We claim:
1. An apparatus for monitoring the movements of a person on a bed or the changes therein, such movements including epileptic convulsive seizures, other deviant movements, tremors, respiration, mechanical cardiac functions, or any other motorics of the person under examination, without attaching a pick-up means directly to the person, said apparatus comprising:
(a) an active layer;
(b) an antenna means;
(c) an amplifying means connected to said antenna means; and
(d) a monitoring means connected to said amplifying means;
wherein said active layer comprises at least two mutually contacting courses of insulating material having different dielectric constants adapted so that an electrical charge is generated in said layer by relative movement between said contacting courses; and wherein said antenna means is adapted to detect electrical charge generated within said active layer, resulting in an electrical signal being conveyed from said antenna means to the amplifying means and amplified therewith, said amplified signal being conveyed to the monitoring means and converted into a visual, auditory or mechanical signal therewith.
2. An apparatus according to claim 1 wherein the antenna means is adapted to be placed under a mattress and comprises two conductive elements spaced apart from each other.
3. An apparatus according to claim 2 wherein the elements are plates.
4. An apparatus according to claim 2 wherein the elements are nets.
5. An apparatus according to claim 2 wherein the elements are rods.
6. An apparatus according to claim 2 wherein the elements comprise metal films affixed on the opposite surfaces of an insulating layer.
7. Apparatus according to claim 2 characterized in that the active layer and the antenna means are resilient and can be folded or rolled up.
8. Apparatus according to claim 1 wherein the active layer and the antenna means are disposed one upon the other to constitute a recording mattress.
9. Apparatus according to claim 8, characterized in that the recording mattress is located within a protective shield having an inner surface and an outer surface, of which the inner surface consists of an electrically insulating material and the outer surface consists of an electrically conductive material, and said protective shield is connected to a ground terminal of the amplifier means.
10. Apparatus according to claim 9, characterized in that the active layer comprises resilient insulating courses and the antenna means comprises two conductive plates, and said active layer constitutes an insulator between one antenna plate and the protective shield to form a capacitance means.
11. Apparatus according to claim 1, characterized in that one of the courses is a material with airfilled blisters which rest against the other course.
Other info:Inventors:
Alihanka, Jukka (Littoinen, FI)
Vaahtoranta, Kaarle (Turku, FI)
Bjorkqvist, Stig-eyrik (Turku, FI)
Application Number:
06/128835
Filing Date: 1980-03-10
Publication_date: 1982-03-23
Assignee:
INSTRUMENTARIUM OY
Primary Class(es):
600/484
600/595, 340/562, 361/283.100, 600/535
Other Classes:
A61B5/113;
A61B5/11; A61B5/10
US Patent Ref:
| 3572316 | March, 1971 | Vogelman et al. | 128/671 | |
| 3821491 | June, 1974 | Whetstone et al. | 179/111E | |
| 3875481 | April, 1975 | Miller et al. | 361/283 | CAPACITIVE WEIGHING MAT |
| 3926177 | December, 1975 | Handway et al. | 128/722 | Activity and respiration monitor |
| 3991746 | November, 1976 | Hanna | 128/722 | Patient monitoring system and method |
| 3996922 | December, 1976 | Basham | 128/722 | Flexible force responsive transducer |
| 4152748 | May, 1979 | Arkans | 361/283 | Multiple transducer |
Other Refs:
Primary Examiner:
Michell, Robert W.
Assistant Examiner:
Hanley, John C.
Attorney:
Keil & Witherspoon