Gas concentration measurement in gas sealed trocars

Patent metadata

Field	Value
Publication number	US-2023077000-A1
Application number	US-202117467790-A
Country	US
Kind code	A1
Filing date	Sep 7, 2021
Priority date	Sep 7, 2021
Publication date	Mar 9, 2023
Grant date	—

Abstract

A system for monitoring gas composition in a surgical cavity during an endoscopic surgical procedure includes an gas recirculation system including a main gas flow circuit for fluid communication with a surgical cavity. The system includes a sensor for monitoring a gas species in a gas flow from a surgical cavity of a patient. The sensor is positioned in a channel branching off from the main gas flow circuit coming from the surgical cavity.

First claim

What is claimed is:

1 . A system for monitoring gas composition in a surgical cavity during an endoscopic surgical procedure, comprising:
a gas recirculation system including a main gas flow circuit for fluid communication between a surgical cavity and the gas recirculation system; a flow channel branching off from the main gas flow; and a sensor operatively associated with the flow channel for monitoring a gas species in the gas flow through the main gas flow circuit.

2 . The system as recited in claim 1 , wherein the channel branching off from the main gas flow circuit is a dead-end channel in the gas recirculation system.

3 . The system as recited in claim 1 , wherein the main gas flow circuit has a cross-sectional flow area with a main diameter, and wherein the sensor is spaced apart from the main gas flow circuit by a distance along the channel of ten or more main diameters distance so the sensor can detect the gas species reaching the sensor by diffusion through the channel from the main gas flow circuit.

4 . The system as recited in claim 1 , further comprising a compressor operatively connected to the gas recirculation system in the main gas flow circuit to move the flow of gas to and from the surgical cavity, wherein the channel connects to the main gas flow circuit at a position in the main gas flow circuit downstream from the compressor.

5 . The system as recited in claim 4 , wherein the main gas flow circuit includes an upstream portion for returning gas from the surgical cavity to the gas recirculation system, and a downstream portion for issuing gas to the surgical cavity, wherein the compressor separates between the upstream and downstream portions, and wherein the channel connects to the downstream portion.

6 . The system as recited in claim 5 , further comprising a gas sealed access port connected to the upstream portion and to the downstream portion for connecting the gas recirculation system to the surgical cavity.

7 . The system as recited in claim 6 , wherein the gas sealed access port, the upstream portion, the downstream portion, and the compressor are configured to form a continuous gas recirculation circuit with the gas sealed access port positioned in a surgical cavity.

8 . The system as recited in claim 1 , further comprising: a controller operatively connected to the sensor for determining if the gas species monitored in the gas flow from the surgical cavity is within a respective desired range and taking corrective action if the gas species is outside the respective desired range.

9 . The system as recited in claim 8 , wherein the controller is operatively connected to a circuit of the sensor to monitor changes in electrical resistance of the sensor to determine concentration of the gas species to which the senor is exposed.

10 . The system as recited in claim 8 , further comprising a user interface operatively connected to the controller, wherein the controller is configured to issue an alert to a user through the user interface upon detection of the gas species at a predetermined threshold.

11 . The system as recited in claim 8 , wherein the controller includes a memory, wherein the controller includes machine readable instructions configured to cause the controller to write a history of gas concentration detected by the sensor for a 1 to 60 second interval for recall upon gas levels in excess of a predetermined threshold.

12 . The system as recited in claim 1 , wherein the sensor includes a metal oxide film and heater, configured to detect hydrogen presence in a concentration range of 100 ppm (parts per million), to 10 ppt (parts per thousand), inclusive of endpoints.

13 . The system as recited in claim 12 , wherein the sensor is configured so a presence of hydrogen at 10 ppt yields a drop in electrical resistance across the sensor of at or below 10 kilo-Ohms.

14 . A method of detecting perforated bowel during a surgical procedure, the method comprising:
detecting presence of a gas species indicative of a perforated bowel with a sensor, wherein the gas species reaches the sensor by diffusion from a main gas flow circuit of an gas recirculation in fluid communication with a surgical cavity; and outputting an alert upon detection of the gas species at a threshold indicative of a perforated bowel.

15 . The method as recited in claim 14 , wherein the sensor is located in a channel branching off from the main gas flow circuit, wherein the channel is a dead-end channel, wherein detecting includes detecting the gas species without bulk gas flow through the dead-end channel.

16 . The method as recited in claim 15 , wherein the main gas flow circuit has a cross-sectional flow area with a main diameter, and wherein the sensor is spaced apart from the main gas flow circuit by a distance along the dead-end channel of ten or more main diameters.

17 . The method as recited in claim 15 , wherein detecting includes sampling gas from the main gas flow circuit with the sensor, wherein sampling gas includes sampling the gas from a position in the main gas flow circuit downstream from a compressor operatively connected to the gas recirculation system in the main gas flow circuit to move the flow of gas to and from the surgical cavity.

18 . The method as recited in claim 17 , wherein moving the flow of gas to and from the surgical cavity includes flowing gas to and from the surgical cavity through a gas sealed access port connecting between the gas recirculation system and the surgical cavity, wherein the gas sealed access port and gas recirculation system form a sealed recirculation circuit with the gas sealed access port positioned in a surgical cavity.

19 . The method as recited in claim 14 , wherein a controller operatively connected to the sensor determining if the gas species monitored in the gas flow from the surgical cavity is within a respective desired range and to initiate output to an output device to alert a user to take corrective action if the gas species is outside the respective desired range.

20 . The method as recited in claim 19 , wherein the controller is operatively connected to a circuit of the sensor to monitor changes in electrical resistance of the sensor to determine concentration of the gas species to which the senor is exposed.

21 . The method as recited in claim 14 , further comprising outputting a history of gas concentration detected by the sensor for a 1 to 60 second interval for recall upon gas levels of the gas species in excess of a predetermined threshold.

22 . The method as recited in claim 14 , wherein the sensor includes a metal oxide film and heater, and wherein detecting the gas species includes using the metal oxide film to detect hydrogen presence in a concentration range of 100 ppm (parts per million), to 10 ppt (parts per thousand), inclusive of endpoints.

Assignees

• Conmed Corp

Inventors

• Koltz Jr Michael
• Hawkins Luke Samuel
• Tegan Gary

Classifications

• A61M16/085

  Gas sampling · CPC title

• A61B2562/02

  Details of sensors specially adapted for in-vivo measurements · CPC title

• A61B10/00

  Instruments for taking body samples for diagnostic purposes (for taking samples of blood A61B5/15); Other methods or instruments for diagnosis, e.g. for vaccination diagnosis, sex determination or ovulation-period determination; Throat striking implements · CPC title

• A61B2218/008

  for smoke evacuation · CPC title

• A61B2010/0083

  for taking gas samples · CPC title