Computer-controlled manipulator/display system for human-movement studies.

BACKGROUND: Laparoscopic surgery may be kinder to the patient, but it is more demanding on the surgeon. Fixed trocar positions often require the surgeon to work with instruments at awkward angles to their body. We studied the effect of horizontal and vertical laparoscopic instrument working angle on the surgeon's thumb, forearm, and shoulder muscle work. METHODS: Electronyographic (EMG) signals were collected from the thenar compartment (TH), flexor digitorum superficialis (FDS), and deltoid (DEL) muscles of the dominant arm of eighth surgeons while they were closing a standard pistol-grip disposable laparoscopic grasper against a fixed resistance of 3 N. With the aid of a special testing bench, the instruments' position was randomly changed among 15 degrees, 45 degrees, and 75 degrees of horizontal angulation relative to the surgeons' sagital plane, and 15 degrees, 45 degrees, and 75 degrees degrees of vertical angulation relative to a horizontal plane. EMG signals were rectified and smoothed using analogue circuitry and digitally sampled at l0 Hz using a National Instruments DAQCard-700 connected to a Macintosh PowerBook 5300c running LabVIEW software. Statistical analysis was carried out by analysis of variance (ANOVA). RESULTS: The effects of vertical and horizontal working angles on the muscle effort were as follows: TH (horizontal, N.S.; vertical, N.S.), FDS (horizontal, p 45 degrees to the surgeon's sagital plane significantly increases the workload of the flexor digitorium superficialis and deltoid muscles. The deltoid muscle is also adversely affected by vertical angulation of the instrument. The instrument working angle has no effect on the thenar muscles. Whenever possible, laparoscopic surgeons should strive to place their instruments and trocars so as to minimize extreme horizontal or vertical displacement of their hands away from a resting position of comfort.

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PubMed2001

[Arm morbidity after axillary dissection for breast cancer].

INTRODUCTION: Axillary dissection for breast cancer is known to leave the patient with arm morbidity. The aim of this study was to describe the occurrence of lymphoedema, subjective swelling, abnormal sensations, and pain in a consecutive group of patients operated for breast cancer. METHODS: From April to October 1992, 140 consecutive women underwent an operation for breast cancer with axillary dissection at levels one and two. Patients with bilateral breast cancer or radiotherapy towards the axilla were excluded. The surviving 124 patients were invited to an investigation on arm morbidity and a questionnaire on subjective complaints was sent to them. Medical records and pathology reports were reviewed. Ninety-five patients (77%) were examined. Oedema of the arm was assessed by circumference measurements at three points. RESULTS: Objective oedema was found in six patients (6%). Subjective swelling was reported by 24 women (25%). Of these, 14 women reported slight swelling, seven had moderate swelling, and three had severe swelling of the arm. Pain within the three months preceding the examination was reported by 31 (33%). Analgesics were taken by 13 women (14%), of whom five used analgesics daily. Abnormal sensations in the ipsilateral arm was reported by 62 (65%). Young patients in the low risk group, with removal of more than ten lymph nodes, suffered a higher degree of arm morbidity. CONCLUSIONS: The only modifiable risk factor identified is the number of lymph nodes removed in axillary dissection. Other methods of staging could probably lessen arm morbidity.

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