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[en] The objective of this paper is to examine the Pulse Transit Method (PTT) as a non-invasive means to track Blood Pressure over a short period of time. PTT was measured as the time it takes for an ECG R-wave to propagate to the finger, where it is detected by a photoplethysmograph sensor. The PTT method is ideal for continuous 24-hour Blood Pressure Measurement (BPM) since it is both cuff-less and non-invasive and therefore comfortable and unobtrusive for the patient. Other techniques, such as the oscillometric method, have shown to be accurate and reliable but require a cuff for operation, making them unsuitable for long term monitoring. Although a relatively new technique, the PTT method has shown to be able to accurately track blood pressure changes over short periods of time, after which re-calibration is necessary. The purpose of this study is to determine the accuracy of the method.
[en] Bellows are frequently required in accelerators and colliders. Usually RF-shields with spring fingers are employed to screen the bellows. The lack of accessibility in cryogenic systems can be a problem and asks for alternate solutions to eliminate possible overheating, sparking, etc that occurred in intensive beams. This note addresses an alternate kind of RF shield, which uses capacitive contact instead of mechanical contact. The analysis, as well as numerical example of a superconducting cavity structure, shows that the capacitive RF shield satisfies the impedance requirements of both beam and HOMs. The capability of thermal isolation is also analyzed
[en] Impedance of two vacuum chamber components, Bellows and BPM, is considered in some detail. In order to avoid generation of Higher-Order Modes (HOM's) in the NSLS-II bellows, we designed a new low-impedance RF shielding consisting of 6 wide and 2 narrow metal plates without opening slots between them. The short-range wakepotential has been optimized taking into account vertical offset of RF fingers from their nominal position. The results were compared with data of bellows designed at other laboratories. Narrow-band impedance of the BPM Button has been studied. TE-modes in the BPM button were suppressed by a factor of 8 by modification of existing housings. Two new types of housings are shown. The total impedance of the NSLS-II storage ring is discussed in terms of the loss factor and the vertical kick factor for a 3mm-Gaussian bunch.
[en] Skin and extremity dosimetry has been set up in order to avoid deterministic effects which might be observed following an important partial exposure. For all that, dose equivalent to skin and extremities have to be measured at the most exposed areas. For that purpose, both the most expose area has to be known and an appropriate dosimeter has to be placed there. It is all the more difficult because the source term is complex and the exposure conditions can vary. It is the case for the extremity dosimetry at MELOX facility. The variety of the working conditions leads to the fact that the most exposed extremity area is not the same for all the operators and can vary due to both workstation features and duration of intervention procedures. Due to these facts, to put a dosimeter at the right position is a matter of concern. The approach presented here consists in characterizing the exposure received by extremities, i.e. in 'mapping' the dose equivalents at the level of forearm and hand according to exposure conditions. Following the results obtained, the estimation of the maximum dose equivalent to extremities stemming from a measurement made at a precise point, becomes possible. (authors)
[en] The device presented in this paper is a sensor for monitoring pulse by measuring the bioimpedance of the thumb in an unobtrusive way. The sensor is based on magnetic induction measurement, a non-contact technique for measuring impedance changes of objects . The sensor head of the presented system has the form of a ring and is worn on the finger. The developed technique renders the possibility of easy and unnoticed pulse recording during every day activities without the need for, e.g. electrodes, a pulse belt around the chest, or a pulse photoplethysmographic finger or ear clip.
[en] A Piezoelectric thick-film sensor is a good candidate for the extraction of information from object slip in hand prosthesis. Five slip sensors were fabricated on different linkages of an artificial hand. The signals from each sensor were compared to the output from the sensor mounted on the fingertip. An analysis of the output signals from all the sensors indicates that the linkage sensors also produce similar output signals to the fingertip sensor. In the next phase of the research, velocity and acceleration of the slipped object will be considered in the analysis.
[en] Underactuated gripper has a broad application in the field of space robot and industrial robot because of its better shape-adaptation. However, because of the underactuated characteristics, it is a great challenge to accurately obtain the displacement of the contact point between the finger and grasped object, which makes it difficult to control the gripper grasp stably, especially the environmental parameters are unknown. This paper develops the identification of the unknown environmental parameters using a tactile array sensor based on the recursive leastsquares (RLS) method. The unknown environments are described as linear systems with unknown dynamics, and the environmental parameters are identified using the measured contact force and the derived displacement of the contact point which is obtained through the underactuated gripper dynamics. Meanwhile, an impedance adaptive control is presented to match the variability of the environment parameters, and the desired impedance model is imposed to the underactuated gripper to achieve stable grasp. A cost function that measures the contact force, velocity and displacement error is defined, and the critical impedance parameters are found to minimize it. At last, a co-simulation of ADAMS and MATLAB for an underactuated gripper grasp is implemented to show the feasibility of environmental parameters identification and its adaptive method.
[en] A long and slender finger can serve as a simple 'test bed' for different phase-ordering models. In this work, the globally conserved, interface-controlled dynamics of a long finger is investigated, analytically and numerically, in two dimensions. An important limit is considered when the finger dynamics is reducible to area-preserving motion by curvature. A free boundary problem for the finger shape is formulated. An asymptotic perturbation theory is developed that uses the finger aspect ratio as a small parameter. The leading-order approximation is a modification of the Mullins finger (a well-known analytic solution) whose width is allowed to slowly vary with time. This time dependence is described, in the leading order, by an exponential law with the characteristic time proportional to the (constant) finger area. The subleading terms of the asymptotic theory are also calculated. Finally, the finger dynamics is investigated numerically, employing the Ginzburg-Landau equation with a global conservation law. The theory is in very good agreement with the numerical solution
[en] To measure the radiation exposure to nuclear medicine personnel during synthesis and injection to the patients of 68Ga 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA)-1-Nal -octreotide (NOC)- (DOTA-NOC) using ring thermoluminescence dosimeters (TLDs). Synthesis of 68Ga DOTA-NOC was done on a semi-automated system. Finger doses were measured during synthesis and injection of 68Ga DOTA-NOC. The occupational workers wore TLDs at the base of ring finger of both hands. The finger doses of two radio chemists were measured during synthesis of 68Ga DOTA-NOC while that of a physician during its injection to the patients. Duration of the study was eight months and a total of 20 samples were prepared. During synthesis, the mean dose to base of left ring finger was 3.02 ± 1.01 mSv and to base of right ring finger was 1.96 ±0.86 mSv. Mean dose to base of left ring finger was 1.26 ± 0.35 mSv while that to base of right ring finger was 1.03 ± 0.13 mSv during injection. The mean dose was observed to be higher during synthesis than injection. However, the difference was not significant (P = 0.27 and P = 0.18, respectively). Overall mean finger dose of left hand was 2.43 ±1.21 mSv, whereas for the right hand the same was 1.65±0.82 mSv. Finger doses to radio chemists during semi-automated synthesis of 68Ga DOTA-NOC and that to the physician involved in injection of 68Ga DOTA-NOC were found to be within permissible limits. Ring dosimeters must be worn for the safety of the nuclear medicine personnel involved in synthesis and injection of 68Ga DOTA-NOC. (author)