Search

Background: Point-of-care ultrasound (POCUS) has emerged as an essential bedside tool for clinicians, but lack of access to ultrasound equipment has been a top barrier to POCUS use. Recently, several handheld ultrasound devices ("handhelds") have become available, and clinicians are seeking data to guide purchasing decisions. Few comparative studies of different handhelds have been done. We conducted a cross-sectional study comparing 6 handhelds readily available in the United States (Butterfly iQ +  ™ by Butterfly Network Inc.; Clarius ™ by Clarius Mobile Health; Kosmos ™ by EchoNous; TE Air ™ by Mindray; Vscan Air ™ SL and CL by General Electric; and Lumify ™ by Philips Healthcare). A multi-specialty group of physician POCUS experts (n = 35) acquired three standard ultrasound views (abdominal right upper quadrant, cardiac apical 4-chamber, and superficial neck and lung views) in random order on the same standardized patients and rated the image quality. Afterward, a final survey of the overall ease of use, image quality, and satisfaction of each handheld was completed., Results: Thirty-five POCUS experts specializing in internal medicine/hospital medicine, critical care, emergency medicine, and nephrology acquired and rated right upper quadrant, apical 4-chamber, and superficial neck and lung views with 6 different handhelds. For image quality, the highest-rated handhelds were Vscan Air ™ for the right upper quadrant view, Mindray TE Air ™ for the cardiac apical 4-chamber view, and Lumify ™ for superficial views of the neck and lung. Overall satisfaction with image quality was highest with Vscan Air ™ , Lumify ™ , and Mindray, while overall satisfaction with ease of use was highest with Vscan Air ™ . The 5 most desirable characteristics of handhelds were image quality, ease of use, portability, probe size, and battery life. Ultimately, all 6 handhelds had notable advantages and disadvantages, with no single device having all desired qualities or features., Conclusions: The overall satisfaction with image quality was rated highest with Vscan Air ™ , Lumify ™ , and Mindray TE Air ™ when acquiring right upper quadrant, apical 4-chamber, and superficial neck and lung views. No single handheld was perceived to be superior in image quality for all views. Vscan Air ™ was rated highest for overall ease of use and was the most preferred handheld for purchase by POCUS experts., (© 2024. The Author(s).)

This work presents a unique approach to the design, fabrication, and characterization of paper-based origami robotic systems consisting of stackable pneumatic actuators. These paper-based actuators (PBAs) use materials with high elastic modulus-to-mass ratios, accordion-like structures, and direct coupling with pneumatic pressure for extension and bending. The study contributes to the scientific and engineering understanding of foldable components under applied pneumatic pressure by constructing stretchable and flexible structures with intrinsically nonstretchable materials. Experiments showed that a PBA possesses a power-to-mass ratio greater than 80 W/kg, which is more than four times that of human muscle. This work also illustrates the stackability and functionality of PBAs by two prototypes: a parallel manipulator and a legged locomotor. The manipulator consisting of an array of PBAs can bend in a specific direction with the corresponding actuator inflated. In addition, the stacked actuators in the manipulator can rotate in opposite directions to compensate for relative rotation at the ends of each actuator to work in parallel and manipulate the platform. The locomotor rotates the PBAs to apply and release contact between the feet and the ground. Furthermore, a numerical model developed in this work predicts the mechanical performance of these inflatable actuators as a function of dimensional specifications and folding patterns. Overall, we use stacked origami actuators to implement functionalities of manipulation, gripping, and locomotion as conventional robotic systems. Future origami robots made of paper-like materials may be suitable for single use in contaminated or unstructured environments or low-cost educational materials.

An increasing number of patients with abdominal aortic aneurysms (AAAs) are undergoing endovascular aortic repair (EVAR) instead of open surgery. These patients require lifelong surveillance, and the follow-up imaging modality of choice has been traditionally computed tomography angiography (CTA). Repetitive CTA imaging is associated with cumulative radiation exposure and requires the administration of multiple doses of nephrotoxic contrast agents. Contrast-enhanced ultrasound (CEUS) has emerged as an alternative strategy in the follow-up of patients with EVAR and demonstrates high sensitivity and specificity for detection of endoleaks. In fact, a series of studies have shown that CEUS is at least performing equal to computed tomography for the detection and classification of endoleaks. This article summarizes current evidence of CEUS after EVAR and demonstrates its usefulness via various patient cases.

Nature has the exquisite ability to design specific surface patterns and topologies on both the macro- and nanolength scales that relate to precise functions. Following a biomimetic approach, we have engineered fully synthetic nanoparticles that are able to self-organize their surface into controlled domains. We focused on polymeric vesicles or "polymersomes"; enclosed membranes formed via self-assembly of amphiphilic block copolymers in water. Exploiting the intrinsic thermodynamic tendency of dissimilar polymers to undergo phase separation, we mixed different vesicle-forming block copolymers in various proportions in order to obtain a wide range of polymersomes with differing surface domains. Using a combination of confocal laser scanning microscopy studies of micrometer-sized polymersomes, and electron microscopy, atomic force microscopy, and fluorescence spectroscopy on nanometer-sized polymersomes, we find that the domains exhibit similar shapes on both the micro- and nanolength scales, with dimensions that are linearly proportional to the vesicle diameter. Finally, we demonstrate that such control over the surface "patchiness" of these polymersomes determines their cell internalization kinetics for live cells.

The bulk mechanical properties of soft materials have been studied widely, but it is unclear to what extent macroscopic behavior is reflected in nanomechanics. Using an atomic force microscopy (AFM) imaging method called force spectroscopy mapping (FSM), it is possible to map the nanoscopic spatial distribution of Young's modulus, i.e. "stiffness," and determine if soft or stiff polymer domains exist to correlate nano- and macro-mechanics. Two model hydrogel systems typically used in cell culture and polymerized by a free radical polymerization process, i.e. poly (vinyl pyrrolidone) (PVP) and poly(acrylamide) (PAam) hydrogels, were found to have significantly different nanomechanical behavior despite relatively similar bulk stiffness and roughness. PVP gels contained a large number of soft and stiff nanodomains, and their size was inversely related to crosslinking density and changes in crosslinking efficiency within the hydrogel. In contrast, PAam gels displayed small nanodomains occuring at low frequency, indicating relatively uniform polymerization. Given the responsiveness of cells to changes in gel stiffness, inhomogeneities found in the PVP network indicate that careful nanomechanical characterization of polymer substrates is necessary to appreciate complex cell behavior.

Cell cytosol and the different subcellular organelles house the most important biochemical processes that control cell functions. Effective delivery of bioactive agents within cells is expected to have an enormous impact on both gene therapy and the future development of new therapeutic and/or diagnostic strategies based on single-cell-bioactive-agent interactions. Herein a biomimetic nanovector is reported that is able to enter cells, escape from the complex endocytic pathway, and efficiently deliver actives within clinically relevant cells without perturbing their metabolic activity. This nanovector is based on the pH-controlled self-assembly of amphiphilic copolymers into nanometer-sized vesicles (or polymersomes). The cellular-uptake kinetics can be regulated by controlling the surface chemistry, the polymersome size, and the polymersome surface topology. The latter is controlled by the extent of polymer-polymer phase separation within the external envelope of the polymersome.

The purpose of this pilot study was to examine possible neurotoxic effects of prenatal methamphetamine (Meth) exposure on the developing brain and on cognition. Meth-exposed children (n=13) and unexposed control subjects (n=15) were evaluated with MRI. Global brain volumes and regional brain structures were quantified. Ten Meth-exposed and nine unexposed children also completed neurocognitive assessments. Meth-exposed children scored lower on measures of visual motor integration, attention, verbal memory and long-term spatial memory. There were no differences among the groups in motor skills, short delay spatial memory or measures of non-verbal intelligence. Despite comparable whole brain volumes in each group, the Meth-exposed children had smaller putamen bilaterally (-17.7%), smaller globus pallidus (left: -27%, right: 30%), smaller hippocampus volumes (left: -19%, right: -20%) and a trend for a smaller caudate bilaterally (-13%). The reduction in these brain structures correlated with poorer performance on sustained attention and delayed verbal memory. No group differences in volumes were noted in the thalamus, midbrain or the cerebellum. In summary, compared with the control group, children exposed to Meth prenatally exhibit smaller subcortical volumes and associated neurocognitive deficits. These preliminary findings suggest prenatal Meth exposure may be neurotoxic to the developing brain.

Purpose: Acute postoperative seizures (APOSs) are those that occur in the first 7 to 10 days after surgery, and previous studies in temporal lobe epilepsy patients support the notion that APOSs may foretell failure of long-term seizure control. It is unknown whether APOSs also predict seizure outcome or hospital course after hemispherectomy., Methods: Hemispherectomy patients (n = 114) were studied retrospectively and subdivided into the following groups: No APOSs, 1 to 5 APOSs, or >5 APOSs. Intensive care unit (ICU) nursing staff or family members reported and described the APOS events. APOS categories were compared with pre- and postsurgery clinical variables abstracted from the medical record., Results: APOSs occurred in 22.6% of hemispherectomy patients. Compared with the 0 and 1 to 5 APOS groups, patients with >5 APOS showed (a) longer seizure durations before surgery, (b) longer hospitalizations, (c) later oral food intake, (d) more frequent lumbar punctures, (e) worse seizure control at 0.5 and 1 year after surgery, (f) more antiepileptic drug (AED) use at 2 and 5 years after surgery, and (g) higher reoperation rate. No similar differences were found between the 0 and 1 to 5 APOS groups. The day of the APOS, whether the APOS was typical of preoperative seizures, and postsurgery scalp EEG did not predict long-term seizure control. APOS patients in the 1 to 5 and >5 groups had lower pre- and postsurgery Vineland developmental quotients compared with those without an APOS., Conclusions: Hemispherectomy patients with >5 APOSs had a more prolonged and complicated hospital course and worse postsurgery seizure control, more AED use, and higher reoperation rate than did patients with 0 or 1 to 5 APOSs. Thus the number of APOSs was a predictor of postsurgery seizure control and can be used to counsel patients and families about prognosis after hemispherectomy.

Unlabelled: The most appropriate time to consider cortical resection to treat medically intractable infantile spasms has not been clearly defined. The risks that need to be reconciled to make this decision are: What is the risk of loss of developmental potential if surgery is delayed too long versus what is the risk of unnecessary surgery if it is done too soon. We propose that, in addition to evaluation of seizures, developmental assessment is a key factor in the surgical decision. The case report illustrates this concept., Case Report: HC had onset of seizures at 9 days of age and developed infantile spasms due to mild right hemimegancephaly. At 19 months, she was having up to 50 seizures/day and was evaluated and approved for right hemispherectomy but surgery was delayed. Despite the seizures, her development had been much better than most patients with hemimegencephaly and infantile spasms. At 25 months her seizure control was much improved but she had several seizures/week. EcoG at the time of surgery did not demonstrate the usual abnormalities so no resection was performed. She has had only 5 seizures in the 2(1/2) year since., Conclusions: (a) Hemimegalencephaly is not always associated with severe mental retardation; (b) normal or near-normal development may, in some cases, indicate the possibility of medical control of seizures as the child grows; (c) a localized developmental brain abnormality in a child with intractable seizures should not necessarily lead to cortical resection; and (d) when a child meets developmental milestones, it may be appropriate to delay surgical intervention.

Pseudoaneurysm formation is a rare complication of knee arthroscopy. Cases reported in the literature have involved the popliteal, superior and inferior medial geniculate, and the inferior lateral geniculate arteries. These cases have all been described as presenting within 2 to 3 weeks of the arthroscopic procedure. Described here are two unique cases, the first a delayed presentation and the second involving the recurrent anterior tibial artery.

We present one case of pulmonary edema following intravenous naloxone administration for antagonism of residual narcotic drugs. The patient was a young man without cardiopulmonary or neurologic disease. Pathogenesis results from a massive sympathetic discharge which leads to neurogenic pulmonary edema.

This study was originally presented at the American College of Sports Medicine annual meeting in San Diego, CA, 1984. Following repair of the anterior cruciate ligament, it is fairly typical for a patient to return to activity at approximately 12 months postsurgery. The purpose of the study was to quantify quadriceps size and function at 1 year postsurgery. Bilateral isokinetic torque measurements, tomographic scans, muscle biopsies, and anthropometrics were performed on 13 patients (3 females, 10 males) at 13 months post-surgery. The operative leg was 3% smaller in circumference, 10% smaller in total muscle area, 12% smaller in quadriceps area (all p < 0.05) and had a 9% larger subcutaneous fat area (p = 0.06). No difference in hamstrings area was seen. Isokinetic torques for the quadriceps were reduced by 11-15% in the operative leg (p < .05) with no difference seen between the hamstrings torques. Types I and II fibers were clinically smaller in both legs with the type II fibers being significantly (p < 0.05) reduced in the operative leg. It was concluded that 1) leg circumference was a poor indicator of muscle size due to the selective fat deposition in the operative leg, 2) the cross-sectional area of muscle was proportional to isokinetic torque at 240/sec, and 3) there were clinically and statistically significant isokinetic torque differences between quadriceps 13 months post-surgery.J Orthop Sports Phys Ther 1988;9(7):245-249.