A uterine ablation device, comprising: a shaft adapted to be inserted into a uterus of a patient, the shaft including an outflow lumen and an inflow lumen; a gas/fluid source configured to deliver gas or fluid through the inflow lumen of the shaft into the uterus; an outflow valve configured to seal the outflow lumen of the shaft, the outflow valve being a balloon valve; a flow meter disposed in or near the outflow lumen and configured to measure a flow rate of gas or fluid in the outflow lumen; and an electronic controller operatively coupled to the gas/fluid source, the outflow valve, and the flow meter, the electronic controller being configured to perform the following actions: (i) to cause the gas/fluid source to deliver gas or fluid through the inflow lumen of the shaft into the uterus to achieve uterine cavity distension and enable conduction of a uterine integrity test; (ii) during a transition from the end of the uterine integrity test to the start of a uterine patency test, whilst the uterine cavity is still distended as a result of action (i), to only partially open the outflow valve to remove gas or fluid from the uterus through the outflow lumen of the uterine ablation device yet temporarily maintain the uterine cavity distension achieved during the uterine integrity test; (iii) to cause the flow meter to measure the flow rate of gas or fluid in the outflow lumen while the outflow valve is only partially open during action (ii); and (iv) to conduct the patency test by comparing to a threshold value the flow rate of gas or fluid measured by the flow meter in action (iii) and determining that the uterine ablation device is not clogged or embedded in tissue if the flow rate of gas or fluid measured by the flow meter is above the threshold value; wherein the partial opening of the outflow valve comprises a pulsed opening of the outflow valve at various duty cycles. a shaft adapted to be inserted into a uterus of a patient, the shaft including an outflow lumen and an inflow lumen; a gas/fluid source configured to deliver gas or fluid through the inflow lumen of the shaft into the uterus; an outflow valve configured to seal the outflow lumen of the shaft, the outflow valve being a balloon valve; a flow meter disposed in or near the outflow lumen and configured to measure a flow rate of gas or fluid in the outflow lumen; and an electronic controller operatively coupled to the gas/fluid source, the outflow valve, and the flow meter, the electronic controller being configured to perform the following actions: (i) to cause the gas/fluid source to deliver gas or fluid through the inflow lumen of the shaft into the uterus to achieve uterine cavity distension and enable conduction of a uterine integrity test; (ii) during a transition from the end of the uterine integrity test to the start of a uterine patency test, whilst the uterine cavity is still distended as a result of action (i), to only partially open the outflow valve to remove gas or fluid from the uterus through the outflow lumen of the uterine ablation device yet temporarily maintain the uterine cavity distension achieved during the uterine integrity test; (iii) to cause the flow meter to measure the flow rate of gas or fluid in the outflow lumen while the outflow valve is only partially open during action (ii); and (iv) to conduct the patency test by comparing to a threshold value the flow rate of gas or fluid measured by the flow meter in action (iii) and determining that the uterine ablation device is not clogged or embedded in tissue if the flow rate of gas or fluid measured by the flow meter is above the threshold value; wherein the partial opening of the outflow valve comprises a pulsed opening of the outflow valve at various duty cycles. (i) to cause the gas/fluid source to deliver gas or fluid through the inflow lumen of the shaft into the uterus to achieve uterine cavity distension and enable conduction of a uterine integrity test; (ii) during a transition from the end of the uterine integrity test to the start of a uterine patency test, whilst the uterine cavity is still distended as a result of action (i), to only partially open the outflow valve to remove gas or fluid from the uterus through the outflow lumen of the uterine ablation device yet temporarily maintain the uterine cavity distension achieved during the uterine integrity test; (iii) to cause the flow meter to measure the flow rate of gas or fluid in the outflow lumen while the outflow valve is only partially open during action (ii); and (iv) to conduct the patency test by comparing to a threshold value the flow rate of gas or fluid measured by the flow meter in action (iii) and determining that the uterine ablation device is not clogged or embedded in tissue if the flow rate of gas or fluid measured by the flow meter is above the threshold value;