""As a young surgeon, Dad was the first American to devise and perform a total organ replacement. Later, he came up with a device that saved thousands of soldiers' lives during the Vietnam War. The Heimlich Chest Drain Valve is still used worldwide for patients undergoing chest surgery." Clearly Heimlich should be known for more than the HM.
My dad (a doctor) did so once decades ago, while working in a hospital in Ghana. His patient was a man with a collapsed lung. IIRC, he took a surgeon glove, cut off the tips of two fingers, attached one to a tube, and made a knot in the wrist (so it became kind of like a balloon with two openings). The tube was attached to the lung, to drain fluid. The glove was partially submerged in a bucket of water, so it now functioned like a valve: when the patient breathed out, air and fluid could escape from the glove. When he breathed in, the suction plus water pressure would "seal off" the glove.