A portable pump is provided for negative pressure wound therapy for drawing a vacuum from a wound site via a tube. The pump includes an inlet configured to attach the tube from the wound site; a canister in fluid communication with the inlet for collecting fluids drained from the wound site; and a manually-actuated pump mechanism for creating the vacuum. The pump mechanism includes a vacuum chamber in fluid communication with the canister; a piston disposed in the vacuum chamber; and a pump handle coupled to the piston to move the piston in the vacuum chamber between first and second positions to create the vacuum. The pump handle moving between a retracted position and an extended position. The piston is in the first position when said pump handle is in the retracted position and is in the second position when said pump handle is in the extended position.

A surgical suction device that uses positive pressure gas is shown and described. The surgical suction device includes an air amplifier. The air amplifier includes a structure defining a generally cylindrical cavity having a first opening at a first end and a second opening at a second end. The cylindrical cavity is defined by an inner wall of the cavity. The air amplifier includes an annular opening in the inner wall near the first end. The annular opening defines a jet opening adapted to allow a pressurized gas to flow out of the annular opening such that a low pressure region is produced at the first end and an amplified flow is produced at the second end. The annular opening is further configured such that the pressurized gas enters the cavity at an angle with respect to the inner wall of the cavity that is towards the second end.

Various exemplary methods, systems, and devices for joint to pump elevation level user interfaces, autocalibration for joint elevation, and joint pressure estimation are provided. In general, an arthroscopic pump can be configured to estimate fluid pressure at a surgical site, e.g., at a joint, to provide an accurate indication of fluid pressure to users. In an exemplary embodiment, the fluid pressure estimation is based on a fluid pressure measurement at the pump that is adjusted at the pump, e.g., by a processor at the pump that executes instructions stored in a memory at the pump, using one or more control algorithms that adjust for one or more factors, such as pressure loss in tubing and sheath through which fluid flows between the pump and the surgical site and elevation difference between the pump and the surgical site.

Described herein are devices, systems, and methods for generating a variable liquid vacuum with an accompanying stable gas flow rate. In particular, when a suction device suctions a liquid and gas mixture it is advantageous to provide a variable vacuum or vacuum to apply to the liquid component while the flow rate of the gas stays constant or essentially constant.

A wound therapy system includes a negative pressure circuit configured to apply negative pressure to a wound, a pump fluidly coupled to the negative pressure circuit and operable to control the negative pressure within the negative pressure circuit, a pressure sensor configured to measure the negative pressure within the negative pressure circuit or at the wound and a controller communicably coupled to the pump and the pressure sensor. The controller is configured to execute a pressure testing procedure including applying a pressure stimulus to the negative pressure circuit, observe a dynamic pressure response of the negative pressure circuit to the pressure stimulus using pressure measurements recorded by the pressure sensor, and estimate a wound volume of the wound based on the dynamic pressure response.

A chest drainage system including a collection device configured to receive fluid from the pleural cavity of a patient. A sensor is included to detect a pressure differential in the fluid. A display is configured to display a trend in occurrences of changes in pressure of the fluid over time in predetermined time increments based on a number of detections of pressure differentials that exceed a predetermined pressure differential during each of the predetermined time increments. The trend is correlative to the percentage of time that the patient is deemed to have an air leak in the pleural cavity in the predetermined time increments. The trend is derived from a ratio of the quantity of respiratory cycles of the patient for which the predetermined pressure differential is detected (QRC.sub.leak) in the predetermined time increments to the total quantity of respiratory cycles of the patient in respective predetermined time increments (QRC.sub.total).

A wound treatment appliance is provided for treating all or a portion of a wound. In some embodiments, the appliance comprises a cover or a flexible overlay that covers all or a portion of the wound for purposes of applying a reduced pressure to the covered portion of the wound. In other embodiments, the wound treatment appliance also includes a vacuum system to supply reduced pressure to the site of the wound in the volume under the cover or in the area under the flexible overlay. Methods are provided for using various embodiments of the invention.

A negative pressure wound therapy apparatus can include a wound dressing, a fluid collection container, a vacuum pump comprising a pump motor, and tubing. Additionally, the apparatus can include a pressure sensor that measures a pressure in the tubing. One or more tubes can channel a fluid between the wound dressing, the fluid collection canister, and the pump. In addition, first and second control circuits can be provided for controlling the pump motor without using a processor. The first control circuit can generate a difference signal between a desired pressure input and a pressure sensor input, and can further generate a motor control signal responsive to the difference signal. Moreover, a second control circuit can provide an override signal based at least in part on the difference signal and at least one reference signal. The override signal beneficially overrides the motor control signal to prevent the pump motor from stalling.

Embodiments of a negative pressure wound therapy systems and methods for operating the systems are disclosed. In some embodiments, a system includes a pump assembly, canister, and a wound dressing configured to be positioned over a wound. The pump assembly, canister, and the wound dressing can be fluidically connected to facilitate delivery of negative pressure to a wound. The pump assembly can present graphical user interface screens for controlling and monitoring delivery of negative pressure. The system can be configured to efficiently deliver negative pressure and to detect and indicate presence of certain conditions, such as low pressure, high pressure, leak, canister full, and the like. Monitoring and detection of operating condition can be performed by measuring one or more operational parameters, such as pressure, flow rate, and the like.

Some embodiments are directed to a system 10 for the application of topical negative pressure therapy to a site 18 on the body of a mammal. Some embodiments of the system 10 comprise a piston 22 and cylinder 24 device 12 having a self-contained power source for the generation of a reduced pressure and for aspirating the site 18. Some embodiments of the system 10 comprise a dressing 14 sealably surrounding the site 18 that can be operably connected to the device 12 by a conduit means 16 to apply the reduced pressure to the site 18.