Single Center First Year Experience And Outcomes With Impella 5.5 Left Ventricular Assist Device

BackgroundThe Impella 5.5® was approved by the FDA for use for mechanical circulatory support up to 14 days in late 2019 at limited centers in the United States. Our single center’s experience with Impella 5.5® can expand the overall understanding for achieving successful patient outcomes as well as provide support for the expansion of its FDA-approved use.Methods This study is an IRB-approved single-center retrospective cohort analysis of hospitalized adult patient characteristics and outcomes in cases where the Impella 5.5® was utilized for mechanical circulatory support.Results A total of 26 implanted Impella 5.5® devices were identified in 24 hospitalized patients at our institution from January 2020 to January 2021. The overall survival rate during index hospitalization was 75%. Eleven Impella 5.5® devices were identified in 10 patients with an average device implantation greater than 14 days. Average device implantation for this subgroup was 27 days with a range of 15-80 days. Survival rate for Impella 5.5® use greater than 14 days was 67%. In the entire cohort and subgroup of device implantation >14 days, evidence of end organ damage improved with Impella 5.5® use. Complications in our cohort and subgroup of device implantation >14 days were similar to previously reported complication incidence of axillary inserted LVAD devices. Conclusions Our institution’s experience with the Impella 5.5® has been strongly positive with favorable outcomes and helps to establish the Impella 5.5® as a viable option for mechanical circulatory support beyond 14 days.

Multidevice Cooling With Flow Boiling in a Variable Microgap

Flow boiling in an onboard variable microgap is demonstrated as a viable cooling method for multidevice electronics. The microgap is created by a bonded conformal encapsulation that delivers uniform subcooled inlet coolant flow across a multidevice layout comprising a processor and two in-line, symmetrically placed memory devices. Each device is simulated with a ceramic resistance heater on a 1:1 scale, and the heights of the devices create the variable microgap under the roof line of the encapsulation. The gap height for the processor is 0.5 mm and 1 mm for the memory devices. Parameters investigated are pressure drop, average device temperature, processor power, and coefficient of performance (COP). For inlet coolant flow first over the memory devices, the average device temperature exceeds the 95 °C limit when processor power is ∼50 W or less. For inlet flow over the processor, memory device temperatures are approximately the same over all the levels of processor and memory chip power. For processor power <30 W and an inlet coolant temperature of 25 °C, single-phase heat transfer is the dominant cooling mechanism. When processor power is >40 W, two-phase heat transfer dominates, and processor power of 120 W is reached within the 95 °C threshold. Volumetric power density across the data set is 134 to 1209 W/cm3.

Evaluation of Patient Satisfaction with Different Hearing Aids: A Study of 107 Patients

We retrospectively investigated patient satisfaction with different types of hearing aids in 107 patients—60 males and 47 females, aged 8 to 84 years (mean: 53.8)—with unilateral or bilateral hearing loss, each of whom used two different hearing devices for at least 3 years per device. The International Outcome Inventory for Hearing Aids, Turkish edition (IOI-HA-TR) was used to evaluate satisfaction levels; we also calculated our own total individual subjective satisfaction (TISS) scores. We divided 16 different hearing devices into two types: device 1 and device 2; on average, device 2 had more channels, a lower minimum frequency, and a higher maximum frequency. We found that the IOI-HA-TR scores and TISS scores were higher and usage time was greater during device 2 use, and that there was a positive correlation between IOI-HA-TR and TISS scores. A total of 69 patients (64.5%) used device 2 for more than 8 hours per day, while 38 patients (35.5%) used it for 4 to 8 hours per day during the final 2 weeks of the trial. In contrast, 40 patients (37.4%) used device 1 for more than 8 hours, 50 (46.7%) used it for 4 to 8 hours, and the remaining 17 (15.9%) used it for less than 4 hours; the difference in the duration of use of the two devices was statistically significant (p < 0.001). Younger patients and patients with more education were more satisfied with their devices than were older patients and those who were not as well educated. We conclude that devices with good technologic features such as more channels, a lower minimum frequency, and a higher maximum frequency result in better hearing. Also, based on the age difference that we observed, we recommend that psychological support be provided to older patients with aided hearing to enhance their mental health and quality of life.

Investigating the Humidity Effect on Si/PEDOT:PSS Hybrid Solar Cell and Power Conversion Efficiency Recovery by Re-Deposition of the Hole Transporting Layer

The degradation of silicon nanostructure / poly(3,4-ethylenedioxylthiophene : poly(styrenesulphonic acid) (SiNS/PEDOT:PSS) hybrid solar cell due to the moisture is investigated with an environmental chamber. The unencapsulated devices were tested under different relative humidity (RH) varied from (15% to 100%). Under different RH, the devices show various degradation trends. After 3hrs of storage under 100% RH, the average device power conversion efficiency (PCE) drops from 6.52% to 1.27%. While the device is stored under 15% RH, the averaged PCE just drop from 6.40% to 5.49% and the device at 60% RH degrades from 5.97% to 3.12%. To understand the cause of the device degradation, we compare the ITO conductivity and apply tunneling electron microscopy (TEM) to study the growth of the silicon dioxide layer on the silicon nanostructures. We confirmed that the major cause of the PCE drop in the current devices are due to the decrease of the PEDOT:PSS conductivity and the increase of the interface resistances. By re-depositing the PEDOT:PSS layer onto the degraded device and recycling the Si (and fresh ITO), we demonstrated that the efficiency of the device can be partially recovered (to fully recovered). The current work not only highlighted the importance of the humidity control in these SiNS/PEDOT:PSS hybrid solar cells, but also identified the major causes of the device degradation. The observation has been re-confirmed by recovering the PCE of the degraded device with a fresh PEDOT:PSS layer and a fresh ITO.