1.Controllability and predictability of riboflavin-ultraviolet A collagen cross-linking: advances in experimental techniques and theoretical research.
Xiaona LIU ; Xiaona LI ; Weiyi CHEN
Journal of Biomedical Engineering 2025;42(1):212-218
Riboflavin-ultraviolet A (UVA) collagen cross-linking has not only achieved good clinical efficacy in the treatment of corneal diseases such as dilatation keratopathy, bullae keratopathy, infectious keratopathy, and in the combined treatment of corneal refractive surgeries, but also its efficacy and safety in scleral collagen cross-linking have been initially confirmed. To better promote the application of cross-linking in the clinical treatment of corneal and scleral diseases, exploring controllability and predictability of the surgical efficacy are both important for evaluating the surgical efficacy and personalized precision treatment. In this paper, the progress on the cross-linking depth of riboflavin-UVA collagen cross-linking, and its relationship with the cross-linking effect will be reviewed. It will provide the reference for further application of this procedure in ophthalmology clinics.
Riboflavin/pharmacology*
;
Humans
;
Collagen/radiation effects*
;
Ultraviolet Rays
;
Cross-Linking Reagents
;
Corneal Diseases/drug therapy*
;
Photosensitizing Agents/therapeutic use*
2.Research on a portable electrical impedance tomography system for evaluating blood compatibility of biomaterials.
Piao PENG ; Huaihao CHEN ; Bo CHE ; Xuan LI ; Chunjian FAN ; Lei LIU ; Teng LUO ; Linhong DENG
Journal of Biomedical Engineering 2025;42(2):219-227
The evaluation of blood compatibility of biomaterials is crucial for ensuring the clinical safety of implantable medical devices. To address the limitations of traditional testing methods in real-time monitoring and electrical property analysis, this study developed a portable electrical impedance tomography (EIT) system. The system uses a 16-electrode design, operates within a frequency range of 1 to 500 kHz, achieves a signal to noise ratio (SNR) of 69.54 dB at 50 kHz, and has a data collection speed of 20 frames per second. Experimental results show that the EIT system developed in this study is highly consistent with a microplate reader ( R 2=0.97) in detecting the hemolytic behavior of industrial-grade titanium (TA3) and titanium alloy-titanium 6 aluminum 4 vanadium (TC4) in anticoagulated bovine blood. Additionally, with the support of a multimodal image fusion Gauss-Newton one-step iterative algorithm, the system can accurately locate and monitor in real-time the dynamic changes in blood permeation and coagulation caused by TC4 in vivo. In conclusion, the EIT system developed in this study provides a new and effective method for evaluating the blood compatibility of biomaterials.
Electric Impedance
;
Animals
;
Tomography/instrumentation*
;
Biocompatible Materials
;
Materials Testing/instrumentation*
;
Cattle
;
Titanium
;
Alloys
;
Prostheses and Implants
3.Study on the separation method of lung ventilation and lung perfusion signals in electrical impedance tomography based on rime algorithm optimized variational mode decomposition.
Guobin GAO ; Kun LI ; Junyao LI ; Mingxu ZHU ; Yu WANG ; Xiaoheng YAN ; Xuetao SHI
Journal of Biomedical Engineering 2025;42(2):228-236
Real-time acquisition of pulmonary ventilation and perfusion information through thoracic electrical impedance tomography (EIT) holds significant clinical value. This study proposes a novel method based on the rime (RIME) algorithm-optimized variational mode decomposition (VMD) to separate lung ventilation and perfusion signals directly from raw voltage data prior to EIT image reconstruction, enabling independent imaging of both parameters. To validate this approach, EIT data were collected from 16 healthy volunteers under normal breathing and inspiratory breath-holding conditions. The RIME algorithm was employed to optimize VMD parameters by minimizing envelope entropy as the fitness function. The optimized VMD was then applied to separate raw data across all measurement channels in EIT, with spectral analysis identifying relevant components to reconstruct ventilation and perfusion signals. Results demonstrated that the structural similarity index (SSIM) between perfusion images derived from normal breathing and breath-holding states averaged approximately 84% across all 16 subjects, significantly outperforming traditional frequency-domain filtering methods in perfusion imaging accuracy. This method offers a promising technical advancement for real-time monitoring of pulmonary ventilation and perfusion, holding significant value for advancing the clinical application of EIT in the diagnosis and treatment of respiratory diseases.
Humans
;
Electric Impedance
;
Algorithms
;
Tomography/methods*
;
Pulmonary Ventilation/physiology*
;
Lung/diagnostic imaging*
;
Image Processing, Computer-Assisted/methods*
;
Adult
4.Application of electrical impedance tomography in diagnosis and monitoring of pulmonary diseases.
Xiaomin HU ; Shuaifu ZHANG ; Panfeng CHEN ; Feng DONG ; Haojun FAN ; Qi LYU ; Yanbin XU
Journal of Biomedical Engineering 2025;42(2):389-395
Electrical impedance tomography (EIT) is a new non-invasive functional imaging technology, which has the advantages of non-invasion, non-radiation, low cost, fast response, portability and visualization. In recent years, more and more studies have shown that EIT has great potential in the detection of lung diseases and has been applied to early diagnosis and treatment of some diseases. This paper introduced the basic principle of EIT, discussed the research and clinical application of EIT in the detection of acute respiratory distress syndrome, chronic obstructive pulmonary disease, pneumothorax and pulmonary embolism, and focused on the summary and introduction of indicators and functional images of EIT related to the detection of lung diseases. This review will help medical workers understand and use EIT, and promote the further development of EIT in lung diseases as well as other fields.
Humans
;
Electric Impedance
;
Tomography/methods*
;
Lung Diseases/diagnosis*
;
Pulmonary Disease, Chronic Obstructive/diagnosis*
;
Pulmonary Embolism/diagnosis*
;
Respiratory Distress Syndrome/diagnosis*
5.Development of a balloon sensor device for force-electrical coupling measurement of esophagus.
Peng RAN ; Ying ZHONG ; Yingbing LAI ; Lei LIU ; Yanhang ZHU ; Huantao ZHU
Journal of Biomedical Engineering 2025;42(3):610-619
To address the challenges of capturing micro-strains in detecting esophageal motility disorders and the limitations of existing high-resolution manometry and functional intraluminal imaging probes in directly measuring esophageal tissue electrical impedance, this study proposes a novel flexible balloon sensor structure that integrates a piezoelectric film assembly with a distributed impedance electrode array. Using the electrical analysis module in the finite element analysis (FEA) software, simulations of the forward problem for esophageal impedance detection were conducted to optimize the excitation source parameters, and a physical prototype was fabricated. Under a relative excitation mode with a voltage sensitivity of 2.059%, the voltage output characteristics of the impedance electrode array were analyzed during linear changes in the balloon filling volume. Based on the performance variation of the piezoelectric film assembly, 80% was selected as the optimal filling volume. Force-electric coupling tests were conducted on the balloon sensor using a pressure testing platform, revealing that both the piezoelectric film assembly inside the balloon and the impedance electrodes outside the balloon exhibited significant load differentiation characteristics as the force application point shifted. In summary, this balloon sensor facilitates the localization of force application while simultaneously analyzing esophageal tissue properties, offering a novel diagnostic approach and objective tool for esophageal disease detection.
Esophagus/physiology*
;
Electric Impedance
;
Humans
;
Finite Element Analysis
;
Manometry/methods*
;
Electrodes
;
Esophageal Motility Disorders/physiopathology*
;
Equipment Design
6.Preparation and application of conductive fiber coated with liquid metal.
Chengfeng LIU ; Jiabo TANG ; Ming LI ; Shihao ZHANG ; Yang ZOU ; Yonggang LYU
Journal of Biomedical Engineering 2025;42(4):724-732
Flexible conductive fibers have been widely applied in wearable flexible sensing. However, exposed wearable flexible sensors based on liquid metal (LM) are prone to abrasion and significant conductivity degradation. This study presented a high-sensitivity LM conductive fiber with integration of strain sensing, electrical heating, and thermochromic capabilities, which was fabricated by coating eutectic gallium-indium (EGaIn) onto spandex fibers modified with waterborne polyurethane (WPU), followed by thermal curing to form a protective polyurethane sheath. This fiber, designated as Spandex/WPU/EGaIn/Polyurethane (SWEP), exhibits a four-layer coaxial structure: spandex core, WPU modification layer, LM conductive layer, and polyurethane protective sheath. The SWEP fiber had a diameter of (458.3 ± 10.4) μm, linear density of (2.37 ± 0.15) g/m, and uniform EGaIn coating. The fiber had excellent conductivity with an average value of (3 716.9 ± 594.2) S/m. The strain sensing performance was particularly noteworthy. A 5 cm × 5 cm woven fabric was fabricated using polyester warp yarns and SWEP weft yarns. The fabric exhibited satisfactory moisture permeability [(536.06 ± 33.15) g/(m 2·h)] and maintained stable thermochromic performance after repeated heating cycles. This advanced conductive fiber development is expected to significantly promote LM applications in wearable electronics and smart textile systems.
Wearable Electronic Devices
;
Polyurethanes/chemistry*
;
Electric Conductivity
;
Gallium/chemistry*
;
Metals/chemistry*
7.Study on the electric field transmission characteristics of conducted-electrode tumor treating fields.
Kaida LIU ; Junxia ZHANG ; Jiaqi SHI ; Haohan FANG ; Xing LI
Journal of Biomedical Engineering 2025;42(5):964-969
Tumor treating fields (TTF) therapy is an innovative tumor treatment modality. Currently, the TTF devices predominantly employ insulated ceramic electrodes as the electric field transmission medium, resulting in low energy transfer efficiency of the electric field and poor portability of the devices. This study proposed an innovative TTF transmission mode and independently designed a conducted-electrode TTF cell culture dish utilizing inert titanium materials. The electric field conduction characteristics were verified through finite element simulations and experimental tests. Finally, based on the self-manufactured conducted-electrode TTF cell culture dish, experiments on the proliferation inhibition of U87 tumor cells by TTF were conducted. The results demonstrated that under an applied TTF voltage of 10 V and frequency of 200 kHz, the electric field intensities within the medium for conducted and insulated electrodes are approximately 2.5 V/cm and 0.7 V/cm, respectively. Compared to conventional insulated TTF systems, the conducted-electrode TTF configuration exhibited a lower electrode voltage drop and a higher electric field intensity in the culture medium, indicating superior electric field transmission efficiency. Following 36 hours of treatment with conducted-electrode TTF on U87 cells, the proliferation inhibition rate reached approximately 50%, demonstrating effective suppression of tumor cell growth. This approach presents a potential direction for optimizing TTF treatment modality and device design.
Humans
;
Electrodes
;
Neoplasms/pathology*
;
Cell Line, Tumor
;
Cell Proliferation/radiation effects*
;
Electric Stimulation Therapy/methods*
;
Electromagnetic Fields
8.Experimental study on the treatment of postmenopausal osteoporosis with low-frequency pulsed electromagnetic fields.
Zidong AN ; Liqiang WANG ; Yi WU ; Yongjie PANG ; Keming CHEN ; Yuhai GAO
Journal of Biomedical Engineering 2025;42(5):1054-1061
This study aims to investigate the therapeutic efficacy of 50 Hz-0.6 mT low-frequency pulsed electromagnetic field (PEMF) on postmenopausal osteoporosis in ovariectomized rats. Thirty 3-month-old female SD rats were selected and divided into a sham operation group (Sham), an ovariectomized model group (OVX), and a low-frequency pulsed electromagnetic field (PEMF) treatment group, with 10 rats in each group. After 8 weeks, the whole-body bone mineral density (BMD) of each group of rats was measured. The treatment group began to receive PEMF stimulation for 90 minutes daily, while the OVX group only received a simulated placement without electricity. After 6 weeks of intervention, all rats were sacrificed and tested for in vitro BMD, micro-CT, biomechanics, serum biochemical indicators, and bone tissue-related proteins. The results showed that the BMD of the OVX group was significantly lower than that of the Sham group 8 weeks after surgery, indicating successful modeling. After 6 weeks of treatment, compared with the OVX group, the PEMF group exhibited significantly increased BMD in the whole body, femur, and vertebral bodies. Micro-CT analysis results showed improved bone microstructure, significantly increased maximum load and bending strength of the femur, elevated levels of serum bone formation markers, and increased expression of osteogenic-related proteins. In conclusion, this study demonstrates that daily 90-minute exposure to 50 Hz-0.6 mT PEMF effectively enhances BMD, improves bone biomechanical properties, optimizes bone microstructure, stimulates bone formation, and inhibits bone resorption in ovariectomized rats, highlighting its therapeutic potential for postmenopausal osteoporosis.
Female
;
Animals
;
Rats, Sprague-Dawley
;
Osteoporosis, Postmenopausal/therapy*
;
Rats
;
Bone Density
;
Ovariectomy
;
Magnetic Field Therapy/methods*
;
Electromagnetic Fields
9.Infrared thermography-assisted design and harvesting of ultrathin anterolateral thigh perforator flaps.
Chenxi ZHANG ; Jiadong PAN ; Shanqing YIN ; Guoqing SHAO ; Xianting ZHOU ; Gaoxiang YU ; Luzhe WU ; Xin WANG
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(9):1143-1148
OBJECTIVE:
To explore the application value of infrared thermography in the design and harvesting of ultrathin anterolateral thigh perforator flaps.
METHODS:
Between June 2024 and December 2024, 9 cases of ultrathin anterolateral thigh perforator flaps were designed and harvested with the assistance of infrared thermography. There were 7 males and 2 females, aged 21-61 years (mean, 39.8 years). The body mass index ranged from 19.49 to 26.45 kg/m² (mean, 23.85 kg/m²). Causes of injury included 5 cases of traffic accident injuries and 4 cases of machine crush injuries. There were 3 cases of leg wounds, 2 cases of foot wounds, and 4 cases of hand wounds. After debridement, the size of wound ranged from 7 cm×4 cm to 13 cm×11 cm. The time from admission to flap repair surgery was 5-12 days (mean, 7 days). Preoperatively, perforator localization was performed using a traditional Doppler flow detector and infrared thermography, respectively. The results were compared with the actual intraoperative locations; a discrepancy ≤10 mm was considered as consistent localization (positive), and the positive predictive value was calculated. All 9 cases were repaired with ultrathin anterolateral thigh perforator flaps designed and harvested based on thermographic images. The size of flap ranged from 8 cm×5 cm to 14 cm×8 cm, with a thickness of 3-6 mm (mean, 5.2 mm). One donor site was repaired with a full-thickness skin graft, and the others were sutured directly. Postoperatively, anti-inflammatory, anticoagulant, and anti-vascular spasm treatments were administered, and follow-up was conducted.
RESULTS:
The Doppler flow detector identified 22 perforating vessels within the set range, among which 16 were confirmed as superficial fascia layer perforators intraoperatively, with a positive predictive value of 72.7%. The infrared thermograph detected 23 superficial fascia layer perforating vessels, and 21 were verified intraoperatively, with a positive predictive value of 91.3%. There was no significant difference between the two methods [OR (95%CI)=3.93 (0.70, 22.15), P=0.100]. The perforator localization time of the infrared thermograph was (5.1±1.3) minutes, which was significantly shorter than that of the Doppler flow detector [(10.1±2.6) minutes; MD (95%CI)=-5.00 (-7.08, -2.91), P<0.001]. Postoperatively, 1 case of distal flap necrosis healed after dressing change; all other flaps survived successfully. The skin grafts at donor site survived, and all incisions healed by first intention. All patients were followed up 3-6 months (mean, 4.7 months). No pain or other discomfort occurred at the donor or recipient sites. All patients with foot wounds could walk with shoes, and no secondary flap revision was required. Flaps in 3 hand wound cases, 2 foot wound cases, and 3 leg wound cases recovered light touch and pressure sensation, but not pain or temperature sensation; the remaining 2 cases had no sensory recovery.
CONCLUSION
Preoperative localization using infrared thermography for repairing ultrathin anterolateral thigh perforator flaps can help evaluate the blood supply status of perforators, reduce complications, and improve surgical safety and flap survival rate.
Humans
;
Perforator Flap/blood supply*
;
Adult
;
Male
;
Thermography/methods*
;
Female
;
Thigh/blood supply*
;
Middle Aged
;
Plastic Surgery Procedures/methods*
;
Tissue and Organ Harvesting/methods*
;
Infrared Rays
;
Skin Transplantation/methods*
;
Soft Tissue Injuries/surgery*
;
Young Adult
10.Clinical analysis of nutritional components in children with acute leukemia.
Li-Xia SHI ; Ming-Zhong ZHAO ; Fei-Fei WANG ; Yu-Qian XING ; Hong-Yan JI ; Ping ZHAO
Chinese Journal of Contemporary Pediatrics 2025;27(3):300-307
OBJECTIVES:
To assess the changes in body composition and nutritional risks faced by children with different stages of acute leukemia (AL).
METHODS:
Bioelectrical impedance analysis combined with anthropometric measurements was used to detect body composition. This prospective study was conducted from August 2023 to July 2024 at Shandong Provincial Hospital, examining the body composition and physical balance of children with various stages of AL and healthy children.
RESULTS:
The non-fat components of children with AL and healthy children both showed a linear increase with age. In the younger age group, there were no significant differences in body composition between children with AL and healthy children. However, in the older age group, the body composition of children undergoing chemotherapy for AL was significantly lower than that of healthy children (P<0.05), and muscle mass recovered first after the completion of AL chemotherapy. The proportion of children with increased trunk fat in AL children who completed chemotherapy was significantly lower than that in healthy children (P<0.05), while the incidence rate of severe left-right imbalance in body composition was significantly higher (P<0.05). Muscle distribution in children with AL primarily showed insufficient limb and overall muscle mass, whereas healthy children mainly exhibited insufficient upper limb muscle mass.
CONCLUSIONS
The body composition of children with AL varies at different treatment stages, indicating that nutritional status is affected by both the disease itself and the treatment. Early screening can provide a basis for reasonable nutritional intervention.
Humans
;
Child
;
Male
;
Female
;
Child, Preschool
;
Body Composition
;
Prospective Studies
;
Adolescent
;
Leukemia/metabolism*
;
Infant
;
Nutritional Status
;
Acute Disease
;
Electric Impedance

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