Due to the minimum antenna area constraints of synthetic aperture radar (SAR), high-resolution and wide-swath (HRWS) imaging is difficult to be achieved using classical modes, such as scan, spotlight, and so on. Range ambiguity is one of the main technical challenges limiting HRWS imaging in spaceborne SAR. Inspired by the cocktail party effect, an advanced scheme based on blind source separation (BSS) is put forward to suppress the range ambiguity of spaceborne SAR in this article. In the scheme, multiple subantennas are used to collect multiple echo datasets, which are given different patterns. In this way, the echo signal of the desired region and that of the ambiguous region are weighted using different coefficients. During postprocessing, a detailed flow with the BSS algorithm is proposed to separate the desired echoes from those datasets. To verify the scheme, point target and scene simulations based on GF-3 are carried out. The results indicate that the range ambiguity can be reduced by more than 15 dB using the proposed scheme, the processing flow is effective, and the scheme has a good performance without increasing the complexity of the system design under the current SAR system conditions. The scheme has the potential to be adopted in future spaceborne SAR missions.

In the bistatic synthetic aperture radar (BiSAR) system, the deviation between two oscillators in different platforms will cause an additional modulation of BiSAR echoes. Therefore, phase synchronization is one of the key issues that must be addressed for the BiSAR system. The oscillator phase error model and the principle of phase synchronization are firstly described. The waveform diversity technology has been widely used in many fields, for example, the hearing aids device and the recognition of auditory input source in cocktail party problem. Inspired by this, an advanced phase synchronization scheme based on coherent integration and waveform diversity is proposed. The synchronization signal and radar signal are orthogonal signals which can be separated by using waveform diversity technique. After extracting the synchronization signal, the phase synchronization accuracy can be further improved by coherent integration. The transmission of synchronization signals between two synchronization antennas is analyzed, followed by the theoretical error analysis. Then, the processing of separating the echo signal and synchronization signal is described in detail. The simulation experiments are performed. The accuracy of phase synchronization can reach 1 degree, which verifies the effectiveness of the proposed synchronization scheme.

Background: Telemedicine has demonstrated efficacy as a supplement to traditional in-person care when treating certain diseases. Nevertheless, more investigation is needed to comprehensively assess its potential as an alternative to in-person care and its influence on access to care. The successful treatment of short stature relies on timely and regular intervention, particularly in rural and economically disadvantaged regions where the disease is more prevalent. Objective: This study evaluated the clinical outcomes, health-seeking behaviors, and cost of telemedicine integrated into care for children with short stature in China. Methods: Our study involved 1241 individuals diagnosed with short stature at the pediatric outpatient clinic of Peking University Third Hospital between 2012 and 2023. Patients were divided into in-person care (IPC; 1183 patients receiving only in-person care) and telemedicine integrated care (TIC; 58 patients receiving both in-person and virtual care) groups. For both groups, the initial 71.43% (average of 58 percentages, with each percentage representing the ratio of patients in the treatment group) of visits were categorized into the pretelemedicine phase. We used propensity score matching to select individuals with similar baseline conditions. We used 7 variables such as age, gender, and medical insurance for the 1:5 closest neighbor match. Eventually, 115 patients in the IPC group and 54 patients in the TIC group were selected. The primary clinical outcome was the change in the standard height percentage. Health-seeking behavior was described by visit intervals in the pre- and post-telemedicine phases. The cost analysis compared costs both between different groups and between different visit modalities of the TIC group in the post-telemedicine phase. Results: In terms of clinical effectiveness, we demonstrated that the increase in height among the TIC group (ΔzTIC=0.74) was more substantial than that for the IPC group (ΔzIPC=0.51, P=.01; paired t test), while no unfavorable changes in other endpoints such as BMI or insulin-like growth factor 1 (IGF-1) levels were observed. As for health-seeking behaviors, the results showed that, during the post-telemedicine phase, the IPC group had a visit interval of 71.08 (IQR 50.75-90.73) days, significantly longer than the prior period (51.25 [IQR 34.75-82.00] days, P<.001; U test), whereas the TIC group’s visit interval remained unchanged. As for the cost per visit, there was no difference in the average cost per visit between the 2 groups nor between the pre- and post-telemedicine phases. During the post-telemedicine phase, within the TIC group, in-person visits had a higher average total cost, elevated medical and labor expenses, and greater medical cost compared with virtual visits. Conclusions: We contend that the rise in medical visits facilitated by integrating telemedicine into care effectively restored the previously constrained number of medical visits to their usual levels, without increasing costs. Our research underscores that administering prompt treatment may enable physicians to seize a crucial treatment opportunity for children with short stature, thus attaining superior results.

Background: Telemedicine is developing rapidly, presenting new opportunities and challenges for physicians and patients. Limited research has examined physicians’ behavior during the process of adopting telemedicine and related factors. Objective: This study aimed to identify perceived barriers and enablers of physicians’ adoption of telemedicine and to develop intervention strategies. Methods: Three interlinked frameworks, the Theoretical Domains Framework (TDF), the Behavior Change Wheel (BCW), and behavior change techniques (BCTs), were used sequentially to identify the factors for physicians’ telemedicine adoption and to develop intervention strategies. First, guided by the TDF, a questionnaire was developed and administered in interviews with 36 physicians from 29 different medical institutions in Beijing. Second, the content of the semistructured physician interviews was analyzed using the software NVivo 12.0 to extract themes under each domain. Each theme was then classified as either a barrier or an enabler based on the physicians’ language and expression. Third, following the established relationships in the literature, we mapped each domain in the TDF to the corresponding intervention functions and policy categories within BCW. Fourth, for each identified intervention function, we further identified the associated BCTs using the standardized mappings reported in previous studies. The process of identifying intervention functions, policy categories, and techniques was guided by the APEASE (acceptability, practicability, effectiveness, affordability, spill-over effects, and equity) criteria. Last, potential implementation strategies were proposed via focus group discussion. Results: We identified 50 themes in relation to the adoption of telemedicine. These comprised 27 barriers and 23 enablers, ranging from administrative issues to specific clinical conditions. Of the 14 TDF domains, 11 domains were mentioned. The most frequently mentioned domains were environmental context and resources (10 themes), beliefs about consequences (9 themes), and emotion (7 themes). Major barriers comprised limited acceptance among senior physicians, inconsistent system performance, inadequate platform usability, and inadequate medical insurance coverage. Key enablers included sufficient communication skills and proficiency in system operations, together with the conviction that telemedicine may assist patients with resolving medical issues and prompt support from the IT department when challenges arise. Additionally, 7 of 9 intervention functions, 6 of 7 policy categories, and 26 of 93 BCTs were selected for each theme. Finally, we proposed several potential implementation strategies to enhance physician adoption of telemedicine. Conclusions: This study identified a range of interventions and strategies that could improve telemedicine adoption in this context. Implementing these measures requires efforts from health administrative departments, medical institutions, and health care personnel.

Automatic radiology report generation has gained increasing attention for its potential to assist in clinical reporting and reduce the workload of radiologists. Existing 3D radiology report generation methods employ multi-modal foundation model to encode volume-text inputs and produce diagnosis reports, while they ignore the characteristics of 3D volumes including much background regions and suffer from generating hallucinations, especially in medical domain that contains many uncommon professional terms. In this paper, we aim to efficiently adapt the pre-trained foundation model to specific 3D radiology report generation, and present a Prior-drIven Prompting with diagnosis-oriented retrieval-Augmentation (PIPA) framework. In PIPA, we design a Prior-drIven Prompting (PIP) strategy to exploit diagnostic knowledge from input volumes and a Diagnosis-oriented volume-report retrievalaugmentation Generation (DIG) module to explore beneficial knowledge from external database. Specifically, in PIP, to take full advantage of the patient's clinical information, e.g., age and symptoms, and the possible disease information, e.g., brain tumor, edema, we formulate them as the patient and disease priors to mine clinical relevant knowledge. Furthermore, we propose utilizing visual and textual embeddings as queries to retrieve similar external data by devising a diagnosis-oriented retrieval-augmentation scheme for leveraging more report resources as references for LLM to produce accuracy outcomes. With PIP and DIG, PIPA integrates clinical priors and external data to learn effective diagnostic representations for high-quality report generation. We evaluate the framework on both public and in-house 3D medical datasets with corresponding reports, demonstrating its strong performance in generating accurate diagnosis reports. Source codes have been published at https://github.com/CUHK-AIM-Group/PIPA/tree/ main.

Background: Telemedicine has rapidly expanded worldwide due to its convenience and accessibility. In China, an increasing number of hospitals have begun offering telemedicine services; however, patient utilization remains relatively low. Limited research has examined patients’ behaviors during the process of adopting telemedicine services. Objective: This study aimed to identify barriers to and enablers for patients using telemedicine services and to formulate implementation strategies. Methods: We conducted semistructured qualitative interviews based on the Theoretical Domains Framework (TDF) to identify barriers and enablers to telemedicine utilization. Twenty-one patients who had used Peking University Third Hospital’s telemedicine services were included in the interviews. Data were analyzed using NVivo 12.0 with deductive thematic analysis guided by the TDF. Moreover, a group of experts was assembled to devise potential intervention strategies. Results: A total of 28 themes were identified, including 14 barriers and 14 enablers across 5 of the 14 TDF domains. The most frequently reported barriers were operational challenges, prolonged waiting periods from asynchronous communication, and doubts about therapeutic efficacy, whereas the most frequently mentioned enablers were the convenience of telemedicine, time conservation, and support from hospitals. On the basis of these factors, we devised 6 intervention strategies. Conclusions: This study demonstrated that patients’ utilization of telemedicine services was affected by several barriers and enablers, including system architecture and design, patient interactions using telemedicine, and external assistance. To enhance the utilization, these factors must be meticulously considered. This study also suggests strategies to enhance the utilization of telemedicine.