Q. Looking for a biography on an individual who somehow shaped the christian church, preferably in the medical field.
Generally speaking most biographies will include 'biography' in the subject, so you can always do an advanced search and enter 'biography' searched as subject in the first search, then enter another descriptor as keywords to help limit it to a particular type or field of biographies.
In particular, to find biographies of individuals who have shaped the Christian church working in medical work is to do a subject search in Research Central for Missionaries, Medical – Biography. This would give you specifically missionaries who work with medicine as a part of their work for the church.
This link should give you access to the search in Research Central. If you wish to limit to items we have in WWU, you can select Available at WWU option at the top of the search. Or if you have a little bit of time you can also look through items that are available in Summit. These can be requested using the Availability & Request Options and logging into your account. Summit items will usually take a week to arrive but can then be checked out for 6 weeks.