Evolution of a System to Monitor Infant Neuromotor Development in the Home: Lessons from COVID-19.

In the nine months leading up to COVID-19, our biomedical engineering research group was in the very early stages of development and in-home testing of HUGS, the Hand Use and Grasp Sensor (HUGS) system. HUGS was conceived as a tool to allay parents' anxiety by empowering them to monitor their infants' neuromotor development at home. System focus was on the evolving patterns of hand grasp and general upper extremity movement, over time, in the naturalistic environment of the home, through analysis of data captured from force-sensor-embedded toys and 3D video as the baby played. By the end of March, 2020, as the COVID-19 pandemic accelerated and global lockdown ensued, home visits were no longer possible and HUGS system testing ground to an abrupt halt. In the spring of 2021, still under lockdown, we were able to resume recruitment and in-home testing with HUGS-2, a system whose key requirement was that it be contactless. Participating families managed the set up and use of HUGS-2, supported by a detailed library of video materials and virtual interaction with the HUGS team for training and troubleshooting over Zoom. Like the positive/negative poles of experience reported by new parents under the isolation mandated to combat the pandemic, HUGS research was both impeded and accelerated by having to rely solely on distance interactions to support parents, troubleshoot equipment, and securely transmit data. The objective of this current report is to chronicle the evolution of HUGS. We describe a system whose design and development straddle the pre- and post-pandemic worlds of family-centered health technology design. We identify and classify the clinical approaches to infant screening that predominated in the pre-COVID-19 milieu and describe how these procedural frameworks relate to the family-centered conceptualization of HUGS. We describe how working exclusively through the proxy of parents revealed the family's priorities and goals for child interaction and surfaced HUGS design shortcomings that were not evident in researcher-managed, in-home testing prior to the pandemic.

Characterization of Infants' General Movements Using a Commercial RGB-Depth Sensor and a Deep Neural Network Tracking Processing Tool: An Exploratory Study.

Cerebral palsy, the most common childhood neuromotor disorder, is often diagnosed through visual assessment of general movements (GM) in infancy. This skill requires extensive training and is thus difficult to implement on a large scale. Automated analysis of GM performed using low-cost instrumentation in the home may be used to estimate quantitative metrics predictive of movement disorders. This study explored if infants' GM may be successfully evaluated in a familiar environment by processing the 3D trajectories of points of interest (PoI) obtained from recordings of a single commercial RGB-D sensor. The RGB videos were processed using an open-source markerless motion tracking method which allowed the estimation of the 2D trajectories of the selected PoI and a purposely developed method which allowed the reconstruction of their 3D trajectories making use of the data recorded with the depth sensor. Eight infants' GM were recorded in the home at 3, 4, and 5 months of age. Eight GM metrics proposed in the literature in addition to a novel metric were estimated from the PoI trajectories at each timepoint. A pediatric neurologist and physiatrist provided an overall clinical evaluation from infants' video. Subsequently, a comparison between metrics and clinical evaluation was performed. The results demonstrated that GM metrics may be meaningfully estimated and potentially used for early identification of movement disorders.

Hand Use and Grasp Sensor System in Monitoring Infant Fine Motor Development.

Objective: To assess the feasibility of a hand use and grasp sensor system in collecting and quantifying fine motor development longitudinally in an infant's home environment. Design: Cohort study. Researchers made home visits monthly to participating families to collect grasp data from infants using a hand use and grasp sensor. Setting: Data collection were conducted in each participant's home. Participants: A convenience sample of 14 typical developmental infants were enrolled from 3 months to 9 months of age. Two infants dropped out. A total of 62 testing sessions involving 12 infants were available for analysis (N=12). Interventions: At each session, the infant was seated in a standardized infant seat. Each instrumented toy was hung on the hand use and grasp sensor structure, presented for 6 minutes in 3 feedback modes: visual, auditory, and vibratory. Main Outcome Measures: Infant grasp frequency and duration, peak grasping force, average grasping force, force coefficient of variation, and proportion of bimanual grasps. Results: A total of 2832 recorded grasp events from 12 infants were analyzed. In linear mixed-effects model analysis, when interacting with each toy, infants' peak grasp force, average grasp force, and accumulated grasp time all increased significantly with age (all P<.001). Bimanual grasps also occupied an increasingly greater percentage of infants' total grasps as they grew older (bar toy P<.001, candy toy P=.021). Conclusions: We observed significant changes in hand use and grasp sensor outcome measures with age that are consistent with maturation of grasp skills. We envision the evolution of hand use and grasp sensor technology into an inexpensive and convenient tool to track infant grasp development for early detection of possible developmental delay and/or cerebral palsy as a supplement to clinical evaluations.

Bis-tridentate IrIII Phosphors Bearing Two Fused Five-Six-Membered Metallacycles: A Strategy to Improved Photostability of Blue Emitters.

Iridium complexes bearing chelating cyclometalates are popular choices as dopant emitters in the fabrication of organic light-emitting diodes (OLEDs). In this contribution, we report a series of blue-emitting, bis-tridentate IrIII complexes bearing chelates with two fused five-six-membered metallacycles, which are in sharp contrast to the traditional designs of tridentate chelates that form the alternative, fused five-five metallacycles. Five IrIII complexes, Px-21-23, Cz-4, and Cz-5, have been synthesized that contain a coordinated dicarbene pincer chelate incorporating a methylene spacer and a dianionic chromophoric chelate possessing either a phenoxy or carbazolyl appendage to tune the coordination arrangement. All these tridentate chelates afford peripheral ligand-metal-ligand bite angles of 166-170°, which are larger than the typical bite angle of 153-155° observed for their five-five-coordinated tridentate counterparts, thereby leading to reduced geometrical distortion in the octahedral frameworks. Photophysical measurements and TD-DFT studies verified the inherent transition characteristics that give rise to high emission efficiency, and photodegradation experiments confirmed the improved stability in comparison with the benchmark fac-[Ir(ppy)3 ] in degassed toluene at room temperature. Phosphorescent OLED devices were also fabricated, among which the carbazolyl-functionalized emitter Cz-5 exhibited the best performance among all the studied bis-tridentate phosphors, showing a maximum external quantum efficiency (EQEmax ) of 18.7 % and CIEx,y coordinates of (0.145, 0.218), with a slightly reduced EQE of 13.7 % at 100 cd m-2 due to efficiency roll-off.

Bis-Tridentate Iridium(III) Phosphors with Very High Photostability and Fabrication of Blue-Emitting OLEDs.

Sky-blue and blue-emitting, carbazolyl functionalized, bis-tridentate Ir(III) phosphors Cz-1-Cz-3 with bright emission and short radiative lifetime are successfully synthesized in a one-pot manner. They exhibit very high photostability against UV-vis irradiation in degassed toluene, versus both green and true-blue-emitting reference compounds, i.e., fac-[Ir(ppy)3] and mer-[Ir(pmp)3]. Organic light-emitting diodes (OLEDs) based on Cz-2 exhibit maximum external quantum efficiency (EQE) of 21.6%, EQE of 15.1% at 100 cd m-2, and with CIE x,y coordinates of (0.17, 0.25). This study provides a conceptual solution to the exceedingly stable and efficient blue phosphor. It is promising that long lifespan blue OLED based on these emitters can be attained with further engineering of devices suitable for commercial application.

Bis-Tridentate Ir(III) Metal Phosphors for Efficient Deep-Blue Organic Light-Emitting Diodes.

Emissive Ir(III) metal complexes possessing two tridentate chelates (bis-tridentate) are known to be more robust compared to those with three bidentate chelates (tris-bidentate). Here, the deep-blue-emitting, bis-tridentate Ir(III) metal phosphors bearing both the dicarbene pincer ancillary such as 2,6-diimidazolylidene benzene and the 6-pyrazolyl-2-phenoxylpyridine chromophoric chelate are synthesized. A deep-blue organic light-emitting diode from one phosphor exhibits Commission Internationale de l'Eclairage (CIE(x,y) ) coordinates of (0.15, 0.17) with maximum external quantum efficiency (max. EQE) of 20.7% and EQE = 14.6% at the practical brightness of 100 cd m-2 .