Numerous studies have shown that trained dogs can detect many kinds of disease — including lung, breast, ovarian, bladder, and prostate cancers, and possibly Covid-19 — simply through smell. In some cases, involving prostate cancer for example, the dogs had a 99 percent success rate in detecting the disease by sniffing patients’ urine samples. But it takes time to train such dogs, and their availability and time is limited. Scientists have been hunting for ways of automating the amazing olfactory capabilities of the canine nose and brain, in a compact…