Method and apparatus for detecting and treating vulnerable plaques
AssigneeMeridian Medical Systems, LLC
InventorKenneth L. Carr
Life of this patent
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Abstract
The present technique utilizes microwave radiometry to detect the presence of vulnerable plaques engrained in the wall of a blood vessel. In accordance with the technique, an intravascular catheter containing at least one microwave antenna is moved along the suspect vessel. The antenna, in combination with an external microwave detection and display unit, is able to detect and display thermal anomalies due to the difference in the thermal emissivity (brightness) of vulnerable plaques as compared to normal tissue even though the two may have a common temperature.
Claims19
A method of detecting vulnerable plaques engrained or embedded in otherwise normal tissue in a wall of a patient's blood vessel containing blood whose temperature corresponds to that of said normal tissue, said method comprising the steps of
- forming an intravascular catheter containing a first microwave antenna tuned to a first frequency enabling it to detect temperature at depth in said wall and produce a corresponding first frequency signal, and a second antenna designed to pick up thermal emissions from said blood to sense the temperature thereof and produce a corresponding reference signal;
- applying said signals by way of a diplexer separately to a differential radiometer to produce an output signal therefrom which reflects said temperature at depth relative to the blood temperature, and
- moving the catheter along said vessel so that at each point along the vessel said output signal indicates the presence or absence of vulnerable plaques in said vessel wall due to the higher emissivity thereof as compared to that of the normal tissue.
Apparatus for detecting vulnerable plaques engrained or imbedded in otherwise normal tissue in a wall of a patient's blood vessel containing blood whose temperature is substantially the same as that of said normal tissue, said apparatus comprising
- an intravascular catheter containing a microwave antenna tuned to a first frequency enabling it to detect temperature at depth in said wall and produce a corresponding first frequency signal;
- a radiometer having a signal input, a reference input and an output,
- a diplexer connecting the antenna to the signal input;
- a second antenna in the catheter for sensing the temperature of the blood and producing a corresponding reference signal, and
- means for applying the reference signal to the reference input, said catheter being movable along said vessel so that at each axial location along the vessel, said output signal indicates the presence or absence of vulnerable plaques due to the higher emissivity thereof as compared to that of the normal tissue.
A method of detecting vulnerable plaque ingrained or imbedded in otherwise normal tissue comprising a wall of a patient's blood vessel containing blood whose temperature is substantially the same as that of said normal tissue, said method comprising the steps of
- forming an intravascular catheter containing a first microwave antenna tuned to a first frequency enabling detection of the temperature at depth in said wall and a second microwave antenna tuned to a second frequency enabling the detection of the temperature of said blood;
- providing a first radiometer having an operating frequency range which includes said first frequency and with an input connected by way of a diplexer to the first antenna and which produces a first output signal representing said temperature at depth;
- providing a second radiometer having an operating frequency range which includes said second frequency and with an input connected by way of said diplexer to the second antenna and which produces a second output signal representing the temperature of said blood;
- producing a difference signal from said first and second output signals, and
- moving the catheter along said vessel so that at each axial location along the vessel, said difference signal indicates the presence or absence of vulnerable plaque in said vessel wall due to the higher emissivity of said plaque as compared to the normal tissue.
Dependencies are inferred from the claim text.