A Pockels cell enabled heterodyne phase contrast imaging diagnostic for detection of ion cyclotron emission

This work describes a novel optical heterodyne detection scheme that significantly extends the frequency response of the phase contrast imaging method to detect electron density fluctuations in tens of megahertz frequency range. The system employs a variable frequency electro-optic modulator to allow operation at any frequency in the range 10-40 MHz without the need to realign the system. The frequency coverage of the system makes it suitable to measure the radial structure of the electron density component of ion cyclotron emission on devices having confining magnetic field of a few tesla, thus extending the purely temporal measurements provided so far by magnetic probes.

Review of 47 laparoscopic appendectomies

STUDY OBJECTIVE

To assess the indications, technique, complications, and outcome of endoscopic appendectomies.

DESIGN

Retrospective study with a follow-up of 2 years.

SETTING

A gynecologic surgical center in Hamburg, Germany.

PATIENTS

Forty-seven women who underwent laparoscopic appendectomy.

INTERVENTIONS

Appendectomies were performed under general anesthesia with bipolar coagulation, loop-ligation, and transection.

MEASUREMENTS AND MAIN RESULTS

Forty-seven patients have been followed for 2 years. Thirty laparoscopic appendectomies (LA) were incidental and 17 elective. The majority of LA were performed because of pain symptoms. More than 50% of the patients reported complete pain relief after LA. The average duration of surgery was 47 minutes. The average hospital stay was 66 hours. Use of analgesics was low; 19 women required no analgesia. A febrile reaction was registered in 6%. No wound infection occurred. Two serious complications were noted: one acute peritonitis after 4 days, and one stump abscess after 4 weeks. Both patients recovered uneventfully.

CONCLUSIONS

Laparoscopic appendectomy is safe surgery if the described technique is followed. The complication rate is low, conversion rate is zero, and late results underline successful treatment of pain.