A soft, flexible microtube sensor and associated method of sensing force are described. A liquid metallic alloy is sealed within a microtube as thin as a strand of human hair to form the physical force sensing mechanism. The sensor is hardly distinguishable with the naked eye, and can be used for the continuous biomonitoring of physiological signals, such as unobtrusive pulse monitoring. Also described is a method of fabricating the microtube sensor and wearable devices incorporating one or more microtube sensors.

Implementations are directed to a pressure-sensing device including a pressure-sensitive sheet, one or more pressure-sensitive input regions disposed along the pressure-sensitive sheet including a first conductive thread including a first length in contact with the pressure-sensitive sheet, and a second conductive thread including a second length in contact with the pressure-sensitive sheet. At least a first portion of the first length of the first conductive thread passes through the pressure-sensitive sheet through a first hole in the pressure-sensitive sheet at a first location and a second portion of the second length of the second conductive thread passes through the pressure-sensitive sheet through a second hole in the pressure-sensitive sheet at a second location.

A gripping force measurement device includes a body portion and a plurality of pressure sensors. The plurality of pressure sensors includes at least one first sensor and two or more second sensors including pressure-sensitive surfaces oriented in the same direction. A pressure-sensitive surface of the first sensor and the pressure-sensitive surfaces of the two or more second sensors are disposed such that, when a subject pressurizes the pressure-sensitive surface of the first sensor and the pressure-sensitive surfaces of the two or more second sensors, the gripping force measurement device is grippable by the subject.

Aspects of the subject technology relate to a sensor for a downhole tool. The downhole tool can include a collar and a sensor. The sensor can be secured to the collar for measuring one or more operational characteristics of the downhole tool during operation of the downhole tool. The sensor can include a substrate. The sensor can also include a plurality of strain gauges disposed on the substrate. The plurality of strain gauges can be configured to measure axial strains and torsional strains on the collar for measuring the one or more operational characteristics of the downhole tool.

A sensor system comprises flexible piezoelectric polyvinylidene fluoride wire/strip and/or a short/extended strain gauge wire/printed strain gauge transducers to measure both static and dynamic pressure, conditioning electronics, installation/adherence tool, calibration tool, electronic devices for measuring pressure outputs, and wireless transmission of sensor signal through a data acquisition system to a smart device. A software application for reading the output of the strain gauges remotely is included. Individual system components include distributed strain sensors, custom printed strain gauges, strain gauge wires, calibration rig, slotted ring clamp, strain measuring devices, and software application for visualization of pressure readings.

A chest tube insertion test device for performing a chest tube insertion training procedure at least partially encloses an insertion tool and includes a microcontroller communicatively coupled to one or more force-sensing resistors. The one or more force-sensing resistors convert an insertion force into a voltage signal sent to the microcontroller. A feedback generator compares the chest tube insertion force to one or more predetermined threshold values and provides feedback to a trainee. The feedback can include an instruction to increase, decrease, or maintain the chest tube insertion force. The feedback is one or more audio cues and/or one or more visual cues (e.g., represented by audio files and/or visual data files stored at the chest tube insertion test device). The chest tube insertion test device detects an insertion force rate of change indicating that the insertion tool has passed through an inner pad of the training model.

A chest tube insertion test device for performing a chest tube insertion training procedure at least partially encloses an insertion tool and includes a microcontroller communicatively coupled to one or more force-sensing resistors. The one or more force-sensing resistors convert an insertion force into a voltage signal sent to the microcontroller. A feedback generator compares the chest tube insertion force to one or more predetermined threshold values and provides feedback to a trainee. The feedback can include an instruction to increase, decrease, or maintain the chest tube insertion force. The feedback is one or more audio cues and/or one or more visual cues (e.g., represented by audio files and/or visual data files stored at the chest tube insertion test device). The chest tube insertion test device detects an insertion force rate of change indicating that the insertion tool has passed through an inner pad of the training model.

Fixing device comprising a fixing member provided with a bearing head, a sensor provided with a detector of the mechanical force to which the fixing member is subjected, the detector being mounted in contact with the fixing member, and a connecting component which is electrically connected to the sensor, which is configured to transmit a measurement of a mechanical force provided by the sensor and which is mounted on the fixing member, the fixing member comprising a body which is mounted on the bearing head and which extends along a longitudinal axis protruding from the bearing head.

Fixing device comprising a fixing member provided with a bearing head, a sensor provided with a detector of the mechanical force to which the fixing member is subjected, the detector being mounted in contact with the fixing member, and a connecting component which is electrically connected to the sensor, which is configured to transmit a measurement of a mechanical force provided by the sensor and which is mounted on the fixing member, the fixing member comprising a body which is mounted on the bearing head and which extends along a longitudinal axis protruding from the bearing head.

An aspect of some embodiments of the present invention relates to a system configured for detecting connection between a pressure pad and a monitor. The system includes a pressure detection circuit and a presence detection circuit. The pressure detection circuit is configured for sensing whether the pressure on the pad is above or below the threshold pressure. The presence detection circuit is configured for determining whether a connection between the monitor and the pad is intact. The presence detection circuit is configured to establish a high voltage condition that occurs when connection is broken along the presence detection circuit and a low voltage condition when the presence detection circuit is intact.