Radiometric tissue contact and tissue type detection

Inventors

Panescu, Dorin • Johnson, Jessi E. • Koblish, Josef Vincent • McCarthy, John F.

Assignees

Epix Therapeutics Inc

Abstract

Radiometric systems may comprise a radiometer, an antenna and a processor communicatively coupled together. The processor may provide a contact-focused output based on filtering or other processing of a raw radiometric output signal. The contact-focused output may facilitate determination of whether contact has been achieved and/or assessment of contact. A miniaturized reflectometer may be configured to determine an amount of reflected power from the antenna. The processor may be configured to determine a reflection coefficient of the reflected power determined by the reflectometer and to identify tissue type based on the reflection coefficient. Systems and methods for facilitating deeper temperature measurements of a radiometer are described.

Core Innovation

The invention facilitates determination of quality of contact between an energy delivery device and at least one area of tissue prior to and during energy delivery. A radiometer provides a signal from which processor-extracted variability information is computed as a variability index based on a moving average of the radiometer signal and a set of raw output signal data. The processor determines a level of tissue contact based, at least in part, upon the variability information and generates an output indicative of the level of tissue contact for contemporaneous display together with the variability information on a user interface.

The system further includes a reflectometer that determines a reflection coefficient in the at least one area of tissue, and the reflection coefficient is indicative of the level of tissue contact between a distal tip of the energy delivery device and the tissue. The system determines whether the at least one area of tissue is one of an area of intact tissue or an area of ablated tissue based on a change in the reflection coefficient. In another independent formulation, the processor receives a first output signal from a radiometer and a second output signal from a reflectometer, extracts variability information including a variability index, and determines the level of tissue contact based on the extracted variability information and the measured reflection coefficient.

The radiometer is configured to continuously switch between the antenna and a reference load to correct for variations in local temperature, with switching controlled by at least one clock. The system is further configured to detect and reduce at least one variability reading caused by one of a respiratory artifact and a cardiac artifact. In a method embodiment, variability information derived from the radiometer signal is displayed while tissue contact level determination is performed using the variability information together with the measured reflection coefficient, and intact versus ablated tissue is determined using change in the reflection coefficient.

Claims Coverage

The document includes three independent claims that cover a system and a method for determining and displaying tissue-contact quality by combining radiometer-derived variability information with reflectometer-derived reflection coefficient change for intact versus ablated tissue discrimination, while correcting radiometer readings for local temperature variations and reducing variability readings caused by respiratory and cardiac artifacts.

Across the independent claims, the core inventive coverage is the joint use of radiometer signal variability processing and reflectometer reflection coefficient change, combined with radiometer antenna/reference switching to correct local temperature variations and detection or reduction of variability readings caused by respiratory and cardiac artifacts, with contemporaneous display of variability information and tissue-contact level on a user interface or display.

Stated Advantages

Documented Applications