iHealth heart rate monitor

hrate.py

#!/usr/bin/env python
#
# BSD 3-Clause License
#
# Copyright (c) 2023-2024 Fred W6BSD
# All rights reserved.
#

__doc__ = """
Read the CSV file from the iHealth heart rate monitor and generate a graph.
https://ihealthlabs.com/products/ihealth-track-connected-blood-pressure-monitor
 """
import argparse
import csv
import os
import warnings
from collections import defaultdict
from datetime import datetime, timedelta

import matplotlib.dates as mdates
import matplotlib.pyplot as plt
import numpy as np
from matplotlib import ticker

DPI = 300
TREND_DAYS = 7
DARKBLUE = "#1d1330"
LIGHTBLUE = "#e1f7fa"
GRAY = "#4b4b4b"
LIGHTGRAY = "#ababab"

RC_PARAMS = {
  "axes.edgecolor": GRAY,
  "axes.facecolor": DARKBLUE,
  "axes.facecolor": DARKBLUE,
  "axes.labelcolor": LIGHTGRAY,
  "figure.edgecolor": DARKBLUE,
  "figure.facecolor": DARKBLUE,
  "font.size": 10,
  "lines.linewidth": 1,
  "lines.markersize": 5,
  "text.color": "white",
  "xtick.color": LIGHTGRAY,
  "xtick.color": LIGHTGRAY,
  "xtick.labelcolor": LIGHTGRAY,
  "ytick.color": LIGHTGRAY,
  "ytick.color": LIGHTGRAY,
  "ytick.labelcolor": LIGHTGRAY,
}


def read_ihealth(filename: str) -> set:
  data = defaultdict(lambda: list([[], [], []]))
  with open(filename, 'r', encoding='utf-8') as fdi:
    reader = csv.reader(fdi)
    next(reader)
    for line in reader:
      sdate = line[0] + ',' + line[1]
      date = datetime.strptime(sdate, '%Y-%m-%d,%H:%M')
      date = date.replace(minute=0)
      data[date][0].append(float(line[2]))
      data[date][1].append(float(line[3]))
      data[date][2].append(float(line[4]))
  return sorted(list(data.items()))


def interval(data, gnr=24):
  delta = mdates.num2date(np.max(data)) - mdates.num2date(np.min(data))
  return int(int(delta.days < gnr) + delta.days / gnr)


def graph(data, image='/tmp/ihealth.jpg', trend_days=TREND_DAYS):
  dates = np.array([np.datetime64(d[0]) for d in data])
  dstart = dates.max() - np.timedelta64(trend_days, 'D')
  systolic = np.array([np.mean(d[1][0]) for d in data], dtype=np.int32)
  diastolic = np.array([np.mean(d[1][1]) for d in data], dtype=np.int32)
  hrate = np.array([np.mean(d[1][2]) for d in data], dtype=np.int32)
  idx = dates[:] > dstart
  dates = mdates.date2num(dates)
  with warnings.catch_warnings(action="ignore"):
    systolic_t = np.poly1d(np.polyfit(dates[idx], systolic[idx], 1))
    diastolic_t = np.poly1d(np.polyfit(dates[idx], diastolic[idx], 1))

  plt.rcParams.update(RC_PARAMS)
  plt.title("Fred's BP")
  plt.subplots_adjust(hspace=0.3)

  fig, (axp, axr) = plt.subplots(2, 1, figsize=(12, 9),
                                 gridspec_kw={'height_ratios': [2, 1]})
  axp.set_title('Blood Pressure', fontstyle='italic')
  axp.plot(dates, systolic, marker='o', label='SYS', color='tab:blue')
  axp.plot(dates, diastolic, marker='o', label='DIA', color='tab:orange')
  axp.plot(dates[idx], systolic_t(dates[idx]), color='tab:cyan',
           label=f'Trend ({trend_days} Days)')
  axp.plot(dates[idx], diastolic_t(dates[idx]), color='tab:cyan')

  axp.set_ylabel('mmHg')
  axp.set_ylim([diastolic.min() * .70, systolic.max() * 1.1])
  axp.yaxis.set_minor_locator(ticker.AutoMinorLocator(2))
  axp.xaxis.set_major_formatter(mdates.DateFormatter('%m/%d'))
  axp.xaxis.set_major_locator(mdates.DayLocator(interval=interval(dates)))
  axp.set_xticklabels([])

  axp.margins(0.025)
  axp.legend(loc="upper left", fontsize="10")
  axp.grid(linestyle="solid", linewidth=.5, alpha=.25)
  axp.grid(which='minor', linestyle="dotted", linewidth=.25)
  axp.tick_params(axis='x', labelrotation=45, labelsize=8)

  axr.margins(4, 4)
  axr.set_title('Heart Rate', fontstyle='italic')
  axr.plot(dates, hrate, marker='o', label='Heart Rate', color="tab:cyan")
  axr.set_ylabel('bpm')
  axr.set_ylim([hrate.min() / 3, hrate.max() * 1.3])
  axr.yaxis.set_minor_locator(ticker.AutoMinorLocator(2))
  axr.xaxis.set_major_formatter(mdates.DateFormatter('%m/%d'))
  axr.xaxis.set_major_locator(mdates.DayLocator(interval=interval(dates)))
  axr.margins(0.025)
  axr.legend(loc="upper left", fontsize="10")
  axr.grid(linestyle="solid", linewidth=.5, alpha=.25)
  axr.grid(which='minor', linestyle="dotted", linewidth=.25)
  axr.tick_params(axis='x', labelrotation=45, labelsize=8)

  fig.savefig(image, transparent=False, dpi=DPI)
  print(f'{image} saved')


def main():
  parser = argparse.ArgumentParser(description="iHealth heart rate plotter")
  parser.add_argument('-f', '--file', required=True)
  parser.add_argument('-o', '--output', required=True)
  parser.add_argument('-t', '--trend-days', type=int, default=TREND_DAYS)
  opts = parser.parse_args()

  if not os.path.exists(opts.file):
    print(f'File: {opts.file} Not found')
    return os.EX_IOERR

  data = read_ihealth(opts.file)
  graph(data, opts.output, opts.trend_days)
  return os.EX_OK


if __name__ == "__main__":
  main()

iHealth.png