From Mathematical Ratios to Biophysical Reality: A Personal Learning… (No.1817-1, 10/10/2026)

From Mathematical Ratios to Biophysical Reality: A Personal Learning Experience in Stroke-Warning Research (No.1817-1, 10/10/2026) Gerald C. Hsu EclaireMD Foundation Category: Stroke Warning, Engineering Philosophy ──────── A Special Note Due to my poor eyesight caused by age-related macular degeneration (AMD), my writing may contain occasional typos or minor mistakes. Please forgive these imperfections. ──────── Preface This article documents my thoughts on the relative contribution ratios of eAG and SBP in my TSI-4 stroke-warning model while staying at my Tokyo home. This investigation began with a simple arithmetic question about my Trigger Stroke Index (TSI-4) and developed into a broader examination of theoretical mathematics and physics, practical engineering judgment, medical research, and my industrial experience. I decided to document this process because it illustrates my continuous learning and medical research journey. My objective is not to demonstrate mathematical sophistication. I want to understand underlying biophysical mechanisms and develop practical tools that help me manage my health and survive. I also want to preserve this experience as a time capsule. Perhaps someone studying similar problems decades from now will encounter the same questions and find something useful in my observations. ──────── 1. Background: My Stroke and TSI-4 Model On June 21, 2025, I suffered a hemorrhagic stroke in California. My systolic blood pressure (SBP) reached 175 mmHg around the time of the event. I had lived with type 2 diabetes since 1991. Over the past 3.6 decades, particularly during the first 20 years when I depended on diabetes medications, prolonged metabolic abnormalities had exposed my vascular system, especially my cerebral microvessels, to potential structural deterioration. My interpretation of the stroke involves two principal mechanisms. First, long-term metabolic exposure contributed to the deterioration of my cerebral blood vessels, creating structural vulnerability associated with vascular calcification. Second, an acute elevation in blood pressure to 175 mmHg on June 21, 2025, imposed additional mechanical loading on these vulnerable vessels, contributing to their rupture in the pontine region of my brain. This distinction between long-term structural deterioration and acute mechanical loading is central to my research. I developed several versions of my Trigger Stroke Index, including TSI-3B (using eAG, SBP, and pulse pressure, PP = SBP − DBP) and TSI-4 (using eAG and squared SBP), to examine the combined effects of glucose and blood pressure. My TSI-4 equation, inspired by Einstein’s mass-energy equivalence principle, is: TSI-4 = (eAG / 120) × (SBP / 120)² × 110 Here, eAG represents estimated average glucose, while SBP represents systolic blood pressure. The squared SBP term increases the index’s mathematical sensitivity to blood pressure changes, reflecting my emphasis on mechanical loading as an acute triggering mechanism. TSI-4 is my personal early-warning indicator, not a tool for predicting the exact occurrence of a stroke. ──────── 2. Two Days of Eating in Tokyo I arrived at my Tokyo home on the evening of October 7, 2026, 16 months after my stroke. During my first two days, October 8 and 9, I encountered a familiar Japanese dietary challenge. Many Japanese meals contain substantial carbohydrates and added sugar, particularly white rice, sweetened sauces, and prepared foods. On October 8, I ate a beef rice bowl for breakfast at Sukiya, a fast-food chain restaurant. The meal contained beef, vegetables, an egg, a large bowl of white rice, and sweetened sauce. My postprandial glucose (PPG) increased to more than 250 mg/dL. On October 9, I ate cookies made from rice and sugar and experienced another substantial glucose increase. In both cases, my PPG exceeded 250 mg/dL and required four to five hours to return toward its usual level. My daily eAG increased from near 100 mg/dL to around 120 mg/dL. Fortunately, my SBP remained near 100 mmHg. Nevertheless, the glucose increase caused my TSI-4 to rise from its usual high-60 range into the high 70s. Starting October 10, I decided to prepare my meals at home to control my carbohydrate and sugar intake. Given the vascular damage associated with my long history of diabetes, I cannot afford further unnecessary metabolic stress from dining out in Asia, including Japan. These experiences motivated my mathematical investigation.