Developing a Fiber Optic Magnetic Field Sensor: Fiber Bragg Gratings and the Magnetorefractive Effect

Optical fiber Bragg gratings (FBGs) have been shown to provide sensing of strain and temperature at 100's of points along a fiber's path. This work extended that to 1000's of points, and added discrete sensing of magnetic field along the fiber. The first was achieved via an extension of the optical frequency domain reflectometery (OFDR) de-multiplexing method. This was done by treating FBG segments as a series of concatenated FBGs instead of one discrete FBG. Such treatment allows for the resolution of even a micro-crack's strain fields in a pressurized composite overwrapped pressure vessel (COPV), which are on the 0.5 mm scale. The second advancement of FBGs, magnetic sensing, was added via an assembly to transduce magnetic attraction into fiber strain. This assembly allowed multiplexed magnetically sensitive FBG sensors for the first time. Stringing pieces of magnetic material onto a fiber and gluing that fiber onto a structure is an easy method and largely uses off-the-shelf components. This will prove simple to expand and utilize to solve actual engineering problems. To further improve, by removing the strain transduction and thus reduce vibrational sensitivity, a new magneto-optical material is needed. An investigation into the magnetorefractive effect (MRE), and characterization of the shift of index of refraction in the material La1-xSrxMnO3 (LSMO) with magnetic field and temperature was performed. The index of refraction of the LSMO was found to shift with magnetic field. This was leveraged to create a magnetometer interferometer. That device did not function though, as the absorption of the magneto-optic LSMO used prevented light's transmission through that active material. This highlights the complex, i.e. non-real, index of refraction of LSMO an aspect which would warrant further investigation

Incision Precision of a Novel Wire-Guided Scalpel During Central Venous Catheter Placement: A Randomized Observational Trial.

ObjectiveTo determine whether the wire-guided scalpel (GuideBlade) improves incision precision, reduces the need to revise dermatotomy incision, improves the first-time success rate of a central venous catheter (CVC) placement, and decreases CVC-related complications.DesignA randomized 2-arm observational trial.SettingAt University of California Irvine Medical Center.ParticipantsPatients (n = 63) undergoing surgery requiring placement of a CVC as part of the standard of care recruited from August 1, 2021, to December 31, 2021.InterventionsAfter randomization, either the GuideBlade (intervention) or the standard #11 scalpel (control) was used during CVC placement before surgery.Measurements and main resultsThe number of dermatotomy attempts was higher using the GuideBlade (1.6 ± 1.0) compared to the standard #11 scalpel (1.4 ± 0.6); however, the difference did not reach statistical significance (p = 0.19). Similarly, the number of dilation attempts demonstrated no significant difference between the GuideBlade (1.2 ± 0.4) and the standard scalpel (1.1 ± 0.4; p = 0.65). No CVC-related infections or complications were documented.ConclusionsNo superiority was observed with using the GuideBlade compared to the standard scalpel during central line insertion by novice users. User unfamiliarity and inadequate training may have contributed to this finding, highlighting the importance of proper technique and user experience

Breastfeeding in the Neonatal Intensive Care Unit (NICU): Surveying OT Practices

Abstract Date Presented 04/05/19 This study aimed to explore if and how OTs are addressing breastfeeding in the NICU, including the types of interventions used, the roles assumed, and subjective perceptions of barriers to addressing breastfeeding. An online survey was distributed nationwide to OTs currently working in NICUs. Data were collected from 85 eligible participants in 30 states; 84% of respondents indicated they provide breastfeeding interventions primarily in the roles of clinician and educator. Primary Author and Speaker: Allison Smith Additional Authors and Speakers: Erin Kastelz, Alexandra Moini, Erica Strutner, Eric Ingersoll Contributing Authors: Jim Le</jats:p

Heart Rate Variation is The Clinical Sign Associated with The Deepest Plane of Anesthesia During Induction: The Novel Finding and Its Clinical Implications

Background: Premature airway manipulation during induction can lead to adverse patient outcomes. However, there is currently no standardized clinical sign to assess adequate anesthesia depth during induction. With the goal of increasing patient safety during induction, we aim to correlate different clinical signs during induction with the depth of anesthesia using the bispectral index (BIS) monitor and determine the physical metrics corresponding to the deepest plane of anesthesia. Methodology: This prospective study enrolled 41 subjects scheduled for surgery requiring propofol for induction. A BIS monitor was used for standardized monitoring of anesthesia depth during the induction process. We documented the BIS value and occurrence time of the observed physical metrics: (1) loss of eyelash reflex, (2) loss of response to verbal stimuli, (3) loss of muscle tone, (4) loss of end tidal carbon dioxide (EtCO2) or apnea, and (5) transient heart rate variations. Results: Apnea, change in heart rate from baseline, and heart rate return to baseline are signs during induction associated with both lower BIS values and later occurrence when compared to other clinical signs such as loss of eyelash reflex, verbal response, and muscle tone (P &lt; 0.001). Conclusion: Physical signs such as loss of eyelash reflex, verbal response, and muscle tone during induction are associated to lighter planes of anesthesia. A safer and deeper plane of anesthesia occurs later. Relying on these physical signs for assessment of laryngeal mask airway insertion may increase the risk of stimulating the patient’s airway prematurely, which can lead to adverse patient outcomes

Withdrawn as duplicate: Comparison of RT-PCR Cycle Threshold Values from Respiratory Specimens in Symptomatic and Asymptomatic Children with SARS-CoV-2 Infection

Abstract This article was erroneously published under a new DOI, and is a duplicate of [Comparison of Reverse-Transcription Polymerase Chain Reaction Cycle Threshold Values From Respiratory Specimens in Symptomatic and Asymptomatic Children With Severe Acute Respiratory Syndrome Coronavirus 2 Infection; Strutner J, Ramchandar N, Dubey S et al.], originally published at https://doi.org/10.1093/cid/ciab120. The version of record for this article is available in full at the DOI link above and in Volume 73, Issue 10 of Clinical Infectious Diseases: https://academic.oup.com/cid/issue/73/10. The Publisher apologizes for any inconvenience.</jats:p

#27: Comparison of RT-PCR Cycle Threshold Values from Respiratory Specimens in Symptomatic and Asymptomatic Children with SARS CoV-2 Infection

Abstract Background Understanding viral kinetics of SARS-CoV-2 is important to assess risk of transmission, manage treatment, and determine the need for isolation and protective equipment. Children have been noted to have less severe illness than adults and may have less transmission potential. We sought to determine whether children deemed to be asymptomatic had a difference in the PCR cycle threshold (Ct) value of respiratory samples from symptomatic children with SARS CoV-2 infection. Methods This was a retrospective cross-sectional study to compare PCR Ct values of 728 children who tested positive for SARS-CoV-2 by respiratory samples collected over a 4-month period. The study was a single center review of patients who tested positive for SARS-CoV-2 by RT-PCR from a respiratory specimen at a large tertiary care children’s hospital. Inclusion criteria included children 0–18 years of age who tested positive for SARS-CoV-2 by RT-PCR from a respiratory specimen for whom clinical information was available in the electronic medical record. Results We analyzed 728 children who tested positive for SARS-CoV-2 by RT-PCR from a respiratory sample over a 4-month period and for whom data was available in the electronic medical record. Overall, 71.2% of infected children were symptomatic. The mean Ct value for symptomatic patients (Ct mean 19.9, SD 6.3) was significantly lower than asymptomatic patients (Ct mean 23.5, SD 6.5) (P value &amp;lt; 0.001, CI95th 2.6 - 4.6). The mean PCR Ct value was lowest in children less than 5 years of age. Conclusions and Relevance In this retrospective review of children who tested positive by RT-PCR for SARS CoV-2, the mean Ct was significantly lower in symptomatic children and was lowest in children under 5 years of age. </jats:sec