The PhD program at Johns Hopkins University has several requirements, most notably fulfilling the class requirements, passing the Graduate Board Oral Exam (GBO), proposing a thesis, and defending the thesis. 

The official PhD Program requirements can be found here: http://www.bme.jhu.edu/academics/phd/phd_curricula.htm

References

• JHU BME PhD Academics: http://www.bme.jhu.edu/academics/phds.htm
• JHU BME PhD Program Curricula: http://www.bme.jhu.edu/academics/phd/phd_curricula.htm
• JHU BMe PhD Handbook: http://www.bme.jhu.edu/academics/phd/phdstudhandbook/phd_fs_hand.html