fis_lib_measure/lib/process/calcuators/formulas/cardiac.dart

import 'dart:math' as math;

import 'package:fis_measure/utils/number.dart';

class CardiacFormulas {
  CardiacFormulas._();

  /// <summary>
  /// IMP=(CO-ET)/ET
  /// </summary>
  /// <param name="co">s</param>
  /// <param name="et">s</param>
  /// <returns>(unit None)</returns>
  static double teiIndex(double co, double et) {
    double imp = 0.0;
    if (et != 0.0) {
      imp = (((co).abs() - (et).abs()) / et).abs();
    }
    return imp;
  }

  /// <summary>
  /// EF = (EDV - ESV )/EDV
  /// </summary>
  /// <param name="edv">cm³</param>
  /// <param name="esv">cm³</param>
  /// <returns>None</returns>
  static double ef(double edv, double esv) {
    // 这行判断暂时注释掉是为了使实际表现与旧版一致
    // if (edv < esv) {
    //   return double.nan;
    // }
    return (edv - esv) / edv * 100;
  }

  /// <summary>
  /// EDV (Teichholz) = [7.0/(2.4 + LVIDd)] x LVIDd^3
  /// </summary>
  /// <param name="lvidd">Unit cm</param>
  /// <returns>cm³</returns>
  static double edvTeichholz(double lvidd) {
    double edv = double.nan;
    if (!NumUtil.almostEquals(lvidd, 0)) {
      edv = 7.0 * math.pow(lvidd, 3) / (2.4 + lvidd);
    }
    return edv;
  }
}