Medical device security is a growing concern with increasing incorporation of complex software and hardware. Security threats exploiting vulnerabilities in medical devices may directly impact patient safety. Standardization and federal organizations are hence, actively involved in setting up new paradigms for guidance and regulation of security throughout the lifecycle. To protect medical devices against threats a risk-based framework that continually manages and assesses security risks along with their proactive addressing is highly recommended. In this paper, we model a multi-modal design approach for risk assessment in medical devices and propose an adaptive remediation scheme to mitigate security threats. Our multi-modal approach is integrated into the hardware-software development with a middleware for interaction between the modes. This provides an effective premarket risk management while the adaptive remediation scheme pro-actively mitigate risk during postmarket deployment. We model our approaches in detail and demonstrate them in a pacemaker design model and deployment scenario.