Magnetic Stirring Device for Limiting the Sedimentation of Cells inside Microfluidic Devices.

In experiments considering cell handling in microchannels, cell sedimentation in the storage container is a key problem because it affects the reproducibility of the experiments. Here, a simple and low-cost cell mixing device (CMD) is presented; the device is designed to prevent the sedimentation of cells in a syringe during their injection into a microfluidic channel. The CMD is based on a slider crank device made of 3D-printed parts that, combined with a permanent magnet, actuate a stir bar placed into the syringe containing the cells. By using A549 cell lines, the device is characterized in terms of cell viability (higher than 95%) in different mixing conditions, by varying the oscillation frequency and the overall mixing time. Then, a dedicated microfluidic experiment is designed to evaluate the injection frequency of the cells within a microfluidic chip. In the presence of the CMD, a higher number of cells are injected into the microfluidic chip with respect to the static conditions (2.5 times), proving that it contrasts cell sedimentation and allows accurate cell handling. For these reasons, the CMD can be useful in microfluidic experiments involving single-cell analysis.

Development of real-time navigation system for laparoscopic hepatectomy using magnetic micro sensor.

BACKGROUND: We report a new real-time navigation system for laparoscopic hepatectomy (LH), which resembles a car navigation system. MATERIAL AND METHODS: Virtual three-dimensional liver and body images were reconstructed using the "New-VES" system, which worked as roadmap during surgery. Several points of the patient's body were registered in virtual images using a magnetic position sensor (MPS). A magnetic transmitter, corresponding to an artificial satellite, was placed about 40 cm above the patient's body. Another MPS, corresponding to a GPS antenna, was fixed on the handling part of the laparoscope. Fiducial registration error (FRE, an error between real and virtual lengths) was utilized to evaluate the accuracy of this system. RESULTS: Twenty-one patients underwent LH with this system. Mean FRE of the initial five patients was 17.7 mm. Mean FRE of eight patients in whom MDCT was taken using radiological markers for registration of body parts as first improvement, was reduced to 10.2 mm (p = .014). As second improvement, a new MPS as an intraoperative body position sensor was fixed on the right-sided chest wall for automatic correction of postural gap. The preoperative and postoperative mean FREs of 8 patients with both improvements were 11.1 mm and 10.1 mm (p = .250). CONCLUSIONS: Our system may provide a promising option that virtually guides LH.

Single-molecule multiplexed profiling of protein-DNA complexes using magnetic tweezers.

Epigenetics, such as the dynamic interplay between DNA methylation and demethylation, play diverse roles in critical cellular events. Enzymatic activity at CpG sites, where cytosines are methylated or demethylated, is known to be influenced by the density of CpGs, methylation states, and the flanking sequences of a CpG site. However, how the relevant enzymes are recruited to and recognize their target DNA is less clear. Moreover, although DNA-binding epigenetic enzymes are ideal targets for therapeutic intervention, these targets have been rarely exploited. Single-molecule techniques offer excellent capabilities to probe site-specific protein-DNA interactions and unravel the dynamics. Here, we develop a single-molecule approach that allows multiplexed profiling of protein-DNA complexes using magnetic tweezers. When a DNA hairpin with multiple binding sites is unzipping, strand separation pauses at the positions bound by a protein. We can thus measure site-specific binding probabilities and dissociation time directly. Taking the TET1 CXXC domain as an example, we show that TET1 CXXC binds multiple CpG motifs with various flanking nucleotides or different methylation patterns in an AT-rich DNA. We are able to establish for the first time, at nanometer resolution, that TET1 CXXC prefers G/C flanked CpG motif over C/G, A/T, or T/A flanked ones. CpG methylation strengthens TET1 CXXC recruitment but has little effect on dissociation time. Finally, we demonstrate that TET1 CXXC can distinguish five CpG clusters in a CpG island with crowded binding motifs. We anticipate that the feasibility of single-molecule multiplexed profiling assays will contribute to the understanding of protein-DNA interactions.

Remote magnetic navigation versus manual catheter ablation of atrial fibrillation: A single center long-term comparison.

BACKGROUND: Data comparing remote magnetic catheter navigation (RMN) with manual catheter navigation (MCN) ablation of atrial fibrillation (AF) is lacking. The aim of the present prospective observational study was to compare the outcome of RMN versus (vs.) MCN ablation of AF with regards to AF recurrence. METHODS: The study comprised 667 consecutive patients with a total of 939 procedures: 287 patients were ablated using RMN, 380 using MCN. RESULTS: There was no significant difference between the groups at baseline. After 2.3 ± 2.3 years of follow-up, 23% of the patients in the MCN group remained free of AF recurrence compared to 13% in the RMN group (p < .001). After analysis of 299 repeat ablations (133 MCN, 166 RMN) there was a significantly higher reconnection rate of pulmonary veins after RMN ablation p < .001). In multivariable Cox-regression analysis, RMN ablation was an independent risk factor for AF recurrence besides age, persistent AF, number of isolated pulmonary veins, and left atrial diameter. Procedure time, radiofrequency application time and total number of ablation points were higher in the RMN group. Total fluoroscopy time and total fluoroscopy dose were significantly lower for RMN. Complication rates did not differ between groups (p = .842), although the incidence of significant pericardial effusion was higher in the MCN group (seven cases vs. three in RMN group). CONCLUSIONS: In our study the AF recurrence rate and pulmonary vein reconnection rate is higher after RMN ablation with a similar complication rate but reduced probability of pericardial effusion when compared to MCN.

Solid-phase extraction methods for nucleic acid separation. A review.

The separation and purification of biomacromolecules such as nucleic acid is a perpetual topic in separation processes and bioengineering (fine chemicals, biopharmaceutical engineering, diagnostics, and biological characterization). In principle, the solid-phase extraction for nucleic acid exhibits efficient phase separation, low pollution risk, and small sample demand, compared to the conventional liquid-phase extraction. Herein, solid-phase extraction methods are systematically reviewed to outline research progress and explore additional solid-phase sorbents and devices for novel, flexible, and high-efficiency nucleic acid separation processes. The functional materials capture nucleic acid, magnetic and magnetic-free solid-phase extraction methods, separation device design and optimization, and high-throughput automatable applications based on high-performance solid-phase extraction are summarized. Finally, the current challenges and promising topics are discussed.

Hydrophilic molecularly imprinted polymers functionalized magnetic carbon nanotubes for selective extraction of cyclic adenosine monophosphate from winter jujube.

In this work, a green strategy was developed to prepare molecularly imprinted polymers functionalized magnetic carbon nanotubes in aqueous phase under mild conditions for cyclic adenosine monophosphate. Thanks to water solubility of chitosan, a natural polysaccharide which is rich in amino and hydroxyl groups, provided the feasibility to synthesize the green molecularly imprinted polymers for water soluble template in aqueous media. Coupled with high-performance liquid chromatography, the method exhibited a short equilibrium time (6 min), high adsorption capacity (22.42 µg/mg), high magnetic susceptibility, and good selectivity to template molecule with the imprinting factor of 2.94. A good linearity in the range of 0.020-3.0 mg/mL for target was obtained with a correlation coefficient of 0.9998. The limit of detection (signal-to-noise ratio = 3) and limit of quantitation (signal-to-noise ratio = 10) of the magnetic solid phase extraction method for cyclic adenosine monophosphate were 5 and 15 ng/mg, respectively. And the practical application of chitosan-based molecularly imprinted polymers as adsorbent to isolate and determine cyclic adenosine monophosphate in real natural samples (winter jujube) was demonstrated.

Extraction of human noroviruses from leafy greens and fresh herbs using magnetic silica beads.

Consumption of leafy greens and to a lesser extent fresh herbs has been associated with several foodborne outbreaks including human norovirus (HuNoV). However, the extraction and detection of viruses from these matrices present multiple challenges such as low recovery yields and relatively high PCR inhibition. A new magnetic silica bead based (MSB) extraction protocol was developed and used to recover norovirus from leafy greens and fresh herbs. The performance results were compared to the ISO 15216-1:2017 standard. The HuNoV GII.4 and GI.5 recovery yields from spiked lettuce using the MSB extraction protocol range from 33 to 82%. There was a good correlation between murine norovirus (MNV) and HuNoV recovery yields from fresh herbs and leafy greens. No reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR) inhibition was detected from leafy green extracts using the MSB methodology. The selected commercial RT-qPCR detection kit had a major impact on RT-qPCR inhibition levels detected in the ISO 15216-1:2017 RNA extracts. RNase treatment was used to estimate genome recovery from HuNoV with intact capsids. This treatment resulted in similar HuNoV and MNV recovery yields. Between 2019 and 2020, the MSB protocol was used to conduct a survey of HuNoV in domestic and imported leafy greens and fresh herbs sold at retail in Canada. All of the 280 samples tested were negative. Overall, the use of MSB was shown to be an efficient approach to recover HuNoV from leafy greens and certain types of fresh herbs and to conduct surveys.

Opposite Effects of High-Valent Cations on the Elasticities of DNA and RNA Duplexes Revealed by Magnetic Tweezers.

We report that trivalent cobalt hexammine cations decrease the persistence length, stretching modulus, helical density, and size of plectonemes formed under torque of DNA but increase those of RNA. Divalent magnesium cations, however, decrease the persistence lengths, contour lengths, and sizes of plectonemes while increasing the helical densities of both DNA and RNA. The experimental results are explained by different binding modes of the cations on DNA and RNA in our all-atom molecular dynamics simulations. The significant variations of the helical densities and structures of DNA and RNA duplexes induced by high-valent cations may affect interactions of the duplexes with proteins.

Synergistic use of electroosmotic flow and magnetic forces for nucleic acid extraction.

Nucleic acid sample preparation is essential for biological sample-based diagnostics. It is crucial that diagnostic tests be both specific and sensitive as to provide the most accurate diagnosis possible. Inefficient sample preparation can hinder the specificity and sensitivity of these tests since carryover contaminants can inhibit downstream processes, such as amplification. Microfluidic devices have been used previously to extract nucleic acids from a biological sample due to lower reagent volumes and ease of use. A novel microfluidic chip has been designed for nucleic acid sample preparation which combines electroosmotic flow and magnetic bead-based extraction to isolate DNA from a plasma sample. A steady electric field was incorporated into the microfluidic chip design, which when combined with a glass clover slip and a voltage differential, creates electroosmotic flow. With the goal of isolating nucleic acids into a clean, inhibitor free solution, the electroosmotic flow is the driving force and separation mechanism purifying the DNA sample captured on magnetic beads in the microfluidic chip system. Carryover volume, or the volume of unwanted sample contaminants that accompany the nucleic acids into the final elution buffer, was minimized to 0.22 ± 0.03%. In combination with magnetic bead based nucleic acid extraction techniques, a 15% increase in DNA extraction yield is reported for the microfluidic chip with the voltage applied versus without. Although the literature on nucleic acid separation in microfluidic chips is abundant, this is the first to combine microfluidic chip design, magnetic bead-based isolation and electroosmotic flow.

Magnetic nanowires in biomedical applications.

Magnetic nanostructures and nanomaterials play essential roles in modern bio medicine and technology. Proper surface functionalization of nanoparticles (NPs) allows the selective bonding thus application of magnetic forces to a vast range of cellular structures and biomolecules. However, the spherical geometry of NPs poises a series of limitations in various potential applications. Mostly, typical spherical core shell structure consists of magnetic and non-magnetic layers have little tunability in terms of magnetic responses, and their single surface functionality also limits chemical activity and selectivity. In comparison to spherical NPs, nanowires (NWs) possess more degrees of freedom in achieving magnetic and surface chemical tenability. In addition to adjustment of magnetic anisotropy and inter-layer interactions, another important feature of NWs is their ability to combine different components along their length, which can result in diverse bio-magnetic applications. Magnetic NWs have become the candidate material for biomedical applications owing to their high magnetization, cheapness and cost effective synthesis. With large magnetic moment, anisotropy, biocompatibility and low toxicity, magnetic NWs have been recently used in living cell manipulation, magnetic cell separation and magnetic hyperthermia. In this review, the basic concepts of magnetic characteristics of nanoscale objects and the influences of aspect ratio, composition and diameter on magnetic properties of NWs are addressed. Some underpinning physical principles of magnetic hyperthermia (MH), magnetic resonance imaging (MRI) and magnetic separation (MS) have been discussed. Finally, recent studies on magnetic NWs for the applications in MH, MRI and MS were discussed in detail.

Self-assembly of poly(ionic liquid) functionalized mesoporous magnetic microspheres for the solid-phase extraction of preservatives from milk samples.

In this work, a novel, rapid, and simple analytical method was proposed for the detection of parabens in milk sample by gas chromatography coupled with mass spectrometry. At the same time, milk sample was pretreated by magnetic solid phase extraction, which detected up to five parabens. A series of important parameters of magnetic solid phase extraction were investigated and optimized, such as pH value of loading buffer, amount of material, adsorption time, ionic strength, eluting solvents, and eluting time. Under the optimized conditions, the corresponding values were more than 0.9991, limits of detection and the limit of quantification were 0.1 and 0.5 ng/mL, respectively. In addition, the recoveries were achieved in range of 95-105%, the liner range were within 0.1-600 ng/mL, and the relative standard deviations were even lower than 5%.

Design of a Fully Integrated Inductive Coupling System: A Discrete Approach Towards Sensing Ventricular Pressure.

In this paper, an alternative strategy for the design of a bidirectional inductive power transfer (IPT) module, intended for the continuous monitoring of cardiac pressure, is presented. This new integrated implantable medical device (IMD) was designed including a precise ventricular pressure sensor, where the available implanting room is restricted to a 1.8 × 1.8 cm2 area. This work considers a robust magnetic coupling between an external reading coil and the implantable module: a three-dimensional inductor and a touch mode capacitive pressure sensor (TMCPS) set. In this approach, the coupling modules were modelled as RCL circuits tuned at a 13.56 MHz frequency. The analytical design was validated by means of Comsol Multiphysics, CoventorWare, and ANSYS HFSS software tools. A power transmission efficiency (PTE) of 94% was achieved through a 3.5 cm-thick biological tissue, based on high magnitudes for the inductance (L) and quality factor (Q) components. A specific absorption rate (SAR) of less than 1.6 W/Kg was attained, which suggests that this IPT system can be implemented in a safe way, according to IEEE C95.1 safety guidelines. The set of inductor and capacitor integrated arrays were designed over a very thin polyimide film, where the 3D coil was 18 mm in diameter and approximately 50% reduced in size, considering any conventional counterpart. Finally, this new approach for the IMD was under development using low-cost thin film manufacturing technologies for flexible electronics. Meanwhile, as an alternative test, this novel system was fabricated using a discrete printed circuit board (PCB) approach, where preliminary electromagnetic characterization demonstrates the viability of this bidirectional IPT design.

Dynamic Analysis of Sphere-Like Iron Particles Based Magnetorheological Damper for Waveform-Generating Test System.

In this study, a new double pulse waveform-generating test system with an integrated magnetorheological (MR) damper is proposed. Since the total shear stress of MR fluid can be varied according to the shape of particles, sphere-like iron particles-based MR fluid is filled into the MR damper. The test system consists of a velocity generator, three masses (impact, test, and dummy), a spring, and an MR damper. To tune the double pulse waveform profile, a damping force model is constructed to determine the fundamental parameters of the simulator. Then, the first and second shock waveform profiles are analyzed to solve the governing equation of motions representing the damping force and velocity. The mathematical model of the MR damper is formulated and applied to a simulator with a graphical user interface programmed using MATLAB. The effectiveness of the proposed simulator-featuring controllable MR damper is demonstrated by comparing the simulation and experimental results.

Improving the Sensitivity of Fluorescence-Based Immunoassays by Photobleaching the Autofluorescence of Magnetic Beads.

In fluorescence-based assays, usually a target molecule is captured using a probe conjugated to a capture surface, and then detected using a second fluorescently labeled probe. One of the most common capture surfaces is a magnetic bead. However, magnetic beads exhibit strong autofluorescence, which often overlaps with the emission of the reporter fluorescent dyes and limits the analytical performance of the assay. Here, several widely used magnetic beads are photobleached and their autofluorescence is reduced to 1% of the initial value. Their autofluorescence properties, including their photobleaching decay rates and autofluorescence spectra pre- and post-photobleaching, and the stability of the photobleaching over a period of two months are analyzed. The photobleached beads are stable over time and their surface functionality is retained. In a high-sensitivity LX-200 system using photobleached magnetic beads, human interleukin-8 is detected with a threefold improvement in detection limit and signal-to-noise ratio over results achievable with nonbleached beads. Since many contemporary immunoassays rely on magnetic beads as capture surfaces, prebleaching the beads may significantly improve the analytical performance of these assays. Moreover, nonmagnetic beads with low autofluorescence are also successfully photobleached, suggesting that photobleaching can be applied to various capture surfaces used in fluorescence-based assays.

Evaluation of a Ferromagnetic Marker Technology for Intraoperative Localization of Nonpalpable Breast Lesions.

OBJECTIVE: The purpose of this study was to evaluate the magnetic occult lesion localization instrument (MOLLI) system that involves implantation of a small, ferromagnetic marker to guide surgical excision of nonpalpable breast lesions. Characterization of the system was undertaken as part of what is, to our knowledge, the first study to assess the MOLLI system. MATERIALS AND METHODS: The MOLLI system consists of a handheld probe that can detect the position and distance of an implanted magnetic marker. The system presents the surgeon with an accurate assessment of lesion location and depth measurement for precise 3D localization. The marker is implanted under ultrasound or mammographic guidance at any time before the surgical procedure and requires no special precautions. Experimental analysis focused on characterization of the following aspects of the MOLLI system: visualization of the marker under imaging, 3D detection of the magnetic marker, spatial resolution of the probe to detect markers placed in close proximity, and the effect of signal interference on system performance. RESULTS: The MOLLI system can reliably detect mean (± SD) marker depths up to 53 ± 8.56 mm from the probe. Bracketing large lesions or localizing multiple lesions can be accomplished by placing markers as close as 10 mm apart, at depths of up to 42 mm. The biologically inert MOLLI marker is readily visible under ultrasound and mammographic guidance, and it is differentiable from radiologic clips. The effect of surgical instruments on MOLLI functioning is minimal and does not impact system accuracy or reliability. CONCLUSION: The MOLLI system offers an accurate and efficient alternative lesion localization method for nonpalpable breast lesions.

Enantioseparation of chiral ß-blockers using polynorepinephrine-coated nanoparticles and chiral capillary electrophoresis.

A method of combining magnetic solid-phase separation (MSPE) and chiral capillary electrophoresis (CE) is developed for enantioseparation of trace amounts of ß-blockers. Polynorepinephrine-functionalized magnetic nanoparticles (polyNE-MNPs) are synthesized and applied to simultaneously extract three ß-blockers (carteolol, metoprolol, and betaxolol). The prepared polyNE-MNPs are spherical with a diameter of 198 ± 17 nm and the thickness of the polyNE coating is about 14 nm. PolyNE possesses abundant catechol hydroxyl and secondary amine groups, endowing the MNPs with excellent hydrophilicity. Under the optimum conditions, the extraction efficiencies of polyNE-MNPs for ß-blockers are in the range of 89.6 to 100%, with relative standard deviations (RSDs) below 3.5%. The extraction process can be finished in 4 min. Field-enhanced sample injection (FESI) in chiral CE is constructed to further enhance the sensitivities of ß-blocker enantiomers. The limits of detection for ß-blocker enantiomers by the FESI-CE with polyNE-MNPs are in the range of 0.401 to 1.59 ng mL-1. The practicability of this method in real samples is evaluated by analysis of human urine samples. The recoveries for each enantiomer of ß-blockers in the real samples range from 89.5 to 92.8%, with RSDs ranging from 0.37 to 5.9%. The whole detection process can be finished in less than 0.5 h. The method demonstrates its great potential in the pharmacokinetic and pharmacodynamic studies of chiral drugs in humans. Graphical abstract ᅟ.

Magnetic Steering of Capsule Endoscopy Improves Small Bowel Capsule Endoscopy Completion Rate.

BACKGROUND: Capsule endoscopy is currently available as a noninvasive and effective diagnostic modality to identify small bowel abnormalities, with a completion rate to the cecum between 75.1 and 95.6%. A novel magnetically controlled capsule endoscopy (MCE) system could facilitate passage of the capsule through the pylorus, thereby reducing the gastric transit time (GTT). OBJECTIVE: We performed this study to determine whether magnetic steering could improve the capsule endoscopy completion rate (CECR) compared to standard protocol. METHODS: Patients referred for MCE in our center from June 2017 to November 2017 were prospectively enrolled. Magnetic steering of the capsule through the pylorus was performed after standard gastric examination. CECR, GTT, pyloric transit time (PTT), and rapid gastric transit (GTT ≤ 30 min) rate were compared with a historical control group enrolled from January 2017 to May 2017. RESULTS: CECR was significantly higher in the intervention group (n = 107) than control group (n = 120) (100% vs. 94.2%, P = 0.02), with a significantly shorter GTT (22.2 vs. 84.5 min, P < 0.001) and PTT (4.4 vs. 56.7 min, P < 0.001). Rapid gastric transit rate in the intervention group was significantly higher than the control group (58.9% vs. 15.0%, P < 0.001). There were no statistical differences in the diagnostic yields between the two groups. CONCLUSIONS: Magnetic steering of capsule endoscopy improves small bowel CECR by reducing GTT, adding further support to MCE as a practical tool for noninvasive examination of both the stomach and small bowel. Trial registration ClinicalTrials.gov, ID: NCT03482661.

Application of magnetized MOF-74 to phthalate esters extraction from Chinese liquor.

In this study, magnetized MOF-74 (Ni) was prepared using an ultrasound-assisted synthesis method. This novel functional magnetic adsorbent was characterized using various techniques. Using the prepared material as adsorbents, a magnetic solid-phase extraction method coupled with high-performance liquid chromatography was proposed for determining four phthalate esters in Chinese liquor samples. The extraction parameters, including solution pH, adsorbent amount, extraction time, and eluent type and volume, were optimized. Under the optimized conditions, proposed method showed good linearity within the range of 1.53-200 µg/L for diphenyl phthalate, 2.03-200 µg/L for butyl benzyl phthalate, 7.02-200 µg/L for diamyl phthalate, and 6.03-200 µg/L for dicyclohexyl phthalate, with correlation coefficients > 0.9944, low limits of detection (0.46-2.10 µg/L, S/N = 3), and good extraction repeatability (relative standard deviations of 3.7%, n = 6). This method was successfully used to analyze phthalate esters in Chinese liquor samples with recoveries of 74.4-104.8%. Two phthalate esters were detected in two samples, both at concentrations that satisfied the Chinese national standard, indicating this method has practical application prospects. The extraction efficiency of this method was also compared with conventional solid-phase extraction using commercial C18 cartridges. The results demonstrated that the proposed magnetic solid-phase extraction is a simple, time-saving, efficient, and low-cost method.

Magnetic mesoporous polyimide composite for efficient extraction of Rhodamine B in food samples.

A core-shell structured magnetic polyimide composite has been synthesized by the covalent coating of a mesoporous polyimide polymer onto the surface of magnetite nanoparticles. The nanocomposite was characterized by scanning electron microscopy, transmission electron microscopy, N2 adsorption-desorption isotherms, X-ray diffraction, infrared spectroscopy, and vibrating sample magnetometry. The results showed that the prepared composite had a large surface area (306.45 m²/g), a unique pore size (2.15 nm), and strong magnetic properties (45.7 emµ/g), rendering it a promising sorbent material for magnetic solid-phase extraction. The parameters that affect the extraction efficiency of rhodamine B were optimized with the assistance of response surface methodology. Under the optimal conditions, the developed method has been successfully applied to determine the rhodamine B in food samples. The linearities and limits of detection of rhodamine B in hot pepper, red wine, and chili powder samples were measured. Satisfactory recoveries in the range of 94.8-103.3% with relative standard deviations <5.5% were obtained. Investigation of the adsorption mechanism of magnetic polyimide composite indicated that multiple interactions, including hydrophobic, π-π, and hydrogen bonding interactions, were involved in the adsorption process.

Mechanical antithrombogenic properties by vibrational excitation of the impeller in a magnetically levitated centrifugal blood pump.

Mechanical circulatory support devices have been used clinically for patients with heart failure for over 10 years. However, thrombus formation inside blood pumps remains a risk to patient life, causing pump failure and contributing to neurological damage through embolization. In this article, we propose a method for preventing thrombus formation by applying vibrational excitation to the impeller. We evaluate the ability of this method to enhance the antithrombogenic properties of a magnetically levitated centrifugal blood pump and ensure that the impeller vibration does not cause undue hemolysis. First, 3 vibrational conditions were compared using an isolated pump without a mock circulation loop; the vibrational excitation frequencies and amplitudes for the impeller were set to (a) 0 Hz-0 µm, (b) 70 Hz-10 µm, and (c) 300 Hz-2.5 µm. The motor torque was measured to detect thrombus formation and obtain blood coagulation time by calculating the derivative of the torque. Upon thrombus detection, the pump was stopped and thrombi size were evaluated. The results showed an increase in the blood coagulation time and a decrease in the rate of thrombus formation in pumps with the impeller vibration. Second, an in vitro hemolysis test was performed for each vibrational condition to determine the effect of impeller vibration on hemolysis. The results revealed that there was no significant difference in hemolysis levels between each condition. Finally, the selected vibration based on the above test results and the non-vibration as control were compared to investigate antithrombogenic properties under the continuous flow condition. The blood coagulation time and thrombi size were investigated. As a result, vibrational excitation of the impeller at a frequency of 300 Hz and amplitude of 2.5 µm was found to significantly lengthen clotting time, decreasing the rate of pump thrombus compared to the non-vibration condition. We indicate the potential of impeller vibration as a novel mechanical antithrombogenic mechanism for rotary blood pumps.