Development of a Novel Web Camera-Based Contact-Free Major Depressive Disorder Screening System Using Autonomic Nervous Responses Induced by a Mental Task and Its Clinical Application.

BACKGROUND: To increase the consultation rate of potential major depressive disorder (MDD) patients, we developed a contact-type fingertip photoplethysmography-based MDD screening system. With the outbreak of SARS-CoV-2, we developed an alternative to contact-type fingertip photoplethysmography: a novel web camera-based contact-free MDD screening system (WCF-MSS) for non-contact measurement of autonomic transient responses induced by a mental task. METHODS: The WCF-MSS measures time-series interbeat intervals (IBI) by monitoring color tone changes in the facial region of interest induced by arterial pulsation using a web camera (1920 × 1080 pixels, 30 frames/s). Artifacts caused by body movements and head shakes are reduced. The WCF-MSS evaluates autonomic nervous activation from time-series IBI by calculating LF (0.04-0.15 Hz) components of heart rate variability (HRV) corresponding to sympathetic and parasympathetic nervous activity and HF (0.15-0.4 Hz) components equivalent to parasympathetic activities. The clinical test procedure comprises a pre-rest period (Pre-R; 140 s), mental task period (MT; 100 s), and post-rest period (Post-R; 120 s). The WCF-MSS uses logistic regression analysis to discriminate MDD patients from healthy volunteers via an optimal combination of four explanatory variables determined by a minimum redundancy maximum relevance algorithm: HF during MT (HF MT ), the percentage change of LF from pre-rest to MT (%ΔLF(Pre-R⇒MT) ), the percentage change of HF from pre-rest to MT (%ΔHF(Pre-R⇒MT) ), and the percentage change of HF from MT to post-rest (%ΔHF(MT⇒Post-R) ). To clinically test the WCF-MSS, 26 MDD patients (16 males and 10 females, 20-58 years) were recruited from BESLI Clinic in Tokyo, and 27 healthy volunteers (15 males and 12 females, 18-60 years) were recruited from Tokyo Metropolitan University and RICOH Company, Ltd. Electrocardiography was used to calculate HRV variables as references. RESULT: The WCF-MSS achieved 73% sensitivity and 85% specificity on 5-fold cross-validation. IBI correlated significantly with IBI from reference electrocardiography (r = 0.97, p < 0.0001). Logit scores and subjective self-rating depression scale scores correlated significantly (r = 0.43, p < 0.05). CONCLUSION: The WCF-MSS seems a promising contact-free MDD screening apparatus. This method enables web camera built-in smartphones to be used as MDD screening systems.

Development and Clinical Application of a Novel Non-contact Early Airflow Limitation Screening System Using an Infrared Time-of-Flight Depth Image Sensor.

Obstructive pulmonary diseases, such as diffuse panbronchiolitis (DPB), asthma, chronic obstructive pulmonary disease (COPD), and asthma COPD overlap syndrome (ACOS) trigger a severe reaction at some situations. Detecting early airflow limitation caused by diseases above is critical to stop the progression. Thus, there is a need for tools to enable self-screening of early airflow limitation at home. Here, we developed a novel non-contact early airflow limitation screening system (EAFL-SS) that does not require calibration to the individual by a spirometer. The system is based on an infrared time-of-flight (ToF) depth image sensor, which is integrated into several smartphones for photography focusing or augmented reality. The EAFL-SS comprised an 850 nm infrared ToF depth image sensor (224 × 171 pixels) and custom-built data processing algorithms to visualize anterior-thorax three-dimensional motions in real-time. Multiple linear regression analysis was used to determine the amount of air compulsorily exhaled after maximal inspiration (referred to as the forced vital capacity, FVC EAFL -SS) from the ToF-derived anterior-thorax forced vital capacity (FVC), height, and body mass index as explanatory variables and spirometer-derived FVC as the objective variable. The non-contact measurement is automatically started when an examinee is sitting 35 cm away from the EAFL-SS. A clinical test was conducted with 32 COPD patients (27/5 M/F, 67-93 years) as typical airflow limitation cases recruited at St. Marianna University Hospital and 21 healthy volunteers (10/11 M/F, 23-79 years). The EAFL-SS was used to monitor the respiration of examinees during forced exhalation while sitting still, and a spirometer was used simultaneously as a reference. The forced expiratory volume in 1 s (FEV1% EAFL -SS) was evaluated as a percentage of the FVC EAFL -SS, where values less than 70% indicated suspected airflow limitation. Leave-one-out cross-validation analysis revealed that this system provided 81% sensitivity and 90% specificity. Further, the FEV1 EAFL -SS values were closely correlated with that measured using a spirometer (r = 0.85, p < 0.0001). Hence, EAFL-SS appears promising for early airflow limitation screening at home.

[Simultaneous analysis of glyphosate and glufosinate in vegetables and fruits by GC-FPD].

A rapid analytical method for residues of the herbicide, glyphosate [N-(phosphonomethyl)glycine], glufosinate [DL-homoalanine-4-yl(methyl)phosphinic acid] and glufosinate metabolite (MPPA: 3-methylphosphinicopropionic acid) in vegetables and fruits was developed by improving the bulletin method of glufosinate. 50 mL of solution extracted with water (corresponding to 2 g of the sample) was loaded on a column packed with 5 mL of anion exchange resin and then the trapped glyphosate, glufosinate and MPPA were eluted with 60 mL of 50% acetic acid. After derivatization with trimethyl orthoacetate, the derivatives were purified and separated on a Florisil cartridge column. The determination of the derivatives was performed with GC-FPD. The detection limits for glyphosate, glufosinate and MPPA were 0.01 microgram/g, 0.01 microgram/g and 0.005 microgram/g, respectively. The recoveries from fortified samples were 83.5-89.8% for glyphosate, 77.9-92.2% for glufosinate and 75.0-87.2% for MPPA.

[Rapid analysis of glufosinate by improving the bulletin method and its application to soybean and corn].

A rapid analytical method for residues of the herbicide glufosinate [DL-homoalanin-4-yl (methyl)phosphinic acid] and its metabolite (MPPA: 3-methylphosphinicopropionic acid) in soybeans and corns was developed by improving the bulletin method. Fifty mL of solution extracted with water (corresponding to 2 g of the sample) was loaded on a column packed with 5 mL of anion exchange resin, and then the trapped glufosinate and MPPA were eluted with 40 mL of 50% acetic acid. After the derivatization of glufosinate and MPPA with trimethyl orthoacetate, the derivatives were purified and separated on a silica gel cartridge column. The determination of the derivatives was performed with a GC-FPD. The detection limits for glufosinate and MPPA were 0.01 microgram/g and 0.005 microgram/g, respectively. The recoveries of glufosinate from soybeans and corns were 86.3-92.0%, and those of MPPA were 86.5-95.2%.