The invention describes a steerable sheath for percutaneous epicardial access. The gas-permeable plug has a plug body and a permeable sheet including therein countless minute permeable pores. Additionally, the batteries are charged to a certain state or the batteries are maintained at a particular state of charge. The door moves at an increasing rate of speed from its closed to open positions and a decreasing rate of speed from its open to closed positions. The disclosure reduces the manufacturing cost, and satisfies the design requirements of low cost mobile phones such as bar phones.