# US 2014/0191757 A1 · Radiofrequency Coils > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0191757 A1 - Document ID: US20140191757A1 - Status: Published application - Kind: A1 - Application number: 14/148,900 - Filed: 2014-01-07 - Published: 2014-07-10 - Earliest claimed: 2013-01-08 - Assignees: Pulseteq Limited - Applicants: PulseTeq Ltd - Inventors: Chris Randell - Web page: https://patentgrep.com/patent/US20140191757A1 ## CPC - G01R 33/34007: {Manufacture of RF coils, e.g. using printed circuit board technology; additional hardware for providing mechanical support to the RF coil assembly or to part thereof, e.g. a support for moving the coil assembly relative to the remainder of the MR system} - G01R 33/34046: {Volume type coils, e.g. bird-cage coils; Quadrature bird-cage coils; Circularly polarised coils} - Y10T 29/4902: Electromagnet, transformer or inductor - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The present disclosure provides a method for producing a rigid, shaped, non-planar radiofrequency coil including: a) placing a number of coil elements selected from one and a desired plurality of coil elements on to a flexible substrate to make a coil; b) laying the coil flat and covering it with foam; c) and subsequently applying the foam covered coil to a first mechanical former capable of holding the coil rigid in a desired configuration. ## Claims ### Claim 1 A method for producing a rigid, shaped, non-planar radiofrequency coil comprising the steps of: a) placing a number of coil elements selected from one and a desired plurality of coil elements on to a flexible substrate to make a coil; b) laying the said coil flat and covering it with foam; c) and subsequently applying the said foam covered coil to a first mechanical former capable of holding the said coil rigid in a desired configuration. ### Claim 2 (depends on 1) A method according to claim 1, wherein the step of applying the foam covered coil to a first mechanical former is irreversible. ### Claim 3 (depends on 1) A method according to claim 1, wherein the step of applying the foam covered coil to a first mechanical former is reversible and the coil may be removed from the mechanical former using a quick release mechanism. ### Claim 4 (depends on 1) A method according to claim 1, wherein the method includes additional steps carried out prior to step (b) but subsequent to step (a), the additional steps comprising: a1) fitting the coil into a former, which may be the first mechanical former or a different former capable of holding the coil rigid and in the same shape as the first mechanical former; a2) while the coil is held in said former, undertaking a radiofrequency set-up to optimise the radiofrequency characteristics of the coil for the target application. ### Claim 5 (depends on 4) A method according to claim 4, wherein the radiofrequency set-up includes at least one of obtaining the best coil Q factor; ensuring that the coil has the most suitable unloaded resonance determined by measurement of the circuit's quality factor; ensuring that the coil is tuned at the nuclear magnetic resonance (NMR) frequency when loaded by the object that is to be the subject of the magnetic resonance (MR) scan; ensuring that in a multi-element design the coil has good radiofrequency isolation from other elements; ensuring that the coil is matched to the output circuitry such that, in the case of a receive coil, the signal detected has optimum signal to noise ratio, and, in the case of a transmit coil, that the coil produces an optimum radiofrequency field for a given radiofrequency power output from an associated amplifier. ### Claim 6 (depends on 1) A method according to claim 1, wherein the method includes a preliminary step performed prior to step (a), the preliminary step comprising: designing a former capable of holding a flexible coil in a rigid shape, this rigid shape being the shape required for the final coil. ### Claim 7 (depends on 6) A method according to claim 6, wherein the former is designed to be generally cylindrical in a mathematical sense with a uniform cross-section along its axis. ### Claim 8 (depends on 7) A method according to claim 7, wherein that cross-section is one of circular, oval or irregular. ### Claim 9 (depends on 6) A method according to claim 6, wherein the former is designed to be curved but not closed, such that the coil is held in a U- or C-shape or to extend significantly in two dimensions while having only a low profile in the third dimension. ### Claim 10 (depends on 1) A method according to claim 1, wherein the coil is provided with protrusions capable of reversibly locking into fixing locations on said former such that when the said protrusions are locked into the fixing locations the coil is held rigid in the desired configuration in the said former, the protrusions being designed to extend outside the sections of the coil that are foam covered. ### Claim 11 (depends on 10) A method according to claim 10, wherein the protrusions are provided on one or more edges of the coil and are permanently attached to the coil. ### Claim 12 (depends on 10) A method according to claim 10, wherein the protrusions may be removed from the coil for the foam covering step and attached once the coil is covered in foam. ### Claim 13 (depends on 12) A method according to claim 12, wherein the protrusions will be slid into mating parts on the coil or screwed onto the coil through holes in the foam. ### Claim 14 A rigid, shaped, non-planar radiofrequency coil, the coil comprising: a foam covered coil held rigid and in a desired conformation by a mechanical former. ### Claim 15 (depends on 14) A coil according to claim 14, wherein the coil is provided on a printed circuit board (PCB) allowing components to be flow soldered on to the PCB. ### Claim 16 (depends on 15) A coil according to claim 15, wherein the PCB is completely flexible or comprises a plurality of flat sections joined by flexible PCB material, or a first section comprising a plurality of flat sections joined by flexible PCB material and a second section that is completely flexible. ### Claim 17 (depends on 14) A coil according to claim 14, wherein the coil is provided separately from a preamplifier, such that a single set of preamplifiers may be used with several different sets of coils. ### Claim 18 (depends on 14) A coil according to claim 14, wherein the mechanical former is designed from a rigid material that is compatible with the coil and an MRI scanner, the rigid material selected from rapid prototype plastics material, vacuum cast material, injection moulded material, rim cast material, plastics machine cut parts, stiff foam pieces and/or a stiff plastics foam. ### Claim 19 (depends on 14) A coil according claim 14, wherein the mechanical former is shaped to allow the coil to be used on a person's head and or neck, the mechanical former being part of a frame which supports the said person's head and neck and the coil being removable from the frame without moving the person's head. ### Claim 20 (depends on 14) A coil according to claim 14, wherein the mechanical former is shaped to allow the coil to cover a focused region such as a person's forehead, the mechanical former being part of a frame that stabilises the said person's head. ### Claim 21 (depends on 20) A coil according to claim 20, wherein the mechanical former is provides a visual display to the person by means of goggles or mirrors. ### Claim 22 (depends on 14) A coil according to claim 14, wherein the coil is capable of splitting into sections. ### Claim 23 (depends on 14) A coil according to claim 14, wherein the coil may be made of more than one coil where each coil is for imaging nuclei of different chemical elements. ### Claim 24 (depends on 14) A coil according to claim 14, wherein the coil is selected from: a transmit coil, whereby the coil transmits the radiofrequency into the target region; a receive coil, whereby the coil receives the NMR signal; a transmit/receive coil, whereby the coil both transmits and receives the NMR signal; more than one coil element where one coil element is for transmitting radiofrequency waves and another coil element is for receiving radiofrequency waves. ### Claim 25 (depends on 14) A coil according to claim 14, wherein the coil includes at least one fiduciary marker incorporated into the final structure, where a fiduciary marker is an object placed in the field of view of the coil which appears in the final image produced and can be used as a point of reference. ### Claim 26 (depends on 14) A coil according to claim 14, wherein the coil includes reference samples incorporated into the final structure. ### Claim 27 (depends on 14) A coil according to claim 14, wherein the foam is non-conducting. ### Claim 28 (depends on 14) A coil according to claims 14, wherein the foam includes a conducting foam layer which can be used as a conducting radiofrequency screen. ### Claim 29 (depends on 14) A coil according to claim 14, wherein the foam covering is designed to act as an enclosure for one or more additional components of the radiofrequency coil, the one or more additional components being selected from preamplifiers, PIN diode controllers, radiofrequency circuitry for transmit/receive switching (T/R switches), radiofrequency combiners, radiofrequency splitters, and quadrature combiners. ### Claim 30 (depends on 14) A coil according to claim 14, wherein the coil produced is of a radiofrequency coil type adapted for use in MR scanners, the coil type being selected from single element coils, multi-element coils, birdcage coils, transverse electromagnetic (TEM) coils and microstrip coils.