Yesterday, Google announced a service codenamed Bouncer, which "provides automated scanning of Android Market for potentially malicious software without disrupting the user experience of Android Market or requiring developers to go through an application approval process."
Here’s how it works: once an application is uploaded, the service immediately starts analyzing it for known malware, spyware and trojans. It also looks for behaviors that indicate an application might be misbehaving, and compares it against previously analyzed apps to detect possible red flags.
Given all the concerns around security and privacy in the world of health care, this could be a technology that could improve patient safety.
You can read more about "Bouncer" on the Google Mobile Blog.