One embodiment relates to a pressure sensor apparatus, including a housing with a flexible member and an aperture configured to receive a fluid. The pressure sensor apparatus further includes a first member disposed on the flexible member, a second member removably coupled to the first member configured to move in response to a pressure of the fluid and a sensor configured to detect the movement of the second member. The pressure sensor apparatus generates a pressure signal for the fluid based on the displacement of the second member.

Disclosed herein is a device which is intended to deliver and maintain reduced pressure to body surfaces for application of reduced pressure wound therapy (RPWT) also known as negative pressure wound therapy (NPWT). During application of this type of therapy, a substantially airtight seal is formed around a section of tissue to be treated. This seal is formed by a dressing which provides fluid communication from a section of tissue to a reduced pressure source. Disclosed herein is a dressing system which is configured to enhance usability and functionality of this dressing. First, the system may be configured to allow full rotation of the fluid communication conduit to the reduced pressure source along the axis substantially normal to the dressing. Second, the system may be configured to include a one-way valve to prevent backflow of any drainage fluids. Third, the system may be configured with transparent windows covered by opaque flaps to allow inspection through the dressing. Fourth, the system may be configured to include an indicator which visually makes clear whether reduced pressure is being applied or not. Fifth, the system is configured to minimize the profile of the dressing system.

Pressure indicator comprising a base, a deformable membrane fixed to the base in a fluid-tight manner according to a closed contour, and a body fixed to the base, delimiting a hollow volume covering the deformable membrane on the side opposite the base, while encompassing at least the closed contour, at least one inlet for a fluid the pressure of which is to be measured in a pressure range, wherein the deformable membrane is such that the expansion thereof for said pressure range is sufficient to be visible to the naked eye and to allow a direct display indicative of the pressure, in that the base is drilled with at least one first hole a first end of which emerges between the deformable membrane and the base in the closed contour, in that the body is drilled with at least one second hole a first end of which emerges into said hollow volume, in that the other end of the first hole is linked to the inlet respectively to the open air, in that the other end of the second hole is linked to the open air, respectively to the inlet, so that a pressure, respectively a pressure reduction, of fluid at the inlet causes an expansion of the deformable membrane in the hollow volume delimited by the body. Application of such an indicator to the monitoring of the inflation of a medical apparatus pad.

Provided is a pressure sensor that includes a detection film that is arranged on a silicon substrate, detects a pressure applied to a surface thereof, and generates a protrusion deformation in response to the pressure. The pressure sensor also includes an optical transmitter and an optical detector that are arranged on the silicon substrate on opposite sides of the detection film and are located at a plane parallel to a plane comprising the detection film. The pressure sensor also includes a pressure calculation module that is connected to the optical detector and is used for acquiring light intensity data and calculating a pressure value according to the light intensity data. Also provided is a method of manufacturing the pressure sensor.

A method for forming a pressure sensor is provided wherein an optical fibre is provided, the optical fibre comprising a core, a cladding surrounding the core, and a birefringence structure for inducing birefringence in the core. The birefringence structure comprises first and second holes enclosed within the cladding and extending parallel to the core. A portion of the optical fibre comprising the core and the birefringence structure is encased within a chamber, wherein the chamber is defined by a housing comprising a pressure transfer element for equalising pressure between the inside and the outside of the housing. An optical sensor is provided along the core of the optical fibre. Providing the optical sensor comprises optically inducing stress in the core so that the optical sensor exhibits intrinsic birefringence. The chamber is filled with a substantially non-compressible fluid. Consequently, the birefringence structure is shaped so as to convert an external pressure provided by the non-compressible fluid within the chamber to an anisotropic stress in the optical sensor.

Embodiments provide a fluid detection device including a casing connectable to a tube filled with water and allows the water to flow to a hollow inner part; a partition wall deformable so that the hollow inner part is divided into a fluid chamber filled with the water and an air chamber opened to the atmosphere; a slide tip disposed inside the fluid chamber; and a tip sensor disposed outside the casing. According to at least one embodiment, a slide holding part which holds the slide tip slidably forward and backward is formed inside the fluid chamber, an opening part is formed in the air chamber, a magnet is disposed in the casing, the slide tip includes a magnet provided at a position facing the magnet and repelling the magnet.

A sensor and methods of making a sensor are disclosed. The sensor may include a substrate including an opening, an optical source disposed in the substrate and configured to generate an optical source signal, an optical detector disposed in the substrate so that the opening is disposed between the optical source and the optical detector, a plurality of optical cavity structures disposed in the opening wherein each of the plurality of optical cavity structures contains an enclosed cavity so that the respective enclosed cavities are not in gas communication with each other, wherein the plurality of optical cavity structures are arranged in an optical path between the optical source and the optical detector, and a processing circuit coupled to the optical detector and configured to process an optical signal received by the optical detector.

A sensor and methods of making a sensor are disclosed. The sensor may include a substrate, an optical source, an optical detector, a plurality of optical cavities in the substrate or in a layer structure over the substrate, where the plurality of optical cavities may be arranged in an optical path between the optical source and the optical detector, and a processing circuit coupled to the optical detector and configured to receive a signal representing an optical signal received by the optical detector.

The photoelastic polyurethane resin has a Young's modulus at 25 C. of 2 to 5 MPa, a photoelastic constant at 25 C. of 100010.sup.12 Pa.sup.1 to 10000010.sup.12 Pa.sup.1, and a glass transition temperature of 60 C. to 21 C.

An optical fiber sensor can be used to measure pressure with high sensitivity and fine resolution. As a cavity at the end of the sensor expands or contracts, the spectrum of a beam reflected from the end of fiber shifts, producing a change linked to pressure exerted on the sensor. Novel aspects of the present inventive sensor include the direct bonding of a silica thin film diaphragm to the optical fiber with localized or confined heating and a uniform thickness of the diaphragm. The resulting sensor has a diameter that matches the diameter of the optical fiber. Because the sensor is all silica, it does not suffer from temperature-induced error. In addition, the sensor can be very sensitive because the diaphragm can be very thin; it can also make highly repeatable measurements due to its very uniform thickness.