# Integrated Multifunctional Laryngoscope for Medical Diagnosis and Treatment
## 1 Introduction  
The larynx plays a vital role in airway protection, respiration, and phonation. Therefore, laryngeal lesions, such as laryngeal cancer, can cause great inconvenience and even fatality to patients [1, 2]. Improvements in disease management, including earlier diagnosis and better use of comprehensive treatment options, can improve the survival rate of laryngeal cancer to some extent [3, 4, 5, 6]. In the diagnosis of laryngeal lesions, the white light laryngoscope [7], which can provide superficial morphology information, can be used during biopsy [8]. However, some early-stage laryngeal cancers are very similar to benign diseases in terms of morphology and may occur in the epithelial layer [9], where they cannot be distinguished by a white light endoscope. False-negative results or voice damage may occur due to medical errors [10, 11]. Therefore, a more reliable and accurate cross-sectional imaging technology is needed.  
Optical coherence tomography (OCT) is an emerging noninvasive cross-sectional imaging technique [12, 13] that has been widely used in a variety of clinical studies [14, 15, 16]. Combining OCT with laryngoscopy can simultaneously acquire superficial morphology information and cross-sectional structure information from the examined tissue. [PERSON] and [PERSON] et al. integrated the fiber-based sample arm of OCT into the lumen of a standard endoscopic device; they obtained images of mucous membranes in the larynx, revealing that the technique could be used for precise guidance in the earlydiagnosis and excision biopsy of tumors [17; 18]. [PERSON] and [PERSON] et al. developed a rigid OCT probe that could be used with a laryngoscope for office-based patient examination without anesthesia [19; 20]. However, this system was a \"double-barreled\" configuration, and the device was large and difficult to operate. A laryngoscope with an integrated OCT beam path was presented by [PERSON] et al. [21; 22]; this single-channel system enabled simultaneous OCT and video laryngoscopy imaging. However, this probe diameter was 10 mm and contained excessive lenses, which would lead to a great loss of the OCT signal. Therefore, a more compact and easy-to-handle dual imaging modality laryngoscope is needed.  
OCT can also be used to evaluate laser surgery for laryngeal lesions [23; 24; 25; 26]. [PERSON] et al. used a spectroscopic element to couple the OCT imaging path with the ablation path; they performed real-time OCT imaging to guide the surgical laser ablation of various tissue types [27]. [PERSON] et al. showed that the integration of OCT and laser ablation enhanced the efficacy of laryngeal organ-preserving surgery [28]. Guided by OCT imaging, the accuracy of the treatment position could be further ensured, and surgical errors could be avoided. However, the diagnostic system is often independent of the treatment system.  
In this work, an integrated multifunctional laryngoscope for medical diagnosis and treatment is presented. The two imaging modes of OCT, i.e., a white light endoscope and a laser ablation treatment mode, are integrated into a common-path system by sharing one probe. The superficial and cross-sectional images can be acquired simultaneously and used for preoperative diagnosis and postoperative evaluation. In addition, under the guidance of dual-mode imaging, the position and depth of the laser ablation treatment system could be accurately controlled. The preliminary results show the potential of this multifunctional integrated endoscopic system for the diagnosis and treatment of laryngeal lesions.