Pystynen, P <br/><br/>
Detection of foetal heart action by ultrasound transformed into audible signals. A comparative study with visual method.  [electronic resource] 

 -  Annales chirurgiae et gynaecologiae Fenniae  1968 
 - 607-10 p.  digital 
<br/><br/> Publication Type: Comparative Study; Journal Article 
<br/><br/><label>ISSN: </label>0003-3855 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Biomedical Engineering<br/>Female<br/>Fetal Heart<br/>Gestational Age<br/>Humans<br/>Methods<br/>Pregnancy<br/>Pregnancy Complications--diagnosis<br/>Time Factors<br/>Ultrasonics--instrumentation<br/>Ultrasonography