Dynamic light scattering detector skin#

This study aimed to assess the potential of DLS for HR detection in infants, by evaluating the signal quality of the DLS measurements and determining agreement with ECG. Furthermore, DLS is an optical measurement technique, minimizing the effects of electrical interference. As the signal quality of the DLS technique depends entirely on hemoglobin motion, the pulsatile signal is high even in small premature infants. This is the first study to evaluate the potential of HR detection with DLS. In previous studies, various DLS parameters were evaluated in animals and adult patients.

The DLS HR is calculated from the spectrum analysis of the velocity wave. This enables the DLS technique to measure multiple hemodynamic parameters such as HR and, potentially, blood flow. The speckle pattern is analyzed in real time and provides information about, for example, the speed and size of hemoglobin particles, and translates this to a pulsatile flow waveform. Light scatters off moving hemoglobin, creating a time-varying speckle pattern. Hemoglobin motion is detected with a laser diode which emits a narrow light beam. Recently, a new miniaturized sensor has been developed, allowing noninvasive monitoring of hemodynamic parameters through dynamic light scattering (DLS).

Dynamic light scattering detector skin#

Movement and the small size of the infant, together with a low or small signal amplitude, electrical interference, and the need for limiting the number of adhesives applied to the infant to prevent skin lesions, offer opportunities for new technologies. However, both technologies have their limitations. In infants, HR is closely correlated to cardiac output because their physiology permits only limited stroke volume variation, emphasizing the importance of neonatal HR monitoring.Įlectrocardiography (ECG), the current gold standard, and pulse oximetry are widely used for noninvasive HR monitoring in the neonatal intensive care unit (NICU). To prevent serious complications, adequate and accurate monitoring is mandatory. Drops in heart rate (HR) cause a potentially harmful decrease in cardiac output and related hypoxia, requiring timely intervention. Premature infants are known to experience frequent episodes of bradycardia and apnea. In this study population, specific measurement sites provided excellent signal quality and good agreement with ECG-derived HR. Conclusion: The investigated DLS sensor was sensitive to movement, overall providing less accurate HR measurements than ECG and pulse oximetry. Application of this cut-off to the second group ( n = 16) showed good agreement between DLS-derived HR and ECG-derived HR (bias –0.73 bpm 95% limits of agreement –15.46 and 14.00 bpm) at the forehead with approximately 80% (i.e., 1,066/1,310) of all data pairs remaining. When applying the international accuracy standard for HR detection, DLS accuracy in the first group ( n = 15) was optimal at the forehead (SNR cut-off 1.66). ECG-DLS paired data points were collected at the forehead, an upper extremity, the thorax, a lower extremity, and the abdomen. Results: HR measurements from 31 infants were analyzed. In the first group, the optimal SNR cut-off value was determined and then applied to the second group to assess agreement.

Patients were randomly divided into 2 groups. We recorded every 10th second of the DLS-derived HR and the DLS signal-to-noise ratio (SNR), and the ECG-derived HR was extracted for analysis. HR was measured with the DLS sensor at 5 different sites for 15 min each. Methods: Stable infants with a gestational age of ≥26 weeks, monitored with ECG, were eligible for inclusion. Objective: The aim was to determine the accuracy of DLS for HR measurement in infants, compared to ECG-derived HR. Recently, the dynamic light scattering (DLS) technique has been miniaturized, allowing noninvasive HR measurements with a single sensor. Background: Heart rate (HR) detection in premature infants using electrocardiography (ECG) is challenging due to a low signal amplitude and the fragility of the premature skin.