Assessment of a noninvasive optical photoplethysmography imaging device with dynamic tissue phantom models

Noncontact photoplethysmography (PPG) has been studied as a method to provide low-cost, noninvasive, two-dimensional blood oxygenation measurements and medical imaging for a variety of near-surface pathologies. To evaluate this technology in a laboratory setting, dynamic tissue phantoms were developed with tunable parameters that mimic physiologic properties of the skin, including blood vessel volume change, pulse wave frequency, and tissue scattering and absorption. Tissue phantoms were generated using an elastic tubing to represent a blood vessel where the luminal volume could be modulated with a pulsatile fluid flow. The blood was mimicked with a scattering and absorbing motility standard, and the tissue with a gelatin-lipid emulsion hydrogel. A noncontact PPG imaging system was then evaluated using the phantoms. Noncontact PPG imaging accurately identified pulse frequency, and PPG signals from these phantoms suggest that the phantoms can be used to evaluate noncontact PPG imaging systems. Such information may be valuable to the development of future PPG imaging systems.

Adolescent occupational injuries and workplace risks: an analysis of Oregon workers' compensation data 1990-1997

PURPOSE

Injuries to adolescents from occupational activities has been recognized as a significant public health concern. The objective of this study was to quantify adolescent injury rates, analyze risk factors, and measure the severity of injuries sustained using Oregon workers' compensation data.

METHODS

From 1990-1997, a total of 8060 workers' compensation claims, submitted by claimants 16-19 years old, were accepted by Oregon and used in these analyses. Data from the Bureau of Labor Statistics were used to derive injury rates.

RESULTS

An overall estimated claim rate of 134.2 (95% confidence interval [CI] 124.9-143.6) per 10,000 adolescent workers was found, with males having over twice the rate of females. The total average annual claim cost was $3,168,457, representing $3145 per claim. The average total temporary disability period per claim was 22.3 days. Precision production workers had the highest claim rate of 296.2 (95% CI 178.9-413.4) and highest associated costs ($8266) for all occupations, whereas those in the farming/fishing/forestry occupation had the longest average periods of indemnification with 31.6 days. Day shift workers had the highest claim rates and most severe injuries relative to other shifts.

CONCLUSION

The injury rates found among adolescent workers demonstrates that continued safety interventions and increased training are needed. Because of high claim rate and injury severity, particular attention should be focused on adolescents in food service, manufacturing, and agricultural occupations. Understanding the differences of adolescent circadian rhythm patterns in establishing work schedules and supervisory practices could also prove valuable for decreasing injury risk.

An assessment and quantification of the rates, costs, and risk factors of occupational amputations: analysis of Kentucky workers' compensation claims, 1994-2003

BACKGROUND

Assessments of the impact of occupational amputations with outcomes of pain, disfigurement, and often an inability to return to the same job, are limited. The present study examines and quantifies the rates, risk factors, and costs of occupational amputations in the workplace in the State of Kentucky.

METHODS

Worker's compensation data from 1994 through 2003 from Kentucky was used to investigate job-related amputations (n = 2,297). The US Department of Labor's Current Population Survey (CPS) was used to estimate injury rates.

RESULTS

The average amputation claim rate for all Kentucky workers was 1.37 per 10,000, with an average per-claim indemnity cost of $8,822. A declining trend was found in the rate over the last 7 years studied. Accidents resulting in amputations occurred at twice the rate on weekends than on weekdays. Amputations affecting the hand constituted 94.6% of all injuries. Workers in the mining industry had the highest estimated claim rate of 5.92 (95% CI 5.23-6.66), and machine operators and assemblers had the highest rate of all occupations with 3.35 (95% CI 3.23-3.47).

CONCLUSIONS

Workplace amputations remain a significant workplace concern and represent a particular hazard for those in the mining and manufacturing industries. Future research should examine causes of the weekend effect to develop human resource and safety interventions for risk reduction.

Surveillance and assessment of workplace assault injuries: analysis of Rhode Island workers' compensation claims 1998-2002

OBJECTIVE

To analyze workplace assault by rate, injury severity, and trends using Rhode Island workers' compensation claim data.

METHOD

A total of 6402 workers' compensation assault claims from Rhode Island for the period of 1998 through 2002 was analyzed. Data from the U.S. Department of Labor was used to derive estimates of injury rates.

RESULTS

An average rate of 27.7 assaults per 10,000 workers was found and varied only marginally across years. Females filed 75% of all assault claims, though injuries to males resulted in longer periods of indemnification. The total cost of workplace assaults was 7,025,997 dollars, averaging 1097 dollars per claim, and average indemnification duration was 16.8 days per claim. While the assault rate was relatively stable, a notable decline in both cost and indemnification periods over time was discovered.

CONCLUSION

The assault rate found was among the highest reported to date, demonstrating that workplace violence remains a significant threat to employee safety. While a decline in incident severity was discovered over time, many outcomes were still serious. Preventive interventions to reduce incidents of workplace assaults among groups at the highest risk should be given highest priority.

An analysis of occupational burn injuries in Rhode Island: workers' compensation claims, 1998 to 2002

Occupational burns have been determined to be a serious public health concern. The analysis of workplace risks and risk factors associated with burns are critical to developing effective interventions in the future. In this study, we examined accepted Rhode Island workers' compensation claims (n = 5619) from 1998 to 2002 to assess the rates and risks of occupational burns. We used employment data from the Department of Labor's Current Population Survey (CPS) to estimate claim rates and shift analyses. The overall burn rate was estimated to be 24.3 per 10,000 workers. The claim rate for workers younger than 25 years of age was almost double that for all other age groups. The average per-claim disability duration for claims requiring indemnity was 167.9 days, and average annual total cost of claims was dollar 1,010,166. The highest claim rate identified was for workers in food service occupations and an increased risk was found for chemical burns among evening and night-shift workers. Increased interventions are needed to reduce occupational burns in work settings. Particular diligence should be should address occupational burn hazards in restaurant establishments, and preventative should be measures aimed at young employees and late-shift workers.

Assessment of occupational eye injury risk and severity: an analysis of Rhode Island workers' compensation data 1998-2002

BACKGROUND

Occupational eye injuries have been recognized as a serious health risk to workers and are in need of further investigation to develop effective interventions.

METHODS

Rhode Island workers' compensation claims of ocular injury between 1998 through 2002 (n=8,877) were examined. The Current Population Survey was used to estimate occupational employment levels as a baseline for rate calculations.

RESULTS

The estimated ocular injury claim rate was 32.9 per 10,000 workers (95% CI=32.3-33.6), with the cost of claims totaling $1,514,666 and averaging $171 per claim. The highest estimated claim rate of all occupations was found for construction laborers of 373.7 per 10,000 workers (95% CI=267.1-480.3). Relative to the durable manufacturing industry, the highest risk of injury resulting in disability indemnification was the wholesale trade industry (OR=2.18, 95% CI=1.19-4.01, P<0.05).

CONCLUSIONS

Many of the eye injuries reported were likely preventable. Greater diligence, training, and safety precautions are needed to reduce the risk of eye injury to employees.

Occupational injury among Rhode Island adolescents: an analysis of workers' compensation claims, 1998 to 2002

OBJECTIVES

We sought to examine occupational injuries sustained by adolescent workers during a 5-year period.

METHODS

Workers' compensation claims from Rhode Island were used to assess injuries of 15- to 19-year-old employees (n = 8321) from 1998 to 2002. Baseline employee population estimates were derived using the Current Population Survey.

RESULTS

The annual estimated adolescent claim rate was 6.6 per 100 workers (95% confidence interval = 6.1-7.1), with annual average costs of $614,182. Injury rates increased with employee age, hours worked, and for day and nightshift employees relative to evening shift workers. The highest proportion of claims by industry was in eating establishments, and the average indemnification duration was 13.0 days.

CONCLUSIONS

Specific emphasis should be placed on increasing safety training and preventative interventions for teenagers in hazardous occupations and for those working longer hours.

Occupational vehicular accident claims: a workers' compensation analysis of Oregon truck drivers 1990-1997

This study used workers' compensation data from Oregon from 1990 to 1997 to examine workers' compensation claims from vehicular accidents by truck drivers, and to calculate claim rate estimates using baseline data derived from the US Bureau of Census' Current Population Surveys. During this period, 1168 valid injury claims due to vehicular accidents were filed representing an accident claim rate of 50.3 (95% CI: 45.1-55.5) per 10,000 truck drivers annually. There were 19 work-related vehicular accident fatalities recorded in the data over the 8-year period. Of all claimants, males constituted the majority (80.7%), most were 35 years of age or younger (51.4%) and had less than 1 year of job tenure (51.0%). Truck driver claim rates due to vehicular accidents were lowest during the 6 a.m. to 12 p.m. period. The average amount of compensable lost work days per injury claim was 57.8 days (S.D.=124.7) and the median claim time was 16.0 days with the inter-quartile range being 53.5 days. The amount of lost work reported increased with the claimant's age. A total of US$ 11,642,635 was paid in claims for vehicular accidents of truck drivers in Oregon over the time examined, which averaged US$ 9966 per claim, with a median claim amount of US$ 2590 and inter-quartile range of US$ 7670. Claims citing sprains were the most frequently recorded injury experienced from vehicular accidents.

Incidence Rates, Costs, Severity, and Work-Related Factors of Occupational Dermatitis

Objectives To extend and update past research on occupational dermatitis by examining recent workers' compensation claims data.

DESIGN

Retrospective analysis of workers' compensation claims from Oregon (1990-1997).

SETTING

All dermatitis-related workers' compensation claims were merged with US census data to estimate rates of dermatitis by age, sex, occupation, and industry. Associated claim costs and disability times were also calculated from these data.

PARTICIPANTS

All individuals with accepted dermatitis claims (N = 611) were included in the analyses.

MAIN OUTCOME MEASURES

The overall claim rates of individuals by age, sex, industry, and occupation were estimated. Total costs and average disability time were computed. Monthly patterns of dermatitis claims were examined.

RESULTS

The average claim rate of occupational dermatitis was estimated to be 5.73 per 100 000 workers (95% confidence interval, 5.66-5.80). Statistically significant differences (P<.001) in claim rates by age, sex, industry, and occupation were found. More than 47% of all claimants had 1 year of job tenure or less. Employees in the farming, forestry, and fishing occupations and industries had significantly higher claim rates compared with employees in other occupations. The average cost per claim was $3552, and the average disability time was 23.9 days. Some temporal trends in claim rates were observed.

CONCLUSIONS

Occupational dermatitis remains a significant problem in workplace settings. In addition, certain types of occupations and industries seem to be particularly affected by occupational dermatitis. Interventions may be particularly valuable for workers with little job tenure.

Disabling and fatal occupational claim rates, risks, and costs in the Oregon construction industry 1990-1997

This study estimated injury and illness rates, risk factors, and costs associated with construction work in Oregon from 1990-1997 using all accepted workers' compensation claims by Oregon construction employees (N = 20,680). Claim rates and risk estimates were estimated using a baseline calculated from Current Population Survey data of the Oregon workforce. The average annual rate of lost-time claims was 3.5 per 100 workers. More than 50% of claims were by workers under 35 years and with less than 1 year of tenure. The majority of claimants (96.1%) were male. There were 52 total fatalities reported over the period examined, representing an average annual death rate of 8.5 per 100,000 construction workers. Average claim cost was $10,084 and mean indemnity time was 57.3 days. Structural metal workers had the highest average days of indemnity of all workers (72. 1), highest average costs per claim ($16,472), and highest odds ratio of injury of all occupations examined. Sprains were the most frequently reported injury type, constituting 46.4% of all claims. The greatest accident risk occurred during the third hour of work. Training interventions should be extensively utilized for inexperienced workers, and prework exercises could potentially reduce injury frequency and severity.

The impact of shift work on the risk and severity of injuries for hospital employees: an analysis using Oregon workers' compensation data

BACKGROUND

While past research on health care workers has found that shift work can lead to negative physiological and psychological consequences, few studies have assessed the extent to which it increases the risk of specific work-related injuries, nor quantified and compared associated types, severity and costs.

AIMS

This study aimed to derive and compare the rates, typologies, costs and disability time of injuries for various hospital worker occupations by day, evening and night shift.

METHODS

This study used Oregon workers' compensation claim data from 1990 to 1997 to examine the differences in hospital employee claims (n = 7717) by shift and occupation. Oregon hospital employee claim data, hospital employment data from Oregon's Labor Market Information System and shift proportion estimates derived from the Current Population Survey (CPS) were used to calculate injury rate estimates.

RESULTS

The injury rate for day shift per 10,000 employees was estimated to be 176 (95% CI 172-180), as compared with injury rate estimates of 324 (95% CI 311-337) for evening shift and 279 (95% CI 257-302), night shift workers. The average number of days taken off for injury disability was longer for injured night shift workers (46) than for day (38) or evening (39) shift workers.

CONCLUSION

Evening and night shift hospital employees were found to be at greater risk of sustaining an occupational injury than day shift workers, with those on the night shift reporting injuries of the greatest severity as measured by disability leave. Staffing levels and task differences between shifts may also affect injury risk.

An assessment of the effects of increased regulatory enforcement and legislative reform on occupational hearing loss workers' compensation claims: Oregon 1984-1998

BACKGROUND

Hearing loss from occupational exposures is a serious and widespread problem. This study measured the outcomes that increased enforcement of regulations and legislative interventions had on hearing loss workers' compensation claims.

METHODS

Workers' compensation claim data from Oregon was analyzed for the period of 1984-1998 to examine trends and severity of hearing loss claims. In 1987 and 1990, Oregon enacted legislative reforms to improve enforcement and promulgation of safety standards in the state. This study examined hearing loss claims between the periods of pre- and post-legislative reforms.

RESULTS

It was found that hearing loss claims decreased significantly following the legislative reforms, although the average cost per claim increased. Age and tenure effects, and evidence of moral hazard were also discovered.

CONCLUSIONS

Increased enforcement of regulations and legislative interventions by Oregon improved working conditions leading to occupational hearing loss. Nevertheless, hearing loss remains problematic, and continued efforts are required to improve worker safety.

Workplace Violence in Oregon: An Analysis Using Workers???Compensation Claims from 1990???1997

One of the most serious occupational problems in the workplace is the occurrence of violent assaults. This study examined 2028 workers' compensation claims of workplace violence from Oregon between 1990 and 1997, and used Current Population Survey data for risk analysis. The rate of workplace violence was 1.86 per 10,000 employees annually (95% confidence interval, 1.78-1.94), with females and workers under 35 years of age experiencing the most violence. The average claim resulted in approximately 40 days of indemnity and $6200 in costs. Workers on evening and night shifts had significantly higher rates of being victims of violence, as did those working on weekends. Preventative interventions should be targeted at younger workers and those with less tenure. Special measures should be focused on ensuring the safety of evening/night-shift workers and weekend employees.

Quantification and Risk Analysis of Occupational Burns: Oregon Workersʼ Compensation Claims, 1990 to 1997

This study examined all accepted Oregon workers' compensation claims for occupational burn injuries during the period of 1990 to 1997 (N = 3,158). The Current Population Survey was used to derive employee population baselines for establishing rate estimates. It was estimated that the average occupational burn claim rate was 2.89 per 10,000 workers (95% confidence interval [CI] 2.76, 3.02). The majority of claimants (71.7%) were males, the largest proportion (32.6%) was aged 25 years or less, and almost half (48.7%) had less than 1 year of job tenure. The most frequent burn type cited was heat/scald burns (78.9%) followed by chemical burns (19.3%). Costs averaged over 1.6 million dollars annually. The average indemnity period was 16 days. Higher relative risks were found for evening workers (2.97, 95% CI 2.96, 2.98) and night workers (2.13, 95% CI 2.12, 2.13) compared with dayshift workers. Kitchen workers had the highest burn rate of all occupations, with 62.5 claims per 10,000 workers.

Have health conditions associated with latex increased since the issuance of universal precautions?

OBJECTIVES

This study explored whether the prevalence of latex-related health conditions has increased among individuals employed in medical occupations relative to those employed in nonmedical occupations since the issuance of universal precautions in 1987.

METHODS

Data derived from the 1983 to 1994 versions of the National Health Interview Survey were used to obtain odds ratios comparing prevalence rates of latex-related symptoms over time.

RESULTS

No statistical evidence was found that the universal precautions resulted in increased prevalence rates of latex-related health conditions among medical workers relative to those employed in nonmedical occupations.

CONCLUSIONS

Increased use of latex gloves among health care personnel subsequent to the implementation of universal precautions appears to have had no effect on latex allergic reactions experienced by these workers.

Workers' compensation claims related to natural rubber latex gloves among Oregon healthcare employees from 1987-1998

BACKGROUND

Occupational reaction to natural rubber latex (NRL) glove use by healthcare employees has been an area of increasing concern. Unfortunately, there is little data demonstrating the prevalence and severity of actual reactivity to NRL.

METHOD

Occupational reaction to NRL was estimated using workers' compensation claims filed by healthcare employees in Oregon for the period of 1987-1998. For the first ten years, these claims were estimated by source and conditions consistent with NRL glove reactions, while in the last two years a specific code developed in 1997 for NRL glove reactions was also employed.

RESULTS

The claim rate was on average 0.58 per 10,000 healthcare workers annually, which constituted 0.29% of all workers' compensation claims. The most common condition experienced was dermatitis (80%) and most common body part affected was the hands (55.4%). The majority of claimants, 45 (69.2%), reported taking less than a month off work, suggesting most reactions were minor in nature, although one fatality was reported. The average NRL claim cost was $8,309.48. Overall the average cost per insured healthcare worker was approximately $0.50 per year. The occupational groups with the highest number of claims were nurses (30.8% of claimants) and nursing aides and orderlies (24.6% of claimants).

CONCLUSIONS

In comparison with other workers' compensation claims filed by healthcare workers during this period, 0.25% of the total was potentially related to NRL gloves. The rare incidence of respiratory and ocular claims is inconsistent with the hypothesis that asthmatic or conjunctival reactions to NRL gloves are common.

Assessing latex allergy among health care employees using workers' compensation data

Latex allergies among health care workers have garnered considerable attention from medical researchers and practitioners. However, the majority of research on natural rubber latex allergy has focused on clinical methodologies and emphasized the quantification of employee sensitization rates as opposed to actual incidents of reactivity. Workers' compensation data provide information on the number and impact of reactions to latex use. This article presents an analysis of health care workers' compensation data from North Dakota to estimate the prevalence, costs, and nature of claims associated with latex allergic reaction. The results show an annual average claim rate of 1.52 per 10,000 health care workers employed in the state, and annual costs averaging about $.08 per health care worker. Skin disorders were the most commonly reported condition. These findings are compared with previous studies of Minnesota and Rhode Island and demonstrate similar results.