Abstract: Disclosed herein are inhalation devices and methods for storage and release of substances in powder form such as a drug. The inhalation devices can include a plurality of powder chambers for storing a respective dose of a preloaded powdery substance, and an uncovering device for dispensing one dose at a time. The inhalation devices can include an advancing mechanism is arranged to feed the dose ring one powder chamber at a time. The powder chambers can be oriented in the surface of the dose ring and at least one seal is arranged to seal the powder chambers. The powder chambers can be uncovered or opened to at least a portion of an air channel, and the content of the powder chamber is exposed to, and can pass through, the air channel by means of an air flow.

Abstract: A codeword is generated for transmission in a communications system by generating a first error detection code from information bits, and generating a second error detection code from the information bits and the first error detection code. The information bits, the first error detection code and the second error detection code are then concatenated. The codeword is received by using the first error detection code to make a first determination whether the information bits are error-free, and using the second error detection code to make a second determination whether the information bits and the first error detection code are error-free. The information bits are accepted only if the first determination indicates that the information bits are error-free and the second determination indicates that the information bits and the first error detection code are error-free. The technique is extendable to include additional error detection codes.