Low delay rate adaptive pacemaker using FPGA embedded piezoelectric sensor

Abstract

This paper presents the hardware implementation of low delay, power-efficient, rate-adaptive dual-chamber pacemaker (RDPM) using a piezoelectric sensor. Rate adaptive pacemaker has the ability to sense the patient’s activity by means of some special sensors and it controls the pacing rate according to the patient’s activity. Ideally, there should be no delay between sensing and the subsequent pacing operation performed by the pacemaker. However, delay in the responses of various components in the circuitry produces an accumulative delay effect in any practical circuit. Physical activity and the physiological needs of the patient can be easily adapted by the rate-responsive pacemakers using a wide range of sensor information. The piezo-electric sensor recognises the pressure on human muscles because of physical activity and converts it to an electrical signal, which is received by the pulse generator of the pacemaker. When the patient is in the rest mode, the heart rate is the only parameter that is to be detected by the pacemaker. Thus, the heart rate and the physical activity both are the inevitable parameters for the design of RDPM. Performance analysis of the proposed RDPM shows a significant reduction in the delay between sensing and pacing. Device utility analysis shows that the proposed design not only requires lesser memory but also reduces the number of components on the chip. Therefore, it becomes very clear that the proposed pacemaker design will consume much lesser power.     

Effects of mTOR inhibitor–related proteinuria on progression of cardiac allograft vasculopathy and outcomes among heart transplant recipients

We have previously described the use of sirolimus (SRL) as primary immunosuppression following heart transplantation (HT). The advantages of this approach include attenuation of cardiac allograft vasculopathy (CAV), improvement in glomerular filtration rate (GFR), and reduced malignancy. However, in some patients SRL may cause significant proteinuria. We sought to investigate the prognostic value of proteinuria after conversion to SRL. CAV progression and adverse clinical events were studied. CAV progression was assessed by measuring the Δ change in plaque volume (PV) and plaque index (PI) per year using coronary intravascular ultrasound. Proteinuria was defined as Δ urine protein ≥300 mg/24 h at 1 year after conversion to SRL. Overall, 137 patients were analyzed (26% with proteinuria). Patients with proteinuria had significantly lower GFR (P = .005) but similar GFR during follow-up. Delta PV (P < .001) and Δ PI (P = .001) were significantly higher among patients with proteinuria after adjustment for baseline characteristics. Multivariate Cox regression analysis showed higher all-cause mortality (hazard ratio 3.8; P = .01) with proteinuria but similar risk of CAV-related events (P = .61). Our results indicate that proteinuria is a marker of baseline renal dysfunction, and that HT recipients who develop proteinuria after conversion to SRL have less attenuation of CAV progression and higher mortality risk.     

Categorisation of ventilatory pattern of response to bronchodilator therapy in airflow limitation

Improvement in lung function studies following bronchodilator inhalation leads to different pattern of response in ventilatory parameters which are helpful in categorizing the patients into groups for correct interpretation of bronchodilator response and assessment of prognosis of the disease.     

Linear Nevus Sebaceus Syndrome with bilateral complex limbal choristomas and extraocular muscle involvement

A case of a child with bilateral fleshy limbal masses with a coloboma of the right upper lid is discussed. Systemic examination revealed two patches of alopecia on the right frontoparietal and right occipital areas of the scalp. Punch biopsy and histopathological examination led to the diagnosis of Linear Nevus Sebaceus Syndrome (LNSS) with bilateral complex limbal choristomas. The authors have stated that they do not have a significant financial interest or other relatioship with any product manufacturer or provider of services discussed in this article. The authors also do not discuss the use of off-label products, which includes unlabeled, unapproved, or investigative products or devices.     

B7-h4 is highly expressed in ductal and lobular breast cancer.

PURPOSE: This study was designed to investigate the expression of B7-H4 protein, a member of the B7 family that is involved in the regulation of antigen-specific immune responses, in normal breast and in primary and metastatic breast carcinomas. EXPERIMENTAL DESIGN: Archival formalin-fixed tissue blocks from breast cancers and normal somatic tissues were evaluated for B7-H4 expression by immunohistochemistry with manual and automated image analysis. The proportion of B7-H4-positive cells and the intensity of B7-H4 staining were compared with histologic type, grade, stage, hormone receptor status, and HER-2/neu status. RESULTS: B7-H4 was detected in 165 of 173 (95.4%) primary breast cancers and in 240 of 246 (97.6%) metastatic breast cancers. B7-H4 staining intensity was greater in invasive ductal carcinomas [24.61 relative units (RU)] and in invasive lobular carcinomas (15.23 RU) than in normal breast epithelium (4.30 RU, P = 0.0003). Increased staining intensity was associated with negative progesterone receptor status (P = 0.014) and history of neoadjuvant chemotherapy (P = 0.004), and the proportion of B7-H4-positive cells was associated with negative progesterone receptor (P = 0.001) and negative HER-2/neu (P = 0.024) status. However, there was no statistically significant relationship between the proportion of B7-H4-positive cells or staining intensity and grade, stage, or other clinicopathologic variables. Low levels of B7-H4 expression were also detected in epithelial cells of the female genital tract, lung, pancreas, and kidney, but B7-H4 was generally absent in most other normal somatic tissues. CONCLUSIONS: The nearly ubiquitous expression of B7-H4 in breast cancer, independent of tumor grade or stage, suggests a critical role for this protein in breast cancer biology.     

COVID-19-associated mucormycosis and treatments

In the current pandemic, COVID-19 patients with predisposing factors are at an increased risk of mucormycosis, an uncommon angioinvasive infection that is caused by fungi with Mucor genus which is mainly found in plants and soil. Mucormycosis development in COVID-19 patient is related to various factors, such as diabetes, immunocompromise and neutropenia. Excessive use of glucocorticoids for the treatment of critically ill COVID-19 patients also leads to opportunistic infections, such as pulmonary aspergillosis. COVID-19 patients with mucormycosis have a very high mortality rate. This review describes the pathogenesis and various treatment approaches for mucormycosis in COVID-19 patients, including medicinal plants, conventional therapies, adjunct and combination therapies.