FiO2Calculator.github.io/hybridHIW.html at main · FiO2Calculator/FiO2Calculator.github.io · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
<!doctype html>
<html>

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>FiO2 Calculator</title>
  <link rel="stylesheet" href="style.css">
  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@4.5.3/dist/css/bootstrap.min.css"
    integrity="sha384-TX8t27EcRE3e/ihU7zmQxVncDAy5uIKz4rEkgIXeMed4M0jlfIDPvg6uqKI2xXr2" crossorigin="anonymous">

  <script>
  </script>

</head>

<body>
  <header>
    <h4>FiO2 Calculator</h4>
    <div class="nav">
      <ul>
        <li>
          <a href="aboutUs.html" class="btn btn-secondary" role="button" aria-pressed="true">
            About Us
          </a>
        </li>
      </ul>
    </div>
  </header>
  <nav class="navbar navbar-expand navbar-light bg-light">

    <div class="collapse navbar-collapse justify-content-center" id="navbarNav">
      <ul class="navbar-nav">
        <li class="nav-item active">
          <a class="nav-link" href="index.html">Home</a>
        </li>
        <li class="nav-item active">
          <div class="dropdown">
            <a class="nav-link active dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown"
              aria-haspopup="true" aria-expanded="false">
              Calculators
            </a>
            <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
              <a class="dropdown-item" href="finer.html">Finer</a>
              <a class="dropdown-item" href="bb.html">Benaron-Benitz</a>
              <a class="dropdown-item" href="hybrid.html">Hybrid</a>
            </div>
          </div>
        </li>
        <li class="nav-item active">
          <div class="dropdown">
            <a class="nav-link active dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown"
              aria-haspopup="true" aria-expanded="false">
              How it Works
            </a>
            <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
              <a class="dropdown-item" href="finerHIW.html">Finer</a>
              <a class="dropdown-item" href="bbHIW.html">Benaron-Benitz</a>
              <a class="dropdown-item" href="hybridHIW.html">Hybrid</a>
            </div>
          </div>
        </li>
      </ul>
    </div>
  </nav>

  <div class="page-content">
    <h5>More details on Hybrid:</h5>
    <br />
    <p><b>Development:</b></p>
    <p>
      Initially, a function was created which took the value of the mean of the NICU and Benaron-Benitz formulae for gas
      flow
      rates less than 200 mL/min, and took the value of only Benaron-Benitz otherwise. The function displayed a
      discontinuity
      at exactly 200 mL/min as NICU predicts a non-zero FiO2 for this flow rate. The function was smoothed by
      fitting a polynomial of second degree, the coefficients of which were derived using polynomial regression. A first
      degree (linear) polynomial did not approximate the function well at all, a third
      degree polynomial showed no significant deviation from the second degree polynomial and a fourth degree polynomial
      was
      too close of a fit to the discontinuity and hence displayed behaviour that would not be expected physically.
    </p>
    <p>
      The quadratic fit did show unphysical behaviour in that it sometimes predicted a maximum FiO2 after which FiO2
      decreases with increasing flow rate. This is in contrast to the predictions made by other models, which are all
      either
      monotonically increasing or monotonically increasing up to a point at which they become constant. A consequence of
      this
      decreasing portion was that a reverse calculator for the hybrid model would return two different gas flow rate
      values
      (before and after the maximum FiO2). To avoid ambiguity, the final hybrid calculator was made single-valued by
      taking
      the form of the quadratic fit up to the maximum FiO2 reached by Benaron-Benitz and taking that value
      for all greater flow rates. This maximum was chosen as it is closest to the hypopharyngeal measurments extracted
      from <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/ppul.24441">Gonzalez et al. (2019)</a> and comes
      from a validated model.
    </p>
    <p>If selecting flow rate for the preferred output, the formula is inverted to solve for flow rate.</p>
    <p><b>Conditions:</b></p>
    <p>
      The quadratic used is only fit using flow rate values up to 2000 mL/min (what is considered the low-flow limit),
      hence that is maximum value recommended for use.
      As Finer (NICU) is used to produce this quadratic it is best if a respiratory rate is known.
    </p>
    <p>
      As made evident by the disclaimer on the calculator, this model has only been validated against one (small) data
      set (<a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/ppul.24441">Gonzalez et al. (2019)</a>), and has not
      been
      peer-reviewed, hence medical practitioners should always exercise caution if choosing to use the value given by
      this model. The peer-reviewed and validated Finer and Benaron-Benitz
      values are always displayed alongside the hybrid value for comparison.
    </p>
    </br>
    <p>
      <b>Note:</b> The Hybrid calculator uses the package regression-js to fit the polynomial under the <a
        href="https://github.com/Tom-Alexander/regression-js/blob/master/LICENSE">MIT License</a>.
    </p>
    <p xmlns:cc="http://creativecommons.org/ns#">This work is licensed under <a
        href="http://creativecommons.org/licenses/by-nc-sa/4.0/?ref=chooser-v1" target="_blank"
        rel="license noopener noreferrer" style="display:inline-block;">CC BY-NC-SA 4.0<img
          style="height:22px!important;margin-left:3px;vertical-align:text-bottom;"
          src="https://mirrors.creativecommons.org/presskit/icons/cc.svg?ref=chooser-v1"><img
          style="height:22px!important;margin-left:3px;vertical-align:text-bottom;"
          src="https://mirrors.creativecommons.org/presskit/icons/by.svg?ref=chooser-v1"><img
          style="height:22px!important;margin-left:3px;vertical-align:text-bottom;"
          src="https://mirrors.creativecommons.org/presskit/icons/nc.svg?ref=chooser-v1"><img
          style="height:22px!important;margin-left:3px;vertical-align:text-bottom;"
          src="https://mirrors.creativecommons.org/presskit/icons/sa.svg?ref=chooser-v1"></a></p>
  </div>

  <script src="https://code.jquery.com/jquery-3.5.1.slim.min.js"
    integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj"
    crossorigin="anonymous"></script>
  <script src="https://cdn.jsdelivr.net/npm/bootstrap@4.5.3/dist/js/bootstrap.bundle.min.js"
    integrity="sha384-ho+j7jyWK8fNQe+A12Hb8AhRq26LrZ/JpcUGGOn+Y7RsweNrtN/tE3MoK7ZeZDyx"
    crossorigin="anonymous"></script>
</body>

</html>