https://scholar.dgist.ac.kr/handle/20.500.11750/171 2026-04-04T06:47:38Z https://scholar.dgist.ac.kr/handle/20.500.11750/60062 Title: Open-Loop Position Control of a Miniature Magnetic Robot Using Two-Dimensional Divergence Control of a Magnetic Force Author(s): Lee, Hakjoon; Gharamaleki, Nader Latifi; Choi, Hongsoo Abstract: Miniature magnetic robots have attracted considerable attention as promising tools in biomedical applications due to their wireless actuation and precise controllability in a minimally invasive manner. Traditionally, magnetic microrobots have been controlled by globally applied magnetic torques and forces generated by external magnetic actuation systems (MASs), which typically require closed-loop control with real-time vision tracking - a challenging requirement in in-vivo environments. To address this issue, this paper suggests a novel open-loop control scheme for magnetic robots, using two-dimensional (2D) divergence control of a magnetic force generated by stationary electromagnets. Constraint equations for the currents applied to the electromagnets were established to achieve 2D divergence control of a magnetic force. Numerical simulation and experimental validations demonstrate that this approach can generate sufficient magnetic forces that either converge at or diverge from a target point, enabling effective open-loop position control of a miniature magnetic robot. Due to the absence of vision feedback and mechanical motions of magnets, the proposed control strategy could be more clinically applicable for medical applications of magnetic robots. 2025-05-18T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59929 Title: Translational reprogramming of dentate gyrus peptidergic circuitry gates antidepressant efficacy Author(s): Seo-Jin Oh; Jin-jyeok Jang; Jean-Pierre Roussarie; Gyeong-un Jang; Min-seok Jeong; Yeon Suk Jo; Chang-Hoon Shin; Hongsoo Choi; Kwang Lee; Yoon, Jong-Hyeok; Yong-Seok Oh Abstract: Selective serotonin reuptake inhibitors (SSRIs) exhibit delayed therapeutic effects despite rapid serotonin elevation, suggesting their dependence on slow neuroplastic adaptations. Here, we demonstrate that antidepressant actions require cell type-specific translational regulation of the peptidergic signaling in the dentate gyrus (DG). Chronic, but not acute, treatment with an SSRI fluoxetine (FLX) selectively enhances translational activity in hilar mossy cells (MCs), with no detectable changes in neighboring granule cells (GCs). Combining Translating Ribosome Affinity Purification (TRAP) with RNA sequencing revealed distinct baseline translatomes between these two glutamatergic neurons and identified FLX-induced remodeling of peptidergic pathways in the DG. Crucially, we discovered MC-specific enrichment of the neuropeptide PACAP, which undergoes translation-dependent upregulation by chronic FLX treatment. This PACAP induction mediates neuroadaptive plasticity in PAC1 receptor-expressing GCs and drives behavioral responses prominently in female mice during prolonged FLX administration. Our findings establish cell type-specific translational reprogramming as a novel mechanistic framework for antidepressant action. https://scholar.dgist.ac.kr/handle/20.500.11750/59859 Title: 곡선형 자기코어를 갖는 자기 구동 시스템 Author(s): Abbasi Sarmad Ahmad; 최홍수; Chowdhury A M Masum Bulbul; Latifi Gharamaleki Nader; Ahmed Awais; 이학준; 김진영 Abstract: 본 발명은 공급되는 전류를 통해 자기장 또는 자기력을 형성하여 치료용 자기 구동 로봇 제어하는 곡선형 자기코어를 구비한 자기 구동 시스템으로서, 배치 공간부에 정렬되는 복수의 전자석을 포함하는 전자석 어레이를 포함하고, 상기 복수의 전자석 각각은 자기코어와 상기 자기코어를 둘러싸고 권취된 코일을 포함하여 직선형으로 연장된 전자석 몸체와, 상기 전자석 몸체로부터 돌출되도록 상기 자기코어로부터 연장 형성된 자기코어 선단부를 포함하며, 상기 복수의 전자석의 상기 자기코어 선단부들은 타겟 위치를 향하여 구부려져 배향된, 곡선형 자기코어를 구비한 자기 구동 시스템을 제공한다. https://scholar.dgist.ac.kr/handle/20.500.11750/59397 Title: Dual Active Tilted Roller Actuation System (DATRAS) with an electromagnetic actuation system for vascular intervention Author(s): Chowdhury, A. M. Masum Bulbul; Gharamaleki, Nader Latifi; Lee, Hakjoon; Kim, Jin-Young; Kim, Minsoo; Vidal, Salvador Pane i Vidal; Youn, Sung Won; Choi, Hongsoo Abstract: This paper presents DATRAS (Dual Active Tilted Roller Actuation System), a compact robotic system for vascular interventions that integrates with electromagnetic actuation systems to enable complete teleoperation. DATRAS combines translation and rotation motion for intervention tools in a single module, simplifying design and control. The system also allows easy roller adjustment for various tool diameters and enables guidewire helical motion without additional components or specialized guidewires. Experimental validation using cerebrovascular and cardiovascular phantoms demonstrates DATRAS’s effectiveness in controlling magnetic tip guidewire motion when combined with electromagnetic actuation. Weighing just 320 g, this lightweight device aims to enhance interventional procedures by facilitating easy manipulation of instruments through teleoperation. The actuator addresses current limitations in robotic intervention systems, exhibiting a potential reduction in radiation exposure and ergonomic risks for medical professionals, ultimately improving the efficacy of vascular interventions. 2025-03-31T15:00:00Z