Miniature resonating marker assembly

A miniature resonating marker assembly having a geometric center, comprising:

• a core having an elongated central portion, a first cap having a first thickness, and a second cap having a second thickness, wherein the first thickness is different than the second thickness;
• a wire coil disposed around the central portion of the core between the first and second caps;
• and
• a capacitor connected to the wire coil operative to form a signal element that generates a magnetic field with a selected resonant frequency in response to a specific stimulus, the first cap being movable relative to the coil and capacitor for tuning the marker assembly to a selected resonant frequency;
• the magnetic field having a magnetic center along a first axis coincident with the geometric center of the resonating marker assembly.

A resonating marker assembly having a geometric center, comprising:

• a ferromagnetic core having an elongated central portion and first and second ferromagnetic endcaps attached to the central portion, the core being substantially symmetrical about a longitudinal axis of the core, and being asymmetrical about a lateral axis of the core;
• a wire coil disposed around the central portion of the ferromagnetic core intermediate the first and second endcaps;
• and
• a capacitor connected to the wire coil forming a signal element that generates a magnetic field with a selected resonant frequency in response to a specific stimulus, the magnetic field having a magnetic center along a first axis coincident with the geometric center of the resonating marker assembly.

A resonating marker assembly having a geometric center, comprising:

• a core having an elongated central portion and first and second endcaps connected to the central portion;
• a wire coil disposed around the central portion of core intermediate the first and second endcaps;
• and
• a capacitor connected to the wire coil to form a tuned signal element that generates a magnetic field with a selected resonant frequency in response to a specific stimulus, the first endcap being movable relative to the coil and capacitor for tuning the marker assembly to a selected resonant frequency, the magnetic field having a magnetic center along a first axis coincident with the geometric center of the resonating marker assembly.

A resonating marker assembly having a geometric center, comprising:

• a sleeve;
• a core having a central portion extending through the sleeve and a pair of endcaps connected to the central portion, the sleeve being between the endcaps, and the core being axially movable relative to the sleeve;
• a wire coil disposed around the sleeve;
• and
• a capacitor connected to the wire coil proximate to the core to form a signal element that generates a magnetic field with a selected resonant frequency in response to a specific stimulus, the core being axially movable relative to the sleeve and the coil for tuning the marker assembly to a selected resonant frequency, the magnetic field having a magnetic center along a first axis coincident with the geometric center of the resonating marker assembly.

A resonating marker assembly having a geometric center, comprising:

• a ferromagnetic core having a first end and a second end;
• a wire coil disposed around the ferromagnetic core;
• a capacitor positioned at the first end of the core and operatively connected to the wire coil to form a signal element that generates a magnetic field with a selected resonant frequency in response to a specific stimulus, the magnetic field having a magnetic center along a first axis coincident with the geometric center of the resonating marker assembly;
• and
• an axially adjustable segment at the second end of the core that projects outwardly with respect to the longitudinal axis of the core.

A resonating marker assembly having a geometric center, comprising:

• a core having a central portion intermediate to a pair of enlarged endcaps, the central portion having a first magnetic permeability and the enlarged endcaps having a second magnetic permeability different than the first magnetic permeability;
• a wire coil disposed around the core intermediate to the endcaps;
• a capacitor operatively connected to the wire coil to form a signal element that generates a magnetic field with a selected resonant frequency in response to a specific stimulus, the magnetic field having a magnetic center along a first axis coincident with the geometric center of the resonating marker assembly;
• and
• an inert encapsulation member encapsulating the core, the wire coil, and the capacitor forming an activatable unit implantable in a patient through an introducer needle.

A resonating marker assembly, comprising;

• a capacitor having an aperture therethrough;
• an elongated ferromagnetic core extending through the aperture in the capacitor;
• a wire coil connected to the capacitor, the wire coil having a first portion disposed around the core adjacent to one side of the capacitor, and a second portion disposed around the core adjacent to another side of the capacitor;
• and
• an inert encapsulation member encapsulating the capacitor, the core, and the coil.