Biomedical subjects

A Bagley

Publications and source records attributed to A Bagley.

8 recordsLinked to original sources

PubMed2001

Prosthetic arm monitoring system using a programmable interface controller.

Children with upper extremity limb deficiency are often prescribed a prosthetic arm to assist with daily function. Three types of prostheses are available: passive, active body-powered, and active myoelectric; costs range from $3,000 to $15,000. Clinicians rely on parent and child feedback regarding the usefulness of the prosthesis, and may assess the child's skill in using the device in a controlled setting. However, these methods do not provide an objective quantification of the wear and use of the device during daily activities. The purpose of this project is to develop a sensor to record the amount of time per day the prosthetic arm is worn, and to count the number of times per day the child activates (closes) the prosthetic hand (or terminal device). The system that has been developed can be integrated unobtrusively into a child's prosthetic arm. A programmable interface controller (PIC) with interface circuitry and memory was developed to record the daily wear pattern and hand usage of the prosthesis at 15-minute intervals. Memory and battery capacities are sufficient to record data over a three-month period. A personal computer interface downloads the collected data and may be used to reprogram the device for different time periods of data collection. All components, including the battery, have a mass of 87 grams and fit inside the forearm cavity of a 9-year old's prosthesis. Controlled trials are underway at Shriners Hospital for Children, Northern California, to determine system reliability.

Arm↗

PubMed2000

A biomechanical analysis of gait during pregnancy.

BACKGROUND: There are many anatomical changes during pregnancy that could potentially lead to substantial alterations in gait. Gait deviations may contribute to a variety of musculoskeletal overuse conditions associated with pregnancy, such as low-back, hip, and calf pain. Because we are aware of little research on this topic, the purpose of this study was to objectively analyze gait during pregnancy. METHODS: Three-dimensional gait analysis was performed on fifteen women during the second half of the last trimester of pregnancy and again one year post partum. Selected kinematic and kinetic parameters for the pregnancy and one-year postpartum conditions were compared with use of paired t tests (95 percent significance level). RESULTS: Overall, gait kinematics were remarkably unchanged during pregnancy. No evidence of a so-called waddling gait during pregnancy was found. Maximum anterior pelvic tilt during gait increased a mean of 4 degrees during pregnancy, although individual subject-to-subject variation (range, an increase of 13 degrees to a decrease of 10 degrees) was observed. Significant increases in hip and ankle kinetic gait parameters, however, were observed during pregnancy (p < 0.05). CONCLUSIONS: Significant increases in kinetic gait parameters during pregnancy (p < 0.05) explain how gait motion remained relatively unchanged despite increases in body mass and width as well as changes in mass distribution about the trunk. This finding indicates that during pregnancy there may be an increased demand placed on hip abductor, hip extensor, and ankle plantar flexor muscles during walking.

Adult↗

PubMed1994

Major findings from the clinical trials of the intravascular oxygenator.

Major clinically relevant findings have been extracted and summarized from the database developed from the international multicenter clinical trials of the intravascular oxygenator (IVOX) as a means for augmenting the deficient blood gas transfer of patients in advanced acute respiratory failure (ARF). Between February 1990 and May 1993, a total of 164 IVOX devices were utilized in 160 clinical trial patients who were hypoxemic and/or hypercarbic while receiving closed system positive pressure mechanical ventilator support at or exceeding generally accepted minimum safe levels of intensity. The average rates of oxygen and carbon dioxide transfer into and out of circulating venous blood by means of the IVOX device varied from 40-70 ml/min. Evidence of patient benefit during IVOX utilization includes improvement in blood gas partial pressures associated with decreased intensity of mechanical ventilation, improved hemodynamics in patients with mechanical ventilator depressed cardiovascular function, and decreased indices of lung dysfunction. Clinically recognized IVOX-related complications or adverse events were reported in 24.5% of the clinical trials patients. At necropsy examination of 68 clinical trials patients who died during or after IVOX utilization, forensic pathologists reported 4 cases in which IVOX utilization could have been a primary or contributing cause of death. Significant IVOX device mechanical and/or performance malfunction problems were recognized in 29 (17.7%) of the IVOX devices utilized in clinical trials. IVOX clinical trials data collected and analyzed to date indicate IVOX utilization has a favorable risk/benefit ratio in patients in severe, acute, potentially reversible ARF.

Acute Disease↗

PubMed1985

Acquisition of cytomegaloviral infections in families with young children: a serological study.

Acquisition of cytomegalovirus (CMV) infection in families with young children was investigated with serial serological tests for antibody to CMV by using ELISA and anti-complement immunoflourescence. Members of 68 Houston families were studied for a mean of 3.5 years. Seroconversion occurred in one or more members of 37 (53%) of 68 families studied. The mean annual seroconversion rate was 10% for fathers, 10.6% for mothers, and 10.3% for children. The attack rate for susceptible family members (including the index case) was 54%. The index case was the child in 10 instances, the father in 2, and the mother in 2. The index case could not be identified in 23 families. This Houston study indicates that the family with young children is a high-risk setting for CMV infection. This is an important concern regarding risks for mothers in their childbearing and child-rearing years.

Adolescent↗

PubMedDate not supplied

Objective assessment of dyskinesia in children with cerebral palsy.

The clinical classification of children with cerebral palsy is limited by multiple factors. Distinguishing between spasticity and dyskinesia is critical, because the outcome after standard orthopaedic and neurosurgical interventions is less predictable in children with cerebral palsy who have a significant dyskinetic component. This study applied computer-based analysis of gait to assess objectively the presence of significant dyskinesia in children with cerebral palsy. Three-dimensional gait analysis was performed on 18 normal children, 17 children with principally spastic cerebral palsy, and 23 children with significantly dyskinetic cerebral palsy. Children were assigned to the spastic or dyskinetic groups prospectively, based on clinical analysis by an experienced physician and physical therapist. The children with dyskinesia were found to have a significantly wider, and more variable normalized dynamic base of support, a smaller step profile (step length divided by step width), and a greater and more variable maximal lateral acceleration than the spastic and normal groups (mixed model analysis of variance, p = 0.0001). A predictive model of dyskinesia, (developed by logistic regression analysis), using these gait parameters, exhibited excellent sensitivity, correctly classifying 20 (87%) of 23 children as dyskinetic. This study shows that children with dyskinetic cerebral palsy have distinct gait parameters and that objective assessment of dyskinesia in children with cerebral palsy is possible with computer-based analysis of gait.

Adolescent↗

PubMedDate not supplied

Voluntary (normal) versus obligatory (cerebral palsy) toe-walking in children: a kinematic, kinetic, and electromyographic analysis.

Surgical management of toe-walking gait in children with cerebral palsy currently favors simultaneous, multilevel soft-tissue and bony interventions. Formulation of such a surgical plan is based on our ability to determine which of the gait deviations present are primary and which are secondary or compensatory. To evaluate this issue further, 32 normal children, walking normally and voluntarily toe-walking, were compared to 15 children with cerebral palsy walking in an obligatory toe-walking gait pattern. Computer-based analysis of gait was performed for each child, including time-distance, kinematic, kinetic, and electromyographic analyses. Significant deviations common to both normal and cerebral palsy toe-walking groups were determined to be due, at least in part, to the biomechanical constraints associated with a toe-walking gait pattern. Deviations unique to the cerebral palsy group were thought to represent primary gait deviations related to the underlying injury to the central nervous system. This study identifies the need to develop more sophisticated techniques of data collection and analysis and supports the inclusion of more varied and demanding functional activities for distinguishing between primary and secondary gait deviations in children with cerebral palsy.

Adolescent↗

PubMedDate not supplied

Quantitative gas transfer into and out of circulating venous blood by means of an intravenacaval oxygenator.

The volume of O2 and CO2 transferred into/out circulating venous blood by various sized IVOX devices has been assessed by ex vivo and in vivo animal experiments and by reviewing the gas transfer data collected from the first 20 human ARDS patients studied during Phase I of the IVOX clinical trials. Data from these assessments indicate that oxygen transfer through the size 5 IVOX ranges from 15.4 to 18.0 cc/min; through the size 6 IVOX ranges from 22.8 to 35.5 cc/min; through the size 7 IVOX ranges from 28.5 to 66.7 cc/min; through the size 8 IVOX ranges from 34.9 to 66.3 cc/min; through the size 9 IVOX ranges from 45.9 to 115.7 cc/min; through the size 10 IVOX ranges from 52.9 to 133 cc/min. Quantitative carbon dioxide transfer through the various size IVOX devices closely follows the quantitative oxygen transfer achieved by IVOX. These quantitative data provide valuable information to clinicians considering using IVOX to augment the inadequate gas transfer existing in patients with acute, potentially reversible respiratory failure. They indicate IVOX transfers clinically significant quantities of O2 into and CO2 out of circulating venous blood in an intact subject without involving the subjects natural lungs.

Animals↗

PubMedDate not supplied

In vitro comparison of filled and unfilled universal bonding agents of amalgam to dentin.

In this study, four different adhesive amalgam systems were compared(Amalgambond Plus, Amalgambond Plus with HPA, All-Bond 2, and All-Bond 2 with Liner-F) regarding their ability to bond amalgam to freshly prepared dentinal surfaces. The two groups that yielded the highest mean bond strengths, Amalgambond Plus with HPA and All-Bond 2 with Liner-F, were the only two groups in comparison that were not statistically different (P > 0.05). The use of the filled resin bonding agents created significantly higher bond strengths between tooth and freshly triturated amalgam than the unfilled resin bonding agents. Further study is required to determine: a) the exact nature and mechanism of the bonds, and b) clinical in vivo presence and longevity of the bonds.

Analysis of Variance↗