# US 12,004,822 B2 · System and method for determining a configuration of an expandable portion > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,004,822 B2 - Document ID: US12004822B2 - Status: Granted - Kind: B2 - Application number: 17/964,830 - Filed: 2022-10-12 - Published: 2023-02-02 - Granted: 2024-06-11 - Earliest claimed: 2015-03-31 - Assignees: Medtronic Navigation, Inc. - Applicants: Medtronic Navigation, Inc. - Inventors: Brad Jacobsen; Bruce M. Burg; Andrew Bzostek - Web page: https://patentgrep.com/patent/US12004822B2 ## CPC - A61B 34/20: Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis - A61B 5/062: {using magnetic field} - A61B 5/6853: {with a balloon} - A61B 2017/00725: {Calibration or performance testing} - A61B 2017/00862: {elastic or resilient} - A61B 2034/2046: {Tracking techniques} - A61B 2034/2051: {Electromagnetic tracking systems} - A61B 2034/2068: {using pointers, e.g. pointers having reference marks for determining coordinates of body points} - A61M 2025/0166: {Sensors, electrodes or the like for guiding the catheter to a target zone, e.g. image guided or magnetically guided} - A61M 2205/3317: Electromagnetic, inductive or dielectric measuring means - A61N 2/006: {for magnetic stimulation of nerve tissue} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) ## Abstract Disclosed is a system and method for determining a location and configuration of an expandable member. A flexible coil can be provided on a shape changing portion, such as the expandable member, to measure a signal as the shape changes. ## Claims ### Claim 1 A system for determining a configuration of an expandable portion, comprising: an instrument extending along a longitudinal axis and having a first end and a second end and an expandable portion between the first end and the second end; a sensing member positioned with the expandable portion of the instrument and configured to change configuration with the expandable portion; wherein the expandable portion is configured to change from a first configuration to a second configuration; wherein the sensing member is configured to sense a field generated with a localizer and generate a signal based on the sensed field; wherein the sensing member is formed around the longitudinal axis and with the expandable member in a wave pattern, where a transverse distance that is transverse to the longitudinal axis of two adjacent transverse peaks varies from the first configuration to the second configuration. ### Claim 2 (depends on 1) The system of claim 1, further comprising: a localizer configured to generate the field. ### Claim 3 (depends on 1) The system of claim 1, further comprising: a tracking processor configured to execute instructions to determine at least one of a size or a shape of the sensing member based on the signal. ### Claim 4 (depends on 1) The system of claim 1, wherein the expandable portion is a balloon having a wall; wherein the sensing member is formed in the wall. ### Claim 5 (depends on 1) The system of claim 1, further comprising: a tracking member configured to sense the field and generate a tracking signal based on the sensed field to determine a location of the expandable portion. ### Claim 6 (depends on 3) The system of claim 3, further comprising: a memory configured to store a look up table of at least one configuration, including size and shape, of the expandable member; wherein the tracking processor is configured to execute instructions to determine at least the size or the shape of the sensing member based on the sensed field to compare the signal from the sensing member to a stored signal in the look up table to determine at least one of the size or the shape of the expandable member. ### Claim 7 (depends on 6) The system of claim 6, wherein the tracking processor is further configured to execute instructions to interpolate from at least one stored signal to determine at least one of the size or the shape of the expandable member. ### Claim 8 (depends on 1) The system of claim 1, wherein the sensing member includes a coil of conductive material formed with the expandable member; wherein the coil of conductive material is formed around a perimeter of the expandable member. ### Claim 9 (depends on 8) The system of claim 8, wherein the coil includes the wave pattern wound around the expandable member and is able to vary configuration with the expandable member. ### Claim 10 A system for determining a configuration of an expandable portion, comprising: a field generating coil configured to generate an electromagnetic field; an instrument having a shape changing portion configured to change configuration during a procedure; a flexible coil formed from a flexible conductive wire wrapped around the shape changing portion, wherein the flexible coil is configured to sense the electromagnetic field generated with the field generating coil and generate a signal based on the sensed electromagnetic field; a memory system having stored therein a look-up table of at least one predetermined configuration, including shape or size, of the shape changing portion; and a navigation processor configured to execute instructions to access the look-up table to determine a current configuration of the shape changing portion based on the sensed field; wherein the sensed electromagnetic field of the flexible coil varies upon the shape changing portion changing from a first configuration to a second configuration. ### Claim 11 (depends on 10) The system of claim 10, further comprising: a display device configured to display a representation of the determined current configuration. ### Claim 12 (depends on 10) The system of claim 10, wherein the navigation processor is further configured to determine a location of the shape changing portion; wherein the display device is configured to display the location and the determined current configuration simultaneously. ### Claim 13 (depends on 11) The system of claim 11, further comprising: an imaging system configured to acquire image data for display as an image with the display device; wherein the representation is configured to be superimposed on the image. ### Claim 14 (depends on 10) The system of claim 10, wherein the flexible coil is configured to change from a first coil configuration to a second coil configuration based on the first configuration or the second configuration. ### Claim 15 (depends on 14) The system of claim 14, wherein the shape changing portion includes a first shape changing portion and a second shape changing portion; wherein the flexible coil is wrapped around the first shape changing portion and second flexible coil is wrapped around the second shape changing portion. ### Claim 16 (depends on 10) The system of claim 10, wherein the flexible coil includes a wave pattern wound around the shape changing portion; wherein the flexible coil is configured to allow the shape changing portion to freely change shape. ### Claim 17 A method of determining a configuration of an expandable portion, comprising: positioning an expandable coil formed from a flexible conductive wire with an expandable member in an area of an instrument; providing the expandable coil to generate a signal due to an electromagnetic field in which the expandable coil is configured to be placed; and determining at least one of a current size or a current configuration of the expandable member due to the generated signal; wherein a flux from the electromagnetic field through the expandable coil varies upon the expandable member changing from a first configuration to a second configuration. ### Claim 18 (depends on 17) The method of claim 17, further comprising: saving a look-up table of a plurality of possible shapes and sizes of the expandable member and a related signal generated by the expandable coil; wherein determining the current size and the current configuration of the expandable member includes comparing a current signal to the look-up table. ### Claim 19 (depends on 18) The method of claim 18, further comprising: iterating interpolating between two signal values in the look-up table to determine the current shape and the current size of the expandable member. ### Claim 20 (depends on 19) The method of claim 19, further comprising: configuring the expandable member to change configuration and thereby effect the configuration of the expandable coil.