You may have heard of doctors being oncall. But, ever heard of a portable ultrasound machine ? A rising number of portable ultrasound machines are being registered as being “on call”, or the devices could be taken anywhere anytime to conduct an ultrasound test. Delhi was the first state to register such “on-call” portable ultrasound machines, a trend that has now spread across the country. The Union health ministry says the trend is in violation of the Pre-conception and Pre-natal Diagnostic Techniques Act (PC & PNDT Act), which allows ultrasound machines to be portable only within the premises of hospital or clinic registered under the Act.