Create app.py

app.py

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+import torch
+import gradio as gr
+import faiss
+import numpy as np
+
+from transformers import AutoTokenizer, AutoModelForSeq2SeqLM
+from sentence_transformers import SentenceTransformer
+
+# Models
+GEN_MODEL_NAME = "google/flan-t5-small"
+EMB_MODEL_NAME = "sentence-transformers/all-MiniLM-L6-v2"
+
+DEVICE = "cuda" if torch.cuda.is_available() else "cpu"
+
+tokenizer = AutoTokenizer.from_pretrained(GEN_MODEL_NAME)
+gen_model = AutoModelForSeq2SeqLM.from_pretrained(GEN_MODEL_NAME).to(DEVICE)
+embedder = SentenceTransformer(EMB_MODEL_NAME, device=DEVICE)
+
+DISCLAIMER = (
+    "Disclaimer: This tool provides general health information only. "
+    "It does not give medical advice, diagnosis, or prescriptions. "
+    "Always speak to a qualified healthcare professional for personal medical concerns or emergencies."
+)
+
+health_facts =  [
+    {
+        "id": 1,
+        "topic": "Hypertension",
+        "text": (
+            "Hypertension is a long-term condition in which the force of blood against the walls of the arteries is consistently too high. "
+            "Over time, uncontrolled high blood pressure can damage blood vessels and organs such as the heart, brain, kidneys, and eyes, increasing the risk of heart disease and stroke. "
+            "Many people with hypertension do not have obvious symptoms, which is why it is sometimes called a 'silent killer', so regular blood pressure checks are important. "
+            "Lifestyle measures such as reducing salt intake, engaging in regular physical activity, managing stress, maintaining a healthy weight, and avoiding tobacco products play a major role in controlling blood pressure."
+        )
+    },
+    {
+        "id": 2,
+        "topic": "Diabetes",
+        "text": (
+            "Type 2 diabetes is a chronic condition in which the body does not use insulin properly or does not produce enough insulin, leading to elevated blood sugar levels over time. "
+            "If blood sugar remains high for many years, it can damage blood vessels and nerves, affecting the eyes, kidneys, heart, and feet. "
+            "People with type 2 diabetes are encouraged to adopt habits such as eating balanced meals with controlled portions, staying physically active, and attending regular medical checkups to monitor blood sugar and related complications. "
+            "Early detection, lifestyle changes, and appropriate medical follow-up can significantly reduce the risk of serious long-term problems."
+        )
+    },
+    {
+        "id": 3,
+        "topic": "Pregnancy nutrition",
+        "text": (
+            "During pregnancy, good nutrition supports the health of both the mother and the developing baby. "
+            "Balanced meals that include vegetables, fruits, whole grains, sources of protein, and healthy fats help supply essential vitamins and minerals. "
+            "Nutrients such as folic acid and iron are especially important in pregnancy because they support the baby’s development and help prevent certain birth defects and anemia. "
+            "Pregnant women are advised to avoid alcohol, smoking, and recreational drugs, and to discuss any supplements or herbal remedies with a qualified healthcare professional during antenatal visits."
+        )
+    },
+    {
+        "id": 4,
+        "topic": "Vaccination",
+        "text": (
+            "Vaccination is a safe and effective way to train the immune system to recognize and fight specific infections without causing the actual disease. "
+            "Many vaccines are given during childhood, but some are also recommended in adulthood, in pregnancy, and for people with certain health conditions. "
+            "Keeping vaccination schedules up to date helps protect not only the individual but also the wider community by reducing the spread of infectious diseases. "
+            "Delaying or skipping recommended vaccines can increase the risk of outbreaks and leave vulnerable groups, such as young children and older adults, unprotected."
+        )
+    },
+    {
+        "id": 5,
+        "topic": "Common cold",
+        "text": (
+            "The common cold is usually a mild infection of the nose and throat caused by viruses, often leading to symptoms such as a runny nose, sore throat, sneezing, and mild cough. "
+            "Most colds improve on their own within a week or two, and complications are uncommon in otherwise healthy people. "
+            "Simple measures such as resting, drinking enough fluids, and using home remedies for comfort can help people feel better while the body fights the infection. "
+            "Because the common cold is viral, antibiotics, which are designed to treat bacterial infections, do not cure it and are generally not needed."
+        )
+    },
+    {
+        "id": 6,
+        "topic": "Asthma",
+        "text": (
+            "Asthma is a long-term condition in which the airways become inflamed and narrow, making it harder for air to move in and out of the lungs. "
+            "People with asthma may experience episodes of wheezing, chest tightness, coughing, and shortness of breath, which can be mild or severe. "
+            "Common triggers include dust, smoke, cold air, respiratory infections, strong smells, and sometimes exercise. "
+            "Understanding personal triggers, avoiding them when possible, and following an asthma action plan from a healthcare professional helps reduce symptoms and improve quality of life."
+        )
+    },
+    {
+        "id": 7,
+        "topic": "Malaria prevention",
+        "text": (
+            "Malaria is a potentially serious disease transmitted by the bite of infected Anopheles mosquitoes, and it is common in many tropical and subtropical regions. "
+            "Early symptoms often include fever, chills, headache, and body pains, which can resemble other illnesses, so testing is important when malaria is suspected. "
+            "Prevention strategies include sleeping under insecticide-treated mosquito nets, using protective clothing, and reducing mosquito breeding sites such as stagnant water around the home. "
+            "Prompt testing and treatment when fever occurs in malaria-endemic areas help prevent severe illness and complications."
+        )
+    },
+    {
+        "id": 8,
+        "topic": "Tuberculosis",
+        "text": (
+            "Tuberculosis (TB) is an infectious disease caused by bacteria that most often affect the lungs. "
+            "It spreads through the air when a person with active TB in the lungs coughs, sneezes, or speaks, and someone nearby breathes in the droplets. "
+            "Common symptoms include a persistent cough lasting more than a few weeks, chest pain, weight loss, night sweats, and fever. "
+            "Early detection, adherence to the full course of treatment prescribed by a healthcare professional, and support from TB programs are important to cure the disease and reduce transmission."
+        )
+    },
+    {
+        "id": 9,
+        "topic": "HIV basics",
+        "text": (
+            "HIV is a virus that weakens the immune system by attacking specific cells that help the body fight infections. "
+            "Without proper treatment and care, ongoing damage to the immune system can eventually lead to AIDS, which is the advanced stage of HIV infection. "
+            "HIV can be transmitted through unprotected sex, sharing needles or sharp instruments that break the skin, and from mother to child during pregnancy, birth, or breastfeeding without preventive measures. "
+            "Regular HIV testing, safer sex practices, and access to appropriate medical care help people living with HIV maintain their health and reduce the risk of transmission to others."
+        )
+    },
+    {
+        "id": 10,
+        "topic": "Mental health",
+        "text": (
+            "Mental health refers to a person’s emotional, psychological, and social well-being, influencing how they think, feel, and behave in daily life. "
+            "Challenges such as prolonged sadness, strong anxiety, loss of interest in usual activities, difficulty concentrating, or major changes in sleep and appetite can signal a mental health concern. "
+            "Life events, ongoing stress, physical illness, and social or economic pressures can all affect mental health. "
+            "Talking to trusted people, seeking professional support, and reducing stigma around mental health conditions are important steps in promoting overall wellbeing."
+        )
+    },
+    {
+        "id": 11,
+        "topic": "Healthy eating",
+        "text": (
+            "Healthy eating means choosing a variety of foods that provide the nutrients the body needs to function well and stay strong. "
+            "Meals that include vegetables, fruits, whole grains, beans or lean animal proteins, and small amounts of healthy fats help support energy, growth, and disease prevention. "
+            "Limiting foods and drinks that are very high in sugar, salt, and unhealthy fats can reduce the risk of conditions such as obesity, hypertension, and type 2 diabetes. "
+            "Regular meal patterns, mindful portion sizes, and drinking enough safe water are also important parts of a healthy eating routine."
+        )
+    },
+    {
+        "id": 12,
+        "topic": "Physical activity",
+        "text": (
+            "Physical activity includes any body movement that uses energy, from walking and household chores to structured exercise and sports. "
+            "Regular movement helps maintain a healthy weight, supports heart and lung function, strengthens muscles and bones, and can improve mood and sleep quality. "
+            "Even small amounts of daily activity are beneficial, especially for people who have been mostly inactive, and it can be built up gradually. "
+            "Choosing activities that are enjoyable and suitable for a person’s age and health status makes it easier to stay active over the long term."
+        )
+    },
+    {
+        "id": 13,
+        "topic": "Childhood fever",
+        "text": (
+            "Fever in children is usually a sign that the body is fighting an infection, which may be caused by viruses, bacteria, or other germs. "
+            "Caregivers should pay attention to the child’s overall behavior, ability to drink fluids, and level of alertness, not just the temperature reading. "
+            "Warning signs that require urgent medical attention include difficulty breathing, convulsions, persistent vomiting, inability to drink, unusual sleepiness, or a fever that lasts several days. "
+            "Keeping the child comfortable, offering fluids, and seeking professional advice when worried helps ensure that serious conditions are not missed."
+        )
+    },
+    {
+        "id": 14,
+        "topic": "Diarrhoea and dehydration",
+        "text": (
+            "Diarrhoea is the passing of loose or watery stools more often than usual and can be caused by infections, food-related issues, or other conditions. "
+            "One of the main dangers of diarrhoea, especially in young children and older adults, is dehydration, which happens when the body loses too much water and salts. "
+            "Signs of dehydration include dry mouth, reduced urination, unusual tiredness, dizziness, and in children, sunken eyes or a sunken soft spot on the head. "
+            "Offering safe fluids, watching for warning signs, and seeking medical care when diarrhoea is severe, persistent, or accompanied by blood or high fever are important steps."
+        )
+    },
+    {
+        "id": 15,
+        "topic": "Menstrual health",
+        "text": (
+            "Menstruation is a normal monthly process in people with a uterus, where the lining of the womb is shed if pregnancy has not occurred. "
+            "Cycle length and flow can vary between individuals, but sudden major changes, very heavy bleeding, or severe pain may require medical evaluation. "
+            "Using clean menstrual products, changing them regularly, and maintaining good personal hygiene help prevent irritation and infections. "
+            "Open, accurate information about menstruation supports dignity, reduces shame, and enables people to manage their periods safely and confidently."
+        )
+    },
+    {
+        "id": 16,
+        "topic": "Oral and dental hygiene",
+        "text": (
+            "Good oral hygiene helps keep the teeth, gums, and mouth healthy, which also supports overall wellbeing. "
+            "Brushing teeth at least twice a day with a suitable toothbrush and fluoride toothpaste helps remove food particles and plaque, reducing the risk of tooth decay and gum disease. "
+            "Cleaning between the teeth, limiting sugary snacks and drinks, and visiting a dental professional for regular checks are also important. "
+            "Ignoring oral health problems can lead to pain, infection, tooth loss, and difficulties with eating and speaking."
+        )
+    },
+    {
+        "id": 17,
+        "topic": "Smoking and health",
+        "text": (
+            "Smoking exposes the body to many harmful chemicals that damage the lungs, heart, and blood vessels, and it greatly increases the risk of several cancers. "
+            "People who smoke are more likely to develop chronic respiratory diseases, heart disease, stroke, and complications from infections. "
+            "Stopping smoking, even after many years, brings health benefits, such as improved breathing, circulation, and reduced risk of heart attack and some cancers over time. "
+            "Support from healthcare professionals, support groups, and smoke-free environments can make it easier for people who smoke to reduce or quit."
+        )
+    },
+    {
+        "id": 18,
+        "topic": "Alcohol and health",
+        "text": (
+            "Alcohol affects the brain, liver, heart, and many other organs, and drinking large amounts or drinking frequently can harm physical and mental health. "
+            "Heavy or risky drinking is linked to liver disease, certain cancers, high blood pressure, injuries, violence, and relationship and work problems. "
+            "Some people are more vulnerable to the effects of alcohol due to age, health conditions, pregnancy, or the medicines they take. "
+            "Reducing alcohol intake, avoiding drinking in unsafe situations, and seeking help when alcohol use feels out of control can lower the risk of harm."
+        )
+    },
+    {
+        "id": 19,
+        "topic": "Obesity and weight management",
+        "text": (
+            "Obesity refers to having excessive body fat that may affect health and is often related to an imbalance between energy taken in from food and energy used by the body. "
+            "It increases the risk of several conditions, including type 2 diabetes, hypertension, heart disease, joint problems, and some cancers. "
+            "Healthy weight management focuses on long-term habits, such as eating balanced meals, being physically active, getting enough sleep, and reducing long periods of sitting. "
+            "Small, realistic changes maintained over time tend to be more sustainable than extreme short-term diets."
+        )
+    },
+    {
+        "id": 20,
+        "topic": "Kidney health",
+        "text": (
+            "The kidneys are organs that filter waste products and excess fluid from the blood and help regulate blood pressure, mineral balance, and red blood cell production. "
+            "Long-term uncontrolled hypertension, diabetes, repeated kidney infections, and some medications or toxins can gradually damage the kidneys. "
+            "Early kidney problems often cause few or no symptoms, so regular checkups are important for people at higher risk. "
+            "Protecting kidney health includes managing chronic conditions with professional guidance, staying hydrated with safe fluids, and avoiding unnecessary use of substances that can harm the kidneys."
+        )
+    },
+]
+
+corpus_texts = [item["text"] for item in health_facts]
+corpus_embeddings = embedder.encode(corpus_texts, convert_to_numpy=True)
+
+dimension = corpus_embeddings.shape[1]
+index = faiss.IndexFlatL2(dimension)
+index.add(corpus_embeddings)
+
+unsafe_keywords = [
+    "dose", "dosage", "mg", "milligram", "tablet", "capsule",
+    "prescribe", "prescription", "how many times", "self medicate",
+    "diagnose", "diagnosis"
+]
+
+def is_potentially_unsafe(question: str) -> bool:
+    q_lower = question.lower()
+    return any(keyword in q_lower for keyword in unsafe_keywords)
+
+def retrieve_facts(query: str, k: int = 3):
+    query_embedding = embedder.encode([query], convert_to_numpy=True)
+    distances, indices = index.search(query_embedding, k)
+    results = []
+    for idx in indices[0]:
+        results.append(health_facts[idx]["text"])
+    return results
+
+def generate_answer_from_context(question: str, contexts, max_tokens: int = 200) -> str:
+    context_str = "\n\n".join(contexts)
+    prompt = f"""
+You are a healthcare information assistant. Use ONLY the information in the context below to answer the user's question in simple language.
+
+Context:
+{context_str}
+
+Rules:
+- Do not make a diagnosis.
+- Do not give medication doses or prescriptions.
+- Encourage the user to talk to a qualified healthcare professional for personal decisions.
+- If the answer is not in the context, say you are not sure and ask them to speak to a professional.
+
+Question: {question}
+
+Answer:
+"""
+    inputs = tokenizer(
+        prompt,
+        return_tensors="pt",
+        truncation=True,
+        max_length=1024
+    ).to(DEVICE)
+
+    with torch.no_grad():
+        outputs = gen_model.generate(
+            **inputs,
+            max_new_tokens=max_tokens,
+            num_beams=4,
+            early_stopping=True
+        )
+
+    answer = tokenizer.decode(outputs[0], skip_special_tokens=True)
+    return answer.strip()
+
+def health_qa_pipeline(question: str) -> str:
+    question = question.strip()
+    if len(question) == 0:
+        return "Please type a question."
+
+    if is_potentially_unsafe(question):
+        safe_msg = (
+            "I cannot provide medication doses, prescriptions, or make diagnoses. "
+            "Please consult a qualified healthcare professional for that. "
+            "I can help with general information only."
+        )
+        return f"{safe_msg}\n\n{DISCLAIMER}"
+
+    contexts = retrieve_facts(question, k=3)
+    answer = generate_answer_from_context(question, contexts)
+    return f"{answer}\n\n{DISCLAIMER}"
+
+def qa_interface(question: str) -> str:
+    return health_qa_pipeline(question)
+
+with gr.Blocks() as demo:
+    gr.Markdown("# 🧠 Health Facts Q&A Bot (Educational Only)")
+    gr.Markdown(
+        "Ask general health questions covered by the internal facts. "
+        "The bot uses retrieval augmented generation and will not give doses or diagnoses."
+    )
+
+    question_box = gr.Textbox(
+        label="Your question",
+        placeholder="e.g. How can I reduce my risk of hypertension?",
+        lines=2
+    )
+    answer_box = gr.Textbox(
+        label="Answer",
+        lines=10
+    )
+    ask_button = gr.Button("Ask")
+
+    ask_button.click(
+        qa_interface,
+        inputs=question_box,
+        outputs=answer_box,
+    )
+
+if __name__ == "__main__":
+    demo.launch()