| 1. |
- Böhler, Christian, et al.
(författare)
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Multilayer Arrays for Neurotechnology Applications (MANTA): Chronically Stable Thin-Film Intracortical Implants
- 2023
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Ingår i: Advanced Science. - : John Wiley & Sons. - 2198-3844. ; 10:14
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Tidskriftsartikel (refereegranskat)abstract
- Flexible implantable neurointerfaces show great promise in addressing one of the major challenges of implantable neurotechnology, namely the loss of signal connected to unfavorable probe tissue interaction. The authors here show how multilayer polyimide probes allow high-density intracortical recordings to be combined with a reliable long-term stable tissue interface, thereby progressing toward chronic stability of implantable neurotechnology. The probes could record 10–60 single units over 5 months with a consistent peak-to-peak voltage at dimensions that ensure robust handling and insulation longevity. Probes that remain in intimate contact with the signaling tissue over months to years are a game changer for neuroscience and, importantly, open up for broader clinical translation of systems relying on neurotechnology to interface the human brain.
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| 2. |
- Boyraz Baykas, Pinar, 1981, et al.
(författare)
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Design of a Low-cost Tactile Robotic Sleeve for Autonomous Endoscopes and Catheters
- 2020
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Ingår i: Measurement and Control. - : SAGE Publications. - 0020-2940. ; 53:3-4, s. 613-626
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Tidskriftsartikel (refereegranskat)abstract
- Recent developments in medical robotics have been significant, supporting the minimally invasive operation requirements, such as smaller devices and more feedback available to surgeons. Nevertheless, the tactile feedback from a catheter or endoscopic type robotic device has been restricted mostly on the tip of the device and was not aimed to support the autonomous movement of the medical device during operation. In this work, we design a robotic sheath/sleeve with a novel and more comprehensive approach, which can function for whole-body or segment-based feedback control as well as diagnostic purposes. The robotic sleeve has several types of piezo-resistive pressure and extension sensors, which are embedded at several latitudes and depths of the silicone substrate. The sleeve takes the human skin as a biological model for its structure. It has a better tactile sensation of the inner tissues in the torturous narrow channels such as cardiovascular or endo-luminal tracts in human body thus can be used to diagnose abnormalities. In addition to this capability, using the stretch sensors distributed alongside its body, the robotic sheath/sleeve can perceive the ego-motion of the robotic backbone of the catheter and can act as a position feedback device. Because of the silicone substrate, the sleeve contributes toward safety of the medical device passively by providing a compliant interface. As an active safety measure, the robotic sheath can sense blood-clots or sudden turns inside a channel and by modifying the local trajectory, and can prevent embolisms or tissue rupture. In the future, advanced manufacturing techniques will increase the capabilities of the tactile robotic sleeve.
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| 3. |
- Zanoli, Massimiliano, 1989
(författare)
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Ultra wideband microwave hyperthermia for brain cancer treatment
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Despite numerous clinical trials demonstrating that microwave hyperthermia is a powerful adjuvant modality in the treatment of cancers, there have been few instances where this method has been applied to brain tumors. The reason is a combination of anatomical and physiological factors in this site that require an extra degree of accuracy and precision in the thermal dose delivery. Current clinical applicators are not able to provide such control, partly because they are designed to operate at a single fixed frequency. In terms of treatment planning, the use of a single frequency is limiting as the size of the focal spot cannot be modified to accommodate the specific tumor volume and location. The introduction of ultra wide-band (UWB) systems opens up an opportunity to overcome these limitations, as they convey the possibility of adapting the focal spot and obtaining different power deposition patterns to reduce the heating of healthy tissues. In this thesis, we explore whether the current SAR-based treatment planning methods can be meaningfully translated to the UWB setting and propose new solutions for deep UWB microwave hyperthermia. We analyze the most commonly used cost functions for treatment planning optimization and discuss their suitability for use with UWB systems. Then, we propose a novel SAR-based cost function (HCQ) for UWB optimization that exhibits a high correlation with the resulting tumor temperature. To solve for the HCQ, we describe a novel, time-reversal-based, iterative scheme for a rapid and efficient optimization of UWB treatment plans. Next, we investigate the design possibilities of UWB brain applicators and introduce a fast E-field approximation scheme to quickly explore a large number of array configurations. The method determines the best antenna arrangement around the head with respect to the multiple objectives and requirements of clinical hyperthermia. Together, the proposed solutions manage to achieve the level of tumor coverage and hot-spot suppression that is necessary for a successful treatment. Finally, we investigate the benefit of integrating hyperthermia delivered by an optimized UWB applicator into the radiation therapy plan for a pediatric medulloblastoma patient. The results suggest that UWB microwave hyperthermia for brain cancer treatment is feasible and motivate efforts for further development of UWB applicators and systems.
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| 4. |
- Mishra, A., et al.
(författare)
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Progress in paper-based analytical devices for climate neutral biosensing
- 2022
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Ingår i: Biosensors and Bioelectronics: X. - : Elsevier BV. - 2590-1370. ; 11, s. 100166-
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Tidskriftsartikel (refereegranskat)abstract
- Disposable diagnostics is ramping up the development of green practices for healthcare. Paper is an excellent natural substrate for emerging low-cost, ecologically acceptable analytical devices. Flexibility, three-dimensional fibre structure, mechanical characteristics, ease of manufacturing and customization are the key advantages of cellulose as preferable materials for green analytical devices. This article overviews the advances in paper-based optical and electroanalytical devices, including manufacturing, validation of functions, detection methodology, and applications. The renewable resources hold the potential to accomplish the biodegradable analytical techniques due to their climate neutral waste management. The paper-based electrodes have demonstrated excellent performance for diagnostics while being eco-friendly at the same time. Therefore, the forthcoming sustainable diagnostics approaches require integrating paper-based analytical devices (PADs) built out of disposable electrodes. The diverse green materials and methods facilitate climate neural point-of-care products for the net-zero market. Numerous researches have been conducted in recent years to develop innovative technologies capable of analysing clinical samples quickly, accurately, simply, and sensitively, with the primary objective of offering competent tools for illness diagnosis and treatment efficacy follow-up. The micro-PADs show excellent abilities for quick onsite diagnostics within μ-level detection range. The sensitivity, stability, and reliability of analytical devices are the essential factors enabling larger-scale production and commercialization. The projected fabrication and analytical methods in the direction of paper-based devices could be nicely and reliably utilized for understanding and adaptation of climate neutral diagnostic technologies in healthcare sector. This detailed article discusses the sustainable framework that integrates green bioelectronics and sensor technologies adhering to diverse functionality for health and the environment. The paper-based digital technology (PDigiT) could be employed as a simple, cost-effective, and efficient net-zero technology for real-time monitoring of outbreaks and bio-surveillance.
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| 5. |
- Pigot, Harry, et al.
(författare)
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Ex Vivo Working Porcine Heart Model
- 2024. - 2
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Ingår i: Experimental Models of Cardiovascular Diseases : Methods and Protocols - Methods and Protocols. - 1064-3745 .- 1940-6029. - 9781071638460 - 9781071638484 - 9781071638453 ; 2803, s. 87-107
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Ex vivo working porcine heart models allow for the study of a heart’s function and physiology outside the living organism. These models are particularly useful due to the anatomical and physiological similarities between porcine and human hearts, providing an experimental platform to investigate cardiac disease or assess donor heart viability for transplantation. This chapter presents an in-depth discussion of the model’s components, including the perfusate, preload, and afterload. We explore the challenges of emulating cardiac afterload and present a historical perspective on afterload modeling, discussing various methodologies and their respective limitations. An actively controlled afterload device is introduced to enhance the model’s ability to rapidly adjust pressure in the large arteries, thereby providing a more accurate and dynamic experimental model. Finally, we provide a comprehensive experimental protocol for the ex vivo working porcine heart model.
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| 6. |
- Lindau, Björn, 1961, et al.
(författare)
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Virtual fixturing: Inspection of a non-rigid detail resting on 3-points to estimate free state and over-constrained shapes
- 2020
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Ingår i: ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE). ; 2B-2020
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Konferensbidrag (refereegranskat)abstract
- When the geometry of a non-rigid part or pre-assembly is measured fully clamped (over-constrained) in a measurement fixture, the spring-back information and influence from gravity forces are usually lost in the collected data. From the 3D-measurement data, it is hard to understand built in tensions, and the detail's tendency to bend, twist and warp after release from the measurement fixture. These effects are however important to consider when analyzing each part´s contribution to geometrical deviations after assembly. In this paper a method is presented, describing how free state shape and over-constrained shape of a measured detail can be virtually estimated starting from acquired data when the part or the preassembly is resting on only 3-points. The objective is to minimize the information loss, to spare measurement resources and to allow for a wider use of the collected data, describing the geometry. Part stiffnesses, part to part contacts and gravity effects are considered in the proposed method. The method is based on 3D-scanning techniques to acquire the shape of the measured object. Necessary compensations for part stiffnesses and gravity effects are based upon Finite Element Analysis (FEA) and the Method of Influence Coefficients (MIC). The presented method is applied to an industrial case to demonstrate its potential. The results show that estimated over-constrained shapes show good resemblance with measurements acquired when part is over-constrained in its measurement fixture.
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| 7. |
- Korn, Leonie, et al.
(författare)
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Dual-Modality Volume Measurement Integrated on a Ventricular Assist Device
- 2022
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Ingår i: IEEE Transactions on Biomedical Engineering. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9294 .- 1558-2531. ; 69:3, s. 1151-1161
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Ventricular assist devices (VADs)are implanted in patients suffering from end-stage heartfailure to sustain the blood circulation. Real-time volumemeasurement could be a valuable tool to monitor patientsand enable physiological control strategies to provide in-dividualized therapy. However, volume measurement usingone sensor modality requires re-calibration in the criticaltime post VAD implantation. Methods: To overcome thislimitation, we have integrated ultrasound and impedancevolume measurement techniques into a cannula of an api-cal VAD. We tested both modalities across a volume rangefrom 140–420 mL using two differently sized and shapedbiventricular silicon heart phantoms, which were subjectedto physiological pressures in an in-vitro test bench. Wecompared results from standard calibrated measurementswith calculations found by a quadratic optimization for thesingle modality and their combination (dual-modality) andvalidated the results using twofold cross-validation. Re-sults: The dual-modality approach resulted in most favor-able limits of agreement (LOA) of −0.83 ± 1.54% comparedto −13.88 ± 5.90% for ultrasound and −43.45 ± 10.28% forelectric impedance, separately. Conclusion: The results ofthe dual-modality approach were as accurate as the stan-dard calibrated measurement and valid over a large rangeof volumes (140–420 mL). In this in-vitro study, we showhow a dual-modality ventricular volume measurement of ul-trasound and electric impedance increases the robustnessand renders calibration obsolete. Significance: Ventricularvolumes could be measured accurately in the critical periodpost VAD implantation despite ventricular remodeling.
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| 8. |
- Marques, Filipe, et al.
(författare)
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New through-the-needle brush for pancreatic cysts assessment : a randomized control trial
- 2023
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Ingår i: iGIE. - : Elsevier BV. - 2949-7086.
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Tidskriftsartikel (refereegranskat)abstract
- AbstractObjectiveCurrent endoscopic ultrasound technologies (EUS) are suboptimal in the assessment of pancreatic cystic lesions (PCLs). We developed a new through-the- needle brush, the "loop brush", to improve the cellular yield, and thereby sensitivity,of EUS fine needle aspiration (EUS-FNA) of pancreatic cysts. In this study, we aim to evaluate its safety and efficacy.DesignWe performed an in-vivo randomized controlled trial in pigs using artificial cysts. In one group, the loop brush was deployed through a 22G EUS-FNA needle into the cysts. In the control group, cystic punction was performed with standard EUS- FNA. Loop brushes were visually inspected post-procedure. Cytological assessment, cell counting, and hemoglobin analysis were performed in samples from both groups.ResultsArtificial cysts (n=114) were punctured in six pigs, 57 in each group. Neither adverse events nor significant device malfunction occurred during loop brushing. Samples collected with the brush had non-detectable concentrations of hemoglobin in 72% (41/57) of cases, and 26% (16/57) had less than 0.6 g/dL, with no significant difference to the controls (p=0.32). Brushing cell counts were associated with significantly increased cell counts (11.7× median difference, p<.0001). Cytological smears were diagnostic in 77% of cases in the brushing group, while 54% in the control group (p=0.01, Fisher’s exact test; p=0.006, Chi-square test).ConclusionsThe new loop brush procedure appears to be safe, causing neither significant bleeding nor device malfunction. Samples obtained with the loop brush were suitable for cytological analysis and showed significantly higher cell yield than controls. Further clinical studies are warranted.
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| 9. |
- Zeng, Xuezhi, 1980, et al.
(författare)
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Investigation of an ultra wideband noise sensor for health monitoring
- 2020
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 20:4
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Tidskriftsartikel (refereegranskat)abstract
- Quick on-scene assessment and early intervention is the key to reduce the mortality of stroke and trauma patients, and it is highly desirable to develop ambulance-based diagnostic and monitoring devices in order to provide additional support to the medical personnel. We developed a compact and low cost ultra wideband noise sensor for medical diagnostics and vital sign monitoring in pre-hospital settings. In this work, we demonstrated the functionality of the sensor for respiration and heartbeat monitoring. In the test, metronome was used to manipulate the breathing pattern and the heartbeat rate reference was obtained with a commercial electrocardiogram (ECG) device. With seventeen tests performed for respiration rate detection, sixteen of them were successfully detected. The results also show that it is possible to detect the heartbeat rate accurately with the developed sensor.
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| 10. |
- Marques, Filipe, et al.
(författare)
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Absorbable cyst brushes
- 2023
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Ingår i: Biomedical microdevices (Print). - : Springer Nature. - 1387-2176 .- 1572-8781. ; 25:3
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Tidskriftsartikel (refereegranskat)abstract
- Cytobrushes are used for low-invasive sample collection and screening in multiple diseases, with a significant impact on early detection, prevention, and diagnosis. This study focuses on improving the safety of cell brushing in hard-to-reach locations by exploring brush construction from absorbable materials. We investigated the efficacy of loop brushes made of absorbable suture wires of Chirlac, Chirasorb, Monocryl, PDS II, Vicryl Rapid, Glycolon, and Catgut during their operation in conjunction with fine-needle aspiration in an artificial cyst model. PDS II brushes demonstrated the highest efficiency, while Monocryl and Catgut also provided a significant brushing effect. Efficient brushes portrayed higher flexural rigidity than their counterparts, and their efficiency was inversely proportional to their plastic deformation by the needle. Our results open avenues for safer cell biopsies in hard-to-reach locations by utilizing brushes composed of absorbable materials.
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