Soft balloon device and system

A system for ablating tissue, the system comprising:

• a treatment device including:
• an elongate body having a distal portion, a proximal portion, at least one lumen, and a pressure sensor,
• a shaft slidably disposed within the elongate body, the shaft having a proximal portion and a distal portion;
• a balloon having a distal neck and a proximal neck, the distal neck being coupled to the distal portion of the shaft and the proximal neck being coupled to the distal portion of the elongate body;
• a handle, the handle being fixedly coupled to the proximal portion of the elongate body;
• and
• a push button being in mechanical communication with the shaft, the push button being movable to a first position where the push button is depressed and a second position where the push button is released, movement of the push button to the first position exerts a force on the shaft and movement of the push button to the second position releases the force on the shaft so the shaft is freely movable with respect to the handle and the elongate body and causes the balloon to inflate,
• a control unit including:
• processing circuitry;
• a coolant supply reservoir, in fluid communication with the balloon;
• a pressure sensor that is in fluid communication with the coolant supply reservoir;
• and
• a vacuum source;
• a fluid delivery conduit between the coolant supply reservoir and the balloon;
• and
• a fluid return conduit between the balloon and the vacuum source,
• the processing circuitry being configured to adjust a flow of coolant through the fluid delivery conduit and the fluid return conduit to maintain the balloon at a balloon pressure of between 0.2 psig and 3.0 psig during both an inflation phase and an ablation phase, the processing circuitry being further configured to control the balloon pressure independently of a flow rate of coolant from the coolant supply reservoir.

A method of performing a medical procedure, the method comprising:

• selecting a desired inflated size of a balloon of a treatment device;
• delivering a fluid to the balloon and withdrawing coolant from the balloon such that the balloon is inflated to the desired inflated size and has a pressure of between 0.2 psig and 3.0 psig;
• delivering a coolant to the balloon at a flow rate and maintaining the balloon at the pressure of between 0.2 psig and 3.0 psig, the pressure being controlled independently of the flow rate of the coolant, delivery of the coolant to the balloon reducing a temperature of the balloon to a temperature sufficient to cryoablate tissue;
• manipulating a push button in a handle of the treatment device to move a shaft in a proximal direction and a distal direction opposite the proximal direction while coolant is being delivered to the balloon, movement of the shaft to advance the shaft in a proximal-to-distal direction being configured to elongate the balloon and retraction of the shaft in a distal-to-proximal direction being configured to transition the balloon to a substantially toroidal configuration;
• positioning the treatment device such that the balloon is in contact with an area of targeted tissue;
• determining whether the balloon has reached the desired inflated size based on at least one pressure measurement received from at least one pressure sensor disposed within the balloon;
• and
• cryoablating the area of targeted tissue with the balloon once it is determined that the balloon has reached the desired inflated size with a constant pressure of between 0.2 psig and 3.0 psig.