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At least 19 recordsLinked to original sources

PubMed2001

Comparison of piezo-assisted micromanipulation with conventional micromanipulation for intracytoplasmic sperm injection into human oocytes.

OBJECTIVE: To compare the efficacy of piezo-assisted micromanipulation with conventional micromanipulation for intracytoplasmic sperm injection (ICSI) into oocytes in patients with impaired semen parameters and no success with in vitro fertilization (IVF). STUDY DESIGN: A retrospective randomized study was conducted on 204 cycles for 104 couples with piezo-assisted ICSI and 122 cycles for 96 couples with conventional ICSI. Piezo-assisted ICSI consists of two steps, namely penetration of the zona pellucida alone with a piezo-pulse and then puncturing of the oolemma with a light negative pressure without piezo, as with conventional ICSI. The tips of injection pipettes were prepared after pulling by breakage with a scalpel under a microscope, so that the inner diameter at and near the tip was 5 microm, as for conventional ICSI. RESULTS: Piezo-assisted ICSI demonstrated significantly more favorable results, with a fertilization rate of 90.3% (conventional ICSI: 83.1%, p < 0.01) and a cleavage rate of 88.1% (conventional ICSI: 84.6%, p < 0.01). CONCLUSION: Piezo-assisted ICSI is easy to incorporate a spermatozoa exactly into the ooplasm with little deformation of the oocyte during insertion. Piezo-assisted ICSI can be used effectively for human oocytes to improve the fertilization, cleavage rates.

Adult↗

PubMed2000

Micromanipulation of cryopreserved embryos and cryopreservation of micromanipulated embryos in PGD.

The possibility to employ cryopreservation in Preimplantation Genetic Diagnosis (PGD) should enlarge the opportunities for research and clinical activity. For these purposes, we tried three kinds of approaches on human abnormal embryos: (1) cryopreservation of biopsied embryos; (2) biopsy of thawed embryos; and (3) biopsy of embryos derived from thawed oocytes. Our preliminary results show that: (1) biopsy of thawed embryos is feasible and FISH analysis is possible on both survived and lysed cells; (2) Optimization of freezing/thawing procedures are necessary to obtain better survival rate after thawing of biopsied embryos; (3) Biopsy and FISH are feasible on embryos derived from thawed oocytes and they could be a good way to study the chromosomal arrangement of these poorly investigated embryos.

Biopsy↗

PubMed1993

Analysis of factors contributing to success in a program of micromanipulation-assisted fertilization.

OBJECTIVE: To determine factors important to clinical success in micromanipulation-assisted in vitro fertilization (IVF). DESIGN: Procedures invoked in two separate series of micromanipulation-assisted IVF cycles, one unsuccessful (series I) and the other successful (series II), were compared in an effort to identify changes that led to clinical success. SETTING: University-based IVF clinic. PATIENTS: In both IVF series involving micromanipulation, patients consisted of infertile couples who fit any of five categories of male-factor related infertility. The female patients underwent controlled hyperstimulation for oocyte retrieval and the oocytes were inseminated normally or were subjected either to partial zona dissection or subzonal sperm insertion to assist fertilization. Results in all groups were compared between the two patient series. RESULTS: In the successful series II, a noticeable improvement in fertilization rate and embryo quality was observed compared with series I. A significant increase in the percentage of patients reaching embryo transfer, the pregnancy rate per transfer, and the pregnancy rate per retrieval were noted in series II; a 25% ongoing pregnancy rate per retrieval was observed overall in this successful group, with "ongoing" defined as manifestation of at least a fetal sac on ultrasound with no detectable problems. Patients with a mixed transfer of embryos derived from manipulated and normally inseminated oocytes had a 75% rate of pregnancy per transfer in series II. Differences between the two series could not be attributed to patient selection or biases in selection of oocytes relegated to micromanipulation. However, oocyte handling, micromanipulation, and culture protocols differed significantly between the two series in that temperature and pH of oocytes was better controlled, and micromanipulation time was minimized in series II. CONCLUSION: Success in micromanipulation depends on maintenance of the oocyte in a stable and supportive environment throughout the micromanipulation procedure. It is also important to minimize trauma to the eggs by performing micromanipulation rapidly and with minimal distortion of the egg. Patients with a poor fertilization rate in standard IVF may experience a substantial increase in the likelihood of pregnancy when micromanipulation-assisted fertilization is performed on some eggs.

Cleavage Stage, Ovum↗

PubMed2003

Micromanipulator: effectiveness in minimally invasive neurosurgery.

Minimally invasive surgeries by innovative approaches are practiced in all fields. The evolution of microneurosurgery has revolutionized the results in neurosurgery. Use of endoscopes and navigation has made microsurgery less invasive. Another development to make minimally invasive microneurosurgery further lesser invasive is the use of micromanipulator. The use and effectiveness of manually controlled micromanipulator system is presented. The manually controlled micromanipulator system consists of three parts, i.e., a basic micromanipulator, manipulator supporting device and the manual control. The micromanipulator fitted in supporting device is arranged before the start of surgery. The supporting device used is pneumatically driven powered endoscopic holding device (Mitaka Kohki Co., Tokyo) In maximum number of times we used the system for endoscopic assisted cerebrovascular microneurosurgery. In a span of two months we used it in thirty aneurysm clipping surgeries. The endoscope fitted in system has three ranges of motions (forward/backward, upside/down and sideways). We use MACHIDA rigid endoscope with internal diameter of 2.7 mm (smallest diameter endoscope available). Special features of this endoscope are accurate visualization at a deeper plane, stable movements and availability of single focus point for long time. All these features are valuable during pre- and postoperative clipping observation. The aim of development of micromanipulator system was to further reduce invasiveness. A significant improvement in manual dexterity is possible when working through the micromanipulator interface, which dampens human physiological tremor. The physiological tremor would render the manual dexterity unsafe at the end of lever arm of long instruments. Thus, the use endoscope becomes practical. The minimally invasive microneurosurgery can be further made lesser invasive by use of micromanipulator and we are convinced that this will facilitate more accurate and promising results in microneurosurgery.

Cerebral Revascularization↗

PubMed2003

Retrospective case study of carbon dioxide laser stapedotomy with lens-based and mirror-based micromanipulators.

Most clinical studies on carbon dioxide (CO2) (lambda = 10.6 mm) laser stapedotomy have been carried out with the laser guided by a conventional lens-based micromanipulator, with the attendant risks of correct aiming (HeNe) and surgical (CO2) beam misalignment. Hence, engineering advances have attempted to improve laser targeting as well as the spot size focus. The development of the mirror-based micromanipulator was a response to this need but no data concerning its use in stapes surgery is available. We performed a retrospective case-series review of patients treated for otosclerosis between 1992 and 2000. Primary laser stapedotomy was performed in 218 consecutive patients. In the first 78 procedures, the aiming beam (HeNe, lambda = 632 nm) and surgical beam (CO2) were guided with a conventional lens-based micromanipulator whereas in the subsequent 140 procedures, they were guided by using a mirror-based micromanipulator. Hearing was tested at six and 12 months. The mean (SD) airbone gap was 5 dB (4.5) and 4.5 dB (3.9). The mean closure was 15 dB (9.9) and 14.4 dB (9.4). The mean change in the high-tone bone-conduction level was 5.5 dB (7.3) and 7.8 dB (7.5). Overheating of the facial canal produced transient facial paralysis in one case and was due to misalignment of the beams with the lens-based micromanipulator. Use of the mirror-based micromanipulator obviated the need to verify alignment. The light-weight and superior optical yield of this system made it possible to reduce the number of impacts on the footplate by the integral restitution of the energy source. This study demonstrated that the CO2 laser is an effective method for performing stapedotomy. In addition, microtrauma to the labyrinth is reduced by its ability to perform calibrated footplate fenestration without mechanical or vibrational injury to the inner ear. The optical reflection micromanipulator simplified beam alignment and enhanced surgical comfort.

Adolescent↗

PubMed1994

Successful in vitro fertilization and pregnancy by micromanipulation with epididymal sperm.

PURPOSE: To examine the effectiveness of micromanipulation on the treatment of the patients with obstructive azoospermia, subzonal insemination or partial zona dissection was performed using epididymal sperm of the 23 patients, and the in vitro fertilization and embryo transfer (IVF-ET) outcomes were analyzed. RESULTS: Fertilized oocytes were obtained in 11 cycles of the 25 treated cycles, and six pregnancies were established by the subsequent ET. Through the analysis of 13 cycles in which both the micromanipulation and usual IVF insemination were performed, the fertilization rate per oocyte with the micromanipulation [25% (28/113)] was significantly higher than that with the usual insemination method [4% (4/102)]. The micromanipulation was most useful for the treatment of the patients with congenital absence of the vas deferens. Moreover, there was no need to aspirate a large volume of the epididymal fluid, but it was essential to prepare more than 10 mature oocytes retrieved. CONCLUSIONS: These results indicate that micromanipulation with epididymal sperm is an effective treatment for obstructive azoospermia, and careful preparations of sperm and well-controlled ovarian hyperstimulation are necessary for successful IVF-ET.

Adult↗

PubMed1993

Micromanipulation by "multiple" optical traps created by a single fast scanning trap integrated with the bilateral confocal scanning laser microscope.

We have developed a novel micromanipulator consisting of multiple optical traps created by scanning one single beam trap along a variable number of positions. Among other things, this enables the orientation of irregularly shaped and relatively large structures which could not be oriented by just one trap as is demonstrated on long Escherichia coli bacteria filaments. We expect that the multiple trap manipulator will broaden the field of applications of optical trapping as a micromanipulation technique. For example, it facilitates the study of mechanical properties of extended structures as illustrated by a "bending"-experiment using E. coli bacterium filaments. A special application of the multiple trap manipulator is the "indirect trapping" of objects which we did by keeping them held between other optically trapped particles. Indirect trapping makes it possible to trap particles which either cannot be trapped directly due to their optical properties (refractive index) or for which exposure to the laser radiation is undesirable. The multiple optical trap manipulator is controlled interactively by a UNIX workstation coupled to a VME instrumentation bus. This provides great flexibility in the control of the position and the orientation of the optical traps. Micromanipulation makes it desirable to have real time 3D microscopy for imaging and guidance of the optical traps. Therefore we integrated optical micromanipulation and a specially developed real-time confocal microscope. This so called bilateral confocal scanning laser microscope (bilateral CSLM) [Brakenhoff and Visscher, J Microsc 165:139-146, 1992] produces images at video rate.

Lasers↗

PubMed1992

Subzonal insemination of a single mouse spermatozoon with a personal computer-controlled micromanipulation system.

A personal computer-controlled micromanipulation system was developed for automatic injection of spermatozoa into the perivitelline space of mouse ova. A pair of three-dimensional hydraulic micromanipulators driven by pulse motors was used for this automatic system. The pulse signals that regulate the motors are initiated by the computer program, and these signals cause the micromanipulator to move the microtool precisely. The computer program was designed to perform the most effective movements of the sperm injection needle used during manual micromanipulation. Prior to the manipulation, the computer locates the tip of the injection needle and the end of the egg-holding pipette in the microscope field using image processing. The trajectory of the injection needle is determined according to these initial positions. Using this robotic system, subzonal insemination with a single mouse spermatozoon was attempted in a total of 143 ova. The sperm insertion was successfully completed in all cases without damaging any of the ova. Spermatozoa treated with ionophore A23187 and those without the treatment were used. The fertilization rate (68.8%) of the ova inseminated with treated sperm was significantly higher than that (37.5%) obtained with the nontreated sperm (P less than 0.05). These findings suggest the feasibility and potential for further applications of a robotic microinsemination system and, in addition, that a higher fertility rate in the subzonal insemination of mouse ova can be achieved with the ionophore treatment of spermatozoa.

Animals↗

PubMed2001

Reaction of the skin fibroblast cytoskeleton to micromanipulation interventions.

Micromanipulation is a strong mechanical intervention into cellular integrity and induces large changes in the fine structure of the treated cells. Human diploid skin fibroblasts (KF1 and KF2 cell lines) were chosen as an experimental model. Special hatching needles were used for defined micromanipulation interventions (deformation of plasma membrane). Changes in cytoskeletal structures were visualized by using fluorescent and confocal microscopy. The actin cytoskeleton showed a more sensitive response to micromanipulation than microtubules. Characteristic changes in microfilaments, i.e., thickenings and knot formation, were visible in treated cells fixed immediately after micromanipulation and were the result of hatching-needle pressure on the plasma membrane as well as a reaction of actin filaments localized near the plasma membrane deformation. These direct changes and also other specific alterations in the actin filament network were detectable 14 to 16 h after treatment, but they were not observed when longer reparation intervals were used.

Actin Cytoskeleton↗

PubMed1998

A new assisted hatching technique using a piezo-micromanipulator.

OBJECTIVE: To estimate the efficacy of a new assisted hatching technique using a piezo-micromanipulator to support embryonic implantation. DESIGN: Sibling spare embryos from human cycles of IVF were allocated to either a treated group for assisted hatching by a piezo-micromanipulator or a nontreated control group. SETTING: The Infertility and IVF unit of the Kyoto University Hospital. PATIENT(S): Sixty-eight women undergoing conventional IVF treatment. INTERVENTION(S): One hundred ten spare 4- or 8-cell embryos from 68 patients undergoing IVF were treated with the new assisted hatching technique, and the results were compared with those obtained for 112 sibling embryos without the treatment. In the assisted hatching procedure, zona thinning combined with drilling was performed by the vibration of a microneedle produced by the piezo-micromanipulator unit. MAIN OUTCOME MEASURE(S): The rates of partial hatching and completely hatched blastocysts. RESULT(S): The rates of hatching and of hatched blastocysts per total developing blastocysts were significantly higher in the treated group (86.7% and 33.3%, respectively) than in the control group (15.3% and 2.8%, respectively). CONCLUSION(S): These results demonstrate that the newly devised zona thinning and drilling technique using a piezo-micromanipulator is useful for assisted hatching.

Blastocyst↗

PubMed1995

Micropuncture retrieval of epididymal sperm with in vitro fertilization: importance of in vitro micromanipulation techniques.

OBJECTIVES: To evaluate the importance of in vitro micromanipulation techniques, specifically intracytoplasmic sperm injection (ICSI), for the fertility treatment of men with congenital absence of the vas deferens (CAV) or other unreconstructable male reproductive tract obstruction. METHODS: Results using ICSI during in vitro fertilization (IVF) were compared to previously published results of IVF alone and IVF with other micromanipulation techniques at the same infertility center. Main outcome parameters evaluated were: fertilization rate per oocyte, clinical pregnancy rate, and ongoing pregnancies and deliveries. RESULTS: IVF with ICSI yielded a fertilization rate per oocyte of 140 of 312 (45%) and a clinical pregnancy rate of 14 of 27 (52%) per cycle of sperm and egg retrieval. Ongoing pregnancies or deliveries have occurred for 13 of 27 (48%) cycles with ICSI. These results were better than our previously published results of IVF alone or in conjunction with the micromanipulation techniques of subzonal insertion (SuZI) or partial zona dissection (PZD) that yielded a 119 of 631 (19%; P < 0.0001) fertilization rate, clinical pregnancy rate of 14 of 51 (27%; P < 0.001) and ongoing pregnancy or delivery for 12 of 51 cycles (24%; P < 0.001). CONCLUSIONS: Epididymal sperm retrieval should be performed only when micromanipulation is available in conjunction with IVF to maximize chances of fertilization and subsequent pregnancies. The use of ICSI for epididymal sperm appears to maximize chances of pregnancy for couples with surgically unreconstructable obstructive male infertility.

Cytoplasm↗

PubMed2000

Is the timing of implantation affected by zona pellucida micromanipulation?

PURPOSE: Our purpose was to examine the timing of implantation and early embryo development following uterine transfer of oocytes/embryos previously subjected to zona pellucida micromanipulation. METHODS: A total of 68 singleton pregnancies resulting from IVF and embryo transfer with/without micromanipulation. Patients were divided into four groups according to the type of micromanipulation technique: assisted hatching, embryo biopsy, intracytoplasmic sperm injection, and no micromanipulation (control group). Serial serum beta-hCG levels were measured between 10 and 25 days after fertilization and log-transformed. Linear regression analyses were performed and extrapolated to hCG = 10 mIU/ml (hCG10) to estimate detectable implantation. The slopes of the regression lines were used to estimate the rising speed of hCG, an indirect sign of embryo development. RESULTS: There were no significant differences among groups with respect to hCG10, the slopes or intercepts of the regression lines. CONCLUSIONS: Various oocyte/embryo microsurgical procedures used in ART involving zona pellucida manipulation do not appear to affect the timing of implantation or early embryo development.

Adult↗

PubMed2002

The effect of optical design on micromanipulator spot size using CO2 laser irradiation.

OBJECTIVE: The study goal was to compare the laser spot size created using reflective and refractive micromanipulators with a CO(2) laser and to determine the sensitivity of spot size to laser power. STUDY DESIGN AND SETTING: A CO(2) laser and operating microscope (400-mm focal length) was coupled to either a reflective (Cassegrain-like) or refractive micromanipulator. Laser spot size was determined by measuring the region of ablation created by laser irradiation of wood (dry tongue depressors), exposed photographic film, and agar gel using optical micrometry. Laser power varied from 0.5 to 20 W with pulse durations of 0.1 and 0.5 second. RESULTS: The reflective micromanipulator demonstrated overall smaller spot sizes for a given laser power and lower incremental change in spot size with increasing power. The reflective design demonstrated less sensitivity to increases in laser power. CONCLUSIONS: Micromanipulator optical design can result in significant differences in laser spot size. The reflective device used in this study demonstrated less sensitivity to increasing laser power.

Algorithms↗

PubMed2003

Feasibility of using the potassium titanyl phosphate laser with micromanipulators in robotic neurosurgery: a preliminary study in the rat.

OBJECT: Robotic surgery can be used as a novel technology in ultramicrosurgery. A microscopic-manipulator (micromanipulator) system, which has a rigid neuroendoscope and three guiding manipulators, was developed in Japan for less invasive telerobotic neurosurgery. To apply this system in a clinical setting, it is necessary to confirm that it is capable of performing various surgical procedures including cutting, coagulation, and bleeding control. The authors chose the potassium titanyl phosphate (KTP) laser for such procedures. The aim of this paper was to evaluate the feasibility of this system mounted with the KTP laser. METHODS: A prototypical micromanipulator system was tested in rats. Two kinds of in vivo experiments were performed using the KTP laser: coagulation and biopsy. The coagulated lesions were precisely aligned and their maximum depths were proportional to the energy applied during the coagulation experiment. The diagnosable specimens were obtained during the biopsy experiment. The micromanipulator system was able to perform all surgical procedures accurately. There was no complication relating to the use of the micromanipulator system such as brain injury or uncontrollable bleeding. CONCLUSIONS: The results from this study proved that this system works precisely and safely and will become a new neurosurgical tool in managing lesions that are difficult to treat using conventional microsurgery or neuroendoscopic surgery.

Animals↗

PubMed1992

Micromanipulation of gametes and embryos in preimplantation genetic diagnosis and assisted fertilization.

Recent advances in micromanipulation and biopsy of gametes and embryos have made it possible to develop new approaches for early genetic diagnosis and prevention of genetic disease and for treatment of severe male-factor infertility. Preimplantation diagnosis of a number of X-linked and autosomal recessive disorders has been performed, using polar body sampling and blastomere biopsy, coupled with polymerase chain reaction. Blastocyst biopsy has also been performed in human embryos; however, there has been no clinical application so far. Existing data have not shown any detrimental effect of micromanipulation and biopsy involved in the preimplantation development of the human embryo. The existing experience on micromanipulation of gametes (zona-opening procedures, subzonal sperm insertion, and sperm microinjection into the ooplasm) has also demonstrated the clinical usefulness in assisted fertilization, suggesting a possible selective application of various micromanipulation techniques and their combinations in male infertility.

Biopsy↗

PubMed1995

Micromanipulation at an infertility centre.

AIM: Human in vitro fertilisation (IVF) and gamete intrafallopian transfer have been used in the management of various forms of infertility. In cases of severe male-factor infertility, fertilisation can be a factor. In this study micromanipulation was used to increase fertilisation in such cases. METHODS: Two micromanipulation techniques, subzonal sperm injection (SUZI) and partial zona dissection (PZD), were used to assist fertilisation in patients with abnormal semen parameters. Ten couples with severe oligo-, terato- and asthenozoospermia participated in the SUZI programme. Seventy-three oocytes were obtained from these 10 patients. PZD was used on day 1 oocytes in cases of male infertility as well as a rescue attempt on day 2 oocytes when fertilisation had failed after routine insemination. RESULTS: The SUZI technique had a fertilisation rate of 37.7%. In this group, a biochemical pregnancy was achieved. Differences between the fertilisation rate of conventional IVF (33.3%) and PZD (56.3%) in cases of male infertility, were not statistically significant although a clinical difference could be detected. PZD was statistically effective in facilitating fertilisation (37.5% v. 8.3%) in couples where this procedure was introduced to reinseminate 24-hour-old unfertilised oocytes. Four patients received PZD reinseminated embryos. An average of 1.45 PZD embryos were replaced and 1 implantation pregnancy was confirmed. CONCLUSION: The micromanipulation results are encouraging and seemed to increase the efficiency of IVF in humans. Furthermore, our data support the conclusion that micromanipulation procedures can bring about pregnancies.

Female↗

PubMed1998

[An osseointegrated micromanipulator as anchor for implantable hearing aid transducers. 1: Fitting to the surgical anatomy of the temporal bone and surgical technical properties].

The first electronic implantable hearing aids for patients with hearing loss are coupled to the ossicular chain or perilymph during implantation and are now available. Our new Tübingen implant designed for sensorineural hearing loss (SNHL) is the combination of an implantable microphone and piezotransducer. To avoid hearing losses during implantation, the Tübingen piezotransducer will be (1) fixed to the mastoid cavity and (2) positioned to one of the ossicular target points. This can be done with a micromanipulator which will be implanted together with transducer and microphone in the mastoid cavity. The manipulator weights 0.7 g. With four degrees of freedom, it allows highly secure and safe positioning of the transducer's probe tip to the ossicular chain under close to stereotactic conditions. The main advantages of the present micromanipulator are (1) easy handling during surgery, (2) the transducer's precise positioning to the ossicular target point with sufficient degrees of freedom, and (3) the transducer's stable fixation in the mastoid cavity in the final position. Following integrated safety as the leading principle, ossicular or inner ear injuries caused, e.g., by the patient's head movement or unintentional manual contact by the surgeon, are minimized. The micromanipulator is, as it were, the surgeon's vibration-free "artificial hand". The manipulator's development and its optimization to the mastoid cavity by test implantation in 50 human temporal bones are shown in detail. While coupling the transducer to the body of the incus, transducer, microphone, and micromanipulator can be implanted into 76% of all mastoid cavities without protrusion. In the case of transducers coupling to the long process of the incus, the protrusion-free implantation rate of the above-mentioned three implant modules is 78%.

Bone Plates↗

PubMed1992

Electroejaculation in combination with in vitro fertilization and gamete micromanipulation for treatment of anejaculatory male infertility.

OBJECTIVE: Failure to ejaculate may be overcome by use of electroejaculation. However, such semen samples are often unsuitable for therapies like intrauterine insemination. The combination of electroejaculation with in vitro fertilization, including gamete micromanipulation, should improve chances of fertilization and pregnancy in such cases. STUDY DESIGN: Within a private infertility clinic electroejaculation in combination with intrauterine insemination was carried out in 18 cycles (10 couples). Four couples went on to receive therapy by electroejaculation plus in vitro fertilization, along with six other couples (15 cycles total) with semen too poor for intrauterine insemination. RESULTS: One term pregnancy arose in the electroejaculation-intrauterine insemination group, and one term pregnancy plus one continuing pregnancy arose from two couples (three cycles) who underwent in vitro fertilization with conventional insemination after electroejaculation. Six couples (nine cycles) had embryos arising only from gamete micromanipulation transferred, and this yielded two term pregnancies, one spontaneous abortion, and a biochemical pregnancy. Two couples (three cycles) failed to achieve fertilization even with micromanipulation; however, donor-inseminated eggs gave rise to two term pregnancies and one continuing pregnancy in these patients. CONCLUSIONS: This report confirms the feasibility of in vitro fertilization in conjunction with electroejaculation and extends the therapy to incorporate gamete micromanipulation.

Adult↗