Usability study of the CU Medical "i-PAD" AED was conducted to validate the usability of the device, primarily focused on the trained user as well as the utility of the training material. Comparing these results of the trained participants to those obtained by Callejas et al. (2004), who studied video-trained users of two commercially available Philips AEDs (FR2 and HS1) using a male manikin only, the participants in this study were more successful (100% vs. 85.7%-FR2 vs. 88.9%-HS1) and faster to shock (58.5s-i-PAD vs. 91s-FR2 vs. 90s-HS1). While the focus of this study was on validating ease of use for trained bystanders, the results of the untrained condition showed that, from a usability perspective, these devices perform as well as any other AEDs already approved and available for purchase for untrained bystander use, as evidenced by the comparison to various published research results.