Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Ear Protective Devices”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources
PubMed1985

Hydrogen sulfide and the probabilities of 'inhalation' through a tympanic membrane defect.

We conclude that workers with tympanic membrane defects (perforated eardrums) should not be excluded from working in atmospheres containing concentrations of hydrogen sulfide (H2S). Several existing requirements and recommendations exclude workers with perforated eardrums from working in or around H2S. Such protective measures stem from the belief that H2S can enter the body through the perforation in sufficient measure to compromise the wearer's respiratory protection. However, based on calculations of anticipated leakage of H2S for a variety of eustachian tube conditions and in the absence of either medical literature or personal reports documenting H2S poisoning due to eardrum perforation, the recommendation for excluding workers with such a condition from working in or around H2S is not supported. The anatomy, physiology, and pathology of the eustachian tube are discussed, including the effects such devices as tympanomaxillary shunts might have on contaminant leakage. The National Institute for Occupational Safety and Health (NIOSH) criteria for respirator tests and sources of respirator leakage are examined and NIOSH recommendations for respiratory protection against H2S are outlined.

Ear Deformities, Acquired↗
PubMed1990

Reconstruction of the ossicular chain using a multistrand wire spring prosthesis.

A multistrand wire spring prosthesis is presented for ossicular reconstruction. This device offers a workable solution not only to the ossiculoplasty problems associated with lateralization of the tympanic graft and displacement of the prosthesis, but also to other problems such as fixation to middle ear wall, tissue reaction, resorption, degeneration, biodegradation, or poor sound conduction, which are obviated using a stainless steel wire for the ossicular prosthesis. The spring also protects the inner ear from external trauma. Long-term reconstruction results of 14 cases using first generation coil spring prosthesis are presented. A freely mobile prosthesis head composed of cartilage with perichondrium on a wire-mesh platform distributes pressure evenly to the undersurface of the tympanic membrane and further ensures the prevention of pressure necrosis and extrusion. When the handle of the malleus is present, the head-loop assembly of the spring prosthesis is designed to securely capture the handle. There is no practical loss of sound energy passing through the spring. Over a period of 14 years none of the wire prosthesis was found to have eroded through the stapedial footplate.

Bone Conduction↗
PubMed2002

The health of the workers in a rapidly developing country: effects of occupational exposure to noise and heat.

Occupational hygiene and safety have not been high on the agenda of industrial management in developing countries for a variety of reasons. This cross-sectional study was undertaken to assess the exposure to noise and heat, and to study the level of occupational hygiene practiced, at a foundry in a rapidly developing country (Dubai, United Arab Emirates). Audiometry, muscle cramps and visual acuity were measured in workers at a foundry and compared with the results from workers at a soft-drink bottling plant. Thermal stress, relative humidity, ventilation, illumination and noise levels were measured at different work units at the foundry and at the soft-drink bottling factory. Thermal stress index was high while relative humidity and ventilation were low at the foundry compared with the bottling plant. Noise levels were also high at the foundry, exceeding 90 dB at almost all work units except the fabrication workshop. Mild or moderate visual defects were observed among 31% of foundry workers, compared with 19% of the bottling plant workers.Muscle cramps were reported by 30% of all workers at the foundry, compared with 5% at the bottling plant. Visual disability was the highest among furnace operators and fabricators. Mean hearing disability was 8.69 +/- 1.08% among foundry workers, compared with 4.56 +/- 0.82% among bottling plant workers. The high thermal stress, noise levels and exposure to non-ionizing radiations at the foundry might have contributed to the higher frequency of muscle cramps and the greater hearing and visual disabilities, respectively, among these workers. Non-use of personal protective equipment and poor occupational hygiene and safety measures were also seen to affect eye and ear health adversely among the workers at the foundry.

Cross-Sectional Studies↗
PubMed1993

Eye protection in ear, nose and throat surgery.

The aim of this study was to quantify the risk of blood splashes to the conjunctiva during ear, nose and throat surgery. Two hundred and sixty consecutive operations by three surgeons were assessed for contamination of safety glasses and other factors. We found that 15 per cent of operations resulted in blood droplet contamination of safety glasses. In 92 per cent of these, contaminations were on the exterior of the glasses and eight per cent were on both sides. We concluded that about one and a half per cent of operations would result in droplet contamination of the conjunctiva and that safety spectacles reduced the risk by a factor of about 10. This study generally concurs with that of previous research in the areas of general and orthopaedic surgery and necropsies. We substantiate the need for eye protection for all ear, nose and throat procedures. Spectacles do provide a reasonable degree of protection but where absolute protection is needed i.e. in high risk groups, goggles should be used in preference to safety spectacles.

Blood-Borne Pathogens↗
PubMed2004

[Experimental joint incus-stapedial injuries in scanning electron microscopy].

Because all machines and vibration devices also produce noise, the combined activities of both factors are usually examined together. The opinion dominates that vibration exerts only a weak, additionally traumatic influence on the hearing organ. The aim of our investigation was to determine the influence of long-term, whole-body vibration on the incudo-stapedial joint which integrity is indispensable for the protection of the inner ear from the effect of noise. To realize the experimental conditions, sinusoidal vertical shaking (10 Hz, 5 mm, 1.4 g rms), an own noiseless apparatus was consisted. The experiment was carried out on 30 young, healthy, colored guinea pigs. They were subjected to vibration over 1, 3, and 6 months (132, 396, and 792 hours). The investigation was based on examination of the structures of the incudo-stapedial joint in the scanning electron microscopy. Among experimental animals two kinds of changes were ascertained which can be attributed to the activity of vibration. One was an extensive damage to the surfaces of the incudo-stapedial joint itself. The other was an often observed thickening of the bursa of the joint. The frequencies of occurrence and stages of advancement of both were in direct relationship to the duration of the experiment. The evaluation of the observed changes permits an explanation of the mechanism of the damage to hearing of persons subjected to noise and vibration. Whole-body vibration damages the incudo-stapedial joint, making its separation difficult. This may, than, facilitate the transfer of noise and its injurious influence to the inner ear.

Animals↗
PubMed2000

Sound and the developing infant in the NICU: conclusions and recommendations for care.

OBJECTIVE: To present the conclusions and associated recommendations for care developed by the Physical and Developmental Environment of the High-Risk Infant Center, Study Group on Neonatal Intensive Care Unit (NICU) Sound, and the Expert Review Panel. STUDY DESIGN: A multidisciplinary group of clinicians and researchers reviewed the literature regarding the effect of sound on the fetus, newborn, and preterm infant and developed recommendations based on the best evidence. An Expert Review Panel reviewed the data and conclusions. RESULTS: The following recommendations are developed from the review of the literature and are clarified in the body of the article. (1) Women should avoid prolonged exposure to low-frequency sound levels (< 250 Hz) above 65 dB(A) during pregnancy. (2) Earphones or other devices for sound production should not be used directly attached to the pregnant woman's abdomen. (3) The voice of the mother during normal daily activities, along with the sounds produced by her body and those present in her usual surroundings, is sufficient for normal fetal auditory development. The fetus does not require supplemental stimulation. Programs to supplement the fetal auditory experience cannot be recommended. (4) Infant intensive care units should incorporate a system of regular noise assessment. (5) Sound limit recommendations are to maintain a nursery with an hourly Leq of 50 dB(A), an hourly L10 of 55 dB(A) and a 1-second Lmax of 70 dB(A), all A-weighted, slow response scale. (6) Infant intensive care units should develop and maintain a program of noise control and abatement in order to operate within the recommended permissible noise criteria. (7) Care practices must provide ample opportunity for the infant to hear parent voices live in interaction between parent and infant at the bedside. (8) Earphones and other devices attached to the infant's ears for sound transmission should not be used at any time. (9) There is little evidence to support the use of recorded music or speech in the environment of the high-risk infant. Audio recordings should not be used routinely or left unattended in the environment of the high-risk infant. CONCLUSION: The recommendations, if followed, should provide an environment that will protect sleep, support stable vital signs, improve speech intelligibility for the infant, and reduce potential adverse effects on auditory development.

Animals↗
PubMed2001

Measurement of sound emission by endoscopic lithotripters: an in vitro study and theoretical estimation of risk of hearing loss in a fetus.

BACKGROUND: There is concern about applying intraureteral lithotripsy in pregnant patients, as the sound created by the equipment may damage fetal hearing. MATERIALS AND METHODS: The sound intensities produced by electrokinetic, pneumomechanic, holmium laser, ultrasound, and electrohydraulic intraluminal lithotripters were measured in an in vitro model. RESULTS: The purely mechanical modalities (electrokinetic and pneumomechanic) generated lower peak pressures than the other devices. Theoretical calculations were performed based on the fact that in vivo, the sound path and the fetal middle ear cavities are filled with fluid. Calculated pressure levels that give displacement amplitudes of the tympanic membrane, the ossicles, and the basilar membrane comparable to hearing loss risk criteria for airborne impulsive noise are greater than measured for all of the lithotripters. The fluid-filled middle ear thus seems to give the fetus protection against sound. The fluid also improves the symmetry of the cochlea structure, reducing the influence of direct bone transmission. CONCLUSIONS: The peak pressure of the sound emitted by lithotripsy in the ureter during pregnancy is unlikely to be harmful to fetal hearing. Other risk factors, such as the form of the sound waves and the pulse duration were not evaluated. The theoretical assessments are simplified, and one should be careful about drawing conclusions from theoretical considerations and calculations alone.

Endoscopy↗
PubMed1976

Investigation of acoustic trauma from the airbag.

Since the automobile-airbag passive restraint system may be in general use in early 1976, and, the fact, is now an opinion on some automobiles, its potential biomedical hazards need to be examined. The objective of this study was to investigate the effects of local slap pressure of airbag deployment against the external ear and tympanic membrane and to measure its effects on subsequential hearing acuity. Adult and infant squirrel monkeys were used as experimental subjects. To create an adequate simulation of the airbag trauma, a small airbag was fabricated and mounted on a pneumatic impact facility. This device was designed to produce a specific velocity to determine the behavior of objects under impact conditions simulating accident kinematics. Cochlear nerve action potentials were measured in both ears of 10 subjects prior to blast, immediately post-blast and several weeks post-blast. High-speed photography recorded events of the blast as well as the technique of recording the electrical potential from the cochlea. No permanent hearing damage, eardrum perforation, disruption of ossicles, or loss of hair cells occurred at airbag velocities up to 100 mph and a sound intensity level of 150 db.

Age Factors↗
PubMed1991

Tympanic membrane injury in welders: is prevention neglected?

Injury to the ear in welders is a recognized but poorly documented entity. Five cases are described to demonstrate a spectrum of severity of injury, ranging from minor burns to tympanic membrane perforation requiring myringoplasty. Welders are most at risk when working overhead, in cramped conditions or adjacent to other welders. Conventional safety helmets offer inadequate protection to the ears and it is recommended that insert ear plugs should be offered to all workers at risk, in addition to safer working practices. An increased awareness of these risks among occupational physicians, welders and employers is required before these recommendations can realistically be implemented.

Adult↗
PubMed2005

Importance of bone-conducted sound transmission on patient hearing in the MR scanner.

PURPOSE: to evaluate the influence of bone-conduction in the MR environment compared to a standardized acoustic environment. MATERIALS AND METHODS: Acoustic noise is an unwanted side effect of MRI that is commonly tackled with passive hearing protection. In an MR scanner, however, with the patient completely surrounded by the MR sounds and in close contact with the vibrating MR table and gantry, bone-conduction may increase subjective sound levels, restricting the efficacy of passive protection that reduces air-conducted noise only. A total of 10 volunteers were subjected to pure MR tones, covering the frequency range relevant for hearing and at 60 dB, generated through the MR system's gradient coils. Bone-conduction was determined for various passive damping conditions in an MR scanner and was compared to that acquired in an acoustically-calibrated environment. The contribution of mechanical vibrations to bone-conduction was determined. Also, with a microphone in the ear canal, the objective efficacy of the passive protection was measured. RESULTS: We found no difference between the bone-conduction experiments executed inside the imager and in the acoustically-controlled environment. The overall insertion loss of the passive hearing protectors was over 20 dB with strongest effects at 0.4 and 2.5 kHz. CONCLUSION: As bone-conduction is not more pronounced inside the MR scanner than outside, the previous reports on the subjective evaluation of protection devices in MRI hold their validity.

Bone Conduction↗
PubMed1989

Analysis of hurling and camogie injuries.

In 1984, 4500 people with sport injuries attended the Cork Regional Hospital. Of these, 817 were injured in the national game of hurling and camogie. Hand injuries were the most frequent occurring in approximately one third of injured players (33 per cent) and of these, just half had a closed metacarpal fracture. Facial injuries were the second most frequent category (28 per cent). Almost one third of these were nasal fractures, while forehead and eyebrow lacerations, fractured zygoma, loss of teeth are also common. Sport eye injuries referred to the Eye, Ear and Throat Hospital in Cork during the same period amounted to 107, of which 26 occurred in hurling. It is believed that a properly designed protective head gear would largely eliminate such facial and eye injuries.

Adult↗
PubMedDate not supplied

Noise and hearing loss.

The National Institutes of Health Consensus Development Conference on Noise and Hearing Loss brought together biomedical and behavioral scientists, health care providers, and the public to address the characteristics of noise-induced hearing loss, acoustic parameters of hazardous noise exposure, individual and age-specific susceptibility, and prevention strategies. Following a day and a half of presentations by experts and discussion by the audience, a consensus panel weighed the evidence and prepared a consensus statement. Among their findings, the panel concluded that sounds of sufficient intensity and duration will damage the ear and result in temporary or permanent hearing loss at any age. Sound levels of less than 75 dB(A) are unlikely to cause permanent hearing loss, while sound levels above 85 dB(A) with exposures of 8 hours per day will produce permanent hearing loss after many years. Current scientific knowledge is inadequate to predict that any particular individual will be safe when exposed to a hazardous noise. Strategies to prevent damage from sound exposure should include the use of individual hearing protection devices, education programs beginning with school-age children, consumer guidance, increased product noise labeling, and hearing conservation programs for occupational settings. The full text of consensus panel's statement follows.

Aging↗
PubMed2005

Occupational hygiene in a waste incineration plant.

The Turku incineration plant was renovated in 1995 to meet the emission requirements of modern waste combustion facilities. It treats presorted municipal waste from 170,000 residents in the Turku area. In the plant, the incineration process produces several types of by-products having importance in terms of occupational hygiene. Although not obligated by the law, the management of the plant has a keen interest in occupational hygiene at the plant, which was studied from 1998 to 2001. Concentrations of microbes, endotoxins, and dust and the noise level were investigated in three different working areas. Microbe measurements were conducted with a six-stage impactor and using the CAMNEA method. Especially in the measurements of viable fungi and actinomycetes, the six-stage impactor gave better results than the CAMNEA method. Concentrations of bio-aerosols and the level of noise were high enough in the waste bunker to be occasionally harmful to the health of employees. The endotoxin concentration could also be harmful to health in the combustion area, and the noise level there exceeded the Finnish threshold value of 85dBA. The total number of microbes (viable+dead) was high in a few measurements in the crane room. One reason for these high numbers was prior moisture damage, which was repaired in 2000. The use of ear protectors is advised in the bunker area and in the combustion area. Use of respirators (class P3) is advised in the bunker area to prevent the exposure of employees to bio-aerosols.

Aerosols↗
PubMed1995

Respirator proposal loses breath when applied to health care.

The debate continues. As Materials Management in Health Care went to press, the Occupational Safety and Health Administration was getting an earful about proposed revisions to its respiratory protection standard. The standard sets requirements for respirator use in the workplace and will be a basis for part of OSHA's proposed tuberculosis standard, which should be released later this year. Here are the American Hospital Association's comments on the proposed revisions.

American Hospital Association↗
PubMed2001

A radiation-shielding device for craniofacial implant placement.

The use of radiation shields in the head and neck cancer patient receiving adjuvant radiation therapy is a treatment alternative for protecting anticipated prosthetic implant sites. Shields can be fabricated easily as part of an interdisciplinary treatment protocol. In this article, the methods used to fabricate an extraoral radiation shield are described, and a patient treatment that illustrates possible uses of the shield for both extraoral and intraoral sites is presented.

Aged↗
PubMedDate not supplied

Telephone communications with several commercial respirators.

Previous work showed that telephone communications while wearing military respirators degraded both word comprehension and recognition speed. In addition, electronic amplification of the speech diaphragm signal had shown no advantage to the extra hardware. This experiment was performed to test effects of different configurations of commercially available respirators on telephone communications accuracy and speed. Twelve pairs of subjects were separated into different rooms and communicated by telephone. Modified rhyme-test words were presented by computer to the speaker, who transmitted the word by telephone to the listener. During the first replication, subjects were given no instruction about telephone communications procedure. During the second replication subjects followed a communications protocol that instructed them when to move the telephone handset from their ears to their mouths. Results showed that the protocol uniformly improved communications accuracy without incurring any extra time penalty. Word comprehension was still twice as fast without a respirator as with a respirator. Accuracy with the protocol nearly equaled the no respirator control value for most respirators tested.

Adolescent↗
PubMed2002

Effect of millimeter waves on cyclophosphamide induced suppression of the immune system.

The effect of millimeter electromagnetic waves (MWs) on cyclophosphamide (CPA) induced toxicity to leukocytes, bone marrow cells, and T-cell-mediated immunity was examined. For studying the effect of MWs on CPA induced leukopenia and myelosuppression, BALB/C mice were irradiated for 3 days, 30 min each day, prior to administration of CPA (200 mg/kg). MWs were produced with a Russian made YAV-1 generator. The device produced 42.2 +/- 0.2 GHz modulated wave radiation through a 10 mm x 20 mm rectangular output horn. The animals were irradiated on the nose area. Peak SAR and incident power density were measured as 622 +/- 100 W/kg and 31 +/- 5 mW/cm(2), respectively. For studying the effect of MWs on CPA induced suppression of T-cell mediated immunity, a delayed type hypersensitivity (DTH) assay in mouse skin was used. The DTH reaction in mouse skin was induced by topical application of dinitrochlorobenzene (DNCB) and quantified by measuring the increase in ear thickness and by histological examination. Treatment of animals with CPA significantly (P < 0.05) reduced leukocyte and bone marrow cell population, but MW irradiation did not show any significant protection from the immunosuppressive effects of CPA. Furthermore, MW irradiation did not protect the animals from CPA induced suppression of T-cell mediated immunity.

Administration, Topical↗
PubMed2002

Helmet design to facilitate thermoneutrality during forest harvesting.

The purpose of this investigation was to evaluate the ventilatory characteristics of vented and non-vented helmets for use in forestry harvesting operations. A ventilation index developed by Birnbaum and Crockford (1978) was used to determine the ventilation capacity of twelve helmets varying in design and presence, location, and dimension of vents. Helmets with top vents had higher ventilation indices than non-vented, side and side/top-vented helmets. Ten physically fit men participated in a maximal oxygen consumption test and four trials wearing a non-vented, round-side-vented, round-top-vented or rectangulartop-vented helmet. Trials simulated typical summer environmental conditions (28 degrees C, 80% rh) and physiological work loads (40% VO(2)max) experienced during forest harvesting in New Zealand. The temperature and humidity under the helmet was typically lowest when the helmet with the largest vented area (288 mm(2)) in the crown was worn, although physiological responses (temperatures at the tympanum, ear and scalp; humidity at the centre of the helmet) of the participants to wearing the helmets differed significantly during some rest periods only. Top-vented helmets (in this experiment measured 288 mm(2)) should be worn to minimize temperature and humidity of the head during forest harvesting operations.

Adaptation, Physiological↗