Tissue expanders and methods of use

1. A tissue expansion system, comprising:

an implantable device comprising

an expandable chamber, the expandable chamber defined by a posterior backing and a flexible anterior region secured to the posterior backing, and

a rigid gas canister with a compressed gas disposed therein, the rigid gas canister disposed inside the expandable chamber that is defined by the posterior backing and the flexible anterior region,

the rigid gas canister secured relative to the posterior backing with a retention member that is directly attached to the posterior backing, the retention member extending around the rigid gas canister and at least partially surrounding the rigid gas canister, the retention member being flexible and having a hammock configuration within which the rigid gas canister is secured yet freely movable such that the rigid gas canister is not rigidly fixed to the retention member or the expandable chamber,

an antenna secured to the flexible anterior region, the antenna sandwiched between two layers; and

an external controller adapted to wirelessly communicate with the implantable device to cause the release of compressed gas from the rigid gas canister and into the expandable chamber, to thereby expand the expandable chamber, the external controller further comprising a computer executable method adapted to prevent at least one of the release of gas from the rigid gas canister more than three times within about a 24 hour period, or the release of more than 30 mL of gas within about 24 hours.

2. The tissue expansion system of claim 1 , wherein the implantable device further comprises a valve that is adapted to be opened in response to actuation of the external controller to cause the release of the compressed gas from the rigid gas canister and into the expandable chamber.

3. The tissue expansion system of claim 1 , wherein the external controller is adapted to provide power to the implantable portion.

4. The tissue expansion system of claim 1 , further comprising an outer shell surrounding the expandable chamber.