Methods and systems of optically measuring systolic and/or diastolic blood pressure of a mammal having biological tissue are disclosed herein. In some embodiments, the system comprises an optical blood motion sensor, a gas-sealable inflatable cushion having a flexible and transparent (FOT) barrier section, and an optical blood motion sensor comprising a laser. When pressure (e.g. at least systolic pressure) illuminates the tissue, laser light may pass en route to the tissue through the FOT sealing barrier section of the gas-sealable inflatable cushion as well as cushion interior. In some embodiments, a rigid restrictor comprising an optically transparent section is provided, and laser light also passes through the optically transparent section of the rigid restrictor en route to the biological tissue.