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Biomedical subjects

A M Martin

Publications and source records attributed to A M Martin.

At least 91 records · Page 5Linked to original sources
PubMed1979

Dependence of acoustic attenuation of hearing protectors on incident sound level.

The relationship between incident sound level and acoustic attenuation for four types of earplug and four types of earmuff have been investigated using freshly prepared and instrumented cadaver ears. Pure tones and 1/3-octave bands of random noise in the frequency range 125-8000 Hz were employed as steady-state stimuli with sound pressure levels between 75 and 125 dB. Impulses with peak sound levels in the range 135-175 dB(P) were also presented. For the steady-state signals employed, the eight hearing protectors have been shown to have constant attenuation characteristics over the range of incident sound levels investigated. This was also the case for the six conventional protectors (with intentionally linear characteristics) for the impulse stimuli. The two intentionally amplitude-sensitive protectors provided attenuation which increased with incident sound level for impulse noises. Comparison of the protector attenuation-frequency characteristics determined for steady-state sounds shows good agreement with those obtained from subjective (threshold shift) national standard measurement procedures. It may be concluded, therefore, that the six conventional hearing protectors studied here have attenuation characteristics that are equal for incident sound levels at about 40 and 75 dB, and that they are constant for levels between 75 and 175 dB. Consequently, the results of national standard threshold-shift procedures, although measured at low sound levels, may be applied with confidence to occupations where hazardous high-level noises are present.

Acoustic Stimulation↗
PubMed1979

Epsilon aminocaproic acid (EACA) myopathy.

Two female patients developed a severe, painful proximal myopathy after taking 18--30 g of epsilon-aminocaproic acid daily for 5 weeks. Marked elevations of serum aminotransferases, creatine kinase and aldolase levels were found and the first patient had electromyographic and muscle biopsy changes of an acute monophasic, necrotising myopathy at the height of the illness. Resolution occurred in both cases on stopping the drug and the second patient had no electromyographic or muscle biopsy abnormalities 3 weeks later. Only 2 recognized cases of the condition have been reported previously but a review of the literature revealed several other possible examples.

Aged↗
PubMed1977

The release of plasticizer from polyvinyl chloride haemodialysis tubing.

The extent of migration of plasticizer from haemodialysis lines into saline and plasma has been examined and a number of different types of tubing have been compared. A model system designed to simulate in vivo haemodialysis was evolved. The method uses a continuous cyclohexane extraction in order to mimic uptake of plasticizer by body tissues. Although not an ideal system, the results obtained are indicative of the extent to which the plasticizers are leached.

Adipates↗
PubMed1975

Regular short haemodialysis in end-stage renal failure.

A study was made of thrice weekly haemodialysis of 3-3 1/2 hours' duration using a large surface area dialyser in patients with end-stage renal failure. Body water, potassium, and blood pressure control were satisfactory and comparable with the more widely used long dialysis schedules (6-9 hours thrice weekly). Patient rehabilitation was improved overall and the regimen enabled the dialysis unit to treat more patients despite a reduction in technical and nursing staff. The technique proved inadequate, however, in two patients with an intercurrent infection, and more intensive dialysis in recommended in such cases.

Blood Pressure↗