US 5,498,261 A · Thermal angioplasty system

Abstract

A system for thermal angioplasty provides electrical power to a heating coil located inside a dilatation balloon, receives a signal from a sensor at the coil indicating its temperature and also receives signals from balloon sensors indicating the temperature at their respective positions. An isolation transformer is used to provide RF power and the sensor signals are optically coupled to provide increased electrical isolation for the patient. The heating coil temperature sensor signal is compared to high and low temperature limits and if either is exceeded, a fault signal is generated. The sensor signals from the balloon are compared to predetermined high temperature limits and if exceeded, fault signals are generated. The current drawn from the battery is compared to a predetermined current level and if exceeded, a fault signal is also generated. Upon generation of any of the fault signals, the electrical power to the heating coil is interrupted by fault detection circuitry. An RF ON reset switch is provided to prevent the inadvertent application of RF power to the heating coil. Materials used in the connectors and in the RF generator for connections to the catheter electrical leads are compatible with those leads to avoid a thermocouple effect.

Claims18

Dependent claims

A power generator for providing electrical power to a heating element of a catheter, the heating element having a temperature, the power generator comprising:

a temperature sensor for providing a temperature signal representative of the temperature at the heating element;
comparator means for comparing the temperature signal to signals representative of a predetermined temperature range and for providing a fault signal when the temperature signal indicates a temperature outside the range;
power source means for providing power to the heating element and for interrupting the power to the heating element in response to the fault signal;
alarm generator means for providing an alarm in response to the fault signal;
first isolation means for providing a first ground in the power generator for electrically interconnecting components of the power generator and for isolating the first ground from earth ground;
and
second isolation means for isolating the temperature signal from both the first ground and earth ground.

4 more elements

A power generator for providing power to a heating element of a catheter which has a dilatation balloon, the heating element having a temperature, the power generator comprising:

a first temperature sensor for providing a first sensor signal representative of the temperature at the heating element;
a second temperature sensor for providing a second sensor signal representative of the temperature at the balloon;
first comparator means for comparing the first sensor signal to a first threshold signal representative of a first predetermined fault temperature and for providing a first fault signal when the first sensor signal indicates a temperature which is less than the first fault temperature;
second comparator means for comparing the second sensor signal to a second threshold signal representative of a second predetermined fault temperature and for providing a second fault signal when the second sensor signal indicates a temperature which exceeds the second fault temperature;
a manually resettable power source means for providing power to the heating element and for interrupting power to the heating element in response to the first or second fault signal until after a manual reset of the power source means has occurred;
and
an alarm generator means for providing an alarm in response to the first or second fault signal.

4 more elements

A power generator for providing power to a heating element of a catheter which has a dilatation balloon, the heating element having a temperature, the power generator comprising:

a first temperature sensor for providing a first sensor signal representative of the temperature at the heating element;
a second temperature sensor for providing a second sensor signal representative of the temperature at the balloon;
first comparator means for comparing the first sensor signal to a first threshold signal representative of a first predetermined fault temperature and for providing a first fault signal when the first sensor signal indicates a temperature which is lower than the first fault temperature;
second comparator means for comparing the second sensor signal to a second threshold signal representative of a second predetermined fault temperature and for providing a second fault signal when the second sensor signal indicates a temperature which exceeds the second fault temperature;
power source means for providing power to the heating element and for interrupting power to the heating element in response to the first or second fault signal;
an alarm generator means for providing an alarm in response to the first or second fault signal;
first isolation means for providing a first ground in the power generator for electrically interconnecting components of the power generator and for isolating the first ground from earth ground;
and
second isolation means for isolating the power provided to the heating element from both the first ground and earth ground and for isolating the signal received from the first and second sensors from both the first ground and earth ground.

6 more elements

A power generator for providing electrical power to a heating element of a catheter which includes a dilatation balloon, the heating element having a temperature, the power generator comprising:

a first temperature sensor for providing a first sensor signal representative of the temperature at the heating element;
a second temperature sensor for providing a second sensor signal representative of the temperature at the balloon;
first comparator means for comparing the first sensor signal to a first threshold signal representative of a first predetermined low fault temperature and for providing a first fault signal when the first sensor signal indicates a temperature which is lower than the first fault temperature;
second comparator means for comparing the first sensor signal to a second threshold signal representative of a predetermined high fault temperature and for providing a second fault signal when the first sensor signal indicates a temperature higher than said second fault temperature;
third comparator means for comparing the second sensor signal to a third threshold signal representative of a third predetermined fault temperature and for providing a third fault signal when the second sensor signal indicates a temperature greater than the third fault temperature;
power source means for providing power to the heating element and for automatically interrupting power to the heating element in response to the first, second or third fault signal;
first isolation means for providing a first ground in the power generator and for isolating the first ground from earth ground;
second isolation means for isolating the signal from the first and second sensors from both the first ground and earth ground;
the second isolation means includes an optical coupler which converts the signals from the first and second sensors into optical signals for provision to the first, second, and third comparator means;
and
an alarm generator means for providing an alarm in response to the first, second or third fault signal.

8 more elements

Dependencies are inferred from the claim text.

Thermal angioplasty system

Life of this patent

Thermal angioplasty system

Life of this patent

Abstract

Claims18