# US 2010/0168550 A1 · Multiple shell construction to emulate chamber contraction with a mapping system

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- Number: US 2010/0168550 A1
- Document ID: US20100168550A1
- Status: Published application
- Kind: A1
- Application number: 12/347,216
- Filed: 2008-12-31
- Published: 2010-07-01
- Earliest claimed: 2008-12-31
- Assignees: St. Jude Medical, Atrial Fibrillation Division, Inc.
- Inventors: Israel A. Byrd; Dale Just
- Web page: https://patentgrep.com/patent/US20100168550A1

## CPC

- A61B 5/1076: {for measuring dimensions inside body cavities, e.g. using catheters (A61B3/1005 takes precedence)}
- A61B 5/0006: {ECG or EEG signals}
- A61B 5/063: {using impedance measurements}
- A61B 5/287: Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
- A61B 5/308: for electrocardiography [ECG]
- A61B 5/349: Detecting specific parameters of the electrocardiograph cycle
- A61B 5/6885: {Monitoring or controlling sensor contact pressure}
- A61B 5/7289: {Retrospective gating, i.e. associating measured signals or images with a physiological event after the actual measurement or image acquisition, e.g. by simultaneously recording an additional physiological signal during the measurement or image acquisition}
- A61B 5/06: Devices, other than using radiation, for detecting or locating foreign bodies {; Determining position of diagnostic devices within or on the body of the patient}
- A61B 5/282: Holders for multiple electrodes (for introduction into the body A61B5/287)
- A61B 5/341: Vectorcardiography [VCG]
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

A system for constructing multiple shells (electronic models) indicative of the geometry and/or volume of a bodily lumen, such as a heart chamber, is configured to collect a plurality of location data points as the electrode is swept within the chamber. Each of the collected data points has an associated measured cardiac phase at which such point was acquired. The system is configured to segregate the collected electrode locations into sets based on the phase. Each set is characterized by a particular, associated phase of its constituent electrode locations. The system is configured to generate, for each set, a respective shell that will represent the chamber at the associated phase. The shells, once constructed, may be used for or in connection with a variety of diagnostic, mapping, and/or therapeutic procedures. The system is also configured to verify that the electrode is in contact with the heart tissue before using the collected data point in the shell construction (e.g., using a phase angle parameter to verify contact).

## Claims

### Claim 1

A method of processing information, comprising the steps of:
collecting, for at least one sensor, a plurality of sensor locations as the at least one sensor is swept within a heart chamber of a patient;
segregating the collected sensor locations into a plurality of sets in accordance with a respective phase of a cardiac cycle during or at which each sensor location was collected, each set having associated therewith a predetermined phase of the cardiac cycle; and
generating, for each set, a respective geometry of the heart chamber at the associated phase of the cardiac cycle.

### Claim 2 (depends on 1)

The method of claim 1 further including the step of:
determining if the sensor is in contact with tissue of the heart chamber.

### Claim 3 (depends on 2)

The method of claim 2 further comprising the step of forming the sensor by providing a coil configured to detect a magnetic field.

### Claim 4 (depends on 3)

The method of claim 3 wherein said forming step further includes the sub-step of providing a catheter with a distal tip electrode wherein the sensor magnetic coil and the distal tip electrode have a geometrical relationship therebetween, and wherein said generating step includes the substep of computing, for at least one of the sets containing phase-associated sensor locations, a plurality of distal tip locations using the sensor locations in accordance with the geometrical relationship.

### Claim 5 (depends on 2)

The method of claim 2 further comprising the step of forming the sensor by providing an electrode.

### Claim 6 (depends on 5)

The method of claim 5 wherein said determining tissue contact step includes the substeps of:
supplying an excitation signal to the electrode;
measuring a complex impedance of the tissue proximate the electrode; and
determining when the electrode is in contact with the tissue when a component of the measured complex impedance meets predetermined criteria.

### Claim 7 (depends on 6)

The method of claim 6 wherein said step of measuring the complex impedance includes the sub-step of sensing an induced signal produced in response to the excitation signal between the electrode and a patch affixed to the patient.

### Claim 8 (depends on 7)

The method of claim 7 wherein the sub-step of sensing the induced signal includes measuring the induced signal between the electrode and a patch affixed to the patient.

### Claim 9 (depends on 5)

The method of claim 5 wherein said generating step includes the substeps of:
qualifying locations that have been determined to have been collected when the electrode was in contact with tissue of the heart chamber; and
constructing the respective geometries using qualified electrode locations.

### Claim 10 (depends on 1)

The method of claim 1 further including the step of:
displaying the plurality of geometries in accordance with a measured phase of the patient's cardiac cycle.

### Claim 11 (depends on 10)

The method of claim 10 further including the steps of:
acquiring electrophysiologic (EP) data associated with the heart chamber; and
mapping the acquired EP data on the plurality of geometries.

### Claim 12 (depends on 11)

The method of claim 11 wherein said EP data comprises electrical activation potential values corresponding to physiological electrical activity.

### Claim 13 (depends on 12)

The method of claim 12 wherein the step of acquiring EP data includes the sub-step of acquiring an EP data point at a first phase of the cardiac cycle, and wherein said mapping step includes the sub-step of associating the acquired EP data point to the same anatomic location on both a first one of the geometries corresponding to the first phase and on a second one of the geometries corresponding to a second phase of the cardiac cycle different from the first phase.

### Claim 14 (depends on 13)

The method of claim 13 further comprising the steps of:
determining respective positions on the first and second geometries that define the same anatomic location; and
mapping the acquired EP data point to the respective positions.

### Claim 15 (depends on 14)

The method of claim 14 wherein said step of determining respective positions include the sub-step of:
defining a least squares regression through corresponding points in said shells.

### Claim 16 (depends on 1)

The method of claim 1 further including the steps of:
acquiring cardiac phase information; and
associating the acquired cardiac phase information with the collected sensor locations by synchronizing the respective times during or at which the sensor locations were collected and the phase information was acquired.

### Claim 17 (depends on 16)

The method of claim 16 wherein said acquiring step includes the substeps of:
providing a plurality of body surface electrodes on the patient for acquiring respective body surface electrograms;
selecting one or more of the body surface electrograms in accordance with predetermined selection criteria;
processing the selected body surface electrograms to obtain the cardiac phase.

### Claim 18 (depends on 17)

The method of claim 17 wherein the predetermined selection criteria includes at least one from the group comprising a target heart chamber whose geometry is to be determined and a disease state of the patient's heart.

### Claim 19 (depends on 16)

The method of claim 16 wherein said acquiring step includes the substep of:
providing a reference electrode fixed in location in the heart configured to produce a signal indicative of the phase of the cardiac cycle.

### Claim 20 (depends on 1)

The method of claim 1 wherein said segregating step comprises the substep of:
identifying, for each cardiac phase for which a set is to be produced, the outermost collected sensor locations.

### Claim 21 (depends on 1)

The method of claim 1 further comprising the steps of:
forming the sensor by providing a plurality of electrodes on a distal end of a catheter;
obtaining location information from one or more of the electrodes;
computing a distal location of the catheter using the collected location information in accordance with a geometrical relationship between the one or more electrodes from which location information is obtained and the distal location of the catheter; and
defining the collected sensor location as corresponding to the computed distal location of the catheter.

### Claim 22

A system for processing information, comprising:
means for collecting, for at least one sensor, a plurality of sensor locations as the at least one sensor is swept within a heart chamber of a patient;
means for segregating the collected sensor locations into a plurality of sets in accordance with a respective phase of a cardiac cycle during or at which each sensor location was collected, each set having associated therewith a predetermined phase of the cardiac cycle; and
means for generating, for each set, a respective geometry of the heart chamber at the associated phase of the cardiac cycle.

### Claim 23

A system for processing information, comprising:
a processing apparatus configured to collect, for at least one sensor, a plurality of sensor locations as the at least one sensor is swept within a heart chamber of a patient, said processing apparatus being further configured to segregate the collected sensor locations into a plurality of sets in accordance with a respective phase of a cardiac cycle during or at which each sensor location was collected, each set having associated therewith a predetermined phase of the cardiac cycle, said apparatus being further configured to generate, for each set, a respective geometry of the heart chamber at the associated phase of the cardiac cycle.

### Claim 24 (depends on 23)

The system of claim 23 further including a display, said processing apparatus being further configured to display the plurality of geometries in accordance with a measured phase of the patient's cardiac cycle.

### Claim 25 (depends on 24)

The system of claim 24 wherein said processing apparatus is further configured to superimpose a representation of a catheter on said display of the plurality of geometries.

### Claim 26 (depends on 25)

The system of claim 25 wherein said processing apparatus is further configured to track movement of the catheter, said processing apparatus being further configured to synchronize the movement of the catheter to the display of the plurality of geometries.

### Claim 27 (depends on 23)

The system of claim 23 further including the steps of:
acquiring electrophysiologic (EP) data associated with the heart chamber; and
mapping the acquired EP data on the plurality of geometries.

### Claim 28 (depends on 27)

The method of claim 27 wherein said EP data comprises electrical activation potential values corresponding to physiological electrical activity.