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Research Focus
My research is focused on the physical mechanisms involved in the control
of tissue growth, healing, and homeostasis, especially bone adaptation
and regeneration influenced by mechanical environment, as well as how these mechanisms
can be utilized in the treatment and prevention of disease and injury and bone tissue engineering.
It is clear that bone senses and responds to biomechanical stimuli towards
the achievement and maintenance of a structurally appropriate skeletal
structure. In addition to strain magnitude, bone tissue has the ability
to differentiate between shear and normal strain, cycle number, loading
frequency, and even fluid pressure and its gradients. The interdependent
roles of these mechanical signals are investigated through empiric and
analytic models to provide support for the complex interactive mechanism
of bone remodeling.
My research is also focused on the development of non-invasive scanning
acoustic diagnostic system for tissue quality, and therapeutic ultrasound. The goal of this project
is to develop a new technology, which will lead to a better understanding
of the progressive adaptation of bone loss in aging populations and microgravity
environment. The technology will be used for assessing musculoskeletal
complications such as osteoporosis and accelerate fracture healing.
Fig. 1. Finite element modeling for an implant fixation. Interface
mechanical conditions significantly influence adaptive response of
bone. Surface shear stress plays a critical role in inhibition of
bony ingrowth. |
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Fig. 2. Bone fluid flow is hypothesized a mediator for triggering
cellular response in bone, which is closely related to temporal loading
components, i.e., frequency. Under same strain amplitudes, high frequency
mechanical stimuli (i.e., 30 Hz) raise higher tissue fluid pressure
(10x) than lower frequency (0.1 Hz). |
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Education
- Ph.D. - Mechanical Engineering, SUNY at Stony Brook, 1997
- M.S. - Mechanical Engineering, SUNY at Stony Brook, 1993
Professional Experiences
- 2007 - : Professor of Biomedical Engineering and Orthopaedics,
SUNY Stony Brook
- 2003 - 2007: Assoc. Prof. of Biomedical Engineering and Orthopaedics,
SUNY Stony Brook
- 1998 - 2003: Asst. Prof. of Biomedical Engineering and Orthopaedics,
SUNY Stony Brook
- 1997- 98: Post-Doc. Research Associate, Department of Biomedical
Engineering, Stony Brook.
- 1986-91: Res Scientist & Director, Microstructure Research Laboratory
School of Dental Medicine, Shanghai 2nd Medical University
- 1983-85: Research Fellow, Medical Electronics and Medical Acoustics
Research Lab Institute of Biomedical Engineering, Fudan University
- 1982-86: Biomedical Engineer, Biomedical Engineering Laboratory Shanghai
Medical University
Honors and Awards
- 2002: Chancellor's Award for Promising Inventors, State University
of New York
- 1999-02: Whitaker Investigator, The Whitaker Foundation
- 2000: Recognition Award for Integration of Research and Integration,
SUNY Stony Brook
- 1997: President's Award to Outstanding Doctoral Students, SUNY Stony
Brook
- 1988: Science and Technology Award, Shanghai High Education Department
Funding Sources
- National Space Biomedical Research Institute
- National Institutes of Health
- US Army Medical Research
- The Whitaker Foundation
- New York Advanced Centers for Technology
Publications
Click
here to search Yi-Xian Qin's PubMed listings
Peer-Reviewed Publications
- Qin, Y-X., Kaplan, T., Saldanah, A. and Rubin, C.T.
(2003): Fluid
Pressure Gradients, Arising from Oscillations in Intramedullary Pressure,
is Correlated with the Formation of Bone and Inhibition of Intracortical
Porosity. J Biomech, Oct;36(10):1427-37, 2003.
- Judex S, Boyd S, Qin Y-X, Turner S, Ye K, Muller
R, Rubin C.: Adaptations
of trabecular bone to low magnitude vibrations result in more uniform
stress and strain under load. Ann Biomed Eng., Jan;31(1):12-20,
2003.
- Qin, Y-X., Lin, W., and Rubin, C.T. (2002): The
Pathway of Bone Fluid Flow as Defined by In Vivo Intramedullary Pressure
and Streaming Potential Measurements, Annals Biomed Eng, 30:693-702.
- Qin, Y-X., Kaplan, T., Saldanah, A. and Rubin, C.T. (2002):
Fluid Pressure Gradients, Arising from Oscillations in Intramedullary
Pressure, is Correlated with the Formation of Bone and Inhibition of
Intracortical Porosity. J Biomech, (in press).
- Rubin, C. T., Turner, S., Muller, R., Mittra, E., McLeod, K., Lin,
W., and Qin, Y-X. (2002): Quantity
and Quality of Trabecular Bone in the Femur are Enhanced by a Strongly
Anabolic, Noninvasive Mechanical Intervention. J Bone Min Res, 17(2):
349-357.
- Beck, B., Qin, Y-X., McLeod, K.J. and Otter, M (2002): On
the relationship between streaming potential and strain in an in vivo
bone preparation. Calcif Tiss Intl, 71(4):335-343.
- Lin, W., Qin, Y-X., and Rubin, C.T. (2001): Ultrasonic
Wave Propagation in Trabecular Bone Predicted by the Stratified Model.
Annals Biomed Eng, 29(9): 781-790.
- Rubin, C. T., Sommerfeldt, D. W., Judex, S. and Qin, Y-X. (2001):
Inhibition
of Osteopenia by Low Magnitude, High Frequency Mechanical Stimuli.
Drug Discovery Today, 6:16:848-858.
- Rubin, C.T., Judex, S., McLeod, K.J., Qin, Y-X (2001): Inhibition
of Osteopenia by Biophysical Intervention. In: Osteoporosis. Marcus,
R., Feldman, D., Kelsey, J. (eds.) 2nd edition, Academic Press, San
Diego, CA.
- Qin, Y-X., Lin, W., and Rubin, C.T. (2001): Load-Induced Intracortical
Flow Pathway And Its Potential Role In Bone Adaptation. ASME-BED, 50:
337-338.
- Demes, B., Qin, Y-X., Stern, J. T. Jr., Larson, S. G., Rubin,
C.T. (2001): Patterns
of strain in the macaque tibia during functional activity. Am J
Physcial Anthropology, 116:257-265.
- Qin, Y-X., McLeod, K.J., Otter, M.W. & Rubin, C.T. (2001):
Patterns of Loading Induced Fluid Flow in Cortical Bone, Annals Biomedical
Engineering, (in review).
- Khalsa, P.S., Zhang, C., & Qin, Y-X. (2000): Encoding
of Location and Intensity of Noxious Indentation into Rat Skin by Spatial
Populations of Cutaneous, Mechano-Nociceptors. J. Neurophysiology,
83:3049-3061.
- Otter, M.W., Qin, Y-X., Rubin, C.T. and McLeod, K.J. (1999):
Does
Bone Perfusion/Reperfusion Initiate Bone Remodeling and the Stress Fracture
Syndrome? Medical Hypotheses,53(5):363-368.
- Qin, Y-X., Rubin, C.T., & McLeod, K.J. (1998): Non-linear
Dependence of Loading Intensity and Cycle Number in the Maintenance
of Bone Mass and Morphology. J. Orthop. Res. 16:482-489.
- McLeod, K.J., Rubin, C.T., Otter, M.W. and Qin, Y-X. (1998):
Skeletal
Cell Stresses and Bone Adaptation. Am. J. Med. Sci., 316:176-183.
- Qin, Y., McLeod, K., Otter, M., & Rubin, C. (1997): Intracortical
Pore Fluid Pressure and Gradients Generated by Dynamic Loading and Their
Potential Role in Bone Adaptation. Annals of Biomed. Eng., 25(Suppl.
1):449.
- Fritton, J.C., Rubin, C.T., Qin, Y-X, and McLeod, K.J. (1997): Vibration
in the Skeleton: I. Development of a Resonance-Based Whole Body Vibration
Device. Annals of Biomedical Engineering 25:6.
- Qin, Y-X., McLeod, K.J., Guilak, F., Chiang, F-P and Rubin,
C.T. (1996): Correlation
of Bony Ingrowth to the Distribution of Stress and Strain Parameters
Surrounding a Porous-Coated Implant. J. Ortho. Res. 14:862-870.
- Rubin, C.T., Gross, T., Qin, Y-X.,Fritton, S., Guilak, F.,
and McLeod, K.J. (1996): Differentiation
of the Bone Tissue Remodeling Response to Axial and Torsional Loading
in the Turkey Ulna. J. Bone Joint Surg. 78-A:1523-1533.
- Qin, Y-X., Zhu, L., Young, C. and Hsu, W. (1988): PEF-1 Type
Occlusal Force Meter and Its Clinical Applications. Chinese J. Stomatology,
8:18-22.
- Qin, Y-X., Wang, W., and Shao, Q. (1987): The Method of Ultrasonic
Convergency for the Blood Flow Measurement with Doppler Ultrasound in
the Small Vessel on Oral and Maxillofacial Regions. Chinese J. Biomedic.
Eng., 6:132-136.
Patents and Disclosures
- Qin, Y-X., Lin, W. and Rubin, C.T.: Frequency Scanning of Ultrasound
Attenuation as a Diagnostic to Determine Bone Physical Properties (R-7424).
Patent Pending, 2001.
- Qin, Y-X., Lin, W. and Rubin, C.T.: Method and apparatus for
scanning confocal acoustic diagnostic for bone quality (R-7450). Patent
Pending (Provisional Application #60/271,957), 2001.
- Qin, Y-X., Zhu, L., Young, C. and Hsu, W.: A Transducer with
Piezoelectric Foil for Measuring Forces, Chinese Patent No. 12144, 1988.
- Shao, Q., Qin, Y-X. and Wang, W.: The Stabilizer of Liquid
Flow Velocity Used in a Flow-meter for Measuring Flow Velocity and Quantity,
Chinese Patent No. 1896, 1986.
Selected Abstracts
- Qin, Y-X., Xia, Y., Lin, W., Chadha, A., Gruber, B. and Rubin,
C. (2002): Assessment of bone quantity and quality in human cadaver
calcaneus using scanning confocal ultrasound and DEXA measurements.
Ann Am Soc Bone Mine Res, J Bone Min Res, 17:S422.
- Qin, Y-X., Kaplan, T. (2002): Dose dependence of bone formation
and bone remodeling elucidated by dynamic fluid flow stimulation. Ann
Am Soc Bone Mine Res, J Bone Min Res, 17:S331.
- Mittra, E.S., Rubin, C.T. and Qin, Y-X. (2002): Characterization
of Changes in Trabecular Bone with Age & Disease. Ann Am Soc Bone
Mine Res, J Bone Min Res, 17:S418.
- Qin, Y-X., Mittra, E., Lin, W., Xia, Y., Berman, C. and Rubin,
C. (2002): Non-Invasive Assessment of Bone Quality and Quantity Using
Confocal Acoustic Scanning on ex-vivo Trabeculae. IEEE Eng Med Biol/Ann
Biomed Eng Conference, pp333.
- Lin, W., Mittra, E., Berman, C., Rubin, C. and Qin, Y-X., (2002):
Measurment of ultrasound phase velocity in trabecular bone using adaptive
phase tracking. IEEE Eng Med Biol/Ann Biomed Eng Conference, pp371.
- Mittra, E., Lin, W., C., Rubin, C. and Qin, Y-X., (2002): Interrelationship
of Trabecular Mechanical and Microstructural Properties. IEEE Eng Med
Biol/Ann Biomed Eng Conference, pp156.
- Xia, Y., Lin, W., Chadha, A., Reardon, C., Gruber, B., Rubin, C. and
Qin, Y-X. (2002): Characterization of Human Trabecular bone Quantity
and Quality Using Confocal Acoustic Scanning. IEEE Eng Med Biol/Ann
Biomed Eng Conference, pp371.
- Kaplan, T., Saldanha, A., and Qin, Y-X. (2002): Trabecular
bone formation induced by high frequency, low intensity oscillatory
intramedullary pressure stimulation. IEEE Eng Med Biol/Ann Biomed Eng
Conference, pp160.
- Lai, J.G., Kaplan, T., Saldanha, A., Cute, M., Grine, F.E. and Qin,
Y-X. (2002): Promotion of bony ingrowth by low intensity, high frequency
oscillatory intramedullary pressure stimulation. IEEE Eng Med Biol/Ann
Biomed Eng Conference, pp160.
- Saldanha, A., Qin, Y-X. and Khalsa, P. (2002): Finite element
analysis of mechanical states in human lumbar facet joint capsule. IEEE
Eng Med Biol/Ann Biomed Eng Conference, pp364.
- Qin, Y-X., Lin, W., Gruber, B. and Rubin, C.T. (2002): Ultrasound
assessment for bone quality. NSBRI-NASA Bi-annual Conference, Houston.
- Qin, Y-X., Saldanha, A., Kaplan, T. (2001): Oscillatory Bone
Fluid Flow and its Role in Initiating Remodeling in the Absence of Matrix
Strain. Intl Mech Eng Cong & Eepo, BED-23025, Vol I.
- Lin, W., Rubin, C., Qin, Y. (2001): Measurement of broadband ultrasound
attenuation using tone burst frequency scanning in trabecular bone property
assessment. Intl Mech Eng Cong & Eepo, BED-23033, Vol I.
- Qin, Y-X., Lin, W., and Rubin, C.T. (2001): Interdependent
relationship between Trabecular Bone Quality and Ultrasound Attenuation
and Velocity Using a Scanning Confocol Acoustic Diagnostic System. Ann
Am Soc Bone Mine Res, J Bone Min Res, 16:S470.
- Qin, Y-X., Kaplan, T., Cute, M. and Rubin, C.T. (2001): Dynamic
Fluid Flow Induced Trabecular Bone Formation. Ann Biomed Eng Conference,
Ann Biomed Eng, 29:S-23.
- Saldanha, A., Kaplan, T., Rubin, C.T. and Qin, Y-X. (2001):
Intracortical Fluid Perfusion Patterns under Dynamic Intramedullary
Pressure in a Canine Model. Ann Biomed Eng Conference, Ann Biomed Eng,
29:S-39.
- Lin, W., Rubin, C.T. and Qin, Y-X. (2001): Correlation of Broadband
Ultrasound Attenuation with Trabecular Microstructure. Ann Biomed Eng
Conference, Ann Biomed Eng, 29:S-39.
- Qin, Y-X., Lin, W., and Rubin, C.T. (2001): Load-Induced Intracortical
Flow Pathway And Its Potential Role In Bone Adaptation. Bi-Ann Bioeng
Conference, 50: 337.
- Qin, Y-X., Cute, M., and Rubin, C.T. (2001): The Relationship
between Bone Fluid Flow and Adaptation as Stimulated by Intramedullary
Hydraulic Loading. 47th Ann Mtg Orth Res Soc, 26:319.
- Qin, Y-X., Cute, M., and Rubin, C.T. (2000): Bone Morphological
Adaptation Induced by Dynamic Fluid Flow in the Absence of Matrix Strain.
Annuals Biomed Eng, 28(Sup. 1): S8.
- Lin, W., Qin, Y-X. and Rubin, C.T. (2000): Ultrasound Attenuation
as an Indicator of Bone's Physical Properties. Annals Biomed Eng, 28(Sup.
1): S7.
- Qin, Y-X., McLeod, K.J., and Rubin, C.T. (2000): Intracortical
Fluid Flow is Induced by Dynamic Intramedullary Pressure Independent
of Matrix Deformation. 46th Ann Mtg Orth Res Soc, 25:740.
- Qin, Y-X., Mauser, R., Berman, C., Lin, W. and Rubin, C.T.
(2000): The Relationship between Bone Mineral Density and Ultrasonic
Velocity. 46th Ann Mtg Orth Res Soc, 25:753.
- Lin, W., Qin, Y-X. and Rubin, C.T. (2000): Frequency Specific
Scanning of Ultrasound Attenuation to Measure Bone Properties. 46th
Ann Mtg Orth Res Soc, 25:750.
- Qin, Y-X., McLeod, K.J., Rubin, and C.T. (1999): Intramedullary
Pressure Induced Fluid Flow in Bone. Ann Biomed Eng, p88.
- Qin, Y-X., and Khalsa, P.S. (1999): Lumbar Facet Joint Capsule
Model. Ann Biomed Eng, p91.
- Qin, Y-X., McLeod, K.J., Lin, W., Gray, J., Turner, A.S. and
Rubin, C.T. (1999): Trabeculi Strength Is Enhanced by Low Magnitude
and High Frequency Mechanical Stimuli as Determined by CT Number, Ultrasonic
Velocity and Force-Deformation Measurements. 45th Ann Mtg Orth Res Soc,
24:568.
- Qin, Y-X. and Khalsa, P.S. (1999): Compressive Compliance of
Muscle Emulated with Multi-layer Silicone Substrate. 45th Ann Mtg Orthop
Res Soc, 24:531.
- Lin, W., Qin, Y-X., McLeod, K.J., and Rubin, C.T. (1999): Sinusoidal
Correlation Method in Ultrasound Velocity Measurement of Bone Properties.
45th Ann Mtg Orthop Res Soc, 24:783.
- Lin, W., Gray, J., Qin, Y-X., McLeod, K.J., and Rubin, C.T.
(1998): Assessment of Differential Bone Strength Using Ultrasound Attenuation.
Biomedical Engineering Society, Ann Biomed Eng, 26:S114.
- Qin, Y-X., McLeod, K.J., Otter, M.W. and Rubin, C.T. (1998):
The Interdependence of Loading Frequency and Intracortical Fluid Flow
in Guiding Site-specific Bone Adaptation. Third World Congress of Biomechanics,
Japan.
- Qin, Y-X., McLeod, K.J., Otter, M.W. & Rubin, C.T. (1998):
The Interdependent Role of Loading Frequency, Intracortical Fluid Pressure
and Pressure Gradients in Guiding Site?Specific Bone Adaptation. 44th
Ann Mtg Orthop Res Soc, 23:544.
Research Projects
Bone fluid flow and mechanotransduction
A likely candidate involved in the adaptive process may be the intracortical
fluid pressure and resultant fluid flow which arises in the cortical bone
matrix by the time-varying mechanical strain, which may serve as a critical
signal to regulate cell activity. This hypothesis is evaluated with whole
bone fluid pressure and its gradient in a porous media model incorporated
with in vivo streaming potential measurements. Based on the frequency
dependent site specificity of the remodeling response (i.e., endosteal
vs. periosteal), the most likely parameter which promotes surface new
bone formation may be fluid pressure gradient, factors which are strongly
mediated by loading frequency. Osteocytic processes in the bone could
serve as a mechanical signal receptors by ways of sensing the fluid flow
induced by pressure gradients. Thus, perturbation of intracortical fluid
flow, via alterations in functional activity, may provide a key influence
in determining skeletal morphology. These results may improve our understanding
of functional vertebrate morphology and etiologic processes in musculoskeletal
diseases, and perhaps even provide insight into novel treatment regimens
for the treatment of these diseases (i.e., osteoporosis), the acceleration
of fracture repair, and the promotion of bony ingrowth.
Implant fixation and fracture healing
Bone's ability to respond relatively high frequencies of mechanical stimuli
is indicative as to how bone cells sense the signal for adaptation. This
frequency sensitivity data extends beyond identifying the factor that
stimulates bone formation. Presented result indicates that the most active
inhibitor of bony ingrowth is the shear strain and stress generated at
the bone-implant interface. While specific mechanical parameters, i.e.,
normal strains and strain gradients, may mildly encourage the bony ingrowth,
shear actively inhibits it. To maximally stimulate bony ingrowth, implant
design must promote specific stresses or strains and their gradients,
while minimizing shear stress or strain at the bone-implant interface.
Bioinstrumentation: Noninvasive diagnostic and therapeutic ultrasound
Musculoskeletal complications included osteoporosis and/or the delayed
union of fractures represent a key health problem. Early diagnosis of
these skeletal disorders leads to prompt treatment and will dramatically
reduce the risk of complication. It is hypothesized that such a musculoskeletal
disorder, i.e., osteoporosis, is not only changing the structure and the
mineral density (BMD), but the modulus of the bone. The principal diagnostic
methods for osteoporosis is dual-energy X-ray absorptionmetry (DEXA),
which provides only an index of bone mineral content, and not bone's physical
properties. More recently, advents in ultrasonic techniques provide an
intriguing method for characterizing the material properties of bone in
a manner which is non-invasive, non-destructive, repeatable, safe and
relatively accurate. While ultrasonic techniques provide both structural
and property information of bone, the current research work focus on non-invasively
detect spatial distribution of bone quality in the region of interesting
using the developing scanning acoustic diagnostic system.
Differentiate torsional and axial loading
The ability of bone tissue to differentiate shear and normal strain conditions
was evaluated by monitoring the adaptive response of axial and torsional
loading conditions in a turkey ulna model. Of three distinct regimens
(disuse, axial and torsional loads), only disuse caused a significant
change in gross areal properties as compared to controls (12% loss of
bone), suggesting both axial and torsional loading conditions were suitable
substitutes for functional signals normally responsible for bone homeostasis.
However, the intracortical response was strongly dependent on the manner
in which the bone was loaded. It appears that bone tissue can readily
differentiate between distinct components of the strain environment, with
strain per se necessary to retain coupled formation and resorption, shear
strain achieving this goal by maintaining the status quo, while axial
strain elevates intracortical turnover, but retains coupling.
Frequency, cycle number and loading duration
The interdependent role of loading frequency, cycle number and intensity
was investigated by quantifying the bone remodeling response to a relatively
high frequency (30 Hz) loading regimen. The applied strain distributions
were correlated to site-specific surface modeling/remodeling and intracortical
porosity under long duration loading, following disuse plus 18,000 of
applied loading cycles with peak normal strain of 700, and disuse plus
108,000 applied loading cycles induced at 100. While new bone was found
in the low cycle, high strain magnitude group, the sites correlated poorly
with the distribution of induced strain. However, a strong correlation
was observed between the preservation of bone mass and longitudinal normal
strain (R=0.91) in the high cycle, low strain magnitude group. These results
indicate that mechanical loading can hold anti-resorptive potential, even
at levels less than 100.
Courses
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