mdrd_gfr_calculator.py•6.08 kB
"""
MDRD GFR Calculator
"""
import math
from typing import Dict, Any
from medcalc import (
BaseCalculator,
CalculatorInfo,
Parameter,
ParameterType,
ValidationResult,
CalculationResult,
register_calculator
)
from medcalc.utils import round_number
@register_calculator("mdrd_gfr")
class MDRDGFRCalculator(BaseCalculator):
"""MDRD肾小球滤过率计算器实现"""
def get_info(self) -> CalculatorInfo:
return CalculatorInfo(
id=9,
name="MDRD GFR Equation",
category="nephrology",
description="Estimate glomerular filtration rate using the MDRD equation",
parameters=[
Parameter(
name="age",
type=ParameterType.NUMERIC,
required=True,
unit="years",
min_value=18,
max_value=120,
description="Age in years"
),
Parameter(
name="sex",
type=ParameterType.CHOICE,
required=True,
choices=["Male", "Female"],
description="Patient sex"
),
Parameter(
name="creatinine",
type=ParameterType.NUMERIC,
required=True,
unit="mg/dL",
min_value=0.1,
max_value=20.0,
description="Serum creatinine in mg/dL"
),
Parameter(
name="race",
type=ParameterType.CHOICE,
required=False,
choices=["Black", "Non-Black"],
default="Non-Black",
description="Patient race"
)
]
)
def validate_parameters(self, parameters: Dict[str, Any]) -> ValidationResult:
"""验证参数"""
errors = []
# 获取参数值（直接从字典获取）
age = parameters.get("age")
creatinine = parameters.get("creatinine")
sex = parameters.get("sex")
# 检查必需参数
if age is None:
errors.append("Missing required parameter: age")
if creatinine is None:
errors.append("Missing required parameter: creatinine")
if sex is None:
errors.append("Missing required parameter: sex")
# 验证数值范围
if age is not None:
if not isinstance(age, (int, float)) or age < 18 or age > 120:
errors.append("Age must be between 18 and 120 years")
if creatinine is not None:
if not isinstance(creatinine, (int, float)) or creatinine < 0.1 or creatinine > 20.0:
errors.append("Creatinine must be between 0.1 and 20.0 mg/dL")
# 验证性别
if sex is not None and sex not in ["Male", "Female"]:
errors.append("Sex must be 'Male' or 'Female'")
return ValidationResult(
is_valid=len(errors) == 0,
errors=errors
)
def calculate(self, parameters: Dict[str, Any]) -> CalculationResult:
"""执行计算"""
age = parameters.get("age")
sex = parameters.get("sex")
creatinine = parameters.get("creatinine")
race = parameters.get("race", "Non-Black")
# 确定系数
race_coefficient = 1.212 if race == "Black" else 1.0
gender_coefficient = 0.742 if sex == "Female" else 1.0
# 计算MDRD GFR: GFR = 175 × Cr^(-1.154) × 年龄^(-0.203) × 种族系数 × 性别系数
gfr = round_number(
175 *
math.exp(math.log(creatinine) * -1.154) *
math.exp(math.log(age) * -0.203) *
race_coefficient *
gender_coefficient
)
# 生成解释
explanation = self._generate_explanation(age, sex, creatinine, race,
race_coefficient, gender_coefficient, gfr)
return CalculationResult(
value=gfr,
unit="mL/min/1.73m²",
explanation=explanation,
metadata={
"age": age,
"sex": sex,
"creatinine": creatinine,
"race": race,
"race_coefficient": race_coefficient,
"gender_coefficient": gender_coefficient,
"formula": "GFR = 175 × Cr^(-1.154) × Age^(-0.203) × Race × Gender"
}
)
def _generate_explanation(self, age: float, sex: str, creatinine: float, race: str,
race_coefficient: float, gender_coefficient: float, gfr: float) -> str:
"""生成计算解释"""
explanation = f"Patient age: {age} years\n"
explanation += f"Serum creatinine: {creatinine} mg/dL\n\n"
if race == "Black":
explanation += "The patient is Black, so the race coefficient is 1.212.\n"
else:
explanation += "The patient is not Black, so the race coefficient is defaulted to 1.0.\n"
if sex == "Female":
explanation += "The patient is female, so the gender coefficient is 0.742.\n"
else:
explanation += "The patient is male, so the gender coefficient is 1.\n"
explanation += f"\nThe patient's estimated GFR is calculated using the MDRD equation as:\n"
explanation += f"GFR = 175 * creatinine^(-1.154) * age^(-0.203) * race_coefficient * gender_coefficient. The creatinine concentration is in mg/dL.\n"
explanation += f"Plugging in these values will give us: 175 * {creatinine}^(-1.154) * {age}^(-0.203) * {race_coefficient} * {gender_coefficient} = {gfr}.\n"
explanation += f"Hence, the patient's GFR is {gfr} mL/min/1.73m²."
return explanation