GB2377157A

GB2377157A - Garment with pockets for holding monitoring devices

Info

Publication number: GB2377157A
Application number: GB0213502A
Authority: GB
Inventors: Stephen Jeffrey Davies
Original assignee: CEREBRA FOUNDATION FOR
Current assignee: CEREBRA FOUNDATION FOR
Priority date: 2001-06-15
Filing date: 2002-06-13
Publication date: 2003-01-08
Also published as: GB0213502D0; GB0114618D0

Abstract

A garment covering at least the lower limbs, e.g. an all-in-one body suit (10) has a plurality of pockets (18) for receiving one or more monitoring devices, such as twin axis electrogoniometers (22). Signals representative of measurements obtained from the monitoring devices (22) are transmitted via a wireless transmitter to a remote work station for storage and/or viewing or analysis in real time.

Description

Subject Physical Monitoring This invention relates to monitoring of physical subjects (typically human subjects) in relation to bio physical status and/or motion status of the subject, and more particularly, but not exclusively, to apparatus for use in long term monitoring of posture and gait in adults who have had total hip arthroplasty or similar surgical procedures performed on them, and children with a wide variety of neurological problems, such as cerebral palsy, epilepsy, attention deficit/hyperactivity disorders, etc, so as to allow diagnosis of conditions and measure effectiveness of treatments and other interventions; or for use in monitoring the physical condition or status of sporting personnel, or the like.

In the past, force platforms and camera (i. e. video surveillance) gait analysis systems have been used monitoring the posture and gait of patients.

In recent years, however, it has become more common to record and analyse motion of joints, such as hips and knees of a human subject, using flexible electrogoniometers and foot switches to evaluate the subject's posture and gait. Such flexible electrogoniometers generally comprise a central strain gauged strip surrounded by a spring with two end plates for attachment to the patient. The goniometers are light, flexible, planar devices and do not require a specific centre of rotation. They can therefore be placed over a joint without restricting motion.

Thus, in one known method, described in Clinical Biomechanics 1989 ; 4 : 68-72 (P. J. Rowe, A. C. Nichol, I. G. Kelly), four flexible electrogoniometers are taped or otherwise attached to the patient and used to measure flexion-extension angles of both hips and both knees. Foot switches are placed under the heel and toe of each foot to record the temporal parameters of gait and strain gauged, force measuring walking aids are available if required.

In the described method, during testing, the patient wears a special pair of Tubigrip tights, to the outside of which the electrogoniometers are attached using VelcroRTM or the like. Close fitting polypropylene strips are inserted into pockets running down the side of each limb segment of the tights, which strips stiffen the material, minimise fabric movement and resist

rotation of the plane of the material of the tights to provide a secure foundation to which the electrogoniometers can be attached.

The wires from the electrogoniometers, foot switches and walking aids are restrained using Velcro'patches sewn on to the tights, and these measuring instruments are connected via a long umbilical cable to computerised data recordal and control equipment located a certain distance from the patient.

The patient is asked to walk or otherwise move around and the flexion-extension angles of the hips and knees are determined and transmitted by the electrogoniometers to the recordal and control equipment where it can be displayed and analysed by a trained operative.

The system can be used to measure various gait parameters, including cycle symmetry, joint motion, walking velocity, cadence, cycle length, temporal patterns, and walking aid usage and, using eight electrogoniometers, it is possible to measure the flexion/extension and adduction/abduction angles of all the lower limb joints. The kinematic data thus obtained can then combined with standard body segment parameters (segment lengths, mass, centre of gravity) to provide a model of patient locomotion and Newton's laws of motion can be applied to calculate the gravitational and inertial forces acting on each segment so as to enable estimation of ground reaction and external joint force from the joint motion data.

However, there are a number of drawbacks associated with the above-described method and arrangement. The first of these is that, because the electrogoniometers are attached to the outside of the tights, they are susceptible to tampering with and removal by the patient, which is particularly disadvantageous in the case where the patient is an infant or child. Further, the long umbilical cable required to connect the measuring devices to the recordal and control equipment is large and cumbersome and, because it must usually be carried, it can result in limited and artificial movement of the patient. The requirement of a hard wired connection to remote data recordal equipment, in any event, means that the patient is tethered to the work station and an indoor laboratory or clinical environment, which is again particularly disadvantageous in the case of young patients.

In another known arrangement, the electrogoniometers may instead be connected to a portable data logger (which can be carried or worn by the patient). The data logger receives the measurement data from the electrogoniometers and stores it for the period during which the patient's movement is being monitored. The data logger can then be removed from the patient, and the complete set of data downloaded to the control equipment for display and analysis. This alleviates the need for a large and cumbersome umbilical cable between the patient and the work station, and allows the patient more freedom of movement. However, this arrangement does not enable the measurements to be analysed or even displayed in real time, thus substantially increasing the time required to perform the entire measurement and analysis process. Furthermore, if the measurements taken are, for whatever reason, insufficient, this will not be identified until the testing process is finished and the whole process would have to be repeated to obtain further measurements, which is obviously time consuming and inconvenient, as well as potentially causing unnecessary distress to the patient.

We have now devised an arrangement which overcomes the problems outlined above, and provides a method and apparatus which allows convenient long term monitoring of bio physical and/or motion status, such as posture and gait, of an adult, child or infant.

In accordance with a first aspect of the present invention, there is provided apparatus for use in monitoring a subject's physical condition, comprising a garment having at least two lower limb segments to be worn the subject, each of said lower limb segments comprising at least one pocket for receiving and retaining in the required position one or more monitoring devices, when the apparatus is in use.

Thus, the apparatus of the present invention provides an item of clothing in which monitoring devices can be partially or completely embedded during use, so that they are unobtrusive and effectively tamper-proof. It is preferred that the monitoring devices be completely enclosed to maximise the tamper-proofnature ofthe apparatus, although if the devices are only partially enclosed rapid interchange of sensors during experimental measurement is facilitated. The apparatus is particularly (but not exclusively) suited for use in monitoring a subject's mechanical movement, such as movement analysis in respect of subjects thought or known

to have a neurological disorder or condition, joint movement analysis for diagnosis of conditions such as RSI and the like, joint analysis for post-operative orthopaedic assessment, etc. as monitoring devices for this purpose are, by their very nature, required to be positioned on or over a subject's joint or other moving part, and it is therefore substantially more difficult to maintain such devices in the required position during testing of the subject than, for example, devices for use in ECG (electrocardiography) or EMG (electromyography) testing, which measure biopotential (i. e. electrical signals) within the subject's body. However, the garment of the first aspect of the present invention would be equally suitable for use in this and other types of monitoring using physiological signals obtained from a subject, such as electrocardiography or respiration measurement.

The first aspect of the present invention extends to a method of monitoring a subject's physical condition, comprising the steps of providing a garment as defined above, inserting one or more monitoring devices into at least one of the pockets provided in the garment, and obtaining output signals from the or each monitoring device.

The garment may be, for example, a pair of shorts (if only upper leg and hip measurements are required) or a pair of trousers (if measurements are required to be taken along the whole length of the lower limbs). However, in a preferred embodiment, the garment is an all-in-one suit extending from the subject's shoulder to their ankle, with openings being provided for the subject's arms. The suit may have sleeves if required.

The or each pocket may comprise an elongate channel provided on the outer or inner surface of the garment corresponding to the location on the subject at which one or more monitoring devices are required to be positioned, when the apparatus is in use. The or each channel is preferably open (or openable) at one end and closed at the other, the open end being for receiving the one or more monitoring devices. The open end is beneficially provided with closing means so that the monitoring devices can be completely enclosed by the pocket once it has been inserted therein. In one embodiment of the invention, individual pockets are provided to correspond with each location on the patient at which monitoring devices may be required to be positioned. However, in another embodiment, a single channel may be provided

along substantially the whole length of the garment (preferably one on each side of the garment) so that monitoring devices can be inserted at any point along the length of the channel. This facilitates the use of the garment for many different monitoring processes and varying sized subjects.

In a preferred embodiment, the pockets for receiving and retaining the monitoring devices also receive and retain (and partially or completely enclose) any cables associated with the devices, although additional pockets may be provided for this purpose.

The garment is beneficially at least partially made of a resiliently flexible material, such as LycraRTM, which is comfortable and helps to retain the monitoring devices against the subject's body, when in use. It has been discovered that a garment according to the invention does not significantly affect the posture and gait of a subject, such that measurements taken by monitoring devices embedded in the garment are not affected thereby.

In accordance with a second aspect of the present invention, there is provided apparatus for monitoring a subject's physical condition, the apparatus comprising one or more monitoring devices located in or on a subject's body, and at least one wireless transmitter for transmitting data from said one or more monitoring devices to a remote data storage and/or processing station for viewing or analysis in real-time.

Thus, the second aspect of the present invention provides apparatus for monitoring a subject's physical condition, in which a number of monitoring devices are fixed to the subject's body at various locations for measuring, for example, movement, and a wireless transmitter for transmitting the measurement data to a remote station for viewing an analysis as required. The telemetry system used in the second aspect of the present invention alleviates the need for the large and cumbersome umbilical cable providing a hard wired connection to the station, as required in the prior art arrangement described above. Again, the second aspect of the present invention is particularly suitable for mechanical motion analysis of the subject, because of the requirement for freedom of movement during measurement collection.

In the case that the measurements obtained by the monitoring devices is analogue in nature (as it would be in the case of mechanical movement monitoring devices, such as electrogoniometers and the like), the apparatus preferably includes an analogue-to-digital converter for converting the measured data into a digital format suitable for wireless transmission to the remote station.

The second aspect of the present invention extends to a method of monitoring a subject's physical condition, providing one or more monitoring devices in or on a subject's body for obtaining measurements relating to the subject's physical condition, converting, if necessary, said measurements into a format suitable for wireless transmission, and transmitting said converted data to a remote data storage and/or processing station for viewing or analysis in real-time. The telemetry unit may, for example, comprise a relay unit to relay the resultant data stream to a clinical work station for storage, analysis and visualisation. Data is available in real time, but may also be stored for analysis and modelling.

Both aspects of the present invention are especially suitable for movement analysis in children and infants, due to the tamper-proof manner in which the monitoring devices are positioned and held, and due to the lack of a large umbilical cable between the subject and a workstation.

In a preferred embodiment, the apparatus of the second aspect of the present invention is embedded in or attached to a garment according to the first aspect of the present invention.

Thus, the monitoring devices would be embedded in pockets corresponding to the location on the subject at which measurements are required to be taken. The transmitter (and A/D converter, if required) may be housed in a single unit to which all of the monitoring devices are connected, the unit either being held in another pocket on the garment, or hooked or otherwise held on the suit at a suitable location convenient to the subject.

The remote station may include some form of analysis capability for calculating various parameters therefrom and/or automatically analysing the measurements received from the monitoring devices to provide or offer a diagnosis and/or an indication as to any improvement or otherwise in the subject's physical condition and/or any suggested treatment or intervention and, possibly, the likelihood of success of any such treatment or intervention. Many gait

analysis software packages are currently available for analysing measurements received from mechanical movement sensors, such as electrogoniometers or the like.

In the case of both aspects of the present invention, the monitoring devices may comprise twin axis electrogoniometers.

An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1 is a side view of a subject wearing an all-in-one garment according to a first exemplary embodiment of the present invention; Figure 2 is a side view of a subject wearing the all-in-one garment of Figure 1, with a plurality of monitoring devices being retained in the pockets of the garment; Figure 3 is a schematic diagram illustrating the configuration of the monitoring devices retained in the all-in-one garment of Figure 2; and Figure 4 is a perspective view of an electrogoniometer suitable for use in a method of monitoring a subject's physical condition according to an exemplary embodiment of the present invention.

Referring to Figure 1 of the drawings, a garment according to the present invention comprises an all-in-one body suit 10 which extends from a subject's shoulder 12 to their ankles 14. An opening 16 is provided to accommodate the subj ect's arm (not shown), and elasticated stirrups 17 are provided at the bottom of each leg of the suit 10 to accommodate the subject's feet 20.

A plurality of elongate channel-like pockets 18 are provided on the outer surface of the suit 10, extending down the subject's side.

In use, referring to Figure 2 of the drawings, one or more monitoring devices, such as twin axis electrogoniometers 22, are placed in the pockets 18 over the joint required to be monitored, and the cables 24 for each of the electrogoniometers 22 also extend through the

pockets 18 as shown. The configuration of the electrogoniometers 22 and the associated cables can be seen more clearly in Figure 3 of the drawings. In the example shown, an electrogoniometer 22 is placed over each of the subject's hips, knees and ankles, and a foot switch 26 is placed under each of the subject's heels (to identify each time the subject places their heel to the ground during, for example, a walking exercise). In the illustrated example, separate pockets 18 are provided for each of the electrogoniometers 22, and an additional loop 30 is provided between two of the pockets to provide extra support for the cables 24 between the knee and hip electrogoniometers. However, in another, more preferred embodiment, a single elongate pocket may be provided which extends from a position close to the subject's ankle to a position at or adjacent the subject's waist for accommodating all of the electrogoniometers 22 and cables 24.

An example of an electrogoniometer 22 suitable for use in the present invention is illustrated in Figure 4 of the drawings. It comprises a central strain gauged strip 100 surrounded by a spring, with two end plates 102 for attachment to the patient. A cable 24 is provided for carrying analogue signals representative of the joint angle (based on the degree of bend in the central strip 100) to a receiving unit (such as a work station in the prior art) or an A/D converter and/or transmitter in the case of the present invention.

Analogue signals representative of joint angle measurements are transmitted to an analogue-todigital converter (not shown) to be converted into digital format, and the resultant digital signals are transmitted by a wireless transmitter (not shown) to a remote workstation (not shown) for storage and/or viewing or analysis in real time. A posture and gait analysis software package may be run on the workstation which receives the data from the electrogoniometers, and, for example, calculates various parameters such as cadence, step length/height ratios, etc. , offers a diagnosis, suggests a mode of treatment or intervention and possibly its likelihood of success, etc.

An embodiment of the present invention has been described above by way of example only and it will be apparent to a person skilled in the art that modifications and variations can be made to the described embodiments without departing from the scope of the invention as defined in the appended claims.

Claims

Claims 1. Apparatus for use in monitoring a subject's physical condition, comprising a garment having at least two lower limb segments to be worn by a subject, each of said lower limb segments comprising at least one pocket for receiving and retaining in the required position one or more monitoring devices, when the apparatus is in use.
2. Apparatus according to claim 1, wherein the garment is a pair of shorts or a pair of trousers.
3. Apparatus according to claim 1, wherein the garment is an all-in-one suit extending from a subject's shoulder to their ankle, with openings being provided for the subject's arms.
4. Apparatus according to claim 1, wherein the suit has sleeves.
5. Apparatus according to any one of claims 1 to 4, wherein the or each pocket comprises an elongate channel provided on the outer or inner surface of the garment corresponding to the location on the subject at which one or more monitoring devices are required to be positioned, when the apparatus is in use.
6. Apparatus according to claim 5, wherein the or each channel is open (or openable) at one or both ends, the open end (s) being for receiving the one or more monitoring devices.
7. Apparatus according to claim 6, wherein the open ends is or are beneficially provided with closing means so that the monitoring devices can be completely enclosed by the pocket once it has been inserted therein.

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8. Apparatus according to claim 1, wherein individual pockets are provided to correspond with each location on the subject which monitoring devices may be required to be positioned.
9. Apparatus according to claim 1, wherein a single channel is provided along substantially the whole length of the garment (preferably one on each side of the garment) so that monitoring devices can be inserted at any point along the length of the channel.
10. Apparatus according to claim 1, wherein the pocket for receiving and retaining the monitoring devices also receive and retain (and partially or completely enclose) any cables associated with the devices.
11. Apparatus according to any one of the preceding claims, wherein the garment is at least partially made of a resiliently flexible material, such as Lycra RTM
12. A method of monitoring a subject's physical condition, comprising the steps of providing a garment according to any one of claims 1 to 11, inserting one or more monitoring devices into at least one of the pockets provided in the garment, and obtaining output signals from the or each monitoring device.
13. Apparatus for monitoring a subject's physical condition, the apparatus comprising one or more monitoring devices located in or on a subject's body, and at least one wireless transmitter for transmitting data from said one or more monitoring devices to a remote data storage and/or processing station for viewing or analysis in real-time.
14. Apparatus according to claim 13, including an analogue-to-digital converter for converting the data obtained from said monitoring devices into a digital format suitable for wireless transmission to the remote station.

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15. Apparatus for monitoring a subject's physical condition substantially as herein described with reference to the accompanying drawings.
16. A method of monitoring a subject's physical condition, providing one or more monitoring devices in or on a subject's body for obtaining measurements relating to the subject's physical condition, converting, if necessary, said measurements into a format suitable for wireless transmission, and transmitting said converted data into a remote data storage and/or processing station for viewing or analysis in real-time.

The telemetry unit may, for example, comprise a relay unit to relay the resultant data stream into a clinical work station for storage, analysis and visualisation. Data is available in real time, but may also be stored for analysis and modelling.
17. A method of monitoring a subject's physical condition, substantially as herein described with reference to the accompanying drawings.