本文選題：痛覺　切入點：雙波長激光　出處：《北京協(xié)和醫(yī)學(xué)院》2014年博士論文

【摘要】：痛覺是人們生活中普遍存在的一種不愉快的軀體感覺以及與之相關(guān)聯(lián)的恐懼和負(fù)面情緒。痛覺刺激在腦科學(xué)、神經(jīng)病變的診斷、慢性痛的研究以及止痛藥物和止痛方法研發(fā)等痛覺相關(guān)領(lǐng)域中都有著廣泛的應(yīng)用。它是非常重要的實驗方法,具有極為重要的臨床應(yīng)用價值。有效的痛覺刺激方法是進(jìn)行痛覺研究的必要工具。在各種刺激痛覺刺激方法中,激光誘發(fā)電位技術(shù)(Laser evoked potentials,LEPs)以其非接觸的特異性激活傷害性感受器、同步性好等特點而成為了最為有效的痛覺刺激的實驗方法。目前,該方法已經(jīng)被應(yīng)用于科學(xué)研究和臨床診斷中,并在痛覺相關(guān)領(lǐng)域的研究中起到了不可替代的重要作用。然而,該方法也有一定的不足之處,比如難以控制基線溫度或產(chǎn)生持續(xù)致痛。而這些不足之處又限制了LEPs在痛覺研究中的更進(jìn)一步的應(yīng)用。 本研究基于理論研究和臨床實際對痛覺刺激的客觀需求,提出了一種既可以實現(xiàn)傳統(tǒng)的短暫痛覺刺激,又能實現(xiàn)持續(xù)痛覺刺激、基線溫度控制以及照射面積控制的LEPs技術(shù)、方法和儀器。 針對絕大多數(shù)LEPs只采用脈沖激光刺激工作模式因而難以產(chǎn)生持續(xù)致痛的缺點,本文設(shè)計采用由脈沖980nm半導(dǎo)體激光和持續(xù)輸出的1940nmTm：YAG激光雙系統(tǒng)并行輸出激光的工作方式來進(jìn)行痛覺刺激�；诖嗽O(shè)計,本文研發(fā)了雙波長激光痛覺刺激器的程控電路和上位機軟件,組裝了整個雙波長激光痛覺刺激器系統(tǒng)。為實現(xiàn)本研究的預(yù)設(shè)目標(biāo),本研究重點開發(fā)了以下三個關(guān)鍵技術(shù)：皮膚致痛區(qū)域控制技術(shù)、被照射表面溫度反饋控制技術(shù)和導(dǎo)熱涂層技術(shù)。通過使用由準(zhǔn)直鏡和濾光片組成的簡單的光學(xué)系統(tǒng),實現(xiàn)了對被照射皮膚表面照射區(qū)域的大小和形狀控制,進(jìn)而實現(xiàn)了對皮膚致痛區(qū)域的控制；通過設(shè)計并實現(xiàn)了由測溫模塊、上位機和程控電路中的精密控制電壓源所組成的閉環(huán)反饋控制系統(tǒng)以及對應(yīng)的溫度控制算法,實現(xiàn)了對被照射皮膚表面的溫度控制,進(jìn)而實現(xiàn)了雙波長激光器系統(tǒng)的基線溫度控制和持續(xù)致痛模式；從980nm激光和1940nm激光照射皮膚組織發(fā)生光熱效應(yīng)的機理和上述兩種激光的吸收率出發(fā),研究了導(dǎo)熱涂層技術(shù),將激光熱痛刺激的刺激方式從光熱吸收致痛轉(zhuǎn)變?yōu)闊醾鲗?dǎo)致痛,從而達(dá)到了提升激光刺激效果、降低皮膚損傷風(fēng)險的目的。為驗證上述三個技術(shù)的實際效果,本文設(shè)計并完成了熱痛刺激的離體實驗。通過離體實驗中被照射表面溫度的相關(guān)信息,證明了上述技術(shù)的可行性。 此外,為了了解激光照射在皮膚組織中的溫度分布情況并指導(dǎo)實際科研和臨床致痛研究,本研究建立了經(jīng)雙波長激光照射后,皮膚中的溫度場分布的模型：在通過實驗確定了雙波長激光痛覺刺激系統(tǒng)相關(guān)參數(shù)的基礎(chǔ)上,本文針對1940nm激光在水中吸收率高,折射和反射率低的特點,建立了符合本文所設(shè)計雙波長激光痛覺刺激器1940nm激光實際輸出情況的皮膚雙層有限元(Finite Element Method,FEM)分析模型；本文針對980nm激光在氧合血紅蛋白導(dǎo)熱涂層中吸收率較高的特點,建立了980nm激光照射涂有固定厚度的導(dǎo)熱涂層的皮膚所產(chǎn)生的溫度場分布模型,并通過離體實驗對上述模型進(jìn)行了驗證。 本文所設(shè)計的雙波長激光痛覺刺激器,其優(yōu)勢在于可以在機體上同時或調(diào)制的進(jìn)行短暫致痛和持續(xù)致痛而不會刺激非傷害性感受器。此外,通過對致痛區(qū)域的控制,可以對單位面積上的傷害性感受器進(jìn)行致痛。這在進(jìn)行神經(jīng)纖維在皮膚中的分布密度的檢驗是有用的。基線溫度控制功能,可以防止由于皮膚表面基線溫度不同而對LEPs造成的影響,更有利于誘發(fā)電位信號的檢出。該系統(tǒng)在痛覺研究、臨床診斷和藥物研發(fā)中具有廣泛的應(yīng)用前景和應(yīng)用價值。
[Abstract]:Pain is an unpleasant sensory are prevalent in people's lives as well as associated with the fear and negativity. Pain stimulation in the diagnosis of brain science, neuropathy, chronic pain and analgesic drug research and development and other related fields of pain analgesic method can be widely applied. It is experimental method very important, has very important value in clinical application. The effective method is a necessary tool for pain stimulus pain research. In various stimulation of nociceptive stimulus method, laser evoked potentials (Laser evoked potentials, LEPs) with the specificity of the non contact activation of nociceptors, characteristics of good synchronization etc. become the most effective method for pain stimulation. At present, this method has been applied to the scientific research and clinical diagnosis, and research in pain related field play an irreplaceable However, this method also has some shortcomings, such as difficult to control baseline temperature or produce continuous pain. These deficiencies also limit the further application of LEPs in pain research.
Based on theoretical research and clinical practice, we put forward a LEPs technology, method and instrument which can achieve traditional short-term pain stimulation, and achieve continuous pain stimulation, baseline temperature control and irradiation area control.
For the vast majority of LEPs only by pulse laser stimulation mode so it is difficult to have persistent pain caused by defects, this paper adopts the design of double pulse 980nm 1940nmTm:YAG laser system consists of semiconductor laser and continuous output parallel output laser work manner. Based on the design of nociceptive stimulus, this thesis developed a dual wavelength laser pain stimulator circuit and program the PC software, the whole assembly of the dual wavelength laser pain stimulator system. To realize the target of this research, this study focuses on the development of the following three key technologies: the skin pain caused by regional control technology, feedback control technology and thermal coating technology of irradiation surface temperature. Through the optical system using simple composed of collimator and filter the realization of the control by the size and shape of irradiated skin surface radiation region, so as to realize the pain caused by the skin area The control; through the design and implementation of a temperature measurement module, temperature control algorithm for closed loop control of voltage source precision composed of PC and programmable circuit in the feedback control system and the corresponding to the realization of the temperature control by irradiation of the skin, so as to realize the dual wavelength laser system baseline temperature control and continued to pain model; mechanism of photothermal effect from 980nm laser and 1940nm laser irradiation on skin tissue and the above two kinds of laser absorptivity of studied thermal coating technology, the laser thermal pain stimulation from photothermal absorption induced pain into heat induced pain, so as to improve the laser stimulation effect, reduce the risk of skin the purpose of the injury. In order to verify the actual effect of the three technology, this paper designs and implements the heat pain stimulation in vitro. The in vitro irradiated surface temperature. The closure of the information proves the feasibility of the above technology.
In addition, in order to understand the pain induced by laser irradiation in the skin temperature distribution and guide the practical research and clinical practice, this study established by dual wavelength laser irradiation, the skin temperature distribution in the model is determined by experiments based on the dual wavelength laser pain stimulus system related parameters, based on 1940nm the laser in the water absorption rate is high, refraction and low reflectivity characteristics, established in accordance with the design of dual wavelength laser 1940nm laser output of actual pain stimulator skin double finite element (Finite Element Method, FEM) analysis model; according to the characteristics of higher absorption rate of 980nm laser in hemoglobin oxygen thermal conductive coating in the established temperature distribution model of 980nm laser irradiation with a fixed thickness of the thermal conductive coating produced by the skin and through in vitro experiment on the model test Card.
The design of the dual wavelength laser pain stimulator, its advantages can be carried out in the body at the same time or modulation of pain caused by transient and sustained pain without stimulating nociceptors. In addition, by controlling the pain caused by regional, the unit area of the nociceptors. This is caused by pain useful in test the distribution density of nerve fibers in the skin. The baseline temperature control function, can prevent the effects of different temperature on the surface of the skin baseline caused by LEPs, more conducive to the detection of evoked potential signals. The system in pain research, has wide application prospect and application value in clinical diagnosis and drug development.

【學(xué)位授予單位】：北京協(xié)和醫(yī)學(xué)院
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：R312

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

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本文編號：1662665