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Qi Q, Yu M, Ge J, Li C, Zhang G, Chen F. A combined impedance compensation strategy applied to external automatic defibrillators. BIOMED ENG-BIOMED TE 2023; 68:651-665. [PMID: 37350466 DOI: 10.1515/bmt-2022-0185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/07/2023] [Indexed: 06/24/2023]
Abstract
Transthoracic impedance is one of the key factors affecting the success of defibrillation. Impedance compensation technique is used to adjust defibrillation parameters according to the transthoracic impedance of the defibrillator. In this paper, a combined impedance compensation strategy is proposed to address the shortcomings of existing compensation strategies. In order to evaluate the performance of the combined compensation strategy, this paper uses the prototype as the experimental machine, and uses two AED with representative impedance compensation strategies as the control machine, and the simulated defibrillation method is used for comparative testing. The results show that the combined impedance compensation has a more steadier distribution over the defibrillation energy and current: compared with the energy-based impedance compensation strategy, this strategy can significantly reduce the peak current (25 Ω: 27.8 vs. 54.7 A; 50 Ω: 20.7 vs. 32.3 A) and average current (25 Ω: 24.8 vs. 37.5 A) of defibrillation at low impedance, and compared with the current impedance compensation strategy, it can significantly reduce the defibrillation energy (150 Ω: 8.6 vs. 1.7 %, 175 Ω: 15.6 vs. 4.9 %, 200 Ω: 21.9 vs. 8.5 %) at high impedance. Impedance compensation is more precise and the current passing during defibrillation is steadier.
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Affiliation(s)
- Qi Qi
- Unit for Drug and Instrument Supervision and Inspection of Wuxi Joint Logistic Support Center, PLA, Nanjing, China
| | - Ming Yu
- Medical Support Technology Research Department,Systems Engineering Institute, Academy of Military Sciences, PLA, Tianjin, China
| | - Jianhui Ge
- Unit for Drug and Instrument Supervision and Inspection of Wuxi Joint Logistic Support Center, PLA, Nanjing, China
| | - Chuanjun Li
- Unit for Drug and Instrument Supervision and Inspection of Wuxi Joint Logistic Support Center, PLA, Nanjing, China
| | - Guang Zhang
- Medical Support Technology Research Department,Systems Engineering Institute, Academy of Military Sciences, PLA, Tianjin, China
| | - Feng Chen
- Medical Support Technology Research Department,Systems Engineering Institute, Academy of Military Sciences, PLA, Tianjin, China
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Idris AH, Aramendi Ecenarro E, Leroux B, Jaureguibeitia X, Yang BY, Shaver S, Chang MP, Rea T, Kudenchuk P, Christenson J, Vaillancourt C, Callaway C, Salcido D, Carson J, Blackwood J, Wang HE. Bag-Valve-Mask Ventilation and Survival From Out-of-Hospital Cardiac Arrest: A Multicenter Study. Circulation 2023; 148:1847-1856. [PMID: 37952192 PMCID: PMC10840971 DOI: 10.1161/circulationaha.123.065561] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 08/28/2023] [Indexed: 11/14/2023]
Abstract
BACKGROUND Few studies have measured ventilation during early cardiopulmonary resuscitation (CPR) before advanced airway placement. Resuscitation guidelines recommend pauses after every 30 chest compressions to deliver ventilations. The effectiveness of bag-valve-mask ventilation delivered during the pause in chest compressions is unknown. We sought to determine: (1) the incidence of lung inflation with bag-valve-mask ventilation during 30:2 CPR; and (2) the association of ventilation with outcomes after out-of-hospital cardiac arrest. METHODS We studied patients with out-of-hospital cardiac arrest from 6 sites of the Resuscitation Outcomes Consortium CCC study (Trial of Continuous Compressions versus Standard CPR in Patients with Out-of-Hospital Cardiac Arrest). We analyzed patients assigned to the 30:2 CPR arm with ≥2 minutes of thoracic bioimpedance signal recorded with a cardiac defibrillator/monitor. Detectable ventilation waveforms were defined as having a bioimpedance amplitude ≥0.5 Ω (corresponding to ≥250 mL VT) and a duration ≥1 s. We defined a chest compression pause as a 3- to 15-s break in chest compressions. We compared the incidence of ventilation and outcomes in 2 groups: patients with ventilation waveforms in <50% of pauses (group 1) versus those with waveforms in ≥50% of pauses (group 2). RESULTS Among 1976 patients, the mean age was 65 years; 66% were male. From the start of chest compressions until advanced airway placement, mean±SD duration of 30:2 CPR was 9.8±4.9 minutes. During this period, we identified 26 861 pauses in chest compressions; 60% of patients had ventilation waveforms in <50% of pauses (group 1, n=1177), and 40% had waveforms in ≥50% of pauses (group 2, n=799). Group 1 had a median of 12 pauses and 2 ventilations per patient versus group 2, which had 12 pauses and 12 ventilations per patient. Group 2 had higher rates of prehospital return of spontaneous circulation (40.7% versus 25.2%; P<0.0001), survival to hospital discharge (13.5% versus 4.1%; P<0.0001), and survival with favorable neurological outcome (10.6% versus 2.4%; P<0.0001). These associations persisted after adjustment for confounders. CONCLUSIONS In this study, lung inflation occurred infrequently with bag-valve-mask ventilation during 30:2 CPR. Lung inflation in ≥50% of pauses was associated with improved return of spontaneous circulation, survival, and survival with favorable neurological outcome.
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Affiliation(s)
- Ahamed H Idris
- Department of Emergency Medicine, University of Texas Southwestern Medical Center, Dallas (A.H.I, B.Y.Y., S.S., M.P.C.)
| | | | - Brian Leroux
- Department of Biostatistics (B.L., J.C.), University of Washington, Seattle
| | - Xabier Jaureguibeitia
- Department of Communications Engineering, University of the Basque Country, Bilbao, Spain (E.A.E., X.J.)
| | - Betty Y Yang
- Department of Emergency Medicine, University of Texas Southwestern Medical Center, Dallas (A.H.I, B.Y.Y., S.S., M.P.C.)
| | - Sarah Shaver
- Department of Emergency Medicine, University of Texas Southwestern Medical Center, Dallas (A.H.I, B.Y.Y., S.S., M.P.C.)
| | - Mary P Chang
- Department of Emergency Medicine, University of Texas Southwestern Medical Center, Dallas (A.H.I, B.Y.Y., S.S., M.P.C.)
| | - Tom Rea
- Department of Medicine (Emergency Medicine) (T.R.), University of Washington, Seattle
| | - Peter Kudenchuk
- Department of Medicine (Cardiology) (P.K.), University of Washington, Seattle
| | - Jim Christenson
- Department of Biostatistics (B.L., J.C.), University of Washington, Seattle
- Department of Emergency Medicine, University of British Columbia, Vancouver, Canada (J.C.)
| | | | - Clifton Callaway
- Department of Emergency Medicine, University of Pittsburgh, PA (C.C., D.S.)
| | - David Salcido
- Department of Emergency Medicine, University of Pittsburgh, PA (C.C., D.S.)
| | | | - Jennifer Blackwood
- Public Health-Seattle & King County, Emergency Medical Services Division, Seattle, WA (J.B.)
| | - Henry E Wang
- Department of Emergency Medicine, The Ohio State University, Columbus (H.E.W.)
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Estimation of Tidal Volume during Exercise Stress Test from Wearable-Device Measures of Heart Rate and Breathing Rate. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12115441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Tidal volume (TV), defined as the amount of air that moves in or out of the lungs with each respiratory cycle, is important in evaluating the respiratory function. Although TV can be reliably measured in laboratory settings, this information is hardly obtainable under everyday living conditions. Under such conditions, wearable devices could provide valuable support to monitor vital signs, such as heart rate (HR) and breathing rate (BR). The aim of this study was to develop a model to estimate TV from wearable-device measures of HR and BR during exercise. HR and BR were acquired through the Zephyr Bioharness 3.0 wearable device in nine subjects performing incremental cycling tests. For each subject, TV during exercise was obtained with a metabolic cart (Cosmed). A stepwise regression algorithm was used to create the model using as possible predictors HR, BR, age, and body mass index; the model was then validated using a leave-one-subject-out cross-validation procedure. The performance of the model was evaluated using the explained variance (R2), obtaining values ranging from 0.65 to 0.72. The proposed model is a valid method for TV estimation with wearable devices and can be considered not subject-specific and not instrumentation-specific.
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Wik L, Brattebø G, Østerås Ø, Assmus J, Irusta U, Aramendi E, Mydske S, Skaalhegg T, Christjar Skaiaa S, Thomassen Ø. Physiological effects of providing supplemental air for avalanche victims. A randomised trial. Resuscitation 2022; 172:38-46. [DOI: 10.1016/j.resuscitation.2022.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/23/2021] [Accepted: 01/11/2022] [Indexed: 11/28/2022]
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