BACKGROUND In anesthesia practice,orotracheal intubation remains the primary concern of the anesthesiologist.The introduction of video laryngoscopy(VL)has increased the success rate of orotracheal intubation;however,c...BACKGROUND In anesthesia practice,orotracheal intubation remains the primary concern of the anesthesiologist.The introduction of video laryngoscopy(VL)has increased the success rate of orotracheal intubation;however,conflicting results have been reported regarding the usefulness of the current technique with VL in clinical practice.AIM To describe a modification to improve intubation with VL,followed by evaluation of the practice in vivo.METHODS First,a mannequin trial was conducted with operators having different experience and background.Then,a retrospective analysis was performed for an>1-year period with patients who underwent general anesthesia with orotracheal intubation.The endotracheal tube used had been pre-formed with two curves.Stepwise intubation had been performed with direct eye vision,followed by screen assistance and rotation of the tube as needed to direct it toward the glottis.In the mannequin trial,the outcome measures were quantification of torque(force with angular acceleration during levering),need for external maneuvers,and time to intubate.In the clinical experience,orotracheal intubation used VL(pre-formed tube)or direct laryngoscopy(DL)at the anesthetist’s discretion and throat discomfort was reported by the patient.RESULTS In the mannequin trials using VL,there was less torque with the pre-formed tube than with a regular tube(8%and 65%,respectively).The first-pass rate was higher with the pre-formed tube(95%)than with a regular tube(81%).However,the time to intubate was longer with the pre-formed tube than with a regular tube(22 s and 12 s,respectively).In clinical practice,562 patients underwent surgery under general anesthesia with orotracheal intubation using either VL(n=244)or DL(n=318)at the discretion of the attending anesthetist.VL was specifically planned in 62 of the patients,due to anticipated difficulty.Second attempts by readjustment of the curve of the tube were significantly fewer with VL than with DL(10%vs 18%).Throat discomfort was reported by fewer patients who underw展开更多
Torque ripple is one of the most important specification indexes of brushless DC torque motors. This paper analyzes the torque ripple of a sinusoidal-driven three-phase permanent magnet(PM) brushless DC (BLDC) torque ...Torque ripple is one of the most important specification indexes of brushless DC torque motors. This paper analyzes the torque ripple of a sinusoidal-driven three-phase permanent magnet(PM) brushless DC (BLDC) torque motor and approaches the expression of torque ripple. An indirect method using armature currents to measure torque ripple and its implementation by hardware are presented. The torque ripple of the motor is measured by the indirect and the direct methods respecively. The validity of the indirect method is demonstrated by the comparative analysis of the experimental results.展开更多
基金the Ethics and Research Committee of University Hospital Sharjah,No.UHS-HERC-014-30072019.
文摘BACKGROUND In anesthesia practice,orotracheal intubation remains the primary concern of the anesthesiologist.The introduction of video laryngoscopy(VL)has increased the success rate of orotracheal intubation;however,conflicting results have been reported regarding the usefulness of the current technique with VL in clinical practice.AIM To describe a modification to improve intubation with VL,followed by evaluation of the practice in vivo.METHODS First,a mannequin trial was conducted with operators having different experience and background.Then,a retrospective analysis was performed for an>1-year period with patients who underwent general anesthesia with orotracheal intubation.The endotracheal tube used had been pre-formed with two curves.Stepwise intubation had been performed with direct eye vision,followed by screen assistance and rotation of the tube as needed to direct it toward the glottis.In the mannequin trial,the outcome measures were quantification of torque(force with angular acceleration during levering),need for external maneuvers,and time to intubate.In the clinical experience,orotracheal intubation used VL(pre-formed tube)or direct laryngoscopy(DL)at the anesthetist’s discretion and throat discomfort was reported by the patient.RESULTS In the mannequin trials using VL,there was less torque with the pre-formed tube than with a regular tube(8%and 65%,respectively).The first-pass rate was higher with the pre-formed tube(95%)than with a regular tube(81%).However,the time to intubate was longer with the pre-formed tube than with a regular tube(22 s and 12 s,respectively).In clinical practice,562 patients underwent surgery under general anesthesia with orotracheal intubation using either VL(n=244)or DL(n=318)at the discretion of the attending anesthetist.VL was specifically planned in 62 of the patients,due to anticipated difficulty.Second attempts by readjustment of the curve of the tube were significantly fewer with VL than with DL(10%vs 18%).Throat discomfort was reported by fewer patients who underw
文摘Torque ripple is one of the most important specification indexes of brushless DC torque motors. This paper analyzes the torque ripple of a sinusoidal-driven three-phase permanent magnet(PM) brushless DC (BLDC) torque motor and approaches the expression of torque ripple. An indirect method using armature currents to measure torque ripple and its implementation by hardware are presented. The torque ripple of the motor is measured by the indirect and the direct methods respecively. The validity of the indirect method is demonstrated by the comparative analysis of the experimental results.
