Finger Research Articles

Automated Digital Wind Instrument using Arduino UNO Microcontroller

Recently, Blackstar Amplification Ltd. has introduced a Compact Carry-On Digital Wind Instrument (CDWI), mirroring the design of traditional recorder instruments in their size and shape. This CDWI can be played as a traditional wind instrument by blowing into the mouthpiece and simultaneously manipulating finger holes, enabling the production of desired musical notes. The main aim of this research work is the development of a prototype model to automate the CDWI, by utilizing the Arduino UNO microcontroller board and introducing the Automated Digital Wind Instrument (ADWI). The CDWI has a mouthpiece, nine finger holes, and one thumb hole, and the blowing mechanism can be automated by using a 12 Volts DC air blower and a servo valve. The author ingeniously develops a new servo valve using a plastic syringe, a ball, and a 5 Volts DC micro servo motor to regulate the air pressure blown into the mouthpiece. The ADWI fingers are meticulously crafted using plastic pen barrels, thrust tubes, and metallic springs to simulate the actions of a human music player's fingers. Positioned to maintain all finger holes in an open state by default, the selective closing of specific holes is achieved by ten micro servo motors to produce a specific musical note. In a preliminary test, the ADWI prototype is programmed to perform the Nursery Rhyme "Twinkle, Twinkle, Little Star." While evaluating the sound output by hearing, it is evident that the proposed ADWI effectively generates all the necessary musical notes. However, the noise generated by the air blower and micro servo motors introduces interference, impacting the clarity of the produced musical notes. Consequently, it is planned to integrate a noise reduction mechanism as part of future work.

Contact‐Based and Proximally Thermosensitive Few‐Layer Graphene Ntc Thermistors with Highly Fast Switching Behavior

AbstractPatterning graphene onto polymeric materials offers benefits in realizing flexible, stretchable, and wearable multifunctional electrodes. However, the employed integration approaches and use of non‐patternable polymers hinder the patterning of graphene at the sub‐millimeter (mm) scale. Serpentine‐shaped thermally active graphene patterns (thermistors) of 500 × 500 µm2 area are reported by the seamless integration of chemical vapor‐deposited graphene (GCVD) into readily available SU‐8 polymer with MEMS‐compatible cleanroom fabrication processes. The thermistor resistance decreases with an increase in graphene temperature changed by local heat conduction or environmental thermal radiations; hence, exhibits a negative temperature coefficient (NTC) of resistance of 0.0012/°C. Furthermore, very fast resistive switching with 1 s response and 3.2 s recovery time is observed under cyclic heating and cooling. Several application scenarios including, monitoring of surface temperature (e.g., kettle and human body), rapid response (0.25 s) to heat conduction and radiations (0.5 s) from human finger at room temperature for contact and touch‐free proximity switching (e.g., turn ON and OFF an LCD display) are demonstrated. Moreover, owing to its small area less than a ceramic resistor enabled to integrate the fabricated thermistor onto a printed circuit board (PCB) to construct a fully packaged thermometer to monitor ambient temperature.

Friction Behavior of Fingers on Micro-Textured Flexible Surfaces

Abstract Compared to rigid materials, people have a distinct tactile perception when touching flexible materials. Moreover, adding micro-patterns to the surface enhances the tactile experience even further. This sensation arises from the physical stimulation of frictional behavior between the skin and flexible materials. Therefore, this study focuses on human fingers as the research subjects and employs flexible materials with micro-textured surfaces as frictional objects. A friction test setup is designed to conduct a series of finger friction experiments, and theoretical explanations are provided to elucidate the reasons for performance variations. Research findings show that as the normal load increases, the frictional force gradually increases while the friction coefficient decreases. The former is attributed to the expanding contact area, while the latter is due to the inconsistent rate of frictional force increment with the normal load. The impact of friction velocity is mainly caused by changes in the viscous forces generated at the liquid film in the contact interface and the energy loss in elastic hysteresis. On the other hand, the effect of surface micro-topography is primarily a result of the transition between partial contact and full contact modes under the influence of normal load, leading to alterations in the contact area. Overall, during the finger friction process on a flexible micro-textured surface, changes in contact area play a vital role in modifying frictional performance, with adhesive friction exerting a more significant influence than deformation friction. This study summarizes the variations in frictional performance parameters based on experiments and analyzes the effects of contact area changes and deformation friction mechanisms from a theoretical perspective, providing a theoretical foundation for exploring the genesis of delicate tactile sensations during friction.

Haptic device and interface to reproduce force and tactile feedback of biological tissues

Haptic information of biological tissues is important in applications and research in medical fields, including force and tactile feedback. Due to resource limitation, various biological tissues may not be easily accessible, so as to hinder their haptic research and development. Therefore, in this paper, force and tactile feedback of five pig tissue samples are respectively reproduced by using a combination of haptic device and interface. Specifically, the haptic device is used to reproduce the force-displacement relationship, while the haptic interface is used to provide various and controllable touch sensations to human fingers. First, the force-displacement relationships of five pig tissue samples are derived via compression tests. Second, the haptic device with two springs and a customized raceway is designed, modeled, and fabricated. Third, compression tests are performed on the haptic device to verify its reproduction accuracy. Later, the pneumatic haptic interface is designed and fabricated. Last, the haptic device and interface are combined and tested. The proposed haptic device and interface can provide accurate force feedback as well as various and controllable tactile feedback to human fingers.

A palmitoyl transferase chemical–genetic system to map ZDHHC-specific S-acylation

The 23 human zinc finger Asp-His-His-Cys motif-containing (ZDHHC) S-acyltransferases catalyze long-chain S-acylation at cysteine residues across an extensive network of hundreds of proteins important for normal physiology or dysregulated in disease. Here we present a technology to directly map the protein substrates of a specific ZDHHC at the whole-proteome level, in intact cells. Structure-guided engineering of paired ZDHHC ‘hole’ mutants and ‘bumped’ chemically tagged fatty acid probes enabled probe transfer to specific protein substrates with excellent selectivity over wild-type ZDHHCs. Chemical–genetic systems were exemplified for five human ZDHHCs (3, 7, 11, 15 and 20) and applied to generate de novo ZDHHC substrate profiles, identifying >300 substrates and S-acylation sites for new functionally diverse proteins across multiple cell lines. We expect that this platform will elucidate S-acylation biology for a wide range of models and organisms.

Enhanced braille recognition based on piezoresistive and piezoelectric dual-mode tactile sensors

Human Tactile perception can be divided into pressure perception and slip perception according to the mode of contact. At present, however, tactile sensors can not have the same good performance as human pressure and slip perception. In this paper, a piezoresistive and piezoelectric dual-mode tactile sensing scheme is proposed based on human finger tactile skin structure. PVDF polymer is used as the sensitive material in piezoelectric layer, which has good dynamic response and high sensitivity. Graphene and carbon black are used as the sensitive material in piezoresistive layer, the array process is simple and high resolution can be achieved. The fast response of piezoelectric signal can be used to segment the piezoresistive signal and improve the recognition accuracy when the tactile sensor is used for slip sensing. At the same time, the piezoelectric layer can also reflect the velocity information and direction information. In recognition method, according to the feature that the continuous tactile signal has both temporal and spatial features in the process of sliding, CNN-LSTM is proposed in this paper. The tactile sensors is integrated into the robot arm to detect 20 kinds of braille. At the same speed and the same force, the recognition rate of bimodal braille recognition is 90.58%. In addition, the model can be well recognized at different speeds and sliding directions, and the recognition rate is 84.2%. Finally, the tactile sensor is wore on the index finger of human hand, the average recognition rate of touch braille is 77.5%, which shows that the algorithm has good robustness, and the speed of recognition is twice as fast as that of the normal blind. In the future, it can be applied to blind reading, surface detection, texture identification and other fields.

Convolutional sparse coding for compressed sensing photoacoustic CT reconstruction with partially known support.

In photoacoustic tomography (PAT), imaging speed is an essential metric that is restricted by the pulse laser repetition rate and the number of channels on the data acquisition card (DAQ). Reconstructing the initial sound pressure distribution with fewer elements can significantly reduce hardware costs and back-end acquisition pressure. However, undersampling will result in artefacts in the photoacoustic image, degrading its quality. Dictionary learning (DL) has been utilised for various image reconstruction techniques, but they disregard the uniformity of pixels in overlapping blocks. Therefore, we propose a compressive sensing (CS) reconstruction algorithm for circular array PAT based on gradient domain convolutional sparse coding (CSCGR). A small number of non-zero signal positions in the sparsely encoded feature map are used as partially known support (PKS) in the reconstruction procedure. The CS-CSCGR-PKS-based reconstruction algorithm can use fewer ultrasound transducers for signal acquisition while maintaining image fidelity. We demonstrated the effectiveness of this algorithm in sparse imaging through imaging experiments on the mouse torso, brain, and human fingers. Reducing the number of array elements while ensuring imaging quality effectively reduces equipment hardware costs and improves imaging speed.

Soft Wearable Body-Powered Hydraulic Actuation System for a Prosthetic Finger Design.

Finger and fingertip loss is the most common form of upper-limb amputation. With a focus on amputations involving the loss of distal and/or partial middle finger segments, this paper outlines the design and development of a novel soft body-powered hydraulically-driven actuation system for a prosthetic finger, while offering an in-depth examination of its subsystems. The proposed device utilises a soft wearable hydraulic mechanism to transfer pressure from the proximal interphalangeal (PIP) joint of the human finger to the distal interphalangeal (DIP) joint of the prosthetic finger, enabling movement of the soft prosthetic DIP joint. The design parameters of the soft actuator, such as its configuration, constituent material, and volume were analysed through experiments with able-bodied participants. Each participant tried 42 different actuators while flexing their index finger, repeating the task four times, yielding 168 trials per participant. The human and prosthetic finger flexion angles and resultant pressures were measured using an Aurora electromagnetic sensor and a fluid pressure transducer. All data was segmented and analysed. Soft actuator designs were selected through statistical analysis of the material (Agilus 30 and Dragon Skin 30), configuration (chambers located underside or around the PIP joint), and volume. The study demonstrated that the selected soft wearable hydraulic mechanism transferred generated pressure from the participant's PIP joint effectively, enabling movement of the prosthetic digit. Our research contributes to current developments in versatile body-powered prosthetic devices, laying the foundations for broad applications in affordable healthcare devices.

Formulation of motion between human finger and machine considering non-smooth and soft contact phenomena

Formulation of motion between human finger and machine considering non-smooth and soft contact phenomena

Rapid-response humidity sensors based on ultra-thin films stacked with single-layer graphene oxide

Monitoring and control of humidity is important for industry, agriculture and human activities. Currently, it is achallengeto develop highly sensitive humidity sensors with both the response time and recovery time less than 1 s.Therefore, it isdifficult to dynamically monitor rapid changes in humidity. Here, we report a resistive humidity sensor based on an ultrathin graphene oxide (GO) film, which is formed by stacked single-layered GO. Both the response and recovery time of the sensor is less than 1 s in the range of 10 %–95 % relative humidity (RH). The shortest response and recovery time of the reported GO-based resistive humidity sensor can be 0.33 s at 10 % RH, indicating the fastest response and recovery property to date. Moreover, the sensor is sensitive, and it can accurately detect the distance between the sensor and the human finger as well as the strength of the human breath. The simple preparation, microscale structure, and extremely fast response make the GO-based sensor a new alternative for integrated humidity sensors with real-time monitoring functions.

Halide-dependent humidity sensing of Cs2SnX6 (X = Cl, Br, I) perovskites for real-time human physiological moisture detection

Lead-free halide perovskites Cs2SnX6 (X = Cl, Br, I) exhibit favorable humidity sensing with a response sequence of Cs2SnCl6 > Cs2SnBr6 > Cs2SnI6, enabling great potential for real-time non-contact human breath and finger monitoring.

Research on the grasping characteristics of composite-driven double-finger flexible manipulator.

Aiming at the flexible manipulator grasping complex target parts of different shapes, a double-finger flexible manipulator model is proposed. The manipulator is composed of a flexible mechanical finger, a driving component and a position compensation mechanism. It imitates the motion characteristics of human finger joints and follows the principle of double-fingered grasping. According to the structural characteristics of the target contour, the grasping features of the target contour are extracted. Through the motion principle of the flexible manipulator, the kinematic model of the envelope clamping process of the manipulator target is carried out. Finally, the flexible manipulator experimental platform is built to verify the grasping characteristics of the flexible manipulator target. The results show that the manipulator can realize the adaptive grasping of cylinder and cuboid parts, which have high grasping reliability and stability.

Electrochemically triggered rational design of bismuth copper sulfide for wearable all-sulfide semi-solid-state supercapacitor with a wide operational potential window (1.8 V) and ultra-long life

Gel electrolyte-based wearable all-sulfide semi-solid-state supercapacitor (ASSSC) device with ∼100% capacitance retention across the 40 000 charge–discharge cycles. The ASSSC devices are attached to human fingers to power electronic gadgets.

DESIGN OF A NEW MINIATURE CIRCULAR BIOSENSOR FOR DETECTING GLUCOSE CONCENTRATION IN BLOOD

The research introduces a new small slotted circular biosensor for non-invasively measuring blood glucose levels. The proposed biosensor has an operating frequency of 5.15 GHz. Its overall dimensions are 27 mm × 23 mm × 1.6 mm, with a radius of 8 mm. It uses electromagnetic principles to detect changes in glucose levels without intrusive treatments. Using a cost-effective FR4 dielectric substrate, the biosensor simulates human finger tissue to accurately depict changes in glucose concentration. The results showed that the proposed biosensor can detect changes in glucose concentration by electromagnetic modeling, making it a potential option for continuous glucose monitoring in clinical settings.

Management of Finger Tip Injuries - Our Experience at Tertiary Care Institute

Management of Finger Tip Injuries - Our Experience at Tertiary Care Institute

Analisis Ergonomika Bagian Penghancur pada Mesin Pencacah Pakan Ternak Multiguna

The agricultural machinery use can increase time and labor efficiency compared to traditional agricultural systems. One of the agricultural machines that is widely used in the livestock sector is the multi-purpose animal feed chopper machine. This machine has two parts with different functions. The chopper section is used to chop long-shaped animal feed, the crusher section is used to crush short-shaped animal feed, for example corn cobs. Machines can work optimally if the design considers ergonomic principles so that they can be operated safely and comfortably. Operating the machine safely and comfortably for the operator can increase the productivity of machine performance. This research goal was to analyze the ergonomics of multi-purpose animal feed chopping machines in the crushing section. The research used quantitative methods supported by literature studies. The research parameters consisted of Standing Finger Tip Height (TJUB), Standing Vertical Reach (JVB), Standing Horizontal Reach (JHB), recommended load limit data (RWL), work fatigue level, equipment noise, environmental temperature, and body posture measurements using REBA method. The research results stated that the crushing input on the multipurpose animal feed chopper machine was classified as ergonomic with an input height of 140 cm, between P95 TUJB (68.8 cm) and P5 JVB (183.5 cm). Machine operation did not cause fatigue with a CVL value ≤ 30%, RWL value 5.55 kg, Noise level 98.91 dBA. The environmental temperature suitable for operating the machine in the morning was (29.1oC) and in the afternoon was (28.6 oC). The operator's body posture measurement using REBA was at a moderate level (score 5). It is recommended modifying the machine design to improve the safety and comfortness of the operator when operating the crushing part. Keywords: Anthropometry, CVL, Physical Environment, REBA, RWL

MENGUNGKAP PERISTIWA KEMATIAN KRIMINAL KASUS PEMBEKAPAN PERSPEKTIF MEDIKOLEGAL

Death is a definite thing in life that can be identified clinically in a person through observing the changes that occur in the corpse's body. The mechanism of death can be unnatural. In this case, wounds were found in the mouth, a form of mechanical smothering. Smothering can cause death, so it is an important reason to discuss and aims to reveal unnatural injuries and what events occurred. The examination method uses the principles of evidence based medicine. On external examination, bruises were found on the inner lips, both eyes (racoon eyes), left cheek, upper jaw, lower jaw, abrasions on the lips with teeth prints, and cheeks and several other bodies injuries. The lips, the tips of both fingers and the tips of the toes were bluish in color and bleeding spots were found on both inner eyelids. The conclusion of the external examination of the corpse showed that the wounds were unnatural and there were signs of strong pressure on the mouth and nose area which could cause suffocation and there were signs of cranial base trauma. These wounds were caused by blunt trauma Key words: Asphyxia, Cranial Base Fracture, smothering

Optimization of Graphene infused Natural Rubber Sensing Film and Polydimethylsiloxane for Flexible Pressure Sensor

A flexible and stretchable pressure sensor offers significant benefits in human-computer interaction, healthcare, and tactile sensing in robots. We present a novel study optimising Polydimethylsiloxane (PDMS) and graphene-infused unvulcanised natural rubber sensing film to increase sensor sensitivity and dielectric permittivity. By optimising the PDMS thickness uniformity, NR-G film’s impedance and capacitance-pressure loading response, it is possible to enhance the pressure sensor's sensitivity across a wide pressure range, covering human finger motion. With our synthesized homogenous 5wt% of NRG composite, a capacitance value of 193pF was achieved when applying pressure of 150 kPa at a frequency of 0.5 Hz. Excellent sensitivity and dielectric permittivity of 0.020 kPa-1 and 109.1, respectively, which is ~ 6.5 folds higher than pure NR. PDMS thickness of 300μm with ±3% uniformity was achieved using 90s spin time and 200rpm spin speed. This optimisation of sensing material and substrate is important in developing wearable sensors having applications in soft robotics, health monitoring electronics, and soft human-machine interfaces.

Parameter estimation of a model describing the human fingers.

The goal of this paper is twofold: firstly, to provide a novel mathematical model that describes the kinematic chain of motion of the human fingers based on Lagrangian mechanics with four degrees of freedom and secondly, to estimate the model parameters using data from able-bodied individuals. In the literature there are a variety of mathematical models that have been developed to describe the motion of the human finger. These models offer little to no information on the underlying mechanisms or corresponding equations of motion. Furthermore, these models do not provide information as to how they scale with different anthropometries. The data used here is generated using an experimental procedure that considers the free response motion of each finger segment with data captured via a motion capture system. The angular data collected are then filtered and fitted to a linear second-order differential approximation of the equations of motion. The results of the study show that the free response motion of the segments is underdamped across flexion/extension and ad/abduction.

Highly sensitive skin-like wearable optical sensor for human physiological signals monitoring

Pusle signal is an important information related to the cardiovascular system. Long-term and accurate pulse monitoring is of great significance. Wearable fiber-optic sensors show great promise in this field. In this work, a highly sensitive wearable skin-like optical pressure sensor for human physiological signals monitoring is demonstrated by embedding bent fiber in a silica gel film. By employing small-core fiber (SCF) and fabric, the skin-like optical pressure sensor achieves high sensitivity (2.2 kPa−1), fast response (5 ms), low detection limit (4 Pa) and remarkable stability (over 40,000 cycles). As a proof of concept, monitoring of pulse from the most parts of human body and finger motion have been demonstrated based on the proposed sensor through the power variation of the output light. Moreover, abnormal pulse signals in unhealthy states are demonstrated. This novel photonics-based sensor provides a new basis for developing high-performance wearable medical devices.