Apparatus and method for simulating lung sounds in a patient simulator

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS OF THE INVENTION One embodiment of the current invention comprises a computer-based physiologic model covering the following subsystems: cardiovascular; uptake and distribution; neuromuscular; pharmacokinetics/pharmacodynamics and physiologic control models.
Also included is a unique way of linking the different subsystems to realistically simulate the interactions between the subsystems and the control system in response to the actions of a trainee, student, or other user (including input from both a computer peripheral such as a mouse/keyboard, wired remote keypad, wireless remote control unit, barcode reader and from sensors physically embedded in the full scale lung/patient simulator).
A significant part of a patient simulator useful for training anesthesiologists and other physicians comprises a subsystem to perform gas exchange.
The lung model on the instant integrated patient simulator consumes and produces gases, just like a human lung.
Uptake and excretion of O.
sub.
2, CO.
sub.
2, N.
sub.
2, N.
sub.
2 O and volatile anesthetic gases are physically created and simulated, based on the measured concentrations in the bellows of the simulated lung and in a software model representing uptake, distribution, storage, consumption, and/or production in the body.
Lung perfusion is also accounted for in this model by modeling of the cardiovascular subsystem of the patient being simulated by the physiological model.
Alveolar ventilation is dependent on the lung mechanics and, in the case of spontaneous breathing, is driven by the physiologic control and pharmacokinetics/pharmacodynamics models.
See Guyton, A.
C.
, Textbook of Medical Physiology (8th ed.
), W.
B.
Saunders Co.
, Philadelphia, 1991.
The lung model portion of the patient simulator is capable of simulating spontaneous breathing with computer control of tidal volume (VT) and respiratory rate (RR).
Spontaneous movement of the bellows is driven by an analog muscle pressure signal to simulate inspiration, active expiration, coughing, and different spontaneous breathing patterns (I/E ?inhalation/exhalation! ratio, respiratory rate, respiratory patterns associated with light anesthesia