2018-02-142018-02-141981-02-10http://hdl.handle.net/2152.3/5727This image reflects a letter written by Jack Hammond of Del Mar Avionics to Arnold Mandell and Michael Blackburn regarding Heart Rate Variance .Heart Rate VarianceDel Mar AvionicsJack HammondArnold MandellMichael BlackburnWilliam ThorntonJohn WallaceUTMBSpace MedicineletterBlood Pressure MonitorAmbulatoryNorman Holter