RecruitingDevice studyUltrasound for Healthy AgingThe investigators will study the effects of an ultrasound bath device that uses low-frequency ultrasound on the healthy aging. Participants will have before and after ultrasound assessments of muscle and thinking skills, aging related to the immune system, and body make-up. The group that is assigned to get the ultrasound will have low-frequency ultrasound in a bathtub for 45 minutes, three times weekly for 8 weeks, and the control group will be in the bathtub without the ultrasound turned on.