Implantable body-driven shunt pump

An implantable, body-driven shunt pump, comprising:

• a pump body defining a fluid inlet, a fluid outlet and a fluid chamber therebetween;
• an inlet valve arranged in said fluid inlet, said inlet valve being a one-way valve arranged such that it is operable to allow fluid flow into said fluid chamber and to prevent fluid flow out of said fluid chamber;
• and
• an outlet valve arranged in said fluid outlet, said outlet valve being a one-way valve arranged such that it is operable to allow fluid flow out of said fluid chamber and to prevent fluid flow into said fluid chamber,
• wherein said pump body comprises a plurality of expandable and contractible components that change the volume of the fluid chamber in response to a change in pressure of fluid in said fluid chamber,
• wherein said pump body has a substantially rigid outer surface in a section defining said fluid chamber, wherein the substantially rigid outer surface in the section defining said fluid chamber pump body comprises silicone.