This is the first part of a research work to study the reliability of the Gas Discharge Visualization (GDV) device and the Bio-Well, two biofield machines based on the Kirlian effect and electrophotonic imaging. Their working, accuracy, and usefulness were analyzed in a Pranic Healing experiment, which is reported in the second part of this study. Here the scientific literature concerning Pranic Healing and Kirlian photography, as well as the functioning of these biofield machines, are reviewed. Pranic Healing has been practiced in Ayurveda for millennia, in order to restore and promote health, by manipulating the flow of subtle energy Prana throughout the human organism. Kirlian photography has been used for decades to measure the human energy field, in order to assess its bioenergetic condition and potential, as well as validate a variety of therapeutic modalities. In the second part of this work, previous reliability studies on Kirlian photography devices will be reviewed, drawing negative conclusions about the utility of these machines in biofield science. An original experiment will also be presented, where the GDV device and the Bio-Well were utilized to evaluate the effect of Pranic Healing on human and water energy fields, with controls. Results were inconsistent, showing the limitations of these technologies, highlighting their incapacity to return meaningful bioenergetic information, and thus suggesting that their use in biofield science should be revisited.