Skin-interfacing wearable biosensors for smart health monitoring of infants and neonates

Health monitoring of infant patients in intensive care can be especially strenuous for both the patient and their caregiver, as testing setups involve a tangle of electrodes, probes, and catheters that keep the patient bedridden. This has typically involved expensive and imposing machines, to track physiological metrics such as heart rate, respiration rate, temperature, blood oxygen saturation, blood pressure, and ion concentrations. However, in the past couple of decades, research advancements have propelled a world of soft, wearable, and non-invasive systems to supersede current practices. This paper summarizes the latest advancements in neonatal wearable systems and the different approaches to each branch of physiological monitoring, with an emphasis on smart skin-interfaced wearables. Weaknesses and shortfalls are also addressed, with some guidelines provided to help drive the further research needed.

Neurological injury in pediatric heart disease: A review of developmental and acquired risk factors and management considerations

Medical and surgical advancements have improved survival in children with acquired and congenital heart disease (CHD), but the burden of neurological morbidity is high. Brain disorders associated with CHD include white matter injury, stroke, seizure, and neurodevelopmental delays. While genetics and disease-specific factors play a substantial role in early brain injury, therapeutic management of the heart disease intensifies the risk. There is a growing interest in understanding how to reduce brain injury and improve neurodevelopmental outcomes in cardiac diseases. Pediatric neurologists serve a vital role in care teams managing these complex patients, providing interpretation of neuromonitoring and imaging, managing neurologic emergencies, assisting with neuro prognostication, and identifying future research aims.

Carbon dioxide and cardiac output as major contributors to cerebral oxygenation during apnoeic oxygenation

Apnoeic oxygenation has experienced a resurgence in interest in critical care and perioperative medicine. However, its effect on cerebral oxygenation and factors influencing it, have not yet been investigated in detail. By using near-infrared spectroscopy, we intended to provide further evidence for the safety of apnoeic oxygenation and to increase our understanding of the association between cerebral perfusion, haemodynamic, respiratory and demographic factors. In this secondary analysis of a prospective randomized controlled noninferiority trial, we recruited 125 patients, who underwent surgery under general anaesthesia with neuromuscular blockade. Arterial blood samples were taken every 2 min for a total of 15 min under apnoeic oxygenation with 100% oxygen. Near-infrared spectroscopy and cardiac output were continuously measured. Statistical analysis was performed using uni- and multivariable statistics. Ninety-one complete data sets were analysed. In six patients the SpO2 fell below 92% (predefined study termination criterion). The significant average increase of cerebral oxygenation was 0.5%/min and 2.1 mmHg/min for the arterial pressure of carbon dioxide (paCO2). The median cardiac output increased significantly from 5.0 l/min (IQR 4.5-6.0) to 6.5 l/min (IQR 5.7-7.5). The most significant effect on cerebral oxygenation was exhibited by the variable paCO2 and non-specific patient factors, followed by cardiac output and paO2. Apnoeic oxygenation proves to have a high safety profile while significantly increasing cerebral oxygenation, paCO2 and cardiac output. In reverse, NIRS might act as a reliable clinical surrogate of paCO2 and cardiac output during stable arterial oxygenation.

Cerebral Near-Infrared Spectroscopy: A Viable Tool in an Anesthesiologist's Armamentarium for Pediatric Head and Neck Surgeries

Near-infrared spectroscopy (NIRS) is a noninvasive monitor used regularly in pediatric cardiac surgeries to monitor regional cerebral oxygenation (rScO2). A significant intraoperative cerebral desaturation (>20% from baseline) has been reported with poor neurological outcomes. We describe a case of a six-year-old child with carotid sheath neuroblastoma, located at the carotid bifurcation posted for tumor excision. Intraoperative NIRS monitoring revealed only a transient and insignificant (<10%) fall in the rScO2 during the tumor manipulation, ensuring uninterrupted cerebral circulation. The pediatric population is vulnerable to various physiological changes during anesthesia and surgery, and conserving cerebral function is one of the major goals. Though NIRS has been researched in various surgical specialties, future emphasis must be laid on its use in pediatric head and neck surgeries as a surrogate for cerebral perfusion.

Cardiac output monitoring in children: a review

Cardiac output monitoring enables physiology-directed management of critically ill children and aids in the early detection of clinical deterioration. Multiple invasive techniques have been developed and have demonstrated ability to improve clinical outcomes. However, all require invasive arterial or venous catheters, with associated risks of infection, thrombosis and vascular injury. Non-invasive monitoring of cardiac output and fluid responsiveness in infants and children is an active area of interest and several proven techniques are available. Novel non-invasive cardiac output monitors offer a promising alternative to echocardiography and have proven their ability to influence clinical practice. Assessment of perfusion remains a challenge; however, technologies such as near-infrared spectroscopy and photoplethysmography may prove valuable clinical adjuncts in the future.

The critical role of technologies in neonatal care

Neonatal care has made significant advances in the last few decades. As a result, mortality and morbidity in high-risk infants, such as extremely preterm infants or those infants with birth-related brain injury, has reduced significantly. Many of these advances have been facilitated or delivered through development of medical technologies allowing clinical teams to be better supported with the care they deliver or provide new therapies and diagnostics to improve management. The delivery of neonatal intensive care requires the provision of medical technologies that are easy to use, reliable, accurate and ideally developed for the unique needs of the newborn population. Many technologies have been developed and commercialised following adult trials without ever being studied in neonatal patients despite the unique characteristics of this population. Increasingly, funders and industry are recognising this major challenge which has resulted in initiatives to develop new ideas from concept through to clinical care. This review explores some of the key medical technologies used in neonatal care and the evidence to support their adoption to improve outcomes. A number of devices have yet to realise their full potential and will require further development to optimise and find their ideal target population and clinical benefit. Examples of emerging technologies, which may soon become more widely used, are also discussed. As neonatal care relies more on medical technologies, we need to be aware of the impact on care pathways, especially from a human factors approach, the associated costs and subsequent benefits to patients alongside the supporting evidence.

Evaluation of the robustness of cerebral oximetry to variations in skin pigmentation using a tissue-simulating phantom

Clinical studies have demonstrated that epidermal pigmentation level can affect cerebral oximetry measurements. To evaluate the robustness of these devices, we have developed a phantom-based test method that includes an epidermis-simulating layer with several melanin concentrations and a 3D-printed cerebrovascular module. Measurements were performed with neonatal, pediatric and adult sensors from two commercial oximeters, where neonatal probes had shorter source-detector separation distances. Referenced blood oxygenation levels ranged from 30 to 90%. Cerebral oximeter outputs exhibited a consistent decrease in saturation level with simulated melanin content; this effect was greatest at low saturation levels, producing a change of up to 15%. Dependence on pigmentation was strongest in a neonatal sensor, possibly due to its high reflectivity. Overall, our findings indicate that a modular channel-array phantom approach can provide a practical tool for assessing the impact of skin pigmentation on cerebral oximeter performance and that modifications to algorithms and/or instrumentation may be needed to mitigate pigmentation bias.

Percutaneous Common Carotid Artery Access for Cardiac Interventions in Infants Does Not Acutely Change Cerebral Perfusion

Pediatric cardiac interventions via percutaneous common carotid artery (CCA) access have been shown to be safe and effective. However, the impact of placement of a sheath in the carotid artery for interventions on cerebral perfusion is unknown. In this study we used cerebral near-infrared spectroscopy (NIRS) to analyze the effects of percutaneous CCA access for cardiac interventions on cerebral perfusion. This study is a retrospective chart review carried out at a tertiary care center on all pediatric patients who underwent percutaneous cardiac catheterization via carotid artery access from January 2010 to January 2020. All patients who had ipsilateral NIRS recorded on the side of carotid artery access were included. Patients with only partial or no ipsilateral NIRS data were excluded. The primary outcome measure was the change in NIRS upon CCA access; the mean NIRS for 15 min before obtaining access was compared to the mean NIRS during the procedure and to the mean NIRS 15 min after removal of the CCA sheath. We hypothesized that there would be a significant drop in NIRS values on the side of CCA access. There were 48 catheterizations in the study period where percutaneous CCA was accessed. Of those, 21 catheterizations had complete data and were included in the study. 13 (62%) were of males. The median age was 23 days (IQR 7-79). The indications for CCA access were patent ductus arteriosus stent implantation (n = 13; 62%), aortic valvuloplasty (n = 5; 24%), balloon angioplasty of coarctation of aorta (n = 2; 10%), and renal artery angioplasty (n = 1; 4%). In 16 patients (72%), the left common carotid artery was accessed. The median weight of the patients was 3.3 kg (IQR 2.8-2.9). The most common sheath size used was 4F, in 16 patients (72%). The mean NIRS prior to the procedure was 67 ± 15%, during the procedure was 68 ± 20%, and after removal of sheath was 68 ± 21%. Paired t test of cerebral NIRS before, during, and after the procedure showed no significant change with CCA access (P = 0.08). No patient in the series had a documented neurologic deficit following the procedure. Percutaneous CCA access was not associated with a decrease in NIRS on the side of the access during the procedure, suggesting there was no significant acute change in cerebral perfusion with CCA access.

Direct postoperative protein S100B and NIRS monitoring in infants after pediatric cardiac surgery enrich early mortality assessment at the PICU

BACKGROUND

Neuromonitoring using plasmatic biomarkers such as S100B and near-infrared spectroscopy (NIRS) represents a standard procedure for detecting cerebral damage after cardiac surgery. Their use in pediatric clinical assessment, however, is negligible.

OBJECTIVES

The goal of this study was to evaluate the predictive role of S100B levels and cerebral oxygenation in postoperative pediatric cardiac patients for survival and potential cerebral injuries.

METHODS

A retrospective cohort study of infants after cardiac surgery. Primary outcome was survival until discharge. Intra/postoperative vital signs and laboratory data were measured and statistically analyzed.

RESULTS

Seven out of 226 infants were non-survivors. Non-survivors had significantly lower cerebral saturation than survivors, as well as elevated S100B values at admission, associated with lower arterial pressure and higher serum lactate levels.

CONCLUSION

Although significant differences of S100B and crO₂ values between survivors and non-survivors were found, no critical thresholds could be established from the data. Nevertheless, changes from the norm in these parameters should raise awareness for critical clinical development.

Cerebral oximetry performance testing with a 3D-printed vascular array phantom

Cerebral oximetry based on near-infrared spectroscopy represents a unique noninvasive tool for real-time surgical monitoring, yet studies have shown a significant discrepancy in accuracy among commercial systems. Towards the establishment of a standardized method for performance testing, we have studied a solid phantom approach - based on a 3D-printed cerebrovascular module (CVM) incorporating an array of 148 cylindrical channels - that has several advantages over liquid phantoms. Development and characterization of a CVM prototype are described, including high-resolution imaging and spectrophotometry measurements. The CVM was filled with whole bovine blood tuned over an oxygen saturation range of 30-90% and molded-silicone layers simulating extracerebral tissues were used to evaluate penetration depth. Saturation measurement accuracy was assessed in two commercially-available clinical cerebral oximeters. For one oximeter, both neonatal and pediatric sensors showed a high degree of precision, whereas accuracy was strongly dependent on saturation level and extracerebral geometry. The second oximeter showed worse precision, yet greater robustness to variations in extracerebral layers. These results indicate that 3D-printed channel array phantoms represent a promising new approach for standardized testing of clinical oximeters.

The State of Technology in Craniosynostosis

INTRODUCTION

Craniosynostosis, the premature fusion of ≥1 cranial sutures, is the leading cause of pediatric skull deformities, affecting 1 of every 2000 to 2500 live births worldwide. Technologies used for the management of craniofacial conditions, specifically in craniosynostosis, have been advancing dramatically. This article highlights the most recent technological advances in craniosynostosis surgery through a systematic review of the literature.

METHODS

A systematic electronic search was performed using the PubMed database. Search terms used were "craniosynostosis" AND "technology" OR "innovation" OR "novel.' Two independent reviewers subsequently reviewed the resultant articles based on strict inclusion and exclusion criteria. Selected manuscripts deemed novel by the senior authors were grouped by procedure categories.

RESULTS

Following review of the PubMed database, 28 of 536 articles were retained. Of the 28 articles, 20 articles consisting of 21 technologies were deemed as being novel by the senior authors. The technologies were categorized as diagnostic imaging (n = 6), surgical planning (n = 4), cranial vault evaluation (n = 4), machine learning (n = 3), ultrasound pinning (n = 3), and near-infrared spectroscopy (n = 1).

CONCLUSION

Multiple technological advances have impacted the treatment of craniosynostosis. These innovations include improvement in diagnosis and objective measurement of craniosynostosis, preoperative planning, intraoperative procedures, communication between both surgeons and patients, and surgical education.