Real-time graphic display of heat lesioning parameters in a clinical lesion generator system

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT In FIG.
1 is shown a lesion generator or power source 1, which is typical of existing systems.
It has a power control knob 2 which enables the operator to raise the power which is delivered through the output jack 7 through cable 8 to an electrode 9 which is inserted in the body of the human patient 6 The electrode has an exposed tip 10 through which, radiofrequency, microwave or other energy sources emanate to heat the tissue near tip 10 In addition, for electromagnetic sources there typically is a reference or indifferent output jack 11 which connects through reference cable 12 to a reference area electrode 14 as a return source of current.
Meter 3 display impedance while; Meters 4 display power, voltage, or current, and meter 5 displays the temperature of the tissue near tip 10.
The catheter electrode, as shown in FIG.
1 , may have a thermosensor inside of tip 10 so as to monitor the heating process of the tissue surrounding the electrode.
The lesion generator 1 is connected through cable 30 to a dynamic graphics monitor 15, screen.
This monitor is distinguished from a simple chart recorder, which has been implemented previously on lesion generator systems.
FIG.
2 shows more of the detail of the monitor 15.
Shown on the graphics monitor is a time display of two important lesion parameters: impedance and temperature.
The display monitor 20 may or may not be integrated with the lesion generator system 1 in a compact, unified cabinet Graph 21 shows the temperature curve versus time.
Before lesioning begins, this curve remains at approximately 37.
degree.
, which is body temperature.
A dashed line 40 on the screen a representation of that important 37.
degree.
benchmark temperature.
Also indicated on the screen is the 100.
degree.
C.
line, the boiling temperature of body fluids, indicated by a horizontal, dashed line 26.
When the lesion begins at the point 41, then the temperature will begin to rise In the case of cardiac ablation, this rise could be modulated by variations, as shown by the wavy portion of the dashed temperature line 24 Such variations could arise from cardiac pulsation of blood past the tip 10 or from movement of the catheter tip 10 in the heart itself Such movement could change the position of the tip 10 from regions of blood flow, to being against tissue wall, or perhaps even in or fully surrounded by the tissue wall itself