In this paper is proposed a new PCB coreless planar circular spiral inductor coils-based transcutaneous energy transfer method for use in implantable biomedical devices. Firstly, the main factor, coupling coefficient k between transmitting and receiving coils, which affected the efficiency of the energy transfer, was determined by setting up the circuit model of transcutaneous energy transfer. Then, the coupling coefficient was analyzed and calculated by using the method of equivalent circular filaments. Finally, experiments were carried out to demonstrate the feasibility of the proposed method.
Electric Power Supplies ; adverse effects ; statistics & numerical data ; Electromagnetic Fields ; Electronics, Medical ; Energy Transfer ; Equipment Design ; Equipment Failure Analysis ; Humans ; Prostheses and Implants

BACKGROUND:Many studies have shown that total hip arthroplasty will improve low back pain in patients with hip-spine syndrome.However,there are few studies on the relationship between postoperative low back pain improvement and changes in spinal-pelvic sagittal parameters.This study aims to reveal their connections between the two. OBJECTIVE:To explore the relationship between the improvement of low back pain and changes in the spinal-pelvic sagittal parameters in patients with hip-spine syndrome after total hip arthroplasty. METHODS:A retrospective analysis was performed on the clinical and imaging data of 93 end-stage hip disease patients who underwent primary total hip arthroplasty and combined with low back pain and were admitted to Affiliated Hospital of Xuzhou Medical University from January 2019 to January 2022.Spinal-pelvic sagittal parameters were measured on lateral lumbar X-rays before surgery and 1 year at the last follow-up:pelvic incidence,pelvic tilt,sacral slope,lumbar lordosis,pelvic incidence-lumbar lordosis(difference between pelvic incident angle and lumbar lordosis angle).Visual analog scale score,Oswestry disability index,and hip Harris score were recorded before and 1 year after arthroplasty.The patients were divided into two groups according to whether the change in visual analog scale scores 1 year after surgery reached the minimal clinically important difference for low back pain treatment,including 45 cases in the low back pain unimproved group and 48 cases in the low back pain improved group.The preoperative general data of patients,differences in spinal-pelvic sagittal parameters,Oswestry Disability Index and hip Harris score before and after surgery were compared between the two groups. RESULTS AND CONCLUSION:(1)There was no significant difference in age,gender,surgical side,body mass index,and etiology between the two groups(P>0.05),and they were comparable.(2)There was no significant difference in visual analog scale scores before surgery(P>0.05).The visual analog scale scores of the low back pain improved group were lower than those of the low back pain unimproved group 1 year after surgery(P<0.01).(3)At 1 year after surgery,the lumbar lordosis of the low back pain unimproved group was significantly smaller than that before surgery,while the lumbar lordosis of the low back pain improved group was significantly smaller than that before surgery(P<0.01).At the same time,the pelvic incidence-lumbar lordosis mismatch in the low back pain unimproved group was greater than before surgery,while the pelvic incidence-lumbar lordosis mismatch in the low back pain improved group was smaller than before surgery,with significant differences between the two groups(P<0.01).There was no significant difference in the changes of other spinal-pelvic sagittal parameters between the two groups(P>0.05).(4)Preoperative lumbar Oswestry disability index and hip Harris score were not significantly different between the two groups(P>0.05).At 1 year after surgery,Oswestry disability index of the low back pain improved group was lower than that of the low back pain unimproved group and the hip Harris score was higher than that of the low back pain unimproved group(P<0.05).(5)The results showed that the improvement of low back pain was related to changes in spinal-pelvic sagittal parameters in patients with hip-spine syndrome after total hip arthroplasty,showing reduced lumbar lordosis and pelvic incidence-lumbar lordosis mismatch.Moreover,patients with improved low back pain after surgery had better functional scores,indicating that total hip arthroplasty improved spinal alignment and spinal-pelvic sagittal balance.For patients with hip-spine syndrome,a total hip arthroplasty performed before the onset of lumbar disease can have a favorable effect on the lumbar spine.

OBJECTIVE To investigate the improvement effect and potential mechanism of “Layers adjusting external application” paste on synovial fibrosis （SF） in rats with knee osteoarthritis （KOA）. METHODS Male SD rats were randomly divided into sham operation group， KOA group and Layers adjusting external application group， with 8 rats in each group. KOA model was induced by the anterior cruciate ligament disruption method in KOA group and Layers adjusting external application group. Fourteen days after modeling， the Layers adjusting external application group was given “Layers adjusting external application” paste [Sanse powder （8 g for every 100 cm2）， Compound sanhuang ointment （5 g for every 100 cm2）] on the knee joint， 8 h every day， for 28 d in total. After the last administration， the degree of synovitis and fibrosis in rats was observed， and Krenn scoring was performed in each group. The expressions of collagen Ⅰ， high mobility group protein B1 （HMGB1） and phosphorylated nuclear factor-κB p65 （p-NF-κB p65） were detected in the synovial membrane； the contents of interleukin-1β （IL- 1β）， IL-6 and tumor necrosis factor-α （TNF-α） in serum as well as the expressions of fibrosis-related and HMGB1/Toll-like receptor 4 （TLR4）/NF-κB signaling pathway-related proteins and mRNA were detected in synovial tissue. RESULTS Compared with the sham operation group， the synovial lining cells in the KOA group showed significant proliferation and disordered arrangement， the inflammatory cell infiltration and collagen fiber deposition were obvious； the positive expressing cells of collagen Ⅰ， HMGB1 and p-NF-κB p65 were increased significantly； the contents of IL-1β， IL-6 and TNF-α in serum， the expressions of fibrosis-related protein （transforming growth factor-β， collagen Ⅰ， tissue inhibitor of metalloproteinase 1， α-smooth muscle actin） and their mRNA as well as theexpressions of HMGB1， TLR4 protein and their mRNA， the expressions of p-NF-κB p65 protein and NF-κB p65 mRNA were all increased significantly in synovial tissues of rats （P＜0.01）. Compared with the KOA group， the pathological changes in the synovial tissue of rats in Layers adjusting external application group were significantly improved， and the above quantitative indicators were significantly reversed （P＜0.05 or P＜0.01）. CONCLUSIONS “Layers adjusting external application” paste could significantly improve SF in KOA rats， the mechanism of which may be associated with the inhibition of the activation of HMGB1/ TLR4/NF-κB signaling pathway.