Volume Pulse Amplitude Research Articles

The effects of intermittent noise on human serial decoding performance and physiological response.

The effects of continuous, periodic, and aperiodic broad band noise on serial decoding performance and on three physiological response measures were investigated. Performance data were recorded from 16 undergraduate university students using an electronically programmed rapid serial decoding task. The task configuration chosen combined a basic serial reaction function with a mental coding and short-term memory function. To assess activation or arousal effects of noise, three physiological variables were also simultaneously recorded: finger photoplethysmographic blood volume pulse amplitude, pulse rate, and forearm eleetromyogram. In addition, responses to a noise annoyance sensitivity questionnaire were used in an attempt to assign subjects to experimental groups such that noise annoyance sensitivity across groups would be constant. Each subject was isolated in a soundproof chamber while performance data and physiological data were collected under four counterbalanced conditions: work in quiet, continuous...

Desensitization of children to television violence.

Desensitization of children to television violence.

Relationship between the peak amplitude of the volume pulse and the blood flow in the digits of the healthy as well as patients with peripheral vascular diseases

Digital pulse volume and digital arterial inflow were measured using a mechanical plethysmography on 16 normal subjects, 17 patients with oedema and swelling of fingers as well as 15 patients with neurovascular syndroms.Higher pulse volume amplitude and increased digital blood flow were obtained in normal subjects compared with those of patients.A statistically significant correlation was noted between pulse wave volume and arterial inflow not only in normal subjects but also in two patients groups.The digital pulse volume, therefore, appeared to be reliable as an indicator of the peripheral blood flow as well as the digital arterial inflow.

STUDIES ON THE MUCOSAL CIRCULATION OF THE NASAL INFERIOR TURBINATE BY MEANS OF CdS PHOTOELECTRIC PLETHYSMOGRAPHY

Using CdS, the nasal reflexion photoelectric plethysmograph (R.P.P.) was made. This apparatus, tiny and extremely sensitive. recorded accurately the movement of blood flow through the mucous membrane of the human inferior turbinate as volume pulse.The tracing was simple and accurate. The following results were obtained.1) Two kinds of wave fluctuations were found on the R.P.P. of the nasal turbinate mucous membrane. One is the so-called respiratory fluctuation without having changes in the amplitude of volume pulse, and the other is the spontaneous fluctuations of longer periodicity at the time of quiet respiration of healthy persons.Respiratory fluctuation was remarkable when the inspiral air was cold. but it was not so remarkable on the finger R.P.P. Spontaneous fluctuations of the inferior turbinate on both sides are. in many cases. synchronous but it is not so between nose and fingers. The movements are bigger in nervous persons. but are seldom found in arteriolosclerosis.2) The vasomotor reflex which was brought about by means of deep breathing. breath holding. mental calculation. cold stimulation etc. showed remarkable vasoconstricting tendency on the finger plethysmogramm. However. the tendency of plethysmogramm of the nasal mucosa was rather weak and the total blood volume was considerably redu ced. Cold stimulation was especially. characterized by an increase of blood volume of the nasal inferior turbinate.3) The wave-forms of the R.P.P. of inferior turbinate showed more even rounded curve with less pinnales and dales than those of fingers. This fact is supposed to be attributable to the effect of endocardial pressure. which influences stronger nasal inferior turbinate than on fingers.4) It can be said. therfore. that the peripheral blood circulation in the nasal mucoa of inferior turbinate regurates itself by virtue of the A.V.A.. the polster-artey and the sinus plexus etc.

Investigation of arterial obstruction using a mercury-in-rubber strain gauge

The use of the mercury-in-rubber strain gauge to measure the circulation to the limbs is described. The instrument is quickly applied to the limb and can be used to make measurements of the circulation at many points on the limb. It has been used to measure blood flow, volume pulse, and systolic pressure at different levels on the limbs of normal subjects under various conditions and of patients with arterial disease. The range of these measurements in the legs of normal subjects is defined. The measurement of the systolic pressure gradient down the limb also gives a good indication of the location and degree of arterial obstruction or obstructions. The amplitude of volume pulse has been found to be a better indication of the location and severity of chronic arterial obstruction than are measurements of blood flow. This finding led to a consideration of the relationship between blood flow and amplitude of the volume pulse. An argument is put forward for considering the volume pulse as an indication of the degree of reserve of the peripheral circulation. The clinical application of the results in the selection of patients for arterial surgery is considered, and means are suggested by which an oscillometer could be used to provide information on the location and severity of obstruction of the larger arteries.

The mechanism of accelerated peripheral vascular sclerosis in diabetes mellitus

1. 1. An evaluation of the peripheral circulation was made in a group of forty-seven diabetic patients, employing the microplethysmographic method. All patients were below the age of forty-five years. 2. 2. Standard diagnostic technics failed to demonstrate any impairment of the peripheral circulation in each subject. 3. 3. Using the response to nitroglycerine as a test method, twenty-two of the forty-seven patients showed significant differences in blood flow and volume pulse amplitude in one great toe as compared with the contralateral toe. 4. 4. Following ganglionic blockade by tetraethylammonium, fifteen of these twenty-two patients continued to manifest significant reductions in flow and volume in one of the two halluxes. 5. 5. These findings are considered to imply the presence of occlusive peripheral vascular disease in these subjects. In view of the normal oscillometric index, the disease is localized to the digital bed. Similar vascular alterations have not been demonstrated in non-diabetic patients of similar age groups. 6. 6. It is suggested that the lesions in the digital bed are analogous to the vascular lesions of diabetic retinitis and intercapillary glomerulosclerosis, and constitute an integral manifestation and not a secondary complication of diabetes mellitus. 7. 7. The increased proximal resistance which will follow upon the development of a more distal occlusive angiopathy is considered to account, at least in part, for the increased incidence and accelerated development of clinical arteriosclerosis in diabetes. 8. 8. The alterations in the minute digital blood vessels appear to represent a vascular change distinct from the usual type of peripheral arteriosclerosis.