- 學位論文
疼痛評估及其植入式儀器之充電系統設計
Assessing Pain Objectively and Charging System for Implantable Device
摘要
隨著全球人口結構邁向高齡化發展，加上飲食生活習慣及環境的變遷，導致人們患有慢性疾病的機率也大幅提升，根據預估全球有21%的人患有慢性疼痛，其中慢性肌筋膜疼痛症 (Myofascial pain syndrome, MPS)最為常見，美國醫療機構評鑑聯合會(Joint Commission)更將疼痛評估(Pain assessment)列為新的評鑑項目；然而，現今對於疼痛評估的方式仍然使用VAS疼痛量表，往往會受到患者主觀性與心情影響，導致無法精確評估；在疼痛治療上，目前還是以類阿片(opioids)藥物為主流，但療效相當有限且患者將同時承擔相當大的副作用，各專家學者仍積極開發更有效的治療方式；在更精確且有效的評估與治療等議題尚未解決的情況下，導致全球每年仍花費龐大的醫療資源在慢性疼痛管理與治療上。 受惠於材料科學、生物醫學和半導體產業的技術突破與發展下，使得微電子系統與醫療整合上更具發展潛力，其中植入式電刺激器與藥泵可以有效應用於治療慢性疼痛，大幅降低傳統治療副作用，逐漸成為極具價值的疼痛管理系統。然而受限於技術瓶頸，目前仍透過內部獨立電源來維持植入式裝置運作，如何提供更有效率的電源系統，提升植入式裝置的壽命，一直是眾多專家學者致力突破和改善的重要議題，現階段多以無線能量耦合技術將能量傳輸至體內裝置進行充電，雖然可減少更換電池的手術風險，但緊接而來的問題是無線能量傳輸的過程中所產生的熱效應，往往會造成患者不適或是產生不可逆的傷害，如何提供更安全的充電環境一直是相關專家學者持續突破的重要議題。除此之外，對於疼痛評估與量化上，現階段的疼痛管理系統無法立即評估患者狀態並給予最佳的治療，如何開發具有自動評估/分析患者疼痛狀態，同步回授調節治療參數的疼痛管理系統，將會是相關專家學者共同發展的目標。 本研究將針對無線充電過程中組織與電池的溫度議題進行討論與優化；對於疼痛評估上將初步探討多種生理參數與慢性疼痛的關係；除此之外研究過程發現，目前臨床對於MPS的處置上，只針對激痛點(MTrPs)周圍肌肉進行治療，忽略人體本身骨骼結構差異可能對於療效的影響，然而肩胛骨位置、斜方肌與肩部疾病三者間有密切關係，本研究也進一步探討肩胛骨位置對於正常人與斜方肌患有肌筋膜痛症療效的影響。 為了能改善充電過程與無線能量傳輸的溫度問題，針對充電議題上，本研究建立自動化實驗平台，探討充電電流與電池溫度與充電時間三者的關係，進一步提出低溫高效率的充電策略，其實測結果，整個充電過程電池僅升溫0.6℃，組織溫度低於40℃，同時以TSMC 0.35 2P4M 3.3/5V下線製作完成；在無線能量耦合議題上，本研究探討單一及連續動態角度誤差對於充電參數的影響，並開發一套自主校正耦合線圈角度錯位無線能量耦合系統，其實測結果，可有效降低13.66%的組織升溫與縮短4%充電時間。 對於疼痛評估與量化主題上，本研究將初步探討疼痛變化與多種生理參數的關係，同時透過心電圖(ECG)和光體積變化描記圖(PPG)生理參數並搭配疼痛量表(VAS)探討肌筋膜痛症療效的關係，經由統計分析後發現，在主觀疼痛減緩時，會抑制交感神經活性，促使副交感神經興奮，並同步反應於心率變異度(HRV)所對應的參數上。 在肩胛骨位置、斜方肌與肌筋膜痛症療效議題上，本研究透過壓力痛覺閥值(PPT)與表面肌電圖(SEMG)探討其關係，經由統計結果發現，肩胛骨位置較低的MPS患者，治療後主觀疼痛有改善的情況下，其PPT值卻沒有顯著性的改善，推測可能是受到肩胛骨位置較低的影響下，影響PPT值量測的正確性，造成無法精確評估肌肉狀態。 期望透過本研究於無線充電上的相關成果，能在未來提供給相關儀器設計人員參考，建立更安全的充電環境；經由臨床研究的相關結果，能在未來提供相關人員對於疼痛評估上一個更客觀的評估參考指標；另一方面，期望後續對於MPS的相關研究，可參考本研究提出的MPS療效影響因子，進一步開發更有效的療效評估方法。
並列摘要
As the world population structure develops an aging trend, along with changes in diet, lifestyle, and environment, the prevalence of chronic diseases is increasing markedly. According to estimates, 21% of the global population suffers from chronic pain, with myofascial pain syndrome (MPS) being the most common. In the US, the Joint Commission has listed pain assessment as a new evaluation item; however, current methods of pain evaluation use the visual analog scale (VAS), which can be affected by the subjectivity and emotional status of the patient, resulting in inaccurate evaluation of pain. In the treatment of chronic pain, the current mainstream therapy uses opioids, which are of limited efficacy and result in severe side effects; this has led to research in various disciplines for developing more effective therapies for chronic pain relief. Due to unresolved issues regarding precise and effective evaluation and therapy, huge healthcare resources are spent globally on the management and treatment of chronic pain. Benefiting from developments in materials science, biomedical science, and semiconductor technology, the integration of microelectronics and healthcare has shown great promise, with the development of implanted electrical stimulators and drug pumps showing their efficacy in treating chronic pain. Reduction in side effects has been observed compared to traditional therapies, and this is gradually becoming a valuable pain management system. However, due to technical bottlenecks, current implants still use internal, independent electrical sources. Production of an efficient power source and increasing the lifespan of implants have always been important issues for dedicated researchers looking for breakthroughs and improvements in this field of research. Currently, many wireless energy-coupling technologies can transfer energy to the body to charge devices. Although these techniques reduce the likelihood of surgery being required to change batteries, the process of wireless energy transfer indirectly results in problems such as the production of heating effects that cause discomfort and irreversible damage to the patient. Hence, the production of a safe charging environment is an important issue for which researchers are continuously making breakthroughs. In order to improve the charging process and ameliorate the thermal effects caused by wireless energy transfer, an automatic investigation platform was developed in this study to study the charging process. This platform investigated the relationship between charging currents, battery temperature, and charging times, and further suggested a charging strategy of low temperature and high efficiency. The results of the study showed that during the charging process, battery temperature rose by 0.6℃ while tissue temperature remained below 40℃, and this was achieved using a TSMC 0.35 µm mixed-signal 2P4M 3.3/5 V standard CMOS process. On the topic of wireless energy coupling, this study investigated the effects of both singular and continuous dynamic angular misalignment on charging parameters, and developed a wireless energy-coupling system with autonomous correction of coupling coil misalignment. The results showed that this system effectively reduced tissue temperature elevation by 13.66% and charging time by 4%. In the evaluation and quantification of pain, current pain management systems cannot immediately evaluate the patient’s status and provide the best treatment option. Hence, the development of an automated system for the evaluation and analysis of the patient’s pain status and feedback adjustment of therapy parameters is a developmental target of researchers in this field. This pilot study investigated the relationship between changes in pain and multiple physiological parameters regarding the efficacy of myofascial pain syndrome therapy, through the study of the relationships among electrocardiography (ECG), photoplethysmography physiological parameters (PPG), and VAS. Statistical analysis showed that during reduction of subjective pain responses, inhibition of sympathetic nervous activity and excitation of parasympathetic nervous activity occurred, which were reflected in the heart rate variability parameters. However, during the research process, it was found that current clinical management of MPS is focused only on the treatment of muscle surrounding myofascial trigger points, and ignores the potential influences of variation in human bone structure on therapeutic efficacy. Scapula position, trapezius muscle, and shoulder disease are closely related. We therefore investigated the influence of abnormal scapula position on treatment efficacy in patients with trapezius MPS, using pain pressure threshold (PPT) and surface electromyography, to investigate this relationship. After statistical analysis, it was found that MPS patients with a lower scapula position and who showed decrease in VAS did not show increase in PPT values. It was hypothesized that lower scapula position affects the accuracy of PPT measurements, resulting in the inaccurate evaluation of muscle condition.