Abstract: A more efficient exercise system can be facilitated by interactive components. The interactive components can communicate with mobile devices, users, server devices, weight lifting machines, etc. The interactive components can also generate exercise data and provide prompts to a user to facilitate a more efficient workout. Additionally, third-parties can receive user workout data and manipulate exercise equipment remotely to assist a user in attaining his or her goals.

Abstract: A sound processing system measures one or more periauricular muscle signals from one or more periauricular muscles of a user. Additionally, the sound processing system computes, based on the periauricular muscle signals, an estimate of an angle corresponding to a direction of a current auditory attention locus of the user with respect to a reference point or plane. The sound processing system controls, based on the estimate of the angle, an operating characteristic of the sound processing system.

Abstract: A measurement system for use in an exercise machine, which exercise machine comprises a lifting mechanism and an engaging member for selectively engaging a number of stacked weights to the lifting mechanism, the measurement system comprising a pair of cooperating members including a range meter and a reflector member, wherein one of the cooperating members is connected to the lifting mechanism and the other of the cooperating members is connected to the engaging member, wherein the range meter is directed to measure a distance to the reflector member to determine a distance which correlates to the weight of the selectively engaged weights.

Abstract: Devices and methods for stimulation and recording of muscle responses for determining degree of neuromuscular blockade, particularly relevant to elicitation of such responses in those under the influence of anesthesia. A system for estimating the degree of neuromuscular blockade includes at least one stimulating electrode, at least one recording electrode, a pulse generator for providing stimulation to a nerve through the stimulating electrode, and a computing device configured to: apply stimuli to the nerve according to a stimulation protocol, wherein the stimulation protocol provides a plurality of stimulation sequences that vary in frequency of pulses in the stimulation sequence, frequency of the stimulation sequences, number of pulses in the stimulation sequence, or all of the above; measure, by the recording electrode, electrical responses of a muscle; and estimate the degree of neuromuscular blockade based on changes in the electrical responses of the muscle during a stimulation sequence.

Abstract: A wearable device has a core contraction sensor. Signals from the core contraction sensor are transmitted to a processor which analyzes the core contraction signals and determines if the user's core is contracted or relaxed. The processor can cause a computing device to output a sequence of tones in response to a core contraction signal. The sequence of tones can correspond to a song which can be played by performing a plurality of core contractions with durations that correspond to a duration of the notes in the song. Alternatively, the core muscles can be contracted to correspond to music heard by the user. The processor can output a score based upon the matching of the core contractions with the musical notes.

Abstract: In a method and system for use with a ventilator for mechanical ventilation of a patient, a sensor arrangement registers at least one signal related to muscular activity of at least one muscle in the laryngopharyngeal region of the patient. This signal is provide to a computer, which controls the operation of the ventilator based thereon, and/or causes display of information related to the signal in order monitor the patient and/or operation of the ventilator.

Abstract: Systems and methods are disclosed for operating a joint of a prosthesis during a phase of stance. In an embodiment, a method for such operation comprises determining a joint angle of the joint, determining a walking speed of the prosthesis, retrieving a torque value from a lookup table stored in a memory, on the basis of the joint angle and the walking speed, and initiating a signal to apply a torque to the joint of the prosthesis in an amount based on the torque value.

Abstract: A system and a method for detecting a muscle activity are provided. The system includes a vibration sensor. The vibration sensor detects a vibration signal at a sensing point located at an opposite side of an operating muscle system for analyzing a body movement.

Abstract: Methods of stimulating a nerve may include inserting a lead structure into one or more blood vessels. The lead structure may include an insulating member, first electrodes and second electrodes supported on the insulating member, and at least one metal lead. The first electrodes and second electrodes may be positioned in one or more blood vessels. The methods of stimulating a nerve may further include the lead structures being applied to stimulate nerves such as the phrenic, vagus, trigeminal, obturator or other nerves.

Abstract: Systems and methods are described for detecting and characterizing seizures or seizure-related events. The methods herein may include determining magnitude and/or scaled magnitude data for each of at least one high and low frequency group of signals. Based on the determined magnitudes and/or scaled magnitude data, seizures or seizure-related events may be characterized.

Abstract: Embodiments of the present disclosure are configured to assess the severity of a blockage in a vessel and, in particular, a stenosis in a blood vessel. In some particular embodiments, the devices, systems, and methods of the present disclosure are configured to provide FFR measurements in a small, compact device that integrates with existing proximal and distal pressure measurement systems and does not require a separate power source.

Abstract: Provided is a system for measuring biological signals of a user, which includes a sensor module configured to acquire ballistocardiogram (BCG) signals of a user via a present channel, where the present channel is at least one channel of the sensor module, a decomposition module configured to decompose the BCG signals to decomposed signals, a reconstruction module configured to reconstruct at least a portion of the decomposed signals to reconstructed signals, a processing module configured to process the reconstructed signals to at least one of a heart rate, respiration rate, phases of respiration, and blood pressure, and a display module configured to display at least one output corresponding to the at least one of the heart rate, the respiration rate, phases of respiration, and the blood pressure on a display device.

Abstract: A system having networked exercise devices that can have a shared virtual exercise session for training, collaboration or competition. The exercise devices each have adjustable difficulty setting and a touch screen for displaying different virtual exercise sessions. The touch screen can display a representation, such as one or more avatars, that represent users of the exercise devices, and that have a virtual speed in proportion to exercise performance on the exercise devices. Dynamic adjustment can be made based on the collective performance of the exercise devices, to cause a same adjustment to a respective current difficulty setting of at least one, two or more exercise devices during the shared virtual exercise session. Virtual training can be provided by way of a chaser animation that chases the representation of the exercise devices, the chaser animation having a virtual speed in dependence of exercise performance of users of the exercise devices.

Abstract: A frequency control apparatus includes a signal generator configured to generate an output signal as a digital signal having a target frequency that has been set, using a plurality of signals having frequencies that are different from the target frequency and one another, an estimator configured to estimate a mixed frequency that is a frequency of a signal component mixed in the output signal and different from the target frequency and each of frequencies of the plurality of signals, and a frequency shift unit configured to shift at least one of the target frequency and the frequencies of the plurality of signals in accordance with an estimation result of the mixed frequency.

Abstract: A risk-of-falling determination apparatus includes a walk information obtainer that obtains walk information of a user, a myoelectric sensor that measures a first myoelectric potential difference on an anterior surface of a thigh of the user and a second myoelectric potential difference on a posterior surface of the thigh, a control circuit that identifies an interval of a stance phase by using the walk information, calculates a degree of co-contraction at a corresponding leg of the user on the basis of the first and second myoelectric potential differences for the stance phase, and determines whether the degree of co-contraction is greater than or equal to a first threshold, and an outputter that outputs a signal indicating that the user has a high risk of falling if the degree of co-contraction is greater than or equal to the first threshold.

Abstract: A method for identifying human joint characteristics, the method including the steps of: placing an item with a known characteristic near the joint, using a mobile imaging device, taking at least one image of the joint, and using the image and the known characteristic of the item to determine a joint characteristic of the joint.

Abstract: An apparatus for monitoring a biosignal of a cyclist includes an electrocardiogram measuring sensor measuring an electrocardiogram signal of a cyclist, an electromyogram measuring sensor measuring an electromyogram signal of the cyclist, and a determination module determining muscle fatigue of the cyclist, based on at least one of a change in a heart rate of the measured electrocardiogram signal and a change in a frequency component of the measured electromyogram signal.

Abstract: The disclosed embodiments include user fatigue level analysis components, real-time visual behavior measuring devices, and methods for determining the fatigue level of a user. In one embodiment, a user fatigue level analysis component includes a memory configured to store computer executable instructions and a processor for executing the computer executable instructions. The computer executable instructions comprise instructions for receiving at least a visual behavior parameter indicative of the real time visual behavior of the user, for providing at least one sleep quality history parameter indicative of the sleep quality history of the user, and for determining the fatigue level of the user based on the analysis of the combination of the at least one visual behavior parameter and the at least one sleep quality history parameter.

Abstract: A non-invasive and accurate vagina evaluation device and uterine evaluation devices are provided that measure the receptivity (uterine implantation capacity) of the mother's body to a fertilized egg implanting itself into the uterus. A first vagina evaluation device includes: a main body stretchable and expandable after insertion into a vagina, followed by air injection thereinto; four electrodes brought into contact with the vagina wall as the main body expands and stretches; and a fixation device configured to fix the interval of arrangement of the electrodes. Second and third uterine evaluation device include: a flexible and rod-shaped main body for insertion into a uterine cavity; and four or two impedance electrodes arranged with a predetermined interval therebetween in an insertion direction of the main body and brought into contact with an endometrium of the uterine cavity to measure a uterine endometrial impedance generated between the endometrium and each of the electrodes.

Abstract: The invention relates to a method with biofeedback for training muscles of the pelvic floor, applicable to the treatment of urinary incontinence, fecal incontinence and prolapse of pelvic organs, using a portable electronic device for capturing, by means of sensors, EMG signals relating to abdominal activity and the area to be treated during muscle exercises, said device providing results visually and/or acoustically, the method comprising: placing a vaginal or rectal sensor (10) and two sensors (11) in the lower abdominal area, performing exercises working the muscles of the pelvic floor, providing evaluation of the exercises performed and storing results. The user places the sensors herself, the device evaluating the correct placement of the sensors indicating to the user that the suitable position has been reached through said acoustic and/or visual means, and performing a step prior to the exercises for acquiring muscle tone.

Abstract: A system and method are provided that employ a monitoring device to monitor at least one patient physiological response to a change in temperature of the patient (e.g. pursuant to induced hypothermia therapy), wherein a monitoring signal is provided by the monitoring device. In turn, an output (e.g. a visual and/or auditory output) may be provided to a user indicative of at least one measure of patient response to the change in temperature. Alternatively or additionally, a processor may be provided to process the monitoring signal and provide an output employable by medical personnel to control a patient shivering response to the patient temperature change. Such information may comprise information regarding one or more anti-shivering medicament(s), e.g. corresponding dosage and/or frequency information for use by medical personnel in the administration of the anti-shivering medicament.

Abstract: Disclosed is a vascular image positioning system, including an image enhancing device (1) and an image projection device (2) used cooperatively with the vascular image enhancing device (1). The transmission light emitted by the enhancing device (1) passed through the sites of the human body surface to be tested, is received by the image projection device (2), and after image processing, forms in situ images at sites on the surface of the skin of the human body to be tested. The enhancing device (1) comprises a light emitting unit (101) and a drive unit (102) driving the light emitting unit (101) to emit light. The vascular image positioning system provides the function of using a transmission light source to achieve in situ imaging of the blood vessels at the sites to be tested; secondly, it also provides a mode for combining a transmission light source with a reflection light source, thereby strengthening the function of in situ imaging and widening the application range.

Abstract: Disclosed is a method of identifying a parameter of a characteristic of a muscle, and walking assistance apparatuses and method based on the method. The method of identifying a parameter of a characteristic of a muscle includes estimating a first torque of a joint based on an electromyogram (EMG) signal, estimating a second torque of the joint based on motion data, and identifying a parameter of a characteristic of a muscle associated with the joint based on the first torque and the second torque.

Abstract: Provided are an photic stimulation device, method, and program, including a waveform generation unit configured to shape a waveform of a frequency band including a part of a band of ? waves and a part of a band of a waves; a pulse modulation unit configured to generate a pulse waveform with duty adjusted on the basis of an amplitude of the waveform generated by the waveform generation unit; and a light exposing unit configured to irradiate a head with a red pulsed beam on the basis of an output of the pulse modulation unit.

Abstract: System and methods for acquiring and processing myoelectrical data from the gastrointestinal tract of a patient are provided. In various embodiments, the systems and methods monitor the motor activity of a patient recovering from surgery to detect a resumption in gastrointestinal motility. In some embodiments, the systems and methods enable proper post-operative ileus in the patient. In some embodiments, the systems and methods allow researchers or clinicians to determine the efficacy of one or more therapies intended to encourage gastrointestinal motility. In some embodiments, the systems and methods enable clinicians to predict and facilitate the proper timing of discharge from a healthcare facility following surgery.

Abstract: A system and method for profiling electrical activity in smooth muscle of the gastrointestinal tract muscular of a patient are disclosed. The system includes electromyographic-sensing patches adapted for placement on the skin of the abdomen of the patient. Each patch has at least one bipolar electrode pair, or a multitude arranged in an array, and is enabled for communication of a signal indicative of a sensed electromyographic signal. The system further includes networked computing devices. The local patch device is configured for wireless communication between the EMG-sensing patches and a local computing device, to enable wireless transmission from the patch to the networked computing devices. The networked computing device is configured to process large aggregate collections of multi-hour or day signals received from the local computing device to yield diagnostically valuable physiological parameters of gastrointestinal smooth muscle electrical activity.

Abstract: Methods and apparatus for calibrating performance of one or more statistical models used to generate a musculoskeletal representation. The method comprises controlling presentation of instructions via a user interface to instruct the user to perform the at least one gesture and updating at least one parameter of the one or more statistical models based, at least in part on a plurality of neuromuscular signals recorded by a plurality of neuromuscular sensors during performance of the at least one gesture by the user.

Abstract: The present disclosure relates to sensor systems for electronic ophthalmic devices. In certain embodiments, the sensor systems may comprise a vibration sensor disposed adjacent an eye of a user, the vibration sensor configured to detect a vibration caused at least in part by ciliary muscle movement, the vibration sensor further configured to provide an output and a processor configured to receive the output and to determine a characteristic of the output indicative of the ciliary muscle movement.

Abstract: A sleeve worn on an arm allows detection of gestures by an array of sensors. Electromyography, inertial, and magnetic field sensors provide data that is processed to categorize gestures and translate the gestures into commands for robotic systems. Machine learning allows training of gestures to increase accuracy of detection for different users.

Abstract: A diagnosis device, and more particularly, a compartment syndrome diagnostic device is described herein. The diagnostic device may include a display that renders information associated with stimulation of a motor unit suspected of suffering from compartment syndrome. The diagnostic device may generate a stimulation signal for stimulating the motor unit through an electrode. The device may determine whether the motor unit is at risk for compartment syndrome based on the response of the motor unit to the stimulation. The diagnostic device may also measure pressure of a compartment. The device may determine whether the motor unit is at risk for compartment syndrome based on the measured pressure and the response of the motor unit to the stimulation.

Abstract: A method for clustering of transient signals is provided. The method comprises the steps of acquiring the transient signals as they come, dynamically building up clusters of similar transient signals in a hyperspace based on comparison and clustering rules so that each new one of the transient signal acquired ends up in a cluster with similar transient signals formerly acquired, analyzing the clusters to determine respective signatures defined by the transient signals gathered in the clusters, and processing the signatures to detect a phenomenon connectable to an intrinsic attribute of the transient signals.

Abstract: A nerve integrity monitoring device includes a control module and a physical layer module. The control module is configured to generate a payload request. The payload request (i) requests a data payload from a sensor in a wireless nerve integrity monitoring network, and (ii) indicates whether a stimulation probe device is to generate a stimulation pulse. The physical layer module is configured to (i) wirelessly transmit the payload request to the sensor and the stimulation probe device, or (ii) transmit the payload request to a console interface module. The physical layer module is also configured to, in response to the payload request, (i) receive the data payload from the sensor, and (ii) receive stimulation pulse information from the stimulation probe device. The data payload includes data corresponding to an evoked response of a patient. The evoked response is generated based on the stimulation pulse.

Abstract: A method, system and apparatus for determining the state of a muscle between a normal non-tired state, a tired state and a passive involuntary tension state. A signal from the muscle is recorded at rest by using an electrode arrangement, where an earth body may prevent the electrodes from picking up signals beyond the extent of the earth body. The frequency content of the signal is determined by spectral analysis, e.g. by computing a moment of the spectrum. A normal frequency content indicates a non-tired muscle state, whereas a low and a high frequency content indicate a tired and a passive involuntary tension muscle state.

Abstract: An evoked potential monitoring system including a control unit having stimulator circuitry and a probe assembly coupled to the control unit. The probe assembly includes a stimulus probe and a stimulator handpiece selectively coupled to the stimulus probe. The handpiece includes a handle, control circuitry, and a switch. The control circuitry is electrically coupled to the stimulator circuitry. The switch is electrically coupled to the control circuitry and extends to an exterior portion of the handle. In this regard, movement of the switch remotely controls the stimulator circuitry to continuously increment or decrement a stimulation energy level delivered to the stimulus probe over a series of discrete, incremental steps.

Abstract: The present invention has an objective of evaluating a motor function of a subject with a neurodegenerative disease with high accuracy using a motor function analysis system that utilizes a wrist joint movement of the subject. The motor function analysis system includes: a display unit for displaying image information including a moving target image and a cursor image for tracking the target image; a moving unit used by the subject to move the cursor image; and an analyzer for detecting the tracking status of the target image tracked by the cursor image and analyzing the frequency of the movement components contained in the tracking status.

Abstract: A device for treating sleep apnea by discriminating between successive sleep stages of a patient includes a generator configured to produce stimulation pulses, a stimulator that receives the stimulation pulses produced by the generator and delivers stimulation to the patient, a sensor configured to measure a biological parameter of the patient, and a controller. The controller is configured to determine a state of the patient based on the biological parameter, perform a sleep analysis based on the state of the patient, activate the generator to trigger production of the stimulation pulses, determine a variation of the biological parameter subsequent to the production of the stimulation pulses, determine a response of the patient to the stimulation pulses according to the variation of the biological parameter, and determine a sleep stage of the patient based on the response.

Abstract: The present disclosure relates to various methods for determining a neuromuscular blockade status and systems suitable for performing such methods. The present disclosure further relates to electro-stimulation electrodes for stimulating a muscle of a patient, optionally in the context of at least some of the mentioned methods. The present disclosure still further relates to hybrid air-signal connectors for use in an electro-stimulation cuff which can be used in the context of at least some of the cited methods. The present disclosure also relates to electro-stimulation circuits comprising an electrode portion and a track portion suitable for pressure cuffs for electro-stimulation, and to pressure cuffs configured to be arranged around a limb of a patient and comprising an active electro-stimulation electrode and a passive electro-stimulation electrode. These electro-stimulation circuits and pressure cuffs may also be used in the context of at least some of the mentioned methods.

Abstract: A wearable device has a core contraction sensor and a movement sensor which transmits signals to a processor which analyzes the signals. The core contraction signal may determine if the user's core is contracted or relaxed. A video camera on a smart device may be used with the wearable device to record video of a user while data from the sensors on the wearable device are also recorded. The core contraction and movement sensor data may be sent to and viewed on the smart device display together with video of the user performing a movement. The simultaneous viewing of the video and sensor data may provide immediate feedback to the user regarding the timing of core contractions with body movements in an athletic, training, or therapeutic movement to allow the user to modify and improve coordination of core contraction with body movements to improve movement performance and achieve better results.

Abstract: Systems and methods are provided for determining performance capacity. One such system includes a wearable device having a biosensor that measures biometrics and a motion sensor that monitors activity. The system also includes a processor coupled to the biosensor and the motion sensor, and a non-transitory computer-readable medium operatively coupled to the processor and storing instructions that, when executed, cause the processor to execute specific functions. The instructions are executed to cause the processor to generate biometric data from the biometrics and activity data from the activity. Further, the instructions are executed to create a response profile based on one or more of a heart rate variability (HRV) score based on the biometric data, a fatigue score based on the activity data, a predicted HRV score based on the biometric and activity data, and a predicted fatigue score based on the biometric data and/or the activity data.

Abstract: A system for treating a patient with neurological disorders of movement includes a patient computing device for use in rehabilitative training and a sensor worn about a body part being rehabilitated. A healthcare computing device is used by a healthcare professional to assist remote patient rehabilitation by accepting input signals and determining for the patient a rehab protocol depending on selected parameters, and determining for the patient a behavior shaping target depending on selected parameters and the rehab protocol and behavior shaping target is communicated to the patient while the patient is undergoing rehabilitation. A plurality of remote health data sites and other public repositories of health data of patients undergoing rehabilitation following neurological events can be included. The remote computing device can include a data repository of publicly available patient data and patient data gathered by system of present invention.

Abstract: In an approach to generating preflex stimulation, one or more computer processors monitor one or more sensing devices for data associated with a user activity. Based, at least in part, on the data associated with the user activity, the one or more computer processors predict a user reaction associated with the user activity. The one or more computer processors transmit a preflex stimulus to at least one muscle of the user, wherein the at least one muscle is associated with the user reaction. The one or more computer processors determine a reaction time of the at least one muscle to the preflex stimulus.

Abstract: A method for external ear canal pressure regulation to alleviate one or more symptoms associated with a disorder or treat one or more disorders, the method including providing a fluid transfer device which generates a fluid flow of a fluid through an earplug, the earplug having an earplug external surface configured to sealably engage an external ear canal wall as a barrier between an external ear canal pressure and an ambient pressure; sealably engaging the earplug of the fluid transfer device with the external ear canal wall as the barrier between the external ear canal pressure and the ambient pressure; and operating the fluid transfer device to generate the fluid flow of the fluid through the earplug to achieve an external ear canal pressure differential between the external ear canal pressure and the ambient pressure effective to alleviate a disorder symptom or treat a disorder.

Abstract: Various embodiments are directed to signal processing. In accordance with example embodiments, methods and apparatuses involve using at least two electrodes that sense an ECG signal. A denoising module is communicatively coupled to the at least two electrodes, and receives the ECG signal sensed by the sensing electrodes. The denoising module includes circuitry that conditions and digitizes the ECG signal, and a computing circuit that processes the digitized ECG signal to denoise the ECG signal. A communications circuit generates a communication including the denoised ECG signal for access by a remote device.

Abstract: Systems, devices, and methods that implement state machine models in wearable electronic devices are described. A wearable electronic device stores processor-executable gesture identification instructions that, when executed by an on-board processor, enable the wearable electronic device to identify one or more gesture(s) performed by a user. The wearable electronic device also stores processor-executable state determination instructions that, when executed by the processor, cause the wearable electronic device to enter into and transition between various operational states depending on signals detected by on-board sensors. The state machine models described herein enable the wearable electronic devices to identify and automatically recover from operational errors, malfunctions, or crashes with minimal intervention from the user.

Abstract: A myoelectric computer interface device is disclosed that includes a myoelectric controller, a computer interface and a monitor. The computer interface includes at least one computer-implementable software program that comprises executable code, wherein the executable code comprises at least one member selected from the group consisting of: instructions for mapping at least one muscle activity to cursor icon movement and instructions for orthogonal or other mapping of co-activated muscles.

Abstract: A peripheral nerve stimulator can be used to stimulate a peripheral nerve to treat essential tremor, Parkinsonian tremor, and other forms of tremor. The stimulator can have electrodes that are placed circumferentially around the patient's wrist or arm. Specific nerves in the wrist or arm can be targeted by appropriate spacing of the electrodes. Positioning the electrodes on generally opposing sides of the target nerve can result in improved stimulation of the nerve. The stimulation pattern may alternate between the nerves. Improved stimulation algorithms can incorporate tremor feedback, external data, predictive adaptation, and long-term monitoring data.

Abstract: Patients afflicted by a seizure may be monitored for the presence of post-ictal motor manifestations that may indicate that the patient is at heightened risk of adverse effects of a seizure, including, for example, risk of sudden explained death in epilepsy. If the patient is deemed to be at risk of experiencing adverse effects of a seizure, one or more system responses may be initiated as appropriate for the at-risk patient.

Abstract: The present application relates generally to computer software, mobile electronics, wireless communication links, and wearable monitoring systems. More specifically, techniques, systems, sensors, circuitry, algorithms and methods for wearable monitoring devices and associated exercise apparatus are described. A garment borne sensor system may acquire data on a user's performance during exercise, for example. The data may be analyzed in real time and feedback may be provided to the user based on the analysis. Analysis may be used to alter behavior of the user and/or an apparatus the user is engaged with during an activity, such as exercise, conditioning, therapy, etc. A piece of exercise equipment may be instrumented and in communication with the sensor system or other system and may be controlled in real time to adjust its settings to affect the user during the exercise routine. Communication between the sensor system and other systems may be wireless.

Abstract: An automated adaptive muscle stimulation system and method are disclosed. The stimulation system includes at least one electrode assembly adapted to deliver a muscle stimulation signal to the tissue of a user, a sensor system adapted to detect a muscle response, and an electrical stimulation device operably coupled to the at least on electrode assembly and the sensor system, the electrical stimulation device including a control system operable to automatically diagnose at least one characteristic of a muscle from the detected muscle response and adjust at least one parameter of the muscle stimulation signal in response thereto to deliver an adjusted muscle stimulation signal. A dual mode muscle stimulation system adapted to accept first and second data sets and provide first and second levels of treatment data is also disclosed.

Abstract: Provided is a perineal probe for asymmetric treatments extending primarily along a longitudinal axis and including: a main rod extending primarily along the longitudinal axis; a plurality of electrodes, the perpendicular projection of which along said longitudinal axis is substantially in the same position, and reciprocally spaced in directions perpendicular to the longitudinal axis and connected to the main rod by means of deformable arms, and sensing means to detect the deformation of the arms.