Smart Detecting and Versatile Wearable Electrical Sensing Mediums for Healthcare.

A rapidly expanding global population and a sizeable portion of it that is aging are the main causes of the significant increase in healthcare costs. Healthcare in terms of monitoring systems is undergoing radical changes, making it possible to gauge or monitor the health conditions of people constantly, while also removing some minor possibilities of going to the hospital. The development of automated devices that are either attached to organs or the skin, continually monitoring human activity, has been made feasible by advancements in sensor technologies, embedded systems, wireless communication technologies, nanotechnologies, and miniaturization being ultra-thin, lightweight, highly flexible, and stretchable. Wearable sensors track physiological signs together with other symptoms such as respiration, pulse, and gait pattern, etc., to spot unusual or unexpected events. Help may therefore be provided when it is required. In this study, wearable sensor-based activity-monitoring systems for people are reviewed, along with the problems that need to be overcome. In this review, we have shown smart detecting and versatile wearable electrical sensing mediums in healthcare. We have compiled piezoelectric-, electrostatic-, and thermoelectric-based wearable sensors and their working mechanisms, along with their principles, while keeping in view the different medical and healthcare conditions and a discussion on the application of these biosensors in human health. A comparison is also made between the three types of wearable energy-harvesting sensors: piezoelectric-, electrostatic-, and thermoelectric-based on their output performance. Finally, we provide a future outlook on the current challenges and opportunities.

How Far Can the Red Palm Weevil (Coleoptera: Curculionidae) Fly?: Computerized Flight Mill Studies With Field-Captured Weevils.

Adult Rhynchophorus ferrugineus (Olivier) captured in pheromone-baited traps in commercial date palm orchards in the Al Ahsaa Directorate, Kingdom of Saudi Arabia, were used in computerized flight mill studies to determine the flight characteristics of this highly invasive and destructive palm pest. Flight mill studies were run at three different time periods, winter (December), spring (March), and summer (May). Of the 192 weevils tethered to flight mills ∼30% failed to fly > 1 km. Of those weevils flying > 1 km (n = 139), 55% flew > 10 km, and of these flyers 5% flew > 50 km in 24 h. Flying weevils exhibited an average weight loss of 20-30% and nonflying control weevils lost ∼9-13% body weight in 24 h. Male and female weevils flying in summer (average laboratory temperature was ∼27°C) flew the longest average distances (∼25-35 km), exhibited highest weight reductions (∼30%), and greatest mortality rates (∼80%). Consequently, time of year not weevil sex or color morph had a consistent and significant effect on flight activity, weight loss, and survivorship rates. Flight activity was predominantly diurnal commencing around 5:00 a.m. and peaking between 9-11:00 a.m. before tapering off. The distribution of flight distances combined across season and sex was mesokurtic (i.e., normally distributed).

Optimized multi-frequency nonlinear broadband piezoelectric energy harvester designs.

Many electrical devices can be powered and operated by harvesting the wasted energy of the surroundings. This research aims to overcome the challenges of output power with a sharp peak, small bandwidth, and the huge dimensions of the piezoelectric energy harvesters relative to the output power. The aforementioned challenges motivated us to investigate the effect of nonlinearity in the shape (tapered and straight cross-section area) as well as the fixation method (the number of fastened ends) to determine the optimal design with high output power and wide working frequency. This research proposes a novel piezoelectric energy harvester array, where each beam is made up of three fixed beams that are joined together by a center mass. The proposed design produces an output power of 35 mW between 25 and 40 Hz. The output power of the proposed design is 3.24 times more than the conventional designs. The recommended approach is simulated utilizing finite element analysis FEA. Analytical and experimental methods validate the proposed FEA, which exhibits excellent agreement.

Environmental and mineralogical studies on the stream sediments of Baltim-El Burullus coastal plain, North Delta, Egypt.

This work is mainly concerned with the effect of anthropogenic activities and natural radioactivity due to the presence of highly radioactive black sand spots, factory construction, and shipping, in addition to other activities like agriculture on human beings. Forty samples were collected along Baltim-El Burullus coastal plain to detect the effect of these problems and determine the suggested solutions. The black sand of the Baltim-El Burullus coastal plain exhibits a considerable amount of economically heavy minerals, their ratio relative to the bulk composition in the investigated samples ranges from 3.18 to 10.5% with an average of 5.45%. The most important of them are magnetite, ilmenite, rutile, leucoxene, garnet, zircon and monazite. The existence of some radioactive-bearing accessory mineral deposits like zircon and monazite led to measuring the naturally occurring radionuclides 226Ra, 232Th and 40K to evaluate the excess lifetime cancer risk (ELCR). The results showed that these concentrations are 19.1 ± 9.73, 14.7 ± 9.53 and 211 ± 71.34 Bq kg-1 were lower than the corresponding reported worldwide average of 35, 45, and 412 Bq kg-1 for each radionuclide (226Ra, 232Th, and 40 K). The gamma hazard indices such as absorbed dose rate (Dair), the annual effective dose (AED), and excess lifetime cancer risk (ELCR) factor were computed in the investigated sediments and all the results were found (Dair = 26.4 nGy h-1, AED = 0.03 mSv year-1, ELCR = 0.0001) to be lower than the values suggested by the United Nations Scientific Committee on the effect of Atomic Research (59 nGy h-1, 0.07 mSv year-1 and 0.0029 for Dair, AED and ELCR, respectively). The study suggests that the black sand is safe to use in various infrastructure applications at Baltim-El Burullus coastal plain. The levels of radioactivity are not high enough to pose a risk to human health.

Ventilation practices in the neonatal intensive care units in Saudi Arabia, survey of the utilization of volume-targeted ventilation among practicing neonatologists.

OBJECTIVE: To assess the current practice in using volume-targeted ventilation among neonatologists working at the Neonatal Intensive Care Units (NICU) of Saudi Arabia. METHODS: The questionnaire was provided electronically to 153 practicing Neonatologists working in 39 NICUs. The survey's results were received and statistically analyzed. RESULTS: One hundred nineteen (119) responses were received with, a 78% response rate. Volume Targeted Ventilation (VTV) was used routinely by 67.2%, whereas 21.8% still use only pressure control (PC)/pressure limited (PL) mode. During the acute phase of ventilation support, Assist Control was the most popular synchronized mode, whereas Synchronized Intermittent Mandatory Ventilation (SIMV) with pressure support (PS) or PSV were the two most common modes during the weaning phase, 31.8%, and 31% respectively. The majority of the neonatologists used a tidal volume of 4 ml/kg as the lowest and 6 ml/kg as the highest. The major reasons for not implementing VTV were the limited availability of ventilator devices that have an option of VTV, followed by lack of experience. CONCLUSION: VTV is the predominant ventilation practice approach among neonatologists working in the KSA. Limited availability and lack of experience in using are the main challenges. Efforts to equip NICUs with the most advanced ventilation technology, enhance practitioners' experience and sufficient training in its use are warranted.

Genetic Algorithm Optimization of Rainfall Impact Force Piezoelectric Sensing Device, Analytical and Finite Element Investigation.

In this paper, rainfall droplet impact force is transformed into a measurable voltage signal output via the piezoelectric material direct effect utilized for sensing purposes. The motivating sensor is utilized to measure the peak impact forces of rainfall droplets for further analysis and processing. Constructing a sense for the impact force of rainfall droplets has great implications in many real-life applications that can provide vital information regarding the amplifications of the impact force of rainfall on soil erosion, and the impact on small creatures and plants, etc. The rainfall droplet is set to collide on a very thin aluminum plate with negligible mass that can be presented geometrically as an extended segment of the proposed sensing device. The proposed sensing device is composed of a bimorph simply supported composite-piezoelectric beam that buckles due to the effect of the rain droplets' vertical impact force. The proposed device is designed for optimal performance in terms of the amount of voltage that can be measured. This is accomplished by having the first critical buckling load of the device as less than the impact force of the rainfall droplet. Accordingly, the well-known genetic algorithm (GA) automated optimization technique is utilized in this paper to enhance the measured voltage signal. A proof mass is added to the middle of the beam to amplify the magnitude of the measured voltage signal. The voltage signal is intended to be transferred to the PC via a data acquisition system. The rainfall droplets' peak impact forces are obtained analytically due to the nonlinear behavior of the beam using the Euler-Bernoulli thin beams assumptions. The FE model using COMSOL 6.0 Multiphysics commercial software is used to verify the analytical results.

Modeling a semi-optimal deceleration of a rigid body rotational motion in a resisting medium.

This paper studies the shortest time of slowing rotation of a free dynamically asymmetric rigid body (RB), analogous to Euler's case. This body is influenced by a rotatory moment of a tiny control torque with closer coefficients but not equal, a gyrostatic moment (GM) due to the presence of three rotors, and in the presence of a modest slowing viscous friction torque. Therefore, this problem can be regarded as a semi-optimal one. The controlling optimal decelerating law for the rotation of the body is constructed. The trajectories that are quasi-stationary are examined. The obtained new results are displayed to identify the positive impact of the GM. The dimensionless form of the regulating system of motion is obtained. The functions of kinetic energy and angular momentum besides the square module are drawn for various values of the GM's projections on the body's principal axes of inertia. The effect of control torques on the body's motion is investigated in a case of small perturbation, and the achieved results are compared with the unperturbed one. For the case of a lack of GM, the comparison between our results and those of the prior ones reveals a high degree of consistency, in which the deviations between them are examined. As a result, these outcomes generalized those that were acquired in previous studies. The significance of this research stems from its practical applications, particularly in the applications of gyroscopic theory to maintain the stability and determine the orientation of aircraft and undersea vehicles.

Sudden Vision Loss Secondary to Optic Nerve Infiltration as a Presenting Symptom of Metastatic Lung Adenocarcinoma.

Purpose: To report a rare case of left-sided metastatic optic nerve infiltration and right-sided choroidal mass with exudative retinal detachment caused by EGFR exon 19 deletion positive non-small-cell lung adenocarcinoma that responded to targeted therapy with osimertinib (EGFR-TKI). Our patient demonstrated an excellent response with reduced size of the metastatic choroidal mass of the right orbit and improved visual acuity, in addition to systemic disease control. Case: A 66-year-old male patient with a history of diabetes mellitus, hypertension, and tobacco use presented with sudden vision loss in the left eye secondary to optic nerve infiltration and subacute vision loss in the right eye secondary to exudative retinal detachment from a choroidal metastasis. He was found to have a right lung mass, multiple metastatic pulmonary nodules, and liver and bone metastases. Biopsy from a mediastinal lymph node confirmed the diagnosis of metastatic lung adenocarcinoma. He was found to have exon 19 deletion on next-generation sequencing. We treated him with local radiation therapy to the left eye and systemic osimertinib (EGFR-TKI). Conclusion: To our knowledge, our case is the first report of a patient who initially presented with acute vision loss and was found to have metastatic retrobulbar optic nerve infiltration in one eye and metastatic choroidal lesion with exudative retinal detachment in the fellow eye secondary to lung adenocarcinoma. Due to the rarity of this condition, literature regarding effective treatment is scarce. Our patient demonstrated significant improvement in visual acuity and resolution of exudative retinal detachment in the right eye following osimertinib treatment and radiation therapy to the left eye. Further investigation into the role of tyrosine kinase inhibitors and radiation therapy in treating intraocular metastasis involving the optic nerve is needed.

Studying Acoustic Behavior of BFRP Laminated Composite in Dual-Chamber Muffler Application Using Deep Learning Algorithm.

Over the last two decades, several experimental and numerical studies have been performed in order to investigate the acoustic behavior of different muffler materials. However, there is a problem in which it is necessary to perform large, important, time-consuming calculations particularly if the muffler was made from advanced materials such as composite materials. Therefore, this work focused on developing the concept of the indirect dual-chamber muffler made from a basalt fiber reinforced polymer (BFRP) laminated composite, which is a monitoring system that uses a deep learning algorithm to predict the acoustic behavior of the muffler material in order to save effort and time on muffler design optimization. Two types of deep neural networks (DNNs) architectures are developed in Python. The first DNN is called a recurrent neural network with long short-term memory blocks (RNN-LSTM), where the other is called a convolutional neural network (CNN). First, a dual-chamber laminated composite muffler (DCLCM) model is developed in MATLAB to provide the acoustic behavior datasets of mufflers such as acoustic transmission loss (TL) and the power transmission coefficient (PTC). The model training parameters are optimized by using Bayesian genetic algorithms (BGA) optimization. The acoustic results from the proposed method are compared with available experimental results in literature, thus validating the accuracy and reliability of the proposed technique. The results indicate that the present approach is efficient and significantly reduced the time and effort to select the muffler material and optimal design, where both models CNN and RNN-LSTM achieved accuracy above 90% on the test and validation dataset. This work will reinforce the mufflers' industrials, and its design may one day be equipped with deep learning based algorithms.

Agreement of anthropometric and body composition measures predicted from 2D smartphone images and body impedance scales with criterion methods.

BACKGROUND/OBJECTIVES: Body composition and anthropometry assessment from two-dimensional smartphone images is possible through advancement of computational hardware and artificial intelligence (AI) techniques. This study established agreement of a novel smartphone assessment, compared with traditional bioelectrical impedance analysis (BIA), and criterion measures. SUBJECTS/METHODS: Body composition of 929 adults was measured using DXA (GE lunar iDXA), a foot-to-foot BIA machine (TANITA BC-313), and predictions from two-dimensional smartphone images. Anthropometry measures were also collected. Body composition and anthropometry estimates were compared via concordance coefficient correlation (CCC), equivalence testing, Bland-Altman analysis, and root mean square error (RMSE). RESULTS: 2D smartphone image predictions for percent body fat (%BF) (males: CCC = 0.90 and RMSE = 2.9, and females: CCC = 0.90 and RMSE = 2.8) reported greater agreement with DXA measures than the BIA measures (males: CCC = 0.66 and RMSE = 5.6, and females: CCC = 0.79 and RMSE = 4.6). All anthropometry 2D smartphone image predictions had a strong agreement with criterion measurements (CCC ≥ 0.84 and RMSE ≤ 3.3). Body composition and anthropometry measures predicted by the 2D smartphone images were clinically equivalent at ±2.5 and ±5.0% thresholds. BIA %BF was not equivalent at either threshold; with only female BIA fat-free mass equivalent at the ±5% threshold. CONCLUSION: Body composition predictions from 2D smartphone application images provide a promising alternative to BIA scales for in-home body composition assessment. Future research should assess the validity of this method for longitudinally tracking body composition and indicating an individual's potential risk of chronic diseases.

Agreement and reasons for disagreement between photographic and hospital biomicroscopy grading of diabetic retinopathy.

AIMS: To compare agreement level and identify reasons for disagreement between grading of mydriatic digital photographs in a diabetic retinopathy screening service and hospital eye service biomicroscopy grading. METHODS: Structured examination findings leading to automatically calculated National Screening Committee grades recorded on an electronic medical record system in the hospital eye service at the first clinic visit after diabetic retinopathy screening service referral between April 2006 and November 2007 were retrospectively compared with the grade at the screening visit that prompted referral. In cases of disagreement, screening images were reviewed. RESULTS: Data on 452 eyes (226 patients) were analysed. For retinopathy, hospital eye service slit-lamp biomicroscopy grades were: R0 (no diabetic retinopathy) in 63 eyes; R1 (background retinopathy) in 251 eyes; R2 (pre-proliferative) in 129 eyes and R3 (proliferative) in nine eyes. Diabetic retinopathy screening service grades were in agreement in 350 eyes (77.4%), showed a lower grade in 59 eyes and a higher grade in 43. Agreement was moderate (κ=0.60). The most common reason for disagreement was overgrading of R1 by clinicians. Hospital eye service biomicroscopy maculopathy grades were: M0 (no maculopathy) in 366 eyes and M1 (maculopathy) in 86 eyes. Diabetic retinopathy screening service grades were in agreement in 327 eyes (72.3%), showed a lower grading in five eyes and a higher grade in 120 eyes. Agreement was moderate (κ=0.41). The commonest cause for disagreement was clinicians failing to identify fine macular exudates. CONCLUSIONS: This study of routine clinical services demonstrates moderate agreement between non-medical grading of mydriatic digital retinal photography images and hospital slit-lamp biomicroscopy grading of patients referred with diabetic retinopathy. The majority of errors in grading were attributable to errors by hospital doctors, usually in the direction of under-grading which could be a potential source of clinical risk if treatment is delayed.

Cyanophycin-degrading bacteria in digestive tracts of mammals, birds and fish and consequences for possible applications of cyanophycin and its dipeptides in nutrition and therapy.

AIMS: To determine the susceptibility of cyanophycin granule polypeptide (CGP) to degradation by several mammalian, avian and fish gut flora. METHODS AND RESULTS: Samples of gut flora were investigated for the occurrence of bacteria capable of CGP degradation. With all samples, a complete anaerobic degradation of CGP was achieved over incubation periods of only 12-48 h at 37 degrees C. CGP-degrading bacteria were detected in all samples, and they occurred in particular high titres in caecum flora from rabbit and sheep and in the digestive tract of carp fish. A total of 62 axenic cultures were isolated. All degraded CGP aerobically, 46 of them degraded CGP also anaerobically over incubation periods ranging from 24 h to 7 days. HPLC analysis revealed that all isolates degraded CGP to its constituting dipeptides. Eight strains were identified by 16S rRNA gene sequencing and were affiliated to the genera Bacillus, Brevibacillus, Pseudomonas, Streptomyces and Micromonospora. CONCLUSIONS: These data demonstrate for the first time the occurrence of a natural niche for CGP in the digestive tracts of animals. SIGNIFICANCE AND IMPACT OF THE STUDY: The biodegradability of CGP by gut flora provides a first confirmation for the potential applications of CGP and its dipeptides in nutrition and therapy as highly bio-available sources for arginine, lysine, aspartate and possibly also other amino acids.

Pseudophakic macular edema and oral acetazolamide: an optical coherence tomography measurable, dose-related response.

PURPOSE: Although uncommon after phacoemulsification surgery, cystoid macular edema (CME) is an important cause of postoperative reduction of vision after cataract surgery. To demonstrate an optical coherence tomography (OCT) measurable, dose-related response to orally administered acetazolamide in a patient presenting with pseudophakic CME. METHODS: A 76-year-old woman with reduced vision in right eye due to cataract had uneventful phacoemulsification. Surgery was complicated by early onset endophthalmitis that was treated with intravitreal antibiotics with good visual recovery. At 6 months follow-up, she presented with further reduction of vision (0.5 LogMAR) due to CME and a central foveal thickness (CFT) of 587 microm. RESULTS: Acetazolamide treatment was started in combination with topical ketorolac. At a daily dose of 500 mg, CFT and visual acuity were 262 microm and 0.34 LogMAR, respectively. Dose reduction of acetazolamide to 250 mg/day was associated with worsening of the CFT to 335 microm. CFT was subsequently measured at 230 microm on increasing the acetazolamide dose to 500 mg/day and measured 353 microm when acetazolamide dose was halved. CFT was 478 microm when acetazolamide was ceased.CONCLUSIONS. In this report, the authors have shown a dose-related response of pseudophakic CME to oral acetazolamide. This would suggest that the clinical response to oral acetazolamide may be titrated to the extent of CME and monitored by OCT.

Assessing Genomic Selection Prediction Accuracy in a Dynamic Barley Breeding Population.

Prediction accuracy of genomic selection (GS) has been previously evaluated through simulation and cross-validation; however, validation based on progeny performance in a plant breeding program has not been investigated thoroughly. We evaluated several prediction models in a dynamic barley breeding population comprised of 647 six-row lines using four traits differing in genetic architecture and 1536 single nucleotide polymorphism (SNP) markers. The breeding lines were divided into six sets designated as one parent set and five consecutive progeny sets comprised of representative samples of breeding lines over a 5-yr period. We used these data sets to investigate the effect of model and training population composition on prediction accuracy over time. We found little difference in prediction accuracy among the models confirming prior studies that found the simplest model, random regression best linear unbiased prediction (RR-BLUP), to be accurate across a range of situations. In general, we found that using the parent set was sufficient to predict progeny sets with little to no gain in accuracy from generating larger training populations by combining the parent set with subsequent progeny sets. The prediction accuracy ranged from 0.03 to 0.99 across the four traits and five progeny sets. We explored characteristics of the training and validation populations (marker allele frequency, population structure, and linkage disequilibrium, LD) as well as characteristics of the trait (genetic architecture and heritability, H2 ). Fixation of markers associated with a trait over time was most clearly associated with reduced prediction accuracy for the mycotoxin trait DON. Higher trait H2 in the training population and simpler trait architecture were associated with greater prediction accuracy.

Prevalence and incidence of blindness and other degrees of sight impairment in patients treated for neovascular age-related macular degeneration in a well-defined region of the United Kingdom.

AIMS: This study aimed to evaluate the incidence and prevalence of blindness, sight impairment, and other visual acuity (VA) states in patients receiving ranibizumab for neovascular age-related macular degeneration (nAMD) in Gloucestershire. METHODS: Serial VA and injection data for all treatment-naive patients receiving their first intravitreal injections of ranibizumab for nAMD in the Gloucestershire National Health Service Ophthalmology department between 2008 and 2010 were extracted from an electronic medical record system. RESULTS: The prevalence of blindness (VA in the better-seeing eye ≤25 Early Treatment Diabetic Retinopathy Study (ETDRS) letters) at the time of first intravitreal injection was 0.8%, increasing to 3.5% after 3 years. The prevalence of sight impairment (VA in the better-seeing eye 26-39 ETDRS letters) increased from 4.1% at baseline to 5.5% after 3 years. The incidence of initiating ranibizumab treatment for nAMD in people aged ≥50 years in Gloucestershire was 111 people per 100 000 population in 2009, and 97 people in 2010. The incidence of patients meeting the visual criteria for blindness and sight impairment registration from treated nAMD in people aged ≥50 years in Gloucestershire was 3.5 and 9.7 people, respectively per 100 000 population in 2010. CONCLUSION: This is the first real-world study on the incidence and prevalence of eligibility for blindness and sight impairment registration in treated nAMD in the UK based on VA data. The incidence and prevalence of eligibility for certification of blindness or sight impairment in patients treated with ranibizumab for nAMD is low in Gloucestershire, with only 3.6% of the incident population progressing to blindness in 2010.

Reference values for the midluteal plasma progesterone concentration: evidence from human menopausal gonadotropin-stimulated pregnancy cycles.

OBJECTIVE: To determine reference values for the midluteal plasma progesterone concentration. DESIGN: Retrospective analysis. SETTING: Infertility clinic at an academic medical center. PATIENT(S): One hundred ninety-two infertile women who became pregnant after induction of ovulation with hMG. INTERVENTION(S): The plasma progesterone level was measured during the midluteal phase of the hMG treatment cycle. MAIN OUTCOME MEASURE(S): The midluteal plasma progesterone concentration was correlated with the outcome of the pregnancy. RESULT(S): In this cohort of 192 women in whom ovulation was induced with hMG and 5,000 IU of hCG, the mean midluteal plasma progesterone concentrations were 29.07 ng/mL, 25.85 ng/mL, 31.49 ng/mL, 41.39 ng/mL, and 28.64 ng/mL in all cycles that resulted in pregnancy, cycles that resulted in full-term singleton pregnancy, cycles that resulted in full-term multiple pregnancy, cycles that resulted in preterm pregnancy, and cycles that ended in miscarriage, respectively. There was no statistically significant difference in the progesterone concentration between the cycles that resulted in full-term pregnancy and those that ended in miscarriage, but there was a statistically significant difference between the cycles that resulted in singleton pregnancy and those that resulted in multiple pregnancy. The minimum value that was compatible with a full-term pregnancy in this cohort of women was 10.83 ng/mL. CONCLUSION(S): In a cohort of 192 women, the minimum plasma progesterone concentration on day 7 in women who attained a full-term pregnancy after induction of ovulation with 5,000 IU of hCG was 10.83 ng/mL.

Lactic acid-induced modifications in films of Eudragit RL and RS aqueous dispersions.

Eudragit RL (ERL) and RS (ERS) are polymethacrylate co-polymers, used in film coating of sustained release dosage forms, possessing some hydrophilic properties due to the presence of quaternary ammonium groups (QAG), where ERL contains more of such groups, hence more permeable, than ERS. However, because these groups ionize in solution, they undergo electrostatic interaction with negatively charged species. This phenomenon was utilized in this study to introduce modification in the film properties of ERL and ERS by interaction with lactic acid (LA). Thermal and mechanical analyses were carried out on polymeric free films. DSC showed a shift in Tg of the film while 1H NMR spectroscopy revealed a significant deshielding in the peak of QAGs protons after interaction with LA. Stress-strain test showed an increase in three mechanical parameters of the new film (containing LA): tensile strength to modulus ratio, relative surface energy and toughness index, indicating an enhancement in the mechanical stress resistance. Tablets coated with LA-containing films showed an increase in the release rate and extent and good stability upon aging, compared to those coated with the original film.

Mathematical relationships between uterine contractions, cervical dilatation, descent and rotation in spontaneous vertex deliveries.

OBJECTIVE: To determine the mathematical relationships between the strength and duration of the uterine contractions, the descent and rotation of the fetal head and the degree of cervical dilatation in 50 multiparous women with spontaneous vaginal deliveries using a simple device applied to the fetal vertex. METHOD: A simple device for monitoring the progress of labor was applied to the fetal vertex. The device allows the continuous monitoring of descent and rotation of the fetal head. The amount of descent and the degree of rotation were also determined by repeated vaginal examinations as well as the degree of cervical dilatation. The frequency of uterine contractions was also recorded on a partogram. RESULT: A good correlation was found between the amount of descent of the fetal vertex (r = 0.975) and between the degree of rotation of the fetal head (0.83) determined by both methods. Multiple regression analysis was then performed and the degree of cervical dilatation in cm at any given time during the first stage of labor was found to be equal to 2.859 + 0.583 fetal head station in (cm) + 0.1983 internal rotation in degrees -0.0493 (station x internal rotation) + 0.1599 station2 + 0.3622 uterine contractions per 10 min. A nomogram was constructed allowing the calculation of cervical dilatation for a given station of the head, degree of rotation and frequency of uterine contractions. CONCLUSION: There is a defined mathematical relationship between the degree of descent and rotation of the fetal head, the degree of cervical dilatation and the frequency of uterine contractions in multiparous women with vertex presentation. The first three variables can be continuously determined by using the described device. Incorporation of the device into a reusable fetal scalp electrode allows the dual mechanical and electronic monitoring during labor with minimal vaginal examinations.

Human red blood cell hemolysis in a turbulent shear flow: contribution of Reynolds shear stresses.

Various previous models used in studying red blood cell (RBC) hemolysis in turbulent shear flows are reviewed from a fluid dynamic point of view. The effect of turbulent shear stress (Reynolds shear stress, tau R) on RBC hemolysis is investigated utilizing a submerged axisymmetric jet flow field. A detailed survey of the flow field is made with a laser Doppler anemometer system to obtain contour maps of the mean velocity distributions, relative turbulence intensities, and tau R distributions in the field prior to conducting the experiment of sampling and analyzing the cells free-hemoglobin in the field. A new two-point sampling technique, developed in this laboratory, allows collections of RBC samples from selected locations in the flow field so that a relationship between the local shear stress level and the cell damage may be established. The threshold level of tau R responsible for incipient hemolysis is found to be approximately 400 Newtons per square meter (N/m2), below which a sublethal region of zero hemolysis is observed.