Anesthesia Delivery Module
The Science
The Science Behind MADM™
MADM™ is the world’s first inline direct injection anesthetic vaporiser. It’s versatility and portability make it ideal not only in the controlled environments of operating rooms, intensive care units and medical clinics, but also for delivering gas anesthesia in more challenging environments i.e., field hospitals and forward-deployed surgical operations.
MADM™ integrates the functions of gas anesthesia delivery and respiratory gas monitoring, automatically adapting its operation to the type of ventilator it is connected to.
Closed-Circuit Configuration
When MADM™ is used in a closed/circle-circuit configuration, any vapor anesthetic which is not consumed by the patient is exhaled back into the circuit and retained (to be used as part of the next breath). The Anesthetic and CO2 Monitoring Sensor is inserted on the inspiratory line/tube near the patient’s mouth allowing it to measure and display inspiratory and expiratory vapour anesthetic and carbon dioxide concentrations on the LCD display screen.
MADM™ measures the flow and anesthetic concentration of the gas entering the system on the inspiratory limb of the ventilator circuit via its internal flow sensor and inlet gas. MADM™ then adjusts its internal liquid anesthetic delivery pump and controls the anesthetic vaporization rate and consequently the concentration of anesthetic in the gas exiting the system and delivered for patient inhalation.
The process automatically reduces the amount of liquid anesthetic being vapourized, compensating for the unused anesthetic returning from the patient.
MADM™ In-line Vaporizer
Schematic diagram of MADM™ in-line vaporizer. This vaporizer is interposed on the inspiratory limb of any circuit. It senses the input flow (1) and volatile anaesthetic (VA) concentration (2). The data processor and device controller (3) compares the input mass of VA with the target output designated by the dial [8]. It instructs the pump (4) to transfer VA from the anaesthetic reservoir (5) to the vaporization chamber (6) and the vapor pump (7) to top up the inspired gas with the appropriate mass of VA to meet the target concentration. Sensor (1b) is attached to the endotracheal tube and monitors inspired and end-tidal anaesthetic concentrations.
