A medical gas insufflation device comprising at least a gas outlet circuit, a connector for connecting a pressurized vessel in which the gas is packaged, an expander placed between the connector and the gas outlet circuit, a high-pressure sensor placed between the connector and the expander, a flow meter placed at the outlet from the expander, and a microprocessor connected at least to the sensor to receive signals representative of the pressure observed at the connector and to the flow meter to receive signals representative of the flow rate at the outlet from the expander, wherein the microprocessor includes evaluation means for evaluating the remaining volume of gas after expansion as a function of the signals received from the sensor and the flow meter during a gas expansion operation.