Inventors have created a number of medical device peripherals that attach to mobile phones in recent years. This past week we wrote about an iPhone peripheral LED light that illuminates flourescent ink "tattooed" under a person's skin to detect sodium levels or blood glucose levels. In years past we've covered peripherals that transform inexpensive mobile phones into microscopes, mini eye exam machines, and more.

Read on for our roundup of seven mobile phone peripheral devices you should know...

Cellscope

Cellscope takes a standard cell phone and transforms it into a compact, high-resolution, handheld microscope with the capability of on-site disease diagnosis and wireless transmission of patient data to clinical centers for remote diagnosis and treatment. The company is currently piloting a program focused on at-home diagnosis of pediatric infections. It was developed by Dr. Daniel Fletcher, Dr. Erik Douglas and Dr. Wilbur Lam of the University of California at Berkeley. Cellscope was also one of the startups chosen to be a part of mHealth incubator Rock Health's first class of 2011 startups.

Agamatrix's IBGStar

IBGStar is a blood glucose meter plug-in for the iPhone from Sanofi, with the plugin module created by Agamatrix. The forthcoming iPhone BGM plug-in will interact with a not yet Apple-approved iBGStar Diabetes Manager App that will help users track blood glucose, carbs intake and insulin dose. Agamatrix already offers such an app for iPhone users under its Wavesense brand, however, that application does not pair with a blood glucose meter.