From my experience, I know that implants started to be used around 70 years ago. The older implants are physical and caused an issue with humans. They were often rejected by the human body. As time progressed the implant technology improved. Just to divert for a moment - The implants had to be modified for the human race, as they were also used on other races. This is due to the hybridization process. And so, many races now use etheric implants, and generally spirit people when doing healings cannot see ET-based implants them and that's definitely become an issue. The implants range from communication devices all the way through to spinal clamps (I have no idea why those ones are used but I have removed two with the Zetas). Implant removal is a very real issue and the reason is that they generally have a locking mechanism and if not deactivated before removal, the technology returns if not deactivated or worse, damages the persons body if removed by the race who didn't put it there in the first place. Spirits and Humans (working with Reiki energy, crystals or any other modality) are unable to detect an etheric implant or remove extraterrestrial etheric implants. Although it may look as though they have been removed, the reality is, is that they have not been.