To investigate the effects of patient bone mass differences on the stability of unicondylar knee arthroplasty (UKA) prostheses.

A UKA finite element model was established to quantify the effects of five different bone quality conditions on the proximal tibial von Mises stress, bone-prosthesis fixation interface contact stress, and bone-prosthesis fixation interface micromotion, using the medial knee force and joint motion predicted by the individualized UKA musculoskeletal multibody dynamics model as boundary conditions.

The influences of bone strength on the proximal tibia von Mises stress and bone-prosthesis fixation interface contact stress were not obvious, and the difference in peak values of the proximal tibia von Mises stress between two groups of models with the largest difference in bone strength was not more than 5%, and the difference in peak values of the bone-prosthesis fixation interface contact stress was only 2.37 MPa. However, the influence of bone strength on the bone-prosthesis fixation interface micromotion was significant, and the weaker bones were more prone to cause the bone-prosthesis fixation interface micromotion. However, bone strength had a significant effect on the bone-prosthesis fixation interface micromotion, and weak bone was more likely to cause changes in the bone-prosthesis fixation interface micromotion. Compared to patients with the neutral bone quality, the prosthesis fixation interface micromotion increased by 84.67% at 20% gait cycles for patients with the weakest bone quality.

UKA patients with a weaker bone quality have a higher risk of prosthesis loosening. It is recommended that surgeons should carefully choose their surgical strategy in order to reduce the rate of postoperative revision in UKA.

By applying the long short-term memory (LSTM) neural network model and using lower body landmark coordinates obtained from a markerless motion capture system as inputs, to estimate ground reaction force (GRF) curves during running.

The video images and GRF data of 59 amateur runners during running were collected by the markerless motion capture system and three-dimensional (3D) force plates. The LSTM model was established, and the 3D coordinates of 11 lower body landmarks, obtained via the Theia3D markerless system, were used as inputs to estimate the 3D GRF curves during the stance of running. The estimation performance was evaluated using correlation coefficients r, root mean square error (RMSE), and normalized root mean square error (nRMSE) by comparing LSTM model estimation and force plate measurement. Statistical parametric mapping was used to analyze differences in GRF curves estimated by the LSTM model and measured by the force plate, while paired t-tests were used to assess differences in GRF characteristics between model estimation and actual measurement.

A strong correlation (r>0.85, P<0.001) and lower error (RMSE<0.3 body weight, nRMSE<15%) was found between the LSTM model estimation and actual measurements. No significant difference was found in GRF curve intervals between LSTM model estimation and actual measurements. There was no significant difference in GRF characteristics between LSTM model estimation and actual measurements (P>0.05).

Based on the LSTM model, the 3D GRF curves can be effectively estimated by lower body landmark coordinates obtained from the makerless motion capture system, thereby acquiring the highly accurate GRF characteristics. The LSTM model developed in this study can be used to monitor injury risks during running in outdoor environments.

To analyze the effects and differences of two veno-arterial extracorporeal membrane oxygenation (VA-ECMO) cannulation methods and subsequent left ventricular unloading on cardiac function and hemodynamics.

The lumped parameter model (LPM) of VA-ECMO integrated with the cardiovascular system in the MATLAB/Simulink environment was extended to simulate and analyze the changes in ventricular function and blood flow in the heart failure patient model under central VA-ECMO or peripheral VA-ECMO support. The effects of using arterial vasodilators or a left atrial drainage cannula on left ventricular function under central VA-ECMO support at a pump flow rate of 3 L/min were compared.

Under central VA-ECMO or peripheral VA-ECMO support, left ventricular pressure and volume increased, and stroke volume and ventricular work decreased. Both arterial vasodilators and the left atrial drainage cannula could reduce left ventricular pressure and volume. Arterial vasodilators additionally increased stroke volume and improved left ventricular ejection fraction from 11.6% to 19.5%.

Both VA-ECMO cannulation methods provide effective circulatory support in the heart failure patient model, with similar effects on ventricular function. Under central VA-ECMO support, arterial vasodilators can improve left ventricular function more effectively than the left atrial drainage cannula.

To investigate the effect of postoperative reduction quality in femoral neck fracture internal fixation on mechanical properties of the femoral head from the perspective of trabecular bone biomechanics.

From patients who underwent hip replacement surgery for femoral neck fractures, a total of 26 femoral head slice specimens were obtained. The central axis of the primary compressive trabeculae was defined as the 0° group, with the intersection point of the primary compressive trabeculae and the femoral calcar serving as the center. By rotating the specimens to simulate different reduction angles, the cut femoral head slice specimens were randomly divided into five groups: -10°, -5°, 0°, 5°, and 10°, representing femoral heads with varying reduction qualities. The specimens were subjected to single compression load tests and fatigue load tests. The load was set from 70 N to 1 400 N, at a frequency of 1 Hz, with 10 000 cycles. Axial stiffness, displacement, and the number of collapse cycles were measured, to compare the biomechanical properties of femoral head specimens under different reduction qualities.

There were differences in the axial stiffness, displacement, and number of collapse cycles among the femoral head specimens in different groups. Under 800 N load, the axial stiffness of 0° group was significantly greater than that of ±10° groups (P<0.05). The axial stiffness of 0° group was also greater than that of the ±5° groups, but the differences were not statistically significant (P>0.05). The axial stiffness of ±5° groups was greater than that of ±10° groups (P<0.05). 0° group had a lower displacement than ±5° groups and ±10° groups. However, the differences in displacement between 0° group and ±5° groups were not statistically significant (P>0.05), while the differences between the 0° group and ±10° groups were statistically significant (P<0.05). The differences in displacement between ±5° groups and ±10° groups were also statistically significant (P<0.05). 0° group had a significantly higher number of collapse cycles than ±10° groups (P<0.05). The number of collapse cycles in 0° group was also higher than that in ±5° groups, but the differences were not statistically significant (P>0.05). The number of collapse cycles in ±5° groups was significantly higher than that ±10° groups (P<0.05).

The quality of reduction after internal fixation of femoral neck fractures significantly affects the biomechanical properties of the femoral head. This study provides a scientific basis for optimizing treatment and postoperative management, aiming to improve clinical outcomes and patients’ quality of life.

To analyze the reverse mechano-electric effect of the layered structure of articular cartilage and its influencing factors.

The cartilage samples were classified according to their physiological thickness (approximately 0.4 mm for the upper layer, 1 mm for the middle layer, and 0.6 mm for the lower layer). Through a non-contact external electric field testing method, how different influencing factors affected the reverse mechano-electric effect of articular cartilage was analyzed.

When the electric field spacing decreased, water content increased, and in vitro time decreased, the displacement of normal layered cartilage in a non-contact electric field increased by 18, 10, 15 μm, respectively. In the case of simulated arthritis defects, as the defect depth and radius increased, the overall deviation deflection of articular cartilage gradually decreased by about 7 μm.

The three-layer cartilage differed in their reverse mechano-electricity effects, showing the greatest deflection in the middle layer at 90% water content, under 7 mm electric field spacing, and after 12 hours ex vivo.

To achieve non-invasive and precise prediction of mean arterial pressure (MAP) based on a fully convolutional neural network (FCNN).

A high-precision blood pressure data acquisition system compliant with international metrological standards was used in conjunction with the ‘gold standard’ auscultation method to collect blood pressure and pulse waveform data from patients. True MAP values were derived via Gaussian fitting of pulse waveform data, constructing a traceable dataset. The FCNN was applied to this dataset to develop a novel MAP prediction method. Additionally, the predictive accuracy of the FCNN was compared with linear regression and conventional empirical formulas.

The mean squared errors (MSE) for MAP prediction using the FCNN, linear regression, and empirical formulas were 19.76, 21.40, and 30.97, respectively. The coefficients of determination (R²) were 0.90, 0.89, and 0.84, and the prediction accuracies were 0.90, 0.89, and 0.85, respectively.

By using systolic blood pressure, diastolic blood pressure, age, and arm circumference as input parameters, the FCNN-based MAP prediction method significantly reduces the bias of empirical formulas. This approach not only improves the accuracy of hemodynamic boundary condition acquisition but also contributes to refining the metrological traceability system of non-invasive blood pressure measurement.

The analgesic effect of manual acupuncture on acute adjuvant arthritis (AA) rats was evaluated using flurbiprofen cataplasm as a positive control, and the role of mast cells in the mechanism of analgesia was explored.

24 SD rats were randomly divided into model group, 10-minute manual acupuncture group, and 30-minute flurbiprofen cataplasm treatment group. AA rat models were established, and treatments were applied at the Zusanli acupoint, while the model group received no treatment. The rats' pain thresholds under mechanical and thermal stimuli were measured before and after the therapy. Acupoint tissue sections were collected and stained, and the mast cell degranulation rate at the acupoint tissue was calculated for each experimental group.

Mechanical and thermal pain thresholds were significantly increased in 10-minute manual acupuncture group compared to those before therapy (P<0.000 1), while there was no significant difference in mechanical and thermal pain pain threshold recovery rates between 10-minute manual acupuncture group and 30-minute flurbiprofen cataplasm treatment group (P>0.05). The mast cell degranulation rate in 10-minute manual acupuncture group and the 30-minute flurbiprofen cataplasm treatment group was significantly higher than that of the model group (P<0.001).

Short-term application of manual acupuncture provides immediate analgesia in AA rats, comparable to flurbiprofen cataplasm treatment. The analgesic effects of manual acupuncture and flurbiprofen cataplasm treatment may be closely related to the degranulation of mast cells in the Zusanli acupoint tissue. This study provides an optimized clinical protocol for treating inflammatory joint diseases while laying the groundwork for future research on treatment mechanisms, long-term outcomes, and combination therapy applicability in varied patient groups.

To design and verify an implantable dialysis port that enables the central venous catheter to no longer be placed on the body surface, and to study the effect of the central venous catheter's structural design on its performance.

The feasibility of the dialysis port was verified by flow and pressure experiments. Four representative catheter structures were analyzed by finite element method. The recirculation rate, flow rate-pressure ratio and proportion of indwelling particles were recorded, and performance differences were analyzed. An experimental platform was built to verify the simulation conclusion, and the fluid flow direction of the arteriovenous cavity was quantified by the salinity measurement method.

The dialysis port could reach the flow requirement of 300 mL/min under the 45 kPa pressure. The recirculation rate of the measured central venous catheter was between 10.7% and 23.5%, and the residual value of heparin was between 2.3% and 2.8%. The performance of the catheter with bundle mouth, positive position and side hole structure was better.

The implantable dialysis port can potentially cooperate with central venous catheters to establish a new vascular access approach. The structure of the central venous catheter should adopt the design of bundle mouth, positive position and side hole, which has better recirculation rate and heparin locking performance with low flow rate-pressure ratio. This study provides a theoretical and experimental basis for structural design and clinical selection of the central venous catheter.