Liquidity	3 Months Ended
Mar. 31, 2015
Text Block [Abstract]
Liquidity	Note 2. Liquidity We have funded our operations primarily through product revenue, the issuance of shares of our common stock and the issuance of convertible notes. At March 31, 2015, we had approximately $174.1 million of cash, cash equivalents and available-for-sale investments. Our cash, cash equivalents and available-for-sale investments are expected to be used primarily to fund our ongoing operations including expanding our sales and marketing capabilities on a global basis, research and development (including clinical trials) of new and existing products, components and accessories, regulatory and other compliance functions, acquisition of and investment in third-party technologies as well as for general working capital. We believe our cash, cash equivalents and available-for-sale investment balances are sufficient to support our planned operations for at least the next twelve months. The accompanying unaudited interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States, which contemplate continuation of the Company as a going concern. We have incurred substantial losses from operations since our inception, and losses have continued through March 31, 2015. At March 31, 2015, we had an accumulated deficit of approximately $363.3 million.

Note 2. Liquidity

We have funded our operations primarily through product revenue, the issuance of shares of our common stock and the issuance of convertible notes. At March 31, 2015, we had approximately $174.1 million of cash, cash equivalents and available-for-sale investments. Our cash, cash equivalents and available-for-sale investments are expected to be used primarily to fund our ongoing operations including expanding our sales and marketing capabilities on a global basis, research and development (including clinical trials) of new and existing products, components and accessories, regulatory and other compliance functions, acquisition of and investment in third-party technologies as well as for general working capital. We believe our cash, cash equivalents and available-for-sale investment balances are sufficient to support our planned operations for at least the next twelve months.

The accompanying unaudited interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States, which contemplate continuation of the Company as a going concern. We have incurred substantial losses from operations since our inception, and losses have continued through March 31, 2015. At March 31, 2015, we had an accumulated deficit of approximately $363.3 million.