Abstract: A new method and apparatus is provided for as a wearable, self-contained, non-invasive device for the instantaneous measurement of blood glucose in an individual. This invention uses the measurement and comparison of ultrasound wave velocities to determine the instant value of glucose concentration in the individual. In particular, it uses ultrasound waveforms in the “A” operational mode, depth determination, rather than typical imaging operational modes. Two distinct and different ultrasound frequencies are transmitted into the body and their total propagation times, from insert to bone-reflected echo return signal, are timed to calculate the signal dependent velocities affected by glucose. It is applicable to all forms of human body conditions, regardless of size, weight, age or health condition. It can be adapted for use in a closed loop system for insulin delivery on an “as-needed basis.