The electronic nose technology in clinical diagnosis: A systematic review

Abstract

Background: Volatile organic compounds (VOC) are end products of human metabolism (normal and disease-associated) that can be mainly excreted in breath, urine, and feces. Therefore, VOC can be very useful as markers of diseases and helpful for clinicians since its sampling is noninvasive, inexpensive, and painless. Electronic noses, or eNoses, provide an easy and inexpensive way to analyze gas samples. Thus, this device may be used for diagnosis, monitoring or phenotyping diseases according to specific breathprints (breath profile). Objective: In this review, we summarize data showing the ability of eNose to be used as a noninvasive tool to improve diagnosis in clinical settings. Methods: A PRISMA-oriented search was performed in PubMed and Cochrane Library. Only studies performed in humans and published since 2000 were included. Results: A total of 48 original articles, 21 reviews, and 7 other documents were eligible and fully analyzed. The quality assessment of the selected studies was conducted according to the Standards for Reporting of Diagnostic Accuracy. Airway obstructive diseases were the most studied and Cyranose 320 was the most used eNose. Conclusions: Several case-control studies were performed to test this technology in diverse fields. More than a half of the selected studies showed good accuracy. However, there are some limitations regarding sampling methodology, analysis, reproducibility, and external validation that need to be standardized. Additionally, it is urgent to test this technology in intend-to-treat populations. Thus, it is possible to think in the contribution of VOC analysis by eNoses in a clinical setting.

Sniffing Out Urinary Tract Infection—Diagnosis Based on Volatile Organic Compounds and Smell Profile

“…It has therefore been argued that this "black box" approach relies too heavily on pattern-recognition algorithms [157]. Moreover, this method cannot yield a targeted VOC biomarker test for the diagnosis of a particular condition or disease [158]. In this case, it is true that the eNose approach cannot identify unique biomarkers for UTI.…”

Sistem Kontrol Berbasis Pemrograman LabVIEW MyRIO untuk Monitoring Kualitas Udara Dalam Ruangan

“…Sistem hidung elektronik (electronic nose (e-nose)) merupakan sistem elektronik yang terdiri dari beberapa jenis komponen sensor yang digunakan sebagai pendeteksi aroma [12,13]. Sensor gas memiliki prinsip kerja berupa perubahan tahanan, Surface Accoustic wave (SAW) yang menyebabkan perubahan nilai tegangan dan arus serta output berupa perubahan frekuensi, Quartz crystal microbalance (QCM ) ketika kadar unsur dan senyawa gas berubah [14,15]. Unsur dan senyawa gas berbahaya yang dimonitor dan dikontrol pada penelitian ini adalah gas Carbonmonoxide (CO) dan Carbondioxide (CO2).…”

eNose breathprints as composite biomarker for real-time phenotyping of complex respiratory diseases

“…What is the performance of eNoses for diagnosing, phenotyping, and monitoring respiratory diseases? Even though the reported accuracies for various diagnoses are relatively good, 3 there are not many studies that have demonstrated replication of data in an independent population (external validation). The latter is required to confirm the quality and clinical value of the observations.…”

“…After appropriate sensor selection, these properties make eNose ''breathprints'' suitable as composite multidimensional biomarkers, providing numerical probabilities for the presence or absence of a particular clinical condition. 3 The large advantage of this technology is its noninvasiveness and ease-to-use, while the results can be made readily available in the doctor's office by eNoses that are linked to online cloud computing 4 (Fig 1).…”

“…It appears that eNose performance is most advanced in asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. 3 This not only refers to diagnostics but also to phenotyping capacities among patients with the same diagnosis. For instance, even though eNoses are capable of diagnosing asthma or COPD accurately as compared with healthy controls, there remains overlap when discriminating these 2 diseases by this technology.…”