Non-invasive techniques have become increasingly vital in modern medicine, providing valuable diagnostic information without invasive procedures. These techniques encompass a diverse range of procedures, including imaging scans, blood tests, urine tests, and genetic testing, enabling the investigation of various conditions without device insertion. In contrast to conventional invasive methods, non-invasive diagnostics have numerous advantages, including reduced complications, shorter recovery times, improved patient comfort, and lower costs. As a result, the exploration of alternative diagnostic approaches has become imperative. This article provides a comprehensive overview of advances, challenges, and opportunities in the realm of non-invasive diagnostic techniques. It delves into a detailed exploration of non-invasive techniques, including photoplethysmography (PPG), electroencephalography (EEG), electromyography (EMG), electrocardiography (ECG), computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), and electrical impedance tomography (EIT) discussing their origin, underlying principles, instrumentation, and applications in various medical fields. Furthermore, the advantages and limitations of various Surface Measurement and Imaging Modalities techniques are thoroughly compared and analysed. The article also addresses these challenges and highlights emerging technologies and methodologies that offer solutions. More importantly, we propose several promising directions for future research and development of non-invasive diagnostic techniques.

非侵入性技术在现代医学中变得越来越重要，无需侵入性操作即可提供有价值的诊断信息。这些技术涵盖多种程序，包括成像扫描、血液测试、尿液测试和基因测试，无需插入设备即可调查各种状况。与传统的侵入性方法相比，非侵入性诊断具有许多优点，包括减少并发症、缩短恢复时间、提高患者舒适度和降低成本。因此，探索替代诊断方法已势在必行。本文全面概述了非侵入性诊断技术领域的进展、挑战和机遇。它深入探讨了非侵入性技术，包括光电体积描记法 (PPG)、脑电图 (EEG)、肌电图 (EMG)、心电图 (ECG)、计算机断层扫描 (CT)、磁共振成像 (MRI)、超声（美国） 、电阻抗断层扫描 (EIT) 讨论其起源、基本原理、仪器和在各个医学领域的应用。此外，还深入比较和分析了各种表面测量和成像技术的优点和局限性。本文还讨论了这些挑战，并重点介绍了提供解决方案的新兴技术和方法。更重要的是，我们为非侵入性诊断技术的未来研究和开发提出了几个有前景的方向。