Use cases and usability challenges for head-mounted displays in healthcare

In the healthcare domain, head-mounted displays (HMDs) with augmented reality (AR) modalities have been reconsidered for application as a result of commercially available products and the needs for using computers in mobile context. Within a user-centered design approach, interviews were conducted with physicians, nursing staff and members of emergency medical services. Additionally practitioners were involved in evaluating two different head-mounted displays. Based on these measures, use cases and usability considerations according to interaction design and information visualization were derived and are described in this contribution.

Direct measurement of the spin Hamiltonian and observation of condensation of magnons in the 2D frustrated quantum magnet Cs2CuCl4

We propose a method for measuring spin Hamiltonians and apply it to the spin- 1/2 Heisenberg antiferromagnet Cs2CuCl4, which shows a 2D fractionalized resonating valence bond state at low fields. By applying strong fields we fully align the spin moment of Cs2CuCl4, transforming it into an effective ferromagnet. In this phase the excitations are conventional magnons and their dispersion relation measured using neutron scattering give the exchange couplings directly, which are found to form an anisotropic triangular lattice with small Dzyaloshinskii-Moriya terms. Using the field to control the excitations we observe Bose condensation of magnons into an ordered ground state.

Factors associated with tobacco sales to minors: lessons learned from the FDA compliance checks

CONTEXT

Tobacco products continue to be widely accessible to minors. Between 1997 and 1999, the US Food and Drug Administration (FDA) conducted more than 150,000 tobacco sales age-restriction compliance checks. Data obtained from these checks provide important guidance for curbing illegal sales.

OBJECTIVE

To determine which elements of the compliance checks were most highly associated with illegal sales and thereby inform best practices for conducting efficient compliance check programs.

DESIGN AND SETTING

Cross-sectional analysis of FDA compliance checks in 110,062 unique establishments in 36 US states and the District of Columbia.

MAIN OUTCOME MEASURE

Illegal sales of tobacco to minors at compliance checks; association of illegal sales with variables such as age and sex of the minor.

RESULTS

The rate of illegal sales for all first compliance checks in unique stores was 26.6%. Clerk failure to request proof of age was strongly associated with illegal sales (uncorrected sales rate, 10.5% compared with 89.5% sales when proof was not requested; multivariate-adjusted odds ratio [OR], 0.03; 95% confidence interval [CI], 0.03-0.04). Other factors associated with increased illegal sales were employment of older minors to make the purchase attempt (adjusted ORs for 16- and 17-year-old minors compared with 15-year-olds were 1.52 [95% CI, 1.46-1.63] and 2.43 [95% CI, 2.31-2. 59], respectively), attempt to purchase smokeless tobacco (adjusted OR, 2.16 [95% CI, 1.90-2.45] vs cigarette purchase attempts), and performing checks at or after 5 PM (adjusted OR, 1.28 [95% CI, 1. 21-1.35] vs before 5 PM). Female sex of clerk and minor, Saturday checks, type of store (convenience store selling gas, gas station, drugstore, supermarket and general merchandise), and rural store locations also were associated with increased illegal sales.

CONCLUSIONS

This analysis found that a request for age verification strongly predicted compliance with the law. The results suggest several ways in which the process of compliance checks might be optimized. JAMA. 2000;284:729-734

Assessing community-wide outcomes of prevention marketing campaigns through telephone surveys

Researchers at Battelle Centers for Public Health Research and Evaluation (CPHRE) were contracted by the Centers for Disease and Prevention (CDC) to conduct a random sample survey to serve as one component of the evaluation of the Prevention Marketing Initiative (PMI) Local Site Demonstration Project, a community-based HIV prevention program for adolescents. Data were collected from 1,402 adolescents over a 23-month period. A five wave, cross-sectional design was used. A dual sampling strategy combined Random Digit Dialing (RDD) with Listed Household (LHH) samples.

Particular care was devoted to ensuring the rights of teenaged participants. Data were collected anonymously and concerns about confidentiality and privacy informed design and operational decisions. Response rate goals were achieved. Factors that may have contributed to the adequacy of the response rate include the use of advance letters and a toll-free phone line as well as sensitivity to the needs and concerns of the target population, the perceived legitimacy of CDC research and the perseverance of the interviewers.

Early and longitudinal evaluations of treated infants and children and untreated historical patients with congenital toxoplasmosis: the Chicago Collaborative Treatment Trial

Between December 1981 and May 1991, 44 infants and children with congenital toxoplasmosis were referred to our study group. A uniform approach to evaluation and therapy was developed and is described herein along with the clinical characteristics of these infants and children. In addition, case histories that illustrate especially important clinical features or previously undescribed findings are presented. Factors that contributed to the more severe disabilities included delayed diagnosis and initiation of therapy; prolonged, concomitant neonatal hypoxia and hypoglycemia; profound visual impairment; and prolonged, uncorrected increased intracranial pressure with hydrocephalus and compression of the brain. Years after therapy was discontinued, three children developed new retinal lesions (without loss of visual acuity when therapy for Toxoplasma gondii was initiated promptly), and three children experienced a new onset of afebrile seizures. Most remarkable were the normal developmental, neurological, and ophthalmologic findings at the early follow-up evaluations of many--but not all--of the treated children despite severe manifestations, such as substantial systemic disease, hydrocephalus, microcephalus, multiple intracranial calcifications, and extensive macular destruction detected at birth. These favorable outcomes contrast markedly with outcomes reported previously for children with congenital toxoplasmosis who were untreated or treated for only 1 month.

Hearing loss in children with Down syndrome

Conventional behavioral testing of hearing shows that children with Down syndrome have a high prevalence of hearing deficits. However, most young (< 3.5 years of age) children with Down syndrome are unable to cooperate in this type of testing. We evaluated auditory brain-stem responses of 47 unselected patients 2 months to 3 1/2 years of age. Thirty-four percent had normal hearing, 28% had unilateral loss, and 38% had bilateral loss. Type of loss was conductive in 19 ears, mixed in 14, and sensorineural in 16. Degree of loss was mild in 33 ears, moderate in 13, and severe to profound in 3. Language quotients and degree of hearing loss were compared and an association was not found. Because of the high prevalence of hearing loss in children with Down syndrome, we recommend evaluation of auditory brain-stem responses in the first 6 months of life.

Absence of sensorineural hearing loss in treated infants and children with congenital toxoplasmosis

Educationally significant hearing loss has been reported in 10% to 15% of children with congenital toxoplasmosis. As part of a pilot study to assess feasibility and safety of prolonged therapy for congenital toxoplasmosis, 30 congenitally infected infants and children were evaluated for auditory function. Serial testing, beginning within 2 months of birth, was performed. Availability of auditory brainstem response (ABR) testing made evaluation at an earlier age than previously possible. Six (20%) of the 30 infants had mild to moderate conductive type hearing loss associated with otitis media. No infant or child had sensorineural hearing loss. The better outcome we observed compared to previous reports of a 15% to 26% incidence of sensorineural hearing loss and 10% to 15% incidence of educationally significant, bilateral hearing impairment may be related to early initiation and/or prolonged institution of antimicrobial therapy. Continued followup to exclude progressive hearing impairment and study of larger numbers of children are needed to verify these preliminary findings.

Viewing the audiogram through a mathematical model

In an effort to better quantify audiometric results, audiograms were modeled with a hyperbolic tangent function of the form: t = a tanh [(f-c)/b] + d, where t = threshold and f = frequency. The parameters, a, b, c, and d, were determined for a specific audiogram via a least-squares nonlinear curve fitting technique. The parameters describe salient features of the audiogram. The point (c,d) is the midpoint of the sloping portion of the audiogram, while a and b describe the slope. Other features of the configuration can be described by combinations of the parameters. This approach quantifies the entire audiogram and allows simple correlations of routinely gathered clinical data. To demonstrate the application of the model, a small data set of 500 Hz ABR and behavioral thresholds recorded from 28 ears (23 subjects) was analyzed. The model showed that agreement between the thresholds varied with audiometric configuration.