Extracting physiological information in experimental biology via Eulerian video magnification.

BACKGROUND: Videographic material of animals can contain inapparent signals, such as color changes or motion that hold information about physiological functions, such as heart and respiration rate, pulse wave velocity, and vocalization. Eulerian video magnification allows the enhancement of such signals to enable their detection. The purpose of this study is to demonstrate how signals relevant to experimental physiology can be extracted from non-contact videographic material of animals. RESULTS: We applied Eulerian video magnification to detect physiological signals in a range of experimental models and in captive and free ranging wildlife. Neotenic Mexican axolotls were studied to demonstrate the extraction of heart rate signal of non-embryonic animals from dedicated videographic material. Heart rate could be acquired both in single and multiple animal setups of leucistic and normally colored animals under different physiological conditions (resting, exercised, or anesthetized) using a wide range of video qualities. Pulse wave velocity could also be measured in the low blood pressure system of the axolotl as well as in the high-pressure system of the human being. Heart rate extraction was also possible from videos of conscious, unconstrained zebrafish and from non-dedicated videographic material of sand lizard and giraffe. This technique also allowed for heart rate detection in embryonic chickens in ovo through the eggshell and in embryonic mice in utero and could be used as a gating signal to acquire two-phase volumetric micro-CT data of the beating embryonic chicken heart. Additionally, Eulerian video magnification was used to demonstrate how vocalization-induced vibrations can be detected in infrasound-producing Asian elephants. CONCLUSIONS: Eulerian video magnification provides a technique to extract inapparent temporal signals from videographic material of animals. This can be applied in experimental and comparative physiology where contact-based recordings (e.g., heart rate) cannot be acquired.

Pulseless electrical activity following traumatic cardiac arrest: Sign of life or death?

BACKGROUND: Generally considered a sign of life, PEA is the most common arrhythmia encountered following pre-hospital traumatic cardiac arrest. Some recommend cardiac ultrasound (CUS) to determine cardiac wall motion (CWM) prior to terminating resuscitation efforts. This purpose of this study was to evaluate the outcomes of patients with traumatic cardiac arrest presenting with PEA, with and without CWM. METHODS: Trauma patients who underwent pre-hospital CPR were identified from the registries of two level-1 trauma centers. Pre-hospital management by emergency medical transport services was guided by advanced life support protocols. The on-duty trauma surgeon directed the resuscitations and performed or supervised CUS and determined CWM. RESULTS: Among 277 patients who underwent pre-hospital CPR, 110 patients had PEA on arrival to ED. 69 (62.7%) were injured by blunt mechanisms. Median CPR duration was 20.0 and 8.0 min for pre-hospital and ED, respectively. Sixty-three patients (22.7%) underwent resuscitative thoracotomy. One hundred seventy-two patients (62.1%) received CUS and of these 32 (18.6%) had CWM. CWM was significantly associated with survival to hospital admission (21.9% vs. 1.4%; P < 0.001); however, no patient with CUS survived to hospital discharge. Overall, only one patient with PEA on arrival survived to discharge. CONCLUSION: Following pre-hospital traumatic cardiac arrest, PEA on arrival portends death. Although CWM is associated with survival to admission, it is not associated with meaningful survival. Heroic resuscitative measures may be unwarranted for PEA following pre-hospital traumatic arrest, regardless of CWM.

Biodegradable and flexible arterial-pulse sensor for the wireless monitoring of blood flow.

The ability to monitor blood flow is critical to patient recovery and patient outcomes after complex reconstructive surgeries. Clinically available wired implantable monitoring technology requires careful fixation for accurate detection and needs to be removed after use. Here, we report the design of a pressure sensor, made entirely of biodegradable materials and based on fringe-field capacitor technology, for measuring arterial blood flow in both contact and non-contact modes. The sensor is operated wirelessly through inductive coupling, has minimal hysteresis, fast response times, excellent cycling stability, is highly robust, allows for easy mounting and eliminates the need for removal, thus reducing the risk of vessel trauma. We demonstrate the operation of the sensor with a custom-made artificial artery model and in vivo in rats. This technology may be advantageous in real-time post-operative monitoring of blood flow after reconstructive surgery.

Highly Sensitive and Durable Structured Fibre Sensors for Low-Pressure Measurement in Smart Skin.

Precise measurements of low pressure are highly necessary for many applications. This study developed novel structured fibre sensors embedded in silicone, forming smart skin with high sensitivity, high durability, and good immunity to crosstalk for precise measurement of pressure below 10 kPa. The transduction principle is that an applied pressure leads to bending and stretching of silicone and optical fibre over a purposely made groove and induces the axial strain in the gratings. The fabricated sensor showed high pressure sensitivity up to 26.8 pm/kPa and experienced over 1,000,000 cycles compression without obvious variation. A theoretical model of the sensor was presented and verified to have excellent agreement with experimental results. The prototype of smart leg mannequin and wrist pulse measurements indicated that such optical sensors can precisely measure low-pressure and can easily be integrated for smart skins for mapping low pressure on three-dimensional surfaces.

The POCUS Pulse Check: A Case Series on a Novel Method for Determining the Presence of a Pulse Using Point-of-Care Ultrasound.

BACKGROUND: During cardiopulmonary resuscitation, pulse checks must be rapid and accurate. Despite the importance placed on the detection of a pulse, several studies have shown that health care providers have poor accuracy for detection of central pulses by palpation. To date, the use of point-of-care ultrasound (POCUS) in cardiac arrest has focused on the presence of cardiac standstill and diagnosing reversible causes of the arrest. OBJECTIVE: This case series highlights a simple, novel approach to determine whether pulses are present or absent by using POCUS compression of the central arteries. DISCUSSION: Using this technique, we found that a POCUS pulse check can be consistently performed in < 5 s and is clearly determinate, even when palpation yields indeterminate results. CONCLUSIONS: In this case series, the POCUS pulse check was a valuable adjunct that helped to change management for critically ill patients. Future prospective studies are required to determine the accuracy of this technique and the impact on patient outcomes in a larger cohort.

A New Blood Pulsation Simulator Platform Incorporating Cardiovascular Physiology for Evaluating Radial Pulse Waveform.

To meet the need for "standard" testing system for wearable blood pressure sensors, this study intends to develop a new radial pulsation simulator that can generate age-dependent reference radial artery pressure waveforms reflecting the physiological characteristics of human cardiovascular system. To closely duplicate a human cardiovascular system, the proposed simulator consists of a left ventricle simulation module, an aorta simulation module, a peripheral resistance simulation module, and a positive/negative pressure control reservoir module. Simulating physiologies of blood pressure, the compliance chamber in the simulator can control arterial stiffness to produce age-dependent pressure waveforms. The augmentation index was used to assess the pressure waveforms generated by the simulator. The test results show that the simulator can generate and control radial pressure waveforms similar to human pulse signals consisting of early systolic pressure, late systolic pressure, and dicrotic notch. Furthermore, the simulator's left ventricular pressure-volume loop results demonstrate that the simulator exhibits mechanical characteristics of the human cardiovascular system. The proposed device can be effectively used as a "standard" radial artery pressure simulator to calibrate the wearable sensor's measurement characteristics and to develop more advanced sensors. The simulator is intended to serve as a platform for the development, performance verification, and calibration of wearable blood pressure sensors. It will contribute to the advancement of the wearable blood pressure sensor technology, which enables real-time monitoring of users' radial artery pressure waveforms and eventually predicting cardiovascular diseases.

A Wearable Multifunctional Pulse Monitor Using Thermosensation-Based Flexible Sensors.

OBJECTIVE: This study proposes a novel wearable pulse monitoring system, which can realize the synchronous measurements of pulse wave, skin, temperature, and pulse wave velocity (PWV). METHODS: A flexible sensor based on thermosensation is used to detect pressure and temperature stimuli simultaneously. A total of two sensors are integrated to detect pulse transit along two specific points of the artery, e.g., Cun and Chi at a wrist, the data of which are subsequently used to figure out the PWV by using a tailor-designed algorithm conducted in a microprocessor. Calibration experiments and application cases are conducted to validate the effectiveness of the monitor. RESULTS: The developed monitor detects the physiological signals of pulse wave, PWV, and skin temperature simultaneously. In addition, the monitor can measure the pulse changes before and after exercises and track skin temperature variations when warming and cooling. Moreover, the monitor can be also used to detect the local PWV at the wrist. CONCLUSION: The synchronous measurements of pulse wave, skin temperature, and PWV using a wearable monitor are feasible. SIGNIFICANCE: The monitor is small, simple-structured, with multifunction, and thus provides a promising auxiliary approach for traditional Chinese medicine pulse diagnosis.

Using the Pulse Contour Method to Measure the Changes in Stroke Volume during a Passive Leg Raising Test.

The pulse contour method is often used with the Windkessel model to measure stroke volume. We used a digital pressure and flow sensors to detect the parameters of the Windkessel model from the pulse waveform. The objective of this study was to assess the stability and accuracy of this method by making use of the passive leg raising test. We studied 24 healthy subjects (40 ± 9.3 years), and used the Medis® CS 1000, an impedance cardiography, as the comparing reference. The pulse contour method measured the waveform of the brachial artery by using a cuff. The compliance and resistance of the peripheral artery was detected from the cuff characteristics and the blood pressure waveform. Then, according to the method proposed by Romano et al., the stroke volume could be measured. This method was implemented in our designed blood pressure monitor. A passive leg raising test, which could immediately change the preloading of the heart, was done to certify the performance of our method. The pulse contour method and impedance cardiography simultaneously measured the stroke volume. The measurement of the changes in stroke volume using the pulse contour method had a very high correlation with the Medis® CS 1000 measurement, the correlation coefficient of the changed ratio and changed differences in stroke volume were r² = 0.712 and r² = 0.709, respectively. It was shown that the stroke volume measured by using the pulse contour method was not accurate enough. But, the changes in the stroke volume could be accurately measured with this pulse contour method. Changes in stroke volume are often used to understand the conditions of cardiac preloading in the clinical field. Moreover, the operation of the pulse contour method is easier than using impedance cardiography and echocardiography. Thus, this method is suitable to use in different healthcare fields.

Analysis of a Pulse Rate Variability Measurement Using a Smartphone Camera.

Background: Heart rate variability (HRV) provides information about the activity of the autonomic nervous system. Because of the small amount of data collected, the importance of HRV has not yet been proven in clinical practice. To collect population-level data, smartphone applications leveraging photoplethysmography (PPG) and some medical knowledge could provide the means for it. Objective: To assess the capabilities of our smartphone application, we compared PPG (pulse rate variability (PRV)) with ECG (HRV). To have a baseline, we also compared the differences among ECG channels. Method: We took fifty parallel measurements using iPhone 6 at a 240 Hz sampling frequency and Cardiax PC-ECG devices. The correspondence between the PRV and HRV indices was investigated using correlation, linear regression, and Bland-Altman analysis. Results: High PPG accuracy: the deviation of PPG-ECG is comparable to that of ECG channels. Mean deviation between PPG-ECG and two ECG channels: RR: 0.01 ms-0.06 ms, SDNN: 0.78 ms-0.46 ms, RMSSD: 1.79 ms-1.21 ms, and pNN50: 2.43%-1.63%. Conclusions: Our iPhone application yielded good results on PPG-based PRV indices compared to ECG-based HRV indices and to differences among ECG channels. We plan to extend our results on the PPG-ECG correspondence with a deeper analysis of the different ECG channels.

Validación de la toma del pulso arterial en atención primaria para la detección de fibrilación auricular y otros trastornos del ritmo cardiaco en mayores de 65 años / Validation of taking arterial pulse in Primary Care for the detection of atrial fibrillation and other cardiac rhythm disorders in patients over 65 years old

Introducción. La fibrilación auricular es la arritmia más frecuente en la práctica clínica y conlleva importantes implicaciones pronósticas. Comprobar la validez y la fiabilidad de la toma del pulso arterial (TPA) de los profesionales de atención primaria en la detección de fibrilación auricular y otros trastornos del ritmo en pacientes mayores de 65 años ha sido el objeto de este estudio. Material y métodos. Estudio observacional descriptivo, multicéntrico, de validación de una prueba diagnóstica, anidado en un ensayo clínico controlado. Emplazamiento: 39 centros de salud del Sistema Nacional de Salud. Participaron 318 médicos y enfermeros en el análisis de la validez y 166 en el de la fiabilidad. Se convocó a los profesionales a una reunión donde se tomaron el pulso arterial y se les entregó 4 ECG para que los interpretaran. Los participantes realizaron la TPA, seguido de un ECG en 864 pacientes para confirmar el ritmo cardiaco. Para valorar la validez criterial se estimaron la sensibilidad, especificidad y valores predictivos, y para comprobar la reproducibilidad, el índice de concordancia simple. Resultados. La sensibilidad de la TPA para la detección de fibrilación auricular fue del 99,4% (IC 95%: 97,9-100,0), y la especificidad del 30,7% (IC 95%: 26,1-35,3), el valor predictivo positivo fue 36,6% (IC 95%: 32,0-41,2) y el valor predictivo negativo 99,2% (IC 95%: 97,3-100,0). La concordancia simple entre los investigadores y el cardiólogo para el diagnóstico electrocardiográfico de fibrilación auricular osciló entre el 84,9 y el 91,6%. Conclusiones. La TPA tiene una alta sensibilidad pero una baja especificidad para detectar una fibrilación auricular. Es una prueba fiable, por lo que resulta de utilidad para el cribado oportunista de arritmias en pacientes mayores de 65 años que acuden a atención primaria (AU)

Introduction. Atrial fibrillation (AF) is the most frequent arrhythmia in clinical practice and has important prognostic implications. The objective of this study was to demonstrate the validity and the reliability of taking the arterial pulse (TAP) in patients over 65 years for detecting in AF and other rhythm disorders. Materials and methods. A descriptive, observational, multicentre study to validate a diagnostic test within in a controlled clinical trial. Setting: 39 Primary Care Centres in the Spanish National Health Service. A total of 318 physicians and nurses took part in the analysis of validity, and 166 of them took part in the analysis of reliability. The professionals were previously called to a meeting in which they took the arterial pulses, and were given 4 ECGs to interpret. The participants TAP of 864 patients followed by an ECG to confirm the cardiac rhythm. Sensitivity, specificity and predictive values were estimated to assess the criterial validity and the simple concordance index to check reproducibility. Results. The sensitivity of pulse measurement for detecting AF detection was 99.4% (95% CI: 97.9-100.0), with a specificity of 30.7% (95% CI: 26.1-35.3), a positive predictive value of 36.6% (95% CI 32.0-41.2), and negative predictive value of 99.2% (97.3-100.0). The simple concordance between the researchers and the cardiologist for the ECG diagnosis of AF ranged between 84.9% and 91.6%. Conclusions. The TAP has a high sensitivity but a low specificity to detect AF. It is a reliable test for the opportunistic screening of arrhythmias in patients aged over 65 years (AU)

An advanced selective liquid-metal plating technique for stretchable biosensor applications.

This paper presents a novel stretchable pulse sensor fabricated by a selective liquid-metal plating process (SLMP), which can conveniently attach to the human skin and monitor the patient's heartbeat. The liquid metal-based stretchable pulse sensor consists of polydimethylsiloxane (PDMS) thin films and liquid metal functional circuits with electronic elements that are embedded into the PDMS substrate. In order to verify the utility of the fabrication process, various complex liquid-metal patterns are achieved by using the selective wetting behavior of the reduced liquid metal on the Cu patterns of the PDMS substrate. The smallest liquid-metal pattern is approximately 2 µm in width with a uniform surface. After verification, a transparent flowing LED light with programmed circuits is realized and exhibits stable mechanical and electrical properties under various deformations (bending, twisting and stretching). Finally, based on SLMP, a wireless pulse measurement system is developed which is composed of the liquid metal-based stretchable pulse sensor, a Bluetooth module, an Arduino development board, a laptop computer and a self-programmed visualized software program. The experimental results reveal that the portable non-invasive pulse sensor has the potential to reduce costs, simplify biomedical diagnostic procedures and help patients to improve their life in the future.

Digital auscultation of the uterine artery: a measure of uteroplacental perfusion.

This observational study investigated digital auscultation for the purpose of assessing the clinical feasibility of monitoring vascular sounds in pregnancy. The study was performed at the Regional Hospital Viborg, Denmark, and included 29 pregnant women, 10 non-pregnant women and 10 male participants. Digital auscultation was performed with an electronic stethoscope bilaterally near the uterine arteries and correlated to the clinical diagnosis of preeclampsia (PE), intrauterine growth restriction (IUGR) or normal pregnancy in the group of pregnant participants. In the group of non-pregnant participants, digital auscultation was performed as control measurements in the same anatomical positions. The auscultations displayed pulse waveforms comprising systolic and diastolic periods in 20 of the 29 pregnant participants. However, in the non-pregnant and male participants, the pulse waveforms were absent. The pulsatile patterns are thus likely to originate from the arteries in relation to the pregnant uterus. In the participants displaying pulse waveforms, the presence of a dicrotic notch appeared with a sensitivity of 89% and a specificity of 100% in the discrimination of normal pregnancies (n = 11) from pregnancies with PE or IUGR (n = 9), (p < 0.001). This preliminary study shows the potential of identifying vascular complications during pregnancy such as preeclampsia and intrauterine growth restriction. The morphology of the derived pulse contour should be investigated and could be further developed to identify pathophysiology.

Encuesta española de reanimación neonatal 5 años después. ¿Vamos mejorando? / Five years after the Spanish neonatal resuscitation survey. Are we improving?

INTRODUCCIÓN: Se analizan prácticas de reanimación neonatal en salas de partos (SP) de centros hospitalarios españoles. MÉTODOS: Se envió un cuestionario por centro a neonatólogos responsables de la atención del RN en SP de hospitales españoles. RESULTADOS: De 180 cuestionarios enviados, se cumplimentaron 155 (86%); 71 centros fueron de nivel I-II(46%) y 84 de nivel III (54%). La familia y el equipo médico participaron en decisiones de no reanimar o interrumpir la reanimación en el 74,2% de los centros. La disponibilidad de 2 o más reanimadores fue del 80% (94,0% en nivel II I y 63,9% en nivel I-II, p < 0,001). En un 90,3% de centros se realizan cursos de Reanimación. En centros de nivel III fueron más frecuentes los mezcladores de gases, pulsioxímetros, ventiladores manuales y envoltorios de plástico. El uso de envoltorios de polietileno fue del 63,9%. En RN a término se inició la reanimación con aire en el 89,7% de los centros. El dispositivo más usado para aplicar VPP fue el «ventilador manual» (78,6% en nivel III y 42,3% en nivel I-II, p < 0,001). En el 91,7% de los centros de nivel III se utilizó CPAP precoz en prematuros. En los últimos 5 años han mejorado prácticas como son la formación de profesionales, el uso de pulsioxímetros y de CPAP precoz. CONCLUSIONES: Existe una mejora progresiva en algunas prácticas de reanimación neonatal. Se encuentran diferencias en aspectos generales, equipamientos y protocolos de actuación durante la reanimación y transporte entre unidades de diferentes niveles

INTRODUCTION: An analysis is presented of delivery room (DR) neonatal resuscitation practices in Spanish hospitals. METHODS: A questionnaire was sent by e-mail to all hospitals attending deliveries in Spain. RESULTS: A total of 180 questionnaires were sent, of which 155 were fully completed (86%). Less than half (71, 46%) were level I or II hospitals, while 84 were level III hospital (54%). In almost three-quarters (74.2%) of the centres, parents and medical staff were involved in the decision on whether to start resuscitation or withdraw it. A qualified resuscitation team (at least two members) was available in 80% of the participant centres (63.9% level I-II, and 94.0% level III,P<.001). Neonatal resuscitation courses were held in 90.3% of the centres. The availability of gas blenders, pulse oximeters, manual ventilators, and plastic wraps was higher in level IIIhospitals. Plastic wraps for pre-term hypothermia prevention were used in 63.9% of the centres (40.8% level I-IIand 83.3% level III, P<.001). Term newborn resuscitation was started on room air in 89.7% of the centres. A manual ventilator (T-piece) was the device used in most cases when ventilation was required (42.3% level I-IIand 78.6% level III, P<.001). Early CPAP in preterm infants was applied in 91.7% of the tertiary hospitals. In last 5 years some practices have improved, such neonatal resuscitation training, pulse oximeter use, or early CPAP support. CONCLUSIONS: There is an improvement in some practices of neonatal resuscitation. Significant differences have been found as regards the equipment or practices in the DR, when comparing hospitals of different levels of care

Pulsioximetría frente al monitor de electrocardiograma para la determinación de la frecuencia cardíaca durante la reanimación del recién nacido pretérmino / Pulse oximetry versus electrocardiogram for heart rate assessment during resuscitation of the preterm infant

INTRODUCCIÓN: La medición de frecuencia cardíaca (FC) es esencial durante la reanimación neonatal y se realiza habitualmente mediante auscultación o pulsioximetría (PO). El objetivo de este estudio es analizar si durante la reanimación del recién nacido prematuro la medición de la FC mediante ECG es tan precoz y fiable como la PO. MATERIAL Y MÉTODOS: Se realizó video-grabación de la reanimación de 39 recién nacidos prematuros (<32 semanas o <1.500g), registrando medidas de FC simultáneamente mediante ECG y PO cada 5 s desde el nacimiento hasta los 10 min de vida. Se determinó el tiempo necesario para colocación, obtención de lectura fiable y pérdida de señal de ambos dispositivos, así como la proporción de medida fiable de FC al inicio de cada maniobra de reanimación. RESULTADOS: El tiempo de colocación fue menor en ECG que en PO (17,10±1,28 s vs. 26,64±3,01 s; p < 0,05). Igualmente, el tiempo desde el fin de la colocación hasta la obtención de una lectura fiable fue menor para ECG que para PO (26,38±3,41 s vs. 87,28±12,11 s; p < 0,05). La proporción de medidas fiables de la FC al inicio de la reanimación fue menor en PO (PO vs. ECG para ventilación con presión positiva: 10,52 vs. 57,89%; p < 0,05; intubación: 33,33 vs. 91,66%; p < 0,05). La PO subestimó la FC con medidas inferiores a las del ECG durante los primeros 6 min de vida (p < 0,05 entre los 150 y 300 s). CONCLUSIONES: En la reanimación del prematuro la obtención de la FC fiable es más tardía con la PO que con ECG; además, la PO subestima la FC en los primeros momentos de la reanimación

BACKGROUND: Heart rate (HR) assessment is essential during neonatal resuscitation, and it is usually done by auscultation or pulse oximetry (PO). The aim of the present study was to determine whether HR assessment with ECG is as fast and reliable as PO during preterm resuscitation. MATERIAL AND METHODS: Thirty-nine preterm (<32 weeks of gestational age and/or<1.500g of birth weight) newborn resuscitations were video-recorded. Simultaneous determinations of HR using ECG and PO were registered every 5s for the first 10min after birth. Time needed to place both devices and to obtain reliable readings, as well as total time of signal loss was registered. The proportion of reliable HR readings available at the beginning of different resuscitation manoeuvres was also determined. RESULTS: Time needed to connect the ECG was shorter compared with the PO (26.64±3.01 vs. 17.10±1.28 s, for PO and ECG, respectively, P<.05). Similarly, time to obtain reliable readings was shorter for the ECG (87.28±12.11 vs. 26.38±3.41 s, for PO and ECG, respectively,P<.05). Availability of reliable HR readings at initiation of different resuscitation manoeuvres was lower with the PO (PO vs. ECG for positive pressure ventilation: 10.52 vs. 57.89% P<.05; intubation: 33.33 vs. 91.66%, P<.05). PO displayed lower HR values during the first 6min after birth (P<.05, between 150 and 300s). CONCLUSIONS: Reliable HR is obtained later with the PO than with the ECG during preterm resuscitation. PO underestimates HR in the first minutes of resuscitation

An Optimal Pulse System Design by Multichannel Sensors Fusion.

Pulse diagnosis, recognized as an important branch of traditional Chinese medicine (TCM), has a long history for health diagnosis. Certain features in the pulse are known to be related with the physiological status, which have been identified as biomarkers. In recent years, an electronic equipment is designed to obtain the valuable information inside pulse. Single-point pulse acquisition platform has the benefit of low cost and flexibility, but is time consuming in operation and not standardized in pulse location. The pulse system with a single-type sensor is easy to implement, but is limited in extracting sufficient pulse information. This paper proposes a novel system with optimal design that is special for pulse diagnosis. We combine a pressure sensor with a photoelectric sensor array to make a multichannel sensor fusion structure. Then, the optimal pulse signal processing methods and sensor fusion strategy are introduced for the feature extraction. Finally, the developed optimal pulse system and methods are tested on pulse database acquired from the healthy subjects and the patients known to be afflicted with diabetes. The experimental results indicate that the classification accuracy is increased significantly under the optimal design and also demonstrate that the developed pulse system with multichannel sensors fusion is more effective than the previous pulse acquisition platforms.

[The campaign of returning to the ancient in sphygmology in the Republican Period as viewed from Mai xue cong shu (Series of Pulse Taking)].

From the Southern and Northern Dynasties to the beginning of the Northern Song Dynasty, the models of "master and apprentice" and "physician of long family tradition for generations" were the main ways for teaching medical knowledge. With the rapid amassment of medical books in the Due to the rapid transmission of western science and technology into China in the Republican period, the art of pulse taking had been treated as unscientific. Yao Xinyuan advocated the recovery of ancient pulse taking of the three-portion approach, i.e., taking the pulses at the neck, hands, and feet for comparison. To spread this idea, Yao and Zhang Ziying compiled the Mai xue cong shu (Series of Pulse Taking) in 1937-1947. Altogether 4 issues were published carrying 29 articles concerning the theoretical exploration, experimental research, and clinical practice. Their thinking and approaches were influential to the study and development of modern sphygmology.

Analysis of Vacuous Pulse and Replete Pulse Using a Clip-type Pulsimeter Equipped with a Hall Sensor.

A logistic regression equation for the vacuous pulse and the replete pulse was determined based on data obtained using a clip-type pulsimeter equipped with a Hall device that sensed the change in the magnetic field due to the minute movement of a radial artery. To evaluate the efficacy of the two different pulses from the deficiency and the excess syndrome groups, we performed a clinical trial, and we used a statistical regression analysis to process the clinical data from the 180 participants who were enrolled in this study. The ratio of the systolic peak's amplitude to its time in the pulse's waveform was found to be a major efficacy parameter for differentiating between the vacuous pulse and the replete pulse using an empirical equation that was deduced from the data using a statistical logistic regression method. This logistic regression equation can be applied to develop a novel algorithm for pulse measurements based on Oriental medical diagnoses.

Highly stretchable resistive pressure sensors using a conductive elastomeric composite on a micropyramid array.

A stretchable resistive pressure sensor is achieved by coating a compressible substrate with a highly stretchable electrode. The substrate contains an array of microscale pyramidal features, and the electrode comprises a polymer composite. When the pressure-induced geometrical change experienced by the electrode is maximized at 40% elongation, a sensitivity of 10.3 kPa(-1) is achieved.

Stretchable optoelectronic circuits embedded in a polymer network.

Stretchable optoelectronic circuits, incorporating chip-level LEDs and photodiodes in a silicone membrane, are demonstrated. Due to its highly miniaturized design and tissue-like mechanical properties, such an optical circuit can be conformally applied to the epidermis and be used for measurement of photoplethysmograms. This level of optical functionality in a stretchable substrate is potentially of great interest for personal health monitoring.

Acquisition technology research of EEG and related physiological signals under +Gz acceleration.

BACKGROUND: With the continuous improvement of maneuvering performance of modern high-performance aircraft, the protection problem of flight personnel under high G acceleration, the development as well as research on monitoring system and the equipment for human physiological signals processing which include electroencephalogram (EEG) have become more and more important. Due to the particularity of +Gz experimental conditions, the high-risk of human experiments and the great difficulty of dynamic measurement, there is little research on the synchronous acquisition technology of EEG and related physiological signals under +Gz acceleration environment. METHODS: We propose a framework to execute human experiments using the three-axial high-performance human centrifuge, develop reasonable operation mode and design a new experimental research method for EEG signal acquisition and variation characteristics on three-axial high-performance human centrifuge under the environment of +Gz acceleration. We also propose to build the synchronous real-time acquisition plan of EEG, electrocardiogram, brain blood pressure, ear pulse and related physiological signals under centrifuge +Gz acceleration with different equipments and methods. RESULTS: The good profiles of EEG, heart rate, brain blood pressure and ear pulse are obtained and analyzed comparatively. In addition, the FMS hop-by-hop continuous blood pressure and hemodynamic measurement system Portapres are successfully applied to the ambulatory blood pressure measure under centrifuge +Gz acceleration environment. CONCLUSIONS: The proposed methods establish the basis and have an important guiding significance for follow-up experiment development, EEG features spectral analysis and correlation research of all signals.