Designing informed game-based rehabilitation tasks leveraging advances in virtual reality

PURPOSE

This paper details a brief history and rationale for the use of virtual reality (VR) technology for clinical research and intervention, and then focuses on game-based VR applications in the area of rehabilitation. An analysis of the match between rehabilitation task requirements and the assets available with VR technology is presented.

KEY MESSAGES AND IMPLICATIONS

Low-cost camera-based systems capable of tracking user behavior at sufficient levels for game-based virtual rehabilitation activities are currently available for in-home use. Authoring software is now being developed that aims to provide clinicians with a usable toolkit for leveraging this technology. This will facilitate informed professional input on software design, development and application to ensure safe and effective use in the rehabilitation context.

CONCLUSION

The field of rehabilitation generally stands to benefit from the continual advances in VR technology, concomitant system cost reductions and an expanding clinical research literature and knowledge base. Home-based activity within VR systems that are low-cost, easy to deploy and maintain, and meet the requirements for "good" interactive rehabilitation tasks could radically improve users' access to care, adherence to prescribed training and subsequently enhance functional activity in everyday life in clinical populations.

A randomized controlled trial of the psychosocial impact of providing internet training and access to older adults

The Internet (electronic mail and the World Wide Web) may provide new opportunities for communication that can help older adults avoid social isolation. This randomized controlled trial assessed the psychosocial impact of providing Internet access to older adults over a five-month period. One hundred volunteers from four congregate housing sites and two nursing facilities were randomly assigned to receive Internet training or to a wait list control group. The pre & post measures included the UCLA Loneliness scale, modified CES Depression scale, a measure of locus of control, computer attitudes, number of confidants, and overall quality of life. Participants received nine hours of small group training in six sessions over two weeks. Computers were available for continued use over five months and the trainer was available two hours/week for questions. At the end of the trial, 60% of the intervention group continued to use the Internet on a weekly basis. Although there was a trend toward decreased loneliness and depression in intervention subjects compared to controls, there were no statistically significant changes from baseline to the end of trial between groups. Among Internet users (n = 29) in the intervention group there were trends toward less loneliness, less depression, more positive attitudes toward computers, and more confidants than among intervention recipients who were not regular users (n = 19) of this technology. Most elderly participants in this trial learned to use the Internet and the majority continued to use it on a weekly basis. The psychosocial impact of Internet use in this sample suggested trends in a positive direction. Further research is needed to determine more precisely, which older adults, residing in which environmental contexts are more likely than others to benefit from this rapidly expanding information and communication link.

Pain in nursing home residents: an exploration of prevalence, staff perspectives, and practical aspects of measurement

OBJECTIVE

To help rectify the underdiagnosis of chronic pain in frail nursing home residents by developing a new feasible pain self-report instrument, the structured pain interview; to use this new tool to estimate pain prevalence and staff's knowledge of residents' pain in two nursing homes; and to compare the performance differences of the structured pain interview and the commonly used 0-10 scale.

DESIGN

Cross-sectional survey.

SETTING

One 120-bed VA-affiliated and one 125-bed university-affiliated, community-based nursing home in Durham, North Carolina.

PATIENTS

One hundred fifty-eight chronic care nursing home residents without aphasia, acute illness, persistent vegetative status, or severe hearing impairment and 3 1 nursing home nurses.

OUTCOME MEASURES

Pain prevalence according to resident self-report and nurse report; stability of response to the structured pain interview and 0-10 scale over 1 month; agreement between residents and nurses on the structured pain interview and 0-10 scale.

RESULTS

Fifty-eight percent of the VA and 45% of the community nursing home residents reported pain. Forty-two percent at the VA and 20% at the community home were unable to respond to the 0-10 scale, compared with 7.5% and 14% using the structured pain interview. Stability of response to the structured pain interview at 1 month was 0.56 at the VA (nurse-resident agreement 0.38) and 0.72 in the community (nurse-resident agreement 0.07), which was very comparable to the 0-10 scale.

CONCLUSIONS

We have developed a highly feasible tool for examining pain prevalence in nursing homes. This tool uncovered considerable miscommunication regarding pain between residents and staff. Improvement in pain communication between nursing home residents and staff is needed, so that more effective pain treatment programs can be developed for this vulnerable population.

Screening methods for thyroid hormone disruptors

The U.S. Congress has passed legislation requiring the EPA to implement screening tests for identifying endocrine-disrupting chemicals. A series of workshops was sponsored by the EPA, the Chemical Manufacturers Association, and the World Wildlife Fund; one workshop focused on screens for chemicals that alter thyroid hormone function and homeostasis. Participants at this meeting identified and examined methods to detect alterations in thyroid hormone synthesis, transport, and catabolism. In addition, some methods to detect chemicals that bind to the thyroid hormone receptors acting as either agonists or antagonists were also identified. Screening methods used in mammals as well as other vertebrate classes were examined. There was a general consensus that all known chemicals which interfere with thyroid hormone function and homeostasis act by either inhibiting synthesis, altering serum transport proteins, or by increasing catabolism of thyroid hormones. There are no direct data to support the assertion that certain environmental chemicals bind and activate the thyroid hormone receptors; further research is indicated. In light of this, screening methods should reflect known mechanisms of action. Most methods examined, albeit useful for mechanistic studies, were thought to be too specific and therefore would not be applicable for broad-based screening. Determination of serum thyroid hormone concentrations following chemical exposure in rodents was thought to be a reasonable initial screen. Concurrent histologic evaluation of the thyroid would strengthen this screen. Similar methods in teleosts may be useful as screens, but would require indicators of tissue production of thyroid hormones. The use of tadpole metamorphosis as a screen may also be useful; however, this method requires validation and standardization prior to use as a broad-based screen.

Pain measurement in elders with chronic low back pain: traditional and alternative approaches

Pain evaluation typically relies upon the use of self-report instruments. The validity of these tools is questionable in many older adults, however, particularly those with cognitive impairment. Rating of pain behavior (e.g. grimacing, sighing) by an objective observer represents an alternative pain assessment strategy which has been validated in subjects of heterogeneous ages. The purpose of this study was to examine, in a group of community-dwelling elderly with low back pain and lumbosacral osteoarthritis, the concurrent validity of observational pain behavior rating techniques as compared with self-report instruments and the degree to which pain and pain behavior relate to disability. Thirty-nine cognitively intact subjects, age > 65 years, without depression, other sources of pain, or other known spinal pathology underwent the following measures: (1) pain self-report using the verbal 0-10 scale, vertical verbal descriptor scale, Arthritis Impact Measurement Scales and McGill Pain Questionnaire; (2) pain behavior was sampled during two protocols, one, identical to that used by Keefe and Block (Behav. Ther., 13 (1982) 363-375), that required subjects to sit, stand, walk, and recline for 1-2 minute periods (which we have labelled the traditional protocol), and a second, more demanding protocol that was designed to simulate activities of daily living that place a premium on axial movement (the 'ADL' protocol); (3) disability was assessed using the Roland questionnaire, a 6 month global disability question and the Jette Functional Status Index; and (4) radiographic evaluation of the lumbosacral spine; osteoarthritis was quantitated using a previously validated scoring system. Interrelationships among pain, pain behavior and disability measures were tested using canonical correlations. Self-reported pain was associated with pain behavior frequency; the association was stronger when the ADL protocol was used, as compared with the traditional protocol. The association between pain and disability was modestly strong with both self-report instruments and pain behavior observation when the ADL protocol was used, but not when the traditional protocol was used. Our findings suggest that pain behavior observation is a valid assessment tool in the elderly. In addition, it seems that observation of elders during performance of activities of daily living may be a more sensitive and valid way of assessing pain behavior than observing pain behavior during sitting, walking, standing, or reclining.

The reliability, validity, and stability of a measure of physical activity in the elderly

OBJECTIVE

To assess the reliability, validity, and stability of an accelerometer-based monitor of physical activity in an elderly population.

DESIGN

Six studies were conducted to assess the Tritrac, a newly available accelerometer capable of storing three-dimensional activity data collected in minute epochs. After initial bench testing, the waist-worn devices were assessed for test-retest reliability during sitting and treadmill walking at 1mph and 2mph. Validity testing examined the Tritrac's ability to discriminate between different levels of physical activity and also compared the Tritrac with an established wrist-worn acclerometer, the Actigraph. Stability of the measure was examined over a period of 3 to 7 days, and in a subset of subjects this measurement was performed for a second week.

SETTING AND SUBJECTS

Residents of a VA Nursing Home (n = 40; mean age = 76), participants in an in-home nonaerobic exercise program (n = 36; mean age = 77), and community participants in an aerobic exercise program (n = 10; mean age = 71).

RESULTS

Intraclass correlation coefficients (ICC) for both the bench testing and test-retest reliability were .97. The device discriminated among subjects independently categorized as sedentary, moderately active, or active (F = 49.4, p = .0001) and between specific activities of varying intensity (F = 114.5, p = .0001). Tritrac and Actigraph measurement comparison showed a correlation of r = .77, p = .0001. Stability of the measure was demonstrated by ICCs = .81 and .78 for mean activity values and proportion of time spent in sedentary activity, respectively. No significant differences were observed when comparing activity measured for two separate weeks.

CONCLUSION

The Tritrac is a reliable and valid instrument producing activity measurement that was stable over time in the elderly population we studied. During our longitudinal testing, 20% of the subjects did not comply with wearing the device; this noncompliance issue must be considered in any use of the Tritrac.

Weight of the evidence on the human carcinogenicity of 2,4-D

The phenoxy herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is widely used to control the growth of weeds and broadleaf plants. We convened a panel of 13 scientists to weigh the evidence on the human carcinogenicity of 2,4-D. The panel based its findings on a review of the toxicological and epidemiological literature on 2,4-D and related phenoxy herbicides. The toxicological data do not provide a strong basis for predicting that 2,4-D is a human carcinogen. Although a cause-effect relationship is far from being established, the epidemiological evidence for an association between exposure to 2,4-D and non-Hodgkin's lymphoma is suggestive and requires further investigation. There is little evidence of an association between use of 2,4-D and soft-tissue sarcoma or Hodgkin's disease, and no evidence of an association between 2,4-D use and any other form of cancer. Scientists on the panel were asked to categorize 2,4-D as a "known," "probable," "possible," or "unlikely" carcinogen or as a noncarcinogen in humans. The predominant opinion among the panel members was that the weight of the evidence indicates that it is possible that exposure to 2,4-D can cause cancer in humans, although not all of the panelists believed the possibility was equally likely: one thought the possibility was strong, leaning toward probable, and five thought the possibility was remote, leaning toward unlikely. Two panelists believed it unlikely that 2,4-D can cause cancer in humans.

Effect of 60Co-irradiation on the development and immunogenicity of Plasmodium berghei sporozoites in Anopheles stephensi mosquitoes

Protection conferred to mice by Plasmodium berghei sporozoites increased significantly when the time interval between 60Co-irradiation of the infected mosquitoes and harvest of sporozoites increased. One thousand sporozoites conferred no protection against challenge if harvested on the day of irradiation, but protected 60% of recipient mice when harvested 28 days postirradiation. When the time between feeding of mosquitoes and irradiation was varied, sporozoites from mosquitoes irradiated 3 days after feeding were infective for mice. Sporozoites from mosquitoes irradiated on day 10 postfeeding were not infective, but were immunogenic. In all experiments a decline occurred in the number of recoverable sporozoites over a 28-day period postirradiation to less than 10% of the yield on the day of irradiation.

Duration of immunity following a single vaccination with irradiated sporozoites of Plasmodium berghei

A rodent model of sporozoite immunization against malaria based on a single immunizing dose is described. The duration of protective immunity was measured as a function of dose, and the results suggest that the percentage of protection follows a bimodal distribution. The first peak occurs between days 7-12 after immunization, while the second peak occurs at approximately 28 days. Although the percentage of protection declines steadily after the second peak, some immunity was detectable as long as 140 days after immunization with the higher doses.

The use of membrane screen filters in the isolation of Plasmodium berghei sporozoites from mosquitos

An improved procedure is presented for the isolation of Plasmodium berghei sporozoites from host mosquitos. The method employs filtration through a series of Nuclepore membranes followed by two consecutive centrifugations of the filtrate layered over Renografin-60 solutions of different densities. A Coulter Counter was used to compare isolations prepared by this technique with those prepared by a routinely employed discontinuous gradient method. When the sporozoite concentration in each preparation was standardized at 300 sporozoites per ml, isolations prepared by the new technique were significantly cleaner than isolations prepared by the discontinuous gradient method, containing an average of 1706 total particles per ml compared with 46 107 total particles per ml. The latter procedure was more effective, however, in removing viable microorganisms. Sporozoites isolated by both techniques were similar in immunogenicity and virulence.

Bancroftian filariasis and membrane filters: are night surveys necessary?

Paired day and night blood specimens from 41 persons living in a hyperendemic Wuchereria bancrofti area of southwestern Ethiopia were examined for microfilariae by Nuclepore filter, thick film, and counting chamber techniques. Filtering techniques were so highly sensitive that more infected persons were identified by filtering day blood than by examining night blood by conventional methods. Increasing the volume of blood filtered from 1 ml to 5 ml increased the number of positives identified during the day. Filtering 5 ml of day blood obviated the need for examining night blood, even though a high proportion of infected persons had very low numbers of circulating microfilariae.

The use of penicillamine as an adjuvant to tartar emetic in the treatment of experimental schistosomiasis

One of the principal drawbacks of antimonial therapy in schistosomiasis has been the prevalence of annoying, and sometimes dangerous, side-effects. The adjuvant administration of chelating agents offers a possible solution to this problem, providing this can be achieved without appreciably decreasing the therapeutic effect of the drug.The authors found that the chelating agent penicillamine lowered the toxicity of tartar emetic for mice and hamsters without affecting the tissue uptake of antimony. When administered in a similar manner to hamsters infected with Schistosoma mansoni there was no effect on the uptake of antimony by the parasites, or on the cure rate. This suggests a potential usefulness of penicillamine in antimony therapy.