This is a stylized version of Medicine Master Buddha’s Mantra with 108 repetitions.

Below are quotes from Master Hsuan Hua‘s commentary on The Sutra of the Merit and Virtue of the Past Vows of Medicine Master Vaiḍūrya.

Sūtra:
At that time, the World-Honored One entered a samādhi called “extinguishing the suffering and distress of all beings.” After he entered this samādhi, a great light came forth from the prominence on top of his head. From amid that light he proclaimed this magnificent dhārāṇi:

Na mo bo qie fa di. Bi sha she. Ju lu bi liu li. Bo la po. He la she ye. Da tuo jie duo ye. E la he di. San miao san pu tuo ye. Da zhi tuo nan. Bi sha shi. Bi sha shi. Bi sha she. San mo jie di. Suo he.
…

Commentary:
If you recite this very short mantra faithfully and single-mindedly, you will find that it has infinitely many wonderful functions. A doctor can use this mantra to enable his patients to have a speedy recovery. With the mantra’s help, he can become an extremely good doctor. Everyone, whether you are a doctor or not, should recite this mantra. If you recite it on behalf of sick people, they will soon get well.

The mantra consists of transliterated sounds, which cannot be explained. You are not supposed to understand what the mantra means. It is wonderful precisely because it is not understood.