Hybrid Magnetic Force and Torque Actuation of Miniature Helical Robots Using Mobile Coils to Accelerate Blood Clot Removal

2021 ◽  
Author(s):  
Lidong Yang ◽  
Moqiu Zhang ◽  
Haojin Yang ◽  
Zhengxin Yang ◽  
Li Zhang
Keyword(s):  
Magnetic Force ◽  
Blood Clot ◽  
Clot Removal

scholarly journals Feasibility of Crosslinked Acrylic Shape Memory Polymer for a Thrombectomy Device

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Andrea D. Muschenborn ◽  
Keith Hearon ◽  
Brent L. Volk ◽  
Jordan W. Conway ◽  
Duncan J. Maitland
Keyword(s):  
Crosslink Density ◽  
Blood Clot ◽  
Shape Memory Polymer ◽  
Thermomechanical Properties ◽  
Recovery Stress ◽  
Element Analysis ◽  
Clot Removal ◽  
Acrylic Copolymers ◽  
Thrombectomy Device ◽  
And Performance

Purpose. To evaluate the feasibility of utilizing a system of SMP acrylates for a thrombectomy device by determining an optimal crosslink density that provides both adequate recovery stress for blood clot removal and sufficient strain capacity to enable catheter delivery. Methods. Four thermoset acrylic copolymers containing benzyl methacrylate (BzMA) and bisphenol A ethoxylate diacrylate (Mn∼512, BPA) were designed with differing thermomechanical properties. Finite element analysis (FEA) was performed to ensure that the materials were able to undergo the strains imposed by crimping, and fabricated devices were subjected to force-monitored crimping, constrained recovery, and bench-top thrombectomy. Results. Devices with 25 and 35 mole% BPA exhibited the highest recovery stress and the highest brittle response as they broke upon constrained recovery. On the contrary, the 15 mole% BPA devices endured all testing and their recovery stress (5 kPa) enabled successful bench-top thrombectomy in 2/3 times, compared to 0/3 for the devices with the lowest BPA content. Conclusion. While the 15 mole% BPA devices provided the best trade-off between device integrity and performance, other SMP systems that offer recovery stresses above 5 kPa without increasing brittleness to the point of causing device failure would be more suitable for this application.

scholarly journals Spontaneous Intracerebral Haematoma-II:Post-Operative Changes and Outcome of Burrhole Aspiration after Urokinase Mediated Clot Lysis

2017 ◽  
Vol 34 (2) ◽  
pp. 64-75
Author(s):  
Mohammad Nazrul Hossain ◽  
Shahryar Nabi ◽  
Sk Sader Hossain
Keyword(s):  
Diabetes Mellitus ◽  
Blood Clot ◽  
Clot Lysis ◽  
Intracerebral Hematoma ◽  
Invasive Technique ◽  
Intracerebral Haematoma ◽  
College Hospital ◽  
Clot Removal ◽  
Haematoma Volume ◽  
Number Of Patients

Background: Treatments of intracerebral hematoma (ICH) are controversial and surgical interventions in spontaneous ICH are required and more accepted. Although advantage of neurosurgical intervention conservative treatment of ICH has not been established, recent reports have suggested favourable effects of blood clot removal after liquefaction by means of urokinase.Objectives: To study the intervention by and out come in without or with complications of Burrhole aspiration treatment after urokinase mediated clot lysis; Study Design : Prospective interventional study. Place and Duration of Study: Departments of Neurosurgery and Radiology & Imaging ,Dhaka Medical College Hospital, Dhaka, Bangladesh from July 2010 to December 2010;Materials &Methods: A total of 30 Bangladeshi patients with spontaneous ICH (Age range: 40-75yrs,Mean age ±SD:59.1±11.52 years, Gender : 22 males, 8 females) full filling the criteria for spontaneous ICH were included in the study. The desired information relevant to the objectives were obtained and recorded carefully using a structured questionnaire; The Patients were treated with Burrhole aspiration after urokinase mediated lysis , evaluated for out come , complications and death and statistically analyzed ;Results: The results on delays of intervention ,types of intervention, doses of urokinase, post-operative changes in haematoma volume, outcome with Glasgow outcome scale(GOS) and GOS at follow–up, complications and death were presented with statistical analyses and significance .The outcome and death were compared with various variables such as hypertension (p <0.05), diabetes mellitus (p< 0.05) primary GOS (P<0.05),site of hematoma (p<0.05),volume of haematoma (p<0.05),ventricular extension of hematoma (p<0.05) and delay from ictus to intervention (p<0.05).Conclusion : It was observed that early treatment (within 24 hours of occurance) by using minimally invasive technique and clot removal by urokinase mediated lysis can improve the consequences especially those with haematoma volume < 40 ml, lobar haematoma and without ventricular extension. Bad prognostic factors were increase of blood pressure, diabetes mellitus, GOS level <8, haematoma in the basal ganglia , ventricular extension of the haematoma volume> 40 ml and delay in intervention. However, the present was conducted with 30 patients only and therefore, studies with larger number of patients are required to draw more meticulous and more definitive conclusions.J Bangladesh Coll Phys Surg 2016; 34(2): 64-75

In Vitro Design Investigation of a Rotating Helical Magnetic Swimmer for Combined 3-D Navigation and Blood Clot Removal

2020 ◽  
Vol 36 (3) ◽  
pp. 975-982
Author(s):  
Julien Leclerc ◽  
Haoran Zhao ◽  
Daniel Bao ◽  
Aaron T. Becker
Keyword(s):  
Blood Clot ◽  
Clot Removal

scholarly journals THE EFFICACY OF NASOGASTRIC TUBE IN A LARGE BLOOD CLOT EVACUATION DURING CYSTOSCOPY

2016 ◽  
Vol 23 (2) ◽  
Author(s):  
Caesar Khairul Wallad ◽  
Jumadi Santoso ◽  
Kuncoro Adi
Keyword(s):  
Nasogastric Tube ◽  
Negative Pressure ◽  
Blood Clot ◽  
Clot Removal ◽  
Blood Clots ◽  
Tube Suction ◽  
Clot Evacuation

Objective: In this study we introduce using nasogatric tube as an alternative to procure a safe and efficient way to remove large troublesome blood clots during cystoscopy procedure. Material & methods: We prospectively perform blood clot evacuation using nasogastric tube suction (NGT) on 21 patients in Hasan Sadikin GeneralHospital Bandung,within 6 months period. A 24 fr sheath and 16 fr NGT connected to suction unit with a 300 mmhg negative pressure was set. A repetitive back and forth technique was set in motion during the procedure. Cystoscopy time and NGT suction time was documented. Results: All patients were successfully managed with this method without complication during the procedure. The average time for clot removal was 5 minutes 8 seconds with average cystoscopy time was 20 minutes 12 seconds and average estimated blood clots volume was 483 grams. Conclusion: Evacuation using NGT suction is effective, safe and an efficient way to remove a large bothersome clots.

scholarly journals Blood clot removal by cryoextraction in critically ill patients with pulmonary hemorrhage

2019 ◽  
Vol 11 (10) ◽  
pp. 4319-4327 ◽  
Author(s):  
Lars Henning Schmidt ◽  
Arik Bernard Schulze ◽  
Dennis Goerlich ◽  
Christoph Schliemann ◽  
Torsten Kessler ◽  
...  
Keyword(s):  
Critically Ill ◽  
Critically Ill Patients ◽  
Blood Clot ◽  
Pulmonary Hemorrhage ◽  
Clot Removal

Subarachnoid hemorrhage as a cause of an adaptive response in cerebral arteries

2000 ◽  
Vol 93 (3) ◽  
pp. 463-470 ◽  
Author(s):  
Marcus Stoodley ◽  
R. Loch Macdonald ◽  
Bryce Weir ◽  
Linda S. Marton ◽  
Lydia Johns ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Adaptive Response ◽  
Contractile Activity ◽  
Blood Clot ◽  
Cerebral Arteries ◽  
Content Type ◽  
Clot Removal ◽  
Basilar Arteries ◽  
Subarachnoid Blood ◽  
Fine Print

Object. It is not known whether the factors responsible for vasospasm after subarachnoid hemorrhage (SAH) cause the cerebral arteries to be narrowed independent of the subarachnoid blood clot or whether the continued presence of clot is required for the entire time of vasospasm. The authors undertook the present study to investigate this issue.Methods. To distinguish between these possibilities, bilateral SAH was induced in monkeys. The diameters of the monkeys' cerebral arteries were measured on angiograms obtained on Days 0 (the day of SAH), 1, 3, 5, 7, and 9. The subarachnoid blood clot was removed surgically on Day 1, 3, or 5 or, in control animals, was not removed until the animals were killed on Day 7 or 9. The concentrations of hemoglobins and adenosine triphosphate (ATP), substances believed to cause vasospasm, were measured in the removed clots and the contractile activity of the clots was measured in monkey basilar arteries in vitro. If the clot was removed 1 or 3 days after placement, vasospasm was significantly diminished 4 days after clot removal. Clot removal on Day 5 had no marked effect on vasospasm. There was a significant decrease over time in hemoglobin and ATP concentrations and in the contractile activity of the clots, although substantial hemoglobin and contractile activity was still present on Day 7.Conclusions. The authors infer from these results that vasospasm requires the presence of subarachnoid blood for at least 3 days, whereas by Day 5 vasospasm is less dependent on subarachnoid blood clot. Because the clot still contains substantial amounts of hemoglobin and contractile activity after 5 days, there may be an adaptive response in the cerebral arteries that allows them to relax in the presence of the stimulus that earlier caused contraction.

The effect of timing of clot removal on chronic vasospasm in a primate model

1987 ◽  
Vol 67 (4) ◽  
pp. 558-564 ◽  
Author(s):  
Yuji Handa ◽  
Bryce K. A. Weir ◽  
Michael Nosko ◽  
Russ Mosewich ◽  
Tsutomu Tsuji ◽  
...  
Keyword(s):  
Cerebral Vasospasm ◽  
Subarachnoid Space ◽  
Blood Clot ◽  
Autologous Blood ◽  
Cerebral Arteries ◽  
Neurological Deficits ◽  
Physiological Status ◽  
Cerebral Vessel ◽  
Clot Removal ◽  
Chronic Cerebral Vasospasm

✓ The effect of complete clot removal at times from 48 to 96 hours after subarachnoid hemorrhage (SAH) on the development of chronic cerebral vasospasm was evaluated to determine whether there is a critical point after which clot removal is ineffective in preventing vasospasm. Thirty cynomolgus monkeys were randomized to one of five groups: sham-operated group, clot removal at 48 hours after SAH (48-hour group), clot removal at 72 hours after SAH (72-hour group), clot removal at 96 hours after SAH (96-hour group), and clot placement only (clot group). Standard microsurgical techniques were used to dissect bilaterally the major cerebral arteries free of arachnoid. An autologous blood clot averaging 4.2 gm was placed around the vessels in the subarachnoid space of the monkeys in the 48-hour, 72-hour, 96-hour, and clot groups. Physiological saline was instilled into the subarachnoid space of the sham-operated animals. Animals in the clot-removal groups underwent surgical clot removal at the determined times for each group. Two animals in each of the sham-operated and clot groups were subjected to reoperation at each of 48, 72, and 96 hours after SAH. The incisions were reopened and then simply reclosed. Neurological status, angiographic cerebral vessel caliber, and physiological status were evaluated before and 7 days after SAH induction. There were no significant neurological deficits in the sham-operated, 48-hour, or 72-hour groups. Two animals in each of the 96-hour and clot groups showed deterioration in level of consciousness developing on Day 4 or 5 after SAH induction. All the major cerebral arteries of the animals in the clot and 96-hour groups showed significant vasospasm (p < 0.01) on Day 7. Animals in the 72-hour group had significant vasospasm (p < 0.05) of the internal carotid and middle cerebral arteries but not the anterior cerebral arteries. There was no significant vasospasm (p > 0.05) in any of the cerebral arteries in the 48-hour group. Severity of vasospasm paralleled the duration of contact between the blood clot and the cerebral vessels. Evacuation of the subarachnoid hematoma later than 48 hours after SAH resulted in no significant reduction in the degree of chronic cerebral vasospasm. It is suggested that clot removal at early operation is likely to be useful only if it is performed within 48 hours of SAH.

Sign in / Sign up

Export Citation Format

Share Document