A hydrogenated ring-opening metathesis polymer which contains at least a structural unit B of the following general formula 3 andor a structural unit C of the following general formula 4: . The content of the water-soluble organic solvent is from 5 weight % to 30 weight % relative to the total amount of the ink composition. It receives the signal from an NIBP sensor and determines the blood pressure corresponding to the signal. The output mirror is arranged to receive the light beam reflected by the input mirror and reflects the light beam into the output collimator. The antenna device comprises a first grounded conductor, an antenna element mounted on the first grounded conductor via an insulator, a second grounded conductor disposed separate from the first grounded conductor, and a changing unit for changing directivity of the antenna element by adding the second grounded conductor to the first grounded conductor or canceling the addition thereof.