Koninklijke Philips Corporation N.v.

Jürgen Erwin Rahmer

Bernhard Gleich

Tim Nielsen

Ingo Schmale

Peter Vernickel

Michael Harald Kuhn

Ulrich Wolfgang Katscher

Jörn Borgert

Jurgen Weizenecker

Richard Moessel

Peter Boernert

Sascha Krueger

Peter Forthmann

Christian Stehning

Juergen Weizenecker

Stefanie Remmele

Tobias Richard Schaeffter

Ulrike Blume

A wireless passive marker device () to be tracked and a respective tracking system () are provided which make use of a sensing unit () comprising a resonator element () with piezoelectric properties and a coil element (), whereby an externally applied excitation field having a particular frequency is applied to act on the sensing unit () and wherein the sensing unit () responds to the externally applied excitation field by the resonator element () performing persisting mechanical oscillations in resonant mode, the persisting mechanical oscillations resulting in a piezoelectric voltage causing the coil element () to generate a magnetic field that may then be detected by the tracking system () and used for determining the position of the marker device () and/or sensing a physical property in the surrounding environment of the marker device ().

Passive wireless coil-based markers and tracking system

A system for receiving signals from a magneto-mechanical oscillator includes a main coil array adapted to receive a response signal of the magneto-mechanical oscillator and to transmit an excitation signal to the magneto-mechanical oscillator, and an additional coil for receiving a signal of the magneto-mechanical oscillator. A localizer is adapted to localize the additional coil and comprises a controller for controlling the main coil array and the additional coil such that a received localization signal is generated, a sensitivity provider for providing sensitivity information, and a processor for determining a position and/or orientation of the additional coil based on the provided sensitivity information and based on the received localization signal. A kit is provided for upgrading a system with a main coil array, by adding one or more additional coils and providing software for locating the one or more additional coils with the use of a pilot tone transmission.

System for receiving signals from a magneto-mechanical oscillator

A wireless pressure sensing unit () comprises a membrane () forming an outer wall portion of a cavity and two permanent magnets () inside the cavity. One magnet is coupled to the membrane, and at least one magnet is free to oscillate with a rotational movement. At least one is free to oscillate with a rotational movement. The oscillation takes place at a resonance frequency, which is a function of the sensed pressure, which pressure influences the spacing between the two permanent magnets. This oscillation frequency can be sensed remotely by measuring a magnetic field altered by the oscillation. The wireless pressure sensing unit may be provided on a catheter () or guidewire.

Pressure sensing unit, system and method for remote pressure sensing

The invention relates to a passive medical identification deviceto be used for identifying a medical tool such as, for example, a surgical instrument, if the medical tool is equipped with the identification device. The identification device comprises a casing, a magnetic objectarranged within the casing such that it is rotatable out of an equilibrium orientation by an external magnetic torque, and a restoring torque providersuch as, for example, a further magnetic object providing a restoring torque forcing the magnetic object back into the equilibrium orientation. The magnetic objectrotationally oscillates upon excitation by an external magnetic torque, thereby generating a response magnetic signal which is transduced into an induction signal that can provide a fingerprint specific for the respective identification device. Accordingly, the identity of the identification device and hence of the medical tool equipped with the identification device can be determined based on the induction signal.

Identifying system for identifying a medical tool like a surgical instrument

The present invention relates to an apparatus () for influencing and/or detecting magnetic particles in a field of view (), in particular an MPI apparatus. The apparatus comprises selection field elements () for generating a magnetic selection field (), drive field coils () for changing the position in space of the two sub-zones () by means of a magnetic drive field, focus field elements () for changing the position in space of the field of view () by means of a magnetic focus field, and receiving elements () for acquiring detection signals. A static system function of the apparatus is obtained in the absence of a magnetic focus field, from which an extended system function is generated by shifting a time-domain representation of said static system function proportional to the changes of the position of the field of view caused by appliance of the magnetic focus field. Said extended system function is then used for reconstructing the spatial distribution of the magnetic particles in the field of view from the detection signals.

MPI apparatus with fast field of view motion

An apparatus () detects magnetic particles in a field of view (). The apparatus includes selection and focus magnetic field coil pairs (), drive pairs (), and detection coils (). A computer is configured to receive background signals with the detection coils, controls current supplied to the drive coil pair to shift the field of view in space, and reconstruct detection signals from the detection coils into an image of the field of view (). The computer selects one or more frequency components of the detection signals and/or weighted by use of a frequency component specific signal quality factor obtained from the background signal measurements. Only the selected and/or weighted frequency components are used for reconstruction of the image.

Removal of background in MPI

A method for colon screening and collecting data by using Magnetic Particle Imaging wherein an imaging magnetic field is generated with a spatial distribution of the magnetic field strength such that the area of examination in the colon consists of a first sub-area with lower magnetic field strength, where the magnetization of a magnetic particle which was pre-delivered to the colon is not saturated, and a second sub-area with a higher magnetic field strength, where the magnetization of said magnetic particle is saturated. The spatial location of both sub-areas in the area of examination is modified so that the magnetization of said particles changes locally. Signals are acquired and are evaluated to obtain information about the spatial distribution of the signals in the area of examination. The method may be carried out during an entire peristaltic cycle in a colon portion or segment.

Colon screening by using magnetic particle imaging

A multimodal fiducial marker for registration of multimodal data, including a first portion comprising magnetic material visible in magnetic particle imaging (MPI) data obtained by a magnetic particle imaging method and a second portion comprising a second material visible in image data obtained by another imaging method, which image data is registrable with the MPI data and a corresponding marker arrangement.

Multimodal fiducial marker and marker arrangement

A system and method determines an isocenter for an imaging scan. The method includes receiving, by a control panel, patient data generated by at least one sensor, the patient data corresponding to dimensions of a body of a patient. The method includes generating, by the control panel, model data as a function of the patient data, the model data representing the body of the patient. The method includes receiving, by the control panel, a target location on the model data, the target location corresponding to a desired position on the body of the patient for performing the imaging scan. The method includes determining, by the control panel, an isocenter for the imaging scan as a function of the target location.

Visual pre-scan patient information for magnetic resonance protocol

A magnetic resonance system comprises a magnetic resonance scanner () including a main magnet () generating a static magnetic field biasing nuclear spins toward aligning along a direction of the static magnetic field, magnetic field gradient coils (), a radio frequency coil (), and a controller () configured to: (a) drive the radio frequency coil to selectively tip spins predominantly of short T2* out of the direction of the static magnetic field; (b) drive at least one of the magnetic field gradient coils and the radio frequency coil to dephase said spins predominantly of short T2* tipped out of the direction of the static magnetic field; and (c) drive the magnetic field gradient coils and the radio frequency coil to acquire magnetic resonance data that is predominantly T2* weighted due to preceding operations (a) and (b).

Flow insensitive magnetization preparation pulse for T2* contrast

An apparatus for detecting magnetic particles in a field of view, which apparatus includes selection coils, drive coils, receiving coils configured to acquire detection signals, and a processor configured to control the coils and reconstruct an image of the field of view from the detection signals. The processor is further configured to: identify in the detection signals one or more background time periods at which no magnetic particles were present in the field of view, wherein signal time periods at which magnetic particles were present in the field of view are interspersed with at least one of said one or more background time periods; use the detection signals obtained at the background time periods to correct detection signals obtained at the signal time periods; and reconstruct the image from the corrected detection signals obtained at the signal time periods.

Dynamic background correction in MPI

In Magnetic Particle Imaging (MPI) the reconstruction requires the knowledge of a so called system function. This function describes the relation between spatial position and frequency response. For reasonable resolutions and field of views the system function becomes quite large, resulting in large acquisition times for the system function and high memory demand during reconstruction. The present invention proposes to reduce the size of the system function matrix by making use of structural properties of the matrix. Such properties are, for instance, spatial symmetries reducing the number of columns and identical responses at different frequencies reducing the number of rows. In other embodiments the matrix can be transformed to a sparse representation using appropriate base functions.

Arrangement and method for detecting and/or locating a magnetic material in a region of action

The present invention relates to an apparatus () for influencing and/or detecting magnetic particles in a field of view (), wherein the field of view () comprises at least one sub field of interest covering at least a portion of an object of interest containing magnetic particles. The apparatus () applying the known principle of Magnetic Particle Imaging (MPI) comprises selection means for generating a magnetic selection field () having the known field pattern showing a field free point (FFP), drive means for changing the position in space of the FFP by means of a magnetic drive field, receiving means for acquiring detection signals depending on the magnetization of the magnetic particles within the field of view (), a control unit () for controlling a signal receiving unit () comprised in the receiving means for acquiring a set of high resolution detection signals and a set of low resolution detection signals, wherein the set of high resolution detection signals depends on the magnetization of at least one subfield of interest and the set of low resolution detection signals depends on the magnetization of at least one adjacent subfield being arranged adjacent to the at least one subfield of interest, and a reconstruction unit () for reconstructing a particle distribution quantity depending on the set of high resolution detection signals and the set of low resolution detection signals. The present invention further relates to a corresponding method as well as to a computer program.

Apparatus and method for influencing and/or detecting magnetic particles in a field of view

The present invention relates to an apparatus () for determining at least one electromagnetic quantity characterizing an electromagnetic property of an object, in particular a human body, wherein said object contains magnetic particles. The apparatus () applying the known principle of Magnetic Particle Imaging (MPI) comprises selection means for generating a magnetic selection field () having the known field pattern showing a field free point (FFP), drive means for changing the position in space of the FFP by means of a magnetic drive field, receiving means for acquiring detection signals depending on the magnetization of the magnetic particles within a field of view () and a reconstruction unit () for reconstructing a particle distribution quantity depending on the detection signals. The apparatus () further comprises a control unit () for controlling the receiving means for acquiring a first set of detection signals corresponding to a first drive field frequency and a second set of detection signals corresponding to a second drive field frequency, with both drive field frequencies differing from each other. The control unit () further controls the reconstruction unit () for reconstructing a first particle distribution quantity depending on the first set of detection signals and a second particle distribution quantity depending on the second set of detection signals. The apparatus () further comprises a determination unit () for determining the electromagnetic quantity depending on the first and second particle distribution quantity. The present invention further relates to a corresponding method as well as to a computer program.

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Hamburg, Germany

Jürgen Erwin Rahmer