Measurement of Vital Signs Using Lifelight Remote Photoplethysmography: Results of the VISION-D and VISION-V Observational Studies.

BACKGROUND: The detection of early changes in vital signs (VSs) enables timely intervention; however, the measurement of VSs requires hands-on technical expertise and is often time-consuming. The contactless measurement of VSs is beneficial to prevent infection, such as during the COVID-19 pandemic. Lifelight is a novel software being developed to measure VSs by remote photoplethysmography based on video captures of the face via the integral camera on mobile phones and tablets. We report two early studies in the development of Lifelight. OBJECTIVE: The objective of the Vital Sign Comparison Between Lifelight and Standard of Care: Development (VISION-D) study (NCT04763746) was to measure respiratory rate (RR), pulse rate (PR), and blood pressure (BP) simultaneously by using the current standard of care manual methods and the Lifelight software to iteratively refine the software algorithms. The objective of the Vital Sign Comparison Between Lifelight and Standard of Care: Validation (VISION-V) study (NCT03998098) was to validate the use of Lifelight software to accurately measure VSs. METHODS: BP, PR, and RR were measured simultaneously using Lifelight, a sphygmomanometer (BP and PR), and the manual counting of RR. Accuracy performance targets for each VS were defined from a systematic literature review of the performance of state-of-the-art VSs technologies. RESULTS: The VISION-D data set (17,233 measurements from 8585 participants) met the accuracy targets for RR (mean error 0.3, SD 3.6 vs target mean error 2.3, SD 5.0; n=7462), PR (mean error 0.3, SD 4.0 vs mean error 2.2, SD 9.2; n=10,214), and diastolic BP (mean error -0.4, SD 8.5 vs mean error 5.5, SD 8.9; n=8951); for systolic BP, the mean error target was met but not the SD (mean error 3.5, SD 16.8 vs mean error 6.7, SD 15.3; n=9233). Fitzpatrick skin type did not affect accuracy. The VISION-V data set (679 measurements from 127 participants) met all the standards: mean error -0.1, SD 3.4 for RR; mean error 1.4, SD 3.8 for PR; mean error 2.8, SD 14.5 for systolic BP; and mean error -0.3, SD 7.0 for diastolic BP. CONCLUSIONS: At this early stage in development, Lifelight demonstrates sufficient accuracy in the measurement of VSs to support certification for a Level 1 Conformité Européenne mark. As the use of Lifelight does not require specific training or equipment, the software is potentially useful for the contactless measurement of VSs by nonclinical staff in residential and home care settings. Work is continuing to enhance data collection and processing to achieve the robustness and accuracy required for routine clinical use. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/14326.

Clinical features of central isolated unilateral foot drop: A case report and review of the literature.

BACKGROUND: Intracranial cause of isolated unilateral foot drop is very rare. There may be a delay in the diagnosis of the cause of central foot drop or patients with such lesions might be misdiagnosed and subjected to unnecessary interventions. One of the reasons for the diagnostic uncertainty might be the absence of upper motor neuron (UMN) signs in the initial examination of such patients. CASE DESCRIPTION: We present a very rare case of a 78-year-old woman who had presented with a five-year progressive right-sided unilateral isolated foot drop from a left-sided parasagittal tumor. Previously, she had undergone biopsy of an abnormality on the right C7/T1 facet, which was found to be benign. On examination of the patient, she had UMN signs in the ipsilateral foot. On magnetic resonance imaging scan of her head, a 3-cm left parasagittal lesion, consistent with it being a meningioma, was noted. The patient had significant medical history and declined to undergo surgical removal of the lesion. CONCLUSION: We review the literature on central foot drop from various intracranial pathologies and discern its clinical features. Patients with central foot drop often have UMN signs; however, these may be absent causing diagnostic uncertainty, and physicians should be vigilant of these variations in the presentation.

Tumefactive demyelination-an unusual neurological presentation of HIV.

We describe 3 individuals infected with human immunodeficiency virus with unusual focal brain syndromes; magnetic resonance imaging revealed "open-ring" pattern space occupying lesions. After deterioration while the patients were receiving anti-Toxoplasma therapy, brain biopsy was performed, which revealed aggressive demyelination consistent with tumefactive demyelination. Treatment with high-dose steroids resulted in complete recovery in all cases.

Attitudes to the use of prophylaxis for thrombo-embolism in neurosurgical patients.

Neurosurgical patients are at significant risk of thromboembolic complications. A survey of 58 consultant neurosurgeons in United Kingdom confirmed that 84.5% regularly used some form of prophylaxis. For all forms of neurosurgery, the most preferred method of prophylaxis was mechanical (graduated compression stockings-TEDS and intra-operative pneumatic calf compressors-IPC) or in the post-operative period a combination of mechanical methods and low molecular weight heparin (LMWH). LMWH was rarely administered in the perioperative period. The majority of neurosurgeons believed that TEDS and LMWH reduced post-operative DVT (79% and 90%, respectively) and PE (43% and 67%), but 29% associated LMWH with bleeding complications. A review of current literature revealed that TEDS, IPC, and LMWH are effective in reducing the incidence of DVT, but the evidence over the safety of heparin is inconclusive in neurosurgical patients. There is still room for improvement as a minority of neurosurgeons continue to ignore the importance of prophylaxis against thrombo-embolism in neurosurgery.