Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PLETHYSMOGRAPHY”

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 559 records · Page 31Linked to original sources
PubMed1984

[Automatic finger plethysmography as a human pharmacologic research tool. A methodologic study].

In view of the use of an electronically processed digital plethysmography as a noninvasive pharmacological tool - particularly to measure effects of organic nitrates - 9 healthy young volunteers were examined. The purpose of the investigation was to study baseline recordings and to assess the effects of several well defined exogenous influences. The electronic processor calculated the D/H-ratio of each plethysmographic pulse wave, where D represents the depth of the dicrotic minimum measured from the apex of the systolic maximum and H the total hight of the plethysmographic wave. The D/H-ratio was not significantly influenced by a hot beverage, but fell after a cold drink. In undisturbed volunteers the D/H-ratio had a tendency to fall slightly during a 3-h period of observation. This tendency could be eliminated by small doses of pindolol or dihydroergotamine, but individual fluctuations of the curves were still visible. It appears therefore that a fully automated evaluation of plethysmographic recordings yields best results if the findings in a group of volunteers are averaged.

Adult↗
PubMed1983

The diagnosis intermittent claudication. The value of walking test, ankle pressure index and calf plethysmography in relation to the clinical findings.

Three hundred and forty-nine patients with the diagnosis intermittent claudication (IC) based on Rose's questionnaire were all found to have clinical abnormality based on pulse palpation, and/or auscultation in lower abdomen and groin. The diagnosis was in the majority of cases (87-95%) confirmed by standardized walking test (WT), ankle pressure index (AI) and venous occlusion calf plethysmography (VOP). In clinical abnormality based on bruit only in groin, AI and VOP confirmed the diagnosis less frequently than in the other clinical abnormalities (p less than 0.01).

Adult↗
PubMed1983

After-exercise thermography compared to strain-gauge plethysmography and venous pressure measurements to detect deep venous insufficiency.

After-exercise thermography (AET) has been claimed to be a means of detecting deep venous insufficiency. The question was studied in 167 patients four to five years after major surgery. The tests af follow-up included AET, strain-gauge plethysmography and venous pressure measurements in addition to clinical examination and a questionnaire concerning history, symptoms etc. No correlation was found between abnormal AET and objective manifestations of deep venous insufficiency.

Aged↗
PubMed1983

[Multisegmental dynamic plethysmography for noninvasive study of venous function with special reference to exercise hyperemia].

Multilevel dynamic strain gauge plethysmography was evaluated in 22 healthy subjects. Venous volume changes were measured at the foot and calf level during tip-toeing exercise and at the thigh level during kneebends. These normal data were compared to those in 26 patients with chronic venous incompetence (CVI). Two types of curve resulted in the healthy subjects: if sensing site and exercised musculature do not correspond (foot sensing and calf-muscle exercise), venous volume decreases during exercise and stays on a constant level. However, if sensing site and exercised muscles are identical (calf--tip-toeings; thigh--kneebendings), venous volume increases again during exercise after a maximum volume decrease. This could be quantified by the volume increase angle beta. These mechanisms can be explained by exercise hyperemia. In patients suffering from CVI with only partially recanalized thrombotic occlusions, venous drainage is not sufficient and results in a significantly reduced (p less than 0.001) decrease in venous volume during exercise at the calf, or even in a volume increase. In the foot segment examined, however, no significant differences were found. Additional measurements at the thigh level are recommended for patients with a history of iliac vein thrombosis, especially for objective evaluation of intermittent venous claudication.

Adult↗
PubMed1983

[Modification of arterial blood flow using venous occlusion plethysmography].

Arterial blood flow volume was registered simultaneously by pulsed Doppler and venous occlusion plethysmography in 14 limbs of healthy subjects aged 25 to 36 years. The results were as follows: from the beginning of venous occlusion and during venous filling phase, arterial flow diminishes to 73% of its initial value. This diminution is due to a progressive decrease in arterial systolic flow as well as an increase in diastolic arterial reflux. The results reflect the increase in peripheral resistance as well as the elasticity of the arteries, which, during the diastole, return upstream a part of the arterial systolic flow.

Adult↗
PubMedDate not supplied

[Plethysmography in venous pathology].

The plethysmography is an easy and precise and therefore interesting non invasive investigation technique in search for deep venous obstructions. It is giving a well defined picture of the venous function and offers the possibility to differentiate most of the cases with a post-thrombotic syndrome from primary varicosis and to make the follow-up of the surgical treatment of venous anomalies.

Diagnosis, Differential↗
PubMed1984

[Peripheral circulatory effects of sodium nitroprussate. Evaluation by plethysmography and capillaroscopy].

Circulatory effects of intravenous injection of sodium nitroprusside are appreciated in 6 patients by monitoring systemic pressure, heart rate, digital systolic pressure, pulse plethysmography and nail-fold capillaroscopy. Low doses of nitroprusside (1.5 microg./kg/mn) enhance digital blood flow (+ 78.9%) and maximum height of the plethysmographic curve (+ 71.6%), without any significant modification of the systemic blood pressure (- 0.6%), heart rate (+ 6.3%) and digital pressure (- 1.15%). The peripheral resistances are strongly reduced. Nail fold capillaroscopy is unchanged. Higher doses, even with an adequate vascular filling, are potentially harmful for microcirculation.

Adolescent↗
PubMed1982

Noninvasive assessment of portal-systemic shunting: evaluation of a method to investigate systemic availability of oral glyceryl trinitrate by digital plethysmography.

The systemic availability of oral glyceryl trinitrate may be a measure of the fraction of portal blood bypassing the hepatocytes through portal-systemic shunts. In order to test this hypothesis without the need for blood sampling, measurements of drug concentrations in plasma were replaced by assessments of pharmacologic effects by using digital plethysmography. Dose-response curves resulting from graded intravenous infusions of glyceryl trinitrate (8 and 25 microgram/min) were used as standard of comparison for the pharmacologic response resulting from an oral dose of 800 microgram. In 9 normal volunteers, systemic availability of oral glyceryl trinitrate was 2 +/- 4% SD. In 7 patients with end-to-side portacaval shunts it was 94 +/- 18%, in 3 patients with distal splenorenal shunts 57 +/- 11%, and in 10 patients with cirrhosis of the liver it varied between 15% and 85%. Systemic availability of glyceryl trinitrate was negatively correlated with the initial plasma disappearance rate of sulfobromophthalein (r = -0.72, p less than 0.01). No significant correlation was found with the galactose elimination capacity (r = -0.12, n = 17). The lack of systemic availability of glyceryl trinitrate in healthy volunteers together with an availability close to 100% after end-to-side shunts is compatible with a very high hepatic extraction of the test compound by the normal liver, and with the idea that the systemic availability of of oral glyceryl trinitrate comes close to representing portal-systemic shunting. The procedure is rapid, essentially noninvasive, and well tolerated by patients.

Administration, Oral↗
PubMed1983

Impedance plethysmography. Noninvasive diagnosis of deep venous thrombosis and arterial insufficiency.

The versatility of impedance plethysmography (IPG) in the diagnosis of arterial and venous disease was evaluated in the clinical setting. Eighty-eight consecutive patients suspected of acute or chronic deep venous thrombosis (DVT) and undergoing ascending venography were evaluated using IPG. Venous capacitance (VC) and venous outflow (VO) were expressed as a per cent impedance change (% delta I). The evaluation was considered as abnormal if the VC was less than 1.85% delta I and the VO less than 0.95% delta I. The overall accuracy was 90 per cent with a sensitivity of 92 per cent and specifity of 93 per cent. Arterial blood flow (ABF) was measured in normal volunteers (20 limbs) and patients with intermittent claudication (20 limbs) and rest pain (16 limbs). Resting ABF (cc/100 ml/min) did not differ (P greater than 0.05) in the normal volunteer (4.3 +/- 0.4) and patients with intermittent claudication (4.6 +/- 0.5), but both were significantly greater (P less than 0.05) than ABF in patients with rest pain (3.2 +/- 0.2). Peak ABF during reactive hyperemia (RH) was significantly greater (P less than 0.001) in normal volunteers (24.8 +/- 1.6) than in claudicators (10.5 +/- 1.3), and both flows were significantly greater (P less than 0.0001) than the peak ABF in patients with rest pain (5.3 +/- 0.5). IPG may be used in the assessment of arterial and venous disease. It provides a sensitive test with which to screen patients with suspected DVT. In addition, it is a valuable adjunct in differentiating normal limbs from those with intermittent claudication and/or rest pain.

Arterial Occlusive Diseases↗
PubMedDate not supplied

Noninvasive detection of axillary and subclavian venous thrombosis by impedance plethysmography.

Venous occlusion impedance plethysmography (IPG) is an objective noninvasive test which is widely employed for the detection of deep venous thrombosis (DVT) in the lower extremities. The IPG technique is easily adapted to the evaluation of upper extremity venous thrombosis, as demonstrated in 46 patients with symptoms of axillary and subclavian venous thrombosis (88 limbs) and 26 normal volunteers (52 limbs). Venograms were obtained in 18 patients (22 limbs) and correlated in all cases with the previous IPG interpretation. The test procedure and interpretation criteria for the noninvasive detection of upper extremity deep venous thrombosis are similar to those previously developed for the lower extremities, but with more emphasis on comparison with the contralateral limb. Vascular laboratories performing IPG for lower extremity DVT should be able to employ this test for the detection of upper extremity venous thrombosis as well.

Adolescent↗
PubMed1983

Transducers for ultrasonic limb plethysmography.

Shifts in blood content of tissues cause dimension changes which can be measured with an ultrasonic dimension gauge. We have previously described the construction of a limb plethysmograph which uses this principle. Although other workers have described the construction of ultrasonic dimension gauge transducers intended for use inside animals, these transducers are not ideal for plethysmographic application. In this report we describe the design, construction, and performance characteristics of transducers suitable for limb plethysmography. Good signal quality is obtained with minimum care in transducer placement. These transducers incorporate a rugged external housing which provides for simple attachment to the calf by use of double-sided adhesive collars.

Humans↗
PubMed1980

[Assessment of respiratory function by body plethysmography (author's transl)].

The assessment of respiratory function by means of body plethysmography is particulary important in obstructive respiratory disorders. The conventional interpretation considered the bronchial resistance to be a relation between the alpha- and beta-slopes. The individual examination of these factors under work stress, histamine challenge and hexoprenaline broncholysis shows that the changes in the resistance will mainly be dependent on the beta-slope, even in the presence of a paradox response of the alpha-slope and, therefore, a reverse change in the intrathoracic gas volume. Therefore the beta-slope alone can be used to give satisfactory information about the bronchial resistance as an alternative method or, in the case of any difficulty in getting an airway shutter slope, for example, in paediatrics.

Aerosols↗
PubMed1982

Technique of venous impedance plethysmography for quantification of venous reflux.

A study was conducted applying a technique of venous impedance plethysmography for the quantitation of venous reflux to a group of 20 normal persons and five patients with postphlebitic limbs. Results demonstrate a significantly higher reflux refilling rate for those patients with postphlebitic limbs compared with the refilling rate for those in the normal group. It is believed that this technique is a valuable diagnostic tool for detecting venous reflux caused by valve incompetence and that it provides an indication of progression of venous insufficiency in the patient.

Humans↗
PubMedDate not supplied

Plethysmography study and pulmonary function in well-trained adolescents.

The values of lung volumes (VC, FRC, TGV, FEV1.0, etc.) and airway resistances (Raw, Raw) were measured by the spirometry and plethysmography method in 35 physically well trained, healthy adolescents, aged 14 to 20 years, boys and girls coming from various schools from the Grenoble area. The data were correlated with body height and some also with age or weight through linear, exponential or power law relationships. All volumes increased with height (Ht), which was the best independent variable, with some preference for a linear representation. However the increase of lung volumes with height was also well reproduced by an exponential function proportional for all volumes to e0.020Ht in good agreement with recent results obtained for young children. Some significant sex differences were observed for lung volumes. Airway resistance measured by two different methods (Raw and Raw) decreased with height with some preference for a linear relationship. The mean airway resistance (Raw) obtained from a complete inspiration-expiration curve while the subject breathed at his own spontaneous breathing rate was systematically smaller (from 0.5 to 1 cmH2O/l/s) than Raw measured by a technique similar to the panting method. No sex differences for airway resistances or conductances were observed. Specific airway conductance was found to be age and height independent.

Adolescent↗
PubMed1982

Measurement of systolic time intervals by electrical plethysmography: validation with invasive and noninvasive methods.

An experiment was conducted to validate the use of electrical impedance plethysmography for measuring systolic time intervals. This method is of interest in aerospace medicine since it is a noninvasive technique and very easy to use without causing discomfort to the subject. The equipment, with electrodes placed in front of the heart, gave both the first derivative of the electrical impedance variation and the E.C.G. The tracings were compared to simultaneous recordings of either the carotid pulse or blood pressures obtained by right and left catheterization. The results did not permit us to determine the right side systolic times. However, demarcated points of the plethysmogram permitted us to determine accurately the beginning of left mechanical systole and aortic opening and closure. Consequently, this method can determine the left ejection time (LPEP), the left isovolumetric contraction time (LIVCT), and the ventricular ejection time (LVET) with good accuracy.

Blood Pressure↗
PubMed1982

[Impedance plethysmography. Comparison of sensibility and specificity in recent deep venous thromboses of the lower limbs (author's transl)].

Although phlebocavography remains the ideal technique of diagnosis and reference, impedance plethysmography is a simple non-invasive technique which records variations in impedance of a limb segment through which a H.F. current is injected and with distal venous occlusion. Variations in impedance go hand in hand with variations in volume. It is thereby possible to demonstrate any obstacle to venous flow, either of an obstructive type if there is thrombosis of the major proximal collecting vessels, or of a restrictive type if there is thrombosis in the leg. The technical conditions of the examination and measurement are here fundamental and hence the value of a specially designed apparatus and multi-input abacuses in order to determine indices of emptying, filling and filling rate with simultaneous examination of both limbs. The method is selective for the diagnosis of recent deep venous thrombosis: 83% correlation between impedance and phlebography, 16% false positive and 1% false negative, reliability at the level of the thigh in 98% of cases, lesser reliability in the calf though the score can be improved and touch 94% by comparison of the two legs (Franco). Wuydin has reported a specificity of 85% and a sensitivity of 96%. This reliable, specific, objective, atraumatic, inexpensive and easily repeatable method may be used to give an overall quantification of a proximal obstructive thrombosis and define the existence of a thrombosis in the calf.

Diagnosis, Differential↗
PubMed1981

Alterations of occlusive cuff impedance plethysmography results in the obstetric patient.

Impedance plethysmography (IPG) is an attractive diagnostic method for evaluating deep vein thrombosis in the pregnant patient because it is noninvasive and it avoids x-ray or radionuclide exposure. However, the accurate diagnosis of deep venous thrombosis by IPG in pregnant patients might be altered by the normal physiologic and anatomic changes that occur during pregnancy. We evaluated 50 healthy women by IPG throughout their pregnancies and during their nonpregnant state. We found that venous capacitance during pregnancy increases 50% over venous capacitance during the non pregnant state. Most of this change occurs during early pregnancy because of a decrease in venous tone caused by rising levels of progesterone and estradiol. During the third trimester of pregnancy venous outflow is diminished compared to outflow during early pregnancy. Venous obstruction by the gravid uterus and fetal head engaging in the pelvis are factors that contribute to this finding. The IPG results in four patients with ileofemoral thrombosis and in three with postpartum pulmonary emboli are also reported. IPG may be utilized as an accurate diagnostic technique in the pregnant woman if the physiologic and anatomic alterations of pregnancy, which are reflected as significant changes in venous capacitance and outflow on IPG testing, are considered.

Adolescent↗
PubMedDate not supplied

Prazosin-induced haemodynamic modification in human hypertension. Evidence from strain-gauge plethysmography. Part II.

Three hypertensive in-patients responsive to a single oral administration of 1 mg prazosin were studied to compare the delays of drug effect on peripheral blood flow (PBF), heart rate (HR) and blood pressure (BP). Arm PBF was measured by venous occlusion strain-gauge plethysmography in a long run session (lasting at least 2 hours) every 5 - 10 minutes. HR and BP were measured accordingly, by conventional methods. The delays of the effect were compared by a cross correlation function of HR, systolic and diastolic BP versus PBF. The results show both advance and delay of HR increase as compared with PBF increase, suggesting some independent mode of action of prazosin at peripheral (vasodilation) and central (HR) level. BP decrease is instead always delayed with respect to PBF increase, by a variable amount (10 - 60 minutes) and with some difference in time response to systolic and diastolic BP, suggesting some independent feed-back loops controlling systolic and diastolic BP adjustment due to primary vasodilation effect.

Blood Pressure↗