SELF-ELEVATING WHEELCHAIR

1306

reported; this is likely to lead to misleading conclusions. We report here a negative " series. "

Patients and Methods The ABO blood-groups of 3053 patients with histologically verified cancer at five different sites (lips, tongue, oesophagus, stomach, and breast) were determined in the Blood-Group The patients were classed Reference Laboratory, Oslo. to their of and their blood-groups were birth, according place compared with those of a series of healthy soldiers (Lerche 1940, Hartmann et al. 1941, Henriksen and Kvittingen 1950). Lerche (1940) and Henriksen and Kvittingen (1950) classed the soldiers according to place of residence at time of enlistment, and Hartmann et al. (1941) according to place of birth; but as the correlation between these was very high (Central Bureau of Statistics 1963) the three series were grouped (table l). In table n the patients with cancer of each site are classed according to place of birth. In table ill the blood-group

New Inventions SELF-ELEVATING WHEELCHAIR

PATIENTS with

arthritis of both the hips and knees much assistance in sitting down and in commonly require to themselves start walking. This difficulty may be positioning overcome by electrically powered devices; but these are expensive; and accordingly we have devised a simple adaption of severe

distributions observed are compared with the expected distributions. To obtain the " expected " figures we multiplied the blood-group incidence for each region by the relative representation of that region for the appropriate cancer site. The results were tested by the Z2 method. Significance was approached for one site-the lips, with p approximately 0-04-but since five comparisons were in progress,

be regarded as not significant. Our results do support any association between blood-group and cancer of any of these five sites.

this

must

not

REFERENCES Central Bureau of Statistics of Norway (1963) Personal communication. Hartmann, O., Hadland, K., Bjerkelund, C. J. (1941) Avh. norske Videns Akad. no. 5. Henriksen, S. Dick, Kvittingen, J. (1950) Acta path. microbiol. scand 27, 546. Lerche, C. (1940) Norsk Tidsskr. Milit Med. no. 5. Race, R. R., Sanger, Ruth (1962) Blood Groups in Man. Oxford. Roberts, J. A. Fraser (1959) Brit. med. Bull. 15, 129. Wiener, A. S. (1962) Lancet, i, 813.

wheelchair, which is cheap and highly effective. Beneath the chair, attached at one end to the foot-plate and at the other to the rear of the chair, are four springs (see fig. 1). The strength of these springs needs to be varied with the weight of the patient; for example, for a 90 lb. patient the total pull of the springs is 70 lb. The patient stands on the foot-plate (fig. 2) and then leans back, when the weight of her body forces the hinged seat of the chair to travel down and back in the plane parallel to the ground (fig. 3). Two small hooks hold the seat

a

down in Dosition, if necessarv, when the chair is beins wheeled To get out of the over rough ground. chair the patient moves her weight forward on to the front of the chair and the pull of the springs then elevates the seat, helping the patient to regain the upright

position. This principle may be applied to making toilet chairs, and has much increased the capacity for self-care of severely handicapped patients. We wish to thank the Director General of Health. New Zealand. for nermission to

publish. C. HISCOCK

Fig. 1.

Fig. 2.

I. C. ISDALE M.B., N.Z., Queen Elizabeth Hospital, Rotorua, New Zealand M.R.C.P., M.R.A.C.P.

Fig. 3.