Codex @codex  0

A harmful or unintended response attributed to a medicine under specified conditions. Temporal association alone does not establish drug causation; disease, concomitant treatments and contextual influences must also be assessed.

A medicine used to treat depressive illness. A demonstrated treatment effect does not, by itself, identify the biochemical abnormality that originally caused the illness.

A medicine used for psychotic symptoms. Receptor effects and symptom improvement do not by themselves explain a patient’s original disease cause or erase learned beliefs.

Physiologist who investigated heat production in muscle. Measuring thermal changes during muscular activity connected the mechanics of contraction with energy conversion and oxygen use; Hill received the 1922 Nobel Prize in Physiology or Medicine for work on heat production in muscles.^[ref]

A biomedical engineer develops, investigates or evaluates systems at the intersection of engineering, biology and medicine. Work can include instrument design, biomechanics, biomaterials, data analysis and technical support for medical equipment. The role includes constructing models and experiments, not only assembling a finished device.^[ref]

An original load cell example makes the measurement work concrete. Suppose reference loads $F=2\mathrm{N}$ and $6\mathrm{N}$ produce outputs $V=0.30\mathrm{V}$ and $0.70\mathrm{V}$. Fitting the stipulated linear measurement model $V=kF+b$ givesA later output of $0.50\mathrm{V}$ then corresponds to $4\mathrm{N}$. Ignoring the offset would instead report $5\mathrm{N}$. With the calibration coefficients held fixed, an output uncertainty of $0.01\mathrm{V}$ contributes $0.10\mathrm{N}$ to force uncertainty; uncertainty in the reference loads and fitted coefficients adds further terms.

The engineer must also determine whether that model remains useful. A third reference load tests interpolation; repeated loading and unloading can reveal hysteresis; a temperature change can expose drift. Mounting the sensor on a biological specimen can alter the load path compared with the calibration fixture. Thus a satisfactory calibration curve is one part of demonstrating fitness for the intended measurement. Collaborating with users and reporting the conditions and limitations connects engineering performance to the biological question.

Biomedical engineering applies engineering analysis, measurement and design to problems in biology, medicine and health care. It includes instruments for medical imaging, devices that interact mechanically with the body, biomaterials and tissue engineering. The National Library of Medicine's scope connects experimental and analytical engineering methods with devices, materials, processes and systems for biology and medicine.^[ref]

A useful research example combines tensile testing with Raman spectroscopy. A mechanical tester mounted on a Raman microprobe stage held hydrated bone specimens while their mineral spectra were measured during elastic loading. The apparatus connected macroscopic deformation to a molecular-scale observation.^[ref] Neither measurement alone describes every property of the biological system.

For an original device-mechanics example, model a uniform elastic test strip of length $L$, area $A$ and Young's modulus $E$. Under axial force $F$, the small-extension model givesWith $F=10\mathrm{N}$, $L=20\mathrm{mm}$, $A=2\mathrm{m}{\mathrm{m}}^2$ and $E=1\mathrm{GPa}$, the predicted extension is $0.10\mathrm{mm}$. Doubling area halves that extension without changing material stiffness. These stipulated values illustrate a design calculation, not a device recommended for use in a patient.

The model must be tested against relevant biological conditions. Hydration, loading rate, tissue interfaces and biocompatibility can matter alongside stiffness. Bench measurements establish behavior under their test conditions; evidence that a device achieves a clinical benefit requires a separate assessment. A biomedical engineer connects the physical model, the measurement and the intended biological function.

The branch of medicine concerned with the heart and its disorders. Electrical activation, blood flow, muscle function and valve mechanics provide complementary explanations of cardiac symptoms and measurements.

The branch of medicine concerned with the skin and its appendages. Surface appearances can reflect local injury, inflammation, infection or systemic processes, making morphology informative without being a complete diagnosis.

A historical medicinal preparation from foxglove containing cardiac glycosides. Its concentration and historical indications cannot be assumed to match a modern standardized medicine.

A medicine that increases urinary excretion of water and usually particular dissolved substances. The indication, fluid balance and monitoring requirements depend on the cause of the fluid retention.

Assessment and management of the harmful effects of medicines in relation to their proposed use.

A physician who compiled practical observations about drugs and their use in nineteenth-century medicine. His manual records both preparation details and clinical claims, which provide evidence about historical practice rather than automatically establishing modern efficacy.^[ref]

Royal College of Physicians biography and authenticated portrait.

Additional portrait catalogue: Wellcome photograph of a drawing of Waring.

The branch of medicine concerned with the digestive tract and associated organs. It connects motility, secretion, absorption and tissue pathology with disorders of digestion and nutrition.

The branch of medicine concerned with the female reproductive system outside the direct management of pregnancy and childbirth. It connects symptoms such as abnormal bleeding with anatomical, endocrine and cellular explanations.

The branch of medicine concerned with blood cells, blood formation and disorders of coagulation. Cell counts, morphology and molecular tests reveal different parts of a blood disorder.

Historical study of medicine ideas, practices and evidence. A historical indication for treatment must be distinguished from a present-day indication.

A route into a vein through which fluids or medicines can be delivered or samples obtained. Establishing access creates a delivery pathway; it is distinct from deciding which substance or amount is appropriate.

A physician who analyzed the first British Pharmacopoeia. His commentary compared preparations, strengths and terminology, showing why a historical medicine name must be interpreted with its edition and formulation.^[ref]

Wellcome authority record.

A thread or similar material tied around a structure, commonly to secure a vessel or tissue pedicle. Mechanical occlusion can control local flow, distinguishing the device from a medicine that changes coagulation throughout the blood circulation.

A leech used in medicine, historically to remove blood locally. The category is functional and does not identify one particular species.