  To support the dynamic composition of various devices/apps into a medical
system at point-of-care, a set of communication patterns to describe the
communication needs of devices has been proposed. To address timing
requirements, each pattern breaks common timing properties into finer ones that
can be enforced locally by the components. Common timing requirements for the
underlying communication substrate are derived from these local properties. The
local properties of devices are assured by the vendors at the development time.
Although organizations procure devices that are compatible in terms of their
local properties and middleware, they may not operate as desired. The latency
of the organization network interacts with the local properties of devices. To
validate the interaction among the timing properties of components and the
network, we formally specify such systems in Timed Rebeca. We use model
checking to verify the derived timing requirements of the communication
substrate in terms of the network and device models. We provide a set of
templates as a guideline to specify medical systems in terms of the formal
model of patterns. A composite medical system using several devices is subject
to state-space explosion. We extend the reduction technique of Timed Rebeca
based on the static properties of patterns. We prove that our reduction is
sound and show the applicability of our approach in reducing the state space by
modeling two clinical scenarios made of several instances of patterns.
