A soft matter computer for soft robots.

Despite the growing interest in soft robotics, little attention has been paid to the development of soft matter computational mechanisms. Embedding computation directly into soft materials is not only necessary for the next generation of fully soft robots but also for smart materials to move beyond stimulus-response relationships and toward the intelligent behaviors seen in biological systems. This article describes soft matter computers (SMCs), low-cost, and easily fabricated computational mechanisms for soft robots. The building block of an SMC is a conductive fluid receptor (CFR), which maps a fluidic input signal to an electrical output signal via electrodes embedded into a soft tube. SMCs could perform both analog and digital computation. The potential of SMCs is demonstrated by integrating them into three soft robots: (i) a Softworm robot was controlled by an SMC that generated the control signals necessary for three distinct gaits; (ii) a soft gripper was given a set of reflexes that could be programmed by adjusting the parameters of the CFR; and (iii) a two-degree of freedom bending actuator was switched between three distinct behaviors by varying only one input parameter. SMCs are a low-cost way to integrate computation directly into soft materials and an important step toward entirely soft autonomous robots.

Implementing computerized technology: an organizational analysis.

Why do some organizations succeed and others fail in implementing the innovations they adopt? To begin to answer this question, the authors studied the implementation of manufacturing resource planning, an advanced computerized manufacturing technology, in 39 manufacturing plants (number of individual respondents = 1,219). The results of the plant-level analyses suggest that financial resource availability and management support for technology implementation engender high-quality implementation policies and practices and a strong climate for implementation, which in turn foster implementation effectiveness--that is, consistent and skilled technology use. Further research is needed to replicate and extend the findings.

Is everyone in agreement? An exploration of within-group agreement in employee perceptions of the work environment.

Multilevel researchers often gather individual-level data to measure group-level constructs. Within-group agreement is a key consideration in the measurement of such constructs, yet antecedents of within-group agreement have been little studied. The authors found that group member social interaction and work interdependence were significantly positively related to within-group agreement regarding perceptions of the work environment. Demographic heterogeneity was not significantly related to within-group agreement. Survey wording showed a complex relationship to agreement. Both evaluative items and socially undesirable items generated high within-group agreement. The use of a group rather than individual referent increased within-group agreement in response to descriptive items but decreased within-group agreement in response to evaluative items. Items with a group referent showed greater between-group variability than items with an individual referent.

Eyeing the ED's open door: how case managers can reduce unnecessary admissions.

More than one-third of all hospital admissions originate from the emergency department (ED). ED case managers maximize the quality of care and control ED admissions by verifying admission criteria, finding alternatives to inappropriate or social admissions, and identifying high-risk discharge factors.

Eyeing the ED's open door.

More than one-third of all hospital admissions originate from the emergency department (ED). ED case managers maximize the quality of care and control ED admissions by verifying admission criteria, finding alternatives to inappropriate or social admissions, and identifying high-risk discharge factors.

Benchmarking and quality improvement: the Harvard Emergency Department Quality Study.

PURPOSE: To determine whether feedback of comparative information was associated with improvement in medical record and patient-based measures of quality in emergency departments. SUBJECTS AND METHODS: During 1-month study periods in 1993 and 1995, all medical records for patients who presented to five Harvard teaching hospital emergency departments with one of six selected chief complaints (abdominal pain, shortness of breath, chest pain, hand laceration, head trauma, or vaginal bleeding) were reviewed for the percent compliance with process-of-care guidelines. Patient-reported problems and patient ratings of satisfaction with emergency department care were collected from eligible patients using patient questionnaires. After reviewing benchmark information, emergency department directors designed quality improvement interventions to improve compliance with the process-of-care guidelines and improve patient-reported quality measures. RESULTS: In the preintervention period, 4,876 medical records were reviewed (99% of those eligible), 2,327 patients completed on-site questionnaires (84% of those eligible), and 1,386 patients completed 10-day follow-up questionnaires (80% of a random sample of eligible participants). In the postintervention period, 6,005 medical records were reviewed (99% of those eligible), 2,899 patients completed on-site questionnaires (84% of those eligible), and 2,326 patients completed 10-day follow-up questionnaires (80% of all baseline participants). In multivariate analyses, adjusting for age, urgency, chief complaint, and site, compliance with process-of-care guidelines increased from 55.9% (preintervention) to 60.4% (postintervention, P = 0.0001). We also found a 4% decrease (from 24% to 20%) in the rate of patient-reported problems with emergency department care (P = 0.0001). There were no significant improvements in patient ratings of satisfaction. CONCLUSION: Feedback of benchmark information and subsequent quality improvement efforts led to small, although significant, improvement in compliance with process-of-care guidelines and patient-reported measures of quality. The measures that relied on patient reports of problems with care, rather than patient ratings of satisfaction with care, seemed to be more responsive to change. These results support the value of benchmarking and collaboration.

Plain abdominal radiography in clinically suspected appendicitis: diagnostic yield, resource use, and comparison with CT.

This study determined the diagnostic utility and hospital resource impact of plain abdominal radiography in emergency department patients with suspected appendicitis. The authors reviewed medical records of 821 consecutive patients hospitalized for suspected appendicitis; 78% had plain abdominal radiography. Sixty-four percent had appendicitis. Radiographic findings were noted in 51% of patients with, and 47% of patients without appendicitis; no individual radiographic finding was sensitive or specific. Specific conditions were suggested in 10% of impressions; these failed to correlate with final clinical diagnoses 57% of the time. Hospital cost per abdominal radiograph was $67; cost per specific, correct radiographic diagnosis was $1,593. This is compared with $270 per appendiceal computed tomography scan (based on recent literature data). The authors conclude that plain abdominal radiographs in patients with suspected appendicitis are neither sensitive nor specific, are frequently misleading, are costly per specific and correct diagnosis, and should not be routinely obtained on patients with suspected appendicitis.

Demonstration of high-fidelity simulation team training for emergency medicine.

Emergency medicine (EM) presents many cognitive, social, and systems challenges to practitioners. Coordination and communication under stress between and among individuals and teams representing a number of disciplines are critical for optimal care of the patient. The specialty is characterized by uncertainty, complexity, rapidly shifting priorities, a dependence on teamwork, and elements common to other risky domains such as perioperative medicine and aviation. High-fidelity simulators have had a long tradition in aviation, and in the past few years have begun to have a significant impact in anesthesiology. A national, multicenter research program to document the costs of teamwork failures in EM and provide a remedy in the form of an Emergency Team Coordination Course has developed to the point that high-fidelity medical simulators will be added to the hands-on training portion of the course. This paper describes an evolving collaborative effort by members of the Center for Medical Simulation, the Harvard Emergency Medicine Division, and the MedTeams program to design, demonstrate, and refine a high-fidelity EM simulation course to improve EM clinician performance, increase patient safety, and decrease liability. The main objectives of the paper are: 1) to present detailed specifications of tools and techniques for high-fidelity medical simulation; 2) to share the results of a proof-of-concept EM simulation workshop introducing multiple mannequin/ three-patient scenarios; and 3) to focus on teamwork applications. The authors hope to engage the EM community in a wide-ranging discussion and handson exploration of these methods.

EMS Agenda for the Future: where we are...where we want to be.

During the past 30 years, emergency medical services (EMS) in the United States have experienced explosive growth. The American health care system is now transforming, providing an opportune time to examine what we have learned over the past three decades in order to create a vision for the future of EMS. Over the course of several months, a multidisciplinary steering committee collaborated with hundreds of EMS-interested individuals, organizations, and agencies to develop the EMS Agenda for the Future. Fourteen EMS attributes were identified as requiring continued development in order to realize the vision established within the Agenda. They are integration of health services, EMS research, legislation and regulation, system finance, human resources, medical direction, education systems, public education, prevention, public access, communication systems, clinical care, information systems, and evaluation. Discussion of these attributes provides important guidance for achieving a vision for the future of EMS that emphasizes its critical role in American health care.

The effect of supervision of residents on quality of care in five university-affiliated emergency departments.

PURPOSE: To assess the impact of direct supervision of resident physicians by attending physicians on quality of care in emergency departments. METHOD: In 1993, compliance with process-of-care guidelines was measured for 3,667 patients cared for by residents in five emergency departments in Boston and Cambridge, Massachusetts. Those patients presented with abdominal pain, asthma/COPD, chest pain, hand laceration, head trauma, or vaginal bleeding. A follow-up survey to assess patient satisfaction and reported problems with care was completed by 1,094 randomly sampled patients. RESULTS: In multivariate analysis, residents directly supervised by attending physicians had significantly (p < .0001) higher adjusted mean percentage compliance with guidelines (64%) than did residents alone (55%). Better compliance was also associated with higher level of training of the resident and greater patient urgency. There was no significant difference between supervised and unsupervised residents in either adjusted patient satisfaction or reported problems with care. CONCLUSIONS: Direct supervision of residents in emergency departments is significantly associated with better compliance with guidelines, regardless of level of training. However, direct supervision was not shown to influence patients' experience with care.

Two regions of simian virus 40 large T-antigen independently extend the life span of primary C57BL/6 mouse embryo fibroblasts and cooperate in immortalization.

Expression of the SV40 large T-antigen allows primary cells to escape senescence and thereby become immortalized. Immortalization occurs in two steps, extension of life span and acquisition of unlimited cell division potential. By following the increase in expression of a senescence-associated marker with increased cell passage, we show that C57Bl/6 mouse embryo fibroblast (B6MEF) cultures senesce by passage 4. Thus, the development of colonies from cultures transfected with T-antigen expressing constructs indicates extension of life span. Two T-antigen regions independently extended the life span of B6MEF. Expression of either a T-antigen consisting of amino acids 1-147 (T1-147) or a T-antigen consisting of amino acids 251-708 (T251-708) resulted in colony development. However, the colonies expressing these truncated T-antigens could not be expanded into cell lines efficiently. In contrast, coexpression of T1-147 and T251-708 produced colonies that could be expanded into cell lines as efficiently as could colonies expressing full-length T-antigen. Thus, the two regions of T-antigen contain analogous activities that are sufficient to extend cell life span; they cooperate to immortalize primary B6MEF; and they act in trans, indicating that the functions involved are independent.

EMS agenda for the future: where we are ... where we want to be. EMS Agenda for the Future Steering Committee.

During the past 30 years, emergency medical services (EMS) in the United States have experienced explosive growth. The American health care system is now transforming, providing an opportune time to examine what we have learned over the past three decades in order to create a vision for the future of EMS. Over the course of several months, a multidisciplinary steering committee collaborated with hundreds of EMS-interested individuals, organizations, and agencies to develop the "EMS Agenda for the Future." Fourteen EMS attributes were identified as requiring continued development in order to realize the vision established within the Agenda. They are Integration of Health Services, EMS Research, Legislation and Regulation, System Finance, Human Resources, Medical Direction, Education Systems, Public Education, Prevention, Public Access, Communication Systems, Clinical Care, Information Systems, and Evaluation. Discussion of these attributes provides important guidance for achieving a vision for the future of EMS that emphasizes its critical role in American health care.

Prospective study of blunt aortic injury: Multicenter Trial of the American Association for the Surgery of Trauma.

BACKGROUND: Blunt aortic injury is a major cause of death from blunt trauma. Evolution of diagnostic techniques and methods of operative repair have altered the management and posed new questions in recent years. METHODS: This study was a prospectively conducted multi-center trial involving 50 trauma centers in North America under the direction of the Multi-institutional Trial Committee of the American Association for the Surgery of Trauma. RESULTS: There were 274 blunt aortic injury cases studied over 2.5 years, of which 81% were caused by automobile crashes. Chest computed tomography and transesophageal echocardiography were applied in 88 and 30 cases, respectively, and were 75 and 80% diagnostic, respectively. Two hundred seven stable patients underwent planned thoracotomy and repair. Clamp and sew technique was used in 73 (35%) and bypass techniques in 134 (65%). Overall mortality was 31%, with 63% of deaths being attributable to aortic rupture; mortality was not affected by method of repair. Paraplegia occurred postoperatively in 8.7%. Logistic regression analysis demonstrated clamp and sew (p = 0.002) and aortic cross clamp time of > or = 30 minutes (p = 0.01) to be associated with development of postoperative paraplegia. CONCLUSIONS: Rupture after hospital admission remains a major problem. Although newer diagnostic techniques are being applied, at this time aortography remains the diagnostic standard. Aortic cross clamp time beyond 30 minutes was associated with paraplegia; bypass techniques, which provide distal aortic perfusion, produced significantly lower paraplegia rates than the clamp and sew approach.

A canine study of cold water drowning in fresh versus salt water.

OBJECTIVE: To compare the pathophysiologic changes occurring during drowning in cold fresh water and cold salt water with reference to viability. DESIGN: Randomized, prospective, controlled submersion experiments in two contrasting cold liquids. SETTING: A laboratory at a large university-affiliated medical institution. SUBJECTS: Thirteen healthy, anesthetized mongrel dogs. Three dogs served as controls and were immersed but not submerged. The remainder were submerged in cold fresh water or cold salt water (4 degrees C). INTERVENTIONS: Catheters were placed in the femoral artery, right carotid artery and right internal jugular vein. Electrocardiogram, pneumogram, and rectal temperatures were measured continuously during submersion/immersion. MEASUREMENTS AND MAIN RESULTS: Cold water submersion with drowning produced a large initial decrease in carotid artery temperature (approximately 7.5 degrees C in the first 2 mins) compared with a minor decrease (approximately 0.8 degrees C with immersion). No significant differences were noted in the rate of decrease of temperature between drowning in fresh water and salt water. During cold fresh water drowning, aspiration produced gross hemodilution with an average increase in body weight of 16.5%. Hematocrit values, serum sodium concentrations, and osmolality decreased while serum potassium concentrations, catecholamines, and free hemoglobin increased. All measured biochemical data (except PaO2) remained at viable levels. By contrast, during cold salt water drowning, average body weight increased by only 6%, with hemoconcentration and a shrinkage of vascular volume. Hematocrit and hemoglobin values increased by 30%, but initial plasma free hemoglobin values remained unchanged. Serum sodium concentrations, osmolality, and potassium concentrations increased rapidly to critical levels. CONCLUSIONS: On submersion in cold water, all of the experimental animals developed tachypnea immediately, followed by aspiration with predictable effects. The biochemical and pathophysiologic changes in cold water drowning approximated those changes reported for warm water drowning for both fresh and salt water with one exception and continued aspiration of cold water produced extremely rapid core cooling as long as the circulation remained intact. This process of acute submersion hypothermia may protect the brain temporarily from lethal damage, as reported in cases of cold fresh water drowning. Concentrations of circulating catecholamines increased exponentially in both groups of test animals. Clinically, their acute effects on the circulation, compounded by significant hypothermia and extreme anoxia, must hamper the detection of residual circulation at rescue and may play a role in sudden death from cold water in the absence of drowning.

Effect of oral digoxin, topical ouabain and salbutamol on transepithelial nasal potential difference in patients with cystic fibrosis.

1. Airway epithelium in cystic fibrosis is characterized by a defect in chloride secretion across the apical membrane and an increase in sodium absorption. The increased rate of sodium absorption can be inhibited in vitro by ouabain, a Na(+)-K(+)-ATPase inhibitor, and in cystic fibrosis patients the number and activity of nasal epithelial Na(+)-K(+)-ATPase pumps is increased. 2. We have performed a series of studies to determine whether drugs which modify airway epithelial Na(+)-K(+)-ATPase activity in vitro can modify nasal potential in cystic fibrosis patients in vivo. As transepithelial nasal potential difference measurements were used to study the effect of drug modulation of airway epithelial ion transport in vivo, the repeatability of the technique was first evaluated. In order to assess the effectiveness of the technique used for measuring nasal potential difference, a pilot study was carried out using topical amiloride, a drug which has previously been shown to inhibit airway epithelium sodium transport in vivo. We then studied the effects of ouabain and digoxin, two inhibitors of Na(+)-K(+)-ATPase, on nasal potential difference. 3. In study 1, nasal potential difference measurements were repeated on non-consecutive days in 20 patients with cystic fibrosis and 20 healthy individuals. Healthy subjects had a mean (SEM) potential difference value of -19.5 (0.9) mV with a 95% range for a single estimate of 75-133%. In patients with cystic fibrosis, the mean (SEM) potential difference was -40.4, (2.1) mV, with a 95% range for a single estimate of 74-136%.(ABSTRACT TRUNCATED AT 250 WORDS)

Simian virus 40 large T antigen contains two independent activities that cooperate with a ras oncogene to transform rat embryo fibroblasts.

The simian virus 40 large T antigen immortalizes growing primary cells in culture. In addition, this viral oncoprotein cooperates with an activated ras protein to produce dense foci on monolayers of rat embryo fibroblasts (REF). The relationship between independent immortalization and cooperative transformation with ras has not been defined. Previously, two regions of T antigen were shown to contain immortalization activities. An N-terminal fragment consisting of amino acids 1 to 147 immortalizes rodent cells (L. Sompayrac and K. J. Danna, Virology 181:412-415, 1991). Loss-of-function analysis indicated that immortalization depended on integrity of the T-antigen segments containing amino acids 351 to 450 and 533 to 626 (T. D. Kierstead and M. J. Tevethia, J. Virol. 67:1817-1829, 1993). The experiments described here were directed toward determining whether these same T-antigen regions were sufficient for cooperation with ras. Initially, constructs that produce T antigens containing amino acids 176 to 708 (T176-708) or 1 to 147 were tested in a ras cooperation assay. Both polypeptides cooperated with ras to produce dense foci on monolayers of primary REF. These results showed that T antigen contains two separate ras cooperation activities. In order to determine the N-terminal limit of the ras cooperation activity contained within the T176-708 polypeptide, a series of constructs designed to produce fusion proteins containing T-antigen segments beginning at residues 251, 301, 337, 351, 371, 401, 451, 501, 551, 601, and 651 was generated. Each of these constructs was tested for the capacity to cooperate with ras to produce dense foci on REF monolayers. The results indicated that a polypeptide containing T-antigen amino acids 251 to 708 (T251-708) was sufficient to cooperate with ras, whereas the more extensively truncated products were not. The abilities of the N-terminally truncated T antigens to bind p53 were examined in p53-deficient cells infected with a recombinant vaccinia virus expressing a phenotypically wild-type mouse p53. The results showed that polypeptides containing T-antigen amino acids 251 to 708, 301 to 708, 337 to 708, or 351 to 708 retained p53-binding capacity. The introduction into the T251-708 polypeptide of deletions that either prevented p53 binding (dl434-444) or did not prevent p53 binding (dl400) abrogated ras cooperation. These results indicated that although p53 binding may be necessary for ras cooperation, an additional, as-yet-undefined activity contained within the T251-708 polypeptide is needed.