The invention provides a method of using an apparatus for manipulating matter in a confined or inaccessible space, comprising providing an apparatus having manipulator means at least partly constructed of one or more bent or twisted elongate shape memory alloy members having pseudoelasticity at the intended manipulation temperature, and a hollow housing or cannula capable of holding at least the shape memory alloy member(s) in a relatively straightened state, and actuating means for extending the shape memory alloy member(s) from the housing to manipulate matter within the space and for withdrawing the shape memory alloy member(s) into the housing, the arrangement being such that the shape-memory alloy member(s) bend(s) or twist(s) pseudoelastically in a lateral or helical sense to manipulate the matter on extending from the housing at the manipulation temperature, and become(s) relatively straightened on withdrawal into the housing at the temperature.