The Multi Split Ventilator System: Design and Function of a Regulated, Shared Ventilator System

2020 ◽  
Author(s):  
Donald Gaucher ◽  
A Zachary Trimble ◽  
Brennan Yamamoto ◽  
Scott Miller ◽  
John Vossler ◽  
...  
Keyword(s):  
Patient Safety ◽  
Tidal Volume ◽  
Minute Ventilation ◽  
Simulated Patient ◽  
Simulated Patients ◽  
Laboratory Assessment ◽  
Safety Consideration ◽  
Clinical Changes ◽  
And Function ◽  
Multiple Patients

Abstract The objective of this paper is to describe the design and function of the Multi Split Ventilator system (MSVS); an airflow apparatus that enables physicians to provide individualized, isolated ventilation to up to four patients using a single ventilator. Method: The study design is laboratory assessment of the ability of the MSVS to decouple the pressures and resulting tidal volumes between patient limbs in response to adverse extubation (disconnection) or endotracheal tube occlusion of one of the patients in the system. We compare the airflow decoupling of the MSVS against an existing unregulated split ventilator system (USVS) design over eight prototypical patient pairs. Simulated patient prototypes of varying size, minute ventilation requirement, and PEEP requirement were employed. Result: Respiratory support was developed for varying simulated patient pairs using the MSVS and a USVS. The results demonstrate that patients supported with the MSVS showed significantly smaller changes to tidal volume and PEEP after extubation events, and tidal volume after occlusion events. Conclusion: It was found that the MSVS as a regulated, shared ventilator system effectively buffered simulated patients from clinical changes occurring to another patient connected to the split ventilator. This decoupling ability resulted in significantly smaller changes in delivered support when compared to existing USVS designs, which is an important patient safety consideration if deciding to support multiple patients with a single ventilator.

scholarly journals Adaptive split ventilator system enables parallel ventilation, individual monitoring and ventilation pressures control for each lung simulators

2020 ◽  
Author(s):  
Shahroor Sarit Hadar ◽  
Sarouf Yarden ◽  
Oz-Ari Leav ◽  
M Gilad ◽  
K. Joseph ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Minute Ventilation ◽  
Pressure Sensors ◽  
Peak Inspiratory Pressure ◽  
Safety Monitoring ◽  
Simulated Patient ◽  
Air Leak ◽  
Lung Simulator ◽  
Clinical Scenarios ◽  
Number Of Patients

AbstractObjectiveIn mass crisis setting such as the COVID-19 pandemic, the number of patients requiring invasive ventilation may exceed the number of available ventilators. This challenge led to the concept of splitting ventilator between several patients, which aroused interest as well as a strong opposition from multiple professional societies (The joint statement)1.Establishment of a safe ventilator splitting setup which enables monitoring and control of each ventilated patient would be a desirable ability. Achieving independency between the Co-vent patients would enable effective coping with different individual clinical scenarios and broaden the pairing possibilities of patients connected to a single ventilator. We conducted an experiment to determine if our designed setup achieves these goals.MethodsWe utilized a double two limbed modified ventilator circuits which were connected to dual lung simulators. Adding readily available pressure sensors (transducers), PEEP valves, flow control valves, one-way (check) valves and HME filters made the circuit safe enough and suitable for our goals. We first examined a single lung simulator establishing the baseline set parameters, while monitoring ventilator measures as Tidal Volume. The initial ventilator setting we chose was a controlled mandatory ventilation mode with a PIP (peak inspiratory pressure) of 25cmH2O, PEEP (Positive End Expiratory Pressure) of 5 cmH2O. In pressure control set at 20 cmH2O, the recorded mean TV(tidal volume) was 1000 mL (approximately 500 mL/lung simulator) with an average MV(minute ventilation) of 13 L/min (or 6.5 L/min/lung simulator). After examining the system with the dual modified circuits attached, and obtaining all the ventilation parameters, we simulated several clinical scenarios. We simulated clinical events such as: partial or full obstruction, disconnection, air leak and compliance differentials, which occur frequently on a ventilation course. Thus, it is a paramount system demand to keep undisturbed ventilation to the Co-vent patient A, while being challenged by patient B.ResultsThe adaptive split ventilator setup yields increased safety, monitoring, and controls ventilation parameters successfully for each connected simulated patient (using lung simulators).It also enables coping with several common clinical scenarios on a ventilation course, by allowing the care provider to control PIP and PEEP of each Co-Vent patient.ConclusionIn a mass crisis setting, when there is a shortage of ventilators supply, and as a last resort, this setup can be a viable option to act upon. This experiment demonstrates the ability of the split ventilator to ventilate dual lung simulators with increased safety, monitoring and ventilation pressures control of each simulated patient. This split ventilator kept supporting a simulated patient with undisturbed parameters while the CO-vent patient was simulated to be disconnected, having an air leak, or exhibiting lung compliance deterioration. To the best of our knowledge, this is the first time a split ventilator setup demonstrates these capabilities. Our pilot experiment suggests a significant potential of expanding the ventilator support resources, and is especially relevant during COVID-19 outbreak. Since this setup has not been used in a clinical setting yet, further research should be conducted to explore the safety limits and the capabilities of this model.

The Multi Split Ventilator System: Performance Testing of Respiratory Support Shared by Multiple Patients

2022 ◽  
Author(s):  
Donald Gaucher ◽  
A Zachary Trimble ◽  
Brennan Yamamoto ◽  
Ebrahim Seidi ◽  
Scott Miller ◽  
...  
Keyword(s):  
Adverse Events ◽  
Endotracheal Tube ◽  
System Performance ◽  
Minute Ventilation ◽  
Ventilatory Support ◽  
Performance Testing ◽  
Simulated Patients ◽  
Performance Tests ◽  
Feasible Option ◽  
Multiple Patients

Abstract Ventilator sharing has been proposed as a method of increasing ventilator capacity during instances of critical shortage. We sought to assess the ability of a regulated, shared ventilator system (Multi Split Ventilator System, MSVS) to individualize support to multiple simulated patients using one ventilator. We employed simulated patients of varying size, compliance, minute ventilation requirement, and PEEP requirement. Performance tests were performed to assess the ability of the QSVS, versus control, to achieve individualized respiratory goals to clinically disparate patients sharing a single ventilator following ARDSNet guidelines. Resilience tests measured the effects of simulated adverse events occurring to one patient on another patient sharing a single ventilator. The QSVS met individual oxygenation and ventilation requirements for multiple simulated patients with a tolerance similar to a single ventilator. Abrupt endotracheal tube occlusion or extubation occurring to one patient resulted in modest, clinically tolerable changes in ventilation parameters for the remaining patients. The QSVS is a regulated, shared ventilator system capable of individualizing ventilatory support to clinically dissimilar simulated patients. It is also resilient to common adverse events. The QSVS represents a feasible option to ventilate multiple patients during a severe ventilator shortage.

scholarly journals Effect of respiratory effort on target minute ventilation during Adaptive Support Ventilation.

2021 ◽  
Vol 2 (2) ◽  
pp. 53-58
Author(s):  
Marissa Su ◽  
ehab daoud
Keyword(s):  
Mechanical Ventilation ◽  
Tidal Volume ◽  
Respiratory Rate ◽  
Minute Ventilation ◽  
Work Of Breathing ◽  
Simulated Patients ◽  
Respiratory Effort ◽  
Adaptive Support Ventilation ◽  
Support Ventilation ◽  
Adaptive Support

Background: Adaptive support ventilation (ASV) is an intelligent mode of mechanical ventilation protocol which uses a closed-loop control between breaths. The algorithm states that for a given level of alveolar ventilation, there is a particular respiratory rate and tidal volume which achieve a lower work of breathing. The mode allows the clinician to set a desired minute ventilation percentage (MV%) while the ventilator automatically selects the target ventilatory pattern base on these inputs and feedback from the ventilator monitoring system. The goal is to minimize the work of breathing and reduce complications by allowing the ventilator to adjust the breath delivery taking into account the patient’s respiratory mechanics (Resistance, and Compliance). In this study we examine the effect of patients’ respiratory effort on target tidal volume (VT) and Minute Ventilation (V̇e) during ASV using breathing simulator. Methods: A bench study was performed by using the ASL 5000 breathing simulator to compare the target ventilator to actual VT and V̇e value in simulated patients with various level of respiratory effort during ASV on the Hamilton G5 ventilator. The clinical scenario involves simulated adult male with IBW 70kg and normal lung mechanics: respiratory compliance of 70 mL/cm H2O, and airway resistance of 9 cm H2O/L/s. Simulated patients were subjected to five different level of muscle pressure (Pmus): 0 (Passive), -5, -10, -15, -25 (Active) cm H2O at a set respiratory rate of 10 (below targeted VT) set at three different levels of minute ventilation goals: 100%, 200%, and 300%, with a PEEP of 5 cm H2O. Fifty breaths were analyzed in every experiment. Means and standard deviations (SD) of variables were calculated. One way analysis of variants was done to compare the values. Pearson correlation coefficient test was used to calculate the correlation between the respiratory effort and the VT, V̇e, and peak inspiratory pressure (PIP). Results: The targeted VT and V̇e were not significant in the passive patient when no effort was present, however were significantly higher in the active states at all levels of Pmus on the 100%, 200% and the 300 MV%. The VT and V̇e increase correlated with the muscle effort in the 100 and 200 MV% but did not in the 300%. Conclusions: Higher inspiratory efforts resulted in significantly higher VT and V̇e than targeted ones. Estimating patients’ effort is important during setting ASV. Keywords: Mechanical ventilation, ASV, InteliVent, Pmus, tidal volume, percent minute ventilation

Ventilatory response to hypoxia in unanesthetized newborn kittens

1988 ◽  
Vol 64 (6) ◽  
pp. 2544-2551 ◽  
Author(s):  
H. Rigatto ◽  
C. Wiebe ◽  
C. Rigatto ◽  
D. S. Lee ◽  
D. Cates
Keyword(s):  
Tidal Volume ◽  
Chest Wall ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Respiratory Frequency ◽  
Quiet Sleep ◽  
Newborn Kitten ◽  
Peripheral Mechanism ◽  
Flow Through ◽  
Ventilatory Response To Hypoxia

We studied the ventilatory response to hypoxia in 11 unanesthetized newborn kittens (n = 54) between 2 and 36 days of age by use of a flow-through system. During quiet sleep, with a decrease in inspired O2 fraction from 21 to 10%, minute ventilation increased from 0.828 +/- 0.029 to 1.166 +/- 0.047 l.min-1.kg-1 (P less than 0.001) and then decreased to 0.929 +/- 0.043 by 10 min of hypoxia. The late decrease in ventilation during hypoxia was related to a decrease in tidal volume (P less than 0.001). Respiratory frequency increased from 47 +/- 1 to 56 +/- 2 breaths/min, and integrated diaphragmatic activity increased from 14.9 +/- 0.9 to 20.2 +/- 1.4 arbitrary units; both remained elevated during hypoxia (P less than 0.001). Younger kittens (less than 10 days) had a greater decrease in ventilation than older kittens. These results suggest that the late decrease in ventilation during hypoxia in the newborn kitten is not central but is due to a peripheral mechanism located in the lungs or respiratory pump and affecting tidal volume primarily. We speculate that either pulmonary bronchoconstriction or mechanical uncoupling of diaphragm and chest wall may be involved.

Decreased Carbon Dioxide Sensitivity in Infants of Substance-Abusing Mothers

PEDIATRICS ◽  
1995 ◽  
Vol 95 (6) ◽  
pp. 864-867
Author(s):  
Janet G. Wingkun ◽  
Janet S. Knisely ◽  
Sidney H. Schnoll ◽  
Gary R. Gutcher
Keyword(s):  
Carbon Dioxide ◽  
Tidal Volume ◽  
Minute Ventilation ◽  
Demographic Data ◽  
Substance Abusing ◽  
Quiet Sleep ◽  
Co2 Level ◽  
The Difference ◽  
End Tidal ◽  
Drug Free

Objective. To determine whether there is a demonstrable abnormality in control of breathing in infants of substance-abusing mothers during the first few days of life. Methods. We enrolled 12 drug-free control infants and 12 infants of substance abusing mothers (ISAMs). These infants experienced otherwise uncomplicated term pregnancies and deliveries. The infants were assigned to a group based on the results of maternal histories and maternal and infant urine toxicology screens. Studies were performed during quiet sleep during the first few days of life. We measured heart rate, oxygen saturations via a pulse oximeter, end-tidal carbon dioxide (ET-CO2) level, respiratory rate, tidal volume, and airflow. The chemoreceptor response was assessed by measuring minute ventilation and the ET-CO2 level after 5 minutes of breathing either room air or 4% carbon dioxide. Results. The gestational ages by obstetrical dating and examination of the infants were not different, although birth weights and birth lengths were lower in the group of ISAMs. Other demographic data were not different, and there were no differences in the infants' median ages at the time of study or in maternal use of tobacco and alcohol. The two groups had comparable baseline (room air) ET-CO2 levels, respiratory rates, tidal volumes, and minute ventilation. When compared with the group of ISAMs, the drug-free group had markedly increased tidal volume and minute ventilation on exposure to 4% carbon dioxide. These increases accounted for the difference in sensitivity to carbon dioxide, calculated as the change in minute ventilation per unit change in ET-CO2 (milliliters per kg/min per mm Hg). The sensitivity to carbon dioxide of control infants was 48.66 ± 7.14 (mean ± SE), whereas that of ISAMs was 16.28 ± 3.14. Conclusions. These data suggest that ISAMs are relatively insensitive to challenge by carbon dioxide during the first few days of life. We speculate that this reflects an impairment of the chemoreceptor response.

scholarly journals Impact of cervical spinal cord contusion on the breathing pattern across the sleep-wake cycle in the rat

2019 ◽  
Vol 126 (1) ◽  
pp. 111-123 ◽  
Author(s):  
Kun-Ze Lee
Keyword(s):  
Spinal Cord ◽  
Tidal Volume ◽  
Spinal Injury ◽  
Cervical Spinal Cord ◽  
Minute Ventilation ◽  
Respiratory Frequency ◽  
Breathing Patterns ◽  
Cord Injury ◽  
Spinal Contusion ◽  
Cervical Spinal Injury

The present study was designed to investigate breathing patterns across the sleep-wake state following a high cervical spinal injury in rats. The breathing patterns (e.g., respiratory frequency, tidal volume, and minute ventilation), neck electromyogram, and electroencephalography of unanesthetized adult male rats were measured at the acute (i.e., 1 day), subchronic (i.e., 2 wk), and/or chronic (i.e., 6 wk) injured stages after unilateral contusion of the second cervical spinal cord. Cervical spinal cord injury caused a long-term reduction in the tidal volume but did not influence the sleep-wake cycle duration. The minute ventilation during sleep was usually lower than that during the wake period in uninjured animals due to a decrease in respiratory frequency. However, this sleep-induced reduction in respiratory frequency was not observed in contused animals at the acute injured stage. By contrast, the tidal volume was significantly lower during sleep in contused animals but not uninjured animals from the acute to the chronic injured stage. Moreover, the frequency of sigh and postsigh apnea was elevated in acutely contused animals. These results indicated that high cervical spinal contusion is associated with exacerbated sleep-induced attenuation of the tidal volume and higher occurrence of sleep apnea, which may be detrimental to respiratory functional recovery after cervical spinal cord injury. NEW & NOTEWORTHY Cervical spinal injury is usually associated with sleep-disordered breathing. The present study investigated breathing patterns across sleep-wake state following cervical spinal injury in the rat. Unilateral cervical spinal contusion significantly impacted sleep-induced alteration of breathing patterns, showing a blunted frequency response and exacerbated attenuated tidal volume and occurrence of sleep apnea. The result enables us to investigate effects of cervical spinal injury on the pathogenesis of sleep-disordered breathing and evaluate potential therapies to improve respiration.

Effects of nasal positive-pressure hyperventilation on the glottis in normal awake subjects

1995 ◽  
Vol 79 (1) ◽  
pp. 176-185 ◽  
Author(s):  
V. Jounieaux ◽  
G. Aubert ◽  
M. Dury ◽  
P. Delguste ◽  
D. O. Rodenstein
Keyword(s):  
Tidal Volume ◽  
Positive Pressure Ventilation ◽  
Anterior Commissure ◽  
Minute Ventilation ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Vocal Cords ◽  
Diaphragmatic Muscle ◽  
Inspiratory Resistance ◽  
Cyclic Changes

We have recently observed obstructive apneas during nasal intermittent positive-pressure ventilation (nIPPV) and suggested that they were due to hypocapnia-induced glottic closure. To confirm this hypothesis, we studied seven healthy subjects and submitted them to nIPPV while their glottis was continuously monitored through a fiber-optic bronchoscope. During wakefulness, we measured breath by breath the widest inspiratory angle formed by the vocal cords at the anterior commissure along with several other indexes. Mechanical ventilation was progressively increased up to 30 l/min. In the absence of diaphragmatic activity, increases in delivered minute ventilation resulted in progressive narrowing of the vocal cords, with an increase in inspiratory resistance and a progressive reduction in the percentage of the delivered tidal volume effectively reaching the lungs. Adding CO2 to the inspired gas led to partial widening of the glottis in two of three subjects. Moreover, activation of the diaphragmatic muscle was always associated with a significant inspiratory abduction of the vocal cords. Sporadically, complete adduction of the vocal cords was directly responsible for obstructive laryngeal apneas and cyclic changes in the glottic aperture resulted in waxing and waning of tidal volume. We conclude that in awake humans passive ventilation with nIPPV results in vocal cord adduction that depends partly on hypocapnia, but our results suggest that other factors may also influence glottic width.

Respiratory and abdominal muscle responses to expiratory threshold loading in cystic fibrosis

1992 ◽  
Vol 72 (3) ◽  
pp. 842-850 ◽  
Author(s):  
F. Cerny ◽  
L. Armitage ◽  
J. A. Hirsch ◽  
B. Bishop
Keyword(s):  
Cystic Fibrosis ◽  
Tidal Volume ◽  
Body Position ◽  
Minute Ventilation ◽  
Abdominal Muscle ◽  
Abdominal Muscles ◽  
Breathing Frequency ◽  
Control Subjects ◽  
Lung Dysfunction ◽  
Muscle Responses

We hypothesized that the hyperinflation and pulmonary dysfunction of cystic fibrosis (CF) would distort feedback and therefore alter the abdominal muscle response to graded expiratory threshold loads (ETLs). We compared the respiratory and abdominal muscle responses with graded ETLs of seven CF patients with severe lung dysfunction with those of matched healthy control subjects in the supine and 60 degrees head-up positions. Breathing frequency, tidal volume, and ventilatory timing were determined from inspiratory flow recordings. Abdominal electromyograms (EMGs) were detected with surface electrodes placed unilaterally over the external and internal oblique and the rectus abdominis muscles. Thresholds, times of onset, and durations of phasic abdominal activity were determined from raw EMGs; peak amplitudes were determined from integrated EMGs. Graded ETLs were imposed by submerging a tube from the expiratory port of the breathing valve into a column of water at depths of 0–25 cmH2O. We found that breathing frequency, tidal volume, and expired minute ventilation were higher in CF patients than in control subjects during low ETLs; a change in body position did not alter these ventilatory responses in the CF patients but did in the control subjects. All CF patients, but none of the control subjects, had tonic abdominal activity while supine. CF patients recruited abdominal muscles at lower loads, earlier in the respiratory cycle, and to a higher recruitment level in both positions than the control subjects, but burst duration of phasic activity was not different between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Split ventilation with pressure regulators for patient-specific tidal volumes

2020 ◽  
Author(s):  
Lakshminarayan “Ram” Srinivasan ◽  
Chris A. Rishel ◽  
Barrett J. Larson ◽  
Juhwan Yoo ◽  
Ned M. Shelton
Keyword(s):  
Tidal Volume ◽  
Gas Flow ◽  
Patient Management ◽  
Patient Specific ◽  
Resource Constrained ◽  
Mechanical Ventilators ◽  
Pressure Regulator ◽  
Safety Testing ◽  
Progression Of Disease ◽  
Multiple Patients

AbstractAs a measure of last resort during the COVID-19 pandemic, single mechanical ventilators have been repurposed to support multiple patients. In existing split-ventilator configurations using FDA-approved tubing adaptors, each patient receives the same inspiratory pressure, requiring careful matching of patients to avoid barotrauma. Progression of disease may cause tidal volumes to diverge from desired targets, and routine interventions (eg. suctioning) in one patient may adversely affect other patients. To overcome these limitations, we demonstrate a split-ventilator configuration that enables individualized patient management by incorporating a commonly available pressure regulator used for gas appliances. We validate this method by achieving various combinations of tidal volume in each of two synthetic lungs using a standard ventilator machine in combination with two gas flow analyzers. With further safety testing and instrumentation, pressure regulators may represent a viable path to substantially augment the capacity for ventilation in resource-constrained settings.

Response to Acute Hypercapnia in the Parents of Victims of Sudden Infant Death Syndrome

PEDIATRICS ◽  
1984 ◽  
Vol 73 (5) ◽  
pp. 652-655
Author(s):  
Jonathan M. Couriel ◽  
Anthony Olinsky
Keyword(s):  
Tidal Volume ◽  
Sudden Infant Death Syndrome ◽  
Infant Death ◽  
Cycle Time ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Sudden Infant Death ◽  
Respiratory Cycle ◽  
Sudden Infant ◽  
Inspiratory Time

The ventilatory response to acute hypercapnia was studied in 68 parents of victims of sudden infant death syndrome and 56 control subjects. Tidal volume, inspiratory time, and total respiratory cycle time were measured before and immediately after a vital capacity breath of 13% CO2 in oxygen. Instantaneous minute ventilation, mean inspiratory flow (tidal volume/inspiratory time), and respiratory timing (inspiratory time/total respiratory cycle time) were calculated. Both groups of subjects showed a marked increase in tidal volume (48.4% ± 26.5%), instantaneous minute ventilation (56% ± 35%), and tidal volume/inspiratory time (56.8% ± 33.5%) after inhalation of the test gas, with little change in inspiratory time/total respiratory cycle time. There were no significant differences between the two groups for ventilation before or after inhalation of the test gas. The ventilatory response to acute hypercapnia is mediated by the peripheral chemoreceptors. These results suggest that an inherited abnormality of peripheral chemoreceptor function is unlikely to be a factor leading to sudden infant death syndrome.

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