• Title/Summary/Keyword: soft fingertip

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Determination of optimal contact forces for multi-fingered robotic hands (다지 다관절 로봇 손의 최적 접촉력 결정 방법)

  • 백주현;서일홍;최동훈
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10a
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    • pp.52-56
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    • 1990
  • An algorithm is proposed to determine the optimal contact forces of robotic hands, where the soft finger contact as well as the frictional point contact are considered. Especially, the algorithm can be efficiently applied to the case of multi-point contact by inner-link as well as fingertip. To show the validities of the algorithm, several numerical exampies are presented by employing a robotics hand with three fingers each of which has four joints.

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Correction of Hook Nail Deformity with Composite Graft (복합조직이식을 이용한 갈고리 손톱 변형 교정의 임상례)

  • Son, Dae Gu;Sohn, Hyung Bin;Kim, Hyun Ji
    • Archives of Plastic Surgery
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    • v.34 no.3
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    • pp.377-382
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    • 2007
  • Purpose: Hook nail deformity is caused by inadequately supported nail bed due to loss of distal phalanx or lack of soft tissue, resulting in a claw-like nail form. A composite graft from the foot bencath the nail bed gives adequate restoration of tip pulp. Methods: From September of 1999 to March of 2004, six patients were treated for hook nail deformity and monitored for long term follow up. Donor sites were the lateral side of the big toe or instep area of the foot. We examined cosmetic appearance and nail hooking and sensory test. The curved nail was measured by the picture of before and after surgery. Results: In all cases, composite grafts were well taken, and hook nail deformities were corrected. The curved nail of the 4 patients after surgery were improved to average $28.7^{\circ}$ from average $55.2^{\circ}$ before surgery. The static two point discrimination average was 6.5mm and the moving two point discrimination average was 5.8mm in the sensory test. Conclusion: Composite graft taken from foot supports the nail bed with the tissue closely resembling the fingertip tissue, making it possible for anatomical and histological rebuilding of fingertip.

Reconstruction of the Soft Tissue Defect of the Finger Using Digital Island Flap with Supercharged Vein (손가락섬피판으로 손가락 연조직 재건시 과급정맥문합)

  • Choi, Hwan Jun;Kim, Nam Joong;Choi, Chang Yong
    • Archives of Plastic Surgery
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    • v.36 no.2
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    • pp.153-160
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    • 2009
  • Purpose: The heterodigital or homodigital artery island flap is a popular method of reconstruction for finger defects. Sometimes, digital artery island flap has some disadvantages such as postoperative flap edema, congestion, and partial necrosis of the flap margin. However, we could decrease these disadvantages by means of venous superdrainage. The aim of this study is to report usefulness and postoperative results of venous supercharging digital artery island flaps for finger reconstruction. Methods: From March of 2005 to March of 2008, a total of eight patients with soft tissue defects of the finger underwent venous supercharging digital island flap transfer. Briefly, the flap is harvested along with dorsal vein that is then anastomosed to a recipient vein in an end - to - end fashion, after flap transfer and insetting. Using this technique, eight patients were operated on, ranging in age 23 to 52 years. Results: All the flaps survived with a success rate of 100 percent, thus fully satisfying the reconstructive requirements. No postoperative flap congestion was recognized, obviating the need to take any measures for venous engorgement, such as suture removal. Among 8 cases, it was possible to make an long - term and follow - up observation more than 6 months. In these cases, the fact that light touches and temperature sensations can be detected in all the flaps. Cold intolerance and hyperesthesia were not seen in our series. Conclusion: Providing good harmony with conventional methods and microsurgery, inclusion of a vein with the heterodigital and homodigital artery island flap allows a more reliable and safer reconstructive choice for finger defects. The venous supercharged island flap is a reliable flap with a consistent arterial structure, and with its augmented venous drainage, it is more reliable, providing single - stage reconstruction of adjacent finger defects, including the fingertip.

A Tactilely Transparent Soft Glove with High Grasping Force (높은 파지력을 가지며 촉감을 전달할 수 있는 유연한 글러브)

  • Jeong, Yong-Jun;Kim, Jong-In;Jeon, Hyeong-Seok;Lee, Deok-Won;Kim, Yong-Jae
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.12
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    • pp.1011-1020
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    • 2016
  • This paper introduces a tactilely transparent soft glove composed of soft materials and flexible structures. Although it is hard to achieve a high grasping force with conventional grip-assist gloves made from soft material, the proposed glove can exert a high force by using a novel structure. This structure has a triangular shape composed of flexible structural frames, soft fabric, and belts. It can produce grip-assist moment compliantly without harmful force or misalignment with the human fingers. The whole finger part that comes into contact with objects is made of thin and soft fabric in order to facilitate sensation transference. The proposed tactilely transparent soft glove enables the user to manipulate various objects owing to both the softness and high grasping force; it helps lifting heavy weight objects as well as permitting delicate tactile feeling on the palm and fingers. The proposed concept was applied to a two-finger grip-assist device for validation. In addition, the experimental results regarding grasping objects, fingertip force, and grasping force are presented.

Hand Resurfacing with Full Thickness Skin Graft from the Palm Ulnar Border (손날 부위에서의 전층 피부이식을 이용한 수부 피복)

  • Song, Jung-Yoon;Eun, Seok-Chan;Baek, Rong-Min
    • Archives of Plastic Surgery
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    • v.38 no.5
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    • pp.649-654
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    • 2011
  • Purpose: Split-or full-thickness skin grafts are used to reconstruct palmar skin and soft tissue defects after trauma or to release burn scar contracture on the hand. Glabrous skin defects should be substituted with similar skin to preserve function and aesthetics. The authors report their experiences with a technique that uses a full-thickness graft taken from glabrous skin on the ulnar edge of the palm for the reconstruction of soft tissue defects of the hand. Methods: During a three-year period from 2007 to 2010, 22 patients with burn scar contracture and 12 patients with post-traumatic skin defects on their hands were treated with full-thickness skin graft operations. The palmar skin and soft tissue defects after release of burn scar contracture or debridement of post-traumatic wounds were reconstructed with full-thickness skin grafts harvested from the ulnar border of their palms. All donor-site wounds were primarily closed. Results: The followup periods ranged from 3 to 25 months. Contractures of the hand were corrected without recurrence, and the grafts showed relatively good contour and color match to the adjacent fields. There were no reported complications such as significant color change or hypertrophic scarring. The grafted skin showed an average 5.9 mm static two-point discrimination obtained in fingertip reconstruction cases, indicating satisfactory reinnervation. Conclusion: Glabrous full-thickness grafts harvested from the palmar ulnar border is a very useful way of reconstructing soft tissue defects on hands, including fingertips, for function restoration, favorable aesthetic results, and low donor-site morbidity.

Neurovascular Island Graft for Finger Tip Loss (도서형 신경 혈관 피판을 이용한 수지의 피부 및 연부조직 결손의 재건술)

  • Chung, Duke-Whan;Han, Chung-Soo;Kim, Ki-Bong
    • Archives of Reconstructive Microsurgery
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    • v.10 no.2
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    • pp.99-104
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    • 2001
  • Purpose : Loss of sensibility over the finger tip resents a grave deficit and is an indication for sensible soft tissue reconstruction. This paper was performed to assess the long term results obtained by nerovascular island flap. Material and Methods : We performed neurovascular island graft for defective sensibility of finger tip loss in 94 cases since 1979 to 2000. The recipient sites were the thumb pulp defect in 79 cases, the amputated thumb in 9 cases, the amputated index in 4 cases, and the velar aspect of interphalangeal joint of thumb in 2 cases. The donor flaps were obtained from the radial side of ring finger in 63 cases, the ulnar side of the ring finger in 21 cases, and the ulnar side of the middle finger in 10 cases. A mean follow-up period was 5.7 years. Results : The flap quality was well vascularized and survived in 89 cases. The two-point discrimination was average 8.7mm. Because of scar contracture, the range of motion of the donor finger was decreased 3.5% of the normal finger in the distal interphalangeal joint, 8,2% in the proximal interphalangeal joint. A phenomenon of double sensibility occurred in 66 cases. Conclusion : This technique was excellent both aesthetically and functionally as a reconstruction of the Loss of fingertip.

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Surgical Options for Malignant Skin Tumors of the Hand

  • Yun, Min Ji;Park, Ji Ung;Kwon, Sung Tack
    • Archives of Plastic Surgery
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    • v.40 no.3
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    • pp.238-243
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    • 2013
  • Background Primary malignant tumors of the hand, although unusual, may present varied and often complex clinical problems. The main treatment modality of skin cancer of the hand has changed. Methods We retrospectively reviewed the medical records of 43 patients who underwent surgery for malignant skin tumors of the hand during an 18-year period, from September 1994 to February 2012. The characteristics of the tumor, methods of reconstruction, and long-term results were reviewed. Results We had 43 patients with 27 melanomas, 14 squamous cell carcinomas, and 2 sarcomas. Their ages ranged from 19 to 74 years (mean, $53.4{\pm}14.5$ years), from 46 to 79 years (mean, $59.7{\pm}9.6$ years), and from 15 to 43 years (mean, $29{\pm}19.8$ years), respectively. Thirty-four cases occurred on the fingertip (16 of those cases on the thumb), 5 cases occurred on the palm, and 4 cases on the dorsum of the hand. Amputation was most frequently used in early cases, but recently, tissue-sparing excision has been performed frequently. The incidence of local recurrence was 3 cases and distant metastasis was 1 case, and the 5-year survival rate was 100%, except in 4 cases due to follow-up loss. Conclusions The principles of treatment-to be curative and to preserve function and appearance-are important points. "Preservative surgery" preserves function and cosmesis of the involved finger or hand dorsum or palm. Preservative surgery not only emphasizes less resection and surgery of a smaller scale, but also optimal reconstruction of the soft tissue defect of the digit.

Case Report of Avulsion Amputation of Multiple Digits: Use of Rerouting the Transverse Digital Palmar Arch (가로손가락손바닥활을 이용한 다발성 벗겨짐 손상 손가락 재접합술 - 증례보고 -)

  • Kim, Jae-In;Choi, Hwan-Jun;Kim, Jun-Hyuk;Tark, Min-Seong;Kim, Yong-Bae
    • Archives of Reconstructive Microsurgery
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    • v.18 no.2
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    • pp.79-83
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    • 2009
  • Purpose: Avulsion injuries of digits have been presented for a long time as complex management problems. Despite of microsurgical advances, it is difficult to achieve good functional results and their management remains somewhat controversial. However, in a finger there are three transverse digital palmar arches. The middle and distal transverse digital palmar arches are consistently large(almost 1 mm) and may be used for arterial vessel repairs either proximally or distally, depending on the length and direction needed. 39-year-old man presented with avulsion amputation of the ulnar three digits, was operated using only arterial anastomosis with rerouting the transverse digital palmar arches. Methods: Replantation was performed using the artery-only technique. Because the digital arteries had been damaged, we did that the transverse digital palmar arches were transposed in an inverted Y to I configuration and were lengthened with rerouting them for the purpose of direct anastomosis of the digital artery. Venous drainage was provided by an external bleeding method with partial nail excision and external heparin irrigation. Results: The authors conclude that complete avulsion amputations with only soft tissue at the distal to insertion of the flexor digitorum superficialis tendon were salvageable with acceptable functional results. All three fingers survived. Conclusion: With technical advancements, the transverse digital palmar arches play an important role for finger amputation. Three digital palmar arches give us additional treatment option for the finger amputation. In this case, replantation with only-arterial anastomosis was successful and we obtained good aesthetic and functional outcome.

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A Modified Free Thenar Flap with Constant Innervations and Its Clinical Application (일관된 신경 지배를 위한 유리 무지구피판의 수정과 그의 임상 적용)

  • Han, Seung-Kyu;Yang, Jae-Won;Kim, Jin-Soo;Lee, Dong-Chul;Ki, Sae-Hwi;Roh, Si-Young
    • Archives of Plastic Surgery
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    • v.38 no.5
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    • pp.663-668
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    • 2011
  • Purpose: A modified free thenar flap was designed for coverage of volar finger defect with constant innervation using the palmar cutaneous branch of the median nerve. After clinical application of this flap, sensory results were evaluated in 6 cases. Methods: Patients were selected who have volar soft tissue defect with or without fingertip defect. The six cases of the innervated free thenar flap were performed since September 2009, and sensory outcomes were evaluated by the Semmes-Weinstein monofilament and two-point discriminator at four and half month after the surgery. Results: The Semmes-Weinstein Monofilament test revealed 3 cases showed 2.83, 1 case showed 3.61, 1 case showed 4.31 and 1 case showed 4.56. The static two-point discrimination test revealed 1 case showed 4 mm, 1 case showed 6 mm, 2 cases showed 9 mm, and 2 cases showed over 15 mm. The moving two-point discrimination test revealed 1 case showed 3 mm, 1 case showed 4 mm, 1 case showed 5 mm, 1 case showed 7 mm, and 2 cases showed over 15 mm. The donor sites showed no significant limitation of the thumb and neuroma formation. Conclusion: The innervated free thenar flap showed good sensory outcomes as a sensate free flap in a short time after surgery. It can be an option for coverage of volar finger defects that requires sensation.

Oblique Axis Hypothenar Free Flaps: Tips for Harvesting Larger Flaps with Minimal Donor Site Morbidity

  • Sang Ho Oh;Jae In Chung
    • Archives of Plastic Surgery
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    • v.50 no.3
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    • pp.279-287
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    • 2023
  • Background Hypothenar free flaps (HTFFs) have been widely used for reconstructing palmar defects. Although previous anatomical and clinical studies of HTFF have been conducted, this technique still has some limitations. In this study, we describe some tips for large flap design that allows for easy harvesting of HTFFs with minimal donor site morbidity. Methods A total of 14 HTFF for hand defect reconstruction were recorded. The oblique flap was designed in the proximal HT area following relaxed skin tension line along the axis between fourth web space and 10 mm ulnar side of pisiform. A flap pedicle includes one or two perforators with ulnar digital artery and HT branch of basilic vein. In addition, innervated HTFF can be harvested with a branch of ulnar digital nerve. Electronic medical records were reviewed to obtain data on patients' information, operative details, and follow-up period. In addition, surgical outcome score was obtained from the patient, up to 10 points, at the last follow-up. Results Mean harvest time was 46 minutes, and two perforators were included in 10 cases. The mean flap area was 10.84 cm2. There were no problems such as donor site depression, scar contracture, keloids, wound dehiscence, numbness or neuroma pain at donor sites, and hypersensitivity or cold intolerance at flap site, either functionally or aesthetically. Conclusion Palmar defect reconstruction is challenging for hand surgeons. However, large HTFF can be harvested without complications using the oblique axis HTFF technique. We believe our surgical tips increase utility of HTFF for palmar defect reconstruction.