The base of the wheel­chair is a three-link lambda mech­a­nism with two fixed joints.

Com­par­ing the pho­tos stored at CNAM with the pre­served mech­a­nism in St. Peters­burg shows that the orig­i­nal ver­sion (rep­re­sented in the pho­tos) was refined later — the wheels made of iron strips were replaced by wheels with tires and the side­walls were added.