Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
1.
Adv Intell Syst ; 4(10)2022 Oct.
Article in English | MEDLINE | ID: mdl-38463142

ABSTRACT

Swimming microrobots are increasingly developed with complex materials and dynamic shapes and are expected to operate in complex environments in which the system dynamics are difficult to model and positional control of the microrobot is not straightforward to achieve. Deep reinforcement learning is a promising method of autonomously developing robust controllers for creating smart microrobots, which can adapt their behavior to operate in uncharacterized environments without the need to model the system dynamics. This article reports the development of a smart helical magnetic hydrogel microrobot that uses the soft actor critic reinforcement learning algorithm to autonomously derive a control policy which allows the microrobot to swim through an uncharacterized biomimetic fluidic environment under control of a time varying magnetic field generated from a three-axis array of electromagnets. The reinforcement learning agent learned successful control policies from both state vector input and raw images, and the control policies learned by the agent recapitulated the behavior of rationally designed controllers based on physical models of helical swimming microrobots. Deep reinforcement learning applied to microrobot control is likely to significantly expand the capabilities of the next generation of microrobots.

2.
Micromachines (Basel) ; 11(10)2020 Oct 20.
Article in English | MEDLINE | ID: mdl-33092054

ABSTRACT

An evolving understanding of disease pathogenesis has compelled the development of new drug delivery approaches. Recently, bioinspired microrobots have gained traction as drug delivery systems. By leveraging the microscale phenomena found in physiological systems, these microrobots can be designed with greater maneuverability, which enables more precise, controlled drug release. Their function could be further improved by testing their efficacy in physiologically relevant model systems as part of their development. In parallel with the emergence of microscale robots, organ-on-a-chip technologies have become important in drug discovery and physiological modeling. These systems reproduce organ-level functions in microfluidic devices, and can also incorporate specific biological, chemical, and physical aspects of a disease. This review highlights recent developments in both microrobotics and organ-on-a-chip technologies and envisions their combined use for developing future drug delivery systems.

3.
Sci Rep ; 10(1): 1543, 2020 01 31.
Article in English | MEDLINE | ID: mdl-32005961

ABSTRACT

Microfluidic technologies are frequently employed as point-of-care diagnostic tools for improving time-to-diagnosis and improving patient outcomes in clinical settings. These microfluidic devices often are designed to operate with peripheral equipment for liquid handling that increases the cost and complexity of these systems and reduces their potential for widespread adoption in low resource healthcare applications. Here, we present a low-cost (~$120), open-source peristaltic pump constructed with a combination of three dimensional (3D)-printed parts and common hardware, which is amenable to deployment with microfluidic devices for point-of-care diagnostics. This pump accepts commonly available silicone rubber tubing in a range of sizes from 1.5 to 3 mm, and is capable of producing flow rates up to 1.6 mL min-1. This device is programmed with an Arduino microcontroller, allowing for custom flow profiles to fit a wide range of low volume liquid handling applications including precision liquid aliquoting, flow control within microfluidics, and generation of physiologically relevant forces for studying cellular mechanobiology within microfluidic systems.


Subject(s)
Infusion Pumps, Implantable/standards , Ionic Liquids/metabolism , Lab-On-A-Chip Devices/standards , Point-of-Care Systems/standards , Specimen Handling/methods , Computers , Humans , Microfluidics/methods , Peristalsis , Printing, Three-Dimensional
4.
Prax Kinderpsychol Kinderpsychiatr ; 66(2): 104-120, 2017 Feb.
Article in German | MEDLINE | ID: mdl-28142632

ABSTRACT

Dialectical Behavioral Therapy for Male Adolescents with Borderline Symptomatology The efficacy of Dialectical Behavior Therapy for adolescents (DBT-A) in patients with borderline symptomatology has mainly been shown in female adolescents. However, male adolescents with borderline symptoms are characterized by more aggressive, disruptive, and antisocial behavior. Therefore, the efficacy of the DBT-A has to be investigated in male adolescents. The DBT-A manual was adopted for male adolescents in an inpatient setting. The program has been investigated using a pre-post design in seven male adolescents (on average 14 years of age) with an average of five borderline symptoms according to DSM-IV. Criteria for outcome are symptoms of psychopathology, emotion regulation, aggressive, and self-injurious behavior. After treatment a reduction in aggressive behavior (pre-post effect size d = 1.18) and an improvement in adaptive emotion regulation (d = 0.65) were shown. No improvement could be shown in general symptoms of psychopathology (d = 0.02). The results of these case studies of DBT-A in male adolescents are promising. However, further RCTs with larger sample sizes and a control group will be required.


Subject(s)
Borderline Personality Disorder/psychology , Borderline Personality Disorder/therapy , Cognitive Behavioral Therapy/methods , Adolescent , Aggression/psychology , Antisocial Personality Disorder/diagnosis , Antisocial Personality Disorder/psychology , Antisocial Personality Disorder/therapy , Attention Deficit and Disruptive Behavior Disorders/diagnosis , Attention Deficit and Disruptive Behavior Disorders/psychology , Attention Deficit and Disruptive Behavior Disorders/therapy , Borderline Personality Disorder/diagnosis , Emotional Intelligence , Germany , Humans , Male , Manuals as Topic , Patient Admission , Self-Injurious Behavior/diagnosis , Self-Injurious Behavior/psychology , Self-Injurious Behavior/therapy , Treatment Outcome
5.
Consult Pharm ; 28(2): 99-109, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23395810

ABSTRACT

OBJECTIVE: To determine the utility (i.e., positive predictive value [PPV] and time requirement) of an adverse drug event (ADE) trigger tool in Veterans Affairs (VA) nursing facilities and to describe the most common types of potential ADEs detected with the trigger tool. DESIGN: Retrospective chart review. SETTING/PATIENTS: Veterans residing in three VA nursing facilities between September 29, 2010, and October 29, 2010. MEASUREMENT: We used the Institute for Healthcare Improvement-endorsed nursing facility ADE trigger tool, modified to enhance its clinical relevance to detect potential ADEs. Electronic medical records were screened to identify residents with one or more abnormal laboratory values specified in the trigger tool. MAIN OUTCOME MEASURES: A potential ADE was defined as the concurrent administration of medication that could cause the abnormal laboratory value. An overall PPV, or proportion of residents with an abnormal laboratory value who had a potential ADE, and average time required to complete each trigger tool assessment, were calculated. RESULTS: Among 321 veterans, 50.5% (n = 162) had at least one abnormal laboratory value contained in the trigger tool. Ninety-nine potential ADEs involving 146 medications were detected in 65 veterans. The overall PPV of the ADE trigger tool was 40.1% (65/162), and the average time to complete resident assessments was 8.8 (standard deviation ± 5.7) minutes. The most common potential ADEs were acute kidney injury (n = 30 residents), hypokalemia (n = 18), hypoglycemia (n = 13), and hyperkalemia (n = 10). CONCLUSIONS: The modified nursing facility trigger tool was shown to be an effective and efficient method for detecting potential ADEs.


Subject(s)
Drug-Related Side Effects and Adverse Reactions , Drug-Related Side Effects and Adverse Reactions/diagnosis , Nursing Homes , Aged , Aged, 80 and over , Drug-Related Side Effects and Adverse Reactions/epidemiology , Electronic Health Records , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Retrospective Studies , Time Factors , United States , United States Department of Veterans Affairs , Veterans
6.
PLoS One ; 7(9): e45901, 2012.
Article in English | MEDLINE | ID: mdl-23029302

ABSTRACT

We studied diet variation in an omnivorous fish across its range, which allowed us to test predictions about the effect of ocean temperature and habitat on herbivory. Throughout most of its geographic range, from Southern California to central Baja California, the opaleye (Girella nigricans) fed primarily on red and green algae, but there was significant variation in the amount of algal material in the diet among sites. The proportion of algal material in the diet was related to habitat, with algae making up a larger proportion of a fish's diet in algal-dominated habitats than in urchin barrens. Independent of habitat, the proportion of algal material in the diet increased with environmental temperature. Analyses of stable isotopes revealed similar changes in trophic position and confirmed that these associations with diet persisted over relatively long time scales. The shift to a more herbivorous diet at warmer temperatures is in agreement with past laboratory studies on this species that show a diet-dependent change in performance with temperature and can indicate a diet shift across the species' geographic range to meet its physiological demands. A possible plastic response to herbivory was a longer gut relative to body size. The results of this study are consistent with past findings that associate temperature with increases in the relative diversity of herbivorous fishes in tropical parts of the ocean.


Subject(s)
Diet , Herbivory/physiology , Perciformes/physiology , Analysis of Variance , Animals , California , Chlorophyta , Ecosystem , Pacific Ocean , Rhodophyta
7.
Vector Borne Zoonotic Dis ; 12(7): 575-82, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22607081

ABSTRACT

Reptiles account for ∼10% of live animal shipments imported to the United States (U.S.), the majority of which are sold in the pet trade. Characterizing Salmonella shedding by imported reptiles is of value to public health, the pet industry, and veterinary medicine. Here we report results of a pilot survey of Salmonella serotypes isolated from wild-caught Indonesian Tokay geckos (Gekko gecko) imported to the U.S. Upon arrival, the geckos were individually housed until a fecal sample was acquired for Salmonella culture. The geckos were divided into three groups with variable numbers to investigate density effects. A second group was imported after 3 months and combined with the previous groups. A total of 88 Salmonella isolates were obtained from 110 geckos surveyed, representing 14 serogroups and 17 unique serotypes. Group prevalence ranged from 31-73%. A significant increase in prevalence and a change in serotype richness were detected between the time of import and 6 months later at necropsy. Six isolates (6.8%) expressed resistance to more than one antibiotic. All S. enterica subsp. enterica Adelaide isolates were resistant to nalidixic acid and sulfisoxazole, one S. enterica subsp. arizonae 61:k:z35 isolate was resistant to ampicillin and sulfisoxazole, and another 61:k:z35 isolate was resistant to streptomycin and sulfisoxazole. Forty-three additional isolates expressed resistance only to sulfisoxazole. The mechanisms for increased prevalence and apparent change in serotype richness are unknown, but could be due to stress associated with trade, transport, and captivity, increased transmission from unnaturally high densities, or contact with other species shedding Salmonella along the trade route. Future studies to differentiate the physical, social, and physiological effects of trade-related conditions on Salmonella shedding and transmission among reptiles will benefit the industry by identifying ways to reduce mortality, and safeguard the individuals handling animals along the transport chain and other species encountered en route.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antigens, Bacterial/immunology , Drug Resistance, Multiple, Bacterial , Lizards/microbiology , Salmonella Infections, Animal/microbiology , Salmonella/immunology , Animals , Bacterial Shedding , DNA, Bacterial/genetics , Feces/microbiology , Female , Georgia , Indonesia , Male , Microbial Sensitivity Tests/veterinary , Pilot Projects , Prevalence , Random Allocation , Salmonella/drug effects , Salmonella/genetics , Salmonella/isolation & purification , Salmonella Infections, Animal/epidemiology , Serotyping/veterinary , Stress, Physiological , United States
8.
Int J Med Inform ; 81(12): 842-51, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22534099

ABSTRACT

OBJECTIVE: The purpose of this study was to evaluate ICU nurses' ability to detect patient change using an integrated graphical information display (IGID) versus a conventional tabular ICU patient information display (i.e. electronic chart). DESIGN: Using participants from two different sites, we conducted a repeated measures simulator-based experiment to assess ICU nurses' ability to detect abnormal patient variables using a novel IGID versus a conventional tabular information display. Patient scenarios and display presentations were fully counterbalanced. MEASUREMENTS: We measured percent correct detection of abnormal patient variables, nurses' perceived workload (NASA-TLX), and display usability ratings. RESULTS: 32 ICU nurses (87% female, median age of 29 years, and median ICU experience of 2.5 years) using the IGID detected more abnormal variables compared to the tabular display [F(1, 119)=13.0, p<0.05]. There was a significant main effect of site [F(1, 119)=14.2], with development site participants doing better. There were no significant differences in nurses' perceived workload. The IGID display was rated as more usable than the conventional display [F(1, 60)=31.7]. CONCLUSION: Overall, nurses reported more important physiological information with the novel IGID than tabular display. Moreover, the finding of site differences may reflect local influences in work practice and involvement in iterative display design methodology. Information displays developed using user-centered design should accommodate the full diversity of the intended user population across use sites.


Subject(s)
Data Display , Health Information Systems/statistics & numerical data , Intensive Care Units , Medical Errors/prevention & control , Nursing Staff, Hospital , Adult , Female , Humans , Male , Middle Aged , Perception , User-Computer Interface , Workforce , Workload
9.
Ecohealth ; 6(2): 287-95, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19921487

ABSTRACT

To date, ecologists and conservation biologists have focused much of their attention on the population and ecosystem effects of disease at regional scales and the role that diseases play in global species extinction. Far less research has been dedicated to identifying the effects that diseases can have on local scale species assemblages. We examined the role of infectious disease in structuring local biodiversity. Our intention was to illustrate how variable outcomes can occur by focusing on three case studies: the influence of chestnut blight on forest communities dominated by chestnut trees, the influence of red-spot disease on urchin barrens and kelp forests, and the influence of sylvatic plague on grassland communities inhabited by prairie dogs. Our findings reveal that at local scales infectious disease seems to play an important, though unpredictable, role in structuring species diversity. Through our case studies, we have shown that diseases can cause drastic population declines or local extirpations in keystone species, ecosystem engineers, and otherwise abundant species. These changes in local diversity may be very important, particularly when considered alongside potentially corresponding changes in community structure and function, and we believe that future efforts to understand the importance of disease to species diversity should have an increased focus on these local scales.


Subject(s)
Biodiversity , Plant Diseases , Rodent Diseases , Animals , Endangered Species , Fagaceae/microbiology , Kelp , Mycoses , Plague , Population Dynamics , Sciuridae , Sea Urchins/microbiology , Trees
11.
Int J Cancer ; 124(3): 722-8, 2009 Feb 01.
Article in English | MEDLINE | ID: mdl-18989899

ABSTRACT

To enhance the quality and safety in cancer treatment, and in acknowledgement that medical errors occur, we have established 2 error management systems: one monitors chemotherapy errors, the other records all severe adverse events occurring in chemotherapy-treated cancer patients (SAECTx) in in- and outpatient treatment. These error systems have been implemented by our departmental "Clinical Service Center," a multidisciplinary team which controls all chemotherapy protocols and orders prior to the medication reaching the patient. We performed a prospective cohort study in consecutive cancer patients who received chemotherapies in our department between January 2005 and December 2006. Over this 2-year period, 2,337 patients were treated, with an equal distribution as in- and outpatients: 22,216 consecutive chemotherapy orders were analyzed, of which 83.5% were completely flawless, whereas we detected and corrected medical and administrative errors in 17.1%: in 3.8%, these errors involved the chemotherapy itself, in 4.5% the patient data and in 8.7% missing written informed consent forms. Chemotherapy errors were less frequent in outpatients than inpatients (3.3 vs. 4.5%, respectively). In outpatients, the rate of chemotherapy errors decreased from 4% in 2005 to 2.8% in 2006, but remained stable for inpatients (4.4% 2005 vs. 4.7% 2006). Among a total of 3,792 detected errors, only 3 reached the patient, resulting in an error rate in patients of 0.079%. Therefore, since we detected a substantial number of chemotherapy-related errors and intercepted 99.9%, we recommend our efficient surveillance system as an important safety check, thereby ensuring that chemotherapies are delivered error-free to cancer patients.


Subject(s)
Antineoplastic Agents/adverse effects , Medical Oncology/standards , Medication Errors/prevention & control , Medication Systems, Hospital , Neoplasms/drug therapy , Safety Management/methods , Adolescent , Adult , Aged , Aged, 80 and over , Cohort Studies , Female , Humans , Inpatients , Male , Medical Records Systems, Computerized , Middle Aged , Outpatients
SELECTION OF CITATIONS
SEARCH DETAIL
...