Transcutaneous electrical neurostimulation relieves primary dysmenorrhea: A randomized, double-blind clinical study versus placebo.

INTRODUCTION: This randomized, crossover, double-blind, controlled trial evaluates the efficacy and safety of a preprogrammed transcutaneous electrical nerve stimulation (TENS) device versus placebo (SHAM) in women with primary dysmenorrhea (PD). MATERIAL: Forty women suffering from significant dysmenorrhea requiring the use of analgesics and/or non-steroidal anti-inflammatory drugs self-apply to the abdominal or lumbar region depending on the location of the pain, alternately according to randomization, the TENS device then the SHAM (dummy device) or conversely SHAM then TENS. The primary endpoint compares the evolution of pain intensity before and after application of TENS and SHAM. The speed of action, the persistence of the analgesic effect and the therapeutic savings are also evaluated. Adverse events (AEs) are collected. RESULTS: A statistically and clinically significant decrease in the pain of 53% (P<0.0001) is observed during the first 2 applications of TENS versus no analgesic effect (-5%, P=0.318) with SHAM. Over all 197 applications of TENS, the reduction of menstrual pain intensity by more than half is confirmed. The rapid relief, less than 20 minutes in 74% of cases, lasts on average more than 7 hours. A difference in analgesic consumption of -93% is observed in favor of TENS (P<0.01). Seven participants reported 10 non-serious AEs, 2 of which were possibly related to TENS. CONCLUSION: The TENS device tested represents a well-tolerated, rapidly and lastingly effective non-pharmacological analgesic solution, capable of replacing or being combined with analgesics in the management of PD.

InGaN µLEDs integrated onto colloidal quantum dot functionalized ultra-thin glass.

Red-, orange-, and green-emitting integrated optoelectronic sources are demonstrated by transfer printing blue InGaN µLEDs onto ultra-thin glass platforms functionally enhanced with II-VI colloidal quantum dots (CQDs). The forward optical power conversion efficiency of these heterogeneously integrated devices is, respectively, 9%, 15%, and 14% for a blue light absorption over 95%. The sources are demonstrated in an orthogonal frequency division multiplexed (OFDM) visible light communication link reaching respective data transmission rates of 46 Mbps, 44 Mbps and 61 Mbps.

RGB and white-emitting organic lasers on flexible glass.

Two formats of multiwavelength red, green and blue (RGB) laser on mechanically-flexible glass are demonstrated. In both cases, three all-organic, vertically-emitting distributed feedback (DFB) lasers are assembled onto a common ultra-thin glass membrane substrate and fully encapsulated by a thin polymer overlayer and an additional 50 µm-thick glass membrane in order to improve the performance. The first device format has the three DFB lasers sitting next to each other on the glass substrate. The DFB lasers are simultaneously excited by a single overlapping optical pump, emitting spatially separated red, green and blue laser output with individual thresholds of, respectively, 28 µJ/cm(2), 11 µJ/cm(2) and 32 µJ/cm(2) (for 5 ns pump pulses). The second device format has the three DFB lasers, respectively the red, green and blue laser, vertically stacked onto the flexible glass. This device format emits a white laser output for an optical pump fluence above 42 µJ/cm(2).

Surgical management of Moyamoya disease and syndrome: Current concepts and personal experience.

In this focus, we review, in the light of the recent literature, the modalities and indications of surgical cerebral revascularization for Moyamoya (MM) disease or syndrome. We also report our experience in the surgical management of adult MM. In symptomatic forms, with presence of severe disturbances of perfusion or cerebrovascular reactivity on multimodal imaging work-up, the risks of recurrent ischemic or hemorrhagic stroke is high (respectively 10-13%/yr and 2-7%/yr). The objective of treatment is to augment cerebral perfusion (in ischemic forms) or to reduce lenticulo-striate neovessel overload (in hemorrhagic forms), by initiating the development of a cortical neovascularization and/or by directly increasing cerebral blood flow. The risk of immediate postoperative death or stroke is similar between indirect and direct or combined techniques and respectively 0-0.5% and 3-6%, provided a strict perioperative anesthetic management is applied (normocapnia, normoxia and controlled hypertension). Indirect techniques (i.e. encephalo-duro-arterio-myo-periosteo-synangiosis or multiple burr-holes) are technically easy, allow wide cortical revascularization and are very efficient in children: absence of clinical recurrence in more than 95% of cases and presence of a good neovascularization in 83%. However, their effect is delayed for several months, the impact on the hemorrhagic risk is moderate and the global response is uncertain in adults. Direct (superficial temporal artery to middle cerebral artery bypass) or combined techniques improve cerebral blood flow immediately and significantly. They are associated with a higher rate of stroke-free survival at 5 years (95% vs 85%). A recent randomized study has proven that they could reduce the hemorrhagic risk by 2- to 3-fold in comparison with conservative treatment alone. However, their feasibility in children is limited by the very small size of vessels. We present also our results in the surgical management of 12 adult MM patients (mean age 41.3, sex ratio=1) operated between 2009 and 2014 (14 revascularization procedures: EDAMS 2, multiple burr-holes 1, combined revascularization procedures 11). MM types according to clinical presentation were the following: ischemic 8, hemorrhagic 2, combined 2. All patients were recently symptomatic, with recurrent ischemic/hemorrhagic events (2/3) or crescendo neurological deficit (1/3) in association with severe alterations of cerebral blood flow. Mean clinical and radiological follow-up was 22 months. Postoperative mRS at 6 months was improved or stable in 92%. None of the patients suffered recurring stroke. In conclusion, surgical treatment should be discussed quickly in symptomatic forms of MM (progressive or recurring) because of their poor outcome. Indirect techniques are favored in pediatric patients due to their simplicity and good clinical results. Direct, or preferentially combined techniques would be more effective in adult patients to prevent the recurrence of ischemic or hemorrhagic stroke.

Diode-pumped, mechanically-flexible polymer DFB laser encapsulated by glass membranes.

A diode-pumped, mechanically-flexible organic distributed-feedback laser that is fully encapsulated with ultra-thin glass is reported. The organic laser is excited by 450 nm laser diode and emits at 537 nm with an oscillation threshold of 290 W/cm². The encapsulation format of the device results in a photostability that is improved by two orders of magnitude compared to a non-encapsulated reference device while maintaining mechanical flexibility thanks to an overall device thickness below 105 µm. The laser is also wavelength-tunable between 535 nm and 545 nm by bending the ultra-thin glass structure.

Nanosecond colloidal quantum dot lasers for sensing.

Low-threshold, gain switched colloidal quantum dot (CQD) distributed-feedback lasers operating in the nanosecond regime are reported and proposed for sensing applications for the first time to the authors' knowledge. The lasers are based on a mechanically-flexible polymeric, second order grating structure overcoated with a thin-film of CQD/PMMA composite. The threshold fluence of the resulting lasers is as low as 0.5 mJ/cm² for a 610 nm emission and the typical linewidth is below 0.3 nm. The emission wavelength of the lasers can be set at the design stage and laser operation between 605 nm and 616 nm, while using the exact same CQD gain material, is shown. In addition, the potential of such CQD lasers for refractive index sensing in solution is demonstrated by immersion in water.

[Prenatal spontaneous closure of gastroschisis: a paradoxal evolution with poor outcome]. / Disparition prénatale spontanée d'un laparoschisis: une évolution de mauvais pronostic.

Usually considered as an isolated malformation carrying a rather good postnatal prognosis, gastroschisis may however occasionally bear an unfavourable outcome despite reassuring ultrasound follow-up. We report on the case of a fetus with gastroschisis diagnosed at 13 weeks of gestation followed by a progressive bowel absorption and closure of the abdominal defect at 24 weeks, associated with a 10 to 15mm intra-abdominal bowel tract dilatation. At birth, the infant did not show any recognizable ventral wall defect or scar. Surgical exploration was decided due to the presence of a high level bowel tract occlusion associated with a dilated proximal jejunum on standard abdominal X-ray radiograph. Long-segment atresia of the midintestine without any possible surgical option was observed. The infant died at day 5.

[Abnormal origin of the left coronary artery from the pulmonary artery: a retrospective study of 36 cases]. / Anomalie de naissance de la coronaire gauche à partir de l'artère pulmonaire: étude rétrospective de 36 patients.

The aim of this study was to show the evolution of diagnostic techniques revealing an abnormal origin of the left coronary artery and present the follow-up results of patients operated for this malformation at different ages. This retrospective study includes 36 children or adults, with a mean age at the moment of of 28 months old, ranging from 7 days to 39 years. In 9% of cases, patients were asymptomatic. Before 1990, 81% of children had a cardiac catheterization, versus 25% after. Indeed, echocardiography with color Doppler enabled the diagnosis of abnormal origin of the left coronary artery in 70% of cases. The pre-operative mortality is at 21% (12.5% after 1990). Twenty-three patients had surgery: left coronary artery reimplantation (n=16), bypass (n=5), at mean of 44 months old for the entire series, but 21 months old after 1990. The follow-up was clinical, ECG and radiographic and echocardiographic after 1975; when possible an exercise test, cardiac nuclear imaging and more recently coronary CT scan and MRI have been performed. In conclusion, children are operated earlier and the follow-up should focus on the detection of occlusion of the re-implanted left coronary artery by echocardiography, with or without stress, exercise test, cardiac nuclear imaging, MRI and sometimes, coronary angiography.

Fluorene-containing tetraphenylethylene molecules as lasing materials.

A series of star-shaped oligofluorene molecules, each containing a TPE core, have been specifically designed and produced to show effective aggregation-induced emission (AIE). Each molecule differs either in the number of fluorene units within the arms (e.g., 1 or 4, compounds 4 and 5), or the terminal group positioned at the end of each arm (e.g., H, TMS, or TPA, compounds 4, 6, and 7). Although they are all poor emitters in solution phase they become efficient yellow-green luminogens in the condensed state. Their AIE properties were investigated in THF/H2O mixtures, with each molecule exhibiting a clear emission enhancement at specific water contents. An all-organic distributed feedback (DFB) laser was fabricated using compound 4 as the gain material and exhibited an average threshold energy fluence of 60 ± 6 µJ/cm2 and emission in the green region. Furthermore, piezofluorochromism studies on a thin film of this material displayed a linear dependence of the amplified spontaneous emission (ASE) peak position on applied pressure, indicating potential applications as lasing-based pressure sensors. © 2016 The Authors. Journal of Polymer Science Part A: Polymer Chemistry Published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 734-746.

[Vulvoperineoplasty for vulvar pain in the posterior fourchette (15 cases)]. / Vulvopérinéoplastie pour douleurs vulvaires localisées à la fourchette (15 cas).

BACKGROUND: Vulvar pain is a common presenting complaint in dermatology consultations arising from numerous possible causes. Where such pain is mechanical, resulting from stretching of the vulva, particularly during sexual intercourse, the patient should be checked for anatomical features that could account for the pain, localised anatomical adhesions or sclerosis of the fourchette, and amenable to treatment by vulvoperineoplasty. PATIENTS AND METHODS: A retrospective study of all patients undergoing vulvoperineoplasty for vulvar pain in the fourchette was carried out between 1.1.1993 and 1.1.2003. RESULTS: Fifteen successive patients were included in the study. The mean rate of sexual intercourse doubled between the pre-operative period and the post-operative period, rising from 5 (0 to 30) to 9.8 (3 to 30). Mean pain intensity during intercourse on a scale of 1 to 10 fell from 7.6 (5 to 9) before surgery to 1.6 (0 to 5) after surgery. None of the patients experienced any sequelae. All patients except one (who was no longer sexually active), expressed willingness to undergo vulvoperineoplasty again if necessary. DISCUSSION: Vulvoperineoplasty is a simple procedure and proved useful for female patients presenting vulvar pain and adhesions or sclerosis of the fourchette.

Anterior chordal transection impairs not only regional left ventricular function but also regional right ventricular function in mitral regurgitation.

BACKGROUND: Preservation of annuloventricular continuity through the chordae tendinae aims to maintain left ventricular (LV) function and thus improve postoperative prognosis. This study was designed to prospectively investigate the effect of anterior chordal transection on global and regional LV and right ventricular (RV) function in mitral regurgitation (MR). METHODS AND RESULTS: Sixty-five patients with severe MR underwent radionuclide angiography before and after either mitral valve (MV) repair (42 patients) or replacement with anterior chordal transection (23 patients). LV and RV ejection fractions (EF) were determined at rest. Both ventricles were divided into 9 regions to analyze regional EF and the effect of anteromedial translation related to surgery. After surgery there was a significant decrease in LVEF (P=0.038) and an increase in RVEF (P=0.036). However, LVEF did not change after MV repair (63.8+/-9.9% to 62.6+/-10.3%), whereas RVEF improved (40.7+/-10.1% to 44.5+/-8.1%, P=0.027). In contrast, LVEF decreased after MV replacement (61.7+/-10.1% to 57.2+/-9.9%, P=0.03), and RVEF was unchanged (40.9+/-10.9% to 41.3+/-9.1%). LVEF 4 and 5, in the area of anterior papillary muscle insertion, were impaired after MV replacement compared with MV repair (region 4, 77.6+/-16.7% versus 87.7+/-10.8%, P=0.005, and region 5, 73.9+/-19.3% versus 89.9+/-13.1%, P<0.001). Moreover, anterior chordal transection led to a significant impairment in the apicoseptal region of the RV (RVEF 4, 50.3+/-15.6% versus 59.3+/-13.8%, P=0.02). CONCLUSIONS: Anterior chordal transection during MV replacement for MR impairs not only regional LV function but also regional RV function.

Effect of mitral valve surgery on exercise capacity, ventricular ejection fraction and neurohormonal activation in patients with severe mitral regurgitation.

OBJECTIVES: The purpose of this study was to prospectively investigate the effects of surgical correction of mitral regurgitation (MR) on exercise performance, cardiac function and neurohormonal activation. BACKGROUND: Little is known about the effect of surgical correction of MR on functional status or on neurohormonal activation. METHODS: Cardiopulmonary exercise test, radionuclide angiography and blood samples for assessment of neurohormonal status were obtained in 40 patients with nonischemic MR before and within one year (216+/-80 days) after surgery. Twenty-four patients underwent mitral valve repair (MVr), and 16 underwent valve replacement (VR) with anterior chordal transection. RESULTS: Despite an improvement in New York Heart Association functional class, exercise performance did not change (peak oxygen consumption: 19.3+/-6.1 to 18.5+/-5.6 ml/kg/min, percentage of maximal predicted oxygen consumption: 79.5+/-18.2% to 76.8+/-16.9%). After surgery, left ventricular (LV) ejection fraction (EF) decreased (64.2+/-10.3% to 59.9+/-11.4%, p = 0.003) while right ventricular (RV) EF increased (41.4+/-9.6% to 44.7+/-9.5%, p = 0.03). Left ventricular EF did not change after MVr (64.3+/-11.5% to 61.5+/-12.2%), but RVEF improved (40.4+/-9.2% to 46.0+/-10.0%, p = 0.02). In contrast, VR was associated with an impairment of LV function in the apicolateral area and a decrease in LVEF (64.1+/-8.5% to 57.4+/-10.0%, p = 0.01), whereas RVEF did not change (42.9+/-10.3% to 42.8+/-8.6%). Moreover, there was only a slight decrease in neurohormonal activation after surgery. CONCLUSIONS: Despite an improvement in symptomatic status, exercise performance was not improved seven months after either MVr or VR for MR, and neurohormonal activation persisted. Compared with MVr, VR resulted in a significant impairment of cardiac function in this study.

[Usefulness of procalcitonin for the diagnosis of acute pyelonephritis in children]. / Apport du dosage de la procalcitonine pour le diagnostic de pyélonéphrite aiguë de l'enfant.

BACKGROUND: Acute pyelonephritis can induce parenchymal scarring. The aim of this study was to evaluate the usefulness of procalcitonin (PCT) to predict renal involvement in febrile children with urinary tract infection (UTI). METHODS: In a prospective study serum PCT was measured and compared with others commonly used inflammatory markers in children admitted to the emergency unit with acute pyelonephritis. Renal parenchymal involvement was assessed by a (99 m)Tc-labeled dimercaptosuccinic acid (DMSA) renal scar performed in the first 3 days after the admission. RESULTS: Among 42 enrolled patients, 19 (45%) had acute renal involvement (Group A) ; 23 (55%) (Group B) had normal DMSA scan (n = 16), or old scarring (n = 4) or various anomalies related to uropathy (n = 3). In group A, the mean PCT level was significantly higher than in the group B (5.4 ng/ml, vs 0.4 ng /ml, p < 10(-5)). In these 2 groups, mean C reactive protein (CRP) levels were 99.1 mg/l and 44.6 mg/l respectively (p < 0.001). For a level of serum PCT > or = 0.5 ng/ml, the sensitivity and specificity to predict the renal involvement were 100% and 87% respectively; for a level> or= 20 mg/l CRP had a sensitivity of 94% but a specificity of 30%. CONCLUSION: Serum PCT levels were significantly increased in febrile children with UTI when acute renal parenchymal involvement was present. PCT seems a better marker than CRP for the prediction of patients at risk of renal lesions.

Brain metabolic abnormalities during gait with freezing in Parkinson's disease.

INTRODUCTION: Freezing of gait (FoG) is a debilitating gait disorder in Parkinson's disease (PD). In advanced PD patients with FoG, the supraspinal locomotor network may be dysregulated (relative to similar patients without FoG) during gait. Here, we sought to characterize the metabolism of locomotor networks involved in FoG. METHODS: Twenty-two PD patients (11 with off-drug FoG and 11 without) each underwent two [(18)F]-fluorodeoxyglucose PET brain scans in the off-drug state: one at rest and another during radiotracer uptake while performing a standardized gait trajectory that incorporated the usual triggers for FoG. RESULTS: For the 11 freezers, FoG was present for 39% (± 23%) of the time during the gait trajectory. The FoG-associated abnormalities were characterized by (i) hypometabolism in frontal regions (the associative premotor, temporopolar and orbitofrontal areas, i.e. Brodmann areas 6 and 8), (ii) hypermetabolism in the paracentral lobule (Brodmann area 5), and (iii) deregulation of the basal ganglia output (the globus pallidus and the mesencephalic locomotor region). CONCLUSION: FoG during a real gait task was associated with impaired frontoparietal cortical activation, as characterized by abnormally low metabolic activity of the premotor area (involved in the indirect locomotor pathway) and abnormally high metabolic activity of the parietal area (reflecting the harmful effect of external cueing).

Fatty acid metabolism, pharmacological nutrients and hypertension.

The purpose of the present study was to investigate the effect of a concentrated preparation (EPA 30) containing eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) on the limiting desaturation steps of the polyunsaturated fatty acid biosynthesis in spontaneously hypertensive rats (SHR). Adult SHR were divided into two groups: one group received a standard diet, and the experimental group the standard diet including 0.8% of EPA30 for 9 weeks. Blood pressure was measured at the end of the diets. The desaturase activities and fatty acid composition were determined in isolated hepatocytes. The blood pressure did not decrease in the experimental group. The desaturated products of the n-6 family (gamma-linolenic acid, 18:3 n-6 and arachidonic acid, 20:4 n-6) were lowered in the EPA30 group, when their respective substrates (18:2 n-6 and 20:3 n-6) were increased. EPA and DHA were higher in the experimental group delta 6 n-3, delta 6 n-6 and delta 5 n-6 desaturase activities were depressed approximately 20% in the EPA30 group. EPA30 being an active nutrient on the EFAs cascade, increasing the level of PG3 precursors and decreasing the level of PG2 precursors, favourable conditions have been established to reduce hypertension. The underlying mechanism related to the regulation of desaturase activities by these fatty nutrients remains to be elucidated.

Liver microsomal membrane fluidity and microsomal desaturase activities in adult spontaneously hypertensive rats.

OBJECTIVE: The purpose of the present study was to investigate liver microsomal membrane fluidity simultaneously with membrane fatty acid composition and desaturase activities in spontaneously hypertensive rats (SHR). DESIGN AND METHODS: The membrane fluidity was determined, after electron spin resonance (ESR) measurement, in SHR compared with normotensive Wistar-Kyoto (WKY) rats, by calculating the order parameter S from ESR spectra of 5-nitroxide stearate and 10-nitroxide stearate, used as spin-labelled fatty acids. Desaturase activities were measured by incubating SHR and WKY rat liver microsomes with [14C]-radiolabeled fatty acids as substrates for desaturation reactions. The fatty acid composition of liver microsomal membranes was determined by gas-liquid chromatography. RESULTS: Whereas no significant difference between S of 5-nitroxide stearate was observed for SHR and WKY rats, S of 10-nitroxide stearate was significantly lower in SHR than it was in WKY rat microsomal membrane, indicating that the core microsomal membrane fluidity was higher in SHR. Significant differences between fatty acid compositions were observed for SHR and WKY rat microsomal membranes. Delta9 and n-6 delta6 microsomal desaturase activities were significantly lower in SHR. CONCLUSION: These results suggest that the higher liver core microsomal membrane fluidity observed in SHR might be dependent on the increased proportion of mono-unsaturated fatty acids. Such observed modifications and the alterations in delta9 and n-6 delta6 desaturase activities suggest that an impaired polyunsaturated fatty acid biosynthesis is related to changes in microsomal membrane fluidity in hypertension.

Intraoperative radionuclear 125I-labeled metaiodobenzylguanidine scanning of pheochromocytomas and metastases.

We developed a technique to assess the feasibility of intraoperative radionuclear detection of pheochromocytomas and their metastases. Thirteen patients were entered into the study: five control subjects with nonchromaffin adrenal tumors, eight with pheochromocytomas, and one of these patients showing bone metastasis. Each subject received thyroid blockade and an intravenous injection of 500 microCi (37 megabecquerels) 125I-labeled metaiodobenzylguanidine (MIBG) 3 days before surgery. In the five control subjects, adrenal tumor uptake never exceeded the liver or spleen uptake. One patient with a negative preoperative MIBG scan demonstrated no intraoperative uptake. Five patients with pheochromocytoma had positive preoperative scans and in one other patient preoperative scanning was not done. In each of these six patients intraoperative count ratio of pheochromocytoma/liver from 14:2 to 250:16 and pheochromocytoma/contralateral adrenal ratio from 60:1.5 to 60:16 was demonstrated. An intraoperative scan in one of these patients detected two small metastatic tumor deposits previously overlooked by the surgeon after removing a larger mass that had been localized by a preoperative 131I-MIBG scan. A negative preoperative scan in one patient was followed by an intraoperative scan demonstrating a bone metastasis with a ratio of metastasis/normal bone of 10:0.5. Specimen studies demonstrated a significant MIBG uptake ratio of tumor/plasma ranging from 95 to 667 (average 404 +/- 242) greater than in control subjects (average 25 +/- 41); in the patient with metastasis the uptake ratio of metastasis/normal bone reached 98.4. We conclude that intraoperative 125I-MIBG scanning might detect pheochromocytoma deposits overlooked by preoperative 131I-MIBG scans.

Inhaled NO preadministration modulates local and remote ischemia-reperfusion organ injury in a rat model.

Inhaled nitric oxide (iNO) has been shown to have a protective effect in lung ischemia-reperfusion (I/R)-induced injuries. We studied the role of iNO (10 parts/million for 4 h) administered before I/R. In an isolated perfused lung preparation, iNO decreased the extravascular albumin accumulation from 2,059 +/- 522 to 615 +/- 105 microl and prevented the increase in lung wet-to-dry weight ratio. To study the mechanisms of this prevention, we evaluated the role of nitric oxide (NO) transport and lung exposure with matched experiments by using either lungs or blood of animals exposed to iNO and blood or lungs of naive animals. iNO-exposed blood with naive lungs did not limit the extravascular albumin accumulation (2,561 +/- 397 microl), but iNO-exposed lungs showed a leak not significantly different from the group in which both lungs and blood were iNO exposed (855 +/- 224 vs. 615 +/- 105 microl). An improvement in heart I/R left ventricular developed pressure in the animals exposed to iNO showed that blood-transported NO was, however, sufficient to trigger remote organ endothelium and reduce the consequences of a delayed injury. In conclusion, preventive iNO reduces the consequences of lung I/R injuries by a mechanism based on tissue or endothelium triggering.

A miniature cesium iodide-photodiode detector for ambulatory monitoring of left ventricular function.

The physical characteristics of a portable nonimaging scintillation probe system for continuous ambulatory monitoring of the left ventricular function are described. The detector of the equilibrium radionuclide labeled blood pool is a single cesium iodide (CsI) crystal coupled to a silicium photodiode and interfaced to a microcomputer. The spatial properties of this small CsI crystal (1 x 1 x 1 cm3) were evaluated with various single-hole collimators. Linearity was studied in nonattenuating medium. Saturation began at 3000 cps, count loss was 10% at 4000 cps, maximal count rate was 24,000 cps. In attenuating medium, isocount curve of 5% of the maximal count rate was 100 mm deep and 160 mm wide. The most appropriate tested lead collimator to record the global ejection fraction of the left ventricle was a disc-shaped (thickness 5 mm, diameter 41 mm) single-hole (proximal aperture 8 mm, distal aperture 18 mm) collimator. Sensitivity was similar to the sensitivity of a sodium iodide nuclear probe. The detection performance appeared comparable to other available detector systems. Our results indicate that such a CsI-photodiode probe is a promising candidate for left ventricular function monitoring. The application to an ambulatory multicrystal detector system is presented and discussed.

RF-transmitted CsI radio-isotopic ambulatory recorder for left ventricular ejection fraction monitoring.

We have developed a CsI multidetector probe in order to produce a nuclear ambulatory recorder to study simultaneously cardiac electric activity and the left ventricular ejection fraction. To make the device lighter, the electronics were designed with surface-mounted technology, and a serial data RF transmission system was used. The data are processed on a real-time basis using a portable microcomputer. Unlike other commercially available devices, this monitor avoids the problems of volume, weight, recording time capacity and slow off-line data processing. Our device permits global and regional analysis of the ejection fraction for a moderate manufacturing cost. It is intended primarily for ambulatory use and can easily be adapted to perform a monitoring function. The first tests on patients conducted using the prototype demonstrate the technical reliability and satisfactory operation of the device.