An optimization study of estimating blood pressure models based on pulse arrival time for continuous monitoring

Continuous blood pressure (BP) monitoring has a significant meaning for the prevention and early diagnosis of cardiovascular disease. However, under different calibration methods, it is difficult to determine which model is better for estimating BP. This study was firstly designed to reveal a better BP estimation model by evaluating and optimizing different BP models under a justified and uniform criterion, i.e., the advanced point-to-point pairing method (PTP). Here, the physical trial in this study caused the BP increase largely. In addition, the PPG and ECG signals were collected while the cuff bps were measured for each subject. The validation was conducted on four popular vascular elasticity (VE) models (MK-EE, L-MK, MK-BH, and dMK-BH) and one representative elastic tube (ET) model, i.e., M-M. The results revealed that the VE models except for L-MK outperformed the ET model. The linear L-MK as a VE model had the largest estimated error, and the nonlinear M-M model had a weaker correlation between the estimated BP and the cuff BP than MK-EE, MK-BH, and dMK-BH models. Further, in contrast to L-MK, the dMK-BH model had the strongest correlation and the smallest difference between the estimated BP and the cuff BP including systolic blood pressure (SBP) and diastolic blood pressure (DBP) than others. In this study, the simple MK-EE model showed the best similarity to the dMK-BH model. There were no significant changes between MK-EE and dMK-BH models. These findings indicated that the nonlinear MK-EE model with low estimated error and simple mathematical expression was a good choice for application in wearable sensor devices for cuff-less BP monitoring compared to others

A unified calibration paradigm for a better cuffless blood pressure estimation with modes of elastic tube and vascular elasticity

Although two modes of elastic tube (ET) and vascular elasticity (VE) have been well explored for cuffless continuous blood pressure (BP) monitoring estimation, the initial calibration with these two models could be derived from different mathematical mechanisms for BP estimation. The study is aimed at evaluating the performance of VE and ET models by means of an advanced point-to-point (aPTP) pairing calibration. The cuff BPs were only taken up while the signals of PPG and ECG were synchronously acquired from individual subjects. Two popular VE models together with one representative ET model were designated to study aPTP as a unified assessment criterion. The VE model has demonstrated the stronger correlation r of 0.89 and 0.86 of SBP and DBP, respectively, and the lower estimated BP error of -0.01±5.90 (4.55) mmHg and 0.04±4.40 (3.38) mmHg of SBP and DBP, respectively, than the ET model. With the ET model, there is a significant difference between the methods of conventional least-square (LS) calibration and aPTP calibration (p<0.05). These results showed that the VE model surpasses the ET model under the same uniform calibration. The outcome has been unveiled that the selection of initial calibration methods was vital to work out diastolic BP with the ET model. The study revealed an evident fact about initial sensitivity between the modes of different BP estimation and initial calibration

A revised point-to-point calibration approach with adaptive errors correction to weaken initial sensitivity of cuff-less blood pressure estimation

Initial calibration is a great challenge for cuff-less blood pressure (BP) measurement. The traditional one point-to-point (oPTP) calibration procedure only uses one sample/point to obtain unknown parameters of a specific model in a calm state. In fact, parameters such as pulse transit time (PTT) and BP still have slight fluctuations at rest for each subject. The conventional oPTP method had a strong sensitivity in the selection of initial value. Yet, the initial sensitivity of calibration has not been reported and investigated in cuff-less BP motoring. In this study, a mean point-to-point (mPTP) paring calibration method through averaging and balancing calm or peaceful states was proposed for the first time. Thus, based on mPTP, a factor point-to-point (fPTP) paring calibration method through introducing the penalty factor was further proposed to improve and optimize the performance of BP estimation. Using the oPTP, mPTP, and fPTP methods, a total of more than 100,000 heartbeat samples from 21 healthy subjects were tested and validated in the PTT-based BP monitoring technologies. The results showed that the mPTP and fPTP methods significantly improved the performance of estimating BP compared to the conventional oPTP method. Moreover, the mPTP and fPTP methods could be widely popularized and applied, especially the fPTP method, on estimating cuff-less diastolic blood pressure (DBP). To this extent, the fPTP method weakens the initial calibration sensitivity of cuff-less BP estimation and fills in the ambiguity for individualized calibration procedure

Ellagic Acid–Cyclodextrin Inclusion Complex-Loaded Thiol–Ene Hydrogel with Antioxidant, Antibacterial, and Anti-inflammatory Properties for Wound Healing

Hydrogel dressings not only have basic functions such as swelling, water retention, gas permeability, and good biocompatibility but also can be endowed with advanced functions such as antibacterial, antioxidant, adhesion, hemostasis, and anti-inflammation, which make hydrogels have great application potential in clinical trauma. However, the complexity of the wound healing process makes the development of multifunctional wound dressings a great challenge. In this work, based on the thiol–ene photoclickable PEG hydrogel, the inclusion complex of the hydrophobic drug ellagic acid (EA) with mono-(6-mercapto-6-deoxy)-β-cyclodextrin (SH-β-CD) participated in the formation of a hydrogel as a crosslinker. The drug EA with antioxidant, antibacterial, and anti-inflammatory activities was introduced into the hydrogel. This strategy increases the loading capacity of the hydrogel for EA and endows the hydrogel with multifunctional properties. Then, dithiothreitol was added to adjust the mechanical stiffness of the hydrogel to meet the requirements of the wound dressing. Our results demonstrated that this wound dressing has excellent cytocompatibility, antioxidant, antibacterial, and anti-inflammatory activities. Furthermore, the results of the infected wound healing model experiment in rats confirmed that the hydrogel has the ability to rapidly shrink the wound area, prevent wound infection, and promote angiogenesis and collagen deposition. All these results suggest that this hydrogel could be a candidate for the treatment of infected wounds and shed new light on the development of multifunctional wound dressings

Additional file 1 of RU.521 mitigates subarachnoid hemorrhage-induced brain injury via regulating microglial polarization and neuroinflammation mediated by the cGAS/STING/NF-κB pathway

Additional file 1: Supplementary Figure S1. Experimental design and groups. SAH, subarachnoid hemorrhage; WB, western blot; IF, immunofluorescence; RU.521, selective small molecule inhibitor for cGAS; Vehicle, 1% DMSO + corn oil; TUNEL: terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling; MWM, Morris water maze; 2’3’-cGAMP, a second messenger converted by activated cGAS; PBS, phosphate-buffered saline; Oxy-Hb, oxyhemoglobin; Annexin V-FITC, Annexin V-FITC Apoptosis Detection Kit; CCK-8, Cell Counting Kit-8. The figure was created with Biorender.com. Agreement number: HV25N2UEYC. Supplementary Figure S2. Representative images for brain tissues and SAH grading scores for each group. (A) This figure displayed representative brain images for sham (left) and SAH (right) conditions in rats, where the SAH image showed blood clots in the subarachnoid space. Additionally, an illustration of six parts on the ventral surface of the brain after SAH in rats was presented on the right. (B) The SAH grading scores for each group 24 h after SAH was shown in panel B. *: P < 0.05 vs. Sham. Vehicle, 1% DMSO + corn oil; PBS, phosphate-buffered saline. Supplementary Table S1. The grading system for SAH. Supplementary Table S2. Modified Garcia score. Supplementary Table S3. Beam balance test. Supplementary Table S4. Antibodies used in this study. Supplementary Table S5. Distribution of animals according to different groups and mortality rate

The protein expressions of HIF-1α, VEGF, VEGFR and a series of inflammatory factors based on HIF-1α polymorphisms.

<p>Figure 2 shows that only the 1790A>G polymorphism significantly affects the expression level of HIF-1α, VEGF, VEGFR, IL1, IL6 and NF-kB protein expressions compared to 1970AA and 1970AG. The OPG and OPN levels were not changed when stratified by 1790A>G polymorphism (Figure 2). The 1772C>T genotype did not influence the above mentioned factors expression levels.</p

The genotype and allele frequencies of HIF-1α polymorphism in CSM and control subjects.

<p>The genotype and allele frequencies of HIF-1α polymorphism in CSM and control subjects.</p

Characteristics of subjects.

<p>Characteristics of subjects.</p