The theoretical approach along with the rationale of harmonic excitation modality (HEM) applied as optimal dual controlled ventilation (DCV) to anaesthetized or severe brain injured patients, whose respiretory mechani...The theoretical approach along with the rationale of harmonic excitation modality (HEM) applied as optimal dual controlled ventilation (DCV) to anaesthetized or severe brain injured patients, whose respiretory mechanics can be properly assumed steady and linear, are presented and discussed. The design criteria of an improved version of the Advanced Lung Ventilation System (ALVS), including HEM in its functional features, are described in details. In particular, the elimination of any undesiderable artificial distortion affecting the respiratory and ventilation pattern waveforms is achieved by maintaining continuous forever the airflow inside the ventilation circuit, ensuring also the highest level of safety for patient in any condition. In such a way, the full-time compatibility of controlled breathings with spontaneous breathing activity of patient during continuous positive airways pressure (CPAP) or bilevel positive airways pressure (BiPAP) ventilation modalities and during assisted/controlled ventilation(A/CV), includeing also synchronized or triggered ventilation modalities, is an intrinsic innovative feature of the system available for clinical application. As expected and according to the clinical requirements, HEM provides for physiological respiratory and ventilation pattern waveforms together with optimal “breath to breath” feedback control of lung volume driven by an improved diagnostic measurement procedure, whose outputs are also vital for adapting all the preset ventilation parameters to the current value of the respiratory parameters of patient. The results produced by software simulations concerning both adult and neonatal patients in different clinical conditions are completely consistent with those obtained by the theoretical treatment, showing that HEM reaches the best performances from both clinical and engineering points of view.展开更多
Background：Dual sensor （DS） for rate adaption was supposed to be more physiological.To evaluate its superiority,the DS （accelerometer [ACC] and minute ventilation [MV]） and normal sinus rate response were compare...Background：Dual sensor （DS） for rate adaption was supposed to be more physiological.To evaluate its superiority,the DS （accelerometer [ACC] and minute ventilation [MV]） and normal sinus rate response were compared in a self-controlled way during exercise treadmill testing.Methods：This self-controlled study was performed in atrioventricular block patients with normal sinus function who met the indications of pacemaker implant.Twenty-one patients came to the 1-month follow-up visit.Patients performed a treadmill test 1-month post implant while programmed in DDDR and sensor passive mode.For these patients,sensor response factors were left at default settings （ACC =8,MV =3） and sensor indicated rates （SIRs） for DS,ACC and MV sensor were retrieved from the pacemaker memories,along with measured sinus node （SN） rates from the beginning to 1-minute after the end of the treadmill test,and compared among study groups.Repeated measures analysis of variance and profile analysis,as well as variance analysis of randomized block designs,were used for statistical analysis.Results：Fifteen patients （15/2 l） were determined to be chronotropically competent.The mean differences between DS SIRs and intrinsic sinus rates during treadmill testing were smaller than those for ACC and MV sensor （mean difference between SIR and SN rate：ACC vs.SN,MV vs.SN,DS vs.SN,respectively,34.84,17.60,16.15 beats/min）,though no sensors could mimic sinus rates under the default settings for sensor response factor （ACC vs.SN P-adjusted 〈 0.001; MV vs.SN P-adjusted =0.002; DS vs.SN P-adjusted =0.005）.However,both in the range of 1st minute and first 3 minutes of exercise,only the DS SIR profile did not differ from sinus rates （P-adjusted =0.09,0.90,respectively）.Conclusions：The DS under default settings provides more physiological rate response during physical activity than the corresponding single sensors （ACC or MV sensor）.Further study is needed to determine if individual optimization would further improve adaptive performance of the DS.展开更多
文摘The theoretical approach along with the rationale of harmonic excitation modality (HEM) applied as optimal dual controlled ventilation (DCV) to anaesthetized or severe brain injured patients, whose respiretory mechanics can be properly assumed steady and linear, are presented and discussed. The design criteria of an improved version of the Advanced Lung Ventilation System (ALVS), including HEM in its functional features, are described in details. In particular, the elimination of any undesiderable artificial distortion affecting the respiratory and ventilation pattern waveforms is achieved by maintaining continuous forever the airflow inside the ventilation circuit, ensuring also the highest level of safety for patient in any condition. In such a way, the full-time compatibility of controlled breathings with spontaneous breathing activity of patient during continuous positive airways pressure (CPAP) or bilevel positive airways pressure (BiPAP) ventilation modalities and during assisted/controlled ventilation(A/CV), includeing also synchronized or triggered ventilation modalities, is an intrinsic innovative feature of the system available for clinical application. As expected and according to the clinical requirements, HEM provides for physiological respiratory and ventilation pattern waveforms together with optimal “breath to breath” feedback control of lung volume driven by an improved diagnostic measurement procedure, whose outputs are also vital for adapting all the preset ventilation parameters to the current value of the respiratory parameters of patient. The results produced by software simulations concerning both adult and neonatal patients in different clinical conditions are completely consistent with those obtained by the theoretical treatment, showing that HEM reaches the best performances from both clinical and engineering points of view.
文摘Background：Dual sensor （DS） for rate adaption was supposed to be more physiological.To evaluate its superiority,the DS （accelerometer [ACC] and minute ventilation [MV]） and normal sinus rate response were compared in a self-controlled way during exercise treadmill testing.Methods：This self-controlled study was performed in atrioventricular block patients with normal sinus function who met the indications of pacemaker implant.Twenty-one patients came to the 1-month follow-up visit.Patients performed a treadmill test 1-month post implant while programmed in DDDR and sensor passive mode.For these patients,sensor response factors were left at default settings （ACC =8,MV =3） and sensor indicated rates （SIRs） for DS,ACC and MV sensor were retrieved from the pacemaker memories,along with measured sinus node （SN） rates from the beginning to 1-minute after the end of the treadmill test,and compared among study groups.Repeated measures analysis of variance and profile analysis,as well as variance analysis of randomized block designs,were used for statistical analysis.Results：Fifteen patients （15/2 l） were determined to be chronotropically competent.The mean differences between DS SIRs and intrinsic sinus rates during treadmill testing were smaller than those for ACC and MV sensor （mean difference between SIR and SN rate：ACC vs.SN,MV vs.SN,DS vs.SN,respectively,34.84,17.60,16.15 beats/min）,though no sensors could mimic sinus rates under the default settings for sensor response factor （ACC vs.SN P-adjusted 〈 0.001; MV vs.SN P-adjusted =0.002; DS vs.SN P-adjusted =0.005）.However,both in the range of 1st minute and first 3 minutes of exercise,only the DS SIR profile did not differ from sinus rates （P-adjusted =0.09,0.90,respectively）.Conclusions：The DS under default settings provides more physiological rate response during physical activity than the corresponding single sensors （ACC or MV sensor）.Further study is needed to determine if individual optimization would further improve adaptive performance of the DS.
