Abstract: A therapeutic member for use in brachytherapy deliverable to an implant site by way of a needle comprises a single radioactive source encapsulated by a bio-absorbable material having an outer surface including one or more ribs encircling the single radioactive source, a leading edge endcap rib and a trailing edge endcap rib. The one or more ribs reduces a tendency of the member to migrate and rotate within a patient's body after implantation. The encapsulating material further includes a first rail formed from the bio-absorbable material extending at least from opposite sides of the outer surface of the encapsulating material along the longitudinal axis of the therapeutic member, and a second rail formed from the bio-absorbable material extending at least from opposite sides of the outer surface of the encapsulating material along the longitudinal axis of the therapeutic member, the second rail arranged in a plane substantially perpendicular to a plane in which the first rail is arranged.

Abstract: An axial-flow blood pump for pumping blood includes a substantially cylindrical outer enclosure. A tubular housing concentric with and located within the outer enclosure has at one end an inlet and at an opposite end an outlet. A motor stator is concentric with and located between the outer enclosure and the tubular housing. An impeller is concentric with and located within the tubular housing. The impeller is suspended in operation by a combination of passive magnetic forces between magnets within the impeller or magnetized regions of the impeller and the motor stator and hydrodynamic thrust forces generated as blood flows between the tubular housing and a plurality of hydrodynamic thrust bearing surfaces located on the impeller. A volute may be in fluid-tight connection with the outlet of the tubular housing for receiving blood in the axial direction and directing blood in a direction normal to the axial direction.

Abstract: An implantable hearing prosthesis comprising a vibrator for generating vibrations, a coupling arm adapted to be attached to an element of a recipient's ear; and a quick-connector comprising a first connector half disposed on the vibrator and a second connector half disposed on the coupling arm, wherein the connector halves are adapted to be releasably mated with one another to secure the coupling arm in relative position to the vibrator.

Abstract: The invention, in various embodiments, provides systems, devices, and methods for treating urinary incontinence.

Abstract: The invention, in various embodiments, provides systems, devices, and methods for treating urinary incontinence. The invention also provides a driver and methods for advancing needles, cannulas, and other medical devices through the pubic bone. The driver may be used in connection with a driver frame assembly for proper positioning and stabilization of the driver, and with other devices for creating a cavity in the urethral floor and for positioning medical devices therein. The invention also provides simple connections for attaching a suture to a device within the cavity in the urethral floor or in the vagina, an also for attaching sutures to the pubic bone.

Abstract: In a general aspect, a method of treating urinary incontinence can include slidably interfitting a first push tube into a first dilator tube disposed at an end of a sling assembly and slidably interfitting the first push tube onto an end of a shaft of a delivery device. The method can also include inserting the shaft transvaginally through a vaginal wall and removing the shaft to implant a portion of the sling assembly in periurethral tissue. The method can also include slidably interfitting a second push tube into a second dilator tube disposed at a second end of the sling assembly and slidably interfitting the second push tube onto the end of the shaft. The method can still further include inserting the shaft transvaginally through the vaginal wall and removing the shaft from the patient to implant a second portion of the sling assembly in periurethral tissue.

Abstract: A method for making a radially expandable stent-graft, including positioning a radially expandable stent member concentrically over a first polymeric member, locating a second polymeric member concentrically over the stent member and first polymeric member, and joining the first polymeric member to the second polymeric member through interstices of the stent member at selective locations to form slip planes between the first and second polymeric members. The slip planes accommodate movement of the stent between the polymeric members to facilitate compression of the stent graft to a low profile.

Abstract: Devices and systems including implants (which may be removable) and methods of using them for reducing ventricular volume. The implants described herein are cardiac implants that may be inserted into a patient's heart, particularly the left ventricle. The implant may support the heart wall, or may be secured to the heart wall. The implants are typically ventricular partitioning device for partitioning the ventricle into productive and non-productive regions in order to reduce the ventricular volume.

Abstract: The present invention is directed to a tool having a wrist mechanism that provides pitch and yaw rotation in such a way that the tool has no singularity in roll, pitch, and yaw. In one embodiment, a minimally invasive surgical instrument includes an elongate shaft having a working end, a proximal end, and a shaft axis between the working end and the proximal end; and an end effector. A wrist member has a flexible tube including an axis extending through an interior surrounded by a wall. The wall of the flexible tube includes a plurality of lumens oriented generally parallel to the axis of the flexible tube. The wrist member has a proximal portion connected to the working end of the elongate shaft and a distal portion connected to the end effector.

Abstract: The present invention provides a gas water bottle adaptor that is suitable for attachment to a water bottle and to a bottle cap. The adaptor can include a gas inlet on one side thereof suitable for attachment to the gas connection of an endoscope. A sealing member can be affixed to the adaptor to prevent leakage of any fluid (e.g., liquid or gas) that is inside of the water bottle. The adaptor may be used in endoscopy methods and is particularly useful for adding a secondary gas source to a water bottle.

Abstract: A system for mini-invasive surgery in a body cavity that is easily positioned and hooked including at least one detachable surgical endoclamp (10), assembled with an introduction guide (20) and at an initially open position; and at a naturally closed position when detached from the introduction guide (20) by a detachment mechanism; the endoclamp (10) comprising a portion of ferromagnetic material; a cylindrically-shaped introduction guide (20) assembled with the detachable surgical endoclamp (10), the introduction guide (20) comprising a mechanism to detach the endoclamp (10); and at least one remote traction component (30) for the endoclamp (10), acting through the application of an electromagnetic field over the ferromagnetic portion of the endoclamp (10).

Abstract: A self-propelled device for locomotion through a lumen, comprising a set of serially arranged inflatable chambers, and incorporating a number of novel aspects. To enable easy insertion and use, the rigidity of the device is increased by means of rigid inserts in the balloons, or by use of stiff springs between segments. The working channel can be attached to the distal chamber of the device, such that it is pulled from the leading end of the device during inflation, rather than being pulled from the trailing end of the device during deflation. Lumen wall inspection or treatment facilities are enabled by means of a camera or treatment arm mounted between two distally positioned balloons, the device is able to provide observation capabilities to the lumen wall, yet without becoming excessively dirty by exposure to the front end of the device, as in prior art camera units.

Abstract: An object of the present invention is to actively control at least one of the position and direction of the imaging field in a subject and to observe a desired observed region in the subject certainly in a short period of time. A body-insertable device system according to the present invention includes a capsule endoscope 1 introduced into a subject and a permanent magnet 3. An imaging unit of the capsule endoscope 1 for taking an image inside the subject is fixed in a casing. The capsule endoscope 1 includes a drive unit for changing at least one of the position and posture of the casing in the liquid 2a which is also introduced in the subject 100. The permanent magnet 3 controls the operation of the drive unit for changing at least one of the position and posture of the casing in the liquid 2a.

Abstract: An indwelling apparatus (5) for holding a capsule endoscope (3) is arranged with a control device (57) including an optical sensor (73), a control board (66) configuring a controller and a reset circuit, a driver board (68) configuring an electromagnet driver, and an electromagnet (70), where when the optical sensor (73) detects the light, the controller performs the drive control of the electromagnet (70) at every constant time interval to turn ON the reed switch (14) and supply power to the capsule endoscope (3) thereby operating the capsule endoscope (3) only when observation is necessary, and thus the battery drain of the capsule endoscope is reduced.

Abstract: An endoscope includes a distal end portion body 31 formed of a metal, a distal end portion cover 32 formed of an insulating resin to cover the distal end portion body 31, and a cover lens 25 disposed at a position at which the circumferential surface of the cover lens 25 is contactable with both the distal end portion body 31 and the distal end portion cover 32. In the above, the proximal end side of the circumferential surface of the cover lens 25 is bonded to the distal end portion body 31 by soldering along the circumferential direction. Meanwhile, the distal end side of the circumferential surface of the cover lens 25 is bonded to the distal end portion cover 32 by adhesion along the circumferential direction. Each of bonding surfaces of the cover lens 25 and the distal end portion body 31 is previously formed with a metal film for improving the flow of a liquid solder.

Abstract: An endoscope (1) having a distal end being arranged to be inserted into a body cavity of a patient to be examined and a proximal end which is arranged to be held by a user of the endoscope. The endoscope further comprises a handle (2) arranged at the proximal end of the endoscope, an insertion portion (3) arranged at the distal end of the handle, a bending portion (4) arranged at the distal end of the insertion portion, and two control wires (40,41) arranged between the handle and the bending portion, said control wires being used to control the bending of the bending portion via control inputs made at the handle.

Abstract: In a special light mode, first to fourth special images are captured under first to fourth special light being narrow band light. A brightness ratio calculator extracts a blood vessel area containing a blood vessel from each special image. The brightness ratio calculator calculates first to fourth brightness ratios from the special images on every pixel within the blood vessel area. A depth and hemoglobin index calculator calculates the depth of the blood vessel and a hemoglobin index corresponding to the first and second brightness ratios, based on a correlation between the depth of the blood vessel and the hemoglobin index stored in advance. A depth and oxygen saturation calculator calculates an oxygen saturation level corresponding to the third and fourth brightness ratios, based on a correlation between the depth of the blood vessel and the oxygen saturation level stored in advance.

Abstract: Provided is an endoscope with a handle, an endoscope shaft connected to the handle, and imaging optics arranged in the endoscope shaft. An object can be located in the direction of view of the imaging optics in front of the endoscope shaft. The endoscope may also include a swivellably housed deflecting element that sets the desired direction of view. The deflecting element can be positioned at the distal end of the endoscope shaft facing away from the handle. An actuating element can be attached to the handle, which is mechanically connected to the deflecting element, and with which the swivel position of the deflecting element can be changed in order to set a desired direction of view.

Abstract: A light source device includes a first light source, a second light source having an emission wavelength that is different from the first light source, and a phosphor that is disposed to be distant from the first light source and the second light source and absorbs light in a predetermined excitation wavelength band to emit fluorescence. The phosphor is disposed on an emission light optical path that is shared by the first light source and the second light source. The emission wavelength of the first light source is in the predetermined excitation wavelength band. The emission wavelength of the second light source is outside of the predetermined excitation wavelength band.

Abstract: In a method and a device for determining the posture of a patient, a bio-impedance measurement device, having a number of electrodes configured to interact with the patient in a number of different electrode configurations, is operated to initiate a patient posture determining session by measuring an impedance value of the patient with the electrodes in at least one configuration among the number of configurations. A reference impedance value from among a number of stored reference impedance values for the at least one configuration is selected. The number of stored reference impedance values are respectively associated with different postures of the patient, and the posture associated with the selected reference impedance value represents a candidate posture. The measured impedance value is compared with the selected reference impedance value, thereby obtaining a comparison result.

Abstract: This invention provides user interfaces that more intuitively display physiological data obtained from physiological monitoring of one or more subjects. Specifically, the user interfaces of this invention create and display one or more avatars having behaviors guided by physiological monitoring data. The monitoring data is preferably obtained when the subject is performing normal tasks without substantial restraint. This invention provides a range of implementations that accommodate user having varying processing and graphics capabilities, e.g., from handheld electronic devices to ordinary PC-type computers and to systems with enhanced graphics capabilities.

Abstract: Disclosed are systems and methods for enabling the acquisition of physiological parameters of a mammal or other specimen using thermo-mechanical responses (e.g., temperature, pressure and alternatively acceleration, pulse, position). In accordance with one example embodiment, a monitoring device for wired and/or wireless sensors is used to acquire a series of sensor signals that are attached to achieve the physiological measurements of a mammal vital signs is provided. The device includes a Temperature-Pressure (T-P) sensor configured to attach to respiration, vascular pressure and audio points of the mammal in a manner suitable for obtaining the acquired individual sensor electrical signal. The sensor system is configured to attach to alternative locations of the specimen in a manner suitable for obtaining electrical signals in communication with a signal receiver and transmitter. Physiological parameters, such as those associated with vital signs (temperature, pulse, respiration, etc.

Abstract: Systems and methods of detecting an impending cardiac decompensation of a patient measure at least two of an electrocardiogram signal of the patient, a hydration signal of the patient, a respiration signal of the patient or an activity signal of the patient. The at least two of the electrocardiogram signal, the hydration signal, the respiration signal or the activity signal are combined with an algorithm to detect the impending cardiac decompensation.

Abstract: Instrumented orthoses with more sophisticated structures provide for coordinated support and rehabilitation of complex joints and multiple injured joints. Improved instrumented orthoses can include hinges that can rotate in multiple different planes. Particularly preferred embodiments include a shoulder brace with a hand hold and a lower extremities brace. Preferably, a control unit monitors the output Of transducers used to instrument the brace. A patient can be prompted by the control unit for the performance of a variety of different monitored exercises.

Abstract: Methods and apparatus to determine the presence of and track functional chronotropic incompetence (hereinafter “CI”) in an in-home setting under conditions of daily living. The functional CI of the patient may be determined with one or more of a profile of measured patient heart rates, a measured maximum patient heart rate, or a peak of the heart rate profile. The functional CI of the patient may be determined with the measured heart rate profile, in which the measured heart rate profile may correspond to heart rates substantially less than the maximum heart rate of the patient, such that the heart rate can be safely measured when the patient is remote from a health care provider. The functional CI of the patient may be determined based a peak of the remotely measured heart rate profile, for example a peak corresponding to the mode of the heart rate distribution profile.

Abstract: Systems and methods for minimizing or eliminating transient non-glucose related signal noise due to non-glucose rate limiting phenomenon such as ischemia, pH changes, temperatures changes, and the like. The system monitors a data stream from a glucose sensor and detects signal artifacts that have higher amplitude than electronic or diffusion-related system noise. The system replaces some or the entire data stream continually or intermittently including signal estimation methods that particularly address transient signal artifacts. The system is also capable of detecting the severity of the signal artifacts and selectively applying one or more signal estimation algorithm factors responsive to the severity of the signal artifacts, which includes selectively applying distinct sets of parameters to a signal estimation algorithm or selectively applying distinct signal estimation algorithms.

Abstract: A continuous, noninvasive fetal heart rate measurement is produced using one or more ultrasonic transducer adhered to the abdomen of the mother. Each ultrasound transducer generates an ultrasound beam having a signal strength. The signal strength is determined by an excitation voltage applied to the ultrasound transducer. An excitation voltage adjustment device is positioned between an excitation voltage generator and the ultrasound transducer to selectively control the strength of the ultrasound beam. A user input device allows an operator to control the ultrasound signal strength to vary the depth of viewing of the fetal heart rate monitor.

Abstract: A method for implementing an imaging and navigation system to perform a medical procedure such as cardiac ablation is disclosed herein. The a method includes implementing an ultrasonic imaging device to provide a generally real time three-dimensional patient image, identifying a target site on the generally real time three-dimensional patient image, directing a medical instrument to the target site using a tracking system, and performing a medical procedure at the target site.

Abstract: The embodiments contemplate systems and methods for detecting moving tissue within an object. In one such method, a first and second ultrasound pulse are transmitted at a first sample volume within an object. A first echo signal of the first ultrasound pulse is received from the first sample volume and a second echo signal of the second ultrasound pulse is received from the first sample volume. An estimate of position displacement data of the first sample volume is computed from the first and second echo signals, and the estimate of position displacement data is compared to a predetermined position displacement data threshold indicative of moving tissue. A determination is made, based on the comparison, whether the first sample volume corresponds to moving tissue and, based on the determination, the transmitting, receiving, computing and determining is repeated for a second sample volume.

Abstract: Apparatus and methods for vibro-acoustic detection of cardiac conditions are disclosed. An example method includes calculating a frequency difference between a first frequency of a first cardiac signal and a second frequency of a second cardiac signal; calculating an amplitude difference between the first cardiac signal and the second cardiac signal; calculating a root-mean-square value based on a difference between the first cardiac signal and the second cardiac signal; calculating a value based on the frequency difference, the amplitude difference, and the root-mean-square value; and detecting a cardiac condition based on the value.

Abstract: In a method for intermittently occluding the coronary sinus, in which the coronary sinus is occluded using an occlusion device, the fluid pressure in the occluded coronary sinus is continuously measured and stored, the fluid pressure curve is determined as a function of time, and the occlusion of the coronary sinus is triggered and/or released as a function of at least one characteristic value derived from the measured pressure values. The pressure increase and/or pressure decrease per time unit each occurring at a heart beat are used as characteristic values.

Abstract: A system for remote ischemic preconditioning that includes a cuff, and actuator, and a controller that operates the actuator according to a treatment protocol. The treatment protocol includes a plurality of treatment cycles that each comprise cuff actuation, an ischemic duration, cuff release, and a reperfusion duration.

Abstract: A method of processing a signal pertaining to at least one electrical property of an organ of a subject is disclosed. The method comprises determining a physiological condition of the subject, selecting a frequency band, filtering the signal according to the frequency band, and dynamically adapting the frequency band in response to a change in the physiological condition.

Abstract: A patient monitor for displaying a physiological signal can include a visual element having a middle portion indicative of a transition in the physiological signal between physiological states. The visual element can also include first and second extremity portions, the first extremity portion extending from the middle portion in a first direction and the second extremity portion extending from the middle portion in a second direction. The visual element can also include an actionable value indicator to specify a value about the middle portion and the first and second extremity portions. The patient monitor can also include a processor configured to cause the value indicator to actuate in both the first and second directions according to changes in the physiological signal.

Abstract: What is disclosed is a system and method for monitoring respiration of a subject or subject of interest using a thermal imaging system with single or multiple spectral bands set to a temperature range of a facial region of that person. Temperatures of extremities of the head and face are used to locate facial features in the captured thermal images, i.e., nose and mouth, which are associated with respiration. The RGB signals obtained from the camera are plotted to obtain a respiration pattern. From the respiration pattern, a rate of respiration is obtained. The system includes display and communication interfaces wherein alerts can be activated if the respiration rate falls outside a level of acceptability. The teachings hereof find their uses in an array of devices such as, for example, devices which monitor the respiration of an infant to signal the onset of a respiratory problem or failure.

Abstract: A method of monitoring lung ventilation of a subject is disclosed. The method comprises recording signals from a plurality of sensing location on the chest of the subject, at least a portion of the signals being indicative of a local motion of the chest at a respective sensing location. The method further comprises operating a data processing system to analyze the signals such as to determine a status of the ventilation, thereby to monitor the lung ventilation of the subject.

Abstract: A portable device for measuring a consumed calories includes: a respiration measurement device measuring an amount of air inhaled into a user's nose to acquire and output a respiration signal; a plurality of movement detection devices acquiring and outputting acceleration signals reflecting (or indicating) the magnitude and direction of a movement of each part of the user's body; and a controller recognizing the amount of a user's movements and movement patterns by analyzing the acceleration signal, recognizing an intensity of an exercise by analyzing the respiration signal, and calculating a consumed calories in consideration of the amount of the user's movements, the movement patterns, and the intensity of exercise. A user's consumed calories can be precisely calculated by recognizing the user's movement and even the user's respiration rate.

Abstract: A method for determining cardiac parameters of a subject includes receiving a signal from a thoracocardiograph (TCG) sensor. The signal is sensitive to positions and/or motions of an anterior chest wall of the subject and include a cardiac component, a respiratory component, and noise and/or artifact components. The method also includes receiving one or more electrocardiogram (ECG) signals and filtering the received TCG signal to limit one or more of the respiratory component and the noise and/or artifact components. The filtering includes one or more of wavelet de-noising, non-linear filtering, and state space filtering. The method further includes ensemble averaging thefiltered TCG signal. Ensemble members are triggered by occurrence of one or more selected fiducial points determined in the ECG signal. Additionally, the method includes extracting parameters of cardiac functioning from the ensemble averaged signal.

Abstract: A pulmonary ventilation system comprising a method to determine at least one pulmonary ventilation parameter as a function of a plurality of measured anatomical distances and volume-motion coefficients, sensors for acquiring the anatomical distances, a device for determining the plurality of motion coefficients, and a device for determining the ventilation parameter based on the acquired anatomical distances and determined plurality of volume-motion coefficients. In one embodiment, the system further includes a method for acquiring base-line ventilation characteristics and a method for correlating the base-line ventilation characteristics to the ventilation parameter determined with the empirical relationship.

Abstract: A method and system of simultaneously monitoring body position and respiration of a subject are provided. The end-expiratory value of an axial dimension of a distance Xi between a first location and a second location is monitored for the subject orientation, and is then assigned a body position for the subject orientation during a calibration maneuver in which the subject is asked to assume various body positions. The transient voltage spikes in Xi voltage are measured to determine when the subject orientation changes. Following the subject orientation change, the stable end-expiratory voltage is determined to define a new body position. The new body position is outputted to a data output interface communicating with varied output devices.

Abstract: A system and methods that provide for visualization and/or characterization of manometry data. Visual representations of pressure information represent pressure information measured over time by sensors positioned within an organism. Markers may be provided on the visual representations. Using the system and methods described herein, various characteristics of an organism and/or events that occur within the organism may be determined.

Abstract: A biopsy system includes a cannula, a cutter, and a tissue sample holder. The cannula includes a closed distal end and a lateral tissue receiving port. The cutter is coaxially disposed with the cannula for severing tissue received in the tissue receiving port. The tissue sample holder includes a plurality of discrete tissue sample compartments. The biopsy system transports individual tissue samples to the discrete tissue sample compartments of the tissue sample holder.

Abstract: A urine collection system includes an anti-flux mechanism to reduce the amount of urine that may flow from within the collection bag back into the urine meter. The urine collection system includes a urine meter, a collection member defining at least a first opening for receiving urine from the urine meter and a shield positioned adjacent the opening of the collection member. The shield is affixed to the collection member at predetermined connection points along a periphery of the shield whereby urine flows between the connection points from the urine meter to the collection member. The shield may be affixed to an internal surface of the bag. The shield may be spot welded to the collection member at the connection points. The shield may include at least a first slot configured to permit the passage of fluid therethrough.

Abstract: An orthopaedic device for generating one or more strain signals representative of the strain in a bone in response to a force applied to the bone. The device includes an encircling member (11) for encircling the bone of a subject and a sensor member (13) connected thereto, the sensor member including a strain sensor (14). In a preferred embodiment the strain sensor comprises one or more bridging members configured to break when subjected to a particular strain.

Abstract: A gait analysis system for training or rehabilitation has an endless belt with pressure sensors underneath the belt to sense a person walking on the belt and an analyzing unit for analyzing the gait of the person. The system further includes an image display system with stored data for displaying images to a person using the apparatus training and/or therapy purposes.

Abstract: To provide a human state estimating device which accurately estimates a human state. The human state estimating device includes: a storage unit (16) which stores reference data (17) in which a human state and a reference profile including a horizontal component of a standard microsaccade in the human state are corresponded to each other, for each of plural personal attribute information; a video obtaining unit (11) which obtains video of a user's eyeball, with an eyeball rotation angle accuracy of 0.

Abstract: A high-power ultrasound heating applicator for minimally-invasive thermal treatment of uterine fibroids or myomas. High-intensity interstitial ultrasound, applied with minimally-invasive laparoscopic or hysteroscopic procedures, is used to effectively treat fibroids within the myometrium in lieu of major surgery. The applicators are configured with high-power capabilities and thermal penetration to treat large volumes of fibroid tissue (>70 cm3) in short treatment times (3-20 minutes), while maintaining three-dimensional control of energy delivery to thermally destroy the target volume.

Abstract: A neuromorphic controlled powered orthotic and prosthetic system and device including a custom or universal fit fixed-ankle orthosis, to stabilize or immobilize an injured lower limb or act as an ankle prosthesis, and an actuated or powered articulated false-foot connected to the fixed-ankle orthosis or the prosthesis to form an actuated articulated false-foot orthosis. Associated with or mounted on the actuated articulated false-foot, or in or on the body, are sensors for sensing the intent of the subject to move, and the movement range of the articulating false-foot or AAFO and an environmental perturbation. An actuator is used to drive the articulated false-foot orthosis. The system and device further include a controller having an electronic circuit with a biomimetic design based on knowledge of connectivity of neurons within the spinal cord of a primitive vertebrate.

Abstract: A fitness/medical device assisting the movement of the lower limbs during the walking activity is substantially composed of brackets firmly connected to the shoes, a set of substantially rigid rods (7, 7A) connecting the brackets with articulation joints (6, 6A, 8, 8A, 9), elastic or inextensible cables for connecting the brackets, and at least one spring (5) acting between the rods and the connecting cables. The shape and joints of the various components of the kinematic mechanism allows accumulating the energy produced by one of the lower limbs when getting in contact with the ground, in order to give it back to the other lower limb when lifting from the ground, so producing a great reduction of the energy needed in the walking activity and at the same time promoting the acquisition of a correct posture.

Abstract: A wheelchair type robot for use as a walking aid wherein an outer skeleton to be worn on the lower body of a user is combined with a lift and a drive part in a wheelchair form. The drive part is furnished with a drive motor and wheels that are installed on a main frame. The lift is furnished with an outer linear guide that is fixed and joined with the main frame, an inner linear guide that can move up and down along same, an upper chair part that connects with the inner linear guide to enable up and down motion, and a lower chair part that connects with the outer linear guide such that unfolds if the inner linear guide descends and folds if it ascends.