Compensation for Electrode Detachment in Electrical Impedance Tomography with Wearable Textile Electrodes.

Electrical impedance tomography (EIT) is a radiation-free and noninvasive medical image reconstruction technique in which a current is injected and the reflected voltage is received through electrodes. EIT electrodes require good connection with the skin for data acquisition and image reconstruction. However, detached electrodes are a common occurrence and cause measurement errors in EIT clinical applications. To address these issues, in this study, we proposed a method for detecting faulty electrodes using the differential voltage value of the detached electrode in an EIT system. Additionally, we proposed the voltage-replace and voltage-shift methods to compensate for invalid data from the faulty electrodes. In this study, we present the simulation, experimental, and in vivo chest results of our proposed methods to verify and evaluate the feasibility of this approach.

Dry Wearable Textile Electrodes for Portable Electrical Impedance Tomography.

Electrical impedance tomography (EIT), a noninvasive and radiation-free medical imaging technique, has been used for continuous real-time regional lung aeration. However, adhesive electrodes could cause discomfort and increase the risk of skin injury during prolonged measurement. Additionally, the conductive gel between the electrodes and skin could evaporate in long-term usage and deteriorate the signal quality. To address these issues, in this work, textile electrodes integrated with a clothing belt are proposed to achieve EIT lung imaging along with a custom portable EIT system. The simulation and experimental results have verified the validity of the proposed portable EIT system. Furthermore, the imaging results of using the proposed textile electrodes were compared with commercial electrocardiogram electrodes to evaluate their performance.

Acoustic-Field Beamforming for Low-Power Portable Ultrasound.

Portable ultrasound has been extensively used for diagnostic applications in health monitoring, emergency rooms, and ambulances. However, these handheld ultrasound systems may suffer from heat and battery issues attributed to the large power consumption of the transmitter. Additionally, the largest portion of the direct current (DC) power consumption can be attributed to the amplifier in the digital-to-analog converter (DAC) of the transmitter and to the analog-to-digital converter (ADC) of the receiver. Therefore, the number of transmit/receive channels in a portable ultrasound instrument is one of the crucial design factors regarding heat and battery related issues. To address these problems, we propose an acoustic-field beamforming (AFB) technique for low-power portable ultrasound systems with a single receive and five transmit channels. Finally, the simulation, experimental, and in vivo results verified the feasibility of this approach.

Effects of recombinant adenovirus-mediated hypoxia-inducible factor-1alpha gene on proliferation and differentiation of endogenous neural stem cells in rats following intracerebral hemorrhage.

OBJECTIVE: To investigate the effects of adenovirus (Ad)-mediated hypoxia-inducible factor-1alpha (HIF-1α) gene on proliferation and differentiation of endogenous neural stem cells (NSCs) in rats following intracerebral hemorrhage (ICH) and the underlying mechanisms. METHODS: A total of 120 specific pathogen-free, adult, male Sprague-Dawley rats were included in this study. After establishment of ICH models in rats, PBS, Ad, or Ad-HIF-1α was administered via the ischemic ventricle. On the 1st, 7th, 14th, 21st and 28th d after ICH, rat neurological deficits were scored, doublecortin (DCX) expression in the subventricular zone cells was detected by immunohistochemical staining, and 5-bromo-2'-deoxyuridine (BrdU)-, BrdU/DCX-, and BrdU/glial fibrillary acidic protein-positive cells in the subventricular zone were counted using immumofluorescence method among PBS, Ad, and Ad-HIF-1α groups. RESULTS: On the 7th, 14th, 21st and 28th d after ICH, neurological deficit scores in the Ad-HIF-1α group were significantly lower than in the PBS and Ad groups (P<0.05). In the Ad-HIF-1α group, DCX expression was significantly increased on the 7th d, peaked on the 14th d, and then gradually decreased. In the Ad-HIF-1α group, BrdU-positive cells were significantly increased over time course, and significant difference in BrdU-positive cell counts was observed when compared with the PBS and Ad groups at each time point (P<0.01 or 0.05). On the 7th, 14th, 21st and 28th d after ICH, the number of DCX-, BrdU-, BrdU/DCX-, and BrdU/DCX-positive cells in the Ad-HIF-1α group was significantly greater than in the PBS and Ad groups (P<0.05). CONCLUSIONS: HIF-1α gene can promote the proliferation, migration and differentiation of endogenous neural stem cells after ICH, thereby contributing to neurofunctional recovery after ICH.

An interactive method for achieving ergonomically optimum conditions during laparoscopic surgery.

Laparoscopy is widely used during living kidney donation, nephrectomy, bariatric surgery, and surgery for gastrointestinal tumors and colorectal cancer. However, laparoscopic surgery requires prolonged use of instruments and has low mechanical efficiency. In addition, to meet specific surgical demands while visualizing the surgical area on the screen, surgical personnel frequently violate the postures proposed by human factor engineering; this naturally results in a physical burden on the personnel. In this study, using laparoscopic nephrectomy as an example, an auxiliary hoisting device for surgery was designed, and pedals from a variety of equipment were integrated into the auxiliary plant. Both entity testing conducted in the hospital and 3D surgical simulation of the auxiliary plant showed that this device could improve compliance with human factor engineering recommendations during laparoscopic surgery and could also promote interaction and tacit understanding between surgical personnel, thereby providing ergonomically optimum conditions during laparoscopy.

Application of the laser Doppler flowmeter for measurement of blood pressure and functional parameters of microcirculation.

The laser Doppler flowmeter has become an effective tool for the clinical study of microcirculation with non-invasive measurements and excellent velocity resolution. Microcirculation flow measurements cannot be used as reference criteria for circulation function. Thus, the relative change in fingertip microcirculation was measured through inflation and deflation of an automatic sphygmomanometer wrapped around the arm, and the blood pressure and functional parameters of circulation, such as biological zero (BZ), peak flow (PF) and time to peak flow (tp), were determined. For 50 healthy participants, the correlation coefficients for the laser Doppler flowmeter and oscillometric results were 0.950 and 0.838 for systolic and diastolic pressure, respectively. The mean and standard errors for both methods fell within the range specified in the Association for the Advancement of Medical Instrumentation standards. The BZ of an edema patient was about 5 times higher than normal. For patients with peripheral arterial occlusive disease (PAOD), the PF could not be determined, and the tp was about twice the normal value. The accuracy of blood pressure measurements using the laser Doppler flowmeter was comparable to that of the commonly used oscillometric sphygmomanometer, and the physiological circulation functional parameters were useful in identifying signs of edema and PAOD.

A novel dynamic sensing of wearable digital textile sensor with body motion analysis.

This work proposes an innovative textile sensor system to monitor dynamic body movement and human posture by attaching wearable digital sensors to analyze body motion. The proposed system can display and analyze signals when individuals are walking, running, veering around, walking up and down stairs, as well as falling down with a wearable monitoring system, which reacts to the coordination between the body and feet. Several digital sensor designs are embedded in clothing and wear apparel. Any pressure point can determine which activity is underway. Importantly, wearable digital sensors and a wearable monitoring system allow adaptive, real-time postures, real time velocity, acceleration, non-invasive, transmission healthcare, and point of care (POC) for home and non-clinical environments.

[Prevalence and correlation factors of carotid atherosclerosis among the middle and old aged workers in an iron and steel corporation, Chongqing].

OBJECTIVE: To investigate the prevalence and correlation factors of carotid atherosclerosis (CAS) among workers of Chongqing Iron and Steel Corporation, and to offer information for the development of prevention program for cerebro-vascular disease. METHODS: 512 asymptomatic individuals (mean age 56.8 years, ranged from 45 to 80) from the subsidiary workshop of Chongqing Iron and Steel Corporation were recruited. Demographic data and serum were collected and the internal-media thickness (IMT) of the CAS and the extent of plaque formation were evaluated by B-mode ultrasound. Logistic regression analysis was used to estimate the correlation factors of CAS. Results (1) The overall prevalence of carotid atherosclerosis among the iron and steel workers was 37.6%. IMT was found as 10.2% , with the prevalence rates of nonstenotic plaque and stenotic plaque were 25.0% and 2.4% respectively. (2) It was shown by logistic regression analysis that age (OR = 1.289, 95% CI: 1.014-1.568, P < 0.001), smoking (OR = 1.420, 95% CI: 0.802-3.872, P < 0.001), hypertension (OR= 4.530, 95% CI: 3.952-6.753, P < 0.001) , diabetes mellitus (OR = 2.285, 95% CI: 1.008-5.057, P < 0.001), HsCRP (OR = 1.273, 95% CI: 0.479-2.889, P = 0.037), TC (OR = 1.032, 95% CI: 0.320-1.882, P = 0.047) and LDL-C (OR = 2.313, 95% CI: 1.237-4.331, P = 0.008) were significantly associated with the severity of CAS. (3) Prevalence of the CAS increased with the increasing number of correlation factors. CONCLUSION: The prevalence of CAS among the iron and steel workers was higher than those in ordinary people of the same age. Age, smoking, hypertension, diabetes mellitus, HsCRP, TC and LDL-C were independent risk factors related to CAS. The prevalence of CAS was increasing parallel to the number of correlation factors.

A double-injection model of intracerebral hemorrhage in rabbits.

We aimed to develop a double-injection model of intracerebral hemorrhage (ICH) in rabbits and to evaluate it as a tool for investigating post-ICH brain injury. Rabbits were injected with 300microL fresh autologous whole blood into the right basal ganglia. Behavioral changes were rated, brain water content (BWC) was measured and brain tissue morphology was also examined. ICH was established in 93.5% of the blood injection group. At 1, 3 and 7 days after ICH, there were significant differences in the total neurological scores (p<0.01) and BWC (p<0.01) between a sham-operated group and the ICH group. These findings suggest that the model produces a persistent neurological deficit, hematoma volume and perihematomal edema and closely mimics human hypertensive basal ganglia ICH; it is a controllable and reproducible hematoma that lends itself to quantitative investigation.

[Therapeutic effect of hypoxia-inducible factor-1alpha on focal cerebral ischemia: experiment with rats].

OBJECTIVE: To construct a recombinant adenoviral vector carrying HIF-1alpha gene and explore the therapeutic effect of HIF-1alpha on focal cerebral ischemia in adult rats. METHODS: The AdEasy System was used to construct the recombinant adenoviral vector carrying HIF-1alpha gene and green fluorescent protein and PCR was used to identify the HIF-1alpha gene. Middle cerebral artery occlusion (MCAo) and reperfusion models were established and divided into Ad-HIF-1alpha group, Ad group and NS group. After Ad-HIF-1alpha, Ad and NS were injected into the ischemic ventricle, expression of Ad-HIF-1alpha was observed and its therapeutic effect was evaluated by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining and neurological severity scores. RESULTS: GFP expression distributed apart from the ventricle and reached a peak at 14 days and persisted for about 4 weeks under fluorescent microscope. The neurological severity scores was 2.4 +/- 0.5 at 24 h in Ad-HIF-1alpha group and there was no statistical significance compared with Ad group (2.6 +/- 0.5) and NS group (2.7 +/- 0.7) (P > 0.05). The scores were 1.6 +/- 0.7 at 48 h and 0.9 +/- 0.6 at 72 h in Ad-HIF-1alpha group, and there were statistical significance compared with Ad group (2.9 +/- 0.6 and 3.2 +/- 0.6 respectively) and NS group (3.0 +/- 0.7 and 3.2 +/- 0.8) (P < 0.05). The infarct volume was 81.2 mm(3) +/- 1.4 mm(3) at 72 h in Ad-HIF-1alpha group and there was statistical significance compared with Ad group (173.9 mm(3) +/- 1.3 mm(3)) and NS group (171.7 mm(3) +/- 6.2 mm(3)) (P < 0.05). CONCLUSION: HIF-1alpha gene had definite therapeutic effect on focal cerebral ischemia in adult rats, which settles a foundation for next HIF-1alpha gene study and clinic application.

[Study in the mechanism of Shuxuetong injection on antithrombosis and thrombolysis].

OBJECTIVE: To study the effect of Shuxuetong injection on cerebral tissue and brain microvascular endothelial cell(BMEC) in secreting tissue-type plasminogen activator (tPA). METHOD: The experiment in vivo was designed for three groups: sham-operation group, focal cerebral ischemia model group, Shuxuetong injection-treated group. The gene expression and the activity of tPA on brains were detected by RT-PCR and chromogenic substrate analysis respectively after treatment for five days; The experiment in vitro: The cultured BMEC were divided into experimental group and control group. The Shuxuetong injection were added into experimental group and the BMECs in the experimatal groups were treated for 24 h. The gene expression and the activity of tPA on cultured BMEC were detected by RT-PCR and chromogenic substrate analysis respectively. RESULT: The gene expression and the content of tPA on both cerebral tissue and BMEC in the experimatal groups were significantly higher than that in the control groups. CONCLUSION: Shuxuetong injection could accelerate secretion of tPA, and therefore enhance fibrinolysis.