In saliency‐based sensorless methods, the amplitude of the injected voltage cannot be reduced to levels below its specified value because of the reasonable signal required for the noise ratio. Increasing the injection signal amplitude increases not only the acoustic noise and high‐frequency (HF) losses, but also the total harmonic distortion (THD) of the output voltage and current ripples. A new pulsating semi‐impulse signal injection method based on the current sensing technique is proposed for the sensorless control of interior permanent magnet synchronous motors (IPMSMs). The proposed method aims to control the motor speed and reduce some problems due to the HF signal injection involving acoustic noise, HF losses and THD of the output voltage. Taking into account the premium injection angle, these problems are reduced significantly as compared to those in conventional square‐wave methods. Hence, the proposed method increases the sensorless driver efficiency and its application scope. The effectiveness of the proposed method is then confirmed with computer simulation and experimental tests. Experimental comparisons at the same injection frequency and injection effective voltage show that the performance of the proposed method is beneficial. All experiments were performed on a IPMSM with V‐shaped PMs which is used in a refrigerator compressor.

Radiofrequency catheter ablation is an interventional procedure used to treat arrhythmia. An electrode catheter that could inject saline has been developed to prevent steam pop on heart tissue during radiofrequency catheter ablation. Thus, we investigated to numerical model on the effect of saline injection and heart tissue’s deformation. In this study, the hyperelastic model was implemented to analyze heart tissue deformation due to the catheter’s contact force. Besides, the advection–diffusion equation was used to analyze the mixture between saline and blood. We developed the multiphysics model that predicts thermal lesions based on the deformation of the heart and mixing between saline and blood flow. The thermal lesion and the maximum temperature in the numerical model that considered mixing saline and blood were smaller than that of other numerical models that did not consider mixing. Therefore, we observed that the saline injection was affected by thermal lesion due to higher electrical conductivity than blood flow and injection at a lower temperature than the human body. The numerical model was researched that considering the deformation of the heart tissue and saline injection in radiofrequency catheter ablation affects the heart tissue’s thermal lesion and maximum temperature.

Computer modeling and simulation (CM&S) technology is widely used in the medical device industry due to its advantages such as reducing testing time and costs. However, the developer’s parameter settings during the modeling and simulation process can have a significant impact on the results. This study developed a test model for the rotational shear strength of dental implants and the constraint force of total knee replacements based on CM&S technology and proposes ideal parameters to ensure reliability. For dental implants, the load area and sliding contact conditions were considered, and for total knee replacements, the friction coefficient, medial–lateral displacement, valgus–varus rotation, and elastic modulus were considered. By comparing the simulation results and mechanical tests, boundary conditions with an error rate of less than 1.5% were selected. When a jig (gripper and collector) was applied with the same boundary conditions, an error rate of 48~22% occurred; otherwise, it was confirmed that the error rate was within 10~0.2%. The FE model was verified with an error of 2.49 to 3% compared to the mechanical test. The friction coefficient variable had the greatest influence on the results, accounting for 10 to 13%, and it was confirmed that valgus–varus rotation had a greater influence on the results than medial–lateral displacement. Relatively, the elastic modulus of the insert had the least effect on the results. These research results are expected to make CM&S techniques useful as a medical device digital development tool (M3DT) in the development of total knee replacements and dental implants.

This paper presents a design and control of one- wheel type hybrid wheelchair which is operated by the manual power and electric power together. The proposed hybrid wheelchair uses motorized one wheel for the manual wheelchair to supply the assistant power. The proposed one-wheel type hybrid wheelchair uses a BLDC(Brushless DC) motor, and the motorized part can be easily attachable and detachable from the conventional manual wheelchair. In this paper, an indirect estimation for PAS(Power Assistant System) is proposed. The user requirement for the moving of the wheelchair is estimated by the acceleration sensor. A novel estimation factor of the user action is presented, then the reference torque for the assistant power motor is determined by the proposed factor. The detailed design and analysis of the proposed hybrid wheelchair are detailed presented with the simulation and experimental results.

In this paper, comparative analysis of 4/2 and 6/4 poles high-speed Switched Reluctance Motors (SRMs) for electric supercharger (ESC) is executed. Radial force is known to be the biggest cause of stator vibration. Stator geometry of the proposed motors is optimized to reduce radial force which may lead to reduced stator vibration. A speed control by Adaptive Neuro-Fuzzy Inference System (ANFIS), which receives speed error as input and current reference as output, is adopted in high speed region for easier and faster implementation. The characteristics of the motors are examined with finite element analysis (FEA) in Ansoft Maxwell while the response time of the motor is simulated in MATLAB Simulink. Both motor performances are also compared.

BLSRM (Bearingless Switched Reluctance Motor) is a nonlinear, strong coupling and multi-variable system. The convertional control method is vulnerable to uncertain factors such as the load disturbance and satellite parameters' change. It is difficult to obtain a satisfactory control effect. Basing on a novel 8/10 BLSRM, whose suspending force control is separated with the torque control, this paper presents a novel suspending force control scheme. Conventional PID controllers in BLSRM radial force control must set initial parameters in advance according to engineers' knowledge, which will be unchanged during regulation. In order to solve this problem, adaptive fuzzy logic is applied to convertional PID controller for parameters self-tuning in this paper. Both fuzzy and parameters of PID controller are self-tuning on-line, which improve the performance of controller. Finally, simulation and experimental results show the performance of the proposed method.