Studies in health technology and informatics, 2012
The outcomes of brace treatment for scoliosis depend on how the brace is used. Simply prescribing... more The outcomes of brace treatment for scoliosis depend on how the brace is used. Simply prescribing a brace does not mean it will be worn properly. A smart brace has been developed to control the brace wear tightness with the expectation that appropriately worn braces will improve outcomes. Twelve brace candidates (10F; 2M) agreed to participate into this study and were randomly divided into 2 groups. The smart brace group used the smart brace for the first year, and then wore the standard brace for the following year. The standard rigid brace group wore their TLSO for 2 years. Both groups were followed for 3 years after they finished the brace treatment. The smart brace group showed better quality of brace wear, wearing their brace at the prescribed tightness level a higher proportion of time than the standard brace group. All subjects in the smart brace group had successful outcomes, Cobb angle changed less than 5°, whereas 2/6 subjects in the standard brace group had unsuccessful bracing. One had 7° increment and 1 underwent surgery. The smart brace group also reported that the smart brace was more comfortable to wear than the standard rigid brace.
Scoliosis is a deformity characterized by lateral curvature of the spine and accompanied by axial... more Scoliosis is a deformity characterized by lateral curvature of the spine and accompanied by axial rotation of the vertebrae; it often causes varying degrees of trunk deformity. Research has indicated that topographic techniques can be used to describe the disorder and monitor its progression. A video image acquisition system has been designed which reduces the time required to quantify topographic details of the trunk and aids in the diagnosis, monitoring and research of scoliosis. This system integrates the capability of large, expensive grey-scale image acquisition equipment into a small, low-cost diagnostic imaging tool using current technologies and design techniques. The video digitizer accepts a standard NTSC monochromatic video signal as input and the unit is connected to a computer via an IEEE-488 bus from which the ditigizer is controlled. The digitizer samples the video signal in real time using a high-speed flash converter controlled by an application-specific integrated circuit; the digital samples are stored in memory until the host computer requests that the information be transferred.
Studies in health technology and informatics, 2002
The Cobb angle has been the most commonly used method in measuring the severity of scoliosis and ... more The Cobb angle has been the most commonly used method in measuring the severity of scoliosis and its progression. However, in recent years a number of researchers have chosen to monitor scoliosis by examining the severity of the surface deformity resulting from the scoliosis. Each of these approaches has been limited by errors introduced in manual location of landmarks. Scoliosis results in an asymmetry of the back. It would be very desirable to have a computer-based method of measuring this asymmetry. This paper investigates the use of wavelets and the concept of local energy to measure asymmetry associated with scoliosis. The local energy model uses wavelet theory to obtain information about shading and boundaries of objects in an image. Edges and sharp discontinuities are areas of high local energy in an image. Features such as scapular prominence, shoulder edges, waist creases and other anomalies that contribute to the scoliotic back asymmetry have high local energy. A prelimina...
Studies in health technology and informatics, 2002
There are a number of forces applied during scoliosis surgery, the magnitude and direction of whi... more There are a number of forces applied during scoliosis surgery, the magnitude and direction of which remains unknown. There is little literature concerning the in vivo distribution of forces along the spine. Computer modelling (ANSYS) was used to investigate the possibility of using an instrumented hook to intra-operatively measure the antero-posterior and distraction/compression forces applied by the surgeon during corrective scoliosis surgery. Three hook designs were evaluated based on specific design criteria. ANSYS provided the preliminary analysis to determine the strain distribution in these hooks. One design, the "membrane" design, was selected and a prototype was manufactured. Preliminary tests demonstrate that this prototype will be able to differentiate between the four major forces applied during the surgical correction.
2006 International Conference of the IEEE Engineering in Medicine and Biology Society, 2006
Osteoarthritis is a debilitating joint disease where the surface of articular cartilage degrades ... more Osteoarthritis is a debilitating joint disease where the surface of articular cartilage degrades and is unable to repair itself through natural processes. Controlling the migration of transplanted chondrocytes to the defective cartilage non-invasively could be a novel treatment for osteoarthritis. Our research group has performed an in-vitro investigation into the response of cultured human chondrocytes to pulsed electromagnetic fields (PEMF). Development of a treatment for osteoarthritis patients will require the use of a programmable waveform generator to generate the PEMF. This paper discusses the design and testing of a programmable ramp waveform generator for such purpose. When this ramp waveform generator is connected to the PEMF coil driver circuitry, it will be able to produce linearly ramping magnetic fields ranging in strength from 0.5 mT to 4.5 mT. It also has an attainable pulse width ranging from 6 ms to 100 ms, with a selectable duty cycle from 1% to 99%
Medical & Biological Engineering & Computing, 2002
An electronically instrumented rod rotator has been developed to monitor forces and moments appli... more An electronically instrumented rod rotator has been developed to monitor forces and moments applied by surgeons during the derotation manoeuver to correct spinal curvature. This instrumented rod rotator consisted of an inclinometer and two pairs of strain gauges, with all the support circuitry. The strain gauge and the inclinometer data were sampled with a data-acquisition system, and the results were displayed in real time. The device was calibrated in the laboratory and used on seven subjects. The precision of the load measurement of this device was + 5 N in the range of 5-65 IV. The distance between the middle of the rod rotator handle to the rod position was 0.21m. The maximum loads applied by the surgeon during seven surgeries were from 22 to 57N, with a torque (force x distance) from 4.6 to 12 Nm.
Medical & Biological Engineering & Computing, 2009
In order to reduce the observer variability in radiographic scoliosis assessment, a computer-aide... more In order to reduce the observer variability in radiographic scoliosis assessment, a computer-aided system was developed. The system semi-automatically measured the Cobb angle and vertebral rotation on posteroanterior radiographs based on Hough transform and snake model, respectively. Both algorithms were integrated with the shape priors to improve the performance. The system was tested twice by each of three observers. The intraobserver and interobserver reliability analyses resulted in the intraclass correlation coefficients higher than 0.9 and 0.8 for Cobb measurement on 70 radiographs and rotation measurement on 156 vertebrae, respectively. Both the Cobb and rotation measurements resulted in the average intraobserver and interobserver errors less than 2 degrees and 3 degrees , respectively. There were no significant differences in the measurement variability between groups of curve location, curve magnitude, observer experience, and vertebra location. Compared with the documented results, measurement variability is reduced by using the developed system. This system can help orthopedic surgeons assess scoliosis more reliably.
IEEE Transactions on Instrumentation and Measurement, 2007
This paper describes a low-cost imaging system that is used to quantify the torso deformity that ... more This paper describes a low-cost imaging system that is used to quantify the torso deformity that is associated with scoliosis. The system consists of image-capture and imageanalysis components. The image-capture component obtains fulltorso scans using a rotating positioning platform and one or two surface digitizers. The image-analysis component assesses torso shape. Results of system calibration and error analysis (accuracy of reproduction based on tests on a calibration box, a plaster cast, and a human subject) show that the system can be used to quantify the deformity associated with scoliosis.
Repetitive pointing movements to remembered proprioceptive targets were investigated to determine... more Repetitive pointing movements to remembered proprioceptive targets were investigated to determine whether dynamic proprioception could be used to modify the initial sensorimotor conditions associated with an active definition of the target position. Twelve blindfolded subjects used proprioception to reproduce a self-selected target position as accurately as possible. Ten repetitions for each limb were completed using overhead and scapular plane pointing tasks. A 3D optical tracking system determined hand trajectory start and endpoint positions for each repetition. These positions quantified three-dimensional pointing errors relative to the target position and the initial and preceding movement repetitions, as well as changes in movement direction and extent. Target position and cumulative start position errors were significantly greater than the corresponding preceding movement (inter-repetition) errors, and increased as the trial progressed. In contrast, hand trajectory start and endpoint inter-repetition errors decreased significantly with repeated task performance, as did movement extent, although it was consistently underestimated for each repetition. Pointing direction remained constant, except for the angle of elevation for scapular plane pointing,
The ability of subjects with multidirectional shoulder instability to use proprioception to compl... more The ability of subjects with multidirectional shoulder instability to use proprioception to complete a series of upper limb repositioning tasks was investigated. Twelve subjects with multidirectional instability and 12 control subjects were blindfolded and instructed to use proprioception to reproduce a self-selected target position as accurately as possible. Subjects completed 10 repetitions for each limb using three distinct upper limb movements: overhead reaching, scapular plane pointing, and humeral external rotation with abduction. A three-dimensional video motion analysis system tracked limb position and determined spatial hand position error. Subjects with multidirectional shoulder instability showed significantly greater hand position error than control subjects. No hand position error differences were found between the symptomatic and the asymptomatic limbs of subjects in the instability group. Interrepetition error for subjects in both groups improved significantly during the first three movement cycles. These results suggest that after movement initiation, dynamic proprioception was a factor in improving hand position accuracy in both groups, but to a lesser degree in subjects with multidirectional instability. Consequently, subjects with multidirectional instability may have a reduced capacity to use proprioception to refine and control the motor output of the upper limb.
BackgroundPatients with depression and/or anxiety are commonly seen in inpatient geriatric settin... more BackgroundPatients with depression and/or anxiety are commonly seen in inpatient geriatric settings. Both disorders are associated with an increased risk of cognitive impairments, notably in executive functioning. Transcranial direct current stimulation (tDCS), a type of non-invasive brain stimulation, involves the administration of a low-dose electrical current to induce neuromodulation, which ultimately may act on downstream cognitive processing.ObjectiveThe purpose of this study was to determine the effects of tDCS on executive functioning in geriatric inpatients with symptoms of depression and/or anxiety.DesignPilot Randomized Controlled Trial.SettingSpecialized geriatric wards in a tertiary rehabilitation hospital.MethodsThirty older-aged adults were recruited, of which twenty completed ten-to-fifteen sessions of 1.5 mA anodal or sham tDCS over the left dorsolateral prefrontal cortex. Cognitive assessments were administered at baseline and following the tDCS protocol; analyses ...
Studies in health technology and informatics, 2002
The goal of this pilot study was to explore the relationship between pelvic obliquity and patient... more The goal of this pilot study was to explore the relationship between pelvic obliquity and patient pain, sitting tolerance, pressure sores, and function. Five neuromuscular patients who underwent spinal surgery 6-26 weeks prior to assessment took part in this on-going study (4F; 1M); age at surgery (14.6 +/- 2.6 years). Pelvic obliquity was measured from pre- and post-operative anterior-posterior radiographs. A force-sensing pad with a grid of sensors was placed on a flat surface and the weight distribution pattern was recorded. The pressures were divided into left and right sides and peak levels were noted on each side. The parents or caregivers completed a questionnaire on their child's pain, sitting tolerance, pressure sores, and functional abilities. Pelvic obliquity was reduced after surgery by approximately 50% depending on the method used to assess pelvic obliquity. The major curve was reduced from 64 degrees(10 degrees) to 39 degrees (10 degrees). Post operatively, the average pressure (left/right side) ranged from 1.2 to 2.0 (average 1.6). The peak pressure ratio ranged from 1.1 to 1.9 (average 1.4). The ratio of left/right pressure correlated with improvement in pelvic obliquity (r2=0.9). Pain was moderate/severe in the 2 patients with the least correction as measured with the Cobb angle from surgery; both improved following surgery. Two patients suffered pressure sores pre-operatively and one post-operatively. Only 3/5 felt sitting endurance had increased. All parents felt their child sat straighter after surgery. The outcome measures of pain, pressure sores, sitting tolerance, and function were not well related to the amount of pelvic obliquity. More candidates and a longer follow-up may shed light on the many relationships.
Studies in health technology and informatics, 2002
Kyphosis is an excessive rounding of the upper spine. Its treatment depends upon the severity, th... more Kyphosis is an excessive rounding of the upper spine. Its treatment depends upon the severity, the age of the patient and the levels of the spine that are affected. Early diagnosis is a key to providing optimal treatment. In a skeletally immature patient, an exercise program or bracing is the most commonly used treatment. However, the compliance of bracing for adolescents is poor and exercise training is labor intensive. The purpose of this study is to determine whether a Spine-Straight device can help patients to correct their kyphosis themselves and there by reduce back pain without the biomechanical support of a brace. The Spine-Straight device consists of an accelerometer and a microcomputer unit. The accelerometer is used to measure the kyphotic angle and the microcomputer unit controls a pager vibrator to alert patients when their posture exceeds personalized thresholds. The system was tested in the laboratory before used by subjects. The results were compared to back data obtained from a laser scanner imaging system. The maximum angle deviation between the laser scanner and the Spine-Straight device was 1.5 degrees. Two volunteers tested the systems for 2 days. The accelerometer was placed at the T3 location and the microcomputer unit was carried during daily activities. The angle measurement was recorded at 1 minute intervals during daily activity over a period of 2 days. The preliminary trials demonstrate subjects can improve their posture when feedback signals were provided.
The PVD Bio-Thesiometer was tested as a tool for measuring vibratory thresholds and for detecting... more The PVD Bio-Thesiometer was tested as a tool for measuring vibratory thresholds and for detecting possible differences in these thresholds between adolescents who have idiopathic scoliosis and those who do not. It was found to be limited by low reliability and large errors in measurement, with the metatarsophalangeal joint being the only reliable site for measurement. The vibratory thresholds at this site were significantly higher in the fourteen subjects who had scoliosis than in the twenty-two control subjects. No significant asymmetry in vibratory thresholds was found between the concave and convex or the right and left sides in either the scoliotic or the control group. Because there was no significant difference between the readings from the concave and convex sides, it is unlikely that a lesion of the posterior column is responsible for idiopathic scoliosis. If there is a difference, then the PVD Bio-Thesiometer is not sufficiently reliable to detect it.
In order to study a physiotherapeutic approach to idiopathic scoliosis treatment a posture monito... more In order to study a physiotherapeutic approach to idiopathic scoliosis treatment a posture monitoring system is being built. The system is a small, lightweight, fully portable system capable of monitoring and providing feedback to a patient regarding their posture. Using the combination of accelerometer and electromagnetic technology, distance and angle measurements can be obtained for receivers placed strategically on the patient's back. This data is recorded for further analysis of the patient's progress and to provide immediate feedback to the patient on the status of their posture. Preliminary testing has shown that angular changes of one degree can be detected by the system and that the speed of the electromagnetic field detection has been increased ten times greater than the previous architecture.
The aim of this study was to determine the long-term changes in spine and trunk alignment in pati... more The aim of this study was to determine the long-term changes in spine and trunk alignment in patients who have undergone scoliosis surgery. Twenty-three (16F; 7M; at age of surgery 15.7 +/- 4.9 years) patients with adolescent idiopathic scoliosis agreed to participate and had posterior-anterior radiographs and surface topography prior to derotation surgery, within 6 months of surgery, at 2 years post-operatively and 5-10 years (mean follow-up period 6.11 +/- 1.6 years) after surgery. Cobb angles, surface trunk rotations, and cosmetic scores were measured at each visit. A questionnaire assessed back appearance and pain at the 5-10 year follow-up. The results of the questionnaire were compared to 25 patients with idiopathic scoliosis who had recently undergone surgery. A paired two-tailed Student's t-test with p=0.05 was used to compare the deformity between visits. The Cobb angle and cosmetic score improved after surgery while the change in trunk rotation was insignificant (p=0.37). Between the two-year and 5-10 year review, the Cobb angle, cosmetic score, and surface trunk rotation significantly increased. Self-perception of appearance and pain were similar to the control group. Surgical correction of scoliosis is not completely maintained during adulthood although the radiographic and surface deterioration does not appear to be clinically significant.
To determine the reliability of a prognostic curve progression model and the role of the quantity... more To determine the reliability of a prognostic curve progression model and the role of the quantity and quality of brace wear for adolescent idiopathic scoliosis (AIS) brace treatment. To develop a curve progression model for full-time AIS brace treatment, 20 AIS subjects (Group 1) prescribed full-time thoracolumbar sacral orthosis (TLSO) were monitored and followed for 2 years beyond maturity. The developed curve progression model was: curve progression (in degrees) = 33 + 0.11 × Peterson risk (%) - 0.07 in-brace correction (%) - 0.45 × quality (%) - 0.48 × quantity (%) + 0.0062 × quantity × quality. To validate the model, 40 new (test) subjects (Group 2) who met the same inclusion criteria and used the same type of monitors, were monitored and followed for 2 years after bracing. For the 40 test subjects (Group 2), the average in-brace correction was 40 ± 22 %. The average quantity and quality of the brace wear were 56 ± 19 and 55 ± 17 %, respectively. Twelve subjects (30 %) progressed of which 10 subjects (25 %) required surgery and 28 subjects (70 %) showed no progression. The accuracy of the model to determine which patients would progress was 88 % (35/40) which was better than the Peterson's risk model (68 %; 26/40) alone. Patients who had the combined quantity times the quality over a threshold 43 % had a success treatment rate of 95 %. This study showed the prognostic model of brace treatment outcome on AIS patients treated with full-time TLSO was reliable. Both the quantity and quality of the brace wear were important factors in achieving successful brace treatment.
2006 International Conference of the IEEE Engineering in Medicine and Biology Society, 2006
Many of the aches and pains of adults are the result not of injuries, but of the long-term effect... more Many of the aches and pains of adults are the result not of injuries, but of the long-term effects of distortions in posture or alignment. Postural kyphosis in adolescence may be one of the effects of poor standing and sitting habits. Kyphosis is an excessive rounding of the upper spine. A smart garment that can monitor and provide vibration feedback to children has been developed to investigate an alternative treatment possibility. Laboratory tests verified that the accuracy of the system was +/-2 degrees within the full 180 degrees range. A clinical trial has been conducted and it showed that the system can aid subjects to improve by 20% the proportion of time in a more balanced posture. The long term effect is still under investigation.
IMTC/99. Proceedings of the 16th IEEE Instrumentation and Measurement Technology Conference (Cat. No.99CH36309)
ABSTRACT A battery-powered posture measurement system has been developed to monitor the topograph... more ABSTRACT A battery-powered posture measurement system has been developed to monitor the topographical features of a scoliotic trunk. The system consists of an electromagnetic measurement system and a microcomputer data acquisition system. The polar coordinates of up to 8 receivers relative to the transmitter can be determined. Laboratory tests showed that the maximum distance error was 0.5 cm and the maximum angle error was 5 degrees in the range of 30 to 47 cm. This system is applied to help adolescents who have scoliosis attain a more balanced posture with the use of feedback preliminary clinical trials were done and showed that the system was able to detect the postural changes
Studies in health technology and informatics, 2012
The outcomes of brace treatment for scoliosis depend on how the brace is used. Simply prescribing... more The outcomes of brace treatment for scoliosis depend on how the brace is used. Simply prescribing a brace does not mean it will be worn properly. A smart brace has been developed to control the brace wear tightness with the expectation that appropriately worn braces will improve outcomes. Twelve brace candidates (10F; 2M) agreed to participate into this study and were randomly divided into 2 groups. The smart brace group used the smart brace for the first year, and then wore the standard brace for the following year. The standard rigid brace group wore their TLSO for 2 years. Both groups were followed for 3 years after they finished the brace treatment. The smart brace group showed better quality of brace wear, wearing their brace at the prescribed tightness level a higher proportion of time than the standard brace group. All subjects in the smart brace group had successful outcomes, Cobb angle changed less than 5°, whereas 2/6 subjects in the standard brace group had unsuccessful bracing. One had 7° increment and 1 underwent surgery. The smart brace group also reported that the smart brace was more comfortable to wear than the standard rigid brace.
Scoliosis is a deformity characterized by lateral curvature of the spine and accompanied by axial... more Scoliosis is a deformity characterized by lateral curvature of the spine and accompanied by axial rotation of the vertebrae; it often causes varying degrees of trunk deformity. Research has indicated that topographic techniques can be used to describe the disorder and monitor its progression. A video image acquisition system has been designed which reduces the time required to quantify topographic details of the trunk and aids in the diagnosis, monitoring and research of scoliosis. This system integrates the capability of large, expensive grey-scale image acquisition equipment into a small, low-cost diagnostic imaging tool using current technologies and design techniques. The video digitizer accepts a standard NTSC monochromatic video signal as input and the unit is connected to a computer via an IEEE-488 bus from which the ditigizer is controlled. The digitizer samples the video signal in real time using a high-speed flash converter controlled by an application-specific integrated circuit; the digital samples are stored in memory until the host computer requests that the information be transferred.
Studies in health technology and informatics, 2002
The Cobb angle has been the most commonly used method in measuring the severity of scoliosis and ... more The Cobb angle has been the most commonly used method in measuring the severity of scoliosis and its progression. However, in recent years a number of researchers have chosen to monitor scoliosis by examining the severity of the surface deformity resulting from the scoliosis. Each of these approaches has been limited by errors introduced in manual location of landmarks. Scoliosis results in an asymmetry of the back. It would be very desirable to have a computer-based method of measuring this asymmetry. This paper investigates the use of wavelets and the concept of local energy to measure asymmetry associated with scoliosis. The local energy model uses wavelet theory to obtain information about shading and boundaries of objects in an image. Edges and sharp discontinuities are areas of high local energy in an image. Features such as scapular prominence, shoulder edges, waist creases and other anomalies that contribute to the scoliotic back asymmetry have high local energy. A prelimina...
Studies in health technology and informatics, 2002
There are a number of forces applied during scoliosis surgery, the magnitude and direction of whi... more There are a number of forces applied during scoliosis surgery, the magnitude and direction of which remains unknown. There is little literature concerning the in vivo distribution of forces along the spine. Computer modelling (ANSYS) was used to investigate the possibility of using an instrumented hook to intra-operatively measure the antero-posterior and distraction/compression forces applied by the surgeon during corrective scoliosis surgery. Three hook designs were evaluated based on specific design criteria. ANSYS provided the preliminary analysis to determine the strain distribution in these hooks. One design, the "membrane" design, was selected and a prototype was manufactured. Preliminary tests demonstrate that this prototype will be able to differentiate between the four major forces applied during the surgical correction.
2006 International Conference of the IEEE Engineering in Medicine and Biology Society, 2006
Osteoarthritis is a debilitating joint disease where the surface of articular cartilage degrades ... more Osteoarthritis is a debilitating joint disease where the surface of articular cartilage degrades and is unable to repair itself through natural processes. Controlling the migration of transplanted chondrocytes to the defective cartilage non-invasively could be a novel treatment for osteoarthritis. Our research group has performed an in-vitro investigation into the response of cultured human chondrocytes to pulsed electromagnetic fields (PEMF). Development of a treatment for osteoarthritis patients will require the use of a programmable waveform generator to generate the PEMF. This paper discusses the design and testing of a programmable ramp waveform generator for such purpose. When this ramp waveform generator is connected to the PEMF coil driver circuitry, it will be able to produce linearly ramping magnetic fields ranging in strength from 0.5 mT to 4.5 mT. It also has an attainable pulse width ranging from 6 ms to 100 ms, with a selectable duty cycle from 1% to 99%
Medical & Biological Engineering & Computing, 2002
An electronically instrumented rod rotator has been developed to monitor forces and moments appli... more An electronically instrumented rod rotator has been developed to monitor forces and moments applied by surgeons during the derotation manoeuver to correct spinal curvature. This instrumented rod rotator consisted of an inclinometer and two pairs of strain gauges, with all the support circuitry. The strain gauge and the inclinometer data were sampled with a data-acquisition system, and the results were displayed in real time. The device was calibrated in the laboratory and used on seven subjects. The precision of the load measurement of this device was + 5 N in the range of 5-65 IV. The distance between the middle of the rod rotator handle to the rod position was 0.21m. The maximum loads applied by the surgeon during seven surgeries were from 22 to 57N, with a torque (force x distance) from 4.6 to 12 Nm.
Medical & Biological Engineering & Computing, 2009
In order to reduce the observer variability in radiographic scoliosis assessment, a computer-aide... more In order to reduce the observer variability in radiographic scoliosis assessment, a computer-aided system was developed. The system semi-automatically measured the Cobb angle and vertebral rotation on posteroanterior radiographs based on Hough transform and snake model, respectively. Both algorithms were integrated with the shape priors to improve the performance. The system was tested twice by each of three observers. The intraobserver and interobserver reliability analyses resulted in the intraclass correlation coefficients higher than 0.9 and 0.8 for Cobb measurement on 70 radiographs and rotation measurement on 156 vertebrae, respectively. Both the Cobb and rotation measurements resulted in the average intraobserver and interobserver errors less than 2 degrees and 3 degrees , respectively. There were no significant differences in the measurement variability between groups of curve location, curve magnitude, observer experience, and vertebra location. Compared with the documented results, measurement variability is reduced by using the developed system. This system can help orthopedic surgeons assess scoliosis more reliably.
IEEE Transactions on Instrumentation and Measurement, 2007
This paper describes a low-cost imaging system that is used to quantify the torso deformity that ... more This paper describes a low-cost imaging system that is used to quantify the torso deformity that is associated with scoliosis. The system consists of image-capture and imageanalysis components. The image-capture component obtains fulltorso scans using a rotating positioning platform and one or two surface digitizers. The image-analysis component assesses torso shape. Results of system calibration and error analysis (accuracy of reproduction based on tests on a calibration box, a plaster cast, and a human subject) show that the system can be used to quantify the deformity associated with scoliosis.
Repetitive pointing movements to remembered proprioceptive targets were investigated to determine... more Repetitive pointing movements to remembered proprioceptive targets were investigated to determine whether dynamic proprioception could be used to modify the initial sensorimotor conditions associated with an active definition of the target position. Twelve blindfolded subjects used proprioception to reproduce a self-selected target position as accurately as possible. Ten repetitions for each limb were completed using overhead and scapular plane pointing tasks. A 3D optical tracking system determined hand trajectory start and endpoint positions for each repetition. These positions quantified three-dimensional pointing errors relative to the target position and the initial and preceding movement repetitions, as well as changes in movement direction and extent. Target position and cumulative start position errors were significantly greater than the corresponding preceding movement (inter-repetition) errors, and increased as the trial progressed. In contrast, hand trajectory start and endpoint inter-repetition errors decreased significantly with repeated task performance, as did movement extent, although it was consistently underestimated for each repetition. Pointing direction remained constant, except for the angle of elevation for scapular plane pointing,
The ability of subjects with multidirectional shoulder instability to use proprioception to compl... more The ability of subjects with multidirectional shoulder instability to use proprioception to complete a series of upper limb repositioning tasks was investigated. Twelve subjects with multidirectional instability and 12 control subjects were blindfolded and instructed to use proprioception to reproduce a self-selected target position as accurately as possible. Subjects completed 10 repetitions for each limb using three distinct upper limb movements: overhead reaching, scapular plane pointing, and humeral external rotation with abduction. A three-dimensional video motion analysis system tracked limb position and determined spatial hand position error. Subjects with multidirectional shoulder instability showed significantly greater hand position error than control subjects. No hand position error differences were found between the symptomatic and the asymptomatic limbs of subjects in the instability group. Interrepetition error for subjects in both groups improved significantly during the first three movement cycles. These results suggest that after movement initiation, dynamic proprioception was a factor in improving hand position accuracy in both groups, but to a lesser degree in subjects with multidirectional instability. Consequently, subjects with multidirectional instability may have a reduced capacity to use proprioception to refine and control the motor output of the upper limb.
BackgroundPatients with depression and/or anxiety are commonly seen in inpatient geriatric settin... more BackgroundPatients with depression and/or anxiety are commonly seen in inpatient geriatric settings. Both disorders are associated with an increased risk of cognitive impairments, notably in executive functioning. Transcranial direct current stimulation (tDCS), a type of non-invasive brain stimulation, involves the administration of a low-dose electrical current to induce neuromodulation, which ultimately may act on downstream cognitive processing.ObjectiveThe purpose of this study was to determine the effects of tDCS on executive functioning in geriatric inpatients with symptoms of depression and/or anxiety.DesignPilot Randomized Controlled Trial.SettingSpecialized geriatric wards in a tertiary rehabilitation hospital.MethodsThirty older-aged adults were recruited, of which twenty completed ten-to-fifteen sessions of 1.5 mA anodal or sham tDCS over the left dorsolateral prefrontal cortex. Cognitive assessments were administered at baseline and following the tDCS protocol; analyses ...
Studies in health technology and informatics, 2002
The goal of this pilot study was to explore the relationship between pelvic obliquity and patient... more The goal of this pilot study was to explore the relationship between pelvic obliquity and patient pain, sitting tolerance, pressure sores, and function. Five neuromuscular patients who underwent spinal surgery 6-26 weeks prior to assessment took part in this on-going study (4F; 1M); age at surgery (14.6 +/- 2.6 years). Pelvic obliquity was measured from pre- and post-operative anterior-posterior radiographs. A force-sensing pad with a grid of sensors was placed on a flat surface and the weight distribution pattern was recorded. The pressures were divided into left and right sides and peak levels were noted on each side. The parents or caregivers completed a questionnaire on their child's pain, sitting tolerance, pressure sores, and functional abilities. Pelvic obliquity was reduced after surgery by approximately 50% depending on the method used to assess pelvic obliquity. The major curve was reduced from 64 degrees(10 degrees) to 39 degrees (10 degrees). Post operatively, the average pressure (left/right side) ranged from 1.2 to 2.0 (average 1.6). The peak pressure ratio ranged from 1.1 to 1.9 (average 1.4). The ratio of left/right pressure correlated with improvement in pelvic obliquity (r2=0.9). Pain was moderate/severe in the 2 patients with the least correction as measured with the Cobb angle from surgery; both improved following surgery. Two patients suffered pressure sores pre-operatively and one post-operatively. Only 3/5 felt sitting endurance had increased. All parents felt their child sat straighter after surgery. The outcome measures of pain, pressure sores, sitting tolerance, and function were not well related to the amount of pelvic obliquity. More candidates and a longer follow-up may shed light on the many relationships.
Studies in health technology and informatics, 2002
Kyphosis is an excessive rounding of the upper spine. Its treatment depends upon the severity, th... more Kyphosis is an excessive rounding of the upper spine. Its treatment depends upon the severity, the age of the patient and the levels of the spine that are affected. Early diagnosis is a key to providing optimal treatment. In a skeletally immature patient, an exercise program or bracing is the most commonly used treatment. However, the compliance of bracing for adolescents is poor and exercise training is labor intensive. The purpose of this study is to determine whether a Spine-Straight device can help patients to correct their kyphosis themselves and there by reduce back pain without the biomechanical support of a brace. The Spine-Straight device consists of an accelerometer and a microcomputer unit. The accelerometer is used to measure the kyphotic angle and the microcomputer unit controls a pager vibrator to alert patients when their posture exceeds personalized thresholds. The system was tested in the laboratory before used by subjects. The results were compared to back data obtained from a laser scanner imaging system. The maximum angle deviation between the laser scanner and the Spine-Straight device was 1.5 degrees. Two volunteers tested the systems for 2 days. The accelerometer was placed at the T3 location and the microcomputer unit was carried during daily activities. The angle measurement was recorded at 1 minute intervals during daily activity over a period of 2 days. The preliminary trials demonstrate subjects can improve their posture when feedback signals were provided.
The PVD Bio-Thesiometer was tested as a tool for measuring vibratory thresholds and for detecting... more The PVD Bio-Thesiometer was tested as a tool for measuring vibratory thresholds and for detecting possible differences in these thresholds between adolescents who have idiopathic scoliosis and those who do not. It was found to be limited by low reliability and large errors in measurement, with the metatarsophalangeal joint being the only reliable site for measurement. The vibratory thresholds at this site were significantly higher in the fourteen subjects who had scoliosis than in the twenty-two control subjects. No significant asymmetry in vibratory thresholds was found between the concave and convex or the right and left sides in either the scoliotic or the control group. Because there was no significant difference between the readings from the concave and convex sides, it is unlikely that a lesion of the posterior column is responsible for idiopathic scoliosis. If there is a difference, then the PVD Bio-Thesiometer is not sufficiently reliable to detect it.
In order to study a physiotherapeutic approach to idiopathic scoliosis treatment a posture monito... more In order to study a physiotherapeutic approach to idiopathic scoliosis treatment a posture monitoring system is being built. The system is a small, lightweight, fully portable system capable of monitoring and providing feedback to a patient regarding their posture. Using the combination of accelerometer and electromagnetic technology, distance and angle measurements can be obtained for receivers placed strategically on the patient's back. This data is recorded for further analysis of the patient's progress and to provide immediate feedback to the patient on the status of their posture. Preliminary testing has shown that angular changes of one degree can be detected by the system and that the speed of the electromagnetic field detection has been increased ten times greater than the previous architecture.
The aim of this study was to determine the long-term changes in spine and trunk alignment in pati... more The aim of this study was to determine the long-term changes in spine and trunk alignment in patients who have undergone scoliosis surgery. Twenty-three (16F; 7M; at age of surgery 15.7 +/- 4.9 years) patients with adolescent idiopathic scoliosis agreed to participate and had posterior-anterior radiographs and surface topography prior to derotation surgery, within 6 months of surgery, at 2 years post-operatively and 5-10 years (mean follow-up period 6.11 +/- 1.6 years) after surgery. Cobb angles, surface trunk rotations, and cosmetic scores were measured at each visit. A questionnaire assessed back appearance and pain at the 5-10 year follow-up. The results of the questionnaire were compared to 25 patients with idiopathic scoliosis who had recently undergone surgery. A paired two-tailed Student's t-test with p=0.05 was used to compare the deformity between visits. The Cobb angle and cosmetic score improved after surgery while the change in trunk rotation was insignificant (p=0.37). Between the two-year and 5-10 year review, the Cobb angle, cosmetic score, and surface trunk rotation significantly increased. Self-perception of appearance and pain were similar to the control group. Surgical correction of scoliosis is not completely maintained during adulthood although the radiographic and surface deterioration does not appear to be clinically significant.
To determine the reliability of a prognostic curve progression model and the role of the quantity... more To determine the reliability of a prognostic curve progression model and the role of the quantity and quality of brace wear for adolescent idiopathic scoliosis (AIS) brace treatment. To develop a curve progression model for full-time AIS brace treatment, 20 AIS subjects (Group 1) prescribed full-time thoracolumbar sacral orthosis (TLSO) were monitored and followed for 2 years beyond maturity. The developed curve progression model was: curve progression (in degrees) = 33 + 0.11 × Peterson risk (%) - 0.07 in-brace correction (%) - 0.45 × quality (%) - 0.48 × quantity (%) + 0.0062 × quantity × quality. To validate the model, 40 new (test) subjects (Group 2) who met the same inclusion criteria and used the same type of monitors, were monitored and followed for 2 years after bracing. For the 40 test subjects (Group 2), the average in-brace correction was 40 ± 22 %. The average quantity and quality of the brace wear were 56 ± 19 and 55 ± 17 %, respectively. Twelve subjects (30 %) progressed of which 10 subjects (25 %) required surgery and 28 subjects (70 %) showed no progression. The accuracy of the model to determine which patients would progress was 88 % (35/40) which was better than the Peterson's risk model (68 %; 26/40) alone. Patients who had the combined quantity times the quality over a threshold 43 % had a success treatment rate of 95 %. This study showed the prognostic model of brace treatment outcome on AIS patients treated with full-time TLSO was reliable. Both the quantity and quality of the brace wear were important factors in achieving successful brace treatment.
2006 International Conference of the IEEE Engineering in Medicine and Biology Society, 2006
Many of the aches and pains of adults are the result not of injuries, but of the long-term effect... more Many of the aches and pains of adults are the result not of injuries, but of the long-term effects of distortions in posture or alignment. Postural kyphosis in adolescence may be one of the effects of poor standing and sitting habits. Kyphosis is an excessive rounding of the upper spine. A smart garment that can monitor and provide vibration feedback to children has been developed to investigate an alternative treatment possibility. Laboratory tests verified that the accuracy of the system was +/-2 degrees within the full 180 degrees range. A clinical trial has been conducted and it showed that the system can aid subjects to improve by 20% the proportion of time in a more balanced posture. The long term effect is still under investigation.
IMTC/99. Proceedings of the 16th IEEE Instrumentation and Measurement Technology Conference (Cat. No.99CH36309)
ABSTRACT A battery-powered posture measurement system has been developed to monitor the topograph... more ABSTRACT A battery-powered posture measurement system has been developed to monitor the topographical features of a scoliotic trunk. The system consists of an electromagnetic measurement system and a microcomputer data acquisition system. The polar coordinates of up to 8 receivers relative to the transmitter can be determined. Laboratory tests showed that the maximum distance error was 0.5 cm and the maximum angle error was 5 degrees in the range of 30 to 47 cm. This system is applied to help adolescents who have scoliosis attain a more balanced posture with the use of feedback preliminary clinical trials were done and showed that the system was able to detect the postural changes
Uploads
Papers by Jim Raso