音樂節奏影響心率變異性：演算法，模型，與應用

Abstract

心跳間距由自主神經系統控制。心率變異性狹義可以指心跳間距的標準差，廣義則可以指由心跳間距導出的時域與頻域各參數。心率變異性會受到情緒的影響，而音樂又可誘發各種情緒，因此長期以來，有不少論文提出單一音樂要素如何影響心率變異性，但至今仍少見多音樂要素如何影響心率變異性。

音樂三要素為節奏、音調與音色，其中以節奏最重要。而節奏三要素為樂曲速度、節奏複雜度與能量。本論文共有以下五項內容：第一，為前驅實驗。在單一樣本的植物人音樂實驗中，若以強烈情緒的音樂刺激，可以提高心率變異性。第二，研究節奏三要素如何影響心率變異性。透過量化的數據加以數學分析，提出演算法分析其對應關係，建立音樂生理模型。第三，分析休息狀態的心率變異性。第四，以數據反對長期心率變化/短期心率變化可以成為自主神經低頻能量/自主神經高頻能量的代替品。第五，發現實驗者對於單調節奏的樂曲速度的喜好呈雙峰現象。

若搭配自動作曲系統，則可以根據本研究提出的演算法分析心率變異性等生理資料，即時合成音樂調整身心狀態，達到振奮、放鬆、喜悅、悲傷等情緒，有別於傳統以某些特定樂曲進行的音樂治療。

Heartbeat intervals are controlled by the autonomic nervous system (ANS). Heart rate variability (HRV) means the standard deviation of heartbeat intervals; it also refers to all the time and frequency domain parameters derived from heartbeat intervals. HRV is affected by emotions, and emotions can be induced by a variety of music. For a long time, many papers presented how single elements of music affect HRV, but the works of multiple elements were rare.

This paper includes five major parts: Initially, the pilot study was performed; in a single vegetative sample of musical experiments, the strong emotion of music increased HRV. Secondly, how the three elements of rhythm affect HRV has been studied. We quantified the data and analyzed the correspondence between musical rhythm and HRV by the proposed algorithm, and established the musical physiological model. Thirdly, the resting HRV was analyzed. Fourthly, we proposed that SDNN/RMSSD (standard deviation of normal to normal RR intervals / root mean square of successive NN interval differences) is not a proper surrogate for LF/HF. Finally, the experiments found that monotonous rhythm derived a twin-peak phenomenon.

When the algorithm proposed in this study is embedded into an automatic composing system, we can analyze music and HRV, real-time adjust the physical and mental state by the synthesis of music.