Validity of the Actigraph-GT9X accelerometer for measuring steps and energy expenditures in heart failure patients. - Kim, Jisu; Kenyon, Jonathan; Billingsley, Hayley; Bohmke, Natalie; Ahmed, Syed Imran; Salmons, Hannah; Lee, Jung-Min; Kirkman, Danielle; Carbone, Salvatore; Kim, Youngdeok (PLoS ONE, 2024)