Using ultrasound shear-waves to enhance skin permeability

A system comprising:

• an extracellular-fluid collection device configured to be positioned at a location on a skin of a mammal;
• an ultrasonic wave transmitter configured to emit ultrasonic shear waves directed at the location, the ultrasonic shear waves having a frequency or amplitude selected to increase a permeability of the skin of the mammal to an extracellular-fluid;
• a sensor configured to determine a rate or amount of extracellular-fluid collected by the extracellular-fluid collection device;
• and
• a fluid collection controller configured regulate a parameter of ultrasonic shear waves transmitted by the ultrasonic wave transmitter in response to the determined rate or amount of extracellular-fluid collected by the extracellular-fluid collection device.

A system comprising:

• an extracellular-fluid collection device configured to be positioned at a location on a skin of a mammal;
• an ultrasonic wave transmitter configured to emit ultrasonic shear waves directed at the location, the ultrasonic shear waves having a frequency or amplitude selected to increase a permeability of the skin of the mammal to an extracellular-fluid;
• a cavitation sensor configured to determine a cavitation event in the mammal responsive to the emitted ultrasonic shear waves;
• and
• a cavitation controller configured to limit a power of the ultrasonic shear waves directed at the location to a level below a cavitation threshold of the mammal.