Department of Otolaryngology-Head and Neck Surgery, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 1818611, Japan.
Department of Anatomy, Kyorin University School of Medicine, Tokyo, Japan.
Anat Sci Int. 2022 Sep;97(4):347-357. doi: 10.1007/s12565-021-00646-3. Epub 2022 Feb 3.
Tissue-hardening effect and health-hazard issue of formaldehyde (FA) have long been a great disadvantage of this conventional fixative in anatomical research. We recently developed a FA-free embalming method for cadavers which utilizes N-vinyl-2-pyrrolidone (NVP) and enables assessment of motion kinetics by maintaining the softness of embalmed tissue. By assessing the feasibility of NVP-embalmed tissue to mimic vocalization, this study aimed to prove the potential of embalmed cadavers, which have previously been used only for the understanding of anatomical morphology, for the assessment of precise motion physiology in the human body. Ten cadavers embalmed in NVP (n = 6) and FA (n = 4) were incorporated in this study. Excised larynges underwent experimental phonation to mimic vocalization with fast and pliable vibration of vocal folds. High-speed digital imaging was utilized for the assessment of vocal fold vibration. Furthermore, acoustic analysis of the voiced sound, and reproducibility examination were also performed. Regular vocal fold vibrations successfully produced voiced sounds during experimental phonation using NVP-embalmed larynges. The vibratory frequency, vibration amplitude, and stretch rate of the vocal folds were comparable to those of living humans. Six months after the first experiment, the vocal parameters were reproduced, to suggest the long-term preservation potential of our NVP-embalming technique. On the other hand, neither voiced sound nor vocal fold vibration were observed in FA-embalmed larynges. This novel embalming technique could pioneer the next era to utilize embalmed cadavers for the examination of motion physiology in the human body.
甲醛（FA）的组织硬化效应和健康危害问题长期以来一直是这种传统固定剂在解剖学研究中的一大缺点。我们最近开发了一种无 FA 的尸体防腐方法，该方法利用 N-乙烯基-2-吡咯烷酮（NVP），通过保持防腐组织的柔软度来评估运动动力学。通过评估 NVP 防腐组织模拟发声的可行性，本研究旨在证明以前仅用于了解解剖形态的防腐尸体在评估人体精确运动生理学方面的潜力。本研究纳入了 10 具用 NVP（n=6）和 FA（n=4）防腐的尸体。切除的喉进行了实验性发声，以快速且柔韧的声带振动来模拟发声。高速数字成像用于评估声带振动。此外，还进行了语音声音的声学分析和可重复性检查。使用 NVP 防腐的喉，在实验性发声过程中，声带可成功产生语音声音。声带的振动频率、振动幅度和拉伸率与活体人类相当。首次实验 6 个月后，可重复产生发声参数，提示我们的 NVP 防腐技术具有长期保存潜力。另一方面，FA 防腐的喉既没有产生语音声音，也没有观察到声带振动。这种新型防腐技术可以开创一个新时代，利用防腐尸体来检查人体的运动生理学。
