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Vol. 81. Núm. 5.
Páginas 479-484 (Setembro - Outubro 2015)
Original article
Open Access
Assessment of the light intensity of otoscopes utilized in teaching hospitals
Avaliação da intensidade da luz dos otoscópios em hospitais-escola
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Vinicius Ribas Fonsecaa,b, Giovana Bittencourt Bassoc,
Autor para correspondência
giovanabasso@hotmail.com

Corresponding author.
, Mariana Nagata Cavalheiroc
a Department of Otorhinolaryngology, Universidade Positivo, Curitiba, Paraná, PR, Brazil
b Department of Otorhinolaryngology, Hospital Cruz Vermelha, Curitiba, Paraná, PR, Brazil
c Department of Medicine, Universidade Positivo, Curitiba, Paraná, PR, Brazil
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Informação do artigo
Estatísticas
Figuras (2)
Tabelas (4)
Table 1. Mean and standard deviation of the total charge of batteries, and test battery charge ratio in relation to the new batteries.
Table 2. Mean and standard deviation of light intensity, and test battery light intensity ratio in relation to new batteries.
Table 3. Full battery charge and test battery ratio in relation to the new batteries of each otoscope.
Table 4. Light intensity and test battery light ratio in relation to the new batteries in each otoscope.
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Abstract
Introduction

To attain an accurate otoscopic diagnosis, a functioning device with adequate capacity must be used.

Objective

Evaluate the light intensity of otoscopes, comparing it utilizing the batteries present at the moment of calibration and after new batteries were supplied.

Methods

Cross-sectional study of a historical cohort, which assessed 38 otoscopes, measuring the light intensity with the batteries present at the moment of assessment compared to the intensity with new batteries, as well as charge of the test batteries and the new batteries.

Results

The mean of the sum of new batteries’ charge was 3.19V, and of the test batteries was 2.70V, representing a decrease of 18.02% in charge. The mean luminosity with the new batteries was 366.89lumens, whereas in the test batteries it was 188.32lumens, representing a decrease of 83.75% in the light intensity. Student's t-test was applied for data comparison, showing a statistical difference between the light intensity with the original batteries and the new batteries (p=0.0001; CI=0.95).

Conclusion

There was a statistically significant difference between the proportions of light intensity in the otoscopes. A small variation in battery charge results in a great variation in light.

Keywords:
Otoscopy
Otoscopes
Light
Resumo
Introdução

Para a realização de um diagnóstico otoscópico preciso deve-se utilizar um aparelho funcionando com uma capacidade adequada.

Objetivo

Avaliar a intensidade luminosa dos otoscópios comparando a intensidade da luz com as pilhas encontradas no momento da aferição e com pilhas novas.

Método

Estudo de coorte histórica com corte transversal, onde foram analisados 38 otoscópios, sendo realizada a aferição da qualidade luminosa com a pilha utilizada e comparado com uma pilha nova, e a aferição da carga das pilhas novas e em utilização no momento do exame.

Resultados

A média da soma das cargas das pilhas novas foi de 3,19V, e a das pilhas testes foi de 2,70V, representando decréscimo de 18,02% na carga das pilhas. A média da luminosidade com as pilhas novas foi de 366.89 lúmens, e com a pilha teste foi de 188.32 lúmens, representando decréscimo de 83,75% na intensidade luminosa. Foi aplicado o teste T para comparação entre os dados, onde percebe-se diferença estatística entre a intensidade luminosa com pilhas testes e novas (p=0,0000; IC=0,95).

Conclusão

Houve diferença estatisticamente significativa entre a proporção de intensidade da luz dos otoscópios. Uma pequena variação da pilha proporciona uma grande variação na luz.

Palavras-chave:
Otoscópios
Otoscopia
Luz
Texto Completo
Introduction

The otoscope is a medical device commonly used in both primary care and hospitals.1 The first otoscopes were designed for viewing the ear canal, as a pair of tweezers, similar to current rhinoscopes.1

Otoscopy is the main focus of the otological physical examination and should be performed with an appropriate otoscope that offers a good light source, preferably with halogen light (white) so as not interfere with the normal color of the outer ear and the middle ear structures.2 It should be attached to a disposable or sanitized otoscope speculum and be of an appropriate size for the ear conduit to be assessed.2

Adequate illumination of the tympanic membrane requires special equipment and an open and clean ear canal, but the circumstances are rarely optimal.3 Approximately one-third of physicians exchange the otoscope bulbs less often than recommended, and one-third of otoscopes do not have adequate lighting capacity.3

There are insufficient studies in the literature that have evaluated the ideal luminosity for good diagnostic accuracy or that have assessed the influence of battery power on the quality of light. There is only the study by Barriga et al., carried out in 1986, which evaluated the intensity of light of otoscopes, taking into account lamp replacement frequency.4

The present study aimed to evaluate the light intensity of otoscopes in outpatient clinics, offices, and emergency wards of teaching hospitals, by comparing the intensity of light with batteries found at the moment of measurement and with fully charged batteries.

Methods

The study was carried out with the authorization of Hospital da Cruz Vermelha (Paraná, Brazil) and Hospital Pequeno Príncipe, where data collection was conducted from June, 2013, to January, 2014. It was a historical cohort study with cross-sectional design, and as it did not involve human beings, approval from the research ethics committee was not necessary.

Selection of study site and the types of otoscopes

Two school hospitals were chosen to assess the quality of light of otoscopes in places with situations believed to be close to the ideal for symptomatic patient assessment.

This study evaluated not only the otoscopes of the institutions, but also those belonging to the physicians who agreed to participate in the study after a brief explanation of the study objectives.

The sample collection sites for assessment were: general outpatient clinic, emergency, otorhinolaryngology clinic, otorhinolaryngology offices, infirmary, and academic outpatient clinic of both hospitals.

The inclusion criteria were assessed otoscopes with halogen light, light-emitting diodes (LED), common lamp bulb, or optical fiber, powered by energy supplied by conventional batteries.

The exclusion criteria included otoscopes powered by electricity or power supply provided by rechargeable batteries, or those whose owners refused to participate.

A total of 38 otoscopes were assessed, of five different brands, Welch Allyn®, Missouri®, Piko®, Omni® and Mikatos®, of which six belonged to Hospital da Cruz Vermelha (Paraná, Brazil), with the remainder belonging to the service providers of the institutions.

Otoscope luminosity and battery intensity assessment

Test batteries were those found in the otoscopes at the time of assessment; new batteries consisted of Duracell® AA or C batteries bought by the researchers, depending on the type of otoscope, with charge>1.5V.

The charge of the test batteries of the otoscopes to be assessed was evaluated before the measurement of light intensity through a calibrated voltmeter to determine the charge level. Additionally, the new batteries with charge>1.5V were assessed, so that they could be verified as fully charged.

A dark box was constructed (Fig. 1), which did not allow light to enter after being closed, so that the otoscope light intensity assessment could be standardized without the influence of external light.

Figure 1.

Dark box.

(0,11MB).

An Icel® light meter, calibrated to a 2000lux sensitivity factor, had its photometer affixed to one of the box walls; the photometer was mobile and could be moved upward or downward, as it was fixed by Velcro® strips. Thus, it could be placed perpendicularly to the otoscope light extremity at the time of measurement.

The otoscopes were mounted on a holder prepared to keep it standing at 4cm from the basis and perpendicular to the photometer central point with a 3-mm mean speculum opening, according to the otoscope model (Fig. 2).

Figure 2.

Otoscope fixed at the base at a 4-cm distance and light source directed to the central point of the photometer.

(0,14MB).

After the otoscope was positioned, it was turned on and the box was closed, after which the light intensity was measured by the light meter. The maximum measured light intensity was recorded.

This procedure was first performed with otoscopes with the test batteries and then with the new batteries, to determine the proportion in percentage of light intensity in the otoscopes with the test batteries, considering 100% light intensity found with the new batteries for each tested otoscope. Data were collected by two researchers, who were together during all measurements, which were entered into a spreadsheet and submitted to statistical analysis.

Statistical analysis

The charge intensity of the test and new batteries and the proportion of light intensity of the otoscopes were compared using the Student's t-test for paired data, as they were compared with the results of the same otoscope, but with the different batteries, with a p-value<0.05 considered statistically significant.

Results

All otoscopes assessed in this study used two non-rechargeable batteries for their operation. The mean of the sum of the charges of the two new batteries was 3.19V, whereas the two test batteries had a mean value of 2.70V. This represented an 18.02% decrease in the mean charge of the two batteries (Table 1).

Table 1.

Mean and standard deviation of the total charge of batteries, and test battery charge ratio in relation to the new batteries.

  Mean  Standard deviation 
Full charge of test batteries (V)  2.70  0.32 
Full charge of new batteries (V)  3.19  0.02 
Test charge ratio (%)  84.73  10.31 
New charge ratio (%)  100 

The maximum light capacity in each otoscope was individually assessed and the value measured with the new batteries considered to be 100%. The mean intensity of the 38 assessed otoscopes was 366.89lumens. The mean intensity achieved with the test batteries was 188.32lumens, which shows that on average, the otoscopes functioned at 54.42% of their potential (Table 2).

Table 2.

Mean and standard deviation of light intensity, and test battery light intensity ratio in relation to new batteries.

  Mean  Standard deviation 
Test light intensity (lumens)  188.32  114.783 
New light intensity (lumens)  366.89  238.272 
Test light intensity ratio (%)  54.42  17.33 
New light intensity ratio (%)  100 

Otoscope 1 had the lowest battery power; it originally had only 40.9% of the maximum voltage and battery replacement generated a 100% improvement in light intensity (Tables 3 and 4).

Table 3.

Full battery charge and test battery ratio in relation to the new batteries of each otoscope.

  Sum of charge of test batteries (V)  Sum of charge of new batteries (V)  Test battery ratio (%)  New battery ratio (%) 
Otoscope 1  1.30  3.18  40.9  100 
Otoscope 2  2.62  3.18  82.4  100 
Otoscope 3  1.30  3.19  40.7  100 
Otoscope 4  2.34  3.16  74  100 
Otoscope 5  2.70  3.18  84.9  100 
Otoscope 6  3.00  3.16  94.9  100 
Otoscope 7  2.73  3.18  85.8  100 
Otoscope 8  2.38  3.22  73.9  100 
Otoscope 9  2.49  3.22  77.3  100 
Otoscope 10  2.60  3.23  80.5  100 
Otoscope 11  2.67  3.21  83.2  100 
Otoscope 12  2.84  3.22  88.2  100 
Otoscope 13  2.73  3.21  85  100 
Otoscope 14  2.64  3.22  82  100 
Otoscope 15  2.87  3.21  89.4  100 
Otoscope 16  2.43  3.21  75.7  100 
Otoscope 17  2.63  3.20  82.2  100 
Otoscope 18  2.77  3.21  86.3  100 
Otoscope 19  2.68  3.19  84  100 
Otoscope 20  2.38  3.20  74.4  100 
Otoscope 21  2.82  3.20  88.1  100 
Otoscope 22  2.74  3.19  85.9  100 
Otoscope 23  2.64  3.19  82.7  100 
Otoscope 24  2.85  3.18  89.6  100 
Otoscope 25  2.53  3.18  79.5  100 
Otoscope 26  2.87  3.18  90.2  100 
Otoscope 27  2.72  3.16  86  100 
Otoscope 28  3.04  3.16  96.2  100 
Otoscope 29  2.98  3.18  93.7  100 
Otoscope 30  2.94  3.18  92.4  100 
Otoscope 31  3.00  3.18  94.3  100 
Otoscope 32  3.08  3.18  96.8  100 
Otoscope 33  2.76  3.18  86.8  100 
Otoscope 34  3.00  3.16  94.9  100 
Otoscope 35  3.03  3.18  95.3  100 
Otoscope 36  3.00  3.11  96.5  100 
Otoscope 37  3.04  3.14  96.8  100 
Otoscope 38  2.42  3.16  76.1  100 
Table 4.

Light intensity and test battery light ratio in relation to the new batteries in each otoscope.

  Test battery light intensity (lumens)  New battery light intensity (lumens)  Test light ratio (%)  New light ratio (%) 
Otoscope 1  80  160  50  100 
Otoscope 2  183  264  69.3  100 
Otoscope 3  12  211  5.7  100 
Otoscope 4  256  656  39  100 
Otoscope 5  220  421  52.2  100 
Otoscope 6  168  362  46.4  100 
Otoscope 7  226  440  51.3  100 
Otoscope 8  177  398  44.4  100 
Otoscope 9  198  371  53.3  100 
Otoscope 10  234  487  48  100 
Otoscope 11  254  498  51  100 
Otoscope 12  290  497  58.3  100 
Otoscope 13  232  467  49.6  100 
Otoscope 14  211  401  52.6  100 
Otoscope 15  299  512  58.4  100 
Otoscope 16  179  399  44.8  100 
Otoscope 17  207  429  48.2  100 
Otoscope 18  243  432  56.2  100 
Otoscope 19  219  401  54.6  100 
Otoscope 20  188  359  52.3  100 
Otoscope 21  279  438  63.7  100 
Otoscope 22  226  430  52.5  100 
Otoscope 23  257  593  43.3  100 
Otoscope 24  265  575  46  100 
Otoscope 25  92  197  46.7  100 
Otoscope 26  96  169  56.8  100 
Otoscope 27  46  157  29.3  100 
Otoscope 28  96  145  66  100 
Otoscope 29  121  269  45  100 
Otoscope 30  231  341  67.7  100 
Otoscope 31  10  90  100 
Otoscope 32  10  11  90.9  100 
Otoscope 33  63  114  55.2  100 
Otoscope 34  370  393  94.1  100 
Otoscope 35  610  1420  42.9  100 
Otoscope 36  204  233  87.5  100 
Otoscope 37  38  51  74.5  100 
Otoscope 38  67  231  29  100 

A mean increase of only 18.02% in battery power results in an increase of 83.75% in light intensity. When assessing the 38 otoscopes by Student's t-test for data comparison, it can be observed that there was a significant difference between light intensity with test batteries and new ones (p=0.0000; CI=0.95).

Discussion

Medical practice demonstrates that otoscope illumination is critical for adequate patient otological assessment, and this examination is essential for the diagnosis and monitoring of otological pathologies.5

The otoscopes assessed in this study used non-rechargeable alkaline batteries, which, when new, have a total charge of 1.5V each. If the voltage is below 0.8V, the battery is surely exhausted; for voltages between 0.8 and 1.3V, the result is a weak unit; with voltages above 1.3V, the battery can be considered good.6 The mean charge of each analyzed battery was 1.35V, which is considered good, and even then, replacing it by a new battery offers a significant gain regarding light intensity. This can be clearly observed when shown in percentages, as an increase of at least 20% of battery charge results in an increase of over 80% in light intensity.

When comparing the increases in light intensity, it was not possible to perceive any rules on light intensity improvement. This fact is due to the difference in the lamps used in the otoscopes and the variety of assessed brands. As an example, consider otoscopes 1 and 3. Otoscope 1 showed a 100% increase in light intensity with an increase of 144% of battery power, while otoscope 3, with the same 144% increase in the battery power, showed an increase of approximately 1700% in luminosity.

In the study by Barriga et al., the authors assessed otoscopes located in 96 medical offices.4 The light output was measured in each otoscope and reassessed with a new lamp, and when possible, a new battery was placed in the unit.4

In approximately one-third of the otoscopes, the light output was suboptimal.4 Lamp replacement provided adequate illumination for 80% of the otoscopes.4 Barriga et al. observed that one-third of physicians change otoscope lamps annually, and less than two-thirds do so every two years (as recommended).4 In that study, almost half of rechargeable batteries were discharged.4 It was observed that lamp bulb replacement was more significant than replacing the battery to provide better luminous quality.4 As the lamp replacement would require a standardization of brand and type of lamp bulb (LED or halogen light), this study chose to evaluate only the influence of battery power on otoscope light.

One of the difficulties in performing this study was having access to otoscopes at the designated sites, as they were always being utilized for diagnosis. It was observed that the available otoscope in the study sites was not always that of the institution, which makes battery charge control difficult, as when the professional himself is the owner of otoscope, he/she is responsible for replacing batteries. In the Emergency Department of the Hospital da Cruz Vermelha (Paraná, Brazil) otoscopes are electric, which provides maximum luminosity, with the state of the lamp bulb representing the only influencing factor.

Regarding the methodology, the researchers had difficulty with the luminosity measurement method standardization, as many items can influence it, such as ambient light, the light direction in relation to the light meter, time of measurement, and the speculum size. The completion of the assessment in a controlled environment (dark box) with the light directed to the center of the light meter (perpendicularly), the use of a standard speculum opening (3.00mm), with the otoscope positioned on a flat surface and the possibility of changing the light meter height, allowed the standardization of the measurement methodology.

The authors propose other studies, comparing the influence of the battery power intensity and the exchange of the equipment lamps associated to a questionnaire directed to the assessing physician on the influence of the otoscope light intensity on the diagnosis of ear pathologies.

Conclusion

There was a statistically significant difference between the proportion of light intensity of assessed otoscopes when evaluated with the batteries used at the time of assessment and with new, fully charged batteries.

To carry out a more precise otoscopic diagnosis, attention should be paid to the importance of the maintenance of a well-functioning device, with the capacity close to the maximum, as a small variation in battery charge results in a much greater variation in light intensity.

Conflicts of interest

The authors declare no conflicts of interest.

References
[1]
F. Sánchez.
Historia de la ORL – otoscopio y rinoscopio.
GAES News, (2009), pp. 15
[2]
J.M.J. Soeira.
Concepção e desenvolvimento de um protótipo de um otoscópio óptico-electrónico.
Universidade do Porto, (2007),
[3]
M.E. Pichichero.
Acute otitis media: improving diagnostic accuracy.
Am Fam Physician, 61 (2000), pp. 2051-2056
[4]
F. Barriga, R.H. Schwartz, G.F. Hayden.
Adequate illumination for otoscopy. Variations due to power source, bulb, and head and speculum design.
Am J Dis Child, 140 (1986), pp. 1237-1240
[5]
A.S. Coco.
Cost-effectiveness analysis of treatment options for acute otitis media.
Ann Fam Med, 5 (2007), pp. 29-38
[6]
N.C. Braga.
Como testar pilhas e baterias.
Instituto Newton C. Braga, (2012),

Please cite this article as: Fonseca VR, Basso GB, Cavalheiro MN. Assessment of the light intensity of otoscopes utilized in teaching hospitals. Braz J Otorhinolaryngol. 2015;81:479–84.

Institution: Universidade Positivo and Hospital Cruz Vermelha, Curitiba, PR, Brazil.

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