1897
AIM : This study was carried out to determine the effect of injection duration on bruising and pain following the administration of the subcutaneous injection of heparin .
 bruising, pain, heparin
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 bruising, pain, heparin