The Specifics of Calculating the Efficiency of the Continuously Variable Mechanical Transmission with Oscillatory Movement of Internal Links and Force Function Control

The paper discusses the energy flow in the continuously variable mechanical transmission with oscillatory movement of internal links and force function control. It is proposed to treat the potential energy of the twisted torsion bars, which is transferred back to the drive shaft, as useful. The formula for calculating the transmission efficiency, taking into account the return of energy flow back to the motor, hysteresis losses, and energy dissipation in the mechanical rectifier while taking up the free play, is given. When calculating the efficiency of the continuously variable mechanical transmission, it is suggested to take into consideration the clearances in the rectifier and kinematic pairs using ‘kinematic efficiency’. The examples of measured and calculated transmission efficiency in the ‘stop’ mode are given.

Improving Hydroxychloroquine Dosing and Toxicity Screening at a Tertiary Care Ambulatory Center: A Quality Improvement Initiative

Objective.Hydroxychloroquine (HCQ) is a commonly used weight-based medication with a risk of retinal toxicity when prescribed at doses above 5 mg/kg/day. The objectives of our study were (1) to characterize the frequency of inappropriate HCQ dosing and retinopathy screening, and (2) to improve guideline-based management by implementing quality improvement (QI) strategies.Methods.A retrospective chart review was performed to obtain baseline analysis of HCQ dosing, weight documentation, and retinal toxicity screening to characterize current practices. The primary aim was to increase the percentage of patients appropriately dosed from 30% to 90% over a 10-month period. The secondary aim was to increase the percentage of documented retinal screening from 59% to 90%. The process measure was the number of patients with a documented weight in the chart. The balancing measure was the physician’s perceived increase in time spent with each patient due to implemented interventions. QI methodology was used to implement sequential change ideas: (1) HCQ weight-based dosing charts to facilitate prescription regimens; (2) addition of scales to patient rooms to facilitate weight documentation; and (3) electronic medical record (EMR) “force function” involving weight documentation and autodosing prescription.Results.The percentage of patients being weighed increased from 40% to 92% after 10 months. Appropriate HCQ dosing improved from 30% to 89%. Retinal screening documentation improved by 33%.Conclusion.Dosing charts in clinic rooms, addition of weight scales, and EMR force function autodosing prescriptions significantly improved appropriate HCQ dosing practices. These interventions are generalizable and can promote safe and guideline-based care.