The Rife Machine is considered to be an alternative medical marvel by many who report that it has cured them of cancer, parasites and numerous other ailments.  Conventional medicine generally says that is useless and a fraud.  You'll have to decide for yourself.

Royal Raymond Rife invented this machine in the 1930s, based upon his work with high-magnification optical microscopes.  He claimed to be able to see microbes with his microscope which were too small to see with the existing technology.   He also claimed that these microbes could be destroyed by directing specific frequencies at them.  If the microbes were destroyed, the disease that they were causing could be cured.  For many years, this was considered to be a 'science fiction' claim, with no validity. 

It would appear that one major problem with the Rife Machine has been the difficulty of delivering the exact frequency that will kill what is 'bad' while not harming what is 'good'.  It is said that each 'bad' organism can only be destroyed with its own specific frequency.  One of the major hurdles has been knowing what frequency was needed in order to kill a specific disease organism.  At least one company claims to be able to supply this information.  Currently, research at Tufts University, among others, is studying the use of implanted medical devices which will utilize terahertz frequencies. 

In 1993, Dr. Hulda Clark developed the Zapper to kill bacteria, viruses and parasites.  This machine uses the principle of resonance to create a special electronic wave that uses only one frequency that is said to include all of the vibration (kill) frequencies of these organisms, thus destroying them.  

There are a number of different Rife machines available to the consumer, all rather expensive.  Anyone who is interested in this technology should do their research and get recommendations from those who are knowledgeable in this subject.