寒熱脈象診斷標準化研究：冷加壓與熱應力試驗對橈動脈脈波之影響
陳方周
中國醫藥大學中西醫結合研究所
表皮血管擴張或收縮的反應直接受溫度變化的影響以維持人體溫度的恆定，以低溫冷卻皮膚表面可以誘導周圍皮膚血管的收縮，相反地，加熱引起血管的舒張功能。此兩種溫度刺激皆可以激活皮膚的交感神經活動使血管收縮或抑制皮膚血管收縮活動 。研究常以心率變異（heart rate variability‚HRV）的交感神經與副交感神經平衡來評估冷熱刺激引起交感神經活動的改變，HRV 的頻譜分析通常以低頻與高頻率的比值作為衡量心臟交感迷走神經平衡。研究指出冷熱刺激兩者皆會造成皮膚交感神經活性明顯增加，但會引起不同頻率範圍的頻譜能量改變。
中醫脈診以手指指尖按壓手腕部皮膚以診測橈動脈的脈衝，其診測位置稱為「寸口」又名「氣口」，顧名思義，其位置的橈動脈搏動的血與氣變化對中醫有診斷的意義，但大多數人對其價值仍諸多存疑，最重要原因在於其科學性研究尚不足以證明其診斷效力。目前研究分析脈波的方法，基本上分為以分析波形的時域分析法與分析不同波段之頻譜特徵的頻域分析法兩種，研究最多的屬於脈搏波形與低頻(小於10Hz)部分能量的探討。中醫切診是由皮膚直接按脈取得訊號，非只是動脈內搏動壓力，還包括血管至皮膚的所有血管神經活性，研究指出，影響此部分的神經頻率屬較高頻，脈搏波是由自主神經系統所控制，而人體的生理與病理反應也都與神經系統有關。
多年來，冷加壓試驗cold pressor test (CPT)及熱應力(heat stress)試驗已被用來評估交感神經活性與血管的收縮與舒張功能。中醫師每天都會切診相當多的寒病與熱病以及疾病引發的自律神經的改變，為證明中醫脈診的科學性及脈波的頻率與HRV的頻率有相關性，本研究設計兩個實驗，針對與脈搏關係最密切的冷加壓(7oC)與熱應力試驗(45oC)對橈動脈脈波急性影響的分析，藉由比較HRV之交感、副交感平衡與脈波分析的對照。研究方法，cold pressor test是以左手浸入低溫冷水2分鐘，heat stress test是以左手浸入高溫熱水2分鐘，檢測前後的皮膚溫度、血壓、脈波和HRV（心電圖）的變化。預期成果，一則了解冷熱對急性橈動脈脈波的影響，二則脈波哪些頻率的功率頻譜與心率變異性(HRV)LF/HF頻率分布有相關性，此部份可提供中醫對本病切診的科學依據，三則提供中醫師對寒熱溫度急性造成人體切診脈象診測的參考。
關鍵字：冷加壓試驗、熱應力試驗、心率變異性、橈動脈、脈波、頻譜分析
Spectral Analysis of Radial Pulse Wave for Cold Pressor and Heat Stress Test
Fun-jou Chen
Graduate Institute of Integrated Medicine, China Medical University
The dilation or contraction of the epidermis blood vessel’s reaction is directly affected by the surrounding temperature in order to maintain human body temperature steadily. Cooling off the surface skin with the low temperature induces the contractions of the skin blood vessels; on the contrary, the reaction to hot temperature causes the dilation. Both cool and hot temperature stimulations activate the autonomic nerve system to make the skin blood vessels dilation or contraction. A lot of research about cooling/heating effect often uses heart rate variability (HRV) to evaluate the balance of the autonomic nerve system and parasympathetic nerve system.
The pulse diagnosis is done by pressing the area around the wrist to diagnose the radial artery. This area is named as “cun-kou” or “qui-kou”. The changes of blood and qui of radial artery in this area are meaningful to the Chinese medicine. Nevertheless, most people criticize it because its scientific data are insufficient to prove the exactness of diagnosis. Most of the research focused on exploring the pulse waveform and the energy in low frequency (less than 10Hz). The pulse diagnosis extracts the information by pressing the pulse in skin not only the vibration of blood pressure but also the activity of all vessels and nerve activity between the vessel and the skin surface. Pulse is controlled by autonomic nerve system. The reaction of physiology and pathology are related to the autonomic nerve system.
For long, cold pressure test (CPT) and heat stress have been applied to assess the activity of autonomic nerve system. Chinese medicine doctors pulse diagnose many cold diseases and warm diseases everyday and detect the changes caused by unhealthy autonomic nerve system. In order to prove the scientific nature of pulse diagnosis and the relationship between the frequency of waveform and the frequency of HRV, this research have two experiments: cold pressure (7℃) and hot response (45℃) experiments. By comparing the parameters of sympathetic nerve system and parasympathetic nerve system of HRV and the power spectrum density (PSD) of pulse, we may gain three expected findings: to analyze the cold or hot acute temperature changes affecting pulse waveform in radial artery, to identify the relationship between the power spectra of pulse and the LF/HF distributions of HRV, to present the pulse diagnosis phenomenon for the acute response of cold or warm diseases in Chinese Medicine.
關鍵字：Cold pressure, hot response, heart rate variability, radial artery, pulse waveform analysis, frequency spectrum analysis
