Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 57
Filter
1.
J Econ Entomol ; 116(5): 1943-1947, 2023 Oct 10.
Article in English | MEDLINE | ID: mdl-37669010

ABSTRACT

Lycorma delicatula White (spotted lanternfly; SLF) is an invasive pest insect threatening increased agricultural costs as it spreads rapidly westward across the United States. As such, surveying was conducted adjacent to the insect's westernmost quarantine area in 2021-2022 to support multi-state monitoring. Specifically, 2,077 visual and sticky-trap surveys were performed in 13 repeatedly surveyed plots strategically located near high-traffic roadways and rail-lines along the Ohio-West Virginia border. Sites were located in Jefferson (Ohio), Brooke (West Virginia), and Hancock (West Virginia) counties. Only one SLF was detected in 2021 (the third documented Ohio site containing SLF) in close proximity to a railway, consistent with rail-mediated dispersal trends recorded throughout the United States. Thirty-one SLF were captured in 2 Ohio sites in 2022, 30 of which were captured at the same railway site as in 2021. However, 1 of the 31 SLF was found in a plot on a university campus 1.25 km from the nearest railway, along with 10 additional specimens found in a follow-up visual survey of a neighboring woodlot. Failure to detect SLF at nearby survey plots nearer to the closest rail line and commuter parking lots suggests local unaided dispersal in a state with primarily train-mediated dispersal-mirroring trends in affected states with more established SLF populations. Data from this survey are valuable for establishing baselines and early-invasion patterns of SLF dispersal into Ohio, anticipating SLF expansion patterns in Ohio, and eventually contributing to improved SLF dispersal modeling in Ohio, the Midwest, and the United States.

2.
Article in English | MEDLINE | ID: mdl-35925858

ABSTRACT

The force-generating capacity of skeletal muscle is an important metric in the evaluation and diagnosis of musculoskeletal health. Measuring changes in muscle force exertion is essential for tracking the progress of athletes during training, for evaluating patients' recovery after muscle injury, and also for assisting the diagnosis of conditions such as muscular dystrophy, multiple sclerosis, or Parkinson's disease. Traditional hardware for strength evaluation requires technical training for operation, generates discrete time points for muscle assessment, and is implemented in controlled settings. The ability to continuously monitor muscle force without restricting the range of motion or adapting the exercise protocol to suit specific hardware would allow for a richer dataset that can help unlock critical features of muscle health and strength evaluation. In this paper, we employ wearable, ultra-sensitive soft strain sensors for tracking changes in muscle deformation during contractions. We demonstrate the sensors' sensitivity to isometric contractions, as well as the sensors' capacity to track changes in peak torque over the course of an isokinetic fatiguing protocol for the knee extensors. The wearable soft system was able to efficiently estimate peak joint torque reduction caused by muscle fatigue (mean NRMSE = 0.15±0.03 ).


Subject(s)
Isometric Contraction , Wearable Electronic Devices , Humans , Isometric Contraction/physiology , Knee Joint/physiology , Muscle Fatigue/physiology , Muscle Strength/physiology , Muscle, Skeletal/physiology , Torque
3.
Cardiovasc Eng Technol ; 13(1): 120-128, 2022 02.
Article in English | MEDLINE | ID: mdl-34263419

ABSTRACT

PURPOSE: In clinical practice, many patients with right heart failure (RHF) have elevated pulmonary artery pressures and increased afterload on the right ventricle (RV). In this study, we evaluated the feasibility of RV augmentation using a soft robotic right ventricular assist device (SRVAD), in cases of increased RV afterload. METHODS: In nine Yorkshire swine of 65-80 kg, a pulmonary artery band was placed to cause RHF and maintained in place to simulate an ongoing elevated afterload on the RV. The SRVAD was actuated in synchrony with the ventricle to augment native RV output for up to one hour. Hemodynamic parameters during SRVAD actuation were compared to baseline and RHF levels. RESULTS: Median RV cardiac index (CI) was 1.43 (IQR, 1.37-1.80) L/min/m2 and 1.26 (IQR 1.05-1.57) L/min/m2 at first and second baseline. Upon PA banding RV CI fell to a median of 0.79 (IQR 0.63-1.04) L/min/m2. Device actuation improved RV CI to a median of 0.87 (IQR 0.78-1.01), 0.85 (IQR 0.64-1.59) and 1.11 (IQR 0.67-1.48) L/min/m2 at 5 min (p = 0.114), 30 min (p = 0.013) and 60 (p = 0.033) minutes respectively. Statistical GEE analysis showed that lower grade of tricuspid regurgitation at time of RHF (p = 0.046), a lower diastolic pressure at RHF (p = 0.019) and lower mean arterial pressure at RHF (p = 0.024) were significantly associated with higher SRVAD effectiveness. CONCLUSIONS: Short-term augmentation of RV function using SRVAD is feasible even in cases of elevated RV afterload. Moderate or severe tricuspid regurgitation were associated with reduced device effectiveness.


Subject(s)
Heart Failure , Robotics , Tricuspid Valve Insufficiency , Animals , Heart Failure/therapy , Heart Ventricles/surgery , Humans , Pulmonary Artery/surgery , Swine , Tricuspid Valve/diagnostic imaging , Tricuspid Valve/surgery , Tricuspid Valve Insufficiency/diagnostic imaging , Tricuspid Valve Insufficiency/surgery
4.
Sci Transl Med ; 13(614): eabe8868, 2021 Oct 06.
Article in English | MEDLINE | ID: mdl-34613813

ABSTRACT

Mechanical stimulation (mechanotherapy) can promote skeletal muscle repair, but a lack of reproducible protocols and mechanistic understanding of the relation between mechanical cues and tissue regeneration limit progress in this field. To address these gaps, we developed a robotic device equipped with real-time force control and compatible with ultrasound imaging for tissue strain analysis. We investigated the hypothesis that specific mechanical loading improves tissue repair by modulating inflammatory responses that regulate skeletal muscle regeneration. We report that cyclic compressive loading within a specific range of forces substantially improves functional recovery of severely injured muscle in mice. This improvement is attributable in part to rapid clearance of neutrophil populations and neutrophil-mediated factors, which otherwise may impede myogenesis. Insights from this work will help advance therapeutic strategies for tissue regeneration broadly.


Subject(s)
Robotic Surgical Procedures , Robotics , Muscle, Skeletal , Neutrophils , Regeneration
5.
Antibiotics (Basel) ; 10(10)2021 Oct 06.
Article in English | MEDLINE | ID: mdl-34680794

ABSTRACT

Antibiotics play a vital role in aquaculture where they are commonly used to treat bacterial diseases. However, the impact of antibiotic treatment on the gut microbiome and the development of antimicrobial resistance in Nile tilapia (Oreochromis niloticus) over time remains to be fully understood. In this study, fish were fed a single treatment of oxytetracycline (100 mg/kg/day) for eight days, followed by a 14-day withdrawal period. Changes in the distal gut microbiome were measured using 16S rRNA sequencing. In addition, the abundance of antimicrobial resistance genes was quantified using real-time qPCR methods. Overall, the gut microbiome community diversity and structure of Nile tilapia was resilient to oxytetracycline treatment. However, antibiotic treatment was associated with an enrichment in Plesiomonas, accompanied by a decline in other bacteria taxa. Oxytetracycline treatment increased the proportion of tetA in the distal gut of fish and tank biofilms of the treated group. Furthermore, the abundance of tetA along with other tetracycline resistance genes was strongly correlated with a number of microbiome members, including Plesiomonas. The findings from this study demonstrate that antibiotic treatment can exert selective pressures on the gut microbiome of fish in favour of resistant populations, which may have long-term impacts on fish health.

6.
JACC Basic Transl Sci ; 5(3): 229-242, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32215347

ABSTRACT

Left ventricular failure is strongly associated with secondary mitral valve regurgitation. Implantable soft robotic devices are an emerging technology that enables augmentation of a native function of a target tissue. We demonstrate the ability of a novel soft robotic ventricular assist device to dynamically augment left ventricular contraction, provide native pulsatile flow, simultaneously reshape the mitral valve apparatus, and eliminate the associated regurgitation in an Short-term large animal model of acute left ventricular systolic dysfunction.

7.
Sci Transl Med ; 12(531)2020 02 19.
Article in English | MEDLINE | ID: mdl-32075944

ABSTRACT

Congenital heart valve disease has life-threatening consequences that warrant early valve replacement; however, the development of a growth-accommodating prosthetic valve has remained elusive. Thousands of children continue to face multiple high-risk open-heart operations to replace valves that they have outgrown. Here, we demonstrate a biomimetic prosthetic valve that is geometrically adaptable to accommodate somatic growth and structural asymmetries within the heart. Inspired by the human venous valve, whose geometry is optimized to preserve functionality across a wide range of constantly varying volume loads and diameters, our balloon-expandable synthetic bileaflet valve analog exhibits similar adaptability to dimensional and shape changes. Benchtop and acute in vivo experiments validated design functionality, and in vivo survival studies in growing sheep demonstrated that mechanical valve expansion accommodated growth. As illustrated in this work, dynamic size adaptability with preservation of unidirectional flow in prosthetic valves thus offers a paradigm shift in the treatment of heart valve disease.


Subject(s)
Cardiac Surgical Procedures , Heart Valve Prosthesis , Heart Valves , Prosthesis Design
8.
J Biomed Opt ; 24(6): 1-15, 2019 06.
Article in English | MEDLINE | ID: mdl-31222989

ABSTRACT

We report a compact rigid instrument capable of delivering en-face optical coherence tomography (OCT) images alongside (epi)-fluorescence endomicroscopy (FEM) images by means of a robotic scanning device. Two working imaging channels are included: one for a one-dimensional scanning, forward-viewing OCT probe and another for a fiber bundle used for the FEM system. The robotic scanning system provides the second axis of scanning for the OCT channel while allowing the field of view (FoV) of the FEM channel to be increased by mosaicking. The OCT channel has resolutions of 25 / 60 µm (axial/lateral) and can provide en-face images with an FoV of 1.6 × 2.7 mm2. The FEM channel has a lateral resolution of better than 8 µm and can generate an FoV of 0.53 × 3.25 mm2 through mosaicking. The reproducibility of the scanning was determined using phantoms to be better than the lateral resolution of the OCT channel. Combined OCT and FEM imaging were validated with ex-vivo ovine and porcine tissues, with the instrument mounted on an arm to ensure constant contact of the probe with the tissue. The OCT imaging system alone was validated for in-vivo human dermal imaging with the handheld instrument. In both cases, the instrument was capable of resolving fine features such as the sweat glands in human dermal tissue and the alveoli in porcine lung tissue.


Subject(s)
Dermis/diagnostic imaging , Diagnostic Imaging/methods , Microscopy, Fluorescence/methods , Robotic Surgical Procedures/methods , Tomography, Optical Coherence/methods , Animals , Humans , Pulmonary Alveoli/diagnostic imaging , Reproducibility of Results , Sweat Glands/diagnostic imaging , Swine
9.
Surg Endosc ; 33(8): 2710-2718, 2019 08.
Article in English | MEDLINE | ID: mdl-31227900

ABSTRACT

BACKGROUND: Ligation clips are used ubiquitously throughout minimally invasive surgery for apposition of tissues. Their size limits their application beyond ligation of small tubular structures. A novel clip and clip applicator that allows for broad-area clamping and rotation has been developed by our team. The primary aim of this study is to provide preliminary data assessing tensile strength of the clip across apposed segments of bowel. METHODS: A comparative study evaluating the maximum load (N) held across two apposed tissues by (a) our novel broad-area clip and (b) a conventional commercial clip was performed. Two sections of porcine bowel were clamped together and the maximum load (N) was measured using a tensile strength material testing machine. A preliminary experiment comparing staple line leak pressures in a porcine model ± clip enforcement of staple line was also conducted. p < 0.05 determined statistical significance. RESULTS: Twenty-four samples (intervention = 15; control = 9) of porcine bowel annealed by surgical clips were tested. The mean maximum force withheld by the bowel and staples was greater for our novel clip design (2.043 ± 0.831 N) than the control clip (1.080 ± 0.466 N, p = 0.004). Ten staple line (intervention = 5; control = 5) pressures of porcine bowel were measured. There was no statistically significant difference between the leak pressures with clip reinforcement (84.8 mmHg; range 71.8-109.8 mmHg), or without (54.1 mmHg; range 26.3-98.9 mmHg). CONCLUSION: These preliminary results suggest that our novel clip is able to withstand higher tensile force across tissues compared to a leading commercial clip. A small preliminary trial of effect on leak pressures demonstrated no statistical significance; however, increasing reliability of staple line deformation may be a clinically important finding. Whilst further iteration of product design and clinical testing is required, this product may occupy an important clinical niche through staple line reinforcement, enterotomy closure and other applications.


Subject(s)
Intestines/surgery , Ligation/instrumentation , Minimally Invasive Surgical Procedures/instrumentation , Surgical Stapling/instrumentation , Anastomosis, Surgical , Animals , Equipment Design , Intestines/physiology , Models, Animal , Pressure , Reproducibility of Results , Surgical Instruments , Surgical Stapling/methods , Swine , Tensile Strength
10.
IEEE Trans Biomed Eng ; 66(1): 208-216, 2019 01.
Article in English | MEDLINE | ID: mdl-29993497

ABSTRACT

OBJECTIVE: Probe-based confocal endomicroscopy is an emerging high-magnification optical imaging technique that provides in vivo and in situ cellular-level imaging for real-time assessment of tissue pathology. Endomicroscopy could potentially be used for intraoperative surgical guidance, but it is challenging to assess a surgical site using individual microscopic images due to the limited field-of-view and difficulties associated with manually manipulating the probe. METHODS: In this paper, a novel robotic device for large-area endomicroscopy imaging is proposed, demonstrating a rapid, but highly accurate, scanning mechanism with image-based motion control, which is able to generate histology-like endomicroscopy mosaics. The device also includes, for the first time in robotic-assisted endomicroscopy, the capability to ablate tissue without the need for an additional tool. RESULTS: The device achieves preprogrammed trajectories with positioning accuracy of less than 30 [Formula: see text], while the image-based approach demonstrated that it can suppress random motion disturbances up to [Formula: see text]. Mosaics are presented from a range of ex vivo human and animal tissues, over areas of more than [Formula: see text], scanned in approximate [Formula: see text]. CONCLUSION: This paper demonstrates the potential of the proposed instrument to generate large-area, high-resolution microscopic images for intraoperative tissue identification and margin assessment. SIGNIFICANCE: This approach presents an important alternative to current histology techniques, significantly reducing the tissue assessment time, while simultaneously providing the capability to mark and ablate suspicious areas intraoperatively.


Subject(s)
Image Processing, Computer-Assisted/methods , Microscopy, Confocal/instrumentation , Robotic Surgical Procedures/instrumentation , Algorithms , Animals , Breast/diagnostic imaging , Colon/diagnostic imaging , Equipment Design , Humans , Phantoms, Imaging , Swine
11.
Ann Biomed Eng ; 46(10): 1534-1547, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29766347

ABSTRACT

Efficient coupling of soft robotic cardiac assist devices to the external surface of the heart is crucial to augment cardiac function and represents a hurdle to translation of this technology. In this work, we compare various fixation strategies for local and global coupling of a direct cardiac compression sleeve to the heart. For basal fixation, we find that a sutured Velcro band adheres the strongest to the epicardium. Next, we demonstrate that a mesh-based sleeve coupled to the myocardium improves function in an acute porcine heart failure model. Then, we analyze the biological integration of global interface material candidates (medical mesh and silicone) in a healthy and infarcted murine model and show that a mesh interface yields superior mechanical coupling via pull-off force, histology, and microcomputed tomography. These results can inform the design of a therapeutic approach where a mesh-based soft robotic DCC is implanted, allowed to biologically integrate with the epicardium, and actuated for active assistance at a later timepoint. This strategy may result in more efficient coupling of extracardiac sleeves to heart tissue, and lead to increased augmentation of heart function in end-stage heart failure patients.


Subject(s)
Cardiac Surgical Procedures , Heart Failure/surgery , Heart , Robotic Surgical Procedures , Animals , Cardiac Surgical Procedures/instrumentation , Cardiac Surgical Procedures/methods , Disease Models, Animal , Heart Failure/pathology , Robotic Surgical Procedures/instrumentation , Robotic Surgical Procedures/methods , Swine
12.
Soft Robot ; 4(3): 241-250, 2017 Sep.
Article in English | MEDLINE | ID: mdl-29182083

ABSTRACT

Soft robotic devices have significant potential for medical device applications that warrant safe synergistic interaction with humans. This article describes the optimization of an implantable soft robotic system for heart failure whereby soft actuators wrapped around the ventricles are programmed to contract and relax in synchrony with the beating heart. Elastic elements integrated into the soft actuators provide recoiling function so as to aid refilling during the diastolic phase of the cardiac cycle. Improved synchronization with the biological system is achieved by incorporating the native ventricular pressure into the control system to trigger assistance and synchronize the device with the heart. A three-state electro-pneumatic valve configuration allows the actuators to contract at different rates to vary contraction patterns. An in vivo study was performed to test three hypotheses relating to mechanical coupling and temporal synchronization of the actuators and heart. First, that adhesion of the actuators to the ventricles improves cardiac output. Second, that there is a contraction-relaxation ratio of the actuators which generates optimal cardiac output. Third, that the rate of actuator contraction is a factor in cardiac output.


Subject(s)
Heart Failure/therapy , Heart-Assist Devices , Heart/physiology , Robotics/instrumentation , Animals , Biomechanical Phenomena , Biomedical Engineering , Cardiac Output , Disease Models, Animal , Heart Failure/physiopathology , Humans , Myocardial Contraction , Swine
13.
Int J Med Robot ; 13(4)2017 Dec.
Article in English | MEDLINE | ID: mdl-29105982

ABSTRACT

BACKGROUND: Recent studies have suggested that the use of robotic surgery for prostatectomy has been increasing, but characterization of the diffusion of robotic surgery in other procedures has not been available. METHODS: Data were analysed for the years 2006-2014 using hospital episode statistics (HES), a database of all admissions to National Health Service (NHS) hospitals in England. OPCS codes were used to determine the annual number of prostatectomy, partial nephrectomy, and total abdominal hysterectomy procedures. Concurrent OPCS codes were then used to identify whether these procedures were robotic, conventional laparoscopic or open surgery. RESULTS: The proportion of robotic cases varied depending on the surgical procedure. Diffusion of robotic surgery was relatively rapid in prostatectomy, moderate in partial nephrectomy, and slow in total abdominal hysterectomy. CONCLUSIONS: Although high institutional cost might explain the earliest delays in diffusion, this barrier does not fully account for the different rates of diffusion among surgical procedures.


Subject(s)
Hysterectomy/methods , Nephrectomy/methods , Prostatectomy/methods , Robotic Surgical Procedures/trends , Diffusion of Innovation , England , Female , Humans , Hysterectomy/instrumentation , Male , National Health Programs , Nephrectomy/instrumentation , Prostatectomy/instrumentation , Regression Analysis , Retrospective Studies , Robotic Surgical Procedures/methods , Robotics , Time Factors
14.
Ann Biomed Eng ; 45(9): 2222-2233, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28512702

ABSTRACT

We introduce an implantable intracardiac soft robotic right ventricular ejection device (RVED) for dynamic approximation of the right ventricular (RV) free wall and the interventricular septum (IVS) in synchrony with the cardiac cycle to augment blood ejection in right heart failure (RHF). The RVED is designed for safe and effective intracardiac operation and consists of an anchoring system deployed across the IVS, an RV free wall anchor, and a pneumatic artificial muscle linear actuator that spans the RV chamber between the two anchors. Using a ventricular simulator and a custom controller, we characterized ventricular volume ejection, linear approximation against different loads and the effect of varying device actuation periods on volume ejection. The RVED was then tested in vivo in adult pigs (n = 5). First, we successfully deployed the device into the beating heart under 3D echocardiography guidance (n = 4). Next, we performed a feasibility study to evaluate the device's ability to augment RV ejection in an experimental model of RHF (n = 1). RVED actuation augmented RV ejection during RHF; while further chronic animal studies will provide details about the efficacy of this support device. These results demonstrate successful design and implementation of the RVED and its deployment into the beating heart. This soft robotic ejection device has potential to serve as a rapidly deployable system for mechanical circulatory assistance in RHF.


Subject(s)
Echocardiography, Three-Dimensional , Heart Failure , Robotics , Stroke Volume , Animals , Disease Models, Animal , Female , Heart Failure/diagnostic imaging , Heart Failure/physiopathology , Heart Failure/therapy , Humans , Robotics/instrumentation , Robotics/methods , Swine
15.
Mol Reprod Dev ; 84(7): 596-613, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28464323

ABSTRACT

Ssm1b (Strain-specific modifier of DNA methylation 1b) is a Krüppel-associated box (KRAB) zinc finger gene that promotes CpG methylation in the mouse transgene HRD (Heavy chain enhancer, rearrangement by deletion). We report here that Ssm1b expression and concomitant HRD methylation are also present in the male and female germ cells of adult mice. Ssm1b is expressed in both diploid (2N) and haploid (1N) oocytes, as well as in 1N spermatids and spermatozoa, but not in 2N spermatogonia. Interestingly, Ssm1b mRNA is not detected in any other adult mouse organ examined, although Ssm1-family mRNAs are highly expressed in the heart. Reflecting strain specificity, Ssm1b expression and HRD methylation are not observed in early-stage C3H/HeJ mouse embryos; however, an Ssm1b-like gene that closely resembles an Ssm1b-like gene previously found in wild-derived mice is expressed in cultured embryonic stem cells derived from C3H/HeJ embryos, suggesting that culture conditions affect its expression. Collectively, this work demonstrates that HRD methylation by Ssm1b is more temporally restricted during spermatogenesis compared to oogenesis, and is altered when embryonic stem cells are cultured from C3H/HeJ inner cell mass cells.


Subject(s)
DNA-Binding Proteins/biosynthesis , Embryo, Mammalian/metabolism , Embryonic Germ Cells/metabolism , Gene Expression Regulation, Developmental/physiology , Oocytes/metabolism , Spermatids/metabolism , Spermatogonia/metabolism , Animals , Embryo, Mammalian/cytology , Embryonic Germ Cells/cytology , Female , Male , Mice , Oocytes/cytology , Organ Specificity/physiology , Spermatids/cytology , Spermatogonia/cytology
16.
Ann Biomed Eng ; 45(5): 1315-1327, 2017 05.
Article in English | MEDLINE | ID: mdl-28181002

ABSTRACT

Despite the increasing popularity of endovascular intervention in clinical practice, there remains a lack of objective and quantitative metrics for skill evaluation of endovascular techniques. Data relating to the forces exerted during endovascular procedures and the behavioral patterns of endovascular clinicians is currently limited. This research proposes two platforms for measuring tool forces applied by operators and contact forces resulting from catheter-tissue interactions, as a means of providing accurate, objective metrics of operator skill within a realistic simulation environment. Operator manipulation patterns are compared across different experience levels performing various complex catheterization tasks, and different performance metrics relating to tool forces, catheter motion dynamics, and forces exerted on the vasculature are extracted. The results depict significant differences between the two experience groups in their force and motion patterns across different phases of the procedures, with support vector machine (SVM) classification showing cross-validation accuracies as high as 90% between the two skill levels. This is the first robust study, validated across a large pool of endovascular specialists, to present objective measures of endovascular skill based on exerted forces. The study also provides significant insights into the design of optimized metrics for improved training and performance assessment of catheterization tasks.


Subject(s)
Catheterization , Clinical Competence , Endovascular Procedures , Models, Theoretical , Motion , Support Vector Machine , Humans
17.
Sci Transl Med ; 9(373)2017 01 18.
Article in English | MEDLINE | ID: mdl-28100834

ABSTRACT

There is much interest in form-fitting, low-modulus, implantable devices or soft robots that can mimic or assist in complex biological functions such as the contraction of heart muscle. We present a soft robotic sleeve that is implanted around the heart and actively compresses and twists to act as a cardiac ventricular assist device. The sleeve does not contact blood, obviating the need for anticoagulation therapy or blood thinners, and reduces complications with current ventricular assist devices, such as clotting and infection. Our approach used a biologically inspired design to orient individual contracting elements or actuators in a layered helical and circumferential fashion, mimicking the orientation of the outer two muscle layers of the mammalian heart. The resulting implantable soft robot mimicked the form and function of the native heart, with a stiffness value of the same order of magnitude as that of the heart tissue. We demonstrated feasibility of this soft sleeve device for supporting heart function in a porcine model of acute heart failure. The soft robotic sleeve can be customized to patient-specific needs and may have the potential to act as a bridge to transplant for patients with heart failure.


Subject(s)
Heart Failure/physiopathology , Heart Failure/therapy , Heart-Assist Devices , Heart/physiology , Robotics , Animals , Female , Heart Function Tests , Humans , Inflammation , Motion , Rats , Rats, Sprague-Dawley , Silicones/chemistry , Swine , X-Ray Microtomography
18.
Sci Robot ; 2(12)2017 11 22.
Article in English | MEDLINE | ID: mdl-33157903

ABSTRACT

Previous soft robotic ventricular assist devices have generally targeted biventricular heart failure and have not engaged the interventricular septum that plays a critical role in blood ejection from the ventricle. We propose implantable soft robotic devices to augment cardiac function in isolated left or right heart failure by applying rhythmic loading to either ventricle. Our devices anchor to the interventricular septum and apply forces to the free wall of the ventricle to cause approximation of the septum and free wall in systole and assist with recoil in diastole. Physiological sensing of the native hemodynamics enables organ-in-the-loop control of these robotic implants for fully autonomous augmentation of heart function. The devices are implanted on the beating heart under echocardiography guidance. We demonstrate the concept on both the right and the left ventricles through in vivo studies in a porcine model. Different heart failure models were used to demonstrate device function across a spectrum of hemodynamic conditions associated with right and left heart failure. These acute in vivo studies demonstrate recovery of blood flow and pressure from the baseline heart failure conditions. Significant reductions in diastolic ventricle pressure were also observed, demonstrating improved filling of the ventricles during diastole, which enables sustainable cardiac output.

19.
PLoS One ; 11(9): e0162232, 2016.
Article in English | MEDLINE | ID: mdl-27622693

ABSTRACT

Residents are required to learn a multitude of skills during their microsurgical training. One such skill is the judicious application of force when handling delicate tissue. An instrument has been developed that indicates to the surgeon when a force threshold has been exceeded by providing vibrotactile feedback. The objective of this study was to validate the use of this "smart" force-limiting instrument for microsurgery. A laboratory and an in vivo experiment were performed to evaluate the force-limiting instrument. In the laboratory experiment, twelve novice surgeons were randomly allocated to use either the force-limiting instrument or a standard instrument. Surgeons were then asked to perform microsurgical dissection in a model. In the in vivo experiment, an intermediate surgeon performed microsurgical dissection in a stepwise fashion, alternating every 30 seconds between use of the force-limiting instrument and a standard instrument. The primary outcomes were the forces exerted and the OSATS scores. In the laboratory experiment, the maximal forces exerted by novices using the force-limiting instrument were significantly less than using a standard instrument, and were comparable to intermediate and expert surgeons (0.637N versus 4.576N; p = 0.007). In the in vivo experiment, the maximal forces exerted with the force-limiting instrument were also significantly less than with a standard instrument (0.441N versus 0.742N; p <0.001). Notably, use of the force-limiting instrument did not significantly impede the surgical workflow as measured by the OSATS score (p >0.1). In conclusion, the development and use of this force-limiting instrument in a clinical setting may improve patient safety.


Subject(s)
Microsurgery/instrumentation , Surgical Instruments , Adult , Dissection/instrumentation , Dissection/methods , Feedback , Female , Humans , Male , Stress, Mechanical , Young Adult
20.
BMJ ; 353: i2587, 2016 May 20.
Article in English | MEDLINE | ID: mdl-27207165

ABSTRACT

OBJECTIVE:  To investigate the regulatory approval of new medical devices. DESIGN:  Cross sectional study of new medical devices reported in the biomedical literature. DATA SOURCES:  PubMed was searched between 1 January 2000 and 31 December 2004 to identify clinical studies of new medical devices. The search was carried out during this period to allow time for regulatory approval. ELIGIBILITY CRITERIA FOR STUDY SELECTION:  Articles were included if they reported a clinical study of a new medical device and there was no evidence of a previous clinical study in the literature. We defined a medical device according to the US Food and Drug Administration as an "instrument, apparatus, implement, machine, contrivance, implant, in vitro reagent, or other similar or related article." MAIN OUTCOME MEASURES:  Type of device, target specialty, and involvement of academia or of industry for each clinical study. The FDA medical databases were then searched for clearance or approval relevant to the device. RESULTS:  5574 titles and abstracts were screened, 493 full text articles assessed for eligibility, and 218 clinical studies of new medical devices included. In all, 99/218 (45%) of the devices described in clinical studies ultimately received regulatory clearance or approval. These included 510(k) clearance for devices determined to be "substantially equivalent" to another legally marketed device (78/99; 79%), premarket approval for high risk devices (17/99; 17%), and others (4/99; 4%). Of these, 43 devices (43/99; 43%) were actually cleared or approved before a clinical study was published. CONCLUSIONS:  We identified a multitude of new medical devices in clinical studies, almost half of which received regulatory clearance or approval. The 510(k) pathway was most commonly used, and clearance often preceded the first published clinical study.


Subject(s)
Device Approval/legislation & jurisprudence , Equipment and Supplies/standards , Academies and Institutes , Clinical Studies as Topic , Cross-Sectional Studies , Health Care Sector , Humans , Prostheses and Implants/standards
SELECTION OF CITATIONS
SEARCH DETAIL
...