# US 2013/0154779 A1 · Rotary transformer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0154779 A1 - Document ID: US20130154779A1 - Status: Published application - Kind: A1 - Application number: 13/769,062 - Filed: 2013-02-15 - Published: 2013-06-20 - Earliest claimed: 2007-12-20 - Assignees: Boston Scientific Scimed, Inc. - Inventors: Donald Masters; Stuart L. Carp; Peter Thornton - Web page: https://patentgrep.com/patent/US20130154779A1 ## CPC - H01F 21/06: by movement of core or part of core relative to the windings as a whole - A61B 8/12: in body cavities or body tracts, e.g. by using catheters - A61B 8/4461: {Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe} - H01F 38/18: Rotary transformers - A61B 2562/227: Sensors with electrical connectors - H01F 27/02: Casings - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract Described herein are rotary transformers for coupling signals between components that rotate relative to one another. In an exemplary embodiment, a rotary transformer comprises a rotary shaft, a first magnetic core on the rotary shaft, and a first winding wound around the first magnetic core. The rotary transformer farther comprises a hollow second magnetic core, and a second winding wound along the inner wall of the second magnetic core. During operation, the first winding on the rotary shaft rotates within the second winding with the magnetic cores magnetically coupling signals between the two windings. Also, the first and second windings are closely spaced to provide capacitive coupling between the windings that extends the frequency response of the transformer. In one embodiment, the windings comprises substantially flat conductors wound in the shape of the windings. In another embodiment, each of the windings comprises circular loops connected by jogs. ## Claims ### Claim 1 A rotary transformer, comprising: a rotary shaft; a first magnetic core on the rotary shaft; a first winding wound around the first magnetic core, wherein the first winding comprises a plurality of circular loops helically wound, wherein each of the plurality of circular loops is non-overlapping with each of the plurality of circular loops; a second magnetic core, wherein the second magnetic core is hollow; a second winding wound along an inner wall of the second magnetic core; and a housing, wherein the second magnetic core and second winding are housed in the housing, the rotary shaft, first magnetic core and first winding are rotatably housed the housing, and the first winding is rotatably disposed within the second magnetic core. ### Claim 2 (depends on 1) The rotary transformer of claim 1, wherein the first winding comprises a substantially fiat conductor wound around the first magnetic core. ### Claim 3 (depends on 2) The rotary transformer of claim 2, wherein the second winding comprises a substantially fiat conductor wound along the inner wall of the second core. ### Claim 4 (depends on 3) The rotary transformer of claim 3, wherein the second winding comprises a plurality of circular loops helically wound, wherein each of the plurality of circular loops of the second winding is non-overlapping with each of the plurality of circular loops of the second winding. ### Claim 5 (depends on 1) The rotary transformer of claim 1, wherein the first winding is wound around a rotational axis of the rotary shaft. ### Claim 6 (depends on 5) The rotary transformer of claim 5, wherein the second winding is wound around the rotational axis of the rotary shaft. ### Claim 7 (depends on 1) The rotary transformer of claim 1, further comprising a first magnetic core end on the rotary shaft located adjacent to the first magnetic core, wherein the first magnetic core end has a larger outer diameter than the first magnetic core. ### Claim 8 (depends on 7) The rotary transformer of claim 7, further comprising a second magnetic core end located adjacent to the second magnetic core, wherein the second magnetic core end is hollow and has a smaller inner diameter than the second magnetic core. ### Claim 9 (depends on 1) The rotary transformer of claim 1, further comprising first and second magnetic core ends, wherein the first and second magnetic cores are located between the first and second magnetic core ends. ### Claim 10 (depends on 1) The rotary transformer of claim 1, wherein the first and second windings have a different number of turns. ### Claim 11 A catheter system, comprising: a catheter body having a lumen; a work element rotatably received within the lumen of the catheter body; and a rotary transformer, comprising: a rotary shaft mechanically coupled to the work element; a first magnetic core on the rotary shaft; a first winding wound around the first magnetic core, wherein the first winding is electrically coupled to the work element and comprises a plurality of circular loops helically wound, wherein each of the plurality of circular loops is non-overlapping with each of the plurality of circular loops; a second magnetic core, wherein the second magnetic core is hollow; a second winding wound along an inner wall of the second magnetic core; and a housing, wherein the second magnetic core and second winding are housed in the housing, the rotary shaft, first magnetic core and first winding are rotatably housed in the housing, and the first winding is rotatably disposed within the second magnetic core. ### Claim 12 (depends on 11) The catheter system of claim 11, wherein the work element comprises an ultrasound transducer. ### Claim 13 (depends on 11) The catheter system of claim 11, wherein the first winding comprises a substantially flat conductor wound around the first magnetic core. ### Claim 14 (depends on 11) The catheter system of claim 11, wherein the second winding comprises a plurality of circular loops helically wound, wherein each of the plurality of circular loops of the second winding is non-overlapping with each of the plurality of circular loops of the second winding. ### Claim 15 (depends on 11) The catheter system of claim 11, wherein the first winding is wound around a rotational axis of the rotary shaft. ### Claim 16 (depends on 15) The catheter system of claim 15, wherein the second winding is wound around the rotational axis of the rotary shaft. ### Claim 17 (depends on 11) The catheter system of claim 11, further comprising a drive motor mechanically coupled to the rotary shaft. ### Claim 18 (depends on 11) The catheter system of claim 11, wherein the first and second windings have a different number of turns. ### Claim 19 A rotary transformer, comprising: a rotary shaft; a first magnetic core on the rotary shaft; a first winding wound around the first magnetic core; a second magnetic core, wherein the second magnetic core is hollow; a second winding wound along an inner wall of the second magnetic core, wherein the second winding comprises a plurality of circular loops helically wound, wherein each of the plurality of circular loops is non-overlapping with each of the plurality of circular loops; and a housing, wherein the second magnetic core and second winding are housed in the housing, the rotary shah, first magnetic core and first winding are rotatably housed in the housing, and the first winding is rotatably disposed within the second magnetic core. ### Claim 20 (depends on 19) A catheter system, comprising: a catheter body having a lumen; a work element rotatably received within the lumen of the catheter body; and the rotary transformer of claim 19, wherein the rotary shaft of the rotary transformer is mechanically coupled to the work element and the first winding of the rotary transformer is electrically coupled to the work element.