may be split and may be provided to a location aware system. Accordingly, the plurality of electronic signals may be provided to the location agnostic system, as described at step <NUM>, and a subset of the plurality of electronic signals may be provided to both the location agnostic system (i.e., as described at step <NUM>, as part of the plurality of electronic signals) and to the location aware system (i.e., as described in this step <NUM>). Continuing the example provided herein, as shown in <FIG>, of the one hundred twenty electronic signals <NUM> that are provided to the location agnostic system <NUM>, a subset <NUM> of twenty-two (<NUM>) electronic signals may be split such that they are also provided to a location aware system <NUM>.

As described herein, a location agnostic system <NUM> may not receive or otherwise generate location information corresponding to the one or more catheters within an intra-body organ. Accordingly, the location agnostic system <NUM> may not be able to determine if a catheter or, more specifically, one or more electrodes are proximate to (e.g., in contact with) tissue of the intra-body organ. Notably, the location agnostic system <NUM> may not be able to determine if the catheter is proximate to such tissue without the location of the catheter because such proximity determinations may require location information to determine the correct impedance thresholds such that proximity can be determined based on whether received electronic signals meet the location specific impedance thresholds for tissue at the location.

At step <NUM> of the process <NUM> of <FIG>, a location of a catheter and, more specifically, of one or more electrodes may be determined by the location aware system. The location of the catheter may be determined based on one or more of electromagnetic transmissions, body surface electrodes, a location pad, a mapping system, or the like. For example, the location aware system may be configured to receive electromagnetic signals between a catheter and a location pad and, based on the electromagnetic signals, may determine the catheter's location. As another example, the location aware system may compare electromagnetic signals from the catheter to body surface electrode signals to determine the catheter's location relative to the body surface electrodes. Continuing the example, as shown in <FIG>, the location aware system <NUM> may determine the location of the one or more catheters <NUM>.

At step <NUM> of the process <NUM> of <FIG>, a determination that the catheter and, more specifically, one or more electrodes, is proximate to (e.g., in contact with) the tissue of the intra-body organ may be made by the location aware system. The determination that the catheter is proximate to the tissue of the intra-body organ may be based on the location of the catheter and an impedance determined based on the electrical signals sensed by the one or more electrodes. Notably, an impedance threshold may be determined based on the location of the catheter, as provided by the location aware system. The impedance threshold may be specific to the tissue at the location of the catheter such that a proximity determination can be made based on the location specific impedance threshold. The location aware system may determine that the catheter is proximate to (e.g., in contact with) the tissue of the intra-body organ based on the applicable location specific impedance threshold and the impedance value sensed by one or more of the electrodes, such that the impedance value exceeds the location specific impedance threshold to indicate proximity (e.g., contact).

At step <NUM> of the process <NUM> of <FIG>, a location agnostic system profile for the catheter may be generated based on the proximity determination by the location aware system at step <NUM>. Notably, when the location aware system determines that a catheter is proximate to (e.g., in contact with) tissue, at step <NUM>, the location agnostic system may also determine impedance values based on electrical signals sensed by the one or more electrodes. The location agnostic system may generate a location agnostic system profile based on such impedance values such that the profile includes the impedance values determined by the location agnostic system while the location aware system generates a proximity determination.

<FIG> shows an example illustration for generating a location agnostic system profile. As shown in <FIG>, a catheter <NUM> comprising a plurality of electrodes 405a-405n may be inserted into a heart chamber <NUM>. Electronic signals <NUM> from the plurality of electrodes 405a-405n may be provided to location agnostic system <NUM>. Additionally, a subset <NUM> of the electronic signals from the plurality of electrodes 405a-405n may be provided to a location aware system <NUM>.

The location aware system <NUM> is aware of the location of the catheter <NUM> and, based on the location of the catheter <NUM>, applies an impedance threshold to determine proximity (e.g., contact) with the tissue of the heart chamber <NUM>. The location aware system <NUM> determines that the subset of the electronic signals from the plurality of electrodes 405a-405n are in contact with the surface of tissue in the heart chamber <NUM>, at a first time, based on a change in impedance values such that the change in impedance values exceeds the threshold impedance. The location aware system <NUM> provides a contact indication <NUM> to the location agnostic system <NUM> upon determining contact with the intra-body organ tissue. According to an implementation, the percentage of change in impedance may be applied when determining if an impedance value exceeds the threshold impedance. Upon detection of the contact, the location agnostic system <NUM> records the impedance values sensed by the plurality of electrodes 405a-405n at the first time. Notably, the impedance values determined by the location aware system <NUM> may differ from the impedance values determined by the location agnostic system <NUM> at the first time. However, based on the contact determination by the location aware system <NUM>, the impedance values determined by the location agnostic system <NUM> for the plurality of electrodes 405a-405n are stored as the location agnostic system profile <NUM> such that subsequent determination of impedance values that meet the location agnostic system profile are marked as contact with the tissue at the location.

At a second time, after the first time, the location agnostic system <NUM> may apply the location agnostic system profile to determine if the plurality of electrodes 405a-405n are in contact with the surface of tissue of the heart chamber <NUM>. For example, the location agnostic system profile may be applied to a set of electrical signals received by the location agnostic system <NUM> at the second time. Electrodes that sense electronic signals that correspond to impedance values greater than those in the location agnostic system profile may be determined to be in contact with the tissue of heart organ <NUM>. Electronic signals that correspond to impedance values greater than those in the location agnostic system profile may be considered to meet the location agnostic system profile such that they exceed impedance thresholds as provided in the location agnostic system profile.

After the determination of the location agnostic system profile, the location aware system <NUM> may not be needed to determine contact with the tissue surface of the heart chamber <NUM> at the location. According to an exemplary embodiment of the present invention, the location aware system <NUM> may be disconnected at the second time such that electrical signals from the plurality of electrodes are only provided to the location agnostic system <NUM>. Based on the process <NUM> of <FIG>, a number of location agnostic system profiles may be generated and stored in memory for a number of different locations.

<FIG> shows a graph <NUM> corresponding to voltages detected by the location agnostic system <NUM> of <FIG> and <FIG> shows a graph <NUM> corresponding to voltages detected by the location aware system <NUM> of <FIG>. Although graphs <NUM> and <NUM> show the voltage corresponding to a single electrical signal from a single electrode, it will be understood that multiple electronic signals may be used to determine a location agnostic system profile.

As shown in <FIG>, the voltage difference determined by the location aware system <NUM> shown in graph <NUM> may be <NUM> volts when the location aware system <NUM> determines that the corresponding electrode is in contact with the tissue surface of the heart organ <NUM> of <FIG>, based on a location specific impedance threshold. The corresponding voltage difference determined by the location agnostic system <NUM> may be <NUM> volts at the same time. Accordingly, a location agnostic system profile may be determined such that a <NUM> volt difference determined by the location agnostic system at the location may correspond a contact with the tissue of the heart organ <NUM>, as determined by the location agnostic system.

Notably, a location aware system (e.g., <NUM> of <FIG>) may determine that a subset of electrodes are proximate to (e.g., in contact with) tissue of an intra-body organ at a specific location. The determination may be made based on the subset of electrodes sensing an impedance value (e.g., current and voltage) that exceeds the impedance threshold for that specific location, as determined by the location aware system. A location agnostic system (e.g., <NUM> of <FIG>) may also sense impedance values by the entire set of electrodes (i.e., a greater number of electrode based electrical signals than those provided to the location aware system). Based on the proximity determined by the location aware system, the location agnostic system may generate a location agnostic contact profile such that the impedance values determined by the location agnostic system, when the location aware system indicates proximity, are recorded as the impedance values that indicate contact for the location agnostic system. As noted herein, such one or more impedance values of a location agnostic contact profile may be different for the location agnostic system than those sensed by the location aware system (e.g., <FIG>), even when the same signals are provided to the two different systems (e.g., <FIG>). The differences may be due to any applicable reason such as circuitry, electricity propagation, internal components, conversion mechanisms, or the like. Accordingly, a location agnostic contact profile with at least one impedance threshold may be generated for the location agnostic system and may be used to determine proximity of the one or more catheters, by the location agnostic system, at the specific location.

Proximity (e.g., contact) indicated by the location agnostic system based on a location agnostic system profile may be used to map the surfaces of all or a part of an intra-body organ such as a heart chamber. Alternatively, or in addition, proximity indicated by the location agnostic system may be used to initiate ablation by an ablation electrode during a medical procedure.

Any of the functions and methods described herein can be implemented in a general-purpose computer, a processor, or a processor core. Suitable processors include, by way of example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), and/or a state machine. Such processors can be manufactured by configuring a manufacturing process using the results of processed hardware description language (HDL) instructions and other intermediary data including netlists (such instructions capable of being stored on a computer-readable media). The results of such processing can be maskworks that are then used in a semiconductor manufacturing process to manufacture a processor which implements features of the disclosure.

Any of the functions and methods described herein can be implemented in a computer program, software, or firmware incorporated in a non-transitory computer-readable storage medium for execution by a general-purpose computer or a processor. Examples of non-transitory computer-readable storage mediums include a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs).

Claim 1:
A system (<NUM>) for determining a tissue contact profile for determining proximity of a catheter to tissue, the system comprising:
a catheter (<NUM>) comprising a plurality of electrodes (<NUM>) configured to sense a first plurality of electronic signals within an intra-body organ;
a location aware system (<NUM>) configured to:
receive a subset of electronic signals from the first plurality of electronic signals;
determine an impedance value based on the subset of electronic signals;
determine that the impedance value is greater than an impedance value threshold of the location;
determine a location of the catheter within the intra-body organ; and
determine that the catheter is in contact with intra-body organ tissue at the location, based on the subset of electronic signals and at least one tissue property at the location, wherein the tissue property is an impedance threshold for the location;
a location agnostic system (<NUM>) configured to:
receive the first plurality of electronic signals each from the respective plurality of electrodes of the catheter; and
generate, at a first time, the tissue contact profile for determining proximity to tissue for the catheter based on the determination, by the location aware system, that the catheter is in contact with the tissue at the location,
wherein the tissue contact profile comprises impedance values determined by the location agnostic system for the plurality of electrodes when the location aware system has determined that the catheter is in contact with the tissue at the location.