It’s a digital lifeline. Physicians for Human Rights say Assad’s forces have killed nearly 700 medical workers, often deliberately. And like so many aspects of the Arab Spring-turned-winter, the battlefield dressing for the shortfall lies with technology. Western doctors using texts and webcams are remotely training and consulting with medics in an underground network of field hospitals in rebel-held areas — some powered by animal waste. London surgeon David Nott, who volunteered during the Bosnian conflict to treat the wounded, is now committed to assuring such facilities survive the onslaught.