Stimulating cell activity within a tissue is performed by an ultrasound array transducer having a plurality of transducer elements and a controller that actuates a plurality of transducer elements to emit focused acoustic energy to a plurality of focal zone locations in a scan direction at a focal zone scan rate. The actuation of the plurality of transducer elements to emit focused acoustic energy to the plurality of focal zone locations in the scan direction at the focal zone scan rate is repeated for a plurality of sweep cycles at a sweep rate which stimulates cells for optimal tissue growth.