Locating features in the heart using radio frequency imaging

Abstract

Diagnostic apparatus ( 20 ) includes an antenna 32 , which is configured to direct radio frequency (RF) electromagnetic waves into a living body and to generate signals responsively to the waves that are scattered from within the body. Processing circuitry ( 36 ) is configured to process the signals so as to locate a feature in a blood vessel in the body.

1 - 58 . (canceled) 
     
     
         59 . A radio-frequency (RF) monitoring and/or diagnostic apparatus, comprising:
 a planar antenna configured to direct RF electromagnetic waves into the body of a patient and to generate signals responsively to the waves that are scattered from within the body, wherein a first surface of the antenna comprises a printed circuit board; and   processing circuitry configured to process the signals so as to determine a feature in the body responsively to a difference in a dielectric constant of the feature relative to surrounding tissue;   wherein, the antenna is configured to be positioned in close proximity to a surface of the body of the patient.   
     
     
         60 . The apparatus of  claim 59 , wherein close proximity to a surface of the body of the patient comprises the antenna being in contact with the skin of the patient. 
     
     
         61 . The apparatus of  claim 59 , further comprising a first material configured for arrangement between the body of the patient and the antenna. 
     
     
         62 . The apparatus of  claim 61 , wherein the first material comprises at least one of an adhesive, a gel, and apparel. 
     
     
         63 . The apparatus of  claim 59 , wherein determining the feature in the body comprises identifying and tracking a movement of the feature in the body. 
     
     
         64 . The apparatus of  claim 63 , wherein tracking the movement of the feature in the body includes imaging the feature and estimating a trajectory of the feature based on analysis of the image of the feature. 
     
     
         65 . The apparatus of  claim 59 , wherein the feature comprises a tissue in the body. 
     
     
         66 . The apparatus of  claim 59 , wherein the RF electromagnetic waves are in a frequency range of from about 400 MHz to about 4 GHz. 
     
     
         67 . A radio-frequency (RF) monitoring and/or diagnostic apparatus comprising:
 a planar antenna configured to direct RF electromagnetic waves into the body of a patient and to generate signals responsively to the waves that are scattered from within the body, wherein a first surface of the antenna comprises a printed circuit board;   processing circuitry configured to process the signals so as to determine a feature in the body responsively to a difference in a dielectric constant of the feature relative to surrounding tissue; and   a first material configured for arrangement between the antenna and the skin of the patient during use.   
     
     
         68 . The apparatus of  claim 67 , wherein the first material comprises at least one of an adhesive, a gel and apparel. 
     
     
         69 . The apparatus of  claim 67 , wherein the first material is configured so as to substantially affix the antenna in close proximity to the skin of the body. 
     
     
         70 . The apparatus of  claim 67 , further comprising a cavity proximate the antenna and configured to at least increase overall gain of the signals. 
     
     
         71 . The apparatus of  claim 70 , wherein the cavity comprises a waveguide. 
     
     
         72 . The apparatus of  claim 71 , wherein the waveguide includes dimensions configured such that a cutoff frequency of the lowest propagating mode in the waveguide exceeds an upper band frequency limit of the antenna. 
     
     
         73 . The apparatus of  claim 67 , further comprising a case for sealing the planar antenna against the first material and/or a liquid. 
     
     
         74 . The apparatus of  claim 67 , wherein the RF electromagnetic waves are in a frequency range of from about 400 MHz to about 4 GHz. 
     
     
         75 . A radio-frequency (RF) monitoring and/or diagnostic apparatus comprising:
 a planar antenna configured to direct RF electromagnetic waves into the body of a patient and to generate signals responsively to the waves that are scattered from within the body, wherein a first surface of the antenna comprises a printed circuit board;   processing circuitry configured to process the signals so as to determine a feature in the body responsively to a difference in a dielectric constant of the feature relative to surrounding tissue; and   a wearable element comprising at least one of the planar antenna and the processing circuitry, the wearable element configured to abut skin of the body of the patient.   
     
     
         76 . The apparatus of  claim 75 , wherein the planar antenna is a multi-element antenna, and further comprising a switching matrix configured to switch elements of the multi-element antenna between a transmitter and a receiver. 
     
     
         77 . The apparatus of  claim 75 , wherein determining a feature in the body comprises identifying and tracking a movement of the feature in the body. 
     
     
         78 . The apparatus of  claim 75 , wherein tracking the movement of the feature in the body includes imaging the feature and estimating a trajectory of the feature based on analysis of the image of the feature. 
     
     
         79 . The apparatus of  claim 75 , wherein the planar antenna includes a plurality of antenna elements, the plurality of antenna elements positioned about the body of the patient such that a first antenna element receives reflected waves and a second antenna element receives the scattered waves. 
     
     
         80 . The apparatus of  claim 79 , further comprising one or more position sensors configured to determine respective positions of the plurality of antenna elements. 
     
     
         81 . The apparatus of  claim 75 , wherein the RF electromagnetic waves are in a frequency range of from about 400 MHz to about 4 GHz.