CONTACT SENSING SYSTEMS AND METHODS
4 Assignments
0 Petitions
Accused Products
Abstract
According to some embodiments, a medical instrument comprises an elongate body having a proximal end and a distal end and a pair of electrodes or electrode portions (for example, a split-tip electrode assembly). Systems and methods are described herein that perform contact sensing and/or ablation confirmation based on electrical measurements obtained while energy of different frequencies are applied to the pair of electrodes or electrode portions. The contact sensing systems and methods may calibrate network parameter measurements to compensate for a hardware unit in a network parameter measurement circuit or to account for differences in cables, instrumentation or hardware used.
13 Citations
40 Claims
-
1-20. -20. (canceled)
-
21. A system for determining whether a medical instrument is in contact with tissue based, at least in part, on impedance measurements, the system comprising:
-
a signal source configured to deliver signals having different frequencies to a pair of electrodes of a medical instrument; and a processing device configured to; process a resulting waveform that formulates across a pair of electrodes to obtain impedance measurements at a first frequency and a second frequency; determine a ratio between the magnitude of the impedance at the second frequency and the first frequency; if the determined ratio is below a predetermined threshold indicative of contact, generate a first output indicative of contact; and if the determined ratio is above the predetermined threshold, generate a second output indicative of no contact. - View Dependent Claims (22, 23, 24, 25, 26)
-
-
27. A method of determining whether a medical instrument is in contact with tissue based, at least in part, on impedance measurements, the method comprising:
-
applying signals having a first frequency and a second frequency to a pair of electrodes of medical instrument; processing a resulting waveform to obtain impedance measurements at the first frequency and the second frequency; determining a ratio between the magnitude of the impedance at the second frequency and the first frequency; if the determined ratio is below a predetermined threshold indicative of contact, generating a first output indicative of contact; and if the determined ratio is above the predetermined threshold, generating a second output indicative of no contact. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
-
Specification