US Patent 11759369 Negative pressure treatment including mechanical and chemical pump

A negative pressure assembly includes a drape, a sealing element, a reactor, a valve and a mechanical pump assembly. The drape and the sealing element, when applied to the skin, cooperate to define an enclosed volume. The reactor is located so as to be in fluid communication with the enclosed volume when the drape is covering the dressing site. The reactor reacts with a selected gas found in air to consume the selected gas. The valve has a first operating state in which gas is drawn from the enclosed volume through the valve. The mechanical pump assembly includes a pump chamber fluidly connectable to the enclosed volume through the valve when the valve is in the first operating state. The mechanical pump is configured to fluidly connect with the enclosed volume and draw air from the enclosed volume into the pump chamber.