# US 11,998,259 B2 · Device and method for detecting faults in a shielded instrument

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,998,259 B2
- Document ID: US11998259B2
- Status: Granted
- Kind: B2
- Application number: 17/685,156
- Filed: 2022-03-02
- Published: 2022-10-20
- Granted: 2024-06-04
- Earliest claimed: 2014-06-11
- Assignees: Encision, Inc.
- Applicants: Encision Inc.
- Inventors: David Newton
- Web page: https://patentgrep.com/patent/US11998259B2

## CPC

- A61B 18/1233: {with circuits for assuring patient safety}
- A61B 2018/00678: {upper}
- A61B 2018/00708: {switching the power on or off}
- A61B 2018/00827: {Current}
- A61B 2018/1226: {powered by a battery}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

A device and method for detecting faults in a shield of an electrosurgical instrument is described. The device has a relay configured to selectively interrupt power to the electrosurgical instrument, monitoring circuitry configured to monitor a shield in the electrosurgical instrument, control circuitry to control the relay, and a battery power source. The monitoring circuitry has an envelope detector and a detected average shield current detector. The monitoring circuitry is configured to compare a shield current peak value to a shield current peak threshold value, and to compare a detected average shield current value to a detected average shield current threshold value. The device is further configured to operatively couple an active electrode of an electrosurgical instrument and a return electrode to an electrosurgical generator.

## Claims

### Claim 1

A monitoring device for detecting insulation faults in an electrosurgical instrument, comprising:
a relay configured to interrupt power to the electrosurgical instrument;
control circuitry configured to control the relay;
monitoring circuitry configured to monitor electrical signals associated with a shield in the electrosurgical instrument and detect faults in the shield through a fault threshold; and
wherein the monitoring device is configured to operatively couple an electrode cable of the electrosurgical instrument and a return cable to a generator;
wherein the monitoring circuitry comprises:
a current to voltage converter configured to convert a return current of the shield into a voltage signal of the shield;
an envelope detector configured to detect a peak value of the voltage signal of the shield; and
a radio frequency (RF) parameter detector configured to detect an active to return voltage;
wherein a low active to return voltage increases sensitivity of the monitoring device and decreases the fault threshold and wherein a high active voltage decreases sensitivity of the monitoring device and increases the fault threshold.

### Claim 2 (depends on 1)

The monitoring device of claim 1, wherein the RF parameter detector is further configured to detect an average shield current.

### Claim 3 (depends on 1)

The monitoring device of claim 1, wherein the RF parameter detector is further configured to detect a real power in the shield.

### Claim 4 (depends on 1)

The monitoring device of claim 1, wherein the RF parameter detector is further configured to detect a root mean square (RMS) of a real part of a shield current.

### Claim 5 (depends on 1)

The monitoring device of claim 1, wherein the RF parameter detector is further configured to detect a RMS of a total current in the shield.

### Claim 6 (depends on 1)

The monitoring device of claim 1, wherein the RF parameter detector is further configured to detect a magnitude of an impedance or a capacitance between an active electrode and the shield, and a resistance between the active electrode and the shield.

### Claim 7 (depends on 1)

The monitoring device of claim 1, wherein the RF parameter detector is further configured with an OR function configured to detect a fault when the peak value or an RF parameter exceeds a predefined threshold value.

### Claim 8 (depends on 7)

The monitoring device of claim 7, wherein the monitoring device is configured to require the peak value or the RF parameter to exceed a predetermined threshold value for a predetermined length of time before detecting a fault.

### Claim 9 (depends on 1)

The monitoring device of claim 1, wherein the RF parameter detector is a full wave rectified average (FWRA) detector configured to generate a full wave rectified average value of the voltage signal of the shield.

### Claim 10 (depends on 1)

The monitoring device of claim 1, wherein the monitoring device further comprises a shield current return connector configured to operatively couple the return current of the shield to the generator.

### Claim 11

A system for detecting insulation faults within an electrosurgical instrument, comprising:
an electrosurgical generator;
the electrosurgical instrument having a shield electrically coupled to the electrosurgical generator; and
a monitoring device comprising:
monitoring circuitry configured to monitor electrical signals associated with the shield in the electrosurgical instrument and comprising a current to voltage converter configured to convert a return current of the shield into a voltage signal of the shield;
an envelope detector configured to detect a peak-to-peak value of the voltage signal of the shield;
control circuitry responsive to the monitoring circuitry, configured to control a relay;
a radio frequency (RF) parameter detector configured to detect a fault threshold of an active to return voltage; and
where the monitoring circuitry is configured to perform one or more of:
(a) increasing sensitivity of the electrosurgical instrument and decreasing the fault threshold when a low active to return voltage is detected by the RF parameter detector;
(b) decreasing sensitivity of the electrosurgical instrument and increasing the fault threshold when a high active voltage is detected by the RF parameter detector; and
(c) interrupting power to the electrosurgical instrument.

### Claim 12 (depends on 11)

The system of claim 11, wherein the RF parameter detector is further configured with an OR function configured to detect a fault when a peak value or an RF parameter exceeds a predefined threshold value.

### Claim 13 (depends on 12)

The system of claim 12, wherein the monitoring device is configured to require the peak value or the RF parameter to exceed a predetermined threshold value for a predetermined length of time before detecting a fault.

### Claim 14 (depends on 13)

The system of claim 13, further comprising a battery, wherein the monitoring circuitry, the control circuitry, and the battery are connected to a common circuit ground point.

### Claim 15 (depends on 13)

The system of claim 13, wherein the control circuitry comprises a warning device responsive to the monitoring circuitry.

### Claim 16 (depends on 11)

The system of claim 11, wherein the RF parameter detector is a full wave rectified average (FWRA) detector configured to generate a full wave rectified average value of the voltage signal of the shield.

### Claim 17

A method for detecting insulation faults in an electrosurgical instrument, comprising:
connecting a monitoring device for detecting instrument insulation faults to an electrosurgical generator, the electrosurgical generator configured to deliver power to the electrosurgical instrument;
coupling the monitoring device to a shielded electrosurgical instrument;
monitoring a set up signal of the shielded electrosurgical instrument;
monitoring a return current of the shielded electrosurgical instrument;
determining low and high threshold values of an active to return voltage of the monitoring device; and
adjusting a fault threshold and sensitivity of the monitoring device per the active to return voltage.

### Claim 18 (depends on 17)

The method of claim 17, wherein a low active to return voltage increases the sensitivity of the monitoring device and decreases the fault threshold, and a high active voltage decreases the sensitivity of the monitoring device and increases the fault threshold.

### Claim 19 (depends on 17)

The method of claim 17, further comprising:
determining whether a peak value or an RF parameter exceeds a predefined threshold value.

### Claim 20 (depends on 19)

The method of claim 19, further comprising:
detecting a fault when the peak value or the RF parameter exceeds the predefined threshold value for a predetermined length of time.