Puncture Device Research Articles

Diagnosis and Treatment of Retroperitoneal Infection.

Background: Retroperitoneal infection is a persistent and widespread infectious disease that is difficult to treat. It is usually caused by secondary complications such as inflammation, damage, or perforation of adjacent organs in the retroperitoneal space. Pathogenic bacteria invade the retroperitoneal space through retroperitoneal and interstitial organs, peripheral tissue, and the blood. As a result, infections mostly arise from severe acute pancreatitis, acute colonic diverticulitis, inflammatory bowel disease, kidney abscess, and biliary tract injury. Initially manifested by the presence of lumbago, this disease spreads easily, is persistent, and is often misdiagnosed. Methods: Review and synthesis of pertinent literature and guidelines pertaining to abdominal infection and retroperitoneal infection. Results: Recent data indicate that mortality rates associated with retroperitoneal infection have been increasing annually. Early diagnosis and treatment have been shown to improve the prognosis. In the early stage, infection is insidious and lacks typical symptoms, and is primarily diagnosed with computed tomography (CT). Strategies that control the source of infection, rational use of antibiotic agents, and nutritional interventions are the primary approaches to treat the infections. Emergence of minimally invasive drainage technologies, including the ultrasound/CT-guided puncture and drainage, percutaneous nephroscope puncture and drainage, and drainage using a catheter through an abdominal puncture device (trocar) have shortened the treatment cycle and disease burden. However, current diagnosis and treatment for retroperitoneal infection are not sufficiently effective because some patients do not show typical clinical manifestations. Moreover, sensitivity and specificity of available auxiliary examination methods are not supported by sufficient evidence-based medical research. Additionally, there are no uniform standards on the timing of surgical intervention and treatment options. Therefore, we summarized the progresses on current diagnosis and treatment approaches for retroperitoneal infection.

An Overview of Anti-Eukaryotic T6SS Effectors.

The type VI secretion system (T6SS) is a transmembrane multiprotein nanomachine employed by many Gram-negative bacterial species to translocate, in a contact-dependent manner, effector proteins into adjacent prokaryotic or eukaryotic cells. Typically, the T6SS gene cluster encodes at least 13 conserved core components for the apparatus assembly and other less conserved accessory proteins and effectors. It functions as a contractile tail machine comprising a TssB/C sheath and an expelled puncturing device consisting of an Hcp tube topped by a spike complex of VgrG and PAAR proteins. Contraction of the sheath propels the tube out of the bacterial cell into a target cell and leads to the injection of toxic proteins. Different bacteria use the T6SS for specific roles according to the niche and versatility of the organism. Effectors are present both as cargo (by non-covalent interactions with one of the core components) or specialized domains (fused to structural components). Although several anti-prokaryotic effectors T6SSs have been studied, recent studies have led to a substantial increase in the number of characterized anti-eukaryotic effectors. Against eukaryotic cells, the T6SS is involved in modifying and manipulating diverse cellular processes that allows bacteria to colonize, survive and disseminate, including adhesion modification, stimulating internalization, cytoskeletal rearrangements and evasion of host innate immune responses.

Comparison of reverse puncture device and overlap in laparoscopic total gastrectomy for gastric cancer.

Background:Intracorporeal oesophagojejunostomy is one of the key steps in laparoscopic total gastrectomy (LTG). At present, there is no widely accepted anastomosis technique in oesophagojejunostomy.Materials and Methods:We retrospectively studied 63 patients with gastric cancer who underwent LTG. Two types of anastomosis techniques have been applied during LTG: the reverse puncture device (RPD) (28 patients) and overlap (35 patients).Results:A total of 63 patients (51 males and 12 females: mean age = 58 years and mean body mass index [BMI] = 26.3 kg/m2) were enrolled in this study. There were no significant difference in age, BMI, duration of surgery, duration of anastomosis, blood loss, post-operative hospital stay, tumour location, tumour size, degree of tumour differentiation, Borrmann type, total number of lymph nodes, number of positive lymph nodes, hospital stay, hospitalisation costs, intra-operative complications, post-operative complications and prognosis between the RPD group and the overlap group. RPD group showed a significant advantage in terms of the distance between the top border of tumours and the top resection margin (P < 0.001). We further found that the oesophageal lateral negative surgical margin distance of the upper gastric cancer in the RPD group was significantly longer than that in the overlap group (P < 0.001).Conclusions:Both the RPD and overlap techniques are safe and applicable in LTG. However, RPD has the advantage of obtaining an adequate safe margin compared with that of overlap technique, especially in patients with gastro-oesophageal junction carcinoma.

Laparoscopic preperitoneal tunneling technique using a novel device for peritoneal dialysis catheter placement.

We aimed to introduce the puncture technique based on a novel device for preperitoneal tunneling in laparoscopic PD catheter placement and to evaluate the safety and efficacy of this technique. This novel device was used in our center from May 2016. We conducted a retrospective analysis of patients undergoing laparoscopic PD catheter placement. The traditional method was performed in 20 patients and the novel procedure in 18 patients. A straight Tenckhoff PD catheter was placed in all patients. No intraoperative complications were encountered in both groups. Compared the traditional technique group, the procedure based on the novel device had a shorter operative time (49.2 ± 11.8 vs 53.9 ± 12.5). One patient in the traditional tunneling group underwent catheter obstruction. There were no pericatheter leakage, exit site and subcutaneous infection, hernia and peritonitis in the early postoperative days. No mortality was observed in these patients. The 6-month survival rate of the catheter was 100%. Laparoscopic preperitoneal tunneling technique is an effective way to implant intra-abdominal catheter. Our method based on a novel puncture device for preperitoneal tunneling is safe and efficient.

A new design puncture needle and a device of microcatheter protection for lumbar intrathecal catheterization in rats

Objective: To introduce a new design needle and a device of microcatheter protection for lumbar intrathecal catheterization in rats,and evaluate its feasibility and effectiveness.Methods: Sixty pathogen-free adult male Sprogue-Dawley rats were randomly divided into two groups(n=30 in each group), the control group (group C) and the modification group(group M). The traditional puncture device, 20G needle, was used in the group C without extemal shielding protection. The new design puncture needle and the microinjection cock were used in the group M. All rats were assessed for motor function on postoperative. The motor function was evaluated 1 day afteroperation. Lidocaine was injected in the catheter at 1st,3rd,7th,14th,21st day post-catheterization, methylene blue was injected in intrathecal at 30th day after operation, and the catheter location was observed. The paw withdrawal threshold(PWT) was measured at 1st,3rd,7th,14th,21st,30th day after operation, open-field test was tested at preoperative and one week postoperative for the purpose of evaluating the autonomous behavior of rats. Results: About motor function:level Ⅰ 75.9%,level Ⅱ 20.7%,level Ⅲ 3.4% in group C, and level Ⅰ 96.7%,level Ⅱ 3.3% in group M, Compared with group C,group M had higher percentage of the level Ⅰ in motor function (P＜0.05);Lidocaine test and methylen blue location showed that each one case of catheter was removed on the 14th and 21st day after intubation in group C, and total four cases were removed till the 30th day, while all catheters were in normal location in group M. There was significant difference between two groups in protection of the extemal portion of catheter(P＜0.05); The time of intrathecal injection in group M was only 1 minute, and it spent more than 3 minutes in group C. Compared with group C,the time of intrathecal injection is significantly shorter in group M(P＜0.01);PWT was reduced to the lowest on the third day after catheterization, and there was significant difference compared with preoperative(P＜0.05), PWT recovered on the 7th day and there were no significant difference between two groups; Compared with preoperative, there was no significant difference in the parameters of the group M in the open field test, neither between two groups. Conclusion: The new design puncture needle by its less injury and higher efficiency can be used in intrathecal catheterization. The microinjection cock is reliable and convenient for repeat injection with a perfect protection function of the external portion of catheter, meanwhile it has no impact on rats' autonomous behavior so that it is worthy of further promoting.

Development of Microneedle Puncture Device that Prevents Buckling of Needle by Delivery Operation

Herein, using the micromachining technology, we propose a microneedle delivery mechanism that is similar to the lead delivery mechanism for a mechanical pencil. This mechanism involves three parts: a needle grasping part, a needle advancing part, and a needle retainer. This mechanism advances the needle by repeating the following steps: 1) fix the needle in the grasping part; 2) simultaneously advance the grasping part and the needle using the advancing part; 3) release the needle from the grasping part; 4) retreat the grasping and the advancing parts to their initial positions. This operation advances the needle very slowly, thereby allowing the needle to puncture the skin without buckling, even if the needle has a narrow diameter. Each component of the puncture device was cut from a plastic plate using a femtosecond laser. We evaluated the performance of the device for a stainless steel needle of φ100 μm, and were successful in delivering the needle at approximately 100 μm/cycle under a no-load condition. We also succeeded in puncturing the same needle into a hydrogel (Young’s modulus of ∼0.08 MPa) using this device.

Natural orifice specimen extraction with a modified reverse puncture device technique for total laparoscopic colorectal resection: feasibility and efficacy

Objective: To evaluate the feasibility and efficacy of the modified reverse puncture device (mRPD) technique for transanal anastomosis in total laparoscopic colorectal resection with natural orifice specimen extraction surgery (NOSES).Methods: From August 2015 to September 2017, 34 patients underwent laparoscopic colorectal resection using the mRPD technique to place the anvil in the abdominal cavity and complete transanal anastomosis.Results: All patients who underwent total laparoscopic colorectal resection with NOSES were analyzed. The anvil placement time was 5–14 min, with an average of 6.7 min. The postoperative pain visual analogue scale (VAS) score was 1–4 points, with an average of 2.2 points. The postoperative hospital stay was 7–13 days, with an average of 8.7 days. No complications, such as anastomotic bleeding or stenosis, occurred. During a 14- to 28-month follow-up period (average, 19.5 months), no cases of long-term complications were observed.Conclusion: Total laparoscopic colorectal resection using mRPD is a technically feasible and safe procedure with satisfactory short-term efficacy.

Halo-pelvic traction combined with stageⅡsurgical correction for the treatment of severe and rigid scoliosis

To investigate the clinical effects of the Halo-pelvic traction combined with posterior instrumentation correction and internal fixation for the treatment of severe and rigid scoliosis. From January 2015 to 2019 May, 16 patients with severe and rigid scoliosis were treated by the Halo-pelvic traction combined with posterior instrumentation correction. There were 7 males and 9 females, aged 14 to 28 years with an average of 17.6 years, Cobb angle was 90° to 140° with an average of (108.84±17.93) °. Including congenital scoliosis in 10 cases (6 cases of dyssegmented scoliosis, 3 cases of dysplasia, 1 case of mixed scoliosis), idiopathic scoliosis in 4 cases and neurofibromatosis in 2 cases. All patients in group had scoliosis corrected by Halo-pelvic distraction combined with posterior instrumentation correction and internal fixation. Among them, 7 cases were treated with self-made guide device for iliac bone puncture, and the other cases with traditional bare hands. The height, scoliosis Cobb angle, kyphosis Cobb angle and correction rate of 16 patients before and after surgery were observed. The body height was corrected from (144.88±6.32) cm to (154.56±7.87) cm ; Cobb angle of scoliosis was corrected from (108.84±17.93) ° to (42.12±7.29) °, Cobb angle of kyphosis was corrected from (64.18±16.39) ° to (33.81±6.06) °. After the Halo pelvic traction, the body height increase, Cobb angle of scoliosis and kyphosis were changed with the mean of (7.06± 5.65) cm, (41.50±9.09)%, (30.52±9.66)%, respectively. After the stage Ⅱ surgical correction, the body height increase, Cobb angle of scoliosis and kyphosis were changed with the mean of (2.63±1.78) cm, (32.47±10.80)%, (15.55±9.47)% (The baseline Cobb angle referenced by the correction rate was the Cobb angle of the previous treatment). The body height increase and correction rate of Cobb angle of scoliosis and kyphosis with staged traction combined with surgery was (9.69±5.42) cm, (61.09 ± 5.03)%, (46.07±8.60)%. There was significant difference in body height increase, correction rate of Cobb angle of scoliosis and kyphosis between before and after each period of treatment (P<0.05). Treatment of severe and rigid scoliosis with Halo-pelvic traction combined with stage Ⅱ surgical correction can significantly correct deformities and improve appearance, and has fewer surgical complications and strong clinical operability.

A Puncturing Device that Mimics the Mechanism of Mosquito’s Proboscis and Labium - Verification of the Effect of Skin Deformation / Needle Buckling Prevention Mechanism and Puncture Experiment on Artificial Skin and Experimental Animals –

This paper proposes a mechanism for preventing needle buckling and skin deformation by mimicking the mosquito’s labium and discusses a puncturing device with a jig-integrated microneedle, based on the proposed mechanism. A sheet simplifying this mechanism was attached to an artificial skin’s surface, and experiments to puncture this artificial skin and corresponding finite element method (FEM) analysis were conducted. It was confirmed that the deformation of the puncture target and the puncture resistance force decreased with the use of the sheet. Based on these experimental and FEM-analytical results, a puncturing device with a jig-integrated needle has been designed and fabricated with 3D laser lithography. Experiments have been conducted with the fabricated device to puncture an artificial skin and the skin of a nude mouse to determine needle buckling prevention and the reduction in skin deformation. The study successfully samples blood from the mouse without stagnation of blood flow.

DESIGN AND PERFORMANCE EVALUATION OF PASSIVE INTERLOCKING POSTURE ADJUSTMENT MECHANISM FOR TRANSRECTAL ULTRASOUND PROBE

In the current prostate biopsy procedure, it is necessary for the doctor to hold the ultrasonic probe during the entire process. This increases the fatigue degree of the doctor, and the motion of the ultrasonic probe is more likely to cause damage to the anus of the patient. A medical device that can assist doctors in prostate scans and biopsy puncture devices was developed. We focused on the passive interlocking transrectal ultrasonic probe posture adjustment mechanism. Based on the posture adjustment mechanism, a passive interlocking transrectal ultrasound probe position and posture adjustment mechanism capable of assisting the doctor in prostate scanning and puncture intervention was designed. The passive interlocking posture adjustment mechanism with a seven-degree-of-freedom (DOF) interlocking mechanism was designed and can meet the requirements of doctors. The physical prototype of the passive interlocking transrectal ultrasonic probe posture adjustment mechanism was developed and commissioned. The locking torque and braking torque of the mechanism were measured. The results showed that the ultrasonic probe can achieve reliable locking and effectively meet the operation requirements.

Delivery of the Pseudomonas aeruginosa Phospholipase Effectors PldA and PldB in a VgrG- and H2-T6SS-Dependent Manner.

The bacterial pathogen Pseudomonas aeruginosa uses three type VI secretion systems (T6SSs) to drive a multitude of effector proteins into eukaryotic or prokaryotic target cells. The T6SS is a supramolecular nanomachine, involving a set of 13 core proteins, which resembles the contractile tail of bacteriophages and whose tip is considered as a puncturing device helping to cross membranes. Effectors can attach directly to the T6SS spike which is composed of a VgrG (valine-glycine-rich proteins) trimer, of which P. aeruginosa produces several. We have previously shown that the master regulator RsmA controls the expression of all three T6SS gene clusters (H1-, H2- and H3-T6SS) and a range of remote vgrG and effector genes. We also demonstrated that specific interactions between VgrGs and various T6SS effectors are prerequisite for effector delivery in a process we called “à la carte delivery.” Here, we provide an in-depth description on how the two H2-T6SS-dependent effectors PldA and PldB are delivered via their cognate VgrGs, VgrG4b and VgrG5, respectively. We show that specific recognition of the VgrG C terminus is required and effector specificity can be swapped by exchanging these C-terminal domains. Importantly, we established that effector recognition by a cognate VgrG is not always sufficient to achieve successful secretion, but it is crucial to provide effector stability. This study highlights the complexity of effector adaptation to the T6SS nanomachine and shows how the VgrG tip can possibly be manipulated to achieve effector delivery.

Reverse puncture device technique: an innovation of esophagojejunostomy in radical laparoscopic total gastrectomy.

Aim: To evaluate the feasibility, safety, short- and long-term efficacy of a reverse puncture device (RPD) technique for esophagojejunostomy in laparoscopic-assisted total gastrectomy. Patients & methods: This retrospective study analyzed outcome data of 104 patients in propensity score matching whom were divided into the RPD and the purse-string suture technique group. Results: The RPD group had a shorter anvil placement time, shorter operative time, longer resected esophageal length, shorter incision length, shorter postoperative drainage time, shorter postoperative hospital stay and anastomotic complications than the purse-string suture technique group (p <0.05). Multivariate analysis showed that BMI (odds ratio: 6.285, 1.446-27.322) and anvil placement time (odds ratio: 5.645, 1.089-29.321) were independent risk factors for anastomotic complications (p<0.05). Conclusion: Laparoscopic-assisted total gastrectomy using an RPD technique is feasible, safe and effective.

PHLEBITIS IN PERIPHERAL VASCULAR CATHETERS OF HOSPITALIZED PATIENTS

Objective: To identify the occurrence of mechanical and chemical phlebitis in peripheral venous catheters of hospitalized adult patients. Method: a descriptive observational study with 100 patients over 18 years of age who underwent peripheral venous puncture, performed in September and October 2016 at the Adult Hospitalization Unit of a University Hospital. The site of insertion of the peripheral puncture device was evaluated daily in order to identify signs and symptoms of phlebitis. Statistical analysis was performed using the chi-square test, considering statistical significance when p &lt;0.05. Results: Phlebitis occurred in 21% of cases, with grade 1 (52.4%) prevalent. Of the 21 cases, 14 occurred due to mechanical causes, 50% due to repeated punctures and 7 due to chemical causes, which presented a statistically significant value in relation to some medications used (p = 0.008). Conclusion: the result of the study made the importance of the multiprofessional team in the care of these patients perceptible.

Study and Analysis on the Test of Representative Products for Percutaneous Renal Puncture Device

Percutaneous renal puncture device has very important clinical value. Qualified percutaneous renal puncture device is one of the important ways to evaluate its safety and efficacy, and it is also an important prerequisite for the device to be marketed in China. When manufactuers test the product, the selection of representative products is suggested from the aspects of performance parameter, structure, material and production process.

Crystal Structures of R-Type Bacteriocin Sheath and Tube Proteins CD1363 and CD1364 From Clostridium difficile in the Pre-assembled State.

Diffocins are high-molecular-weight phage tail-like bacteriocins (PTLBs) that some Clostridium difficile strains produce in response to SOS induction. Similar to the related R-type pyocins from Pseudomonas aeruginosa, R-type diffocins act as molecular puncture devices that specifically penetrate the cell envelope of other C. difficile strains to dissipate the membrane potential and kill the attacked bacterium. Thus, R-type diffocins constitute potential therapeutic agents to counter C. difficile-associated infections. PTLBs consist of rigid and contractile protein complexes. They are composed of a baseplate, receptor-binding tail fibers and an inner needle-like tube surrounded by a contractile sheath. In the mature particle, the sheath and tube structure form a complex network comprising up to 200 copies of a sheath and a tube protein each. Here, we report the crystal structures together with small angle X-ray scattering data of the sheath and tube proteins CD1363 (39 kDa) and CD1364 (16 kDa) from C. difficile strain CD630 in a monomeric pre-assembly form at 1.9 and 1.5 Å resolution, respectively. The tube protein CD1364 displays a compact fold and shares highest structural similarity with a tube protein from Bacillus subtilis but is remarkably different from that of the R-type pyocin from P. aeruginosa. The structure of the R-type diffocin sheath protein, on the other hand, is highly conserved. It contains two domains, whereas related members such as bacteriophage tail sheath proteins comprise up to four, indicating that R-type PTLBs may represent the minimal protein required for formation of a complete sheath structure. Comparison of CD1363 and CD1364 with structures of PTLBs and related assemblies suggests that several conformational changes are required to form complete assemblies. In the sheath, rearrangement of the flexible N- and C-terminus enables extensive interactions between the other subunits, whereas for the tube, such contacts are primarily established by mobile α-helices. Together, our results combined with information from structures of homologous assemblies allow constructing a preliminary model of the sheath and tube assembly from R-type diffocin.

A New Adjustable Puncture Device for In Situ Fenestration During Thoracic Endovascular Aortic Repair

Purpose: To describe a new adjustable puncture system for in situ fenestration in thoracic endovascular aortic repair (TEVAR). Technique: An adjustable puncture needle for use in conjunction with a steerable 8-F, 55-cm Fustar sheath is demonstrated in a 65-year-old man with acute complicated type B dissection involving the left subclavian artery (LSA). The puncture device features an inflatable balloon at the tip, a central lumen for 0.018-inch guidewires, and a 3-level puncture depth. After thoracic stent-graft deployment at zone 2, the needle/sheath combination was delivered from a left brachial artery access. The needle was adjusted perpendicular to the fabric of the stent-graft with the assistance of the steerable sheath. The balloon at the tip was inflated to center the needle, and the puncture depth was selected on the puncture needle system. Holding the sheath and puncture needle together, a hole was created in the graft fabric. The aperture was sequentially dilated to accommodate the mating stent selected to maintain perfusion to the LSA. This new device has been successfully applied in 6 patients treated with TEVAR for different arch pathologies. Conclusion: This new puncture device could assist in situ fenestration and improve the technical success rate.

4:21 PM Abstract No. 220 EZ-Access, a novel 3D printed groin puncture device: no imaging needed!

Exsanguination is the leading cause of death after vascular trauma. Resuscitative endovascular balloon occlusion of the aorta (REBOA) can control torso hemorrhage. However, adoption of this approach specifically by the military has been limited by challenges in achieving femoral artery access in austere combat environments. To address this need, we developed a novel 3D printed minimally invasive device, termed EZ-Access, to enable successful vascular access without the need for ultrasound guidance or specialized training for use in the field by first responders. EZ-Access was modeled using SolidWorks and 3D printed with a methacrylated resin using FormLabs2 printer. The device measured 14 × 2 × 1cm with two concave thumb rests on either side of a central plate containing 6 equidistant holes spaced at 0.8cm. The holes were fitted with a variable number of 21-gauge 7cm percutaneous entry needles followed by extensive testing. Multiple trials involved IR staff, residents, college and high school students to test success of accurate access of femoral artery using SimuLab models (Seattle, WA). Trial 1 consisted of 3 needles in alternating holes (n = 40). Trial 2 used 6 sequentially placed needles (n = 42). The needles within the device were inserted without ultrasound (US) guidance, two fingerbreadths lateral to the pubic symphysis. The device was angled along the groin crease and the needles entered the skin at 45 degrees. After each puncture, US was used to confirm vessel entry. A control trial was also performed using standard single-entry access needle (n = 5) by staff IR. Statistical analysis performed using Prism software (P = 0.05). The control trial demonstrated vessel entry rate of 20%. Using 3 alternating needles, successful vessel entry increased to 40% (P = 0.396). With 6 sequential needles, vessel entry success significantly increased to 100% (P <0.001) regardless of operator experience. EZ-Access has demonstrated overwhelming success in obtaining consistent percutaneous vascular access in a simulated clinical scenario independent of the operator’s experience without the need for imaging guidance. The device has promising applications in prehospital resuscitation.

Application of CT-guided self-made localization puncture device in radiofrequency ablation of liver tumors

Objective To evaluate the value of CT-guided self-made positioning puncture device in radiofrequency ablation of liver tumors. Methods A total of 78 tumor foci from 64 patients with primary hepatocellular carcinoma treated with radiofrequency ablation from January 2010 to November 2014 were analyzed. Among them, 13 tumor diameters were 3.5-5.0 cm and 65 < 3.5 cm. The location and puncture of tumor lesion were performed by CT-guided positioning device, and the effect of puncture and lesion was evaluated by using tumor precise radiotherapy planning system. Radiofrequency ablation of tumor lesion was performed by tumor radiofrequency treatment system. Results The puncture error of all tumors in the space was 1-4 mm, the average puncture error was 2.9 mm, the complete ablation rate of tumor lesions was 93.59% (73/78), and there was no serious complication in the course of treatment. After treatment, the alpha-fetoprotein and liver function were significantly improved, and the differences were statistically significant (both P < 0.05). At 1 month after surgery, CT found that no tumor and ablation was enhanced, at 3 months after surgery, CT showed that the arterial phase of all the tumor lesions did not strengthen, all of them were low-density lesions, no ablation recurred. The recurrence rates of 1, 2, 3, and 4 years after treatment were 17.9%, 29.9%, 45.9% and 55.0%. Conclusion CT-guided radiofrequency ablation with self-made puncture device is effective in the diagnosis of primary liver cancer, ablation is complete and safe. Key words: Ablation techniques; Liver neoplasms; Tomography, X-ray computed; Homemade needle positioning device

Superficial Automated Keratopigmentation for Iris and Pupil Simulation Using Micronized Mineral Pigments and a New Puncturing Device: Experimental Study.

To study the outcomes and tolerance of micronized mineral pigments for corneal tattooing, using a superficial automated keratopigmentation (SAK) technique in an experimental animal model and a new puncture device to inject the pigments into the corneal stroma. Forty eyes of 40 New Zealand rabbits were included in this study. The animals were divided into groups A and B. Both groups underwent SAK using a new automated keratopigmentation device. Micronized mineral pigments were injected through the epithelium into the corneal stroma to replicate the iris color in 25 eyes (group A), and black color was used to replicate the pupil in 15 eyes (group B). Slit-lamp examination was performed to evaluate the outcome. Histopathological examination was also performed to ascertain the presence of pigment dispersion, inflammation, and/or neovascularization. All 40 eyes showed good cosmetic appearance after keratopigmentation. No intraoperative complications were detected. At the first week, mild or moderated conjunctival injection was observed in 13 eyes and transitory corneal epithelial defects were also detected in 27 eyes. Examination was unremarkable 2, 4, and 6 months after surgery. No neovascularization was detected in any case in the histopathology study. SAK using a new automated puncture device and micronized mineral pigments achieved good cosmetic outcomes for iris and pupil simulation. This method could be a valid alternative to treat serious cosmetic eye problems that affect the superficial cornea or functional problems, such as photophobia or diplopia secondary to iris defects or trauma.

Study on Automatic Venipuncture Device and Control system

According to clinical PICC(Peripherally Inserted Central Catheter) catheter surgery, this project introduces a new scheme for vein puncturing device and its controlling system. This device adopts ultrasonic image guided by the microcontroller, to achieve automatic venous catheterization. This kind of automatic vein puncture device adopts double stepping motors and screws as its transmission. One motor drives the needle and the hose to puncture into vein through skin. The other one drives the hose to specified location, then triggers withdrawal button and then the needle withdraws back into its cylinder. Several key points were set in the process of puncturing, the velocity period and the acceleration period can be preselected respectively. Moving distance and velocity of the needle in vein puncturing were setup automatically according to diameter and depth of the vein, achieving controlling puncturing and placing hose accurately.