Catheter depth, position and orientation location system
First Claim
1. For externally locating a sensor in tissue, a system comprising:
- a) an external probe including at least first and second output coils having respective non-parallel first and second output-coil axes;
b) an output coil-driver circuit that alternately so energizes the first and second output coils as to generate first and second time-varying magnetic fields that penetrate the tissue;
c) a sensor coil that has a sensor-coil axis and develops first and second sensor signals in response to the first and second time-varying magnetic fields, respectively; and
d) a distance determinator that determines from the first and second sensor signals, independently of the relative angles between the projection of the sensor-coil axis and the projections of the first and second output-coil axes into a plane parallel to the first and second output-coil axes, the distance between the sensor coil and the output coils and generates a distance signal representative of the distance thus determined.
6 Assignments
0 Petitions
Accused Products
Abstract
A system for externally locating a sensor in tissue, comprising an external probe including at least first and second electromagnetic output coils with non-parallel longitudinal axes; and output coil driver for alternately energizing the first and second output coils, for generating a time-varying magnetic field which penetrates the patient'"'"'s skin; a sensor coil, having a longitudinal axis, for developing an induced electrical voltage in response to the time-varying magnetic field; a distance determinator, responsive to the induced voltage from the sensor coil, for determining from the induced voltage, the distance between the output coils and the sensor coil, independently of the relative angle, in a horizontal plane, between the sensor coil longitudinal axis, and the longitudinal axes of the output coils; and a direction determinator for determining and displaying the direction, in the horizontal plane, in which the sensor coil longitudinal axis is pointing.
572 Citations
40 Claims
-
1. For externally locating a sensor in tissue, a system comprising:
-
a) an external probe including at least first and second output coils having respective non-parallel first and second output-coil axes; b) an output coil-driver circuit that alternately so energizes the first and second output coils as to generate first and second time-varying magnetic fields that penetrate the tissue; c) a sensor coil that has a sensor-coil axis and develops first and second sensor signals in response to the first and second time-varying magnetic fields, respectively; and d) a distance determinator that determines from the first and second sensor signals, independently of the relative angles between the projection of the sensor-coil axis and the projections of the first and second output-coil axes into a plane parallel to the first and second output-coil axes, the distance between the sensor coil and the output coils and generates a distance signal representative of the distance thus determined. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
-
-
33. For externally locating a sensor in tissue, a system comprising:
-
a) an external probe including an output coil; b) an output coil-driver circuit that so energizes the output coil as to generate a time-varying magnetic field that penetrates the tissue; c) a sensor coil that has a sensor-coil axis and develops a sensor signal in response to the time-varying magnetic field; and d) a sensor-coil-position determinator that establishes a first threshold equal to a predetermined fraction of a peak value of the sensor signal'"'"'s magnitude, makes a determination from the sensor signal of whether the output coil'"'"'s axis is proximate a plane normal to the sensor-coil axis at the sensor coil'"'"'s midpoint by determining whether a relative null has occurred in the sensor signal, and generates a proximity signal indicative of that determination, the proximity signal indicating that the relative null has occurred only if the sensor signal'"'"'s magnitude falls below the first threshold. - View Dependent Claims (34, 35, 36, 37, 38)
-
-
39. For externally locating a sensor in tissue, a system comprising:
-
a) an external probe including at least first and second output coils having respective non-parallel first and second output-coil axes; b) an output coil-driver circuit that alternately so energizes the first and second output coils as to generate first and second time-varying magnetic fields that penetrate the tissue; c) a sensor coil that has a sensor-coil axis and develops first and second sensor signals in response to the first and second time-varying magnetic fields, respectively; d) an analog-to-digital converter that responds to the sensor signals by generating digital signals representative thereof; e) a microprocessor that controls the output of the coil-driver circuit, that determines from the digital signals (1) the relative angle between the projection of the sensor-coil axis and that of at least one of the first and second output-coil axes into a plane parallel to the first and second output coil axes and, (2) independently of the relative angles between the projection of the sensor-coil axis and the projections of the first and second output-coil axes into a plane parallel to the first and second output-coil axes, the distance between the sensor coil and the output coils, and that generates angle and distance signals respectively indicative of the angle and distance thereby determined; f) a direction indicator that receives the angle signal and generates a humanly perceptible indication of the angle represented thereby; and g) a distance indicator that receives the distance signal and generates a humanly perceptible indication of the distance represented thereby. - View Dependent Claims (40)
-
Specification