Drug delivery devices (1) are described that include sensors (9) and processing circuitry (11) that can detect operating events, such as flow rates and drug delivery, in various types of inhalers, such as dry powder inhalers, metered dose inhalers, nasal inhalers and nebulisers. The information determined by the processing circuitry can be used to provide feedback to the user or can be stored or transmitted for subsequent analysis. This information can be used to improve clinical trials by providing information about the way in which the inhalers under test are being used.
