Medical gas insufflator with automatic gas flow control
First Claim
1. A method of operating a medical insufflator comprising:
- a flexible tube having a downstream end provided with a needle and an upstream end, the tube and needle forming an insufflation flow path for a neutral gas into a surgical cavity into which the needle is inserted,a supply of the neutral gas under pressure connected to the upstream end, anda flow-control valve along the flow path at the upstream end,the method comprising the steps of;
measuring an insufflation pressure at the upstream end of the insufflation path,continuously calculating intracavity pressure from the insufflation pressure by evaluating loss of pressure of the flow path,comparing the calculated inntracavity pressure and a preset value of this intracavity pressure,controlling the flow-control valve as a function of the result of the comparison with the above-mentioned preset value in order to continuously supply a flow the neutral gas that is minimally sufficient to compensate for leakage of gas from the surgical cavity and to maintain the intracavity pressure generally equal to the preset value; and
compensating for leaks from surgical cavity by evaluating the derivative with respect to time of the offset between the preset pressure value and the intracavity pressure.
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Accused Products
Abstract
A medical insufflator has a flexible tube having a downstream end provided with a needle and an upstream end, the tube and needle forming an insufflation flow path for a neutral gas into a surgical cavity into which the needle is inserted, a supply of the neutral gas under pressure connected to the upstream end, and a flow-control valve along the flow path at the upstream end. It is operated by measuring an insufflation pressure at the upstream end of the insufflation path, continuously calculating intracavity pressure from the insufflation pressure by evaluating loss of pressure of the flow path, comparing the calculated intracavity pressure and a preset value of this intracavity pressure, and controlling the flow-control valve as a function of the result of the comparison with the above-mentioned preset value in order to continuously supply a flow of the neutral gas that is minimally sufficient to compensate for leakage of gas from the surgical cavity and to maintain the intracavity pressure generally equal to the preset value.
101 Citations
8 Claims
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1. A method of operating a medical insufflator comprising:
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a flexible tube having a downstream end provided with a needle and an upstream end, the tube and needle forming an insufflation flow path for a neutral gas into a surgical cavity into which the needle is inserted, a supply of the neutral gas under pressure connected to the upstream end, and a flow-control valve along the flow path at the upstream end, the method comprising the steps of; measuring an insufflation pressure at the upstream end of the insufflation path, continuously calculating intracavity pressure from the insufflation pressure by evaluating loss of pressure of the flow path, comparing the calculated inntracavity pressure and a preset value of this intracavity pressure, controlling the flow-control valve as a function of the result of the comparison with the above-mentioned preset value in order to continuously supply a flow the neutral gas that is minimally sufficient to compensate for leakage of gas from the surgical cavity and to maintain the intracavity pressure generally equal to the preset value; and compensating for leaks from surgical cavity by evaluating the derivative with respect to time of the offset between the preset pressure value and the intracavity pressure. - View Dependent Claims (2, 3, 4)
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5. A method of operating a medical insufflator comprising:
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a flexible tube having a downstream end providing with need and an upstream end, the tube and needle forming an insufflation flow path for a neutral gas into a surgical cavity into which the needle is inserted, a supply of neutral gas under pressure connected to the upstream end, and a pneumatic control assembly comprised of the following in order from the gas supply to the downstream end; primary expansion means for reducing to a low accurate pressure the pressure of the gas to be insufflated at the output of the supply of gas, a filter, an input safety valve, a secondary expanding capillary creating laminar flow and to which is associated a differential pressure sensor that determines the instantaneous flow at the neutral gas, a proportional flow-control valve that is opened electrically in accordance with the instantaneous flow and the flow, an output safety valve, and a gas outlet associated with measuring means for the insufflation pressure used for calculating and controlling (the) an intracavity pressure, the method comprising the steps of; measuring an insufflation pressure at the upstream end of the insufflation path, continuously calculating intracavity pressure from the insufflation pressure by evaluating loss of pressure of the flow path, comparing the calculated intracavity pressure and a preset value of this intracavity pressure, controlling the flow-control valve as a function of the result of the comparison with the above-mentioned preset value in order to continuously supply a flow of the neutral gas that is minimally sufficient to compensate for leakage of the surgical cavity and to maintain the intracavity pressure generally equal to the preset value. - View Dependent Claims (6, 7, 8)
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Specification