Silicone Finger Research Articles

Silicone finger prosthesis using conventional method impression

Prosthetic fingers are a part of a medical art science community. Which means the fabrication of the prosthetic fingers is more of an art based treatment than a science. The prosthetic fingers must match with the missing part of the fingers or digits of the patient and even better if it can be used functionally. There are multiple causes of complete or partial fingers loss such as a disease or congenital malformation. But the most common are due to traumatic injuries. Despite the etiology, the effect of a loss finger has such an impact on the individual both functional and psychological. Therefore, prosthetic finger are one of the most popular approach to alleviate the problems instead with surgery approach. This case report describes a method of obtaining the use of prosthetic fingers functionally from the impression process and most importantly still have the aesthetic appearance with an easy and cheaper method by using silicone prosthesis.

Design modifications and evaluation of the silicone artificial finger joints.

There are many reasons that could lead to finger joint arthroplasty, and the most familiar reason is osteoarthritis. Silicone finger joint are the most commonly used implants. However, these implants might fracture with time and cause wear which will lead to chronic inflammation and synovitis for the patient and then implant failure. The aim of this study is to improve the design of the silicone finger joint and simulate the different designs using finite element analysis (FEA) simulation. Three different designs were drawn and FEA has been used in this study using Solidworks software. The first design is the silicone finger joint design without any modification, the second one is modified design with added ribs to the junction of distal stem and hinge and the third design was added filler material inside the body of the artificial joint. An axial force with 625N that was applied on the upper part of the distal stem which is nearly represents the maximum value of the grip strength for normal males. The results showed improvement on the design in which the concentrated stress at the junction of the distal stem and hinge of the design was distributed. In addition, the Von Mises stress was stable for the modified design with added ribs and the added filler material designs after 15°. The design modification could improve the stress distribution and stability of the artificial finger joint and increase the lifetime expectancy of these implants.

Kinematic Modeling of a Twisted-String Actuated Soft Robotic Finger as Part of an Anthropomorphic Gripper

Twisted string actuators (TSAs) generate high tendon-based (muscle-like) linear actuation and forces and have wide operational bandwidth. For these properties, TSAs are well-suited for advanced robotic and mechatronic applications, though their inclusion in soft robots has been limited. We recently employed TSAs to drive an anthropomorphic soft gripper which successfully demonstrated dexterous grasping and manipulation. While the gripper showed superior qualitative performance, the lack of modeling and control strategies limited its realization in a fully autonomous system that could generalize well to new grasping behaviors. As a first step toward this objective, this paper presents modeling strategies for a monolithic soft silicone finger driven by a TSA. A physics-based kinematic model is developed to predict the bending and velocity kinematics of the finger as a function of the TSA's twisting angle. An average error of 2.06° was obtained for the kinematic bending model across different actuation behaviors and an average error of 2.95°/s was measured for the angular velocity model.

Generating Clear Vibrotactile Cues with a Magnet Embedded in a Soft Finger Sheath.

Haptic displays act on the user's body to stimulate the sense of touch and enrich applications from gaming and computer-aided design to rehabilitation and remote surgery. However, when crafted from typical rigid robotic components, they tend to be heavy, bulky, and expensive, while sleeker designs often struggle to create clear haptic cues. This article introduces a lightweight wearable silicone finger sheath that can deliver salient and rich vibrotactile cues using electromagnetic actuation. We fabricate the sheath on a ferromagnetic mandrel with a process based on dip molding, a robust fabrication method that is rarely used in soft robotics but is suitable for commercial production. A miniature rare-earth magnet embedded within the silicone layers at the center of the finger pad is driven to vibrate by the application of alternating current to a nearby air-coil. Experiments are conducted to determine the amplitude of the magnetic force and the frequency response function for the displacement amplitude of the magnet perpendicular to the skin. In addition, high-fidelity finite element analyses of the finger wearing the device are performed to investigate the trends observed in the measurements. The experimental and simulated results show consistent dynamic behavior from 10 to 1000 Hz, with the displacement decreasing after about 300 Hz. These results match the detection threshold profile obtained in a psychophysical study performed by 17 users, where more current was needed only at the highest frequency. A cue identification experiment and a demonstration in virtual reality validate the feasibility of this approach to fingertip haptics.

Semi-occlusive management of fingertip injuries with finger caps: A randomized controlled trial in children and adults.

Background:Human fingertips can regenerate functionally and cosmetically excellent skin and soft tissues. Physiological conditions suppress scar formation and are thus a prerequisite for regenerative healing. Self-adhesive film dressings can provide such favorable conditions. The semi-occlusive treatment is superior to surgery. However, standard dressings leak malodorous wound fluid eventually until the wound is dry. Therefore, we developed and tested a silicone finger cap that forms a mechanically protected, wet chamber around the injury. Its puncturable reservoir allows access to the wound fluid for diagnostic and research purposes and the delivery of pro-regenerative drugs in the future.Methods:Patients >2 years with full-thickness fingertip injuries unsuitable for simple primary closure were randomized to start treatment with either the film dressing or the silicone finger cap. After 2 weeks, we changed to the other treatment. Patients’ choice on the preferred treatment after 4 weeks was the primary outcome parameter. Additionally, we monitored adverse events, unplanned visits, tissue gain, functionality, cosmetic outcome, and quality of life.Results:We randomized 11 patients 2 to 72 years to each group. Eighteen to 20 (90%, intention-to-treat) patients preferred the finger cap. All patients were satisfied with the cosmetic outcome, 88.9% had no disturbing sensibility changes, and 73.7% could report no distortion in the finger’s daily use. Epithelialization took between 5 weeks for Allen II and up to 9 weeks in Allen IV injuries. There were 19 device-related adverse events under film dressing and 13 under the finger cap. There were neither severe adverse device effects nor unexpected severe adverse device effects.Conclusion:Employing the summative or synthetic primary endpoint "patient decision for one or the other procedure," our pseudocross-over-designed RCT succeeded in statistically significantly demonstrating the superiority of the silicone finger cap over conventional film therapy. The finger cap was safe and effective, reaching excellent results on all treated injuries without any need for disinfection, antibiotics, shortening of protruding bones, or treatment of hypergranulations. Distal to the tendon insertions, we did not see any limitations regarding injury mechanism, amputation plane, or patients' age.

Impact of Silicone Finger Prosthesis in Activities of Daily Living and Passive Function in Proximal Phalanx Index Finger Amputation

The index finger plays a major role in hand function. Subjects who sustain traumatic amputation of the single index finger also suffer both psychological and functional loss. Most of previous studies primarily focused on psychological benefits with finger prosthesis; however, it is essential to identify the functional benefit of the silicone finger in respective activity spectrum. To determine the improvement in function and activities with silicone finger prosthesis in proximal phalanx index finger amputation. Sixteen subjects were evaluated for the grip strength, pinch strength, and activities with dynamometer position II, pinchometer, and DASH questionnaire, respectively. Significant improvement of grip strength revealed in dynamometer position II ( p = 0.041) when tested without and with silicone finger prosthesis. The overall abilities in activities of daily living were improved significantly ( p = 0.005) as assessed by disability of arm, shoulder and hand questionnaire. Large effect sizes were noted in some activities like writing, jar opening, and carrying heavy object. Silicone finger prosthesis provides a functional benefit to the subjects in multiple activities. Partial loss of a finger has a relationship in limitation of hand function. Generally, clinicians prescribe silicone prosthesis for rehabilitation of finger amputee to restore the cosmetic purpose; however, functionality of the finger is also required to be restored. This study describes the role of silicone finger prosthesis on function and different activities for the subjects suffering from the index finger proximal phalanx amputation. Nayak S, Lenka PK, Equebal A, et al. Impact of Silicone Finger Prosthesis in Activities of Daily Living and Passive Function in Proximal Phalanx Index Finger Amputation. Indian J Phys Med Rehab 2019;30(3):59–65.

A simplified silicone finger prosthesis: A clinical report

Psychological impact gives more affects to the patient's desire to make a finger prosthesis. Retention is an important factor in the fabrication of finger prostheses. a fairly simple way is to use the vacuum effect which can be obtained from modifying the stone model of the finger. The present article uses a technique to get retention from passive vacuum fit. This method can be used to fabricate finger prostheses with simple materials and will reduce costs.

A simplified silicone finger prosthesis: A clinical report

A simplified silicone finger prosthesis: A clinical report

3D-printed nails for aesthetic silicone prostheses.

The nail is a crucially important part that needs to be closely reproduced in aesthetic silicone prostheses. The traditional method of producing prosthetic nails is a laborious process often fraught with errors and rejects. In this article, additive manufacturing or 3D printing intervention was sought to make this process less time-consuming and more exacting. With a focus on finger prosthesis, the process involves reverse engineering a patient's hand using a 3D scanner to obtain a digital blue print for referencing. 3D models of the nail shapes were created using CAD software. Colors sampling is obtained using image processing software from 2D digital images. Using specifically the inkjet technology from Stratasys, batches of nails of different sizes and colors were printed, which were then used for manual adhesion to silicone finger prostheses. This article has demonstrated that 3D printing is able to produce nails of comparable quality with those produced by traditional methods in size, shape, curvature, and thickness. More consistent thickness, better size, and shape-matching using 3D files also minimize rejects and grinding time when finishing a prosthesis, leading to significant time savings. However, 3D-printed nails fall short in color match, surface texture, and life-likeness. Traditionally produced nails that are made using a more translucent grade of acrylic than that used in the 3D-printed nails are better able to reproduce the life-like coloration of the translucent human nail. The limitations encountered with 3D printing as applied to prosthetic nails production relate to camera settings, digital image color capture and display, differences in color system used in the printer and monitor, ambient lighting, and suitability of acrylic grade used with the proprietary 3D printing system for material translucency or opacity.

Amputation to rehabilitation’ - silicone finger prosthesis: A case report

In patients where surgical reconstruction of amputated finger is not possible, a finger prosthesis provides psychological, functional and esthetic rehabilitation. The success of the prosthesis depends on the meticulous planning, precise impression procedures, designing of prosthesis and selection of appropriate materials. This clinical report presents a case of rehabilitation of a patient with three amputated fingers due to trauma by the chaff machine. The amputation was at different digit levels. The patient was successfully rehabilitated with a custom made silicone finger prosthesis fabricated from room temperature vulcanizing (RTV) silicone utilizing anatomical and mechanical modes of retention.

A Technique to Improve Outcome of Silicone Finger Prosthesis

A Technique to Improve Outcome of Silicone Finger Prosthesis

Custom-made silicone finger prosthesis: A case report

Restoring the digit with a esthetic prosthesis with passive function will enhance patients’ acceptance and confidence. A 23-year-old female patient reported to the Department of Prosthodontics, Regional Dental College, Guwahti, Assam, India, with a chief complaint of a partially missing index finger on her left hand. She wanted to get it replaced because she was getting engaged. The prosthesis was inserted, and a wide silver ring over the margin of the finger prosthesis was placed at the mid part of middle phalanx to disguise the junction line. The patient expressed high satisfaction with the end result and the retention of the prosthesis.

Fabrication of a hollow finger prosthesis using a three- piece mould technique: A case report

Amputation of finger causes physical, psychological and economical harm to the patient. Restoration of the amputated part with a prosthesis made of silicone material can give a life like feel and protect the patient from social stigma. This case report describes a technique to fabricate a hollow finger prosthesis using Die-pin system. Hollow silicone finger prosthesis proved to be more comfortable and satisfying to the patient.

The Prosthetic Rehabilitation of a partially amputated finger using a silicon prosthesis: A case report

Abstract :
 Loss always has a negative impact on an individual which engraves a feeling of incompleteness in many. Loss of anybody part creates an obstruction in the normal functioning of the body. Mostly the appendages such as arms, fingers, etc have a very important role in routine life which can restrict the living psychologically, functionally, and socially. The goal in rehabilitating a body part should be to create a substitute that is indistinguishable from adjacent and contralateral counterparts. Therefore maxillofacial prosthodontics is not only science but also an art. The present article is a case report of a person with a missing finger briefing the fabrication methodology of a custom-made silicone finger prosthesis.

Use of silicone finger prostheses in amputee patients: An integrative review.

This study aimed to perform an integrative review of the literature on the use of silicone finger prostheses in amputee patients. Searches were performed in the PubMed, EMBASE, Web of Science, Scielo, and Cochrane Library databases until July 2021. Descriptors used in this article were: Silicone, finger, rehabilitation, and prosthesis. Clinical research and clinical reports on silicone finger prostheses, available in full and in English were included. Initially, 152 articles were identified. After establishing the inclusion/exclusion criteria, 23 studies were identified and constituted the final sample. Regarding the publication date of the included studies, 17.2% of them were published between 2012 and 2016. Most of the rehabilitations occurred in India (69.9%; n = 16), and the mean age of patients who used prostheses was 38.1 years. The level of scientific evidence of the included studies was IV and VI. Therefore, patients rehabilitated with silicone finger prostheses highlighted significant improvements in functional range of motion, restoration of self-esteem, advantages in psychological therapy, more pleasant social interaction, and changes in their quality of life.

Prosthetic Rehabilitation of Patient with Mixed Connective Tissue Disease Using Glove Type Silicone Finger and Toe Prosthesis

The hand is a powerful tool and its loss causes a severe psychological and physical drawback. A considerable number of people each year suffer finger or partial finger amputations as a result of malignant disease, trauma, and congenital deformity.Prosthetic restoration is usually considered difficult for the whole or a part of the finger and it worsens if multiple fingers are involved. Additionally in patients with mixed connective tissue disorders with overlapping clinical features of scleroderma and arthritis any undue pressure from the artificial rings or vacuum fit of the prosthesis might cause further vasoconstriction that could worsen blood flow to extremities. This clinical report describes a simple and economical method for prosthetic rehabilitation of a patient with mixed connective tissue disease following digital loss using a custom made prosthesis with medical grade tissue adhesive as retentive aid.

Prosthetic rehabilitation of patient with mixed connective tissue disease using glove type silicone finger and toe prosthesis

Prosthetic rehabilitation of patient with mixed connective tissue disease using glove type silicone finger and toe prosthesis

Custom-Soldered, Double-Ring Retained Silicone Finger Prosthesis

ABSTRACT Introduction Accomplishment of adequate retention in prosthesis is vital to patient comfort. The purpose of this article is to present a technique of fabrication of a nonimplant, nonadhesive retained silicone finger prosthesis for a short, flabby residual digit. Materials and Methods To achieve adequate retention in this compromised clinical scenario, two rings were used: one on the residual finger and the other on the adjacent finger, which were soldered at accurate orientation using a custom-made putty index. Results Retention of the prosthesis was found to be satisfactory and alleviated the apprehension of the patient regarding surgical placement of implants. Conclusions The technique described in this report provides an effective, reversible, and straightforward method of managing the compromised situation. The double-ring technique offers a nonsurgical alternative to rehabilitation of patients with compromised residual digits.

Conservative treatment of fingertip injuries in children - first experiences with a novel silicone finger cap that enables woundfluid analysis.

Introduction: Human fingertips are able to regenerate soft tissue and skin after amputation injuries with excellent cosmetic and functional results when treated with semiocclusive dressings. Despite bacterial colonizations, proceeding infections are not reported with this management. The underlying mechanisms for this form of regenerative healing as well as for the resilience to infections are not known. Due to the lack of mechanical protection, the leakage of maloderous woundfluid and the sometimes challenging application, conventional film dressings have their problems, especially in treating young children. We therefore treated selected patients with a novel silicone finger cap with an integrated wound fluid reservoir that enables atraumatic routine wound fluid aspiration.Methods: We report on 34 patients in between 1 and 13 years with traumatic fingertip amputations primarily treated with occlusive dressings. 12 patients were treated with a novel silicone finger cap. We summarized clinical data for each patient. This included photographs and microbiological results from wound fluid analyses, whenever available. Results: The results of both, conventional film dressing and silicone finger cap treatment, were excellent with no hypersensitivity and no restrictions in sensibility and motility. Even larger pulp defects were rearranged in a round shape and good soft tissue coverage of the distal phalanx was achieved. Nail deformities were not observed. We detected a wide spectrum of both aerobic and anaerobic bacteria in the wound fluids but infections were not observed. Epithelialization times did not differ significantly and no severe complications were seen in all primarily conservatively treated patients. Conclusion: This study provides preliminary data demonstrating that the treatment with the silicone finger cap leads to excellent clinical results in wound healing. Interestingly, the wounds were colonized with a wide range of bacteria including species that may cause wound infections. However, we saw no proceeding inflammation and the regeneration was undisturbed. In the future, the efficacy of this new management should be evaluated in randomized, controlled clinical trials to confirm the results under standard conditions and get more insight into the role of the wound microbiome as well as other factors that may promote regeneration. The aspirable Reservoir of the finger cap will enable easy atraumatic sampling of wound fluids both for diagnostic and for research purposes as well as possibly allowing direct administration of pro-regenerative drugs in the future.

Adjustment to finger amputation and silicone finger prosthesis use

Purpose: Finger amputations are the most common amputations of upper limbs. They influence hand function, general functioning and quality of life. One of the possibilities for rehabilitation after finger amputation is fitting a silicone finger prosthesis. We wanted to evaluate the adjustment to amputation and prosthesis use in patients after finger amputation.Methods: We included 42 patients with partial or complete single or multiple finger amputation of one hand who visited the outpatient clinic for prosthetics and orthotics at our institute and received a silicone prosthesis. We assessed their adjustment to amputation and prosthesis with the Trinity Amputation and Prosthesis Experience Scales (TAPES).Results: Most of the patients (28, 67%) had a single finger amputated. The average scores on all TAPES subscales (except adjustment to limitation) were above 50% of the maximum possible score. On average, the scores were the highest on the general adjustment and satisfaction with the prosthesis subscales.Conclusions: Silicone prostheses for finger amputation of upper limb play an important role in the process of adaptation to amputation. They offer aesthetically satisfying results and alleviate social interactions, which influences overall quality of life.Implications for RehabilitationSilicone prostheses for finger amputation of upper limb offer an aesthetically satisfying result and alleviate problems with social interactions.Their influence on hand function is not optimal, but the prosthesis improves the amputee's quality of life.