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Updated documentation to reflect respiratory changes and new mechanical ventilator validation.

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docs/Methodology/MechanicalVentilatorMethodology.md
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......@@ -8,7 +8,7 @@ Mechanical Ventilator Methodology {#MechanicalVentilatorMethodology}
The Mechanical Ventilator Model is a generic representation of a positive-pressure ventilation device and
inhaled gas/agent administration. It models a semi-closed circuit breathing system. The current implementation is limited, but the data model is designed for future expansion.
The results of this system were evaluated for pressure control - continuous mandatory ventilation (PC-CMV) and volume control - assist control (VC-AC) ventilation modes. The results show excellent correlation with the expected values.
The results of this system were evaluated for pressure control - continuous mandatory ventilation (PC-CMV), volume control - continuous mandatory ventilation (VC-CMV), and volume control - assist control (VC-AC) ventilation modes. The results show excellent correlation with the expected values.
Future work will add more ventilation modes.
@anchor ventilator-intro
......@@ -150,7 +150,7 @@ System that regulates the atmospheric/reference pressure.
@anchor ventilator-assumptions
## Assumptions and Limitations
Currently, the Mechanical Ventilator uses ideal pressure sources and one-way valves. Only setting appropriate for a PC-CMV or VC-AC modes are allowed and tested. However, the system is defined and implemented to allow for future mode expansion without data model changes.
Currently, the Mechanical Ventilator uses ideal pressure sources and one-way valves. Only setting appropriate for a PC-CMV, VC-CMV, and VC-AC modes are allowed and tested. However, the system is defined and implemented to allow for future mode expansion without data model changes.
@anchor ventilator-results
# Results and Conclusions
......@@ -197,26 +197,9 @@ A scenario that varies the VC-AC settings for assisted breathing for a patient w
<center><i>Figure 3. These plots show the successful implementation of varying Mechanical Ventilator settings with patient spontaneous breathing.</i></center><br>
@anchor ventilator-ardsvalidation
## Validation - ARDS
## Validation - Healthy vs. ARDS vs. COPD
The %Respiratory ARDS model with mild, moderate, and severe severities is extensively tested in this scenario. The patient is administered a neuromuscular blockade to prevent spontaneous breathing and ideal PIP, PEEP, and FiO2 values are set in the ventilator to maintain adequate SpO2 values. Results successfully match expected empirical data and trends, as shown in table 1. Example outputs are shown in Figure 4.
<center>
<table border="0">
<tr>
<td><img src="./plots/MechanicalVentilator/MechanicalVentilatorPressureControlledARDS_TidalVolume.jpg" width="550"></td>
<td><img src="./plots/MechanicalVentilator/MechanicalVentilatorPressureControlledARDS_OxygenSaturation.jpg" width="550"></td>
</tr>
<tr>
<td><img src="./plots/MechanicalVentilator/MechanicalVentilatorPressureControlledARDS_CarricoIndex.jpg" width="550"></td>
<td><img src="./plots/MechanicalVentilator/MechanicalVentilatorPressureControlledARDS_ShuntFraction.jpg" width="550"></td>
</tr>
<tr>
<td colspan="2"><img src="./plots/MechanicalVentilator/MechanicalVentilatorPressureControlledARDSLegend.jpg" width="1100"></td>
</tr>
</table>
</center>
<center><i>Figure 4. These plots show the successful implementation of a ventilated patient with varying ARDS severities.</i></center><br>
The %Respiratory ARDS and COPD models with mild, moderate, and severe severities is extensively tested in the scenarios shown in table 1. Each row is a separate invasive mechanical ventilation scenario that is run for several minutes to reach a new homeostatic point based on the patient's disease state and ventilator settings. The patient is administered a neuromuscular blockade to prevent spontaneous breathing for all but the VC-AC scenario. Typical/ideal ventilator setting are used based on literature @cite arnal2013feasibility @cite el2020comparison @cite acute2000ventilation and subject matter @cite chatburnSME input. Results successfully match expected empirical data and trends.
<center><br>
Table 1. Cumulative validation results for Anesthesia Machine specific conditions and actions scenarios.
......@@ -228,13 +211,17 @@ Table 1. Cumulative validation results for Anesthesia Machine specific condition
|<span class="warning"> Some deviation: correct trend and/or <30% deviation from expected </span>|
|<span class="danger"> Poor agreement: incorrect trends or >30% deviation from expected </span>|
| Segment | Notes | Action Occurrence Time (s) | Sampled Scenario Time (s) | Respiration Rate (breaths/min) | Carrico Index [PaO2/FiO2] (mmHg) | Shunt Fraction | Oxygen Saturation | Tidal Volume (mL) | Pulmonary Compliance (L/cmH2O) |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Mild ARDS (severity = 0.3) | Chronic condition | | 0 |<span class="success"> Increased @cite mortelliti2002acute </span>|<span class="success"> >200 @cite villar2013universal </span>|<span class="success"> 2%-5% @cite Levitzky2013pulmonary </span>|<span class="success"> Reduced </span>|<span class="success"> Reduced (fatigue) </span>|<span class="success"> Reduced @cite mortelliti2002acute </span>|
| Tracheal Intubation | | 30 | 60 |<span class="success"> Increased @cite mortelliti2002acute </span>|<span class="success"> >200 @cite villar2013universal </span>|<span class="success"> 2%-5% @cite Levitzky2013pulmonary </span>|<span class="success"> Reduced </span>|<span class="success"> Reduced further (artificial airway) @cite arnal2018parameters </span>|<span class="success"> Reduced further (artificial airway) @cite mortelliti2002acute @cite arnal2018parameters </span>|
| Apnea (Dyspnea severity = 1.0); Turn on P-CMV mechanical ventilator and provide supplemental oxygen | Use apnea to mimic neuromuscular blockade; Ventilator settings chosen for target tidal volume and oxygen saturation | 60 | 360 |<span class="success"> 20 (ventilator setting) </span>|<span class="success"> >200 @cite villar2013universal </span>|<span class="success"> 2%-5% @cite Levitzky2013pulmonary </span>|<span class="success"> 88%-95% @cite mortelliti2002acute (ventilator target) </span>|<span class="success"> 6 mL/kg (ideal body weight) = 450 mL @cite mortelliti2002acute (ventilator target) </span>|<span class="success"> Reduced @cite mortelliti2002acute </span>|
| Moderate ARDS (severity = 0.6); Adjust ventilator settings | Ventilator settings chosen for target tidal volume and oxygen saturation | 360 | 660 |<span class="success"> 20 (ventilator setting) </span>|<span class="success"> 100-200 @cite villar2013universal </span>|<span class="success"> >20% @cite radermacher2017fifty </span>|<span class="success"> 88%-95% @cite mortelliti2002acute (ventilator target) </span>|<span class="success"> 6 mL/kg (ideal body weight) = 450 mL @cite mortelliti2002acute (ventilator target) </span>|<span class="success"> Reduced further @cite mortelliti2002acute </span>|
| Severe ARDS (severity = 0.9); Adjust ventilator settings | Ventilator settings chosen for target tidal volume and supplemental oxygen at max (1.0 fraction O2) | 660 | 960 |<span class="success"> 20 (ventilator setting) </span>|<span class="success"> <100 @cite villar2013universal </span>|<span class="success"> >40% @cite radermacher2017fifty </span>|<span class="success"> Reduced (100% FiO2) </span>|<span class="success"> 6 mL/kg (ideal body weight) = 450 mL @cite mortelliti2002acute (ventilator target) </span>|<span class="success"> Reduced further @cite mortelliti2002acute </span>|
| Patient State | Ventilator Settings | Respiration Rate (bpm) | Inspiratory-Expiratory Ratio | Pulmonary Resistance (cmH2O-s/L) | Pulmonary Compliance (L/cmH2O) | pH | Arterial Carbon Dioxide Pressure (mmHg) | Arterial Oxygen Pressure (mmHg) | PaO2/FiO2 (mmHg) | Oxygen Saturation (%) | Pulmonary Shunt Fraction (%) | Alveolar Dead Space (L) |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Healthy | Mode: PC-CMV<br>Inspiratory Pressure Target: set empirically to achieve VT Target<br>VT Target (mL/kg): 7<br>VT Target (mL): 527<br>PEEP (cm H2O): 5<br>FiO2 (%): 30<br>Mandatory Rate (bpm): 15 <br>I:E: 0.60<br>Minute Ventilation (L/min): 7.9<br> |<span class="success"> 15 (ventilator setting) </span>|<span class="success"> 0.6 (ventilator setting) </span>|<span class="success"> 12-17 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> 20-54 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> 7.27-7.40 @cite arnal2013feasibility </span>|<span class="success"> 35-42 @cite arnal2013feasibility </span>|<span class="success"> 85-114 @cite arnal2013feasibility </span>|<span class="success"> 264-366 @cite arnal2013feasibility, @cite ferguson2012berlin </span>|<span class="success"> 96.4-98.5 @cite arnal2013feasibility, @cite kacmarek2016egan </span>|<span class="success"> 2-5 @cite Levitzky2013pulmonary, @cite radermacher2017fifty, @cite petersson2014gas </span>|<span class="success"> ~0 @cite Levitzky2013pulmonary </span>|
| Healthy | Mode: VC-CMV<br>Inspiratory Pressure Target: set empirically to achieve VT Target<br>VT Target (mL/kg): 7<br>VT Target (mL): 527<br>PEEP (cm H2O): 5<br>FiO2 (%): 30<br>Mandatory Rate (bpm): 15 <br>I:E: 0.60<br>Minute Ventilation (L/min): 7.9<br> |<span class="success"> 15 (ventilator setting) </span>|<span class="success"> 0.6 (ventilator setting) </span>|<span class="success"> 12-17 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> 20-54 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> 7.27-7.40 @cite arnal2013feasibility </span>|<span class="success"> 35-42 @cite arnal2013feasibility </span>|<span class="success"> 85-114 @cite arnal2013feasibility </span>|<span class="success"> 264-366 @cite arnal2013feasibility, @cite ferguson2012berlin </span>|<span class="success"> 96.4-98.5 @cite arnal2013feasibility, @cite kacmarek2016egan </span>|<span class="success"> 2-5 @cite Levitzky2013pulmonary, @cite radermacher2017fifty, @cite petersson2014gas </span>|<span class="success"> ~0 @cite Levitzky2013pulmonary </span>|
| Healthy | Mode: VC-AC<br>Inspiratory Pressure Target: set empirically to achieve VT Target<br>VT Target (mL/kg): 7<br>VT Target (mL): 527<br>PEEP (cm H2O): 5<br>FiO2 (%): 30<br>Mandatory Rate (bpm): 15 <br>I:E: 0.60<br>Minute Ventilation (L/min): 7.9<br> |<span class="success"> 15-21 @cite arnal2013feasibility </span>|<span class="success"> 0.4-0.8 @cite arnal2013feasibility </span>|<span class="success"> 12-17 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> 20-54 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> 7.27-7.40 @cite arnal2013feasibility </span>|<span class="success"> 35-42 @cite arnal2013feasibility </span>|<span class="success"> 85-114 @cite arnal2013feasibility </span>|<span class="success"> 264-366 @cite arnal2013feasibility, @cite ferguson2012berlin </span>|<span class="success"> 96.4-98.5 @cite arnal2013feasibility, @cite kacmarek2016egan </span>|<span class="success"> 2-5 @cite Levitzky2013pulmonary, @cite radermacher2017fifty, @cite petersson2014gas </span>|<span class="success"> ~0 @cite Levitzky2013pulmonary </span>|
| Mild ARDS (severity = 0.3) | Mode: PC-CMV<br>Inspiratory Pressure Target: set empirically to achieve VT Target<br>VT Target (mL/kg): 6<br>VT Target (mL): 452<br>PEEP (cm H2O): 11<br>FiO2 (%): 40<br>Mandatory Rate (bpm): 17<br>I:E: 0.90<br>Minute Ventilation (L/min): 7.6<br> |<span class="success"> 17 (ventilator setting) </span>|<span class="success"> 0.9 (ventilator setting) </span>|<span class="success"> No change, 10-16 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> Decrease, 20-54 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> 7.15-7.34 @cite arnal2013feasibility </span>|<span class="success"> 45-57 @cite arnal2013feasibility </span>|<span class="success"> 103-133 @cite arnal2013feasibility </span>|<span class="success"> Decrease, 200-300 @cite ferguson2012berlin </span>|<span class="success"> 98.0-99.0 @cite arnal2013feasibility, @cite kacmarek2016egan </span>|<span class="success"> Increase, >10% @cite radermacher2017fifty, @cite petersson2014gas </span>|<span class="success"> Increase @cite nuckton2002pulmonary </span>|
| Moderate ARDS (severity = 0.6) | Mode: PC-CMV<br>Inspiratory Pressure Target: set empirically to achieve VT Target<br>VT Target (mL/kg): 6<br>VT Target (mL): 452<br>PEEP (cm H2O): 11<br>FiO2 (%): 70<br>Mandatory Rate (bpm): 20<br>I:E: 0.90<br>Minute Ventilation (L/min): 9.0<br> |<span class="success"> 20 (ventilator setting) </span>|<span class="success"> 0.9 (ventilator setting) </span>|<span class="success"> No change, 10-16 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> Decrease, 20-54 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> 7.15-7.34 @cite arnal2013feasibility </span>|<span class="success"> 45-57 @cite arnal2013feasibility </span>|<span class="success"> 81-117 @cite arnal2013feasibility </span>|<span class="success"> Decrease, 100-200 @cite ferguson2012berlin </span>|<span class="success"> 95.9-98.6 @cite arnal2013feasibility, @cite kacmarek2016egan </span>|<span class="success"> Increase, >20% @cite radermacher2017fifty, @cite petersson2014gas </span>|<span class="success"> Increase @cite nuckton2002pulmonary </span>|
| Severe ARDS (severity = 0.9) | Mode: PC-CMV<br>Inspiratory Pressure Target: set empirically to achieve VT Target<br>VT Target (mL/kg): 6<br>VT Target (mL): 452<br>PEEP (cm H2O): 11<br>FiO2 (%): 100<br>Mandatory Rate (bpm): 25<br>I:E: 0.90<br>Minute Ventilation (L/min): 11.5<br> |<span class="success"> 25 (ventilator setting) </span>|<span class="success"> 0.9 (ventilator setting) </span>|<span class="success"> No change, 10-16 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> Decrease, 20-54 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> 7.15-7.34 @cite arnal2013feasibility </span>|<span class="success"> 45-57 @cite arnal2013feasibility </span>|<span class="success"> 56-83 @cite arnal2013feasibility </span>|<span class="success"> Decrease, <100 @cite ferguson2012berlin </span>|<span class="success"> 88.8-96.1 @cite arnal2013feasibility, @cite kacmarek2016egan </span>|<span class="success"> Increase, >40% @cite radermacher2017fifty, @cite petersson2014gas </span>|<span class="success"> Increase @cite nuckton2002pulmonary </span>|
| Mild COPD (severity = 0.3) | Mode: PC-CMV<br>Inspiratory Pressure Target: set empirically to achieve VT Target<br>VT Target (mL/kg): 9.0<br>VT Target (mL): 678<br>PEEP (cm H2O): 8<br>FiO2 (%): 31<br>Mandatory Rate (bpm): 12<br>I:E: 0.43<br>Minute Ventilation (L/min): 8.0<br> |<span class="success"> 12 (ventilator setting) </span>|<span class="success"> 0.43 (ventilator setting) </span>|<span class="success"> Increase, 17-26 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> Increase, 46-61 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> 7.2-7.31 @cite arnal2013feasibility </span>|<span class="success"> 44-67 @cite arnal2013feasibility </span>|<span class="success"> 77-94 @cite arnal2013feasibility </span>|<span class="success"> Decrease, 206-295 @cite ferguson2012berlin </span>|<span class="success"> 95.2-97.3 @cite arnal2013feasibility, @cite kacmarek2016egan </span>|<span class="success"> Increase @cite boerrigter2011cardiac </span>|<span class="success"> Increase @cite Levitzky2013pulmonary </span>|
| Moderate COPD (severity = 0.6) | Mode: PC-CMV<br>Inspiratory Pressure Target: set empirically to achieve VT Target<br>VT Target (mL/kg): 8.5<br>VT Target (mL): 640<br>PEEP (cm H2O): 8<br>FiO2 (%): 31<br>Mandatory Rate (bpm): 14<br>I:E: 0.43<br>Minute Ventilation (L/min): 9.0<br> |<span class="success"> 14 (ventilator setting) </span>|<span class="success"> 0.43 (ventilator setting) </span>|<span class="success"> Increase, 17-26 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> Increase, 46-61 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> 7.2-7.31 @cite arnal2013feasibility </span>|<span class="success"> 44-67 @cite arnal2013feasibility </span>|<span class="success"> 77-94 @cite arnal2013feasibility </span>|<span class="success"> Decrease, 206-295 @cite ferguson2012berlin </span>|<span class="success"> 95.2-97.3 @cite arnal2013feasibility, @cite kacmarek2016egan </span>|<span class="success"> Increase @cite boerrigter2011cardiac </span>|<span class="success"> Increase @cite Levitzky2013pulmonary </span>|
| Severe COPD (severity = 0.9) | Mode: PC-CMV<br>Inspiratory Pressure Target: set empirically to achieve VT Target<br>VT Target (mL/kg): 9.0<br>VT Target (mL): 678<br>PEEP (cm H2O): 8<br>FiO2 (%): 40<br>Mandatory Rate (bpm): 15<br>I:E: 0.43<br>Minute Ventilation (L/min): 10.2<br> |<span class="success"> 15 (ventilator setting) </span>|<span class="success"> 0.43 (ventilator setting) </span>|<span class="success"> Increase, 17-26 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> Increase, 46-61 @cite arnal2013feasibility, @cite arnal2018parameters </span>|<span class="success"> 7.2-7.31 @cite arnal2013feasibility </span>|<span class="success"> 44-67 @cite arnal2013feasibility </span>|<span class="success"> 77-94 @cite arnal2013feasibility </span>|<span class="success"> Decrease, 206-295 @cite ferguson2012berlin </span>|<span class="success"> 95.2-97.3 @cite arnal2013feasibility, @cite kacmarek2016egan </span>|<span class="success"> Increase @cite boerrigter2011cardiac </span>|<span class="success"> Increase @cite Levitzky2013pulmonary </span>|
@anchor ventilator-conclusion
## Conclusion
......
docs/Methodology/RespiratoryMethodology.md
View file @ 83f86689
......@@ -311,15 +311,16 @@ Each segment is given as a fraction of the total breath, with all summing to a v
Unless a conscious respiration action is called, all other segment fractions are set to 0. The inspiratory-expiratory ratio will change based on the driver respiration rate. The time series of the respiratory muscle pressure (<i>P<sub>mus</sub></i>) is given by @cite Fresnel2014musclePressure,
\f[{P_{mus}} = \left\{ {\begin{array}{*{20}{l}}
{{P_{\min }}\left( {1 - {e^{\frac{{{f_{v + 4{P_{0.1}}}}}}{{10}}t}}} \right),}&{0 < t \le {t_1}}\\
{{P_{\min }} \cdot \sin \left( {\frac{\pi }{2} \cdot \frac{t}{{{t_1}}}} \right),}&{0 < t \le {t_1}}\\
{{P_{\min }},}&{{t_1} < t \le {t_2}}\\
{{P_{\min }}\left( {{e^{ - \frac{{{f_{v + \frac{{{P_{0.1}}}}{2}}}}}{{10}}t}}} \right),}&{{t_2} < t \le {t_3}}\\
{{P_{\min }} \cdot \sin \left( {\frac{\pi }{2} \cdot \frac{{t + {t_3} - 2{t_2}}}{{{t_3} - {t_2}}}} \right),}&{{t_2} < t \le {t_3}}\\
{0,}&{{t_3} < t \le {t_4}}\\
{{P_{max}}\left( {1 - {e^{ - \frac{{{f_{v + \frac{{{P_{0.1}}}}{2}}}}}{{10}}t}}} \right),}&{{t_4} < t \le {t_5}}\\
{{P_{max}} \cdot \sin \left( {\frac{\pi }{2} \cdot \frac{{t - {t_4}}}{{{t_5} - {t_4}}}} \right),}&{{t_4} < t \le {t_5}}\\
{{P_{max}},}&{{t_5} < t \le {t_6}}\\
{{P_{max}}\left( {{e^{\frac{{{f_{v + 4{P_{0.1}}}}}}{{10}}t}}} \right),}&{{t_6} < t \le {t_7}}\\
{{P_{max}} \cdot \sin \left( {\frac{\pi }{2} \cdot \frac{{t + {t_7} - 2{t_6}}}{{{t_7} - {t_6}}}} \right),}&{{t_6} < t \le {t_7}}\\
{0,}&{{t_7} < t \le {t_{\max }}}
\end{array}} \right.\f]
<center>
<i>Equation 8.</i>
</center><br>
......@@ -1067,7 +1068,7 @@ Insults and Interventions
Disease states are applied to the simulated patient by modifying various parameters. Chronic conditions stabilize to a new homeostatic point before the simulation begins. Pulse simulates both restrictive and obstructive diseases of varying severities with different continuous function mappings. Table 2 shows parameter settings for representative conditions and severities based on trends and values determined from literature @cite brunner2019lung @cite arnal2018parameters @cite harris2005pressure @cite aguirre2018lung @cite arndt1995linear @cite bikker2008end @cite brunner2012pulmonary @cite ibanez1982normal. Most respiratory-specific pathophysiology is applied as parameter multipliers (y) determined by a severity (x) setting between 0 and 1, with the following exponential or linear functions:
\f[y = {10^{\ln \left( {x\frac{b}{a}} \right) + \ln \left( a \right)}}\f]
\f[y = {10^{\log \left( {x\frac{b}{a}} \right) + \log \left( a \right)}}\f]
<center>
<i>Equation 39.</i>
</center><br>
......@@ -1108,15 +1109,15 @@ When positive pressure ventilation is applied (i.e., mechanical ventilator or an
<th>Moderate</th>
<th>Severe</th>
</tr>
<tr><td>Alveolar Dead Space (L)</td><td>Respiratory</td><td>0</td><td>0</td><td>N/A</td><td>0</td><td>0</td><td>0</td><td>Linear Growth</td><td>0.6</td><td>1.2</td><td>1.8</td></tr>
<tr><td>Airway Resistance (cmH20-s/L)</td><td>Respiratory</td><td>1.125</td><td>9</td><td>N/A</td><td>1.125</td><td>1.125</td><td>1.125</td><td>N/A</td><td>1.125</td><td>1.125</td><td>1.125</td></tr>
<tr><td>Bronchi Resistance (cmH20-s/L)</td><td>Respiratory</td><td>0.45</td><td>0.45</td><td>N/A</td><td>0.45</td><td>0.45</td><td>0.45</td><td>Exponential Growth</td><td>1.74</td><td>6.7</td><td>25.8</td></tr>
<tr><td>Lung Compliance (L/cmH2O)</td><td>Respiratory</td><td>0.1</td><td>0.04</td><td>Linear Decay</td><td>0.082</td><td>0.064</td><td>0.046</td><td>Linear Growth</td><td>0.13</td><td>0.16</td><td>0.19</td></tr>
<tr><td>Inspiratory-Expiratory Ratio</td><td>Respiratory</td><td>0.5</td><td>0.5</td><td>Exponential Growth</td><td>1.1</td><td>2.6</td><td>12.1</td><td>Linear Decay</td><td>0.3</td><td>0.15</td><td>0.03</td></tr>
<tr><td>Diffusion Surface Area (m^2)</td><td>Respiratory</td><td>68.3</td><td>68.3</td><td>Exponential Decay</td><td>34.3</td><td>17.2</td><td>8.6</td><td>Exponential Decay</td><td>34.3</td><td>17.2</td><td>8.6</td></tr>
<tr><td>Pulmonary Capillary Resistance (mmHg-s/mL)</td><td>Cardiovascular</td><td>0.062</td><td>0.062</td><td>N/A</td><td>0.062</td><td>0.062</td><td>0.062</td><td>Linear Growth</td><td>0.094</td><td>0.126</td><td>0.157</td></tr>
<tr><td>Pulmonary Shunt Resistance (mmHg-s/mL)</td><td>Cardiovascular</td><td>8.9</td><td>8.9</td><td>Exponential Decay</td><td>2.23</td><td>0.56</td><td>0.14</td><td>N/A</td><td>8.9</td><td>8.9</td><td>8.9</td></tr>
<tr><td>Fatigue Factor</td><td>Respiratory</td><td>1</td><td>1</td><td>Linear Decay</td><td>0.76</td><td>0.52</td><td>0.28</td><td>Linear Decay</td><td>0.76</td><td>0.52</td><td>0.28</td></tr>
<tr><td>Alveolar Dead Space (L)</td><td>Respiratory</td><td>0</td><td>0</td><td>Polynomial Growth</td><td>0</td><td>0.03</td><td>0.15</td><td>Linear Growth</td><td>0.3</td><td>0.6</td><td>0.9</td></tr>
<tr><td>Airway Resistance (cmH20-s/L)</td><td>Respiratory</td><td>1.125</td><td>12.375</td><td>N/A</td><td>1.125</td><td>1.125</td><td>1.125</td><td>N/A</td><td>1.125</td><td>1.125</td><td>1.125</td></tr>
<tr><td>Bronchi Resistance (cmH20-s/L)</td><td>Respiratory</td><td>0.45</td><td>0.45</td><td>N/A</td><td>0.45</td><td>0.45</td><td>0.45</td><td>Linear Growth</td><td>8.5</td><td>1.7</td><td>2.4</td></tr>
<tr><td>Lung Compliance (L/cmH2O)</td><td>Respiratory</td><td>0.1</td><td>0.04</td><td>Exponential Decay</td><td>0.07</td><td>0.05</td><td>0.04</td><td>Exponential Growth</td><td>0.1</td><td>0.11</td><td>0.14</td></tr>
<tr><td>Inspiratory-Expiratory Ratio</td><td>Respiratory</td><td>0.5</td><td>0.5</td><td>Linear Growth</td><td>0.7</td><td>1.1</td><td>1.5</td><td>Linear Decay</td><td>0.35</td><td>0.22</td><td>0.12</td></tr>
<tr><td>Diffusion Surface Area (m^2)</td><td>Respiratory</td><td>68</td><td>68</td><td>Exponential Decay</td><td>34</td><td>17</td><td>9</td><td>Exponential Decay</td><td>39</td><td>22</td><td>12</td></tr>
<tr><td>Pulmonary Capillary Resistance (mmHg-s/mL)</td><td>Cardiovascular</td><td>0.062</td><td>0.062</td><td>N/A</td><td>0.062</td><td>0.062</td><td>0.062</td><td>Linear Growth</td><td>0.16</td><td>0.25</td><td>0.35</td></tr>
<tr><td>Pulmonary Shunt Resistance (mmHg-s/mL)</td><td>Cardiovascular</td><td>8.9</td><td>8.9</td><td>Exponential Decay</td><td>2.75</td><td>0.81</td><td>0.25</td><td>N/A</td><td>8.9</td><td>8.9</td><td>8.9</td></tr>
<tr><td>Fatigue Factor</td><td>Respiratory</td><td>1</td><td>1</td><td>Linear Decay</td><td>0.76</td><td>0.52</td><td>0.28</td><td>Linear Decay</td><td>0.87</td><td>0.76</td><td>0.64</td></tr>
</table>
Modifications to respiratory circuit resistances and compliances can further be examined and validated through volume-flow curves, like those created during spirometry testing. Figure 17 shows results from a simulated pulmonary function test with the standard patient healthy and with moderate ARDS and COPD.
......
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