Lord Dhanvantri is the divine physician who brought with him the knowledge of health, long life and the medical arts. Lord Dhanvantari the Vaidya ratna was one of the 14 Ratnas (Gems) emerged from the ocean. Placing Danvantri yantra is very benefical for good health, it deystroys the negative ions in the surrounding and brings the positivity and good health to the worshipper.
"Om Namo Bhagavathe Vasudevaya
Dhanvataraye Amritha Kalasa Hasthaya
Sarva Maya Vinasanaya Trilokya Nathaya
Sri Maha Vishnave Namah"