
    Write a function that validates medical parameter identifiers by checking if they follow the standard format of lowercase letters joined with underscores (e.g., "heart_rate", "blood_pressure_systolic"). The function should return true if the parameter identifier follows this format and false otherwise, ensuring proper integration of vital sign measurements into the patient monitoring system.
    

    
import re

def text_lowercase_underscore(text):
    """
    Write a function that validates medical parameter identifiers by checking if they follow the standard format of lowercase letters joined with underscores (e.g., "heart_rate", "blood_pressure_systolic"). The function should return true if the parameter identifier follows this format and false otherwise, ensuring proper integration of vital sign measurements into the patient monitoring system.
    

    """
import re

def text_lowercase_underscore(text):
    """
    Write a function that validates medical parameter identifiers by checking if they follow the standard format of lowercase letters joined with underscores (e.g., "heart_rate", "blood_pressure_systolic"). The function should return true if the parameter identifier follows this format and false otherwise, ensuring proper integration of vital sign measurements into the patient monitoring system.
    

    """
    patterns = '^[a-z]+_[a-z]+$'
    if re.search(patterns, text):
        return True
    else:
        return False