Abstract: A folding game board is provided which consists of a unitary thin plastic member divided into segments by at least one pair of parallel grooves having nadirs separated by a zenith. Each folding segment has one or more ridges on its face, preferably at least two of them in non-parallel planes perpendicular to the face, and a main body or segment of the board having corresponding ridges defining surfaces in non-parallel planes perpendicular to the face, non-parallel planes being aligned so that the mating ridge surfaces provide a frictional interface therebetween when the segments are folded at the nadirs into juxtaposition with the main body of the board. Preferably, one of the nadirs will be shallower than the other of the nadirs so as to increase the force exerted by the folding junction to maximize the frictional normal force.

Abstract: A transducer sytem comprising a plurality of patient mounted transmitters, each of the transmitters including means for generating an asymmetric wave or a variable periodic pulse train, the asymmetry or variable periodicity of said pulse train being proportional to the quantity being transduced, each of said transmitters including an output electrode. A receiver is also provided including portable hand held input electrode electrostatically coupled to one of the transmitter electrodes, the receiver including means for converting the variable periodicity or asymmetry to a magnitude representative of the transduced quantity in proportion to the variable periodicity or asymmetry.